* PDKIM - a RFC4871 (DKIM) implementation
*
* Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net>
- * Copyright (C) 2016 Jeremy Harris <jgh@exim.org>
+ * Copyright (C) 2016 - 2017 Jeremy Harris <jgh@exim.org>
*
* http://duncanthrax.net/pdkim/
*
#include "crypt_ver.h"
-#ifdef RSA_OPENSSL
+#ifdef SIGN_OPENSSL
# include <openssl/rsa.h>
# include <openssl/ssl.h>
# include <openssl/err.h>
-#elif defined(RSA_GNUTLS)
+#elif defined(SIGN_GNUTLS)
# include <gnutls/gnutls.h>
# include <gnutls/x509.h>
#endif
#include "pdkim.h"
-#include "rsa.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;
- int tag;
- 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 */
-const char *pdkim_querymethods[] = {
- "dns/txt",
- NULL
-};
-const char *pdkim_algos[] = {
- "rsa-sha256",
- "rsa-sha1",
+const uschar * pdkim_querymethods[] = {
+ US"dns/txt",
NULL
};
-const char *pdkim_canons[] = {
- "simple",
- "relaxed",
+const uschar * pdkim_canons[] = {
+ US"simple",
+ US"relaxed",
NULL
};
-const 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 }
};
-const char *pdkim_keytypes[] = {
- "rsa",
- NULL
+
+const uschar * pdkim_keytypes[] = {
+ US"rsa"
};
typedef struct pdkim_combined_canon_entry {
- const 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};
+
/* -------------------------------------------------------------------------- */
+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);
+}
+
+
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";
+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";
}
}
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_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";
- default: return "PDKIM_VERIFY_UNKNOWN";
+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";
+ }
+}
+
+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)";
}
}
pdkim_hexprint(const uschar *data, int len)
{
int i;
-for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]);
+else debug_printf("<NULL>");
debug_printf("\n");
}
-/* SSS probably want to keep the "stringlist" notion */
-
static pdkim_stringlist *
-pdkim_prepend_stringlist(pdkim_stringlist *base, char *str)
+pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str)
{
-pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist));
+pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist));
-if (!new_entry) return NULL;
memset(new_entry, 0, sizeof(pdkim_stringlist));
-if (!(new_entry->value = strdup(str))) return NULL;
+new_entry->value = string_copy(str);
if (base) new_entry->next = base;
return new_entry;
}
-/* -------------------------------------------------------------------------- */
-/* A small "growing string" implementation to escape malloc/realloc hell */
-/* String package: should be replaced by Exim standard ones */
-/* SSS Ustrcpy */
-
-static pdkim_str *
-pdkim_strnew (const char *cstr)
-{
-unsigned int len = cstr ? strlen(cstr) : 0;
-pdkim_str *p = malloc(sizeof(pdkim_str));
-
-if (!p) return NULL;
-memset(p, 0, sizeof(pdkim_str));
-if (!(p->str = malloc(len+1)))
- {
- free(p);
- return NULL;
- }
-p->allocated = len+1;
-p->len = len;
-if (cstr)
- strcpy(p->str, cstr);
-else
- p->str[p->len] = '\0';
-return p;
-}
-
-
-/*SSS Ustrncat */
-
-static char *
-pdkim_strncat(pdkim_str *str, const 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;
-}
-
-
-/* SSS Ustrcat */
-
-static char *
-pdkim_strcat(pdkim_str *str, const char *cstr)
-{
-return pdkim_strncat(str, cstr, strlen(cstr));
-}
-
-
/* Trim whitespace fore & aft */
-static char *
-pdkim_strtrim(pdkim_str *str)
-{
-char *p = str->str;
-char *q = str->str;
-while (*p == '\t' || *p == ' ') p++; /* skip whitespace */
-while (*p) {*q = *p; q++; p++;} /* dump the leading whitespace */
-*q = '\0';
-while (q != str->str && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) )
- { /* dump trailing whitespace */
- *q = '\0';
- q--;
- }
-str->len = strlen(str->str);
-return str->str;
-}
-
-
-
-static char *
-pdkim_strclear(pdkim_str *str)
-{
-str->str[0] = '\0';
-str->len = 0;
-return str->str;
-}
-
-
-
static void
-pdkim_strfree(pdkim_str *str)
+pdkim_strtrim(gstring * str)
{
-if (!str) return;
-if (str->str) free(str->str);
-free(str);
-}
+uschar * p = str->s;
+uschar * q;
+while (*p == '\t' || *p == ' ') /* dump the leading whitespace */
+ { str->size--; str->ptr--; str->s++; }
-static void
-pdkim_stringlist_free(pdkim_stringlist * e)
-{
-while(e)
- {
- pdkim_stringlist * c = e;
- if (e->value) free(e->value);
- e = e->next;
- free(c);
- }
-}
-
+while ( str->ptr > 0
+ && ((q = str->s + str->ptr - 1), (*q == '\t' || *q == ' '))
+ )
+ str->ptr--; /* dump trailing whitespace */
-
-/* -------------------------------------------------------------------------- */
-
-static void
-pdkim_free_pubkey(pdkim_pubkey *pub)
-{
-if (pub)
- {
- if (pub->version ) free(pub->version);
- if (pub->granularity) free(pub->granularity);
- if (pub->hashes ) free(pub->hashes);
- if (pub->keytype ) free(pub->keytype);
- if (pub->srvtype ) free(pub->srvtype);
- if (pub->notes ) free(pub->notes);
- free(pub);
- }
+(void) string_from_gstring(str);
}
-/* -------------------------------------------------------------------------- */
-
-static void
-pdkim_free_sig(pdkim_signature *sig)
-{
-if (sig)
- {
- pdkim_signature *next = (pdkim_signature *)sig->next;
-
- pdkim_stringlist_free(sig->headers);
- if (sig->selector ) free(sig->selector);
- if (sig->domain ) free(sig->domain);
- if (sig->identity ) free(sig->identity);
- if (sig->copiedheaders ) free(sig->copiedheaders);
- if (sig->rsa_privkey ) free(sig->rsa_privkey);
- if (sig->sign_headers ) free(sig->sign_headers);
- if (sig->signature_header) free(sig->signature_header);
-
- if (sig->pubkey) pdkim_free_pubkey(sig->pubkey);
-
- free(sig);
- if (next) pdkim_free_sig(next);
- }
-}
-
/* -------------------------------------------------------------------------- */
DLLEXPORT void
pdkim_free_ctx(pdkim_ctx *ctx)
{
-if (ctx)
- {
- pdkim_stringlist_free(ctx->headers);
- pdkim_free_sig(ctx->sig);
- pdkim_strfree(ctx->cur_header);
- free(ctx);
- }
}
/* -------------------------------------------------------------------------- */
/* Matches the name of the passed raw "header" against
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" */
+ the entry in tick. Entries can be prefixed for multi- or over-signing,
+ in which case do not invalidate.
+
+ Returns OK for a match, or fail-code
+*/
static int
-header_name_match(const char * header, char * tick)
+header_name_match(const uschar * header, uschar * tick)
{
-char *hname;
-char *lcopy;
-char *p;
-char *q;
-int rc = PDKIM_FAIL;
+const uschar * ticklist = tick;
+int sep = ':';
+BOOL multisign;
+uschar * hname, * p, * ele;
+uschar * hcolon = Ustrchr(header, ':'); /* Get header name */
-/* Get header name */
-char *hcolon = strchr(header, ':');
+if (!hcolon)
+ return PDKIM_FAIL; /* This isn't a header */
-if (!hcolon) return rc; /* This isn't a header */
+/* if we had strncmpic() we wouldn't need this copy */
+hname = string_copyn(header, hcolon-header);
-if (!(hname = malloc((hcolon-header)+1)))
- 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 */
-if (!(lcopy = strdup(tick)))
+while (p = US ticklist, ele = string_nextinlist(&ticklist, &sep, NULL, 0))
{
- free(hname);
- return PDKIM_ERR_OOM;
- }
-p = lcopy;
-q = strchr(p, ':');
-while (q)
+ switch (*ele)
{
- *q = '\0';
+ case '=': case '+': multisign = TRUE; ele++; break;
+ default: multisign = FALSE; break;
+ }
- if (strcasecmp(p, hname) == 0)
+ if (strcmpic(ele, hname) == 0)
{
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- tick[p-lcopy] = '_';
- goto BAIL;
+ if (!multisign)
+ *p = '_'; /* Invalidate this header name instance in tick-off list */
+ return PDKIM_OK;
}
-
- p = q+1;
- q = strchr(p, ':');
}
-
-if (strcasecmp(p, hname) == 0)
- {
- rc = PDKIM_OK;
- /* Invalidate header name instance in tick-off list */
- tick[p-lcopy] = '_';
- }
-
-BAIL:
-free(hname);
-free(lcopy);
-return rc;
+return PDKIM_FAIL;
}
/* -------------------------------------------------------------------------- */
-/* Performs "relaxed" canonicalization of a header. The returned pointer needs
- to be free()d. */
+/* Performs "relaxed" canonicalization of a header. */
-static char *
-pdkim_relax_header (char *header, int crlf)
+static uschar *
+pdkim_relax_header(const uschar * header, BOOL append_crlf)
{
BOOL past_field_name = FALSE;
BOOL seen_wsp = FALSE;
-char *p;
-char *q;
-char *relaxed = malloc(strlen(header)+3);
-
-if (!relaxed) return NULL;
+const uschar * p;
+uschar * relaxed = store_get(Ustrlen(header)+3);
+uschar * q = relaxed;
-q = relaxed;
-for (p = header; *p != '\0'; p++)
+for (p = header; *p; p++)
{
- int c = *p;
- /* Ignore CR & LF */
- if (c == '\r' || c == '\n')
+ uschar c = *p;
+
+ if (c == '\r' || c == '\n') /* Ignore CR & LF */
continue;
if (c == '\t' || c == ' ')
{
else
if (!past_field_name && c == ':')
{
- if (seen_wsp) q--; /* This removes WSP before the colon */
- seen_wsp = TRUE; /* This removes WSP after the colon */
+ 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
}
if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */
-*q = '\0';
-if (crlf) strcat(relaxed, "\r\n");
+if (append_crlf) { *q++ = '\r'; *q++ = '\n'; }
+*q = '\0';
return relaxed;
}
/* -------------------------------------------------------------------------- */
#define PDKIM_QP_ERROR_DECODE -1
-static char *
-pdkim_decode_qp_char(char *qp_p, int *c)
+static const uschar *
+pdkim_decode_qp_char(const uschar *qp_p, int *c)
{
-char *initial_pos = qp_p;
+const uschar *initial_pos = qp_p;
/* Advance one char */
qp_p++;
/* -------------------------------------------------------------------------- */
-static char *
-pdkim_decode_qp(char *str)
+static uschar *
+pdkim_decode_qp(const uschar * str)
{
int nchar = 0;
-char *q;
-char *p = str;
-char *n = malloc(strlen(p)+1);
-
-if (!n) return NULL;
+uschar * q;
+const uschar * p = str;
+uschar * n = store_get(Ustrlen(str)+1);
*n = '\0';
q = n;
-while (*p != '\0')
+while (*p)
{
if (*p == '=')
{
/* -------------------------------------------------------------------------- */
static void
-pdkim_decode_base64(uschar *str, blob * b)
+pdkim_decode_base64(const uschar * str, blob * b)
{
int dlen;
dlen = b64decode(str, &b->data);
b->len = dlen;
}
-/* -------------------------------------------------------------------------- */
-
-static char *
+static uschar *
pdkim_encode_base64(blob * b)
{
-char * ret;
-int old_pool = store_pool;
-
-store_pool = POOL_PERM;
-ret = CS b64encode(b->data, b->len);
-store_pool = old_pool;
-return ret;
+return b64encode(b->data, b->len);
}
#define PDKIM_HDR_VALUE 2
static pdkim_signature *
-pdkim_parse_sig_header(pdkim_ctx *ctx, char *raw_hdr)
+pdkim_parse_sig_header(pdkim_ctx * ctx, uschar * raw_hdr)
{
-pdkim_signature *sig ;
-char *p, *q;
-pdkim_str *cur_tag = NULL;
-pdkim_str *cur_val = NULL;
+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;
-int old_pool = store_pool;
-
-/* There is a store-reset between header & body reception
-so cannot use the main pool. Any allocs done by Exim
-memory-handling must use the perm pool. */
-store_pool = POOL_PERM;
-
-if (!(sig = malloc(sizeof(pdkim_signature)))) return NULL;
+sig = store_get(sizeof(pdkim_signature));
memset(sig, 0, sizeof(pdkim_signature));
sig->bodylength = -1;
-if (!(sig->rawsig_no_b_val = malloc(strlen(raw_hdr)+1)))
- {
- free(sig);
- return NULL;
- }
+/* Set so invalid/missing data error display is accurate */
+sig->version = 0;
+sig->keytype = -1;
+sig->hashtype = -1;
-q = sig->rawsig_no_b_val;
+q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1);
for (p = raw_hdr; ; p++)
{
if (where == PDKIM_HDR_TAG)
{
- if (!cur_tag)
- cur_tag = pdkim_strnew(NULL);
-
if (c >= 'a' && c <= 'z')
- pdkim_strncat(cur_tag, p, 1);
+ cur_tag = string_catn(cur_tag, p, 1);
if (c == '=')
{
- if (strcmp(cur_tag->str, "b") == 0)
+ if (Ustrcmp(string_from_gstring(cur_tag), "b") == 0)
{
- *q = '='; q++;
+ *q++ = '=';
in_b_val = TRUE;
}
where = PDKIM_HDR_VALUE;
if (where == PDKIM_HDR_VALUE)
{
- if (!cur_val)
- cur_val = pdkim_strnew(NULL);
-
if (c == '\r' || c == '\n' || c == ' ' || c == '\t')
goto NEXT_CHAR;
if (c == ';' || c == '\0')
{
- if (cur_tag->len > 0)
+ /* We must have both tag and value, and tags must be one char except
+ for the possibility of "bh". */
+
+ if ( cur_tag && cur_val
+ && (cur_tag->ptr == 1 || *cur_tag->s == 'b')
+ )
{
+ (void) string_from_gstring(cur_val);
pdkim_strtrim(cur_val);
- DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->str, cur_val->str);
+ DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->s, cur_val->s);
- switch (cur_tag->str[0])
+ switch (*cur_tag->s)
{
case 'b':
- if (cur_tag->str[1] == 'h')
- pdkim_decode_base64(US cur_val->str, &sig->bodyhash);
- else
- pdkim_decode_base64(US cur_val->str, &sig->sigdata);
+ switch (cur_tag->s[1])
+ {
+ case '\0': pdkim_decode_base64(cur_val->s, &sig->sighash); break;
+ case 'h': if (cur_tag->ptr == 2)
+ pdkim_decode_base64(cur_val->s, &sig->bodyhash);
+ break;
+ default: break;
+ }
break;
case 'v':
/* We only support version 1, and that is currently the
only version there is. */
- if (strcmp(cur_val->str, PDKIM_SIGNATURE_VERSION) == 0)
- sig->version = 1;
+ sig->version =
+ Ustrcmp(cur_val->s, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1;
break;
case 'a':
- for (i = 0; pdkim_algos[i]; i++)
- if (strcmp(cur_val->str, pdkim_algos[i]) == 0)
- {
- sig->algo = i;
- break;
- }
+ {
+ 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 (strcmp(cur_val->str, pdkim_combined_canons[i].str) == 0)
+ 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;
case 'q':
for (i = 0; pdkim_querymethods[i]; i++)
- if (strcmp(cur_val->str, pdkim_querymethods[i]) == 0)
+ if (Ustrcmp(cur_val->s, pdkim_querymethods[i]) == 0)
{
sig->querymethod = i;
break;
}
break;
case 's':
- sig->selector = strdup(cur_val->str); break;
+ sig->selector = string_copyn(cur_val->s, cur_val->ptr); break;
case 'd':
- sig->domain = strdup(cur_val->str); break;
+ sig->domain = string_copyn(cur_val->s, cur_val->ptr); break;
case 'i':
- sig->identity = pdkim_decode_qp(cur_val->str); break;
+ sig->identity = pdkim_decode_qp(cur_val->s); break;
case 't':
- sig->created = strtoul(cur_val->str, NULL, 10); break;
+ sig->created = strtoul(CS cur_val->s, NULL, 10); break;
case 'x':
- sig->expires = strtoul(cur_val->str, NULL, 10); break;
+ sig->expires = strtoul(CS cur_val->s, NULL, 10); break;
case 'l':
- sig->bodylength = strtol(cur_val->str, NULL, 10); break;
+ sig->bodylength = strtol(CS cur_val->s, NULL, 10); break;
case 'h':
- sig->headernames = string_copy(US cur_val->str); break;
+ sig->headernames = string_copyn(cur_val->s, cur_val->ptr); break;
case 'z':
- sig->copiedheaders = pdkim_decode_qp(cur_val->str); break;
+ sig->copiedheaders = pdkim_decode_qp(cur_val->s); break;
default:
DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
break;
}
}
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
+ cur_tag = cur_val = NULL;
in_b_val = FALSE;
where = PDKIM_HDR_LIMBO;
}
else
- pdkim_strncat(cur_val, p, 1);
+ cur_val = string_catn(cur_val, p, 1);
}
NEXT_CHAR:
*q++ = c;
}
-store_pool = old_pool;
-
-/* 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->version))
- {
- pdkim_free_sig(sig);
- return NULL;
- }
-
*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--; /*XXX questionable code layout; possible bug */
+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, strlen(sig->rawsig_no_b_val));
+ pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val));
debug_printf(
- "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sigdata.len*8);
+ "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sighash.len*8);
debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
-exim_sha_init(&sig->body_hash, sig->algo == PDKIM_ALGO_RSA_SHA1);
+/*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;
}
/* -------------------------------------------------------------------------- */
static pdkim_pubkey *
-pdkim_parse_pubkey_record(pdkim_ctx *ctx, char *raw_record)
+pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record)
{
-pdkim_pubkey *pub;
-char *p;
-pdkim_str *cur_tag = NULL;
-pdkim_str *cur_val = NULL;
-int where = PDKIM_HDR_LIMBO;
+const uschar * ele;
+int sep = ';';
+pdkim_pubkey * pub;
-if (!(pub = malloc(sizeof(pdkim_pubkey)))) return NULL;
+pub = store_get(sizeof(pdkim_pubkey));
memset(pub, 0, sizeof(pdkim_pubkey));
-for (p = raw_record; ; p++)
+while ((ele = string_nextinlist(&raw_record, &sep, NULL, 0)))
{
- char c = *p;
+ const uschar * val;
- /* Ignore FWS */
- if (c == '\r' || c == '\n')
- goto NEXT_CHAR;
-
- if (where == PDKIM_HDR_LIMBO)
+ if ((val = Ustrchr(ele, '=')))
{
- /* In limbo, just wait for a tag-char to appear */
- if (!(c >= 'a' && c <= 'z'))
- goto NEXT_CHAR;
+ int taglen = val++ - ele;
- where = PDKIM_HDR_TAG;
- }
-
- if (where == PDKIM_HDR_TAG)
- {
- if (!cur_tag)
- cur_tag = pdkim_strnew(NULL);
-
- if (c >= 'a' && c <= 'z')
- pdkim_strncat(cur_tag, p, 1);
-
- if (c == '=')
+ DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, ele, val);
+ switch (ele[0])
{
- where = PDKIM_HDR_VALUE;
- goto NEXT_CHAR;
- }
- }
-
- if (where == PDKIM_HDR_VALUE)
- {
- if (!cur_val)
- cur_val = pdkim_strnew(NULL);
-
- if (c == '\r' || c == '\n')
- goto NEXT_CHAR;
-
- if (c == ';' || c == '\0')
- {
- if (cur_tag->len > 0)
- {
- pdkim_strtrim(cur_val);
- DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag->str, cur_val->str);
-
- 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':
- pdkim_decode_base64(US cur_val->str, &pub->key);
- 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, 'y') != NULL) pub->testing = 1;
- if (strchr(cur_val->str, 's') != NULL) pub->no_subdomaining = 1;
- break;
- default:
- DEBUG(D_acl) debug_printf(" Unknown tag encountered\n");
- break;
- }
- }
- pdkim_strclear(cur_tag);
- pdkim_strclear(cur_val);
- where = PDKIM_HDR_LIMBO;
+ 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;
}
- else
- pdkim_strncat(cur_val, p, 1);
}
-
-NEXT_CHAR:
- if (c == '\0') break;
}
/* Set fallback defaults */
-if (!pub->version ) pub->version = strdup(PDKIM_PUB_RECORD_VERSION);
-if (!pub->granularity) pub->granularity = strdup("*");
-if (!pub->keytype ) pub->keytype = strdup("rsa");
-if (!pub->srvtype ) pub->srvtype = strdup("*");
+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;
+ }
+
+if (!pub->granularity) pub->granularity = US"*";
+/*
+if (!pub->keytype ) pub->keytype = US"rsa";
+*/
+if (!pub->srvtype ) pub->srvtype = US"*";
/* p= is required */
if (pub->key.data)
return pub;
-pdkim_free_pubkey(pub);
+DEBUG(D_acl) debug_printf(" Missing p= field\n");
return NULL;
}
/* -------------------------------------------------------------------------- */
-static int
-pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len)
+/* 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)
{
-pdkim_signature *sig = ctx->sig;
-/* Cache relaxed version of data */
-uschar *relaxed_data = NULL;
-int relaxed_len = 0;
+blob * canon_data = orig_data;
+/* Defaults to simple canon (no further treatment necessary) */
-/* Traverse all signatures, updating their hashes. */
-while (sig)
+if (sig->canon_body == PDKIM_CANON_RELAXED)
{
- /* Defaults to simple canon (no further treatment necessary) */
- const uschar *canon_data = CUS data;
- int canon_len = len;
-
- if (sig->canon_body == PDKIM_CANON_RELAXED)
+ /* Relax the line if not done already */
+ if (!relaxed_data)
{
- /* Relax the line if not done already */
- if (!relaxed_data)
- {
- BOOL seen_wsp = FALSE;
- const char *p;
- int q = 0;
+ BOOL seen_wsp = FALSE;
+ const uschar * p;
+ int q = 0;
- if (!(relaxed_data = malloc(len+1)))
- return PDKIM_ERR_OOM;
+ /* 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(). */
- for (p = data; *p; p++)
- {
- char c = *p;
- if (c == '\r')
- {
- if (q > 0 && relaxed_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[q++] = c;
+ 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--;
}
- relaxed_data[q] = '\0';
- relaxed_len = 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;
}
- canon_data = relaxed_data;
- canon_len = relaxed_len;
+ relaxed_data->data[q] = '\0';
+ relaxed_data->len = q;
}
+ canon_data = relaxed_data;
+ }
- /* 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;
-
- if (canon_len > 0)
- {
- exim_sha_update(&sig->body_hash, CCS canon_data, canon_len);
- sig->signed_body_bytes += canon_len;
- DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len);
- }
+/* 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;
- sig = sig->next;
+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);
}
-if (relaxed_data) free(relaxed_data);
-return PDKIM_OK;
+return relaxed_data;
}
/* -------------------------------------------------------------------------- */
-static int
-pdkim_finish_bodyhash(pdkim_ctx *ctx)
+static void
+pdkim_finish_bodyhash(pdkim_ctx * ctx)
{
-pdkim_signature *sig;
+pdkim_signature * sig;
/* Traverse all signatures */
for (sig = ctx->sig; sig; sig = sig->next)
{ /* Finish hashes */
blob bh;
- exim_sha_finish(&sig->body_hash, &bh);
+ exim_sha_finish(&sig->body_hash_ctx, &bh);
DEBUG(D_acl)
{
debug_printf("PDKIM [%s] Body bytes hashed: %lu\n"
- "PDKIM [%s] bh computed: ",
- sig->domain, sig->signed_body_bytes, sig->domain);
+ "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);
}
/* SIGNING -------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN)
+ if (ctx->flags & PDKIM_MODE_SIGN)
{
sig->bodyhash = bh;
sig->bodylength = -1;
}
- /* VERIFICATION --------------------------------------------------------- */
else
- {
- /* Compare bodyhash */
- if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0)
+ /* VERIFICATION --------------------------------------------------------- */
+ /* Be careful that the header sig included a bodyash */
+
+ 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);
}
{
DEBUG(D_acl)
{
- debug_printf("PDKIM [%s] bh signature: ", sig->domain);
- pdkim_hexprint(sig->bodyhash.data,
- exim_sha_hashlen(&sig->body_hash));
+ 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;
}
- }
}
+}
-return PDKIM_OK;
+
+
+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;
}
/* -------------------------------------------------------------------------- */
-/* Callback from pdkim_feed below for processing complete body lines */
+/* Call from pdkim_feed below for processing complete body lines */
-static int
-pdkim_bodyline_complete(pdkim_ctx *ctx)
+static void
+pdkim_bodyline_complete(pdkim_ctx * ctx)
{
-char *p = ctx->linebuf;
-int n = ctx->linebuf_offset;
-pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */
+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->seen_eod) goto BAIL;
+if (ctx->flags & PDKIM_SEEN_EOD) goto all_skip;
/* We've always got one extra byte to stuff a zero ... */
-ctx->linebuf[ctx->linebuf_offset] = '\0';
+ctx->linebuf[line.len] = '\0';
/* Terminate on EOD marker */
-if (memcmp(p, ".\r\n", 3) == 0)
+if (ctx->flags & PDKIM_DOT_TERM)
{
- /* 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 */
- if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE
- && sig->signed_body_bytes == 0
- && ctx->num_buffered_crlf > 0
- )
- pdkim_update_bodyhash(ctx, "\r\n", 2);
+ if (memcmp(line.data, ".\r\n", 3) == 0)
+ { pdkim_body_complete(ctx); return; }
- ctx->seen_eod = TRUE;
- goto BAIL;
- }
-/* Unstuff dots */
-if (memcmp(p, "..", 2) == 0)
- {
- p++;
- n--;
+ /* 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(p, "\r\n", 2) == 0)
+if (memcmp(line.data, "\r\n", 2) == 0)
{
- ctx->num_buffered_crlf++;
- goto BAIL;
+ for (sig = ctx->sig; sig; sig = sig->next) sig->num_buffered_blanklines++;
+ goto all_skip;
}
-if (sig && sig->canon_body == PDKIM_CANON_RELAXED)
+/* Process line for each sig separately */
+for (sig = ctx->sig; sig; sig = sig->next)
{
- /* Lines with just spaces need to be buffered too */
- char *check = p;
- while (memcmp(check, "\r\n", 2) != 0)
+ if (sig->canon_body == PDKIM_CANON_RELAXED)
{
- char c = *check;
+ /* Lines with just spaces need to be buffered too */
+ uschar * cp = line.data;
+ char c;
- if (c != '\t' && c != ' ')
- goto PROCESS;
- check++;
+ while ((c = *cp))
+ {
+ if (c == '\r' && cp[1] == '\n') break;
+ if (c != ' ' && c != '\t') goto sig_process;
+ cp++;
+ }
+
+ sig->num_buffered_blanklines++;
+ goto sig_skip;
}
- ctx->num_buffered_crlf++;
- goto BAIL;
-}
+sig_process:
+ /* At this point, we have a non-empty line, so release the buffered ones. */
-PROCESS:
-/* 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--;
+ while (sig->num_buffered_blanklines)
+ {
+ rnl = pdkim_update_sig_bodyhash(sig, &lineending, rnl);
+ sig->num_buffered_blanklines--;
+ }
+
+ rline = pdkim_update_sig_bodyhash(sig, &line, rline);
+sig_skip: ;
}
-pdkim_update_bodyhash(ctx, p, n);
+if (rnl) store_free(rnl);
+if (rline) store_free(rline);
+
+all_skip:
-BAIL:
ctx->linebuf_offset = 0;
-return PDKIM_OK;
+return;
}
#define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:"
static int
-pdkim_header_complete(pdkim_ctx *ctx)
+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->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--;
- }
+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);
-ctx->num_headers++;
-if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
+if (++ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL;
/* SIGNING -------------------------------------------------------------- */
-if (ctx->mode == PDKIM_MODE_SIGN)
- {
- pdkim_signature *sig;
-
+if (ctx->flags & PDKIM_MODE_SIGN)
for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */
- {
- pdkim_stringlist *list;
/* Add header to the signed headers list (in reverse order) */
- if (!(list = pdkim_prepend_stringlist(sig->headers,
- ctx->cur_header->str)))
- return PDKIM_ERR_OOM;
- sig->headers = list;
- }
- }
+ sig->headers = pdkim_prepend_stringlist(sig->headers, ctx->cur_header->s);
/* VERIFICATION ----------------------------------------------------------- */
/* DKIM-Signature: headers are added to the verification list */
-if (ctx->mode == PDKIM_MODE_VERIFY)
+else
{
- if (strncasecmp(ctx->cur_header->str,
+#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,
- strlen(DKIM_SIGNATURE_HEADERNAME)) == 0)
+ Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0)
{
- pdkim_signature *new_sig;
+ /* 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. */
- /* Create and chain new signature block */
DEBUG(D_acl) debug_printf(
"PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
- if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header->str)))
+ sig = pdkim_parse_sig_header(ctx, ctx->cur_header->s);
+
+ if (!(last_sig = ctx->sig))
+ ctx->sig = sig;
+ else
{
- pdkim_signature *last_sig = ctx->sig;
- if (!last_sig)
- ctx->sig = new_sig;
- else
- {
- while (last_sig->next) last_sig = last_sig->next;
- last_sig->next = new_sig;
- }
+ while (last_sig->next) last_sig = last_sig->next;
+ last_sig->next = sig;
}
- else
- DEBUG(D_acl) debug_printf(
- "Error while parsing signature header\n"
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
- /* every other header is stored for signature verification */
- else
- {
- pdkim_stringlist *list;
-
- if (!(list = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header->str)))
- return PDKIM_ERR_OOM;
- ctx->headers = list;
- }
+ /* all headers are stored for signature verification */
+ ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header->s);
}
BAIL:
-pdkim_strclear(ctx->cur_header); /* Re-use existing pdkim_str */
+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, char *data, int len)
+pdkim_feed(pdkim_ctx * ctx, uschar * data, int len)
{
-int p;
+int p, rc;
+
+/* Alternate EOD signal, used in non-dotstuffing mode */
+if (!data)
+ pdkim_body_complete(ctx);
-for (p = 0; p<len; p++)
+else for (p = 0; p<len; p++)
{
- char c = data[p];
+ uschar c = data[p];
- if (ctx->past_headers)
+ 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 == '\n')
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
{
- int rc = pdkim_bodyline_complete(ctx); /* End of line */
- if (rc != PDKIM_OK) return rc;
+ ctx->flags &= ~PDKIM_SEEN_CR;
+ pdkim_bodyline_complete(ctx);
}
- if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1))
+
+ if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1)
return PDKIM_ERR_LONG_LINE;
}
else
{
/* Processing header byte */
- if (c != '\r')
+ if (c == '\r')
+ ctx->flags |= PDKIM_SEEN_CR;
+ else if (c == '\n')
{
- if (c == '\n')
- {
- if (ctx->seen_lf)
- {
- int rc = pdkim_header_complete(ctx); /* Seen last header line */
- if (rc != PDKIM_OK) return rc;
+ if (!(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */
+ ctx->cur_header = string_catn(ctx->cur_header, CUS "\r", 1);
- ctx->past_headers = TRUE;
- ctx->seen_lf = 0;
- DEBUG(D_acl) debug_printf(
- "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>\n");
- continue;
- }
- else
- ctx->seen_lf = TRUE;
- }
- 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 = FALSE;
+ 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 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)
- if (!(ctx->cur_header = pdkim_strnew(NULL)))
- return PDKIM_ERR_OOM;
-
- if (ctx->cur_header->len < PDKIM_MAX_HEADER_LEN)
- if (!pdkim_strncat(ctx->cur_header, &data[p], 1))
- return PDKIM_ERR_OOM;
+ 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;
}
+
+
+/* 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 char*
+ *
+ * returns uschar * (not nul-terminated)
*
* col: this int holds and receives column number (octets since last '\n')
* str: partial string to append to
* names longer than 78, or bogus col. Input is assumed to be free of line breaks.
*/
-static char *
-pdkim_headcat(int *col, pdkim_str *str, const char * pad,
- const char *intro, const char *payload)
+static gstring *
+pdkim_headcat(int * col, gstring * str,
+ const uschar * pad, const uschar * intro, const uschar * payload)
{
size_t l;
if (pad)
{
- l = strlen(pad);
+ l = Ustrlen(pad);
if (*col + l > 78)
- {
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
- }
- pdkim_strncat(str, pad, l);
+ str = pdkim_hdr_cont(str, col);
+ str = string_catn(str, pad, l);
*col += l;
}
-l = (pad?1:0) + (intro?strlen(intro):0);
+l = (pad?1:0) + (intro?Ustrlen(intro):0);
if (*col + l > 78)
{ /*can't fit intro - start a new line to make room.*/
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
- l = intro?strlen(intro):0;
+ str = pdkim_hdr_cont(str, col);
+ l = intro?Ustrlen(intro):0;
}
-l += payload ? strlen(payload):0 ;
+l += payload ? Ustrlen(payload):0 ;
while (l>77)
{ /* this fragment will not fit on a single line */
if (pad)
{
- pdkim_strcat(str, " ");
+ str = string_catn(str, US" ", 1);
*col += 1;
pad = NULL; /* only want this once */
l--;
if (intro)
{
- size_t sl = strlen(intro);
+ size_t sl = Ustrlen(intro);
- pdkim_strncat(str, intro, sl);
+ str = string_catn(str, intro, sl);
*col += sl;
l -= sl;
intro = NULL; /* only want this once */
if (payload)
{
- size_t sl = strlen(payload);
+ size_t sl = Ustrlen(payload);
size_t chomp = *col+sl < 77 ? sl : 78-*col;
- pdkim_strncat(str, payload, chomp);
+ str = string_catn(str, payload, chomp);
*col += chomp;
payload += chomp;
l -= chomp-1;
}
/* the while precondition tells us it didn't fit. */
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
+ str = pdkim_hdr_cont(str, col);
}
if (*col + l > 78)
{
- pdkim_strcat(str, "\r\n\t");
- *col = 1;
+ str = pdkim_hdr_cont(str, col);
pad = NULL;
}
if (pad)
{
- pdkim_strcat(str, " ");
+ str = string_catn(str, US" ", 1);
*col += 1;
pad = NULL;
}
if (intro)
{
- size_t sl = strlen(intro);
+ size_t sl = Ustrlen(intro);
- pdkim_strncat(str, intro, sl);
+ str = string_catn(str, intro, sl);
*col += sl;
l -= sl;
intro = NULL;
if (payload)
{
- size_t sl = strlen(payload);
+ size_t sl = Ustrlen(payload);
- pdkim_strncat(str, payload, sl);
+ str = string_catn(str, payload, sl);
*col += sl;
}
-return str->str;
+return str;
}
/* -------------------------------------------------------------------------- */
-static char *
-pdkim_create_header(pdkim_signature *sig, BOOL final)
+static uschar *
+pdkim_create_header(pdkim_signature * sig, BOOL final)
{
-char *rc = NULL;
-char *base64_bh = NULL;
-char *base64_b = NULL;
+uschar * base64_bh;
+uschar * base64_b;
int col = 0;
-pdkim_str *hdr;
-pdkim_str *canon_all;
+gstring * hdr;
+gstring * canon_all;
-if (!(hdr = pdkim_strnew("DKIM-Signature: v="PDKIM_SIGNATURE_VERSION)))
- return NULL;
-
-if (!(canon_all = pdkim_strnew(pdkim_canons[sig->canon_headers])))
- goto BAIL;
+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);
-if (!(base64_bh = pdkim_encode_base64(&sig->bodyhash)))
- goto BAIL;
-
-col = strlen(hdr->str);
+hdr = string_cat(NULL, US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION);
+col = hdr->ptr;
/* Required and static bits */
-if ( pdkim_headcat(&col, hdr, ";", "a=", pdkim_algos[sig->algo])
- && pdkim_headcat(&col, hdr, ";", "q=", pdkim_querymethods[sig->querymethod])
- && pdkim_strcat(canon_all, "/")
- && pdkim_strcat(canon_all, pdkim_canons[sig->canon_body])
- && pdkim_headcat(&col, hdr, ";", "c=", canon_all->str)
- && pdkim_headcat(&col, hdr, ";", "d=", sig->domain)
- && pdkim_headcat(&col, hdr, ";", "s=", sig->selector)
- )
+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. */
{
- /* list of header names can be split between items. */
+ uschar * n = string_copy(sig->headernames);
+ uschar * i = US"h=";
+ uschar * s = US";";
+
+ while (*n)
{
- char *n = CS string_copy(sig->headernames);
- char *i = "h=";
- char *s = ";";
+ uschar * c = Ustrchr(n, ':');
- if (!n) goto BAIL;
- while (*n)
- {
- char *c = strchr(n, ':');
+ if (c) *c ='\0';
- if (c) *c ='\0';
+ if (!i)
+ hdr = pdkim_headcat(&col, hdr, NULL, NULL, US":");
- if (!i)
- if (!pdkim_headcat(&col, hdr, NULL, NULL, ":"))
- {
- goto BAIL;
- }
-
- if (!pdkim_headcat(&col, hdr, s, i, n))
- {
- goto BAIL;
- }
+ hdr = pdkim_headcat(&col, hdr, s, i, n);
- if (!c)
- break;
+ if (!c)
+ break;
- n = c+1;
- s = NULL;
- i = NULL;
- }
+ n = c+1;
+ s = NULL;
+ i = NULL;
}
+ }
- if(!pdkim_headcat(&col, hdr, ";", "bh=", base64_bh))
- goto BAIL;
+base64_bh = pdkim_encode_base64(&sig->bodyhash);
+hdr = pdkim_headcat(&col, hdr, US";", US"bh=", base64_bh);
- /* Optional bits */
- if (sig->identity)
- if(!pdkim_headcat(&col, hdr, ";", "i=", sig->identity))
- goto BAIL;
+/* Optional bits */
+if (sig->identity)
+ hdr = pdkim_headcat(&col, hdr, US";", US"i=", sig->identity);
- if (sig->created > 0)
- {
- char minibuf[20];
+if (sig->created > 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created);
+ hdr = pdkim_headcat(&col, hdr, US";", US"t=", minibuf);
+}
- snprintf(minibuf, 20, "%lu", sig->created);
- if(!pdkim_headcat(&col, hdr, ";", "t=", minibuf))
- goto BAIL;
+if (sig->expires > 0)
+ {
+ uschar minibuf[20];
+
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires);
+ hdr = pdkim_headcat(&col, hdr, US";", US"x=", minibuf);
}
- if (sig->expires > 0)
- {
- char minibuf[20];
+if (sig->bodylength >= 0)
+ {
+ uschar minibuf[20];
- snprintf(minibuf, 20, "%lu", sig->expires);
- if(!pdkim_headcat(&col, hdr, ";", "x=", minibuf))
- goto BAIL;
- }
+ snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength);
+ hdr = pdkim_headcat(&col, hdr, US";", US"l=", minibuf);
+ }
- if (sig->bodylength >= 0)
- {
- char minibuf[20];
+/* Preliminary or final version? */
+if (final)
+ {
+ base64_b = pdkim_encode_base64(&sig->sighash);
+ hdr = pdkim_headcat(&col, hdr, US";", US"b=", base64_b);
- snprintf(minibuf, 20, "%lu", sig->bodylength);
- if(!pdkim_headcat(&col, hdr, ";", "l=", minibuf))
- goto BAIL;
- }
+ /* 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"");
+ }
- /* Preliminary or final version? */
- if (final)
- {
- if (!(base64_b = pdkim_encode_base64(&sig->sigdata)))
- goto BAIL;
- if (!pdkim_headcat(&col, hdr, ";", "b=", base64_b))
- goto BAIL;
+return string_from_gstring(hdr);
+}
+
+
+/* -------------------------------------------------------------------------- */
+
+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);
+
+if ( !(dns_txt_reply = ctx->dns_txt_callback(CS dns_txt_name))
+ || dns_txt_reply[0] == '\0'
+ )
+ {
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE;
+ return NULL;
}
- else
- if(!pdkim_headcat(&col, hdr, ";", "b=", ""))
- goto BAIL;
- /* add trailing semicolon: I'm not sure if this is actually needed */
- if (!pdkim_headcat(&col, hdr, NULL, ";", ""))
- goto BAIL;
+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));
}
-rc = strdup(hdr->str);
+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;
-BAIL:
-pdkim_strfree(hdr);
-if (canon_all) pdkim_strfree(canon_all);
-return rc;
+ 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");
+ }
+ return NULL;
+ }
+
+DEBUG(D_acl) debug_printf(
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+
+/* 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_feed_finish(pdkim_ctx * ctx, pdkim_signature ** return_signatures,
+ const uschar ** err)
{
-pdkim_signature *sig = ctx->sig;
-pdkim_str *headernames = NULL; /* Collected signed header names */
+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->len)
+if (ctx->cur_header && ctx->cur_header->ptr > 0)
{
- int rc = pdkim_header_complete(ctx);
- if (rc != PDKIM_OK) return rc;
- pdkim_update_bodyhash(ctx, "\r\n", 2);
+ 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
DEBUG(D_acl) debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
/* Build (and/or evaluate) body hash */
-if (pdkim_finish_bodyhash(ctx) != PDKIM_OK)
- return PDKIM_ERR_OOM;
+pdkim_finish_bodyhash(ctx);
-/* SIGNING -------------------------------------------------------------- */
-if (ctx->mode == PDKIM_MODE_SIGN)
- if (!(headernames = pdkim_strnew(NULL)))
- return PDKIM_ERR_OOM;
-/* ---------------------------------------------------------------------- */
-
-while (sig)
+for (sig = ctx->sig; sig; sig = sig->next)
{
- BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1;
hctx hhash_ctx;
- char * sig_hdr;
+ uschar * sig_hdr = US"";
blob hhash;
- blob hdata;
- int hdata_alloc = 0;
+ gstring * hdata = NULL;
- hdata.data = NULL;
- hdata.len = 0;
+ 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;
+ }
- exim_sha_init(&hhash_ctx, is_sha1);
+ if (ctx->flags & PDKIM_MODE_SIGN)
+ DEBUG(D_acl) debug_printf(
+ "PDKIM >> Headers to be signed: >>>>>>>>>>>>\n"
+ " %s\n",
+ sig->sign_headers);
DEBUG(D_acl) debug_printf(
- "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n");
+ "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>\n");
+
/* SIGNING ---------------------------------------------------------------- */
/* When signing, walk through our header list and add them to the hash. As we
Then append to that list any remaining header names for which there was no
header to sign. */
- if (ctx->mode == PDKIM_MODE_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)
- if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK)
+ {
+ uschar * rh = p->value;
+
+ if (header_name_match(rh, sig->sign_headers) == PDKIM_OK)
{
- uschar * rh;
/* Collect header names (Note: colon presence is guaranteed here) */
- uschar * q = Ustrchr(p->value, ':');
+ g = string_append_listele_n(g, ':', rh, Ustrchr(rh, ':') - rh);
- if (!(pdkim_strncat(headernames, p->value,
- (q - US p->value) + (p->next ? 1 : 0))))
- return PDKIM_ERR_OOM;
-
- rh = sig->canon_headers == PDKIM_CANON_RELAXED
- ? US pdkim_relax_header(p->value, 1) /* cook header for relaxed canon */
- : string_copy(CUS p->value); /* just copy it for simple canon */
- if (!rh)
- return PDKIM_ERR_OOM;
+ 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, CCS rh, Ustrlen(rh));
+ exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh));
/* Remember headers block for signing (when the library cannot do incremental) */
- (void) exim_rsa_data_append(&hdata, &hdata_alloc, rh);
+ hdata = exim_dkim_data_append(hdata, rh);
DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
}
+ }
- l = US sig->sign_headers;
+ /* Any headers we wanted to sign but were not present must also be listed.
+ Ignore elements that have been ticked-off or are marked as never-oversign. */
+
+ l = sig->sign_headers;
while((s = string_nextinlist(&l, &sep, NULL, 0)))
- if (*s != '_')
- { /*SSS string_append_listele() */
- if (headernames->len > 0 && headernames->str[headernames->len-1] != ':')
- if (!(pdkim_strncat(headernames, ":", 1)))
- return PDKIM_ERR_OOM;
- if (!(pdkim_strncat(headernames, CS s, Ustrlen(s))))
- return PDKIM_ERR_OOM;
- }
+ {
+ if (*s == '+') /* skip oversigning marker */
+ s++;
+ if (*s != '_' && *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 ----------------------------------------------------------- */
add the headers to the hash in that order. */
else
{
- uschar * b = string_copy(sig->headernames);
- uschar * p = b;
+ uschar * p = sig->headernames;
uschar * q;
pdkim_stringlist * hdrs;
- if (!b) return PDKIM_ERR_OOM;
-
- /* clear tags */
- for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
- hdrs->tag = 0;
-
- while(1)
+ if (p)
{
- if ((q = Ustrchr(p, ':')))
- *q = '\0';
-
-/*XXX walk the list of headers in same order as received. */
+ /* clear tags */
for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next)
- if ( hdrs->tag == 0
- && strncasecmp(hdrs->value, CS p, Ustrlen(p)) == 0
- && (hdrs->value)[Ustrlen(p)] == ':'
- )
- {
- uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED
- ? US pdkim_relax_header(hdrs->value, 1) /* cook header for relaxed canon */
- : string_copy(CUS hdrs->value); /* just copy it for simple canon */
- if (!rh)
- return PDKIM_ERR_OOM;
-
- /* Feed header to the hash algorithm */
- exim_sha_update(&hhash_ctx, CCS rh, Ustrlen(rh));
-
- DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh));
- hdrs->tag = 1;
- break;
- }
+ hdrs->tag = 0;
- if (!q) break;
- p = q+1;
+ 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);
}
}
DEBUG(D_acl) debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
- /* SIGNING ---------------------------------------------------------------- */
- if (ctx->mode == PDKIM_MODE_SIGN)
+ DEBUG(D_acl)
{
- /* Copy headernames to signature struct */
- sig->headernames = string_copy(US headernames->str);
- pdkim_strfree(headernames);
-
- /* Create signature header with b= omitted */
- sig_hdr = pdkim_create_header(sig, FALSE);
+ 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);
- /* ------------------------------------------------------------------------ */
-
- if (!sig_hdr)
- return PDKIM_ERR_OOM;
-
/* 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)
- return PDKIM_ERR_OOM;
- sig_hdr = relaxed_hdr;
- }
+ 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, strlen(sig_hdr));
+ pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr));
debug_printf(
"PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
}
/* Finalize header hash */
- exim_sha_update(&hhash_ctx, sig_hdr, strlen(sig_hdr));
+ exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr));
exim_sha_finish(&hhash_ctx, &hhash);
DEBUG(D_acl)
{
- debug_printf("PDKIM [%s] hh computed: ", sig->domain);
+ debug_printf("PDKIM [%s] Header %s computed: ",
+ sig->domain, pdkim_hashes[sig->hashtype].dkim_hashname);
pdkim_hexprint(hhash.data, hhash.len);
}
- /* Remember headers block for signing (when the library cannot do incremental) */
- if (ctx->mode == PDKIM_MODE_SIGN)
- (void) exim_rsa_data_append(&hdata, &hdata_alloc, US sig_hdr);
-
- free(sig_hdr);
+ /* 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->mode == PDKIM_MODE_SIGN)
+ if (ctx->flags & PDKIM_MODE_SIGN)
{
es_ctx sctx;
- const uschar * errstr;
- /* Import private key */
- if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &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", errstr);
+ DEBUG(D_acl) debug_printf("signing_init: %s\n", *err);
return PDKIM_ERR_RSA_PRIVKEY;
}
calculated, with GnuTLS we have to sign an entire block of headers
(due to available interfaces) and it recalculates the hash internally. */
-#if defined(RSA_OPENSSL) || defined(RSA_GCRYPT)
- hdata = hhash;
+#if defined(SIGN_GNUTLS)
+ hhash.data = hdata->s;
+ hhash.len = hdata->ptr;
#endif
- if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata)))
+/*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", errstr);
+ DEBUG(D_acl) debug_printf("signing: %s\n", *err);
return PDKIM_ERR_RSA_SIGNING;
}
DEBUG(D_acl)
{
debug_printf( "PDKIM [%s] b computed: ", sig->domain);
- pdkim_hexprint(sig->sigdata.data, sig->sigdata.len);
+ pdkim_hexprint(sig->sighash.data, sig->sighash.len);
}
- if (!(sig->signature_header = pdkim_create_header(sig, TRUE)))
- return PDKIM_ERR_OOM;
+ sig->signature_header = pdkim_create_header(sig, TRUE);
}
/* VERIFICATION ----------------------------------------------------------- */
else
{
ev_ctx vctx;
- const uschar * errstr;
-
- char *dns_txt_name, *dns_txt_reply;
-
- /* Fetch public key for signing domain, from DNS */
- if (!(dns_txt_name = malloc(PDKIM_DNS_TXT_MAX_NAMELEN)))
- return PDKIM_ERR_OOM;
-
- if (!(dns_txt_reply = malloc(PDKIM_DNS_TXT_MAX_RECLEN)))
+ /* 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
+ ) )
{
- free(dns_txt_name);
- return PDKIM_ERR_OOM;
- }
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR;
- 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;
+ DEBUG(D_acl) debug_printf(
+ " Error in DKIM-Signature header: tags missing or invalid\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
goto NEXT_VERIFY;
}
- if ( ctx->dns_txt_callback(dns_txt_name, dns_txt_reply) != PDKIM_OK
- || dns_txt_reply[0] == '\0')
+ /* 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_PUBKEY_UNAVAILABLE;
+ sig->verify_status = PDKIM_VERIFY_INVALID;
+ sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION;
+
+ DEBUG(D_acl) debug_printf(
+ " Error in DKIM-Signature header: unsupported DKIM version\n"
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
goto NEXT_VERIFY;
}
DEBUG(D_acl)
{
- debug_printf(
- "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"
- " Raw record: ");
- pdkim_quoteprint(CUS dns_txt_reply, strlen(dns_txt_reply));
+ debug_printf( "PDKIM [%s] b from mail: ", sig->domain);
+ pdkim_hexprint(sig->sighash.data, sig->sighash.len);
}
- if (!(sig->pubkey = pdkim_parse_pubkey_record(ctx, dns_txt_reply)))
- {
- sig->verify_status = PDKIM_VERIFY_INVALID;
- sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD;
-
- DEBUG(D_acl) debug_printf(
- " Error while parsing public key record\n"
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err)))
goto NEXT_VERIFY;
- }
- DEBUG(D_acl) debug_printf(
- "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ /* If the pubkey limits to a list of specific hashes, ignore sigs that
+ do not have the hash part of the sig algorithm matching */
- /* Import public key */
- if ((errstr = exim_rsa_verify_init(&sig->pubkey->key, &vctx)))
+ if (sig->pubkey->hashes)
{
- 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;
- goto NEXT_VERIFY;
+ 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 ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata)))
+/*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", errstr);
+ 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! (if bodydhash was correct earlier) */
+ /* We have a winner! (if bodyhash was correct earlier) */
if (sig->verify_status == PDKIM_VERIFY_NONE)
sig->verify_status = PDKIM_VERIFY_PASS;
else
debug_printf("\n");
}
-
- free(dns_txt_name);
- free(dns_txt_reply);
}
-
- sig = sig->next;
}
/* If requested, set return pointer to signature(s) */
/* -------------------------------------------------------------------------- */
DLLEXPORT pdkim_ctx *
-pdkim_init_verify(int(*dns_txt_callback)(char *, char *))
+pdkim_init_verify(uschar * (*dns_txt_callback)(char *), BOOL dot_stuffing)
{
-pdkim_ctx *ctx = malloc(sizeof(pdkim_ctx));
+pdkim_ctx * ctx;
-if (!ctx)
- return NULL;
+ctx = store_get(sizeof(pdkim_ctx));
memset(ctx, 0, sizeof(pdkim_ctx));
-if (!(ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN)))
- {
- free(ctx);
- return NULL;
- }
-
-ctx->mode = PDKIM_MODE_VERIFY;
+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;
/* -------------------------------------------------------------------------- */
-DLLEXPORT pdkim_ctx *
-pdkim_init_sign(char *domain, char *selector, char *rsa_privkey, int algo)
+/*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)
{
-pdkim_ctx *ctx;
-pdkim_signature *sig;
+int hashtype;
+pdkim_signature * sig;
-if (!domain || !selector || !rsa_privkey)
+if (!domain || !selector || !privkey)
return NULL;
-if (!(ctx = malloc(sizeof(pdkim_ctx))))
- return NULL;
-memset(ctx, 0, sizeof(pdkim_ctx));
+/* Allocate & init one signature struct */
+
+sig = store_get(sizeof(pdkim_signature));
+memset(sig, 0, sizeof(pdkim_signature));
+
+sig->bodylength = -1;
+
+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 */
-if (!(ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN)))
+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))
{
- free(ctx);
+ DEBUG(D_acl)
+ debug_printf("PDKIM: unrecognised hashname '%s'\n", hashname);
return NULL;
}
-if (!(sig = malloc(sizeof(pdkim_signature))))
+if (!exim_sha_init(&sig->body_hash_ctx, pdkim_hashes[hashtype].exim_hashmethod))
{
- free(ctx->linebuf);
- free(ctx);
+ DEBUG(D_acl)
+ debug_printf("PDKIM: hash setup error, possibly nonhandled hashtype\n");
return NULL;
}
-memset(sig, 0, sizeof(pdkim_signature));
-sig->bodylength = -1;
-
-ctx->mode = PDKIM_MODE_SIGN;
-ctx->sig = sig;
-
-sig->domain = strdup(domain);
-sig->selector = strdup(selector);
-sig->rsa_privkey = strdup(rsa_privkey);
-sig->algo = algo;
-
-if (!sig->domain || !sig->selector || !sig->rsa_privkey)
- goto BAIL;
-
-exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1);
-return ctx;
+DEBUG(D_acl)
+ {
+ pdkim_signature s = *sig;
+ ev_ctx vctx;
-BAIL:
- pdkim_free_ctx(ctx);
- return NULL;
+ 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");
+ }
+return sig;
}
/* -------------------------------------------------------------------------- */
-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,
unsigned long created,
unsigned long expires)
{
-pdkim_signature * sig = ctx->sig;
-
if (identity)
- if (!(sig->identity = strdup(identity)))
- return PDKIM_ERR_OOM;
+ sig->identity = string_copy(US identity);
-if (!(sig->sign_headers = strdup(sign_headers
- ? sign_headers : PDKIM_DEFAULT_SIGN_HEADERS)))
- return PDKIM_ERR_OOM;
+sig->sign_headers = string_copy(sign_headers
+ ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS);
sig->canon_headers = canon_headers;
sig->canon_body = canon_body;
sig->created = created;
sig->expires = expires;
-return PDKIM_OK;
+return;
+}
+
+
+
+void
+pdkim_init_context(pdkim_ctx * ctx, BOOL dot_stuffed,
+ uschar * (*dns_txt_callback)(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_rsa_init();
+exim_dkim_init();
}
git://git.exim.org / exim.git / blobdiff