+/*
+ * PDKIM - a RFC4871 (DKIM) implementation
+ *
+ * Copyright (C) 2009 Tom Kistner <tom@duncanthrax.net>
+ *
+ * http://duncanthrax.net/pdkim/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* $Cambridge: exim/src/src/pdkim/pdkim.c,v 1.2 2009/06/10 07:34:05 tom Exp $ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "pdkim.h"
+
+#include "sha1.h"
+#include "sha2.h"
+#include "rsa.h"
+#include "base64.h"
+
+#define PDKIM_SIGNATURE_VERSION "1"
+#define PDKIM_PUB_RECORD_VERSION "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;
+};
+
+/* -------------------------------------------------------------------------- */
+/* A bunch of list constants */
+char *pdkim_querymethods[] = {
+ "dns/txt",
+ NULL
+};
+char *pdkim_algos[] = {
+ "rsa-sha256",
+ "rsa-sha1",
+ NULL
+};
+char *pdkim_canons[] = {
+ "simple",
+ "relaxed",
+ NULL
+};
+char *pdkim_hashes[] = {
+ "sha256",
+ "sha1",
+ NULL
+};
+char *pdkim_keytypes[] = {
+ "rsa",
+ NULL
+};
+
+typedef struct pdkim_combined_canon_entry {
+ char *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 }
+};
+
+
+/* -------------------------------------------------------------------------- */
+/* 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);
+}
+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);
+ }
+ 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;
+ }
+ else 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--;
+ }
+ 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);
+};
+
+
+
+/* -------------------------------------------------------------------------- */
+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);
+ }
+}
+
+
+/* -------------------------------------------------------------------------- */
+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);
+ }
+};
+
+
+/* -------------------------------------------------------------------------- */
+DLLEXPORT void pdkim_free_ctx(pdkim_ctx *ctx) {
+ if (ctx) {
+ 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 "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;
+ }
+
+ p = q+1;
+ q = strchr(p,':');
+ }
+
+ if (strcasecmp(p,hname) == 0) {
+ rc = PDKIM_OK;
+ /* Invalidate header name instance in tick-off list */
+ if (do_tick) tick[p-lcopy] = '_';
+ }
+
+ BAIL:
+ free(hname);
+ free(lcopy);
+ return rc;
+}
+
+
+/* -------------------------------------------------------------------------- */
+/* 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));
+ if (relaxed == NULL) return NULL;
+ q = relaxed;
+ while (*p != '\0') {
+ int c = *p;
+ /* Ignore CR & LF */
+ if ( (c == '\r') || (c == '\n') ) {
+ p++;
+ continue;
+ }
+ if ( (c == '\t') || (c == ' ') ) {
+ c = ' '; /* Turns WSP into SP */
+ if (seen_wsp) {
+ p++;
+ continue;
+ }
+ 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++;
+ }
+ *q = '\0';
+ if (crlf) strcat(relaxed,"\r\n");
+ 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;
+}
+
+
+/* -------------------------------------------------------------------------- */
+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;
+ }
+ }
+ else {
+ *q = *p;
+ q++;
+ }
+ p++;
+ }
+ *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;
+}
+
+/* -------------------------------------------------------------------------- */
+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;
+}
+
+
+/* -------------------------------------------------------------------------- */
+#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) {
+
+ /* Ignore FWS */
+ if ( (*p == '\r') || (*p == '\n') )
+ goto NEXT_CHAR;
+
+ /* Fast-forward through header name */
+ if (!past_hname) {
+ if (*p == ':') past_hname = 1;
+ 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;
+ }
+
+ 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 (*p == '=') {
+ if (strcmp(cur_tag->str,"b") == 0) {
+ *q = '='; q++;
+ in_b_val = 1;
+ }
+ where = PDKIM_HDR_VALUE;
+ goto NEXT_CHAR;
+ }
+ }
+
+ 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 (*p == '\0') break;
+
+ if (!in_b_val) {
+ *q = *p;
+ q++;
+ }
+ p++;
+ }
+
+ /* 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;
+ }
+
+ /* 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");
+ }
+ #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;
+ }
+
+ sha1_starts(sig->sha1_body);
+ sha2_starts(sig->sha2_body,0);
+
+ return sig;
+}
+
+
+/* -------------------------------------------------------------------------- */
+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));
+
+ p = raw_record;
+
+ while (1) {
+
+ /* 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;
+ }
+
+ 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 (*p == '=') {
+ where = PDKIM_HDR_VALUE;
+ goto NEXT_CHAR;
+ }
+ }
+
+ 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 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;
+}
+
+
+/* -------------------------------------------------------------------------- */
+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;
+ }
+ canon_data = relaxed_data;
+ canon_len = relaxed_len;
+ }
+
+ /* 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) {
+ 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
+ }
+
+ sig = sig->next;
+ }
+
+ if (relaxed_data != NULL) free(relaxed_data);
+ return PDKIM_OK;
+};
+
+
+/* -------------------------------------------------------------------------- */
+int pdkim_finish_bodyhash(pdkim_ctx *ctx) {
+ pdkim_signature *sig = ctx->sig;
+
+ /* Traverse all signatures */
+ while (sig != NULL) {
+
+ /* 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);
+ 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);
+ }
+ #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;
+ }
+ /* 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 {
+ #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;
+ }
+ }
+
+ sig = sig->next;
+ }
+
+ return PDKIM_OK;
+};
+
+
+
+/* -------------------------------------------------------------------------- */
+/* 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;
+ }
+ /* Unstuff dots */
+ if (memcmp(p,"..",2) == 0) {
+ p++;
+ n--;
+ }
+ }
+
+ /* 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;
+ }
+
+ /* 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--;
+ }
+
+ pdkim_update_bodyhash(ctx,p,n);
+
+ BAIL:
+ ctx->linebuf_offset = 0;
+ return PDKIM_OK;
+}
+
+
+/* -------------------------------------------------------------------------- */
+/* 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;
+
+ /* Traverse all signatures */
+ while (sig != NULL) {
+ pdkim_stringlist *list;
+
+ /* 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;
+ }
+
+ /* Add header to the signed headers list */
+ list = pdkim_append_stringlist(sig->headers,
+ ctx->cur_header->str);
+ if (list == NULL) return PDKIM_ERR_OOM;
+ sig->headers = list;
+
+ NEXT_SIG:
+ sig = sig->next;
+ }
+
+ /* 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
+ }
+ }
+
+ BAIL:
+ pdkim_strclear(ctx->cur_header); /* Re-use existing pdkim_str */
+ return PDKIM_OK;
+};
+
+
+
+/* -------------------------------------------------------------------------- */
+#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;
+ }
+ }
+ return PDKIM_OK;
+};
+
+
+/* -------------------------------------------------------------------------- */
+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;
+ }
+
+ goto BAIL;
+ }
+
+ DONE:
+ rc = strdup(hdr->str);
+
+ BAIL:
+ pdkim_strfree(hdr);
+ if (base64_bh != NULL) free(base64_bh);
+ if (base64_b != NULL) free(base64_b);
+ return rc;
+}
+
+
+/* -------------------------------------------------------------------------- */
+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);
+ }
+ 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);
+ }
+ #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;
+
+ /* SIGNING -------------------------------------------------------------- */
+ if (ctx->mode == PDKIM_MODE_SIGN) {
+ headernames = pdkim_strnew(NULL);
+ if (headernames == NULL) return PDKIM_ERR_OOM;
+ }
+ /* ---------------------------------------------------------------------- */
+
+ 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;
+ }
+ }
+ /* 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) {
+ 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 = hdrs->next;
+ }
+ if (q == NULL) break;
+ p = q+1;
+ }
+ 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);
+
+ /* Create signature header with b= omitted */
+ sig_hdr = pdkim_create_header(ctx->sig,0);
+ }
+ /* VERIFICATION ----------------------------------------------------------- */
+ else {
+ sig_hdr = strdup(sig->rawsig_no_b_val);
+ }
+ /* ------------------------------------------------------------------------ */
+
+ if (sig_hdr == NULL) 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 == NULL) return PDKIM_ERR_OOM;
+ sig_hdr = relaxed_hdr;
+ }
+
+ #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);
+ }
+ #endif
+ }
+
+ free(sig_hdr);
+
+ /* SIGNING ---------------------------------------------------------------- */
+ if (ctx->mode == PDKIM_MODE_SIGN) {
+ rsa_context rsa;
+
+ rsa_init(&rsa,RSA_PKCS_V15,0,NULL,NULL);
+
+ /* 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;
+ }
+
+ 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;
+ }
+
+ rsa_free(&rsa);
+
+ #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);
+ }
+ #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;
+ }
+
+ #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;
+ }
+
+ #ifdef PDKIM_DEBUG
+ if (ctx->debug_stream) {
+ fprintf(ctx->debug_stream,
+ "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
+ }
+ #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;
+ }
+
+ /* 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;
+ }
+
+ /* We have a winner! */
+ 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:
+ rsa_free(&rsa);
+ free(dns_txt_name);
+ free(dns_txt_reply);
+ }
+
+ sig = sig->next;
+ }
+
+ /* If requested, set return pointer to signature(s) */
+ if (return_signatures != NULL) {
+ *return_signatures = ctx->sig;
+ }
+
+ 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;
+
+ 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;
+
+ ctx->mode = PDKIM_MODE_SIGN;
+ ctx->input_mode = input_mode;
+ ctx->sig = sig;
+
+ ctx->sig->domain = strdup(domain);
+ ctx->sig->selector = strdup(selector);
+ ctx->sig->rsa_privkey = strdup(rsa_privkey);
+
+ if (!ctx->sig->domain || !ctx->sig->selector || !ctx->sig->rsa_privkey) {
+ pdkim_free_ctx(ctx);
+ return NULL;
+ }
+
+ ctx->sig->sha1_body = malloc(sizeof(sha1_context));
+ if (ctx->sig->sha1_body == NULL) {
+ pdkim_free_ctx(ctx);
+ 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;
+ }
+ sha2_starts(ctx->sig->sha2_body,0);
+
+ 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,
+ int canon_headers,
+ int canon_body,
+ long bodylength,
+ int algo,
+ unsigned long created,
+ unsigned long expires) {
+
+ if (identity != NULL) {
+ ctx->sig->identity = strdup(identity);
+ if (ctx->sig->identity == NULL) return PDKIM_ERR_OOM;
+ }
+
+ if (sign_headers != NULL) {
+ ctx->sig->sign_headers = strdup(sign_headers);
+ if (ctx->sig->sign_headers == NULL) return PDKIM_ERR_OOM;
+ }
+
+ 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 PDKIM_OK;
+};