/*
* PDKIM - a RFC4871 (DKIM) implementation
*
- * Copyright (C) 2009 Tom Kistner <tom@duncanthrax.net>
+ * Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net>
+ * Copyright (C) 2016 - 2017 Jeremy Harris <jgh@exim.org>
*
* http://duncanthrax.net/pdkim/
*
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-/* $Cambridge: exim/src/src/pdkim/pdkim.c,v 1.5 2009/10/29 10:12:28 tom Exp $ */
+#include "../exim.h"
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <ctype.h>
-#include "pdkim.h"
+#ifndef DISABLE_DKIM /* entire file */
+
+#ifndef SUPPORT_TLS
+# error Need SUPPORT_TLS for DKIM
+#endif
-#include "sha1.h"
-#include "sha2.h"
-#include "rsa.h"
-#include "base64.h"
+#include "crypt_ver.h"
+
+#ifdef SIGN_OPENSSL
+# include <openssl/rsa.h>
+# include <openssl/ssl.h>
+# include <openssl/err.h>
+#elif defined(SIGN_GNUTLS)
+# include <gnutls/gnutls.h>
+# include <gnutls/x509.h>
+#endif
+
+#include "pdkim.h"
+#include "signing.h"
#define PDKIM_SIGNATURE_VERSION "1"
-#define PDKIM_PUB_RECORD_VERSION "DKIM1"
+#define PDKIM_PUB_RECORD_VERSION US "DKIM1"
#define PDKIM_MAX_HEADER_LEN 65536
#define PDKIM_MAX_HEADERS 512
#define PDKIM_MAX_BODY_LINE_LEN 16384
#define PDKIM_DNS_TXT_MAX_NAMELEN 1024
-#define PDKIM_DEFAULT_SIGN_HEADERS "From:Sender:Reply-To:Subject:Date:"\
- "Message-ID:To:Cc:MIME-Version:Content-Type:"\
- "Content-Transfer-Encoding:Content-ID:"\
- "Content-Description:Resent-Date:Resent-From:"\
- "Resent-Sender:Resent-To:Resent-Cc:"\
- "Resent-Message-ID:In-Reply-To:References:"\
- "List-Id:List-Help:List-Unsubscribe:"\
- "List-Subscribe:List-Post:List-Owner:List-Archive"
/* -------------------------------------------------------------------------- */
struct pdkim_stringlist {
- char *value;
- void *next;
-};
-
-#define PDKIM_STR_ALLOC_FRAG 256
-struct pdkim_str {
- char *str;
- unsigned int len;
- unsigned int allocated;
+ uschar * value;
+ int tag;
+ void * next;
};
/* -------------------------------------------------------------------------- */
/* A bunch of list constants */
-char *pdkim_querymethods[] = {
- "dns/txt",
- NULL
-};
-char *pdkim_algos[] = {
- "rsa-sha256",
- "rsa-sha1",
+const uschar * pdkim_querymethods[] = {
+ US"dns/txt",
NULL
};
-char *pdkim_canons[] = {
- "simple",
- "relaxed",
+const uschar * pdkim_canons[] = {
+ US"simple",
+ US"relaxed",
NULL
};
-char *pdkim_hashes[] = {
- "sha256",
- "sha1",
- NULL
+
+typedef struct {
+ const uschar * dkim_hashname;
+ hashmethod exim_hashmethod;
+} pdkim_hashtype;
+static const pdkim_hashtype pdkim_hashes[] = {
+ { US"sha1", HASH_SHA1 },
+ { US"sha256", HASH_SHA2_256 },
+ { US"sha512", HASH_SHA2_512 }
};
-char *pdkim_keytypes[] = {
- "rsa",
- NULL
+
+const uschar * pdkim_keytypes[] = {
+ US"rsa"
};
typedef struct pdkim_combined_canon_entry {
- char *str;
+ const uschar * str;
int canon_headers;
int canon_body;
} pdkim_combined_canon_entry;
+
pdkim_combined_canon_entry pdkim_combined_canons[] = {
- { "simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
- { "simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED },
- { "relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
- { "relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED },
- { "simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
- { "relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
- { NULL, 0, 0 }
+ { US"simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
+ { US"simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED },
+ { US"relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
+ { US"relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED },
+ { US"simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE },
+ { US"relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE },
+ { NULL, 0, 0 }
};
+static blob lineending = {.data = US"\r\n", .len = 2};
+
/* -------------------------------------------------------------------------- */
-/* Print debugging functions */
-#ifdef PDKIM_DEBUG
-void pdkim_quoteprint(FILE *stream, char *data, int len, int lf) {
- int i;
- unsigned char *p = (unsigned char *)data;
-
- for (i=0;i<len;i++) {
- int c = p[i];
- switch (c) {
- case ' ' : fprintf(stream,"{SP}"); break;
- case '\t': fprintf(stream,"{TB}"); break;
- case '\r': fprintf(stream,"{CR}"); break;
- case '\n': fprintf(stream,"{LF}"); break;
- case '{' : fprintf(stream,"{BO}"); break;
- case '}' : fprintf(stream,"{BC}"); break;
- default:
- if ( (c < 32) || (c > 127) )
- fprintf(stream,"{%02x}",c);
- else
- fputc(c,stream);
- break;
- }
- }
- if (lf)
- fputc('\n',stream);
+uschar *
+dkim_sig_to_a_tag(const pdkim_signature * sig)
+{
+if ( sig->keytype < 0 || sig->keytype > nelem(pdkim_keytypes)
+ || sig->hashtype < 0 || sig->hashtype > nelem(pdkim_hashes))
+ return US"err";
+return string_sprintf("%s-%s",
+ pdkim_keytypes[sig->keytype], pdkim_hashes[sig->hashtype].dkim_hashname);
}
-void pdkim_hexprint(FILE *stream, char *data, int len, int lf) {
- int i;
- unsigned char *p = (unsigned char *)data;
- for (i=0;i<len;i++) {
- int c = p[i];
- fprintf(stream,"%02x",c);
+
+
+const char *
+pdkim_verify_status_str(int status)
+{
+switch(status)
+ {
+ case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE";
+ case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID";
+ case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL";
+ case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS";
+ default: return "PDKIM_VERIFY_UNKNOWN";
}
- if (lf)
- fputc('\n',stream);
}
-#endif
-
-/* -------------------------------------------------------------------------- */
-/* Simple string list implementation for convinience */
-pdkim_stringlist *pdkim_append_stringlist(pdkim_stringlist *base, char *str) {
- pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist));
- if (new_entry == NULL) return NULL;
- memset(new_entry,0,sizeof(pdkim_stringlist));
- new_entry->value = strdup(str);
- if (new_entry->value == NULL) return NULL;
- if (base != NULL) {
- pdkim_stringlist *last = base;
- while (last->next != NULL) { last = last->next; };
- last->next = new_entry;
- return base;
+const char *
+pdkim_verify_ext_status_str(int ext_status)
+{
+switch(ext_status)
+ {
+ case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY";
+ case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE";
+ case PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH: return "PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH";
+ case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE";
+ case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE";
+ case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD";
+ case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT";
+ case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: return "PDKIM_VERIFY_INVALID_SIGNATURE_ERROR";
+ case PDKIM_VERIFY_INVALID_DKIM_VERSION: return "PDKIM_VERIFY_INVALID_DKIM_VERSION";
+ default: return "PDKIM_VERIFY_UNKNOWN";
}
- else return new_entry;
-};
-pdkim_stringlist *pdkim_prepend_stringlist(pdkim_stringlist *base, char *str) {
- pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist));
- if (new_entry == NULL) return NULL;
- memset(new_entry,0,sizeof(pdkim_stringlist));
- new_entry->value = strdup(str);
- if (new_entry->value == NULL) return NULL;
- if (base != NULL) {
- new_entry->next = base;
+}
+
+const uschar *
+pdkim_errstr(int status)
+{
+switch(status)
+ {
+ case PDKIM_OK: return US"OK";
+ case PDKIM_FAIL: return US"FAIL";
+ case PDKIM_ERR_RSA_PRIVKEY: return US"RSA_PRIVKEY";
+ case PDKIM_ERR_RSA_SIGNING: return US"RSA SIGNING";
+ case PDKIM_ERR_LONG_LINE: return US"RSA_LONG_LINE";
+ case PDKIM_ERR_BUFFER_TOO_SMALL: return US"BUFFER_TOO_SMALL";
+ case PDKIM_SIGN_PRIVKEY_WRAP: return US"PRIVKEY_WRAP";
+ case PDKIM_SIGN_PRIVKEY_B64D: return US"PRIVKEY_B64D";
+ default: return US"(unknown)";
}
- return new_entry;
-};
+}
/* -------------------------------------------------------------------------- */
-/* A small "growing string" implementation to escape malloc/realloc hell */
-pdkim_str *pdkim_strnew (char *cstr) {
- unsigned int len = cstr?strlen(cstr):0;
- pdkim_str *p = malloc(sizeof(pdkim_str));
- if (p == NULL) return NULL;
- memset(p,0,sizeof(pdkim_str));
- p->str = malloc(len+1);
- if (p->str == NULL) {
- free(p);
- return NULL;
- }
- p->allocated=(len+1);
- p->len=len;
- if (cstr) strcpy(p->str,cstr);
- return p;
-};
-char *pdkim_strncat(pdkim_str *str, char *data, int len) {
- if ((str->allocated - str->len) < (len+1)) {
- /* Extend the buffer */
- int num_frags = ((len+1)/PDKIM_STR_ALLOC_FRAG)+1;
- char *n = realloc(str->str,
- (str->allocated+(num_frags*PDKIM_STR_ALLOC_FRAG)));
- if (n == NULL) return NULL;
- str->str = n;
- str->allocated += (num_frags*PDKIM_STR_ALLOC_FRAG);
- }
- strncpy(&(str->str[str->len]),data,len);
- str->len+=len;
- str->str[str->len] = '\0';
- return str->str;
-};
-char *pdkim_strcat(pdkim_str *str, char *cstr) {
- return pdkim_strncat(str, cstr, strlen(cstr));
-};
-char *pdkim_numcat(pdkim_str *str, unsigned long num) {
- char minibuf[20];
- snprintf(minibuf,20,"%lu",num);
- return pdkim_strcat(str,minibuf);
-};
-char *pdkim_strtrim(pdkim_str *str) {
- char *p = str->str;
- char *q = str->str;
- while ( (*p != '\0') && ((*p == '\t') || (*p == ' ')) ) p++;
- while (*p != '\0') {*q = *p; q++; p++;};
- *q = '\0';
- while ( (q != str->str) && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) ) {
- *q = '\0';
- q--;
+/* Print debugging functions */
+static void
+pdkim_quoteprint(const uschar *data, int len)
+{
+int i;
+for (i = 0; i < len; i++)
+ {
+ const int c = data[i];
+ switch (c)
+ {
+ case ' ' : debug_printf("{SP}"); break;
+ case '\t': debug_printf("{TB}"); break;
+ case '\r': debug_printf("{CR}"); break;
+ case '\n': debug_printf("{LF}"); break;
+ case '{' : debug_printf("{BO}"); break;
+ case '}' : debug_printf("{BC}"); break;
+ default:
+ if ( (c < 32) || (c > 127) )
+ debug_printf("{%02x}", c);
+ else
+ debug_printf("%c", c);
+ break;
+ }
}
- str->len = strlen(str->str);
- return str->str;
-};
-char *pdkim_strclear(pdkim_str *str) {
- str->str[0] = '\0';
- str->len = 0;
- return str->str;
-};
-void pdkim_strfree(pdkim_str *str) {
- if (str == NULL) return;
- if (str->str != NULL) free(str->str);
- free(str);
-};
+debug_printf("\n");
+}
+static void
+pdkim_hexprint(const uschar *data, int len)
+{
+int i;
+if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+else debug_printf("<NULL>");
+debug_printf("\n");
+}
-/* -------------------------------------------------------------------------- */
-void pdkim_free_pubkey(pdkim_pubkey *pub) {
- if (pub) {
- if (pub->version != NULL) free(pub->version);
- if (pub->granularity != NULL) free(pub->granularity);
- if (pub->hashes != NULL) free(pub->hashes);
- if (pub->keytype != NULL) free(pub->keytype);
- if (pub->srvtype != NULL) free(pub->srvtype);
- if (pub->notes != NULL) free(pub->notes);
- if (pub->key != NULL) free(pub->key);
- free(pub);
- }
+
+static pdkim_stringlist *
+pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str)
+{
+pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist));
+
+memset(new_entry, 0, sizeof(pdkim_stringlist));
+new_entry->value = string_copy(str);
+if (base) new_entry->next = base;
+return new_entry;
}
-/* -------------------------------------------------------------------------- */
-void pdkim_free_sig(pdkim_signature *sig) {
- if (sig) {
- pdkim_signature *next = (pdkim_signature *)sig->next;
-
- pdkim_stringlist *e = sig->headers;
- while(e != NULL) {
- pdkim_stringlist *c = e;
- if (e->value != NULL) free(e->value);
- e = e->next;
- free(c);
- }
- if (sig->sigdata != NULL) free(sig->sigdata);
- if (sig->bodyhash != NULL) free(sig->bodyhash);
- if (sig->selector != NULL) free(sig->selector);
- if (sig->domain != NULL) free(sig->domain);
- if (sig->identity != NULL) free(sig->identity);
- if (sig->headernames != NULL) free(sig->headernames);
- if (sig->copiedheaders != NULL) free(sig->copiedheaders);
- if (sig->rsa_privkey != NULL) free(sig->rsa_privkey);
- if (sig->sign_headers != NULL) free(sig->sign_headers);
- if (sig->signature_header != NULL) free(sig->signature_header);
- if (sig->sha1_body != NULL) free(sig->sha1_body);
- if (sig->sha2_body != NULL) free(sig->sha2_body);
- if (sig->hnames_check != NULL) free(sig->hnames_check);
-
- if (sig->pubkey != NULL) pdkim_free_pubkey(sig->pubkey);
-
- free(sig);
- if (next != NULL) pdkim_free_sig(next);
- }
-};
+/* Trim whitespace fore & aft */
+
+static void
+pdkim_strtrim(gstring * str)
+{
+uschar * p = str->s;
+uschar * q = p + str->ptr;
+
+while (*p == '\t' || *p == ' ') /* dump the leading whitespace */
+ { str->size--; str->ptr--; str->s++; }
+
+while ( str->ptr > 0
+ && (q = str->s + str->ptr - 1), *q == '\t' || *q == ' '
+ )
+ str->ptr--; /* dump trailing whitespace */
+
+(void) string_from_gstring(str);
+}
+
/* -------------------------------------------------------------------------- */
-DLLEXPORT void pdkim_free_ctx(pdkim_ctx *ctx) {
- if (ctx) {
- pdkim_free_sig(ctx->sig);
- pdkim_strfree(ctx->cur_header);
- free(ctx);
- }
-};
+
+DLLEXPORT void
+pdkim_free_ctx(pdkim_ctx *ctx)
+{
+}
/* -------------------------------------------------------------------------- */
/* Matches the name of the passed raw "header" against
- the passed colon-separated "list", starting at entry
- "start". Returns the position of the header name in
- the list. */
-int header_name_match(char *header,
- char *tick,
- int do_tick) {
- char *hname;
- char *lcopy;
- char *p;
- char *q;
- int rc = PDKIM_FAIL;
-
- /* Get header name */
- char *hcolon = strchr(header,':');
- if (hcolon == NULL) return rc; /* This isn't a header */
- hname = malloc((hcolon-header)+1);
- if (hname == NULL) return PDKIM_ERR_OOM;
- memset(hname,0,(hcolon-header)+1);
- strncpy(hname,header,(hcolon-header));
-
- /* Copy tick-off list locally, so we can punch zeroes into it */
- lcopy = strdup(tick);
- if (lcopy == NULL) {
- free(hname);
- return PDKIM_ERR_OOM;
- }
- p = lcopy;
- q = strchr(p,':');
- while (q != NULL) {
- *q = '\0';
-
- if (strcasecmp(p,hname) == 0) {
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- if (do_tick) tick[p-lcopy] = '_';
- goto BAIL;
- }
+ the passed colon-separated "tick", and invalidates
+ the entry in tick. Returns OK or fail-code */
+/*XXX might be safer done using a pdkim_stringlist for "tick" */
+
+static int
+header_name_match(const uschar * header, uschar * tick)
+{
+uschar * hname;
+uschar * lcopy;
+uschar * p;
+uschar * q;
+uschar * hcolon = Ustrchr(header, ':'); /* Get header name */
+
+if (!hcolon)
+ return PDKIM_FAIL; /* This isn't a header */
+
+/* if we had strncmpic() we wouldn't need this copy */
+hname = string_copyn(header, hcolon-header);
+
+/* Copy tick-off list locally, so we can punch zeroes into it */
+p = lcopy = string_copy(tick);
+
+for (q = Ustrchr(p, ':'); q; q = Ustrchr(p, ':'))
+ {
+ *q = '\0';
+ if (strcmpic(p, hname) == 0)
+ goto found;
- p = q+1;
- q = strchr(p,':');
+ p = q+1;
}
- if (strcasecmp(p,hname) == 0) {
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- if (do_tick) tick[p-lcopy] = '_';
- }
+if (strcmpic(p, hname) == 0)
+ goto found;
+
+return PDKIM_FAIL;
- BAIL:
- free(hname);
- free(lcopy);
- return rc;
+found:
+ /* Invalidate header name instance in tick-off list */
+ tick[p-lcopy] = '_';
+ return PDKIM_OK;
}
/* -------------------------------------------------------------------------- */
-/* Performs "relaxed" canonicalization of a header. The returned pointer needs
- to be free()d. */
-char *pdkim_relax_header (char *header, int crlf) {
- int past_field_name = 0;
- int seen_wsp = 0;
- char *p = header;
- char *q;
- char *relaxed = malloc(strlen(header)+3);
- if (relaxed == NULL) return NULL;
- q = relaxed;
- while (*p != '\0') {
- int c = *p;
- /* Ignore CR & LF */
- if ( (c == '\r') || (c == '\n') ) {
- p++;
+/* Performs "relaxed" canonicalization of a header. */
+
+static uschar *
+pdkim_relax_header(const uschar * header, BOOL append_crlf)
+{
+BOOL past_field_name = FALSE;
+BOOL seen_wsp = FALSE;
+const uschar * p;
+uschar * relaxed = store_get(Ustrlen(header)+3);
+uschar * q = relaxed;
+
+for (p = header; *p; p++)
+ {
+ uschar c = *p;
+
+ if (c == '\r' || c == '\n') /* Ignore CR & LF */
+ continue;
+ if (c == '\t' || c == ' ')
+ {
+ if (seen_wsp)
continue;
+ c = ' '; /* Turns WSP into SP */
+ seen_wsp = TRUE;
}
- if ( (c == '\t') || (c == ' ') ) {
- c = ' '; /* Turns WSP into SP */
- if (seen_wsp) {
- p++;
- continue;
+ else
+ if (!past_field_name && c == ':')
+ {
+ if (seen_wsp) q--; /* This removes WSP immediately before the colon */
+ seen_wsp = TRUE; /* This removes WSP immediately after the colon */
+ past_field_name = TRUE;
}
- else seen_wsp = 1;
- }
- else {
- if ( (!past_field_name) && (c == ':') ) {
- if (seen_wsp) q--; /* This removes WSP before the colon */
- seen_wsp = 1; /* This removes WSP after the colon */
- past_field_name = 1;
- }
- else seen_wsp = 0;
- }
- /* Lowercase header name */
- if (!past_field_name) c = tolower(c);
- *q = c;
- p++;
- q++;
+ else
+ seen_wsp = FALSE;
+
+ /* Lowercase header name */
+ if (!past_field_name) c = tolower(c);
+ *q++ = c;
}
- *q = '\0';
- if (crlf) strcat(relaxed,"\r\n");
- return relaxed;
-};
+
+if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */
+
+if (append_crlf) { *q++ = '\r'; *q++ = '\n'; }
+*q = '\0';
+return relaxed;
+}
/* -------------------------------------------------------------------------- */
#define PDKIM_QP_ERROR_DECODE -1
-char *pdkim_decode_qp_char(char *qp_p, int *c) {
- char *initial_pos = qp_p;
-
- /* Advance one char */
- qp_p++;
-
- /* Check for two hex digits and decode them */
- if (isxdigit(*qp_p) && isxdigit(qp_p[1])) {
- /* Do hex conversion */
- if (isdigit(*qp_p)) {*c = *qp_p - '0';}
- else {*c = toupper(*qp_p) - 'A' + 10;};
- *c <<= 4;
- if (isdigit(qp_p[1])) {*c |= qp_p[1] - '0';}
- else {*c |= toupper(qp_p[1]) - 'A' + 10;};
- return qp_p + 2;
- };
-
- /* Illegal char here */
- *c = PDKIM_QP_ERROR_DECODE;
- return initial_pos;
+
+static const uschar *
+pdkim_decode_qp_char(const uschar *qp_p, int *c)
+{
+const uschar *initial_pos = qp_p;
+
+/* Advance one char */
+qp_p++;
+
+/* Check for two hex digits and decode them */
+if (isxdigit(*qp_p) && isxdigit(qp_p[1]))
+ {
+ /* Do hex conversion */
+ *c = (isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10) << 4;
+ *c |= isdigit(qp_p[1]) ? qp_p[1] - '0' : toupper(qp_p[1]) - 'A' + 10;
+ return qp_p + 2;
+ }
+
+/* Illegal char here */
+*c = PDKIM_QP_ERROR_DECODE;
+return initial_pos;
}
/* -------------------------------------------------------------------------- */
-char *pdkim_decode_qp(char *str) {
- int nchar = 0;
- char *q;
- char *p = str;
- char *n = malloc(strlen(p)+1);
- if (n == NULL) return NULL;
- *n = '\0';
- q = n;
- while (*p != '\0') {
- if (*p == '=') {
- p = pdkim_decode_qp_char(p,&nchar);
- if (nchar >= 0) {
- *q = nchar;
- q++;
- continue;
+
+static uschar *
+pdkim_decode_qp(const uschar * str)
+{
+int nchar = 0;
+uschar * q;
+const uschar * p = str;
+uschar * n = store_get(Ustrlen(str)+1);
+
+*n = '\0';
+q = n;
+while (*p)
+ {
+ if (*p == '=')
+ {
+ p = pdkim_decode_qp_char(p, &nchar);
+ if (nchar >= 0)
+ {
+ *q++ = nchar;
+ continue;
}
}
- else {
- *q = *p;
- q++;
- }
- p++;
+ else
+ *q++ = *p;
+ p++;
}
- *q = '\0';
- return n;
+*q = '\0';
+return n;
}
/* -------------------------------------------------------------------------- */
-char *pdkim_decode_base64(char *str, int *num_decoded) {
- int dlen = 0;
- char *res;
-
- base64_decode(NULL, &dlen, (unsigned char *)str, strlen(str));
- res = malloc(dlen+1);
- if (res == NULL) return NULL;
- if (base64_decode((unsigned char *)res,&dlen,(unsigned char *)str,strlen(str)) != 0) {
- free(res);
- return NULL;
- }
- if (num_decoded != NULL) *num_decoded = dlen;
- return res;
+
+static void
+pdkim_decode_base64(const uschar * str, blob * b)
+{
+int dlen;
+dlen = b64decode(str, &b->data);
+if (dlen < 0) b->data = NULL;
+b->len = dlen;
}
-/* -------------------------------------------------------------------------- */
-char *pdkim_encode_base64(char *str, int num) {
- int dlen = 0;
- char *res;
-
- base64_encode(NULL, &dlen, (unsigned char *)str, num);
- res = malloc(dlen+1);
- if (res == NULL) return NULL;
- if (base64_encode((unsigned char *)res,&dlen,(unsigned char *)str,num) != 0) {
- free(res);
- return NULL;
- }
- return res;
+static uschar *
+pdkim_encode_base64(blob * b)
+{
+return b64encode(b->data, b->len);
}
#define PDKIM_HDR_LIMBO 0
#define PDKIM_HDR_TAG 1
#define PDKIM_HDR_VALUE 2
-pdkim_signature *pdkim_parse_sig_header(pdkim_ctx *ctx, char *raw_hdr) {
- pdkim_signature *sig ;
- char *p,*q;
- pdkim_str *cur_tag = NULL;
- pdkim_str *cur_val = NULL;
- int past_hname = 0;
- int in_b_val = 0;
- int where = PDKIM_HDR_LIMBO;
- int i;
-
- sig = malloc(sizeof(pdkim_signature));
- if (sig == NULL) return NULL;
- memset(sig,0,sizeof(pdkim_signature));
- sig->bodylength = -1;
-
- sig->rawsig_no_b_val = malloc(strlen(raw_hdr)+1);
- if (sig->rawsig_no_b_val == NULL) {
- free(sig);
- return NULL;
- }
-
- p = raw_hdr;
- q = sig->rawsig_no_b_val;
- while (1) {
+static pdkim_signature *
+pdkim_parse_sig_header(pdkim_ctx * ctx, uschar * raw_hdr)
+{
+pdkim_signature * sig;
+uschar *p, *q;
+gstring * cur_tag = NULL;
+gstring * cur_val = NULL;
+BOOL past_hname = FALSE;
+BOOL in_b_val = FALSE;
+int where = PDKIM_HDR_LIMBO;
+int i;
+
+sig = store_get(sizeof(pdkim_signature));
+memset(sig, 0, sizeof(pdkim_signature));
+sig->bodylength = -1;
+
+/* Set so invalid/missing data error display is accurate */
+sig->version = 0;
+sig->keytype = -1;
+sig->hashtype = -1;
+
+q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1);
+
+for (p = raw_hdr; ; p++)
+ {
+ char c = *p;
+
+ /* Ignore FWS */
+ if (c == '\r' || c == '\n')
+ goto NEXT_CHAR;
+
+ /* Fast-forward through header name */
+ if (!past_hname)
+ {
+ if (c == ':') past_hname = TRUE;
+ goto NEXT_CHAR;
+ }
- /* Ignore FWS */
- if ( (*p == '\r') || (*p == '\n') )
+ if (where == PDKIM_HDR_LIMBO)
+ {
+ /* In limbo, just wait for a tag-char to appear */
+ if (!(c >= 'a' && c <= 'z'))
goto NEXT_CHAR;
- /* Fast-forward through header name */
- if (!past_hname) {
- if (*p == ':') past_hname = 1;
- goto NEXT_CHAR;
+ where = PDKIM_HDR_TAG;
}
- if (where == PDKIM_HDR_LIMBO) {
- /* In limbo, just wait for a tag-char to appear */
- if (!((*p >= 'a') && (*p <= 'z')))
- goto NEXT_CHAR;
-
- where = PDKIM_HDR_TAG;
+ if (where == PDKIM_HDR_TAG)
+ {
+ if (c >= 'a' && c <= 'z')
+ cur_tag = string_catn(cur_tag, p, 1);
+
+ if (c == '=')
+ {
+ if (Ustrcmp(string_from_gstring(cur_tag), "b") == 0)
+ {
+ *q++ = '=';
+ in_b_val = TRUE;
+ }
+ where = PDKIM_HDR_VALUE;
+ goto NEXT_CHAR;
+ }
}
- if (where == PDKIM_HDR_TAG) {
- if (cur_tag == NULL)
- cur_tag = pdkim_strnew(NULL);
-
- if ((*p >= 'a') && (*p <= 'z'))
- pdkim_strncat(cur_tag,p,1);
+ if (where == PDKIM_HDR_VALUE)
+ {
+ if (c == '\r' || c == '\n' || c == ' ' || c == '\t')
+ goto NEXT_CHAR;
- if (*p == '=') {
- if (strcmp(cur_tag->str,"b") == 0) {
- *q = '='; q++;
- in_b_val = 1;
- }
- where = PDKIM_HDR_VALUE;
- goto NEXT_CHAR;
+ if (c == ';' || c == '\0')
+ {
+ if (cur_tag && cur_val)
+ {
+ (void) string_from_gstring(cur_val);
+ pdkim_strtrim(cur_val);
+
+ DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->s, cur_val->s);
+
+ switch (*cur_tag->s)
+ {
+ case 'b':
+ pdkim_decode_base64(cur_val->s,
+ cur_tag->s[1] == 'h' ? &sig->bodyhash : &sig->sighash);
+ break;
+ case 'v':
+ /* We only support version 1, and that is currently the
+ only version there is. */
+ sig->version =
+ Ustrcmp(cur_val->s, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1;
+ break;
+ case 'a':
+ {
+ uschar * s = Ustrchr(cur_val->s, '-');
+
+ for(i = 0; i < nelem(pdkim_keytypes); i++)
+ if (Ustrncmp(cur_val->s, pdkim_keytypes[i], s - cur_val->s) == 0)
+ { sig->keytype = i; break; }
+ for (++s, i = 0; i < nelem(pdkim_hashes); i++)
+ if (Ustrcmp(s, pdkim_hashes[i].dkim_hashname) == 0)
+ { sig->hashtype = i; break; }
+ break;
+ }
+
+ case 'c':
+ for (i = 0; pdkim_combined_canons[i].str; i++)
+ if (Ustrcmp(cur_val->s, pdkim_combined_canons[i].str) == 0)
+ {
+ sig->canon_headers = pdkim_combined_canons[i].canon_headers;
+ sig->canon_body = pdkim_combined_canons[i].canon_body;
+ break;
+ }
+ break;
+ case 'q':
+ for (i = 0; pdkim_querymethods[i]; i++)
+ if (Ustrcmp(cur_val->s, pdkim_querymethods[i]) == 0)
+ {
+ sig->querymethod = i;
+ break;
+ }
+ break;
+ case 's':
+ sig->selector = string_copyn(cur_val->s, cur_val->ptr); break;
+ case 'd':
+ sig->domain = string_copyn(cur_val->s, cur_val->ptr); break;
+ case 'i':
+ sig->identity = pdkim_decode_qp(cur_val->s); break;
+ case 't':
+ sig->created = strtoul(CS cur_val->s, NULL, 10); break;
+ case 'x':
+ sig->expires = strtoul(CS cur_val->s, NULL, 10); break;
+ case 'l':
+ sig->bodylength = strtol(CS cur_val->s, NULL, 10); break;
+ case 'h':
+ sig->headernames = string_copyn(cur_val->s, cur_val->ptr); break;
+ case 'z':
+ sig->copiedheaders = pdkim_decode_qp(cur_val->s); break;
+ default:
+ DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
+ break;
+ }
+ }
+ cur_tag = cur_val = NULL;
+ in_b_val = FALSE;
+ where = PDKIM_HDR_LIMBO;
}
+ else
+ cur_val = string_catn(cur_val, p, 1);
}
- if (where == PDKIM_HDR_VALUE) {
- if (cur_val == NULL)
- cur_val = pdkim_strnew(NULL);
-
- if ( (*p == '\r') || (*p == '\n') || (*p == ' ') || (*p == '\t') )
- goto NEXT_CHAR;
-
- if ( (*p == ';') || (*p == '\0') ) {
- if (cur_tag->len > 0) {
- pdkim_strtrim(cur_val);
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream, "%s=%s\n", cur_tag->str, cur_val->str);
- #endif
- switch (cur_tag->str[0]) {
- case 'b':
- switch (cur_tag->str[1]) {
- case 'h':
- sig->bodyhash = pdkim_decode_base64(cur_val->str,&(sig->bodyhash_len));
- break;
- default:
- sig->sigdata = pdkim_decode_base64(cur_val->str,&(sig->sigdata_len));
- break;
- }
- break;
- case 'v':
- if (strcmp(cur_val->str,PDKIM_SIGNATURE_VERSION) == 0) {
- /* We only support version 1, and that is currently the
- only version there is. */
- sig->version = 1;
- }
- break;
- case 'a':
- i = 0;
- while (pdkim_algos[i] != NULL) {
- if (strcmp(cur_val->str,pdkim_algos[i]) == 0 ) {
- sig->algo = i;
- break;
- }
- i++;
- }
- break;
- case 'c':
- i = 0;
- while (pdkim_combined_canons[i].str != NULL) {
- if (strcmp(cur_val->str,pdkim_combined_canons[i].str) == 0 ) {
- sig->canon_headers = pdkim_combined_canons[i].canon_headers;
- sig->canon_body = pdkim_combined_canons[i].canon_body;
- break;
- }
- i++;
- }
- break;
- case 'q':
- i = 0;
- while (pdkim_querymethods[i] != NULL) {
- if (strcmp(cur_val->str,pdkim_querymethods[i]) == 0 ) {
- sig->querymethod = i;
- break;
- }
- i++;
- }
- break;
- case 's':
- sig->selector = strdup(cur_val->str);
- break;
- case 'd':
- sig->domain = strdup(cur_val->str);
- break;
- case 'i':
- sig->identity = pdkim_decode_qp(cur_val->str);
- break;
- case 't':
- sig->created = strtoul(cur_val->str,NULL,10);
- break;
- case 'x':
- sig->expires = strtoul(cur_val->str,NULL,10);
- break;
- case 'l':
- sig->bodylength = strtol(cur_val->str,NULL,10);
- break;
- case 'h':
- sig->headernames = strdup(cur_val->str);
- break;
- case 'z':
- sig->copiedheaders = pdkim_decode_qp(cur_val->str);
- break;
- default:
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream, "Unknown tag encountered\n");
- #endif
- break;
- }
- }
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
- in_b_val = 0;
- where = PDKIM_HDR_LIMBO;
- goto NEXT_CHAR;
- }
- else pdkim_strncat(cur_val,p,1);
- }
+NEXT_CHAR:
+ if (c == '\0')
+ break;
- NEXT_CHAR:
- if (*p == '\0') break;
+ if (!in_b_val)
+ *q++ = c;
+ }
- if (!in_b_val) {
- *q = *p;
- q++;
- }
- p++;
+*q = '\0';
+/* Chomp raw header. The final newline must not be added to the signature. */
+while (--q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n'))
+ *q = '\0';
+
+DEBUG(D_acl)
+ {
+ debug_printf(
+ "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val));
+ debug_printf(
+ "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sighash.len*8);
+ debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- /* Make sure the most important bits are there. */
- if (!(sig->domain && (*(sig->domain) != '\0') &&
- sig->selector && (*(sig->selector) != '\0') &&
- sig->headernames && (*(sig->headernames) != '\0') &&
- sig->bodyhash &&
- sig->sigdata &&
- sig->version)) {
- pdkim_free_sig(sig);
- return NULL;
+/*XXX hash method: extend for sha512 */
+if (!exim_sha_init(&sig->body_hash_ctx,
+ pdkim_hashes[sig->hashtype].exim_hashmethod))
+ {
+ DEBUG(D_acl)
+ debug_printf("PDKIM: hash init error, possibly nonhandled hashtype\n");
+ return NULL;
}
+return sig;
+}
- /* Copy header list to 'tick-off' header list */
- sig->hnames_check = strdup(sig->headernames);
- *q = '\0';
- /* Chomp raw header. The final newline must not be added to the signature. */
- q--;
- while( (q > sig->rawsig_no_b_val) && ((*q == '\r') || (*q == '\n')) ) {
- *q = '\0'; q--;
- }
+/* -------------------------------------------------------------------------- */
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,
- "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- pdkim_quoteprint(ctx->debug_stream,
- sig->rawsig_no_b_val,
- strlen(sig->rawsig_no_b_val), 1);
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+static pdkim_pubkey *
+pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record)
+{
+const uschar * ele;
+int sep = ';';
+pdkim_pubkey * pub;
+
+pub = store_get(sizeof(pdkim_pubkey));
+memset(pub, 0, sizeof(pdkim_pubkey));
+
+while ((ele = string_nextinlist(&raw_record, &sep, NULL, 0)))
+ {
+ const uschar * val;
+
+ if ((val = Ustrchr(ele, '=')))
+ {
+ int taglen = val++ - ele;
+
+ DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, ele, val);
+ switch (ele[0])
+ {
+ case 'v': pub->version = val; break;
+ case 'h': pub->hashes = val; break;
+ case 'k': break;
+ case 'g': pub->granularity = val; break;
+ case 'n': pub->notes = pdkim_decode_qp(val); break;
+ case 'p': pdkim_decode_base64(val, &pub->key); break;
+ case 's': pub->srvtype = val; break;
+ case 't': if (Ustrchr(val, 'y')) pub->testing = 1;
+ if (Ustrchr(val, 's')) pub->no_subdomaining = 1;
+ break;
+ default: DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); break;
+ }
+ }
}
- #endif
- sig->sha1_body = malloc(sizeof(sha1_context));
- if (sig->sha1_body == NULL) {
- pdkim_free_sig(sig);
- return NULL;
- }
- sig->sha2_body = malloc(sizeof(sha2_context));
- if (sig->sha2_body == NULL) {
- pdkim_free_sig(sig);
- return NULL;
+/* Set fallback defaults */
+if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION);
+else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0)
+ {
+ DEBUG(D_acl) debug_printf(" Bad v= field\n");
+ return NULL;
}
- sha1_starts(sig->sha1_body);
- sha2_starts(sig->sha2_body,0);
+if (!pub->granularity) pub->granularity = US"*";
+/*
+if (!pub->keytype ) pub->keytype = US"rsa";
+*/
+if (!pub->srvtype ) pub->srvtype = US"*";
- return sig;
+/* p= is required */
+if (pub->key.data)
+ return pub;
+
+DEBUG(D_acl) debug_printf(" Missing p= field\n");
+return NULL;
}
/* -------------------------------------------------------------------------- */
-pdkim_pubkey *pdkim_parse_pubkey_record(pdkim_ctx *ctx, char *raw_record) {
- pdkim_pubkey *pub ;
- char *p;
- pdkim_str *cur_tag = NULL;
- pdkim_str *cur_val = NULL;
- int where = PDKIM_HDR_LIMBO;
- pub = malloc(sizeof(pdkim_pubkey));
- if (pub == NULL) return NULL;
- memset(pub,0,sizeof(pdkim_pubkey));
+/* Update the bodyhash for one sig, with some additional data.
+If we have to relax the data for this sig, return our copy of it. */
+
+/*XXX Currently we calculate a hash for each sig. But it is possible
+that multi-signing will be wanted using different signing algos
+(rsa, ec) using the same hash and canonicalization. Consider in future
+hanging the hash+cacnon from the ctx and only referencing from the sig,
+so that it can be calculated only once - being over the body this
+caould be meagbytes, hence expensive. */
+
+static blob *
+pdkim_update_sig_bodyhash(pdkim_signature * sig, blob * orig_data, blob * relaxed_data)
+{
+blob * canon_data = orig_data;
+/* Defaults to simple canon (no further treatment necessary) */
+
+if (sig->canon_body == PDKIM_CANON_RELAXED)
+ {
+ /* Relax the line if not done already */
+ if (!relaxed_data)
+ {
+ BOOL seen_wsp = FALSE;
+ const uschar * p;
+ int q = 0;
+
+ /* We want to be able to free this else we allocate
+ for the entire message which could be many MB. Since
+ we don't know what allocations the SHA routines might
+ do, not safe to use store_get()/store_reset(). */
+
+ relaxed_data = store_malloc(sizeof(blob) + orig_data->len+1);
+ relaxed_data->data = US (relaxed_data+1);
+
+ for (p = orig_data->data; *p; p++)
+ {
+ char c = *p;
+ if (c == '\r')
+ {
+ if (q > 0 && relaxed_data->data[q-1] == ' ')
+ q--;
+ }
+ else if (c == '\t' || c == ' ')
+ {
+ c = ' '; /* Turns WSP into SP */
+ if (seen_wsp)
+ continue;
+ seen_wsp = TRUE;
+ }
+ else
+ seen_wsp = FALSE;
+ relaxed_data->data[q++] = c;
+ }
+ relaxed_data->data[q] = '\0';
+ relaxed_data->len = q;
+ }
+ canon_data = relaxed_data;
+ }
- p = raw_record;
+/* Make sure we don't exceed the to-be-signed body length */
+if ( sig->bodylength >= 0
+ && sig->signed_body_bytes + (unsigned long)canon_data->len > sig->bodylength
+ )
+ canon_data->len = sig->bodylength - sig->signed_body_bytes;
+
+if (canon_data->len > 0)
+ {
+ exim_sha_update(&sig->body_hash_ctx, CUS canon_data->data, canon_data->len);
+ sig->signed_body_bytes += canon_data->len;
+ DEBUG(D_acl) pdkim_quoteprint(canon_data->data, canon_data->len);
+ }
- while (1) {
+return relaxed_data;
+}
- /* Ignore FWS */
- if ( (*p == '\r') || (*p == '\n') )
- goto NEXT_CHAR;
- if (where == PDKIM_HDR_LIMBO) {
- /* In limbo, just wait for a tag-char to appear */
- if (!((*p >= 'a') && (*p <= 'z')))
- goto NEXT_CHAR;
+/* -------------------------------------------------------------------------- */
- where = PDKIM_HDR_TAG;
+static void
+pdkim_finish_bodyhash(pdkim_ctx * ctx)
+{
+pdkim_signature * sig;
+
+/* Traverse all signatures */
+for (sig = ctx->sig; sig; sig = sig->next)
+ { /* Finish hashes */
+ blob bh;
+
+ exim_sha_finish(&sig->body_hash_ctx, &bh);
+
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM [%s] Body bytes hashed: %lu\n"
+ "PDKIM [%s] Body %s computed: ",
+ sig->domain, sig->signed_body_bytes,
+ sig->domain, pdkim_hashes[sig->hashtype].dkim_hashname);
+ pdkim_hexprint(CUS bh.data, bh.len);
}
- if (where == PDKIM_HDR_TAG) {
- if (cur_tag == NULL)
- cur_tag = pdkim_strnew(NULL);
+ /* SIGNING -------------------------------------------------------------- */
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ {
+ sig->bodyhash = bh;
+
+ /* If bodylength limit is set, and we have received less bytes
+ than the requested amount, effectively remove the limit tag. */
+ if (sig->signed_body_bytes < sig->bodylength)
+ sig->bodylength = -1;
+ }
- if ((*p >= 'a') && (*p <= 'z'))
- pdkim_strncat(cur_tag,p,1);
+ else
+ /* VERIFICATION --------------------------------------------------------- */
+ /* Be careful that the header sig included a bodyash */
- if (*p == '=') {
- where = PDKIM_HDR_VALUE;
- goto NEXT_CHAR;
+ if (sig->bodyhash.data && memcmp(bh.data, sig->bodyhash.data, bh.len) == 0)
+ {
+ DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain);
}
- }
-
- if (where == PDKIM_HDR_VALUE) {
- if (cur_val == NULL)
- cur_val = pdkim_strnew(NULL);
-
- if ( (*p == '\r') || (*p == '\n') )
- goto NEXT_CHAR;
-
- if ( (*p == ';') || (*p == '\0') ) {
- if (cur_tag->len > 0) {
- pdkim_strtrim(cur_val);
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream, "%s=%s\n", cur_tag->str, cur_val->str);
- #endif
- switch (cur_tag->str[0]) {
- case 'v':
- /* This tag isn't evaluated because:
- - We only support version DKIM1.
- - Which is the default for this value (set below)
- - Other versions are currently not specified. */
- break;
- case 'h':
- pub->hashes = strdup(cur_val->str);
- break;
- case 'g':
- pub->granularity = strdup(cur_val->str);
- break;
- case 'n':
- pub->notes = pdkim_decode_qp(cur_val->str);
- break;
- case 'p':
- pub->key = pdkim_decode_base64(cur_val->str,&(pub->key_len));
- break;
- case 'k':
- pub->hashes = strdup(cur_val->str);
- break;
- case 's':
- pub->srvtype = strdup(cur_val->str);
- break;
- case 't':
- if (strchr(cur_val->str,'t') != NULL) pub->testing = 1;
- if (strchr(cur_val->str,'s') != NULL) pub->no_subdomaining = 1;
- break;
- default:
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream, "Unknown tag encountered\n");
- #endif
- break;
- }
- }
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
- where = PDKIM_HDR_LIMBO;
- goto NEXT_CHAR;
+ else
+ {
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM [%s] Body hash signature from headers: ", sig->domain);
+ pdkim_hexprint(sig->bodyhash.data, sig->bodyhash.len);
+ debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain);
+ }
+ sig->verify_status = PDKIM_VERIFY_FAIL;
+ sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY;
}
- else pdkim_strncat(cur_val,p,1);
- }
-
- NEXT_CHAR:
- if (*p == '\0') break;
- p++;
}
+}
- /* Set fallback defaults */
- if (pub->version == NULL) pub->version = strdup(PDKIM_PUB_RECORD_VERSION);
- if (pub->granularity == NULL) pub->granularity = strdup("*");
- if (pub->keytype == NULL) pub->keytype = strdup("rsa");
- if (pub->srvtype == NULL) pub->srvtype = strdup("*");
- /* p= is required */
- if (pub->key == NULL) {
- pdkim_free_pubkey(pub);
- return NULL;
- }
- return pub;
+static void
+pdkim_body_complete(pdkim_ctx * ctx)
+{
+pdkim_signature * sig;
+
+/* In simple body mode, if any empty lines were buffered,
+replace with one. rfc 4871 3.4.3 */
+/*XXX checking the signed-body-bytes is a gross hack; I think
+it indicates that all linebreaks should be buffered, including
+the one terminating a text line */
+
+for (sig = ctx->sig; sig; sig = sig->next)
+ if ( sig->canon_body == PDKIM_CANON_SIMPLE
+ && sig->signed_body_bytes == 0
+ && sig->num_buffered_blanklines > 0
+ )
+ (void) pdkim_update_sig_bodyhash(sig, &lineending, NULL);
+
+ctx->flags |= PDKIM_SEEN_EOD;
+ctx->linebuf_offset = 0;
}
+
/* -------------------------------------------------------------------------- */
-int pdkim_update_bodyhash(pdkim_ctx *ctx, char *data, int len) {
- pdkim_signature *sig = ctx->sig;
- /* Cache relaxed version of data */
- char *relaxed_data = NULL;
- int relaxed_len = 0;
-
- /* Traverse all signatures, updating their hashes. */
- while (sig != NULL) {
- /* Defaults to simple canon (no further treatment necessary) */
- char *canon_data = data;
- int canon_len = len;
-
- if (sig->canon_body == PDKIM_CANON_RELAXED) {
- /* Relax the line if not done already */
- if (relaxed_data == NULL) {
- int seen_wsp = 0;
- char *p = data;
- int q = 0;
- relaxed_data = malloc(len+1);
- if (relaxed_data == NULL) return PDKIM_ERR_OOM;
- while (*p != '\0') {
- char c = *p;
- if ( (c == '\t') || (c == ' ') ) {
- c = ' '; /* Turns WSP into SP */
- if (seen_wsp) {
- p++;
- continue;
- }
- else seen_wsp = 1;
- }
- else seen_wsp = 0;
- relaxed_data[q++] = c;
- p++;
- }
- relaxed_data[q] = '\0';
- relaxed_len = q;
+/* Call from pdkim_feed below for processing complete body lines */
+
+static void
+pdkim_bodyline_complete(pdkim_ctx * ctx)
+{
+blob line = {.data = ctx->linebuf, .len = ctx->linebuf_offset};
+pdkim_signature * sig;
+blob * rnl = NULL;
+blob * rline = NULL;
+
+/* Ignore extra data if we've seen the end-of-data marker */
+if (ctx->flags & PDKIM_SEEN_EOD) goto all_skip;
+
+/* We've always got one extra byte to stuff a zero ... */
+ctx->linebuf[line.len] = '\0';
+
+/* Terminate on EOD marker */
+if (ctx->flags & PDKIM_DOT_TERM)
+ {
+ if (memcmp(line.data, ".\r\n", 3) == 0)
+ { pdkim_body_complete(ctx); return; }
+
+ /* Unstuff dots */
+ if (memcmp(line.data, "..", 2) == 0)
+ { line.data++; line.len--; }
+ }
+
+/* Empty lines need to be buffered until we find a non-empty line */
+if (memcmp(line.data, "\r\n", 2) == 0)
+ {
+ for (sig = ctx->sig; sig; sig = sig->next) sig->num_buffered_blanklines++;
+ goto all_skip;
+ }
+
+/* Process line for each sig separately */
+for (sig = ctx->sig; sig; sig = sig->next)
+ {
+ if (sig->canon_body == PDKIM_CANON_RELAXED)
+ {
+ /* Lines with just spaces need to be buffered too */
+ uschar * cp = line.data;
+ char c;
+
+ while ((c = *cp))
+ {
+ if (c == '\r' && cp[1] == '\n') break;
+ if (c != ' ' && c != '\t') goto sig_process;
+ cp++;
}
- canon_data = relaxed_data;
- canon_len = relaxed_len;
+
+ sig->num_buffered_blanklines++;
+ goto sig_skip;
}
- /* Make sure we don't exceed the to-be-signed body length */
- if ((sig->bodylength >= 0) &&
- ((sig->signed_body_bytes+(unsigned long)canon_len) > sig->bodylength))
- canon_len = (sig->bodylength - sig->signed_body_bytes);
+sig_process:
+ /* At this point, we have a non-empty line, so release the buffered ones. */
- if (canon_len > 0) {
- if (sig->algo == PDKIM_ALGO_RSA_SHA1)
- sha1_update(sig->sha1_body,(unsigned char *)canon_data,canon_len);
- else
- sha2_update(sig->sha2_body,(unsigned char *)canon_data,canon_len);
- sig->signed_body_bytes += canon_len;
-#ifdef PDKIM_DEBUG
- if (ctx->debug_stream!=NULL)
- pdkim_quoteprint(ctx->debug_stream,canon_data,canon_len,0);
-#endif
+ while (sig->num_buffered_blanklines)
+ {
+ rnl = pdkim_update_sig_bodyhash(sig, &lineending, rnl);
+ sig->num_buffered_blanklines--;
}
- sig = sig->next;
+ rline = pdkim_update_sig_bodyhash(sig, &line, rline);
+sig_skip: ;
}
- if (relaxed_data != NULL) free(relaxed_data);
- return PDKIM_OK;
-};
+if (rnl) store_free(rnl);
+if (rline) store_free(rline);
+
+all_skip:
+
+ctx->linebuf_offset = 0;
+return;
+}
/* -------------------------------------------------------------------------- */
-int pdkim_finish_bodyhash(pdkim_ctx *ctx) {
- pdkim_signature *sig = ctx->sig;
+/* Callback from pdkim_feed below for processing complete headers */
+#define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:"
+
+static int
+pdkim_header_complete(pdkim_ctx * ctx)
+{
+pdkim_signature * sig, * last_sig;
+
+/* Special case: The last header can have an extra \r appended */
+if ( (ctx->cur_header->ptr > 1) &&
+ (ctx->cur_header->s[ctx->cur_header->ptr-1] == '\r') )
+ --ctx->cur_header->ptr;
+(void) string_from_gstring(ctx->cur_header);
- /* Traverse all signatures */
- while (sig != NULL) {
+if (++ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
+
+/* SIGNING -------------------------------------------------------------- */
+if (ctx->flags & PDKIM_MODE_SIGN)
+ for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */
+
+ /* Add header to the signed headers list (in reverse order) */
+ sig->headers = pdkim_prepend_stringlist(sig->headers, ctx->cur_header->s);
+
+/* VERIFICATION ----------------------------------------------------------- */
+/* DKIM-Signature: headers are added to the verification list */
+else
+ {
+#ifdef notdef
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM >> raw hdr: ");
+ pdkim_quoteprint(CUS ctx->cur_header->s, ctx->cur_header->ptr);
+ }
+#endif
+ if (strncasecmp(CCS ctx->cur_header->s,
+ DKIM_SIGNATURE_HEADERNAME,
+ Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0)
+ {
+ /* Create and chain new signature block. We could error-check for all
+ required tags here, but prefer to create the internal sig and expicitly
+ fail verification of it later. */
- /* Finish hashes */
- unsigned char bh[32]; /* SHA-256 = 32 Bytes, SHA-1 = 20 Bytes */
- if (sig->algo == PDKIM_ALGO_RSA_SHA1)
- sha1_finish(sig->sha1_body,bh);
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+
+ sig = pdkim_parse_sig_header(ctx, ctx->cur_header->s);
+
+ if (!(last_sig = ctx->sig))
+ ctx->sig = sig;
else
- sha2_finish(sig->sha2_body,bh);
-
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] Body bytes hashed: %lu\n",
- sig->domain, sig->signed_body_bytes);
- fprintf(ctx->debug_stream, "PDKIM [%s] bh computed: ", sig->domain);
- pdkim_hexprint(ctx->debug_stream, (char *)bh,
- (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32,1);
+ {
+ while (last_sig->next) last_sig = last_sig->next;
+ last_sig->next = sig;
+ }
}
- #endif
-
- /* SIGNING -------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- sig->bodyhash_len = (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32;
- sig->bodyhash = malloc(sig->bodyhash_len);
- if (sig->bodyhash == NULL) return PDKIM_ERR_OOM;
- memcpy(sig->bodyhash,bh,sig->bodyhash_len);
-
- /* If bodylength limit is set, and we have received less bytes
- than the requested amount, effectively remove the limit tag. */
- if (sig->signed_body_bytes < sig->bodylength) sig->bodylength = -1;
+
+ /* all headers are stored for signature verification */
+ ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header->s);
+ }
+
+BAIL:
+ctx->cur_header->s[ctx->cur_header->ptr = 0] = '\0'; /* leave buffer for reuse */
+return PDKIM_OK;
+}
+
+
+
+/* -------------------------------------------------------------------------- */
+#define HEADER_BUFFER_FRAG_SIZE 256
+
+DLLEXPORT int
+pdkim_feed(pdkim_ctx * ctx, uschar * data, int len)
+{
+int p, rc;
+
+/* Alternate EOD signal, used in non-dotstuffing mode */
+if (!data)
+ pdkim_body_complete(ctx);
+
+else for (p = 0; p<len; p++)
+ {
+ uschar c = data[p];
+
+ if (ctx->flags & PDKIM_PAST_HDRS)
+ {
+ if (c == '\n' && !(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */
+ {
+ ctx->linebuf[ctx->linebuf_offset++] = '\r';
+ if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1)
+ return PDKIM_ERR_LONG_LINE;
+ }
+
+ /* Processing body byte */
+ ctx->linebuf[ctx->linebuf_offset++] = c;
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
+ {
+ ctx->flags &= ~PDKIM_SEEN_CR;
+ pdkim_bodyline_complete(ctx);
+ }
+
+ if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1)
+ return PDKIM_ERR_LONG_LINE;
}
- /* VERIFICATION --------------------------------------------------------- */
- else {
- /* Compare bodyhash */
- if (memcmp(bh,sig->bodyhash,
- (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32) == 0) {
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream, "PDKIM [%s] Body hash verified OK\n",
- sig->domain);
- #endif
+ else
+ {
+ /* Processing header byte */
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
+ {
+ if (!(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */
+ ctx->cur_header = string_catn(ctx->cur_header, CUS "\r", 1);
+
+ if (ctx->flags & PDKIM_SEEN_LF) /* Seen last header line */
+ {
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
+
+ ctx->flags = (ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR)) | PDKIM_PAST_HDRS;
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ continue;
+ }
+ else
+ ctx->flags = (ctx->flags & ~PDKIM_SEEN_CR) | PDKIM_SEEN_LF;
}
- else {
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] Body hash did NOT verify\n",
- sig->domain);
- fprintf(ctx->debug_stream, "PDKIM [%s] bh signature: ", sig->domain);
- pdkim_hexprint(ctx->debug_stream, sig->bodyhash,
- (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32,1);
- }
- #endif
- sig->verify_status = PDKIM_VERIFY_FAIL;
- sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY;
+ else if (ctx->flags & PDKIM_SEEN_LF)
+ {
+ if (!(c == '\t' || c == ' ')) /* End of header */
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
+ ctx->flags &= ~PDKIM_SEEN_LF;
}
+
+ if (!ctx->cur_header || ctx->cur_header->ptr < PDKIM_MAX_HEADER_LEN)
+ ctx->cur_header = string_catn(ctx->cur_header, CUS &data[p], 1);
}
+ }
+return PDKIM_OK;
+}
- sig = sig->next;
+
+
+/* Extend a growing header with a continuation-linebreak */
+static gstring *
+pdkim_hdr_cont(gstring * str, int * col)
+{
+*col = 1;
+return string_catn(str, US"\r\n\t", 3);
+}
+
+
+
+/*
+ * RFC 5322 specifies that header line length SHOULD be no more than 78
+ * lets make it so!
+ * pdkim_headcat
+ *
+ * returns uschar * (not nul-terminated)
+ *
+ * col: this int holds and receives column number (octets since last '\n')
+ * str: partial string to append to
+ * pad: padding, split line or space after before or after eg: ";"
+ * intro: - must join to payload eg "h=", usually the tag name
+ * payload: eg base64 data - long data can be split arbitrarily.
+ *
+ * this code doesn't fold the header in some of the places that RFC4871
+ * allows: As per RFC5322(2.2.3) it only folds before or after tag-value
+ * pairs and inside long values. it also always spaces or breaks after the
+ * "pad"
+ *
+ * no guarantees are made for output given out-of range input. like tag
+ * names longer than 78, or bogus col. Input is assumed to be free of line breaks.
+ */
+
+static gstring *
+pdkim_headcat(int * col, gstring * str,
+ const uschar * pad, const uschar * intro, const uschar * payload)
+{
+size_t l;
+
+if (pad)
+ {
+ l = Ustrlen(pad);
+ if (*col + l > 78)
+ str = pdkim_hdr_cont(str, col);
+ str = string_catn(str, pad, l);
+ *col += l;
}
- return PDKIM_OK;
-};
+l = (pad?1:0) + (intro?Ustrlen(intro):0);
+if (*col + l > 78)
+ { /*can't fit intro - start a new line to make room.*/
+ str = pdkim_hdr_cont(str, col);
+ l = intro?Ustrlen(intro):0;
+ }
+l += payload ? Ustrlen(payload):0 ;
-/* -------------------------------------------------------------------------- */
-/* Callback from pdkim_feed below for processing complete body lines */
-int pdkim_bodyline_complete(pdkim_ctx *ctx) {
- char *p = ctx->linebuf;
- int n = ctx->linebuf_offset;
-
- /* Ignore extra data if we've seen the end-of-data marker */
- if (ctx->seen_eod) goto BAIL;
-
- /* We've always got one extra byte to stuff a zero ... */
- ctx->linebuf[(ctx->linebuf_offset)] = '\0';
-
- if (ctx->input_mode == PDKIM_INPUT_SMTP) {
- /* Terminate on EOD marker */
- if (memcmp(p,".\r\n",3) == 0) {
- ctx->seen_eod = 1;
- goto BAIL;
+while (l>77)
+ { /* this fragment will not fit on a single line */
+ if (pad)
+ {
+ str = string_catn(str, US" ", 1);
+ *col += 1;
+ pad = NULL; /* only want this once */
+ l--;
}
- /* Unstuff dots */
- if (memcmp(p,"..",2) == 0) {
- p++;
- n--;
+
+ if (intro)
+ {
+ size_t sl = Ustrlen(intro);
+
+ str = string_catn(str, intro, sl);
+ *col += sl;
+ l -= sl;
+ intro = NULL; /* only want this once */
+ }
+
+ if (payload)
+ {
+ size_t sl = Ustrlen(payload);
+ size_t chomp = *col+sl < 77 ? sl : 78-*col;
+
+ str = string_catn(str, payload, chomp);
+ *col += chomp;
+ payload += chomp;
+ l -= chomp-1;
}
+
+ /* the while precondition tells us it didn't fit. */
+ str = pdkim_hdr_cont(str, col);
}
- /* Empty lines need to be buffered until we find a non-empty line */
- if (memcmp(p,"\r\n",2) == 0) {
- ctx->num_buffered_crlf++;
- goto BAIL;
+if (*col + l > 78)
+ {
+ str = pdkim_hdr_cont(str, col);
+ pad = NULL;
}
- /* At this point, we have a non-empty line, so release the buffered ones. */
- while (ctx->num_buffered_crlf) {
- pdkim_update_bodyhash(ctx,"\r\n",2);
- ctx->num_buffered_crlf--;
+if (pad)
+ {
+ str = string_catn(str, US" ", 1);
+ *col += 1;
+ pad = NULL;
}
- pdkim_update_bodyhash(ctx,p,n);
+if (intro)
+ {
+ size_t sl = Ustrlen(intro);
- BAIL:
- ctx->linebuf_offset = 0;
- return PDKIM_OK;
+ str = string_catn(str, intro, sl);
+ *col += sl;
+ l -= sl;
+ intro = NULL;
+ }
+
+if (payload)
+ {
+ size_t sl = Ustrlen(payload);
+
+ str = string_catn(str, payload, sl);
+ *col += sl;
+ }
+
+return str;
}
/* -------------------------------------------------------------------------- */
-/* Callback from pdkim_feed below for processing complete headers */
-#define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:"
-int pdkim_header_complete(pdkim_ctx *ctx) {
- pdkim_signature *sig = ctx->sig;
-
- /* Special case: The last header can have an extra \r appended */
- if ( (ctx->cur_header->len > 1) &&
- (ctx->cur_header->str[(ctx->cur_header->len)-1] == '\r') ) {
- ctx->cur_header->str[(ctx->cur_header->len)-1] = '\0';
- ctx->cur_header->len--;
- }
- ctx->num_headers++;
- if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
+static uschar *
+pdkim_create_header(pdkim_signature * sig, BOOL final)
+{
+uschar * base64_bh;
+uschar * base64_b;
+int col = 0;
+gstring * hdr;
+gstring * canon_all;
- /* Traverse all signatures */
- while (sig != NULL) {
- pdkim_stringlist *list;
+canon_all = string_cat (NULL, pdkim_canons[sig->canon_headers]);
+canon_all = string_catn(canon_all, US"/", 1);
+canon_all = string_cat (canon_all, pdkim_canons[sig->canon_body]);
+(void) string_from_gstring(canon_all);
- /* SIGNING -------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- if (header_name_match(ctx->cur_header->str,
- sig->sign_headers?
- sig->sign_headers:
- PDKIM_DEFAULT_SIGN_HEADERS, 0) != PDKIM_OK) goto NEXT_SIG;
- }
- /* VERIFICATION --------------------------------------------------------- */
- else {
- /* Header is not included or all instances were already 'ticked off' */
- if (header_name_match(ctx->cur_header->str,
- sig->hnames_check, 1) != PDKIM_OK) goto NEXT_SIG;
+hdr = string_cat(NULL, US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION);
+col = hdr->ptr;
+
+/* Required and static bits */
+hdr = pdkim_headcat(&col, hdr, US";", US"a=", dkim_sig_to_a_tag(sig));
+hdr = pdkim_headcat(&col, hdr, US";", US"q=", pdkim_querymethods[sig->querymethod]);
+hdr = pdkim_headcat(&col, hdr, US";", US"c=", canon_all->s);
+hdr = pdkim_headcat(&col, hdr, US";", US"d=", sig->domain);
+hdr = pdkim_headcat(&col, hdr, US";", US"s=", sig->selector);
+
+/* list of header names can be split between items. */
+ {
+ uschar * n = string_copy(sig->headernames);
+ uschar * i = US"h=";
+ uschar * s = US";";
+
+ while (*n)
+ {
+ uschar * c = Ustrchr(n, ':');
+
+ if (c) *c ='\0';
+
+ if (!i)
+ hdr = pdkim_headcat(&col, hdr, NULL, NULL, US":");
+
+ hdr = pdkim_headcat(&col, hdr, s, i, n);
+
+ if (!c)
+ break;
+
+ n = c+1;
+ s = NULL;
+ i = NULL;
}
+ }
- /* Add header to the signed headers list (in reverse order) */
- list = pdkim_prepend_stringlist(sig->headers,
- ctx->cur_header->str);
- if (list == NULL) return PDKIM_ERR_OOM;
- sig->headers = list;
+base64_bh = pdkim_encode_base64(&sig->bodyhash);
+hdr = pdkim_headcat(&col, hdr, US";", US"bh=", base64_bh);
+
+/* Optional bits */
+if (sig->identity)
+ hdr = pdkim_headcat(&col, hdr, US";", US"i=", sig->identity);
+
+if (sig->created > 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created);
+ hdr = pdkim_headcat(&col, hdr, US";", US"t=", minibuf);
+}
- NEXT_SIG:
- sig = sig->next;
+if (sig->expires > 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires);
+ hdr = pdkim_headcat(&col, hdr, US";", US"x=", minibuf);
}
- /* DKIM-Signature: headers are added to the verification list */
- if ( (ctx->mode == PDKIM_MODE_VERIFY) &&
- (strncasecmp(ctx->cur_header->str,
- DKIM_SIGNATURE_HEADERNAME,
- strlen(DKIM_SIGNATURE_HEADERNAME)) == 0) ) {
- pdkim_signature *new_sig;
- /* Create and chain new signature block */
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream,
- "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- #endif
- new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header->str);
- if (new_sig != NULL) {
- pdkim_signature *last_sig = ctx->sig;
- if (last_sig == NULL) {
- ctx->sig = new_sig;
- }
- else {
- while (last_sig->next != NULL) { last_sig = last_sig->next; };
- last_sig->next = new_sig;
- }
- }
- else {
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,"Error while parsing signature header\n");
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- }
- #endif
- }
+if (sig->bodylength >= 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength);
+ hdr = pdkim_headcat(&col, hdr, US";", US"l=", minibuf);
}
- BAIL:
- pdkim_strclear(ctx->cur_header); /* Re-use existing pdkim_str */
- return PDKIM_OK;
-};
+/* Preliminary or final version? */
+if (final)
+ {
+ base64_b = pdkim_encode_base64(&sig->sighash);
+ hdr = pdkim_headcat(&col, hdr, US";", US"b=", base64_b);
+ /* add trailing semicolon: I'm not sure if this is actually needed */
+ hdr = pdkim_headcat(&col, hdr, NULL, US";", US"");
+ }
+else
+ {
+ /* To satisfy the rule "all surrounding whitespace [...] deleted"
+ ( RFC 6376 section 3.7 ) we ensure there is no whitespace here. Otherwise
+ the headcat routine could insert a linebreak which the relaxer would reduce
+ to a single space preceding the terminating semicolon, resulting in an
+ incorrect header-hash. */
+ hdr = pdkim_headcat(&col, hdr, US";", US"b=;", US"");
+ }
+
+return string_from_gstring(hdr);
+}
/* -------------------------------------------------------------------------- */
-#define HEADER_BUFFER_FRAG_SIZE 256
-DLLEXPORT int pdkim_feed (pdkim_ctx *ctx,
- char *data,
- int len) {
- int p;
- for (p=0;p<len;p++) {
- char c = data[p];
- if (ctx->past_headers) {
- /* Processing body byte */
- ctx->linebuf[(ctx->linebuf_offset)++] = c;
- if (c == '\n') {
- int rc = pdkim_bodyline_complete(ctx); /* End of line */
- if (rc != PDKIM_OK) return rc;
- }
- if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1))
- return PDKIM_ERR_LONG_LINE;
- }
- else {
- /* Processing header byte */
- if (c != '\r') {
- if (c == '\n') {
- if (ctx->seen_lf) {
- int rc = pdkim_header_complete(ctx); /* Seen last header line */
- if (rc != PDKIM_OK) return rc;
- ctx->past_headers = 1;
- ctx->seen_lf = 0;
-#ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream,
- "PDKIM >> Hashed body data, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
-#endif
- continue;
- }
- else ctx->seen_lf = 1;
- }
- else if (ctx->seen_lf) {
- if (! ((c == '\t') || (c == ' '))) {
- int rc = pdkim_header_complete(ctx); /* End of header */
- if (rc != PDKIM_OK) return rc;
- }
- ctx->seen_lf = 0;
- }
- }
- if (ctx->cur_header == NULL) {
- ctx->cur_header = pdkim_strnew(NULL);
- if (ctx->cur_header == NULL) return PDKIM_ERR_OOM;
- }
- if (ctx->cur_header->len < PDKIM_MAX_HEADER_LEN)
- if (pdkim_strncat(ctx->cur_header,&data[p],1) == NULL)
- return PDKIM_ERR_OOM;
- }
+
+static pdkim_pubkey *
+pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx,
+ const uschar ** errstr)
+{
+uschar * dns_txt_name, * dns_txt_reply;
+pdkim_pubkey * p;
+
+/* Fetch public key for signing domain, from DNS */
+
+dns_txt_name = string_sprintf("%s._domainkey.%s.", sig->selector, sig->domain);
+
+dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN);
+memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN);
+
+if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK
+ || dns_txt_reply[0] == '\0'
+ )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE;
+ return NULL;
}
- return PDKIM_OK;
-};
+DEBUG(D_acl)
+ {
+ debug_printf(
+ "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"
+ " %s\n"
+ " Raw record: ",
+ dns_txt_name);
+ pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply));
+ }
-/* -------------------------------------------------------------------------- */
-char *pdkim_create_header(pdkim_signature *sig, int final) {
- char *rc = NULL;
- char *base64_bh = NULL;
- char *base64_b = NULL;
- pdkim_str *hdr = pdkim_strnew("DKIM-Signature: v="PDKIM_SIGNATURE_VERSION);
- if (hdr == NULL) return NULL;
-
- base64_bh = pdkim_encode_base64(sig->bodyhash, sig->bodyhash_len);
- if (base64_bh == NULL) goto BAIL;
-
- /* Required and static bits */
- if (
- pdkim_strcat(hdr,"; a=") &&
- pdkim_strcat(hdr,pdkim_algos[sig->algo]) &&
- pdkim_strcat(hdr,"; q=") &&
- pdkim_strcat(hdr,pdkim_querymethods[sig->querymethod]) &&
- pdkim_strcat(hdr,"; c=") &&
- pdkim_strcat(hdr,pdkim_canons[sig->canon_headers]) &&
- pdkim_strcat(hdr,"/") &&
- pdkim_strcat(hdr,pdkim_canons[sig->canon_body]) &&
- pdkim_strcat(hdr,"; d=") &&
- pdkim_strcat(hdr,sig->domain) &&
- pdkim_strcat(hdr,"; s=") &&
- pdkim_strcat(hdr,sig->selector) &&
- pdkim_strcat(hdr,";\r\n\th=") &&
- pdkim_strcat(hdr,sig->headernames) &&
- pdkim_strcat(hdr,"; bh=") &&
- pdkim_strcat(hdr,base64_bh) &&
- pdkim_strcat(hdr,";\r\n\t")
- ) {
- /* Optional bits */
- if (sig->identity != NULL) {
- if (!( pdkim_strcat(hdr,"i=") &&
- pdkim_strcat(hdr,sig->identity) &&
- pdkim_strcat(hdr,";") ) ) {
- goto BAIL;
- }
- }
- if (sig->created > 0) {
- if (!( pdkim_strcat(hdr,"t=") &&
- pdkim_numcat(hdr,sig->created) &&
- pdkim_strcat(hdr,";") ) ) {
- goto BAIL;
- }
- }
- if (sig->expires > 0) {
- if (!( pdkim_strcat(hdr,"x=") &&
- pdkim_numcat(hdr,sig->expires) &&
- pdkim_strcat(hdr,";") ) ) {
- goto BAIL;
- }
- }
- if (sig->bodylength >= 0) {
- if (!( pdkim_strcat(hdr,"l=") &&
- pdkim_numcat(hdr,sig->bodylength) &&
- pdkim_strcat(hdr,";") ) ) {
- goto BAIL;
- }
- }
- /* Extra linebreak */
- if (hdr->str[(hdr->len)-1] == ';') {
- if (!pdkim_strcat(hdr," \r\n\t")) goto BAIL;
- }
- /* Preliminary or final version? */
- if (final) {
- base64_b = pdkim_encode_base64(sig->sigdata, sig->sigdata_len);
- if (base64_b == NULL) goto BAIL;
- if (
- pdkim_strcat(hdr,"b=") &&
- pdkim_strcat(hdr,base64_b) &&
- pdkim_strcat(hdr,";")
- ) goto DONE;
- }
- else {
- if (pdkim_strcat(hdr,"b=;")) goto DONE;
+if ( !(p = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply))
+ || (Ustrcmp(p->srvtype, "*") != 0 && Ustrcmp(p->srvtype, "email") != 0)
+ )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD;
+
+ DEBUG(D_acl)
+ {
+ if (p)
+ debug_printf(" Invalid public key service type '%s'\n", p->srvtype);
+ else
+ debug_printf(" Error while parsing public key record\n");
+ debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
-
- goto BAIL;
+ return NULL;
}
- DONE:
- rc = strdup(hdr->str);
+DEBUG(D_acl) debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- BAIL:
- pdkim_strfree(hdr);
- if (base64_bh != NULL) free(base64_bh);
- if (base64_b != NULL) free(base64_b);
- return rc;
+/* Import public key */
+if ((*errstr = exim_dkim_verify_init(&p->key, vctx)))
+ {
+ DEBUG(D_acl) debug_printf("verify_init: %s\n", *errstr);
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT;
+ return NULL;
+ }
+
+return p;
}
/* -------------------------------------------------------------------------- */
-DLLEXPORT int pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) {
- pdkim_signature *sig = ctx->sig;
- pdkim_str *headernames = NULL; /* Collected signed header names */
-
- /* Check if we must still flush a (partial) header. If that is the
- case, the message has no body, and we must compute a body hash
- out of '<CR><LF>' */
- if (ctx->cur_header->len) {
- int rc = pdkim_header_complete(ctx);
- if (rc != PDKIM_OK) return rc;
- pdkim_update_bodyhash(ctx,"\r\n",2);
+
+DLLEXPORT int
+pdkim_feed_finish(pdkim_ctx * ctx, pdkim_signature ** return_signatures,
+ const uschar ** err)
+{
+pdkim_signature * sig;
+
+/* Check if we must still flush a (partial) header. If that is the
+ case, the message has no body, and we must compute a body hash
+ out of '<CR><LF>' */
+if (ctx->cur_header && ctx->cur_header->ptr > 0)
+ {
+ blob * rnl = NULL;
+ int rc;
+
+ if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK)
+ return rc;
+
+ for (sig = ctx->sig; sig; sig = sig->next)
+ rnl = pdkim_update_sig_bodyhash(sig, &lineending, rnl);
+ if (rnl) store_free(rnl);
}
- else {
- /* For non-smtp input, check if there's an unfinished line in the
- body line buffer. If that is the case, we must add a CRLF to the
- hash to properly terminate the message. */
- if ((ctx->input_mode == PDKIM_INPUT_NORMAL) && ctx->linebuf_offset) {
- pdkim_update_bodyhash(ctx, ctx->linebuf, ctx->linebuf_offset);
- pdkim_update_bodyhash(ctx,"\r\n",2);
+else
+ DEBUG(D_acl) debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+
+/* Build (and/or evaluate) body hash */
+pdkim_finish_bodyhash(ctx);
+
+for (sig = ctx->sig; sig; sig = sig->next)
+ {
+ hctx hhash_ctx;
+ uschar * sig_hdr = US"";
+ blob hhash;
+ gstring * hdata = NULL;
+
+ if (!exim_sha_init(&hhash_ctx, pdkim_hashes[sig->hashtype].exim_hashmethod))
+ {
+ DEBUG(D_acl)
+ debug_printf("PDKIM: hash setup error, possibly nonhandled hashtype\n");
+ break;
}
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream,
- "\nPDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- #endif
- }
- /* Build (and/or evaluate) body hash */
- if (pdkim_finish_bodyhash(ctx) != PDKIM_OK) return PDKIM_ERR_OOM;
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Headers to be signed: >>>>>>>>>>>>\n"
+ " %s\n",
+ sig->sign_headers);
- /* SIGNING -------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- headernames = pdkim_strnew(NULL);
- if (headernames == NULL) return PDKIM_ERR_OOM;
- }
- /* ---------------------------------------------------------------------- */
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>\n");
- while (sig != NULL) {
- sha1_context sha1_headers;
- sha2_context sha2_headers;
- char *sig_hdr;
- char headerhash[32];
- if (sig->algo == PDKIM_ALGO_RSA_SHA1)
- sha1_starts(&sha1_headers);
- else
- sha2_starts(&sha2_headers,0);
-
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream,
- "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n");
- #endif
-
- /* SIGNING ---------------------------------------------------------------- */
- /* When signing, walk through our header list and add them to the hash. As we
- go, construct a list of the header's names to use for the h= parameter. */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- pdkim_stringlist *p = sig->headers;
- while (p != NULL) {
- char *rh = NULL;
- /* Collect header names (Note: colon presence is guaranteed here) */
- char *q = strchr(p->value,':');
- if (pdkim_strncat(headernames, p->value,
- (q-(p->value))+((p->next==NULL)?0:1)) == NULL)
- return PDKIM_ERR_OOM;
-
- if (sig->canon_headers == PDKIM_CANON_RELAXED)
- rh = pdkim_relax_header(p->value,1); /* cook header for relaxed canon */
- else
- rh = strdup(p->value); /* just copy it for simple canon */
-
- if (rh == NULL) return PDKIM_ERR_OOM;
-
- /* Feed header to the hash algorithm */
- if (sig->algo == PDKIM_ALGO_RSA_SHA1)
- sha1_update(&(sha1_headers),(unsigned char *)rh,strlen(rh));
- else
- sha2_update(&(sha2_headers),(unsigned char *)rh,strlen(rh));
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- pdkim_quoteprint(ctx->debug_stream, rh, strlen(rh), 1);
- #endif
- free(rh);
- p = p->next;
+ /* SIGNING ---------------------------------------------------------------- */
+ /* When signing, walk through our header list and add them to the hash. As we
+ go, construct a list of the header's names to use for the h= parameter.
+ Then append to that list any remaining header names for which there was no
+ header to sign. */
+
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ {
+ gstring * g = NULL;
+ pdkim_stringlist *p;
+ const uschar * l;
+ uschar * s;
+ int sep = 0;
+
+ sig->headernames = NULL; /* Collected signed header names */
+
+ for (p = sig->headers; p; p = p->next)
+ {
+ uschar * rh = p->value;
+
+ if (header_name_match(rh, sig->sign_headers) == PDKIM_OK)
+ {
+ /* Collect header names (Note: colon presence is guaranteed here) */
+ g = string_append_listele_n(g, ':', rh, Ustrchr(rh, ':') - rh);
+
+ if (sig->canon_headers == PDKIM_CANON_RELAXED)
+ rh = pdkim_relax_header(rh, TRUE); /* cook header for relaxed canon */
+
+ /* Feed header to the hash algorithm */
+ exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
+
+ /* Remember headers block for signing (when the library cannot do incremental) */
+ hdata = exim_dkim_data_append(hdata, rh);
+
+ DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
+ }
}
+
+ /* Any headers we wanted to sign but were not present must also be listed */
+ l = sig->sign_headers;
+ while((s = string_nextinlist(&l, &sep, NULL, 0)))
+ if (*s != '_')
+ g = string_append_listele(g, ':', s);
+ sig->headernames = string_from_gstring(g);
+
+ /* Create signature header with b= omitted */
+ sig_hdr = pdkim_create_header(sig, FALSE);
}
- /* VERIFICATION ----------------------------------------------------------- */
- /* When verifying, walk through the header name list in the h= parameter and
- add the headers to the hash in that order. */
- else {
- char *b = strdup(sig->headernames);
- char *p = b;
- char *q = NULL;
- if (b == NULL) return PDKIM_ERR_OOM;
-
- while(1) {
- pdkim_stringlist *hdrs = sig->headers;
- q = strchr(p,':');
- if (q != NULL) *q = '\0';
- while (hdrs != NULL) {
- if ( (strncasecmp(hdrs->value,p,strlen(p)) == 0) &&
- ((hdrs->value)[strlen(p)] == ':') ) {
- char *rh = NULL;
- if (sig->canon_headers == PDKIM_CANON_RELAXED)
- rh = pdkim_relax_header(hdrs->value,1); /* cook header for relaxed canon */
- else
- rh = strdup(hdrs->value); /* just copy it for simple canon */
- if (rh == NULL) return PDKIM_ERR_OOM;
- /* Feed header to the hash algorithm */
- if (sig->algo == PDKIM_ALGO_RSA_SHA1)
- sha1_update(&(sha1_headers),(unsigned char *)rh,strlen(rh));
- else
- sha2_update(&(sha2_headers),(unsigned char *)rh,strlen(rh));
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- pdkim_quoteprint(ctx->debug_stream, rh, strlen(rh), 1);
- #endif
- free(rh);
- (hdrs->value)[0] = '_';
- break;
- }
- hdrs = hdrs->next;
- }
- if (q == NULL) break;
- p = q+1;
+
+ /* VERIFICATION ----------------------------------------------------------- */
+ /* When verifying, walk through the header name list in the h= parameter and
+ add the headers to the hash in that order. */
+ else
+ {
+ uschar * p = sig->headernames;
+ uschar * q;
+ pdkim_stringlist * hdrs;
+
+ if (p)
+ {
+ /* clear tags */
+ for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
+ hdrs->tag = 0;
+
+ p = string_copy(p);
+ while(1)
+ {
+ if ((q = Ustrchr(p, ':')))
+ *q = '\0';
+
+ /*XXX walk the list of headers in same order as received. */
+ for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
+ if ( hdrs->tag == 0
+ && strncasecmp(CCS hdrs->value, CCS p, Ustrlen(p)) == 0
+ && (hdrs->value)[Ustrlen(p)] == ':'
+ )
+ {
+ /* cook header for relaxed canon, or just copy it for simple */
+
+ uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED
+ ? pdkim_relax_header(hdrs->value, TRUE)
+ : string_copy(CUS hdrs->value);
+
+ /* Feed header to the hash algorithm */
+ exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
+
+ DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
+ hdrs->tag = 1;
+ break;
+ }
+
+ if (!q) break;
+ p = q+1;
+ }
+
+ sig_hdr = string_copy(sig->rawsig_no_b_val);
}
- free(b);
}
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream)
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- #endif
-
- /* SIGNING ---------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- /* Copy headernames to signature struct */
- sig->headernames = strdup(headernames->str);
- pdkim_strfree(headernames);
+ DEBUG(D_acl) debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- /* Create signature header with b= omitted */
- sig_hdr = pdkim_create_header(ctx->sig,0);
+ DEBUG(D_acl)
+ {
+ debug_printf(
+ "PDKIM >> Signed DKIM-Signature header, pre-canonicalized >>>>>>>>>>>>>\n");
+ pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr));
+ debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- /* VERIFICATION ----------------------------------------------------------- */
- else {
- sig_hdr = strdup(sig->rawsig_no_b_val);
+
+ /* Relax header if necessary */
+ if (sig->canon_headers == PDKIM_CANON_RELAXED)
+ sig_hdr = pdkim_relax_header(sig_hdr, FALSE);
+
+ DEBUG(D_acl)
+ {
+ debug_printf(
+ "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n");
+ pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr));
+ debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- /* ------------------------------------------------------------------------ */
- if (sig_hdr == NULL) return PDKIM_ERR_OOM;
+ /* Finalize header hash */
+ exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr));
+ exim_sha_finish(&hhash_ctx, &hhash);
- /* Relax header if necessary */
- if (sig->canon_headers == PDKIM_CANON_RELAXED) {
- char *relaxed_hdr = pdkim_relax_header(sig_hdr,0);
- free(sig_hdr);
- if (relaxed_hdr == NULL) return PDKIM_ERR_OOM;
- sig_hdr = relaxed_hdr;
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM [%s] Header %s computed: ",
+ sig->domain, pdkim_hashes[sig->hashtype].dkim_hashname);
+ pdkim_hexprint(hhash.data, hhash.len);
}
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,
- "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n");
- pdkim_quoteprint(ctx->debug_stream, sig_hdr, strlen(sig_hdr), 1);
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- }
- #endif
-
- /* Finalize header hash */
- if (sig->algo == PDKIM_ALGO_RSA_SHA1) {
- sha1_update(&(sha1_headers),(unsigned char *)sig_hdr,strlen(sig_hdr));
- sha1_finish(&(sha1_headers),(unsigned char *)headerhash);
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] hh computed: ", sig->domain);
- pdkim_hexprint(ctx->debug_stream, headerhash, 20, 1);
- }
- #endif
- }
- else {
- sha2_update(&(sha2_headers),(unsigned char *)sig_hdr,strlen(sig_hdr));
- sha2_finish(&(sha2_headers),(unsigned char *)headerhash);
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] hh computed: ", sig->domain);
- pdkim_hexprint(ctx->debug_stream, headerhash, 32, 1);
+ /* Remember headers block for signing (when the signing library cannot do
+ incremental) */
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ hdata = exim_dkim_data_append(hdata, US sig_hdr);
+
+ /* SIGNING ---------------------------------------------------------------- */
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ {
+ es_ctx sctx;
+
+ /* Import private key, including the keytype */
+/*XXX extend for non-RSA algos */
+ if ((*err = exim_dkim_signing_init(US sig->privkey, &sctx)))
+ {
+ DEBUG(D_acl) debug_printf("signing_init: %s\n", *err);
+ return PDKIM_ERR_RSA_PRIVKEY;
}
- #endif
- }
-
- free(sig_hdr);
- /* SIGNING ---------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN) {
- rsa_context rsa;
+ /* Do signing. With OpenSSL we are signing the hash of headers just
+ calculated, with GnuTLS we have to sign an entire block of headers
+ (due to available interfaces) and it recalculates the hash internally. */
- rsa_init(&rsa,RSA_PKCS_V15,0,NULL,NULL);
+#if defined(SIGN_GNUTLS)
+ hhash.data = hdata->s;
+ hhash.len = hdata->ptr;
+#endif
- /* Perform private key operation */
- if (rsa_parse_key(&rsa, (unsigned char *)sig->rsa_privkey,
- strlen(sig->rsa_privkey), NULL, 0) != 0) {
- return PDKIM_ERR_RSA_PRIVKEY;
+/*XXX extend for non-RSA algos */
+ if ((*err = exim_dkim_sign(&sctx,
+ pdkim_hashes[sig->hashtype].exim_hashmethod,
+ &hhash, &sig->sighash)))
+ {
+ DEBUG(D_acl) debug_printf("signing: %s\n", *err);
+ return PDKIM_ERR_RSA_SIGNING;
}
- sig->sigdata_len = mpi_size(&(rsa.N));
- sig->sigdata = malloc(sig->sigdata_len);
- if (sig->sigdata == NULL) return PDKIM_ERR_OOM;
-
- if (rsa_pkcs1_sign( &rsa, RSA_PRIVATE,
- ((sig->algo == PDKIM_ALGO_RSA_SHA1)?
- RSA_SHA1:RSA_SHA256),
- 0,
- (unsigned char *)headerhash,
- (unsigned char *)sig->sigdata ) != 0) {
- return PDKIM_ERR_RSA_SIGNING;
+ DEBUG(D_acl)
+ {
+ debug_printf( "PDKIM [%s] b computed: ", sig->domain);
+ pdkim_hexprint(sig->sighash.data, sig->sighash.len);
}
- rsa_free(&rsa);
+ sig->signature_header = pdkim_create_header(sig, TRUE);
+ }
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] b computed: ",
- sig->domain);
- pdkim_hexprint(ctx->debug_stream, sig->sigdata, sig->sigdata_len, 1);
+ /* VERIFICATION ----------------------------------------------------------- */
+ else
+ {
+ ev_ctx vctx;
+
+ /* Make sure we have all required signature tags */
+ if (!( sig->domain && *sig->domain
+ && sig->selector && *sig->selector
+ && sig->headernames && *sig->headernames
+ && sig->bodyhash.data
+ && sig->sighash.data
+ && sig->keytype >= 0
+ && sig->hashtype >= 0
+ && sig->version
+ ) )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR;
+
+ DEBUG(D_acl) debug_printf(
+ " Error in DKIM-Signature header: tags missing or invalid\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ goto NEXT_VERIFY;
}
- #endif
- sig->signature_header = pdkim_create_header(ctx->sig,1);
- if (sig->signature_header == NULL) return PDKIM_ERR_OOM;
- }
- /* VERIFICATION ----------------------------------------------------------- */
- else {
- rsa_context rsa;
- char *dns_txt_name, *dns_txt_reply;
-
- rsa_init(&rsa,RSA_PKCS_V15,0,NULL,NULL);
-
- dns_txt_name = malloc(PDKIM_DNS_TXT_MAX_NAMELEN);
- if (dns_txt_name == NULL) return PDKIM_ERR_OOM;
- dns_txt_reply = malloc(PDKIM_DNS_TXT_MAX_RECLEN);
- if (dns_txt_reply == NULL) {
- free(dns_txt_name);
- return PDKIM_ERR_OOM;
- }
- memset(dns_txt_reply,0,PDKIM_DNS_TXT_MAX_RECLEN);
- memset(dns_txt_name ,0,PDKIM_DNS_TXT_MAX_NAMELEN);
-
- if (snprintf(dns_txt_name,PDKIM_DNS_TXT_MAX_NAMELEN,
- "%s._domainkey.%s.",
- sig->selector,sig->domain) >= PDKIM_DNS_TXT_MAX_NAMELEN) {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_BUFFER_SIZE;
- goto NEXT_VERIFY;
- };
-
- if ((ctx->dns_txt_callback(dns_txt_name, dns_txt_reply) != PDKIM_OK) ||
- (dns_txt_reply[0] == '\0')) {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE;
- goto NEXT_VERIFY;
- }
+ /* Make sure sig uses supported DKIM version (only v1) */
+ if (sig->version != 1)
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION;
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,
- "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- fprintf(ctx->debug_stream,"Raw record: ");
- pdkim_quoteprint(ctx->debug_stream, dns_txt_reply, strlen(dns_txt_reply), 1);
- }
- #endif
-
- sig->pubkey = pdkim_parse_pubkey_record(ctx,dns_txt_reply);
- if (sig->pubkey == NULL) {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING;
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,"Error while parsing public key record\n");
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- }
- #endif
- goto NEXT_VERIFY;
+ DEBUG(D_acl) debug_printf(
+ " Error in DKIM-Signature header: unsupported DKIM version\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ goto NEXT_VERIFY;
}
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream,
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ DEBUG(D_acl)
+ {
+ debug_printf( "PDKIM [%s] b from mail: ", sig->domain);
+ pdkim_hexprint(sig->sighash.data, sig->sighash.len);
}
- #endif
-
- if (rsa_parse_public_key(&rsa,
- (unsigned char *)sig->pubkey->key,
- sig->pubkey->key_len) != 0) {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING;
- goto NEXT_VERIFY;
+
+ if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err)))
+ goto NEXT_VERIFY;
+
+ /* If the pubkey limits to a list of specific hashes, ignore sigs that
+ do not have the hash part of the sig algorithm matching */
+
+ if (sig->pubkey->hashes)
+ {
+ const uschar * list = sig->pubkey->hashes, * ele;
+ int sep = ':';
+ while ((ele = string_nextinlist(&list, &sep, NULL, 0)))
+ if (Ustrcmp(ele, pdkim_hashes[sig->hashtype].dkim_hashname) == 0) break;
+ if (!ele)
+ {
+ DEBUG(D_acl) debug_printf("pubkey h=%s vs. sig a=%s_%s\n",
+ sig->pubkey->hashes,
+ pdkim_keytypes[sig->keytype],
+ pdkim_hashes[sig->hashtype].dkim_hashname);
+ sig->verify_status = PDKIM_VERIFY_FAIL;
+ sig->verify_ext_status = PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH;
+ goto NEXT_VERIFY;
+ }
}
- /* Check the signature */
- if (rsa_pkcs1_verify(&rsa,
- RSA_PUBLIC,
- ((sig->algo == PDKIM_ALGO_RSA_SHA1)?
- RSA_SHA1:RSA_SHA256),
- 0,
- (unsigned char *)headerhash,
- (unsigned char *)sig->sigdata) != 0) {
- sig->verify_status = PDKIM_VERIFY_FAIL;
- sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE;
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] signature did NOT verify OK\n",
- sig->domain);
- }
- #endif
- goto NEXT_VERIFY;
+ /* Check the signature */
+/*XXX needs extension for non-RSA */
+ if ((*err = exim_dkim_verify(&vctx,
+ pdkim_hashes[sig->hashtype].exim_hashmethod,
+ &hhash, &sig->sighash)))
+ {
+ DEBUG(D_acl) debug_printf("headers verify: %s\n", *err);
+ sig->verify_status = PDKIM_VERIFY_FAIL;
+ sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE;
+ goto NEXT_VERIFY;
}
- /* We have a winner! */
+
+ /* We have a winner! (if bodyhash was correct earlier) */
+ if (sig->verify_status == PDKIM_VERIFY_NONE)
sig->verify_status = PDKIM_VERIFY_PASS;
- #ifdef PDKIM_DEBUG
- if (ctx->debug_stream) {
- fprintf(ctx->debug_stream, "PDKIM [%s] signature verified OK\n",
- sig->domain);
- }
- #endif
+NEXT_VERIFY:
- NEXT_VERIFY:
- rsa_free(&rsa);
- free(dns_txt_name);
- free(dns_txt_reply);
+ DEBUG(D_acl)
+ {
+ debug_printf("PDKIM [%s] signature status: %s",
+ sig->domain, pdkim_verify_status_str(sig->verify_status));
+ if (sig->verify_ext_status > 0)
+ debug_printf(" (%s)\n",
+ pdkim_verify_ext_status_str(sig->verify_ext_status));
+ else
+ debug_printf("\n");
+ }
}
-
- sig = sig->next;
}
- /* If requested, set return pointer to signature(s) */
- if (return_signatures != NULL) {
- *return_signatures = ctx->sig;
- }
+/* If requested, set return pointer to signature(s) */
+if (return_signatures)
+ *return_signatures = ctx->sig;
- return PDKIM_OK;
+return PDKIM_OK;
}
/* -------------------------------------------------------------------------- */
-DLLEXPORT pdkim_ctx *pdkim_init_verify(int input_mode,
- int(*dns_txt_callback)(char *, char *)
- ) {
- pdkim_ctx *ctx = malloc(sizeof(pdkim_ctx));
- if (ctx == NULL) return NULL;
- memset(ctx,0,sizeof(pdkim_ctx));
-
- ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN);
- if (ctx->linebuf == NULL) {
- free(ctx);
- return NULL;
- }
- ctx->mode = PDKIM_MODE_VERIFY;
- ctx->input_mode = input_mode;
- ctx->dns_txt_callback = dns_txt_callback;
+DLLEXPORT pdkim_ctx *
+pdkim_init_verify(int(*dns_txt_callback)(char *, char *), BOOL dot_stuffing)
+{
+pdkim_ctx * ctx;
+
+ctx = store_get(sizeof(pdkim_ctx));
+memset(ctx, 0, sizeof(pdkim_ctx));
+
+if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM;
+ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN);
+ctx->dns_txt_callback = dns_txt_callback;
- return ctx;
+return ctx;
}
/* -------------------------------------------------------------------------- */
-DLLEXPORT pdkim_ctx *pdkim_init_sign(int input_mode,
- char *domain,
- char *selector,
- char *rsa_privkey) {
- pdkim_ctx *ctx;
- pdkim_signature *sig;
-
- if (!domain || !selector || !rsa_privkey) return NULL;
-
- ctx = malloc(sizeof(pdkim_ctx));
- if (ctx == NULL) return NULL;
- memset(ctx,0,sizeof(pdkim_ctx));
-
- ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN);
- if (ctx->linebuf == NULL) {
- free(ctx);
- return NULL;
- }
- sig = malloc(sizeof(pdkim_signature));
- if (sig == NULL) {
- free(ctx->linebuf);
- free(ctx);
- return NULL;
- }
- memset(sig,0,sizeof(pdkim_signature));
- sig->bodylength = -1;
+/*XXX ? needs extension to cover non-RSA algo? */
+
+DLLEXPORT pdkim_signature *
+pdkim_init_sign(pdkim_ctx * ctx,
+ uschar * domain, uschar * selector, uschar * privkey,
+ uschar * hashname, const uschar ** errstr)
+{
+int hashtype;
+pdkim_signature * sig;
+
+if (!domain || !selector || !privkey)
+ return NULL;
+
+/* Allocate & init one signature struct */
- ctx->mode = PDKIM_MODE_SIGN;
- ctx->input_mode = input_mode;
- ctx->sig = sig;
+sig = store_get(sizeof(pdkim_signature));
+memset(sig, 0, sizeof(pdkim_signature));
- ctx->sig->domain = strdup(domain);
- ctx->sig->selector = strdup(selector);
- ctx->sig->rsa_privkey = strdup(rsa_privkey);
+sig->bodylength = -1;
- if (!ctx->sig->domain || !ctx->sig->selector || !ctx->sig->rsa_privkey) {
- pdkim_free_ctx(ctx);
- return NULL;
+sig->domain = string_copy(US domain);
+sig->selector = string_copy(US selector);
+sig->privkey = string_copy(US privkey);
+/*XXX no keytype yet; comes from privkey */
+
+for (hashtype = 0; hashtype < nelem(pdkim_hashes); hashtype++)
+ if (Ustrcmp(hashname, pdkim_hashes[hashtype].dkim_hashname) == 0)
+ { sig->hashtype = hashtype; break; }
+if (hashtype >= nelem(pdkim_hashes))
+ {
+ DEBUG(D_acl)
+ debug_printf("PDKIM: unrecognised hashname '%s'\n", hashname);
+ return NULL;
}
- ctx->sig->sha1_body = malloc(sizeof(sha1_context));
- if (ctx->sig->sha1_body == NULL) {
- pdkim_free_ctx(ctx);
- return NULL;
+if (!exim_sha_init(&sig->body_hash_ctx, pdkim_hashes[hashtype].exim_hashmethod))
+ {
+ DEBUG(D_acl)
+ debug_printf("PDKIM: hash setup error, possibly nonhandled hashtype\n");
+ return NULL;
}
- sha1_starts(ctx->sig->sha1_body);
- ctx->sig->sha2_body = malloc(sizeof(sha2_context));
- if (ctx->sig->sha2_body == NULL) {
- pdkim_free_ctx(ctx);
- return NULL;
+DEBUG(D_acl)
+ {
+ pdkim_signature s = *sig;
+ ev_ctx vctx;
+
+ debug_printf("PDKIM (checking verify key)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ if (!pdkim_key_from_dns(ctx, &s, &vctx, errstr))
+ debug_printf("WARNING: bad dkim key in dns\n");
+ debug_printf("PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- sha2_starts(ctx->sig->sha2_body,0);
+return sig;
+}
- return ctx;
-};
-#ifdef PDKIM_DEBUG
/* -------------------------------------------------------------------------- */
-DLLEXPORT void pdkim_set_debug_stream(pdkim_ctx *ctx,
- FILE *debug_stream) {
- ctx->debug_stream = debug_stream;
-};
-#endif
-/* -------------------------------------------------------------------------- */
-DLLEXPORT int pdkim_set_optional(pdkim_ctx *ctx,
- char *sign_headers,
- char *identity,
+DLLEXPORT void
+pdkim_set_optional(pdkim_signature * sig,
+ char * sign_headers,
+ char * identity,
int canon_headers,
int canon_body,
long bodylength,
- int algo,
unsigned long created,
- unsigned long expires) {
+ unsigned long expires)
+{
+if (identity)
+ sig->identity = string_copy(US identity);
- if (identity != NULL) {
- ctx->sig->identity = strdup(identity);
- if (ctx->sig->identity == NULL) return PDKIM_ERR_OOM;
- }
+sig->sign_headers = string_copy(sign_headers
+ ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS);
- if (sign_headers != NULL) {
- ctx->sig->sign_headers = strdup(sign_headers);
- if (ctx->sig->sign_headers == NULL) return PDKIM_ERR_OOM;
- }
+sig->canon_headers = canon_headers;
+sig->canon_body = canon_body;
+sig->bodylength = bodylength;
+sig->created = created;
+sig->expires = expires;
- ctx->sig->canon_headers = canon_headers;
- ctx->sig->canon_body = canon_body;
- ctx->sig->bodylength = bodylength;
- ctx->sig->algo = algo;
- ctx->sig->created = created;
- ctx->sig->expires = expires;
+return;
+}
- return PDKIM_OK;
-};
+
+
+void
+pdkim_init_context(pdkim_ctx * ctx, BOOL dot_stuffed,
+ int(*dns_txt_callback)(char *, char *))
+{
+memset(ctx, 0, sizeof(pdkim_ctx));
+ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN;
+ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN);
+DEBUG(D_acl) ctx->dns_txt_callback = dns_txt_callback;
+}
+
+
+void
+pdkim_init(void)
+{
+exim_dkim_init();
+}
+
+
+
+#endif /*DISABLE_DKIM*/
git://git.exim.org / exim.git / blobdiff