| 1 | /* |
| 2 | * PDKIM - a RFC4871 (DKIM) implementation |
| 3 | * |
| 4 | * Copyright (C) 2009 - 2015 Tom Kistner <tom@duncanthrax.net> |
| 5 | * |
| 6 | * http://duncanthrax.net/pdkim/ |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along |
| 19 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | */ |
| 22 | |
| 23 | #include <stdlib.h> |
| 24 | #include <stdio.h> |
| 25 | #include <string.h> |
| 26 | #include <ctype.h> |
| 27 | |
| 28 | #include "pdkim.h" |
| 29 | |
| 30 | #include "sha1.h" |
| 31 | #include "sha2.h" |
| 32 | #include "rsa.h" |
| 33 | #include "base64.h" |
| 34 | |
| 35 | #define PDKIM_SIGNATURE_VERSION "1" |
| 36 | #define PDKIM_PUB_RECORD_VERSION "DKIM1" |
| 37 | |
| 38 | #define PDKIM_MAX_HEADER_LEN 65536 |
| 39 | #define PDKIM_MAX_HEADERS 512 |
| 40 | #define PDKIM_MAX_BODY_LINE_LEN 16384 |
| 41 | #define PDKIM_DNS_TXT_MAX_NAMELEN 1024 |
| 42 | #define PDKIM_DEFAULT_SIGN_HEADERS "From:Sender:Reply-To:Subject:Date:"\ |
| 43 | "Message-ID:To:Cc:MIME-Version:Content-Type:"\ |
| 44 | "Content-Transfer-Encoding:Content-ID:"\ |
| 45 | "Content-Description:Resent-Date:Resent-From:"\ |
| 46 | "Resent-Sender:Resent-To:Resent-Cc:"\ |
| 47 | "Resent-Message-ID:In-Reply-To:References:"\ |
| 48 | "List-Id:List-Help:List-Unsubscribe:"\ |
| 49 | "List-Subscribe:List-Post:List-Owner:List-Archive" |
| 50 | |
| 51 | /* -------------------------------------------------------------------------- */ |
| 52 | struct pdkim_stringlist { |
| 53 | char *value; |
| 54 | int tag; |
| 55 | void *next; |
| 56 | }; |
| 57 | |
| 58 | #define PDKIM_STR_ALLOC_FRAG 256 |
| 59 | struct pdkim_str { |
| 60 | char *str; |
| 61 | unsigned int len; |
| 62 | unsigned int allocated; |
| 63 | }; |
| 64 | |
| 65 | /* -------------------------------------------------------------------------- */ |
| 66 | /* A bunch of list constants */ |
| 67 | const char *pdkim_querymethods[] = { |
| 68 | "dns/txt", |
| 69 | NULL |
| 70 | }; |
| 71 | const char *pdkim_algos[] = { |
| 72 | "rsa-sha256", |
| 73 | "rsa-sha1", |
| 74 | NULL |
| 75 | }; |
| 76 | const char *pdkim_canons[] = { |
| 77 | "simple", |
| 78 | "relaxed", |
| 79 | NULL |
| 80 | }; |
| 81 | const char *pdkim_hashes[] = { |
| 82 | "sha256", |
| 83 | "sha1", |
| 84 | NULL |
| 85 | }; |
| 86 | const char *pdkim_keytypes[] = { |
| 87 | "rsa", |
| 88 | NULL |
| 89 | }; |
| 90 | |
| 91 | typedef struct pdkim_combined_canon_entry { |
| 92 | const char *str; |
| 93 | int canon_headers; |
| 94 | int canon_body; |
| 95 | } pdkim_combined_canon_entry; |
| 96 | pdkim_combined_canon_entry pdkim_combined_canons[] = { |
| 97 | { "simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, |
| 98 | { "simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED }, |
| 99 | { "relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, |
| 100 | { "relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED }, |
| 101 | { "simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, |
| 102 | { "relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, |
| 103 | { NULL, 0, 0 } |
| 104 | }; |
| 105 | |
| 106 | |
| 107 | const char *pdkim_verify_status_str(int status) { |
| 108 | switch(status) { |
| 109 | case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE"; |
| 110 | case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID"; |
| 111 | case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL"; |
| 112 | case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS"; |
| 113 | default: return "PDKIM_VERIFY_UNKNOWN"; |
| 114 | } |
| 115 | } |
| 116 | const char *pdkim_verify_ext_status_str(int ext_status) { |
| 117 | switch(ext_status) { |
| 118 | case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY"; |
| 119 | case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE"; |
| 120 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE"; |
| 121 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE"; |
| 122 | case PDKIM_VERIFY_INVALID_PUBKEY_PARSING: return "PDKIM_VERIFY_INVALID_PUBKEY_PARSING"; |
| 123 | default: return "PDKIM_VERIFY_UNKNOWN"; |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | |
| 128 | /* -------------------------------------------------------------------------- */ |
| 129 | /* Print debugging functions */ |
| 130 | #ifdef PDKIM_DEBUG |
| 131 | void pdkim_quoteprint(FILE *stream, const char *data, int len, int lf) { |
| 132 | int i; |
| 133 | const unsigned char *p = (const unsigned char *)data; |
| 134 | |
| 135 | for (i=0;i<len;i++) { |
| 136 | const int c = p[i]; |
| 137 | switch (c) { |
| 138 | case ' ' : fprintf(stream,"{SP}"); break; |
| 139 | case '\t': fprintf(stream,"{TB}"); break; |
| 140 | case '\r': fprintf(stream,"{CR}"); break; |
| 141 | case '\n': fprintf(stream,"{LF}"); break; |
| 142 | case '{' : fprintf(stream,"{BO}"); break; |
| 143 | case '}' : fprintf(stream,"{BC}"); break; |
| 144 | default: |
| 145 | if ( (c < 32) || (c > 127) ) |
| 146 | fprintf(stream,"{%02x}",c); |
| 147 | else |
| 148 | fputc(c,stream); |
| 149 | break; |
| 150 | } |
| 151 | } |
| 152 | if (lf) |
| 153 | fputc('\n',stream); |
| 154 | } |
| 155 | void pdkim_hexprint(FILE *stream, const char *data, int len, int lf) { |
| 156 | int i; |
| 157 | const unsigned char *p = (const unsigned char *)data; |
| 158 | |
| 159 | for (i=0;i<len;i++) { |
| 160 | const int c = p[i]; |
| 161 | fprintf(stream,"%02x",c); |
| 162 | } |
| 163 | if (lf) |
| 164 | fputc('\n',stream); |
| 165 | } |
| 166 | #endif |
| 167 | |
| 168 | |
| 169 | /* -------------------------------------------------------------------------- */ |
| 170 | /* Simple string list implementation for convinience */ |
| 171 | pdkim_stringlist *pdkim_append_stringlist(pdkim_stringlist *base, char *str) { |
| 172 | pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist)); |
| 173 | if (new_entry == NULL) return NULL; |
| 174 | memset(new_entry,0,sizeof(pdkim_stringlist)); |
| 175 | new_entry->value = strdup(str); |
| 176 | if (new_entry->value == NULL) return NULL; |
| 177 | if (base != NULL) { |
| 178 | pdkim_stringlist *last = base; |
| 179 | while (last->next != NULL) { last = last->next; } |
| 180 | last->next = new_entry; |
| 181 | return base; |
| 182 | } |
| 183 | else return new_entry; |
| 184 | } |
| 185 | pdkim_stringlist *pdkim_prepend_stringlist(pdkim_stringlist *base, char *str) { |
| 186 | pdkim_stringlist *new_entry = malloc(sizeof(pdkim_stringlist)); |
| 187 | if (new_entry == NULL) return NULL; |
| 188 | memset(new_entry,0,sizeof(pdkim_stringlist)); |
| 189 | new_entry->value = strdup(str); |
| 190 | if (new_entry->value == NULL) return NULL; |
| 191 | if (base != NULL) { |
| 192 | new_entry->next = base; |
| 193 | } |
| 194 | return new_entry; |
| 195 | } |
| 196 | |
| 197 | |
| 198 | /* -------------------------------------------------------------------------- */ |
| 199 | /* A small "growing string" implementation to escape malloc/realloc hell */ |
| 200 | pdkim_str *pdkim_strnew (const char *cstr) { |
| 201 | unsigned int len = cstr?strlen(cstr):0; |
| 202 | pdkim_str *p = malloc(sizeof(pdkim_str)); |
| 203 | if (p == NULL) return NULL; |
| 204 | memset(p,0,sizeof(pdkim_str)); |
| 205 | p->str = malloc(len+1); |
| 206 | if (p->str == NULL) { |
| 207 | free(p); |
| 208 | return NULL; |
| 209 | } |
| 210 | p->allocated=(len+1); |
| 211 | p->len=len; |
| 212 | if (cstr) strcpy(p->str,cstr); |
| 213 | else p->str[p->len] = '\0'; |
| 214 | return p; |
| 215 | } |
| 216 | char *pdkim_strncat(pdkim_str *str, const char *data, int len) { |
| 217 | if ((str->allocated - str->len) < (len+1)) { |
| 218 | /* Extend the buffer */ |
| 219 | int num_frags = ((len+1)/PDKIM_STR_ALLOC_FRAG)+1; |
| 220 | char *n = realloc(str->str, |
| 221 | (str->allocated+(num_frags*PDKIM_STR_ALLOC_FRAG))); |
| 222 | if (n == NULL) return NULL; |
| 223 | str->str = n; |
| 224 | str->allocated += (num_frags*PDKIM_STR_ALLOC_FRAG); |
| 225 | } |
| 226 | strncpy(&(str->str[str->len]),data,len); |
| 227 | str->len+=len; |
| 228 | str->str[str->len] = '\0'; |
| 229 | return str->str; |
| 230 | } |
| 231 | char *pdkim_strcat(pdkim_str *str, const char *cstr) { |
| 232 | return pdkim_strncat(str, cstr, strlen(cstr)); |
| 233 | } |
| 234 | |
| 235 | char *pdkim_numcat(pdkim_str *str, unsigned long num) { |
| 236 | char minibuf[20]; |
| 237 | snprintf(minibuf,20,"%lu",num); |
| 238 | return pdkim_strcat(str,minibuf); |
| 239 | } |
| 240 | char *pdkim_strtrim(pdkim_str *str) { |
| 241 | char *p = str->str; |
| 242 | char *q = str->str; |
| 243 | while ( (*p != '\0') && ((*p == '\t') || (*p == ' ')) ) p++; |
| 244 | while (*p != '\0') {*q = *p; q++; p++;} |
| 245 | *q = '\0'; |
| 246 | while ( (q != str->str) && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) ) { |
| 247 | *q = '\0'; |
| 248 | q--; |
| 249 | } |
| 250 | str->len = strlen(str->str); |
| 251 | return str->str; |
| 252 | } |
| 253 | char *pdkim_strclear(pdkim_str *str) { |
| 254 | str->str[0] = '\0'; |
| 255 | str->len = 0; |
| 256 | return str->str; |
| 257 | } |
| 258 | void pdkim_strfree(pdkim_str *str) { |
| 259 | if (str == NULL) return; |
| 260 | if (str->str != NULL) free(str->str); |
| 261 | free(str); |
| 262 | } |
| 263 | |
| 264 | |
| 265 | |
| 266 | /* -------------------------------------------------------------------------- */ |
| 267 | void pdkim_free_pubkey(pdkim_pubkey *pub) { |
| 268 | if (pub) { |
| 269 | if (pub->version != NULL) free(pub->version); |
| 270 | if (pub->granularity != NULL) free(pub->granularity); |
| 271 | if (pub->hashes != NULL) free(pub->hashes); |
| 272 | if (pub->keytype != NULL) free(pub->keytype); |
| 273 | if (pub->srvtype != NULL) free(pub->srvtype); |
| 274 | if (pub->notes != NULL) free(pub->notes); |
| 275 | if (pub->key != NULL) free(pub->key); |
| 276 | free(pub); |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | |
| 281 | /* -------------------------------------------------------------------------- */ |
| 282 | void pdkim_free_sig(pdkim_signature *sig) { |
| 283 | if (sig) { |
| 284 | pdkim_signature *next = (pdkim_signature *)sig->next; |
| 285 | |
| 286 | pdkim_stringlist *e = sig->headers; |
| 287 | while(e != NULL) { |
| 288 | pdkim_stringlist *c = e; |
| 289 | if (e->value != NULL) free(e->value); |
| 290 | e = e->next; |
| 291 | free(c); |
| 292 | } |
| 293 | |
| 294 | if (sig->sigdata != NULL) free(sig->sigdata); |
| 295 | if (sig->bodyhash != NULL) free(sig->bodyhash); |
| 296 | if (sig->selector != NULL) free(sig->selector); |
| 297 | if (sig->domain != NULL) free(sig->domain); |
| 298 | if (sig->identity != NULL) free(sig->identity); |
| 299 | if (sig->headernames != NULL) free(sig->headernames); |
| 300 | if (sig->copiedheaders != NULL) free(sig->copiedheaders); |
| 301 | if (sig->rsa_privkey != NULL) free(sig->rsa_privkey); |
| 302 | if (sig->sign_headers != NULL) free(sig->sign_headers); |
| 303 | if (sig->signature_header != NULL) free(sig->signature_header); |
| 304 | if (sig->sha1_body != NULL) free(sig->sha1_body); |
| 305 | if (sig->sha2_body != NULL) free(sig->sha2_body); |
| 306 | |
| 307 | if (sig->pubkey != NULL) pdkim_free_pubkey(sig->pubkey); |
| 308 | |
| 309 | free(sig); |
| 310 | if (next != NULL) pdkim_free_sig(next); |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | |
| 315 | /* -------------------------------------------------------------------------- */ |
| 316 | DLLEXPORT void pdkim_free_ctx(pdkim_ctx *ctx) { |
| 317 | if (ctx) { |
| 318 | pdkim_stringlist *e = ctx->headers; |
| 319 | while(e != NULL) { |
| 320 | pdkim_stringlist *c = e; |
| 321 | if (e->value != NULL) free(e->value); |
| 322 | e = e->next; |
| 323 | free(c); |
| 324 | } |
| 325 | pdkim_free_sig(ctx->sig); |
| 326 | pdkim_strfree(ctx->cur_header); |
| 327 | free(ctx); |
| 328 | } |
| 329 | } |
| 330 | |
| 331 | |
| 332 | /* -------------------------------------------------------------------------- */ |
| 333 | /* Matches the name of the passed raw "header" against |
| 334 | the passed colon-separated "list", starting at entry |
| 335 | "start". Returns the position of the header name in |
| 336 | the list. */ |
| 337 | int header_name_match(const char *header, |
| 338 | char *tick, |
| 339 | int do_tick) { |
| 340 | char *hname; |
| 341 | char *lcopy; |
| 342 | char *p; |
| 343 | char *q; |
| 344 | int rc = PDKIM_FAIL; |
| 345 | |
| 346 | /* Get header name */ |
| 347 | char *hcolon = strchr(header,':'); |
| 348 | if (hcolon == NULL) return rc; /* This isn't a header */ |
| 349 | hname = malloc((hcolon-header)+1); |
| 350 | if (hname == NULL) return PDKIM_ERR_OOM; |
| 351 | memset(hname,0,(hcolon-header)+1); |
| 352 | strncpy(hname,header,(hcolon-header)); |
| 353 | |
| 354 | /* Copy tick-off list locally, so we can punch zeroes into it */ |
| 355 | lcopy = strdup(tick); |
| 356 | if (lcopy == NULL) { |
| 357 | free(hname); |
| 358 | return PDKIM_ERR_OOM; |
| 359 | } |
| 360 | p = lcopy; |
| 361 | q = strchr(p,':'); |
| 362 | while (q != NULL) { |
| 363 | *q = '\0'; |
| 364 | |
| 365 | if (strcasecmp(p,hname) == 0) { |
| 366 | rc = PDKIM_OK; |
| 367 | /* Invalidate header name instance in tick-off list */ |
| 368 | if (do_tick) tick[p-lcopy] = '_'; |
| 369 | goto BAIL; |
| 370 | } |
| 371 | |
| 372 | p = q+1; |
| 373 | q = strchr(p,':'); |
| 374 | } |
| 375 | |
| 376 | if (strcasecmp(p,hname) == 0) { |
| 377 | rc = PDKIM_OK; |
| 378 | /* Invalidate header name instance in tick-off list */ |
| 379 | if (do_tick) tick[p-lcopy] = '_'; |
| 380 | } |
| 381 | |
| 382 | BAIL: |
| 383 | free(hname); |
| 384 | free(lcopy); |
| 385 | return rc; |
| 386 | } |
| 387 | |
| 388 | |
| 389 | /* -------------------------------------------------------------------------- */ |
| 390 | /* Performs "relaxed" canonicalization of a header. The returned pointer needs |
| 391 | to be free()d. */ |
| 392 | char *pdkim_relax_header (char *header, int crlf) { |
| 393 | int past_field_name = 0; |
| 394 | int seen_wsp = 0; |
| 395 | char *p = header; |
| 396 | char *q; |
| 397 | char *relaxed = malloc(strlen(header)+3); |
| 398 | if (relaxed == NULL) return NULL; |
| 399 | q = relaxed; |
| 400 | while (*p != '\0') { |
| 401 | int c = *p; |
| 402 | /* Ignore CR & LF */ |
| 403 | if ( (c == '\r') || (c == '\n') ) { |
| 404 | p++; |
| 405 | continue; |
| 406 | } |
| 407 | if ( (c == '\t') || (c == ' ') ) { |
| 408 | c = ' '; /* Turns WSP into SP */ |
| 409 | if (seen_wsp) { |
| 410 | p++; |
| 411 | continue; |
| 412 | } |
| 413 | else seen_wsp = 1; |
| 414 | } |
| 415 | else { |
| 416 | if ( (!past_field_name) && (c == ':') ) { |
| 417 | if (seen_wsp) q--; /* This removes WSP before the colon */ |
| 418 | seen_wsp = 1; /* This removes WSP after the colon */ |
| 419 | past_field_name = 1; |
| 420 | } |
| 421 | else seen_wsp = 0; |
| 422 | } |
| 423 | /* Lowercase header name */ |
| 424 | if (!past_field_name) c = tolower(c); |
| 425 | *q = c; |
| 426 | p++; |
| 427 | q++; |
| 428 | } |
| 429 | if ((q>relaxed) && (*(q-1) == ' ')) q--; /* Squash eventual trailing SP */ |
| 430 | *q = '\0'; |
| 431 | if (crlf) strcat(relaxed,"\r\n"); |
| 432 | return relaxed; |
| 433 | } |
| 434 | |
| 435 | |
| 436 | /* -------------------------------------------------------------------------- */ |
| 437 | #define PDKIM_QP_ERROR_DECODE -1 |
| 438 | char *pdkim_decode_qp_char(char *qp_p, int *c) { |
| 439 | char *initial_pos = qp_p; |
| 440 | |
| 441 | /* Advance one char */ |
| 442 | qp_p++; |
| 443 | |
| 444 | /* Check for two hex digits and decode them */ |
| 445 | if (isxdigit(*qp_p) && isxdigit(qp_p[1])) { |
| 446 | /* Do hex conversion */ |
| 447 | if (isdigit(*qp_p)) {*c = *qp_p - '0';} |
| 448 | else {*c = toupper(*qp_p) - 'A' + 10;} |
| 449 | *c <<= 4; |
| 450 | if (isdigit(qp_p[1])) {*c |= qp_p[1] - '0';} |
| 451 | else {*c |= toupper(qp_p[1]) - 'A' + 10;} |
| 452 | return qp_p + 2; |
| 453 | } |
| 454 | |
| 455 | /* Illegal char here */ |
| 456 | *c = PDKIM_QP_ERROR_DECODE; |
| 457 | return initial_pos; |
| 458 | } |
| 459 | |
| 460 | |
| 461 | /* -------------------------------------------------------------------------- */ |
| 462 | char *pdkim_decode_qp(char *str) { |
| 463 | int nchar = 0; |
| 464 | char *q; |
| 465 | char *p = str; |
| 466 | char *n = malloc(strlen(p)+1); |
| 467 | if (n == NULL) return NULL; |
| 468 | *n = '\0'; |
| 469 | q = n; |
| 470 | while (*p != '\0') { |
| 471 | if (*p == '=') { |
| 472 | p = pdkim_decode_qp_char(p,&nchar); |
| 473 | if (nchar >= 0) { |
| 474 | *q = nchar; |
| 475 | q++; |
| 476 | continue; |
| 477 | } |
| 478 | } |
| 479 | else { |
| 480 | *q = *p; |
| 481 | q++; |
| 482 | } |
| 483 | p++; |
| 484 | } |
| 485 | *q = '\0'; |
| 486 | return n; |
| 487 | } |
| 488 | |
| 489 | |
| 490 | /* -------------------------------------------------------------------------- */ |
| 491 | char *pdkim_decode_base64(char *str, int *num_decoded) { |
| 492 | int dlen = 0; |
| 493 | char *res; |
| 494 | |
| 495 | base64_decode(NULL, &dlen, (unsigned char *)str, strlen(str)); |
| 496 | res = malloc(dlen+1); |
| 497 | if (res == NULL) return NULL; |
| 498 | if (base64_decode((unsigned char *)res,&dlen,(unsigned char *)str,strlen(str)) != 0) { |
| 499 | free(res); |
| 500 | return NULL; |
| 501 | } |
| 502 | if (num_decoded != NULL) *num_decoded = dlen; |
| 503 | return res; |
| 504 | } |
| 505 | |
| 506 | /* -------------------------------------------------------------------------- */ |
| 507 | char *pdkim_encode_base64(char *str, int num) { |
| 508 | int dlen = 0; |
| 509 | char *res; |
| 510 | |
| 511 | base64_encode(NULL, &dlen, (unsigned char *)str, num); |
| 512 | res = malloc(dlen+1); |
| 513 | if (res == NULL) return NULL; |
| 514 | if (base64_encode((unsigned char *)res,&dlen,(unsigned char *)str,num) != 0) { |
| 515 | free(res); |
| 516 | return NULL; |
| 517 | } |
| 518 | return res; |
| 519 | } |
| 520 | |
| 521 | |
| 522 | /* -------------------------------------------------------------------------- */ |
| 523 | #define PDKIM_HDR_LIMBO 0 |
| 524 | #define PDKIM_HDR_TAG 1 |
| 525 | #define PDKIM_HDR_VALUE 2 |
| 526 | pdkim_signature *pdkim_parse_sig_header(pdkim_ctx *ctx, char *raw_hdr) { |
| 527 | pdkim_signature *sig ; |
| 528 | char *p,*q; |
| 529 | pdkim_str *cur_tag = NULL; |
| 530 | pdkim_str *cur_val = NULL; |
| 531 | int past_hname = 0; |
| 532 | int in_b_val = 0; |
| 533 | int where = PDKIM_HDR_LIMBO; |
| 534 | int i; |
| 535 | |
| 536 | sig = malloc(sizeof(pdkim_signature)); |
| 537 | if (sig == NULL) return NULL; |
| 538 | memset(sig,0,sizeof(pdkim_signature)); |
| 539 | sig->bodylength = -1; |
| 540 | |
| 541 | sig->rawsig_no_b_val = malloc(strlen(raw_hdr)+1); |
| 542 | if (sig->rawsig_no_b_val == NULL) { |
| 543 | free(sig); |
| 544 | return NULL; |
| 545 | } |
| 546 | |
| 547 | p = raw_hdr; |
| 548 | q = sig->rawsig_no_b_val; |
| 549 | |
| 550 | while (1) { |
| 551 | |
| 552 | /* Ignore FWS */ |
| 553 | if ( (*p == '\r') || (*p == '\n') ) |
| 554 | goto NEXT_CHAR; |
| 555 | |
| 556 | /* Fast-forward through header name */ |
| 557 | if (!past_hname) { |
| 558 | if (*p == ':') past_hname = 1; |
| 559 | goto NEXT_CHAR; |
| 560 | } |
| 561 | |
| 562 | if (where == PDKIM_HDR_LIMBO) { |
| 563 | /* In limbo, just wait for a tag-char to appear */ |
| 564 | if (!((*p >= 'a') && (*p <= 'z'))) |
| 565 | goto NEXT_CHAR; |
| 566 | |
| 567 | where = PDKIM_HDR_TAG; |
| 568 | } |
| 569 | |
| 570 | if (where == PDKIM_HDR_TAG) { |
| 571 | if (cur_tag == NULL) |
| 572 | cur_tag = pdkim_strnew(NULL); |
| 573 | |
| 574 | if ((*p >= 'a') && (*p <= 'z')) |
| 575 | pdkim_strncat(cur_tag,p,1); |
| 576 | |
| 577 | if (*p == '=') { |
| 578 | if (strcmp(cur_tag->str,"b") == 0) { |
| 579 | *q = '='; q++; |
| 580 | in_b_val = 1; |
| 581 | } |
| 582 | where = PDKIM_HDR_VALUE; |
| 583 | goto NEXT_CHAR; |
| 584 | } |
| 585 | } |
| 586 | |
| 587 | if (where == PDKIM_HDR_VALUE) { |
| 588 | if (cur_val == NULL) |
| 589 | cur_val = pdkim_strnew(NULL); |
| 590 | |
| 591 | if ( (*p == '\r') || (*p == '\n') || (*p == ' ') || (*p == '\t') ) |
| 592 | goto NEXT_CHAR; |
| 593 | |
| 594 | if ( (*p == ';') || (*p == '\0') ) { |
| 595 | if (cur_tag->len > 0) { |
| 596 | pdkim_strtrim(cur_val); |
| 597 | #ifdef PDKIM_DEBUG |
| 598 | if (ctx->debug_stream) |
| 599 | fprintf(ctx->debug_stream, "%s=%s\n", cur_tag->str, cur_val->str); |
| 600 | #endif |
| 601 | switch (cur_tag->str[0]) { |
| 602 | case 'b': |
| 603 | switch (cur_tag->str[1]) { |
| 604 | case 'h': |
| 605 | sig->bodyhash = pdkim_decode_base64(cur_val->str,&(sig->bodyhash_len)); |
| 606 | break; |
| 607 | default: |
| 608 | sig->sigdata = pdkim_decode_base64(cur_val->str,&(sig->sigdata_len)); |
| 609 | break; |
| 610 | } |
| 611 | break; |
| 612 | case 'v': |
| 613 | if (strcmp(cur_val->str,PDKIM_SIGNATURE_VERSION) == 0) { |
| 614 | /* We only support version 1, and that is currently the |
| 615 | only version there is. */ |
| 616 | sig->version = 1; |
| 617 | } |
| 618 | break; |
| 619 | case 'a': |
| 620 | i = 0; |
| 621 | while (pdkim_algos[i] != NULL) { |
| 622 | if (strcmp(cur_val->str,pdkim_algos[i]) == 0 ) { |
| 623 | sig->algo = i; |
| 624 | break; |
| 625 | } |
| 626 | i++; |
| 627 | } |
| 628 | break; |
| 629 | case 'c': |
| 630 | i = 0; |
| 631 | while (pdkim_combined_canons[i].str != NULL) { |
| 632 | if (strcmp(cur_val->str,pdkim_combined_canons[i].str) == 0 ) { |
| 633 | sig->canon_headers = pdkim_combined_canons[i].canon_headers; |
| 634 | sig->canon_body = pdkim_combined_canons[i].canon_body; |
| 635 | break; |
| 636 | } |
| 637 | i++; |
| 638 | } |
| 639 | break; |
| 640 | case 'q': |
| 641 | i = 0; |
| 642 | while (pdkim_querymethods[i] != NULL) { |
| 643 | if (strcmp(cur_val->str,pdkim_querymethods[i]) == 0 ) { |
| 644 | sig->querymethod = i; |
| 645 | break; |
| 646 | } |
| 647 | i++; |
| 648 | } |
| 649 | break; |
| 650 | case 's': |
| 651 | sig->selector = strdup(cur_val->str); |
| 652 | break; |
| 653 | case 'd': |
| 654 | sig->domain = strdup(cur_val->str); |
| 655 | break; |
| 656 | case 'i': |
| 657 | sig->identity = pdkim_decode_qp(cur_val->str); |
| 658 | break; |
| 659 | case 't': |
| 660 | sig->created = strtoul(cur_val->str,NULL,10); |
| 661 | break; |
| 662 | case 'x': |
| 663 | sig->expires = strtoul(cur_val->str,NULL,10); |
| 664 | break; |
| 665 | case 'l': |
| 666 | sig->bodylength = strtol(cur_val->str,NULL,10); |
| 667 | break; |
| 668 | case 'h': |
| 669 | sig->headernames = strdup(cur_val->str); |
| 670 | break; |
| 671 | case 'z': |
| 672 | sig->copiedheaders = pdkim_decode_qp(cur_val->str); |
| 673 | break; |
| 674 | default: |
| 675 | #ifdef PDKIM_DEBUG |
| 676 | if (ctx->debug_stream) |
| 677 | fprintf(ctx->debug_stream, "Unknown tag encountered\n"); |
| 678 | #endif |
| 679 | break; |
| 680 | } |
| 681 | } |
| 682 | pdkim_strclear(cur_tag); |
| 683 | pdkim_strclear(cur_val); |
| 684 | in_b_val = 0; |
| 685 | where = PDKIM_HDR_LIMBO; |
| 686 | goto NEXT_CHAR; |
| 687 | } |
| 688 | else pdkim_strncat(cur_val,p,1); |
| 689 | } |
| 690 | |
| 691 | NEXT_CHAR: |
| 692 | if (*p == '\0') break; |
| 693 | |
| 694 | if (!in_b_val) { |
| 695 | *q = *p; |
| 696 | q++; |
| 697 | } |
| 698 | p++; |
| 699 | } |
| 700 | |
| 701 | /* Make sure the most important bits are there. */ |
| 702 | if (!(sig->domain && (*(sig->domain) != '\0') && |
| 703 | sig->selector && (*(sig->selector) != '\0') && |
| 704 | sig->headernames && (*(sig->headernames) != '\0') && |
| 705 | sig->bodyhash && |
| 706 | sig->sigdata && |
| 707 | sig->version)) { |
| 708 | pdkim_free_sig(sig); |
| 709 | return NULL; |
| 710 | } |
| 711 | |
| 712 | *q = '\0'; |
| 713 | /* Chomp raw header. The final newline must not be added to the signature. */ |
| 714 | q--; |
| 715 | while( (q > sig->rawsig_no_b_val) && ((*q == '\r') || (*q == '\n')) ) { |
| 716 | *q = '\0'; q--; |
| 717 | } |
| 718 | |
| 719 | #ifdef PDKIM_DEBUG |
| 720 | if (ctx->debug_stream) { |
| 721 | fprintf(ctx->debug_stream, |
| 722 | "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 723 | pdkim_quoteprint(ctx->debug_stream, |
| 724 | sig->rawsig_no_b_val, |
| 725 | strlen(sig->rawsig_no_b_val), 1); |
| 726 | fprintf(ctx->debug_stream, |
| 727 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 728 | } |
| 729 | #endif |
| 730 | |
| 731 | sig->sha1_body = malloc(sizeof(sha1_context)); |
| 732 | if (sig->sha1_body == NULL) { |
| 733 | pdkim_free_sig(sig); |
| 734 | return NULL; |
| 735 | } |
| 736 | sig->sha2_body = malloc(sizeof(sha2_context)); |
| 737 | if (sig->sha2_body == NULL) { |
| 738 | pdkim_free_sig(sig); |
| 739 | return NULL; |
| 740 | } |
| 741 | |
| 742 | sha1_starts(sig->sha1_body); |
| 743 | sha2_starts(sig->sha2_body,0); |
| 744 | |
| 745 | return sig; |
| 746 | } |
| 747 | |
| 748 | |
| 749 | /* -------------------------------------------------------------------------- */ |
| 750 | pdkim_pubkey *pdkim_parse_pubkey_record(pdkim_ctx *ctx, char *raw_record) { |
| 751 | pdkim_pubkey *pub ; |
| 752 | char *p; |
| 753 | pdkim_str *cur_tag = NULL; |
| 754 | pdkim_str *cur_val = NULL; |
| 755 | int where = PDKIM_HDR_LIMBO; |
| 756 | |
| 757 | pub = malloc(sizeof(pdkim_pubkey)); |
| 758 | if (pub == NULL) return NULL; |
| 759 | memset(pub,0,sizeof(pdkim_pubkey)); |
| 760 | |
| 761 | p = raw_record; |
| 762 | |
| 763 | while (1) { |
| 764 | |
| 765 | /* Ignore FWS */ |
| 766 | if ( (*p == '\r') || (*p == '\n') ) |
| 767 | goto NEXT_CHAR; |
| 768 | |
| 769 | if (where == PDKIM_HDR_LIMBO) { |
| 770 | /* In limbo, just wait for a tag-char to appear */ |
| 771 | if (!((*p >= 'a') && (*p <= 'z'))) |
| 772 | goto NEXT_CHAR; |
| 773 | |
| 774 | where = PDKIM_HDR_TAG; |
| 775 | } |
| 776 | |
| 777 | if (where == PDKIM_HDR_TAG) { |
| 778 | if (cur_tag == NULL) |
| 779 | cur_tag = pdkim_strnew(NULL); |
| 780 | |
| 781 | if ((*p >= 'a') && (*p <= 'z')) |
| 782 | pdkim_strncat(cur_tag,p,1); |
| 783 | |
| 784 | if (*p == '=') { |
| 785 | where = PDKIM_HDR_VALUE; |
| 786 | goto NEXT_CHAR; |
| 787 | } |
| 788 | } |
| 789 | |
| 790 | if (where == PDKIM_HDR_VALUE) { |
| 791 | if (cur_val == NULL) |
| 792 | cur_val = pdkim_strnew(NULL); |
| 793 | |
| 794 | if ( (*p == '\r') || (*p == '\n') ) |
| 795 | goto NEXT_CHAR; |
| 796 | |
| 797 | if ( (*p == ';') || (*p == '\0') ) { |
| 798 | if (cur_tag->len > 0) { |
| 799 | pdkim_strtrim(cur_val); |
| 800 | #ifdef PDKIM_DEBUG |
| 801 | if (ctx->debug_stream) |
| 802 | fprintf(ctx->debug_stream, "%s=%s\n", cur_tag->str, cur_val->str); |
| 803 | #endif |
| 804 | switch (cur_tag->str[0]) { |
| 805 | case 'v': |
| 806 | /* This tag isn't evaluated because: |
| 807 | - We only support version DKIM1. |
| 808 | - Which is the default for this value (set below) |
| 809 | - Other versions are currently not specified. */ |
| 810 | break; |
| 811 | case 'h': |
| 812 | pub->hashes = strdup(cur_val->str); |
| 813 | break; |
| 814 | case 'g': |
| 815 | pub->granularity = strdup(cur_val->str); |
| 816 | break; |
| 817 | case 'n': |
| 818 | pub->notes = pdkim_decode_qp(cur_val->str); |
| 819 | break; |
| 820 | case 'p': |
| 821 | pub->key = pdkim_decode_base64(cur_val->str,&(pub->key_len)); |
| 822 | break; |
| 823 | case 'k': |
| 824 | pub->hashes = strdup(cur_val->str); |
| 825 | break; |
| 826 | case 's': |
| 827 | pub->srvtype = strdup(cur_val->str); |
| 828 | break; |
| 829 | case 't': |
| 830 | if (strchr(cur_val->str,'y') != NULL) pub->testing = 1; |
| 831 | if (strchr(cur_val->str,'s') != NULL) pub->no_subdomaining = 1; |
| 832 | break; |
| 833 | default: |
| 834 | #ifdef PDKIM_DEBUG |
| 835 | if (ctx->debug_stream) |
| 836 | fprintf(ctx->debug_stream, "Unknown tag encountered\n"); |
| 837 | #endif |
| 838 | break; |
| 839 | } |
| 840 | } |
| 841 | pdkim_strclear(cur_tag); |
| 842 | pdkim_strclear(cur_val); |
| 843 | where = PDKIM_HDR_LIMBO; |
| 844 | goto NEXT_CHAR; |
| 845 | } |
| 846 | else pdkim_strncat(cur_val,p,1); |
| 847 | } |
| 848 | |
| 849 | NEXT_CHAR: |
| 850 | if (*p == '\0') break; |
| 851 | p++; |
| 852 | } |
| 853 | |
| 854 | /* Set fallback defaults */ |
| 855 | if (pub->version == NULL) pub->version = strdup(PDKIM_PUB_RECORD_VERSION); |
| 856 | if (pub->granularity == NULL) pub->granularity = strdup("*"); |
| 857 | if (pub->keytype == NULL) pub->keytype = strdup("rsa"); |
| 858 | if (pub->srvtype == NULL) pub->srvtype = strdup("*"); |
| 859 | |
| 860 | /* p= is required */ |
| 861 | if (pub->key == NULL) { |
| 862 | pdkim_free_pubkey(pub); |
| 863 | return NULL; |
| 864 | } |
| 865 | |
| 866 | return pub; |
| 867 | } |
| 868 | |
| 869 | |
| 870 | /* -------------------------------------------------------------------------- */ |
| 871 | int pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len) { |
| 872 | pdkim_signature *sig = ctx->sig; |
| 873 | /* Cache relaxed version of data */ |
| 874 | char *relaxed_data = NULL; |
| 875 | int relaxed_len = 0; |
| 876 | |
| 877 | /* Traverse all signatures, updating their hashes. */ |
| 878 | while (sig != NULL) { |
| 879 | /* Defaults to simple canon (no further treatment necessary) */ |
| 880 | const char *canon_data = data; |
| 881 | int canon_len = len; |
| 882 | |
| 883 | if (sig->canon_body == PDKIM_CANON_RELAXED) { |
| 884 | /* Relax the line if not done already */ |
| 885 | if (relaxed_data == NULL) { |
| 886 | int seen_wsp = 0; |
| 887 | const char *p = data; |
| 888 | int q = 0; |
| 889 | relaxed_data = malloc(len+1); |
| 890 | if (relaxed_data == NULL) return PDKIM_ERR_OOM; |
| 891 | while (*p != '\0') { |
| 892 | char c = *p; |
| 893 | if (c == '\r') { |
| 894 | if ( (q > 0) && (relaxed_data[q-1] == ' ') ) q--; |
| 895 | } |
| 896 | else if ( (c == '\t') || (c == ' ') ) { |
| 897 | c = ' '; /* Turns WSP into SP */ |
| 898 | if (seen_wsp) { |
| 899 | p++; |
| 900 | continue; |
| 901 | } |
| 902 | else seen_wsp = 1; |
| 903 | } |
| 904 | else seen_wsp = 0; |
| 905 | relaxed_data[q++] = c; |
| 906 | p++; |
| 907 | } |
| 908 | relaxed_data[q] = '\0'; |
| 909 | relaxed_len = q; |
| 910 | } |
| 911 | canon_data = relaxed_data; |
| 912 | canon_len = relaxed_len; |
| 913 | } |
| 914 | |
| 915 | /* Make sure we don't exceed the to-be-signed body length */ |
| 916 | if ((sig->bodylength >= 0) && |
| 917 | ((sig->signed_body_bytes+(unsigned long)canon_len) > sig->bodylength)) |
| 918 | canon_len = (sig->bodylength - sig->signed_body_bytes); |
| 919 | |
| 920 | if (canon_len > 0) { |
| 921 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) |
| 922 | sha1_update(sig->sha1_body,(unsigned char *)canon_data,canon_len); |
| 923 | else |
| 924 | sha2_update(sig->sha2_body,(unsigned char *)canon_data,canon_len); |
| 925 | sig->signed_body_bytes += canon_len; |
| 926 | #ifdef PDKIM_DEBUG |
| 927 | if (ctx->debug_stream!=NULL) |
| 928 | pdkim_quoteprint(ctx->debug_stream,canon_data,canon_len,0); |
| 929 | #endif |
| 930 | } |
| 931 | |
| 932 | sig = sig->next; |
| 933 | } |
| 934 | |
| 935 | if (relaxed_data != NULL) free(relaxed_data); |
| 936 | return PDKIM_OK; |
| 937 | } |
| 938 | |
| 939 | |
| 940 | /* -------------------------------------------------------------------------- */ |
| 941 | int pdkim_finish_bodyhash(pdkim_ctx *ctx) { |
| 942 | pdkim_signature *sig = ctx->sig; |
| 943 | |
| 944 | /* Traverse all signatures */ |
| 945 | while (sig != NULL) { |
| 946 | |
| 947 | /* Finish hashes */ |
| 948 | unsigned char bh[32]; /* SHA-256 = 32 Bytes, SHA-1 = 20 Bytes */ |
| 949 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) |
| 950 | sha1_finish(sig->sha1_body,bh); |
| 951 | else |
| 952 | sha2_finish(sig->sha2_body,bh); |
| 953 | |
| 954 | #ifdef PDKIM_DEBUG |
| 955 | if (ctx->debug_stream) { |
| 956 | fprintf(ctx->debug_stream, "PDKIM [%s] Body bytes hashed: %lu\n", |
| 957 | sig->domain, sig->signed_body_bytes); |
| 958 | fprintf(ctx->debug_stream, "PDKIM [%s] bh computed: ", sig->domain); |
| 959 | pdkim_hexprint(ctx->debug_stream, (char *)bh, |
| 960 | (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32,1); |
| 961 | } |
| 962 | #endif |
| 963 | |
| 964 | /* SIGNING -------------------------------------------------------------- */ |
| 965 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 966 | sig->bodyhash_len = (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32; |
| 967 | sig->bodyhash = malloc(sig->bodyhash_len); |
| 968 | if (sig->bodyhash == NULL) return PDKIM_ERR_OOM; |
| 969 | memcpy(sig->bodyhash,bh,sig->bodyhash_len); |
| 970 | |
| 971 | /* If bodylength limit is set, and we have received less bytes |
| 972 | than the requested amount, effectively remove the limit tag. */ |
| 973 | if (sig->signed_body_bytes < sig->bodylength) sig->bodylength = -1; |
| 974 | } |
| 975 | /* VERIFICATION --------------------------------------------------------- */ |
| 976 | else { |
| 977 | /* Compare bodyhash */ |
| 978 | if (memcmp(bh,sig->bodyhash, |
| 979 | (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32) == 0) { |
| 980 | #ifdef PDKIM_DEBUG |
| 981 | if (ctx->debug_stream) |
| 982 | fprintf(ctx->debug_stream, "PDKIM [%s] Body hash verified OK\n", |
| 983 | sig->domain); |
| 984 | #endif |
| 985 | } |
| 986 | else { |
| 987 | #ifdef PDKIM_DEBUG |
| 988 | if (ctx->debug_stream) { |
| 989 | fprintf(ctx->debug_stream, "PDKIM [%s] Body hash did NOT verify\n", |
| 990 | sig->domain); |
| 991 | fprintf(ctx->debug_stream, "PDKIM [%s] bh signature: ", sig->domain); |
| 992 | pdkim_hexprint(ctx->debug_stream, sig->bodyhash, |
| 993 | (sig->algo == PDKIM_ALGO_RSA_SHA1)?20:32,1); |
| 994 | } |
| 995 | #endif |
| 996 | sig->verify_status = PDKIM_VERIFY_FAIL; |
| 997 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; |
| 998 | } |
| 999 | } |
| 1000 | |
| 1001 | sig = sig->next; |
| 1002 | } |
| 1003 | |
| 1004 | return PDKIM_OK; |
| 1005 | } |
| 1006 | |
| 1007 | |
| 1008 | |
| 1009 | /* -------------------------------------------------------------------------- */ |
| 1010 | /* Callback from pdkim_feed below for processing complete body lines */ |
| 1011 | int pdkim_bodyline_complete(pdkim_ctx *ctx) { |
| 1012 | char *p = ctx->linebuf; |
| 1013 | int n = ctx->linebuf_offset; |
| 1014 | |
| 1015 | /* Ignore extra data if we've seen the end-of-data marker */ |
| 1016 | if (ctx->seen_eod) goto BAIL; |
| 1017 | |
| 1018 | /* We've always got one extra byte to stuff a zero ... */ |
| 1019 | ctx->linebuf[(ctx->linebuf_offset)] = '\0'; |
| 1020 | |
| 1021 | if (ctx->input_mode == PDKIM_INPUT_SMTP) { |
| 1022 | /* Terminate on EOD marker */ |
| 1023 | if (memcmp(p,".\r\n",3) == 0) { |
| 1024 | ctx->seen_eod = 1; |
| 1025 | goto BAIL; |
| 1026 | } |
| 1027 | /* Unstuff dots */ |
| 1028 | if (memcmp(p,"..",2) == 0) { |
| 1029 | p++; |
| 1030 | n--; |
| 1031 | } |
| 1032 | } |
| 1033 | |
| 1034 | /* Empty lines need to be buffered until we find a non-empty line */ |
| 1035 | if (memcmp(p,"\r\n",2) == 0) { |
| 1036 | ctx->num_buffered_crlf++; |
| 1037 | goto BAIL; |
| 1038 | } |
| 1039 | |
| 1040 | /* At this point, we have a non-empty line, so release the buffered ones. */ |
| 1041 | while (ctx->num_buffered_crlf) { |
| 1042 | pdkim_update_bodyhash(ctx,"\r\n",2); |
| 1043 | ctx->num_buffered_crlf--; |
| 1044 | } |
| 1045 | |
| 1046 | pdkim_update_bodyhash(ctx,p,n); |
| 1047 | |
| 1048 | BAIL: |
| 1049 | ctx->linebuf_offset = 0; |
| 1050 | return PDKIM_OK; |
| 1051 | } |
| 1052 | |
| 1053 | |
| 1054 | /* -------------------------------------------------------------------------- */ |
| 1055 | /* Callback from pdkim_feed below for processing complete headers */ |
| 1056 | #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" |
| 1057 | int pdkim_header_complete(pdkim_ctx *ctx) { |
| 1058 | pdkim_signature *sig = ctx->sig; |
| 1059 | |
| 1060 | /* Special case: The last header can have an extra \r appended */ |
| 1061 | if ( (ctx->cur_header->len > 1) && |
| 1062 | (ctx->cur_header->str[(ctx->cur_header->len)-1] == '\r') ) { |
| 1063 | ctx->cur_header->str[(ctx->cur_header->len)-1] = '\0'; |
| 1064 | ctx->cur_header->len--; |
| 1065 | } |
| 1066 | |
| 1067 | ctx->num_headers++; |
| 1068 | if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; |
| 1069 | |
| 1070 | /* SIGNING -------------------------------------------------------------- */ |
| 1071 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 1072 | /* Traverse all signatures */ |
| 1073 | while (sig != NULL) { |
| 1074 | pdkim_stringlist *list; |
| 1075 | |
| 1076 | if (header_name_match(ctx->cur_header->str, |
| 1077 | sig->sign_headers? |
| 1078 | sig->sign_headers: |
| 1079 | PDKIM_DEFAULT_SIGN_HEADERS, 0) != PDKIM_OK) goto NEXT_SIG; |
| 1080 | |
| 1081 | /* Add header to the signed headers list (in reverse order) */ |
| 1082 | list = pdkim_prepend_stringlist(sig->headers, |
| 1083 | ctx->cur_header->str); |
| 1084 | if (list == NULL) return PDKIM_ERR_OOM; |
| 1085 | sig->headers = list; |
| 1086 | |
| 1087 | NEXT_SIG: |
| 1088 | sig = sig->next; |
| 1089 | } |
| 1090 | } |
| 1091 | |
| 1092 | /* DKIM-Signature: headers are added to the verification list */ |
| 1093 | if (ctx->mode == PDKIM_MODE_VERIFY) { |
| 1094 | if (strncasecmp(ctx->cur_header->str, |
| 1095 | DKIM_SIGNATURE_HEADERNAME, |
| 1096 | strlen(DKIM_SIGNATURE_HEADERNAME)) == 0) { |
| 1097 | pdkim_signature *new_sig; |
| 1098 | /* Create and chain new signature block */ |
| 1099 | #ifdef PDKIM_DEBUG |
| 1100 | if (ctx->debug_stream) |
| 1101 | fprintf(ctx->debug_stream, |
| 1102 | "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 1103 | #endif |
| 1104 | new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header->str); |
| 1105 | if (new_sig != NULL) { |
| 1106 | pdkim_signature *last_sig = ctx->sig; |
| 1107 | if (last_sig == NULL) { |
| 1108 | ctx->sig = new_sig; |
| 1109 | } |
| 1110 | else { |
| 1111 | while (last_sig->next != NULL) { last_sig = last_sig->next; } |
| 1112 | last_sig->next = new_sig; |
| 1113 | } |
| 1114 | } |
| 1115 | else { |
| 1116 | #ifdef PDKIM_DEBUG |
| 1117 | if (ctx->debug_stream) { |
| 1118 | fprintf(ctx->debug_stream,"Error while parsing signature header\n"); |
| 1119 | fprintf(ctx->debug_stream, |
| 1120 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1121 | } |
| 1122 | #endif |
| 1123 | } |
| 1124 | } |
| 1125 | /* every other header is stored for signature verification */ |
| 1126 | else { |
| 1127 | pdkim_stringlist *list; |
| 1128 | |
| 1129 | list = pdkim_prepend_stringlist(ctx->headers, |
| 1130 | ctx->cur_header->str); |
| 1131 | if (list == NULL) return PDKIM_ERR_OOM; |
| 1132 | ctx->headers = list; |
| 1133 | } |
| 1134 | } |
| 1135 | |
| 1136 | BAIL: |
| 1137 | pdkim_strclear(ctx->cur_header); /* Re-use existing pdkim_str */ |
| 1138 | return PDKIM_OK; |
| 1139 | } |
| 1140 | |
| 1141 | |
| 1142 | |
| 1143 | /* -------------------------------------------------------------------------- */ |
| 1144 | #define HEADER_BUFFER_FRAG_SIZE 256 |
| 1145 | DLLEXPORT int pdkim_feed (pdkim_ctx *ctx, |
| 1146 | char *data, |
| 1147 | int len) { |
| 1148 | int p; |
| 1149 | for (p=0;p<len;p++) { |
| 1150 | char c = data[p]; |
| 1151 | if (ctx->past_headers) { |
| 1152 | /* Processing body byte */ |
| 1153 | ctx->linebuf[(ctx->linebuf_offset)++] = c; |
| 1154 | if (c == '\n') { |
| 1155 | int rc = pdkim_bodyline_complete(ctx); /* End of line */ |
| 1156 | if (rc != PDKIM_OK) return rc; |
| 1157 | } |
| 1158 | if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1)) |
| 1159 | return PDKIM_ERR_LONG_LINE; |
| 1160 | } |
| 1161 | else { |
| 1162 | /* Processing header byte */ |
| 1163 | if (c != '\r') { |
| 1164 | if (c == '\n') { |
| 1165 | if (ctx->seen_lf) { |
| 1166 | int rc = pdkim_header_complete(ctx); /* Seen last header line */ |
| 1167 | if (rc != PDKIM_OK) return rc; |
| 1168 | ctx->past_headers = 1; |
| 1169 | ctx->seen_lf = 0; |
| 1170 | #ifdef PDKIM_DEBUG |
| 1171 | if (ctx->debug_stream) |
| 1172 | fprintf(ctx->debug_stream, |
| 1173 | "PDKIM >> Hashed body data, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 1174 | #endif |
| 1175 | continue; |
| 1176 | } |
| 1177 | else ctx->seen_lf = 1; |
| 1178 | } |
| 1179 | else if (ctx->seen_lf) { |
| 1180 | if (! ((c == '\t') || (c == ' '))) { |
| 1181 | int rc = pdkim_header_complete(ctx); /* End of header */ |
| 1182 | if (rc != PDKIM_OK) return rc; |
| 1183 | } |
| 1184 | ctx->seen_lf = 0; |
| 1185 | } |
| 1186 | } |
| 1187 | if (ctx->cur_header == NULL) { |
| 1188 | ctx->cur_header = pdkim_strnew(NULL); |
| 1189 | if (ctx->cur_header == NULL) return PDKIM_ERR_OOM; |
| 1190 | } |
| 1191 | if (ctx->cur_header->len < PDKIM_MAX_HEADER_LEN) |
| 1192 | if (pdkim_strncat(ctx->cur_header,&data[p],1) == NULL) |
| 1193 | return PDKIM_ERR_OOM; |
| 1194 | } |
| 1195 | } |
| 1196 | return PDKIM_OK; |
| 1197 | } |
| 1198 | |
| 1199 | /* |
| 1200 | * RFC 5322 specifies that header line length SHOULD be no more than 78 |
| 1201 | * lets make it so! |
| 1202 | * pdkim_headcat |
| 1203 | * returns char* |
| 1204 | * |
| 1205 | * col: this int holds and receives column number (octets since last '\n') |
| 1206 | * str: partial string to append to |
| 1207 | * pad: padding, split line or space after before or after eg: ";" |
| 1208 | * intro: - must join to payload eg "h=", usually the tag name |
| 1209 | * payload: eg base64 data - long data can be split arbitrarily. |
| 1210 | * |
| 1211 | * this code doesn't fold the header in some of the places that RFC4871 |
| 1212 | * allows: As per RFC5322(2.2.3) it only folds before or after tag-value |
| 1213 | * pairs and inside long values. it also always spaces or breaks after the |
| 1214 | * "pad" |
| 1215 | * |
| 1216 | * no guarantees are made for output given out-of range input. like tag |
| 1217 | * names loinger than 78, or bogus col. Input is assumed to be free of line breaks. |
| 1218 | */ |
| 1219 | |
| 1220 | static char *pdkim_headcat(int *col, pdkim_str *str, const char*pad,const char *intro, const char *payload ) { |
| 1221 | size_t l; |
| 1222 | if( pad) |
| 1223 | { |
| 1224 | l = strlen(pad); |
| 1225 | if( *col + l > 78 ) |
| 1226 | { |
| 1227 | pdkim_strcat(str, "\r\n\t"); |
| 1228 | *col=1; |
| 1229 | } |
| 1230 | pdkim_strncat(str, pad,l); |
| 1231 | *col +=l; |
| 1232 | } |
| 1233 | |
| 1234 | l=(pad?1:0) + (intro?strlen(intro):0 ); |
| 1235 | |
| 1236 | if( *col + l > 78 ) |
| 1237 | { /*can't fit intro - start a new line to make room.*/ |
| 1238 | pdkim_strcat(str, "\r\n\t"); |
| 1239 | *col=1; |
| 1240 | l= intro?strlen(intro):0; |
| 1241 | } |
| 1242 | |
| 1243 | l += payload ? strlen(payload):0 ; |
| 1244 | |
| 1245 | while(l>77) |
| 1246 | { /* this fragment will not fit on a single line */ |
| 1247 | if( pad ) |
| 1248 | { |
| 1249 | pdkim_strcat(str, " "); |
| 1250 | *col +=1; |
| 1251 | pad=NULL; // only want this once |
| 1252 | l--; |
| 1253 | } |
| 1254 | if( intro ) |
| 1255 | { |
| 1256 | size_t sl=strlen(intro); |
| 1257 | pdkim_strncat(str, intro,sl); |
| 1258 | *col +=sl; |
| 1259 | l-=sl; |
| 1260 | intro=NULL; // only want this once |
| 1261 | } |
| 1262 | if(payload) |
| 1263 | { |
| 1264 | size_t sl=strlen(payload); |
| 1265 | size_t chomp = *col+sl < 77 ? sl : 78-*col; |
| 1266 | pdkim_strncat(str, payload,chomp); |
| 1267 | *col +=chomp; |
| 1268 | payload+=chomp; |
| 1269 | l-=chomp-1; |
| 1270 | } |
| 1271 | // the while precondition tells us it didn't fit. |
| 1272 | pdkim_strcat(str, "\r\n\t"); |
| 1273 | *col=1; |
| 1274 | } |
| 1275 | if( *col + l > 78 ) |
| 1276 | { |
| 1277 | pdkim_strcat(str, "\r\n\t"); |
| 1278 | *col=1; |
| 1279 | pad=NULL; |
| 1280 | } |
| 1281 | |
| 1282 | if( pad ) |
| 1283 | { |
| 1284 | pdkim_strcat(str, " "); |
| 1285 | *col +=1; |
| 1286 | pad=NULL; |
| 1287 | } |
| 1288 | |
| 1289 | if( intro ) |
| 1290 | { |
| 1291 | size_t sl=strlen(intro); |
| 1292 | pdkim_strncat(str, intro,sl); |
| 1293 | *col +=sl; |
| 1294 | l-=sl; |
| 1295 | intro=NULL; |
| 1296 | } |
| 1297 | if(payload) |
| 1298 | { |
| 1299 | size_t sl=strlen(payload); |
| 1300 | pdkim_strncat(str, payload,sl); |
| 1301 | *col +=sl; |
| 1302 | } |
| 1303 | |
| 1304 | return str->str; |
| 1305 | } |
| 1306 | |
| 1307 | /* -------------------------------------------------------------------------- */ |
| 1308 | char *pdkim_create_header(pdkim_signature *sig, int final) { |
| 1309 | char *rc = NULL; |
| 1310 | char *base64_bh = NULL; |
| 1311 | char *base64_b = NULL; |
| 1312 | int col=0; |
| 1313 | pdkim_str *hdr = pdkim_strnew("DKIM-Signature: v="PDKIM_SIGNATURE_VERSION); |
| 1314 | if (hdr == NULL) return NULL; |
| 1315 | pdkim_str *canon_all = pdkim_strnew(pdkim_canons[sig->canon_headers]); |
| 1316 | if (canon_all == NULL) goto BAIL; |
| 1317 | |
| 1318 | base64_bh = pdkim_encode_base64(sig->bodyhash, sig->bodyhash_len); |
| 1319 | if (base64_bh == NULL) goto BAIL; |
| 1320 | |
| 1321 | col=strlen(hdr->str); |
| 1322 | |
| 1323 | /* Required and static bits */ |
| 1324 | if ( |
| 1325 | pdkim_headcat(&col,hdr,";","a=",pdkim_algos[sig->algo]) && |
| 1326 | pdkim_headcat(&col,hdr,";","q=",pdkim_querymethods[sig->querymethod]) && |
| 1327 | pdkim_strcat(canon_all,"/") && |
| 1328 | pdkim_strcat(canon_all,pdkim_canons[sig->canon_body]) && |
| 1329 | pdkim_headcat(&col,hdr,";","c=",canon_all->str) && |
| 1330 | pdkim_headcat(&col,hdr,";","d=",sig->domain) && |
| 1331 | pdkim_headcat(&col,hdr,";","s=",sig->selector) |
| 1332 | ) { |
| 1333 | /* list of eader names can be split between items. */ |
| 1334 | { |
| 1335 | char *n=strdup(sig->headernames); |
| 1336 | char *f=n; |
| 1337 | char *i="h="; |
| 1338 | char *s=";"; |
| 1339 | if(!n) goto BAIL; |
| 1340 | while (*n) |
| 1341 | { |
| 1342 | char *c=strchr(n,':'); |
| 1343 | if(c) *c='\0'; |
| 1344 | if(!i) |
| 1345 | { |
| 1346 | if (!pdkim_headcat(&col,hdr,NULL,NULL,":")) |
| 1347 | { |
| 1348 | free(f); |
| 1349 | goto BAIL; |
| 1350 | } |
| 1351 | } |
| 1352 | if( !pdkim_headcat(&col,hdr,s,i,n)) |
| 1353 | { |
| 1354 | free(f); |
| 1355 | goto BAIL; |
| 1356 | } |
| 1357 | if(c) n=c+1 ; else break; |
| 1358 | s=NULL; |
| 1359 | i=NULL; |
| 1360 | } |
| 1361 | free(f); |
| 1362 | } |
| 1363 | if(!pdkim_headcat(&col,hdr,";","bh=",base64_bh)) |
| 1364 | goto BAIL; |
| 1365 | |
| 1366 | /* Optional bits */ |
| 1367 | if (sig->identity != NULL) { |
| 1368 | if(!pdkim_headcat(&col,hdr,";","i=",sig->identity)){ |
| 1369 | goto BAIL; |
| 1370 | } |
| 1371 | } |
| 1372 | |
| 1373 | if (sig->created > 0) { |
| 1374 | char minibuf[20]; |
| 1375 | snprintf(minibuf,20,"%lu",sig->created); |
| 1376 | if(!pdkim_headcat(&col,hdr,";","t=",minibuf)) { |
| 1377 | goto BAIL; |
| 1378 | } |
| 1379 | } |
| 1380 | if (sig->expires > 0) { |
| 1381 | char minibuf[20]; |
| 1382 | snprintf(minibuf,20,"%lu",sig->expires); |
| 1383 | if(!pdkim_headcat(&col,hdr,";","x=",minibuf)) { |
| 1384 | goto BAIL; |
| 1385 | } |
| 1386 | } |
| 1387 | if (sig->bodylength >= 0) { |
| 1388 | char minibuf[20]; |
| 1389 | snprintf(minibuf,20,"%lu",sig->bodylength); |
| 1390 | if(!pdkim_headcat(&col,hdr,";","l=",minibuf)) { |
| 1391 | goto BAIL; |
| 1392 | } |
| 1393 | } |
| 1394 | |
| 1395 | /* Preliminary or final version? */ |
| 1396 | if (final) { |
| 1397 | base64_b = pdkim_encode_base64(sig->sigdata, sig->sigdata_len); |
| 1398 | if (base64_b == NULL) goto BAIL; |
| 1399 | if(!pdkim_headcat(&col,hdr,";","b=",base64_b)) goto BAIL; |
| 1400 | } |
| 1401 | else { |
| 1402 | if(!pdkim_headcat(&col,hdr,";","b=","")) goto BAIL; |
| 1403 | } |
| 1404 | |
| 1405 | /* add trailing semicolon: I'm not sure if this is actually needed */ |
| 1406 | if(!pdkim_headcat(&col,hdr,NULL,";","")) goto BAIL; |
| 1407 | |
| 1408 | goto DONE; |
| 1409 | } |
| 1410 | |
| 1411 | DONE: |
| 1412 | rc = strdup(hdr->str); |
| 1413 | |
| 1414 | BAIL: |
| 1415 | pdkim_strfree(hdr); |
| 1416 | if (canon_all != NULL) pdkim_strfree(canon_all); |
| 1417 | if (base64_bh != NULL) free(base64_bh); |
| 1418 | if (base64_b != NULL) free(base64_b); |
| 1419 | return rc; |
| 1420 | } |
| 1421 | |
| 1422 | |
| 1423 | /* -------------------------------------------------------------------------- */ |
| 1424 | DLLEXPORT int pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) { |
| 1425 | pdkim_signature *sig = ctx->sig; |
| 1426 | pdkim_str *headernames = NULL; /* Collected signed header names */ |
| 1427 | |
| 1428 | /* Check if we must still flush a (partial) header. If that is the |
| 1429 | case, the message has no body, and we must compute a body hash |
| 1430 | out of '<CR><LF>' */ |
| 1431 | if (ctx->cur_header && ctx->cur_header->len) { |
| 1432 | int rc = pdkim_header_complete(ctx); |
| 1433 | if (rc != PDKIM_OK) return rc; |
| 1434 | pdkim_update_bodyhash(ctx,"\r\n",2); |
| 1435 | } |
| 1436 | else { |
| 1437 | /* For non-smtp input, check if there's an unfinished line in the |
| 1438 | body line buffer. If that is the case, we must add a CRLF to the |
| 1439 | hash to properly terminate the message. */ |
| 1440 | if ((ctx->input_mode == PDKIM_INPUT_NORMAL) && ctx->linebuf_offset) { |
| 1441 | pdkim_update_bodyhash(ctx, ctx->linebuf, ctx->linebuf_offset); |
| 1442 | pdkim_update_bodyhash(ctx,"\r\n",2); |
| 1443 | } |
| 1444 | #ifdef PDKIM_DEBUG |
| 1445 | if (ctx->debug_stream) |
| 1446 | fprintf(ctx->debug_stream, |
| 1447 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1448 | #endif |
| 1449 | } |
| 1450 | |
| 1451 | /* Build (and/or evaluate) body hash */ |
| 1452 | if (pdkim_finish_bodyhash(ctx) != PDKIM_OK) return PDKIM_ERR_OOM; |
| 1453 | |
| 1454 | /* SIGNING -------------------------------------------------------------- */ |
| 1455 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 1456 | headernames = pdkim_strnew(NULL); |
| 1457 | if (headernames == NULL) return PDKIM_ERR_OOM; |
| 1458 | } |
| 1459 | /* ---------------------------------------------------------------------- */ |
| 1460 | |
| 1461 | while (sig != NULL) { |
| 1462 | sha1_context sha1_headers; |
| 1463 | sha2_context sha2_headers; |
| 1464 | char *sig_hdr; |
| 1465 | char headerhash[32]; |
| 1466 | |
| 1467 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) |
| 1468 | sha1_starts(&sha1_headers); |
| 1469 | else |
| 1470 | sha2_starts(&sha2_headers,0); |
| 1471 | |
| 1472 | #ifdef PDKIM_DEBUG |
| 1473 | if (ctx->debug_stream) |
| 1474 | fprintf(ctx->debug_stream, |
| 1475 | "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n"); |
| 1476 | #endif |
| 1477 | |
| 1478 | /* SIGNING ---------------------------------------------------------------- */ |
| 1479 | /* When signing, walk through our header list and add them to the hash. As we |
| 1480 | go, construct a list of the header's names to use for the h= parameter. */ |
| 1481 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 1482 | pdkim_stringlist *p = sig->headers; |
| 1483 | while (p != NULL) { |
| 1484 | char *rh = NULL; |
| 1485 | /* Collect header names (Note: colon presence is guaranteed here) */ |
| 1486 | char *q = strchr(p->value,':'); |
| 1487 | if (pdkim_strncat(headernames, p->value, |
| 1488 | (q-(p->value))+((p->next==NULL)?0:1)) == NULL) |
| 1489 | return PDKIM_ERR_OOM; |
| 1490 | |
| 1491 | if (sig->canon_headers == PDKIM_CANON_RELAXED) |
| 1492 | rh = pdkim_relax_header(p->value,1); /* cook header for relaxed canon */ |
| 1493 | else |
| 1494 | rh = strdup(p->value); /* just copy it for simple canon */ |
| 1495 | |
| 1496 | if (rh == NULL) return PDKIM_ERR_OOM; |
| 1497 | |
| 1498 | /* Feed header to the hash algorithm */ |
| 1499 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) |
| 1500 | sha1_update(&(sha1_headers),(unsigned char *)rh,strlen(rh)); |
| 1501 | else |
| 1502 | sha2_update(&(sha2_headers),(unsigned char *)rh,strlen(rh)); |
| 1503 | #ifdef PDKIM_DEBUG |
| 1504 | if (ctx->debug_stream) |
| 1505 | pdkim_quoteprint(ctx->debug_stream, rh, strlen(rh), 1); |
| 1506 | #endif |
| 1507 | free(rh); |
| 1508 | p = p->next; |
| 1509 | } |
| 1510 | } |
| 1511 | /* VERIFICATION ----------------------------------------------------------- */ |
| 1512 | /* When verifying, walk through the header name list in the h= parameter and |
| 1513 | add the headers to the hash in that order. */ |
| 1514 | else { |
| 1515 | char *b = strdup(sig->headernames); |
| 1516 | char *p = b; |
| 1517 | char *q = NULL; |
| 1518 | pdkim_stringlist *hdrs = ctx->headers; |
| 1519 | |
| 1520 | if (b == NULL) return PDKIM_ERR_OOM; |
| 1521 | |
| 1522 | /* clear tags */ |
| 1523 | while (hdrs != NULL) { |
| 1524 | hdrs->tag = 0; |
| 1525 | hdrs = hdrs->next; |
| 1526 | } |
| 1527 | |
| 1528 | while(1) { |
| 1529 | hdrs = ctx->headers; |
| 1530 | q = strchr(p,':'); |
| 1531 | if (q != NULL) *q = '\0'; |
| 1532 | while (hdrs != NULL) { |
| 1533 | if ( (hdrs->tag == 0) && |
| 1534 | (strncasecmp(hdrs->value,p,strlen(p)) == 0) && |
| 1535 | ((hdrs->value)[strlen(p)] == ':') ) { |
| 1536 | char *rh = NULL; |
| 1537 | if (sig->canon_headers == PDKIM_CANON_RELAXED) |
| 1538 | rh = pdkim_relax_header(hdrs->value,1); /* cook header for relaxed canon */ |
| 1539 | else |
| 1540 | rh = strdup(hdrs->value); /* just copy it for simple canon */ |
| 1541 | if (rh == NULL) return PDKIM_ERR_OOM; |
| 1542 | /* Feed header to the hash algorithm */ |
| 1543 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) |
| 1544 | sha1_update(&(sha1_headers),(unsigned char *)rh,strlen(rh)); |
| 1545 | else |
| 1546 | sha2_update(&(sha2_headers),(unsigned char *)rh,strlen(rh)); |
| 1547 | #ifdef PDKIM_DEBUG |
| 1548 | if (ctx->debug_stream) |
| 1549 | pdkim_quoteprint(ctx->debug_stream, rh, strlen(rh), 1); |
| 1550 | #endif |
| 1551 | free(rh); |
| 1552 | hdrs->tag = 1; |
| 1553 | break; |
| 1554 | } |
| 1555 | hdrs = hdrs->next; |
| 1556 | } |
| 1557 | if (q == NULL) break; |
| 1558 | p = q+1; |
| 1559 | } |
| 1560 | free(b); |
| 1561 | } |
| 1562 | |
| 1563 | #ifdef PDKIM_DEBUG |
| 1564 | if (ctx->debug_stream) |
| 1565 | fprintf(ctx->debug_stream, |
| 1566 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1567 | #endif |
| 1568 | |
| 1569 | /* SIGNING ---------------------------------------------------------------- */ |
| 1570 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 1571 | /* Copy headernames to signature struct */ |
| 1572 | sig->headernames = strdup(headernames->str); |
| 1573 | pdkim_strfree(headernames); |
| 1574 | |
| 1575 | /* Create signature header with b= omitted */ |
| 1576 | sig_hdr = pdkim_create_header(ctx->sig,0); |
| 1577 | } |
| 1578 | /* VERIFICATION ----------------------------------------------------------- */ |
| 1579 | else { |
| 1580 | sig_hdr = strdup(sig->rawsig_no_b_val); |
| 1581 | } |
| 1582 | /* ------------------------------------------------------------------------ */ |
| 1583 | |
| 1584 | if (sig_hdr == NULL) return PDKIM_ERR_OOM; |
| 1585 | |
| 1586 | /* Relax header if necessary */ |
| 1587 | if (sig->canon_headers == PDKIM_CANON_RELAXED) { |
| 1588 | char *relaxed_hdr = pdkim_relax_header(sig_hdr,0); |
| 1589 | free(sig_hdr); |
| 1590 | if (relaxed_hdr == NULL) return PDKIM_ERR_OOM; |
| 1591 | sig_hdr = relaxed_hdr; |
| 1592 | } |
| 1593 | |
| 1594 | #ifdef PDKIM_DEBUG |
| 1595 | if (ctx->debug_stream) { |
| 1596 | fprintf(ctx->debug_stream, |
| 1597 | "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n"); |
| 1598 | pdkim_quoteprint(ctx->debug_stream, sig_hdr, strlen(sig_hdr), 1); |
| 1599 | fprintf(ctx->debug_stream, |
| 1600 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1601 | } |
| 1602 | #endif |
| 1603 | |
| 1604 | /* Finalize header hash */ |
| 1605 | if (sig->algo == PDKIM_ALGO_RSA_SHA1) { |
| 1606 | sha1_update(&(sha1_headers),(unsigned char *)sig_hdr,strlen(sig_hdr)); |
| 1607 | sha1_finish(&(sha1_headers),(unsigned char *)headerhash); |
| 1608 | #ifdef PDKIM_DEBUG |
| 1609 | if (ctx->debug_stream) { |
| 1610 | fprintf(ctx->debug_stream, "PDKIM [%s] hh computed: ", sig->domain); |
| 1611 | pdkim_hexprint(ctx->debug_stream, headerhash, 20, 1); |
| 1612 | } |
| 1613 | #endif |
| 1614 | } |
| 1615 | else { |
| 1616 | sha2_update(&(sha2_headers),(unsigned char *)sig_hdr,strlen(sig_hdr)); |
| 1617 | sha2_finish(&(sha2_headers),(unsigned char *)headerhash); |
| 1618 | #ifdef PDKIM_DEBUG |
| 1619 | if (ctx->debug_stream) { |
| 1620 | fprintf(ctx->debug_stream, "PDKIM [%s] hh computed: ", sig->domain); |
| 1621 | pdkim_hexprint(ctx->debug_stream, headerhash, 32, 1); |
| 1622 | } |
| 1623 | #endif |
| 1624 | } |
| 1625 | |
| 1626 | free(sig_hdr); |
| 1627 | |
| 1628 | /* SIGNING ---------------------------------------------------------------- */ |
| 1629 | if (ctx->mode == PDKIM_MODE_SIGN) { |
| 1630 | rsa_context rsa; |
| 1631 | |
| 1632 | rsa_init(&rsa,RSA_PKCS_V15,0); |
| 1633 | |
| 1634 | /* Perform private key operation */ |
| 1635 | if (rsa_parse_key(&rsa, (unsigned char *)sig->rsa_privkey, |
| 1636 | strlen(sig->rsa_privkey), NULL, 0) != 0) { |
| 1637 | return PDKIM_ERR_RSA_PRIVKEY; |
| 1638 | } |
| 1639 | |
| 1640 | sig->sigdata_len = mpi_size(&(rsa.N)); |
| 1641 | sig->sigdata = malloc(sig->sigdata_len); |
| 1642 | if (sig->sigdata == NULL) return PDKIM_ERR_OOM; |
| 1643 | |
| 1644 | if (rsa_pkcs1_sign( &rsa, RSA_PRIVATE, |
| 1645 | ((sig->algo == PDKIM_ALGO_RSA_SHA1)? |
| 1646 | SIG_RSA_SHA1:SIG_RSA_SHA256), |
| 1647 | 0, |
| 1648 | (unsigned char *)headerhash, |
| 1649 | (unsigned char *)sig->sigdata ) != 0) { |
| 1650 | return PDKIM_ERR_RSA_SIGNING; |
| 1651 | } |
| 1652 | |
| 1653 | rsa_free(&rsa); |
| 1654 | |
| 1655 | #ifdef PDKIM_DEBUG |
| 1656 | if (ctx->debug_stream) { |
| 1657 | fprintf(ctx->debug_stream, "PDKIM [%s] b computed: ", |
| 1658 | sig->domain); |
| 1659 | pdkim_hexprint(ctx->debug_stream, sig->sigdata, sig->sigdata_len, 1); |
| 1660 | } |
| 1661 | #endif |
| 1662 | |
| 1663 | sig->signature_header = pdkim_create_header(ctx->sig,1); |
| 1664 | if (sig->signature_header == NULL) return PDKIM_ERR_OOM; |
| 1665 | } |
| 1666 | /* VERIFICATION ----------------------------------------------------------- */ |
| 1667 | else { |
| 1668 | rsa_context rsa; |
| 1669 | char *dns_txt_name, *dns_txt_reply; |
| 1670 | |
| 1671 | rsa_init(&rsa,RSA_PKCS_V15,0); |
| 1672 | |
| 1673 | dns_txt_name = malloc(PDKIM_DNS_TXT_MAX_NAMELEN); |
| 1674 | if (dns_txt_name == NULL) return PDKIM_ERR_OOM; |
| 1675 | dns_txt_reply = malloc(PDKIM_DNS_TXT_MAX_RECLEN); |
| 1676 | if (dns_txt_reply == NULL) { |
| 1677 | free(dns_txt_name); |
| 1678 | return PDKIM_ERR_OOM; |
| 1679 | } |
| 1680 | memset(dns_txt_reply,0,PDKIM_DNS_TXT_MAX_RECLEN); |
| 1681 | memset(dns_txt_name ,0,PDKIM_DNS_TXT_MAX_NAMELEN); |
| 1682 | |
| 1683 | if (snprintf(dns_txt_name,PDKIM_DNS_TXT_MAX_NAMELEN, |
| 1684 | "%s._domainkey.%s.", |
| 1685 | sig->selector,sig->domain) >= PDKIM_DNS_TXT_MAX_NAMELEN) { |
| 1686 | sig->verify_status = PDKIM_VERIFY_INVALID; |
| 1687 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_BUFFER_SIZE; |
| 1688 | goto NEXT_VERIFY; |
| 1689 | } |
| 1690 | |
| 1691 | if ((ctx->dns_txt_callback(dns_txt_name, dns_txt_reply) != PDKIM_OK) || |
| 1692 | (dns_txt_reply[0] == '\0')) { |
| 1693 | sig->verify_status = PDKIM_VERIFY_INVALID; |
| 1694 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE; |
| 1695 | goto NEXT_VERIFY; |
| 1696 | } |
| 1697 | |
| 1698 | #ifdef PDKIM_DEBUG |
| 1699 | if (ctx->debug_stream) { |
| 1700 | fprintf(ctx->debug_stream, |
| 1701 | "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
| 1702 | fprintf(ctx->debug_stream,"Raw record: "); |
| 1703 | pdkim_quoteprint(ctx->debug_stream, dns_txt_reply, strlen(dns_txt_reply), 1); |
| 1704 | } |
| 1705 | #endif |
| 1706 | |
| 1707 | sig->pubkey = pdkim_parse_pubkey_record(ctx,dns_txt_reply); |
| 1708 | if (sig->pubkey == NULL) { |
| 1709 | sig->verify_status = PDKIM_VERIFY_INVALID; |
| 1710 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING; |
| 1711 | #ifdef PDKIM_DEBUG |
| 1712 | if (ctx->debug_stream) { |
| 1713 | fprintf(ctx->debug_stream,"Error while parsing public key record\n"); |
| 1714 | fprintf(ctx->debug_stream, |
| 1715 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1716 | } |
| 1717 | #endif |
| 1718 | goto NEXT_VERIFY; |
| 1719 | } |
| 1720 | |
| 1721 | #ifdef PDKIM_DEBUG |
| 1722 | if (ctx->debug_stream) { |
| 1723 | fprintf(ctx->debug_stream, |
| 1724 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
| 1725 | } |
| 1726 | #endif |
| 1727 | |
| 1728 | if (rsa_parse_public_key(&rsa, |
| 1729 | (unsigned char *)sig->pubkey->key, |
| 1730 | sig->pubkey->key_len) != 0) { |
| 1731 | sig->verify_status = PDKIM_VERIFY_INVALID; |
| 1732 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_PARSING; |
| 1733 | goto NEXT_VERIFY; |
| 1734 | } |
| 1735 | |
| 1736 | /* Check the signature */ |
| 1737 | if (rsa_pkcs1_verify(&rsa, |
| 1738 | RSA_PUBLIC, |
| 1739 | ((sig->algo == PDKIM_ALGO_RSA_SHA1)? |
| 1740 | SIG_RSA_SHA1:SIG_RSA_SHA256), |
| 1741 | 0, |
| 1742 | (unsigned char *)headerhash, |
| 1743 | (unsigned char *)sig->sigdata) != 0) { |
| 1744 | sig->verify_status = PDKIM_VERIFY_FAIL; |
| 1745 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; |
| 1746 | goto NEXT_VERIFY; |
| 1747 | } |
| 1748 | |
| 1749 | /* We have a winner! (if bodydhash was correct earlier) */ |
| 1750 | if (sig->verify_status == PDKIM_VERIFY_NONE) { |
| 1751 | sig->verify_status = PDKIM_VERIFY_PASS; |
| 1752 | } |
| 1753 | |
| 1754 | NEXT_VERIFY: |
| 1755 | |
| 1756 | #ifdef PDKIM_DEBUG |
| 1757 | if (ctx->debug_stream) { |
| 1758 | fprintf(ctx->debug_stream, "PDKIM [%s] signature status: %s", |
| 1759 | sig->domain, pdkim_verify_status_str(sig->verify_status)); |
| 1760 | if (sig->verify_ext_status > 0) { |
| 1761 | fprintf(ctx->debug_stream, " (%s)\n", |
| 1762 | pdkim_verify_ext_status_str(sig->verify_ext_status)); |
| 1763 | } |
| 1764 | else { |
| 1765 | fprintf(ctx->debug_stream, "\n"); |
| 1766 | } |
| 1767 | } |
| 1768 | #endif |
| 1769 | |
| 1770 | rsa_free(&rsa); |
| 1771 | free(dns_txt_name); |
| 1772 | free(dns_txt_reply); |
| 1773 | } |
| 1774 | |
| 1775 | sig = sig->next; |
| 1776 | } |
| 1777 | |
| 1778 | /* If requested, set return pointer to signature(s) */ |
| 1779 | if (return_signatures != NULL) { |
| 1780 | *return_signatures = ctx->sig; |
| 1781 | } |
| 1782 | |
| 1783 | return PDKIM_OK; |
| 1784 | } |
| 1785 | |
| 1786 | |
| 1787 | /* -------------------------------------------------------------------------- */ |
| 1788 | DLLEXPORT pdkim_ctx *pdkim_init_verify(int input_mode, |
| 1789 | int(*dns_txt_callback)(char *, char *) |
| 1790 | ) { |
| 1791 | pdkim_ctx *ctx = malloc(sizeof(pdkim_ctx)); |
| 1792 | if (ctx == NULL) return NULL; |
| 1793 | memset(ctx,0,sizeof(pdkim_ctx)); |
| 1794 | |
| 1795 | ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN); |
| 1796 | if (ctx->linebuf == NULL) { |
| 1797 | free(ctx); |
| 1798 | return NULL; |
| 1799 | } |
| 1800 | |
| 1801 | ctx->mode = PDKIM_MODE_VERIFY; |
| 1802 | ctx->input_mode = input_mode; |
| 1803 | ctx->dns_txt_callback = dns_txt_callback; |
| 1804 | |
| 1805 | return ctx; |
| 1806 | } |
| 1807 | |
| 1808 | |
| 1809 | /* -------------------------------------------------------------------------- */ |
| 1810 | DLLEXPORT pdkim_ctx *pdkim_init_sign(int input_mode, |
| 1811 | char *domain, |
| 1812 | char *selector, |
| 1813 | char *rsa_privkey) { |
| 1814 | pdkim_ctx *ctx; |
| 1815 | pdkim_signature *sig; |
| 1816 | |
| 1817 | if (!domain || !selector || !rsa_privkey) return NULL; |
| 1818 | |
| 1819 | ctx = malloc(sizeof(pdkim_ctx)); |
| 1820 | if (ctx == NULL) return NULL; |
| 1821 | memset(ctx,0,sizeof(pdkim_ctx)); |
| 1822 | |
| 1823 | ctx->linebuf = malloc(PDKIM_MAX_BODY_LINE_LEN); |
| 1824 | if (ctx->linebuf == NULL) { |
| 1825 | free(ctx); |
| 1826 | return NULL; |
| 1827 | } |
| 1828 | |
| 1829 | sig = malloc(sizeof(pdkim_signature)); |
| 1830 | if (sig == NULL) { |
| 1831 | free(ctx->linebuf); |
| 1832 | free(ctx); |
| 1833 | return NULL; |
| 1834 | } |
| 1835 | memset(sig,0,sizeof(pdkim_signature)); |
| 1836 | sig->bodylength = -1; |
| 1837 | |
| 1838 | ctx->mode = PDKIM_MODE_SIGN; |
| 1839 | ctx->input_mode = input_mode; |
| 1840 | ctx->sig = sig; |
| 1841 | |
| 1842 | ctx->sig->domain = strdup(domain); |
| 1843 | ctx->sig->selector = strdup(selector); |
| 1844 | ctx->sig->rsa_privkey = strdup(rsa_privkey); |
| 1845 | |
| 1846 | if (!ctx->sig->domain || !ctx->sig->selector || !ctx->sig->rsa_privkey) { |
| 1847 | pdkim_free_ctx(ctx); |
| 1848 | return NULL; |
| 1849 | } |
| 1850 | |
| 1851 | ctx->sig->sha1_body = malloc(sizeof(sha1_context)); |
| 1852 | if (ctx->sig->sha1_body == NULL) { |
| 1853 | pdkim_free_ctx(ctx); |
| 1854 | return NULL; |
| 1855 | } |
| 1856 | sha1_starts(ctx->sig->sha1_body); |
| 1857 | |
| 1858 | ctx->sig->sha2_body = malloc(sizeof(sha2_context)); |
| 1859 | if (ctx->sig->sha2_body == NULL) { |
| 1860 | pdkim_free_ctx(ctx); |
| 1861 | return NULL; |
| 1862 | } |
| 1863 | sha2_starts(ctx->sig->sha2_body,0); |
| 1864 | |
| 1865 | return ctx; |
| 1866 | } |
| 1867 | |
| 1868 | #ifdef PDKIM_DEBUG |
| 1869 | /* -------------------------------------------------------------------------- */ |
| 1870 | DLLEXPORT void pdkim_set_debug_stream(pdkim_ctx *ctx, |
| 1871 | FILE *debug_stream) { |
| 1872 | ctx->debug_stream = debug_stream; |
| 1873 | } |
| 1874 | #endif |
| 1875 | |
| 1876 | /* -------------------------------------------------------------------------- */ |
| 1877 | DLLEXPORT int pdkim_set_optional(pdkim_ctx *ctx, |
| 1878 | char *sign_headers, |
| 1879 | char *identity, |
| 1880 | int canon_headers, |
| 1881 | int canon_body, |
| 1882 | long bodylength, |
| 1883 | int algo, |
| 1884 | unsigned long created, |
| 1885 | unsigned long expires) { |
| 1886 | |
| 1887 | if (identity != NULL) { |
| 1888 | ctx->sig->identity = strdup(identity); |
| 1889 | if (ctx->sig->identity == NULL) return PDKIM_ERR_OOM; |
| 1890 | } |
| 1891 | |
| 1892 | if (sign_headers != NULL) { |
| 1893 | ctx->sig->sign_headers = strdup(sign_headers); |
| 1894 | if (ctx->sig->sign_headers == NULL) return PDKIM_ERR_OOM; |
| 1895 | } |
| 1896 | |
| 1897 | ctx->sig->canon_headers = canon_headers; |
| 1898 | ctx->sig->canon_body = canon_body; |
| 1899 | ctx->sig->bodylength = bodylength; |
| 1900 | ctx->sig->algo = algo; |
| 1901 | ctx->sig->created = created; |
| 1902 | ctx->sig->expires = expires; |
| 1903 | |
| 1904 | return PDKIM_OK; |
| 1905 | } |