Commit | Line | Data |
---|---|---|
80a47a2c TK |
1 | /* |
2 | * PDKIM - a RFC4871 (DKIM) implementation | |
3 | * | |
f444c2c7 JH |
4 | * Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net> |
5 | * Copyright (C) 2016 Jeremy Harris <jgh@exim.org> | |
80a47a2c TK |
6 | * |
7 | * http://duncanthrax.net/pdkim/ | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; if not, write to the Free Software Foundation, Inc., | |
21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
22 | */ | |
23 | ||
0d04a285 | 24 | #include "../exim.h" |
80a47a2c | 25 | |
f444c2c7 JH |
26 | |
27 | #ifndef DISABLE_DKIM /* entire file */ | |
28 | ||
29 | #ifndef SUPPORT_TLS | |
30 | # error Need SUPPORT_TLS for DKIM | |
31 | #endif | |
32 | ||
cb224393 | 33 | #include "crypt_ver.h" |
f444c2c7 | 34 | |
cb224393 JH |
35 | #ifdef RSA_OPENSSL |
36 | # include <openssl/rsa.h> | |
37 | # include <openssl/ssl.h> | |
38 | # include <openssl/err.h> | |
39 | #elif defined(RSA_GNUTLS) | |
f444c2c7 JH |
40 | # include <gnutls/gnutls.h> |
41 | # include <gnutls/x509.h> | |
f444c2c7 JH |
42 | #endif |
43 | ||
44 | #include "pdkim.h" | |
2592e6c0 | 45 | #include "rsa.h" |
80a47a2c TK |
46 | |
47 | #define PDKIM_SIGNATURE_VERSION "1" | |
e2e3255a | 48 | #define PDKIM_PUB_RECORD_VERSION US "DKIM1" |
80a47a2c TK |
49 | |
50 | #define PDKIM_MAX_HEADER_LEN 65536 | |
51 | #define PDKIM_MAX_HEADERS 512 | |
52 | #define PDKIM_MAX_BODY_LINE_LEN 16384 | |
53 | #define PDKIM_DNS_TXT_MAX_NAMELEN 1024 | |
54 | #define PDKIM_DEFAULT_SIGN_HEADERS "From:Sender:Reply-To:Subject:Date:"\ | |
55 | "Message-ID:To:Cc:MIME-Version:Content-Type:"\ | |
56 | "Content-Transfer-Encoding:Content-ID:"\ | |
57 | "Content-Description:Resent-Date:Resent-From:"\ | |
58 | "Resent-Sender:Resent-To:Resent-Cc:"\ | |
59 | "Resent-Message-ID:In-Reply-To:References:"\ | |
60 | "List-Id:List-Help:List-Unsubscribe:"\ | |
61 | "List-Subscribe:List-Post:List-Owner:List-Archive" | |
62 | ||
63 | /* -------------------------------------------------------------------------- */ | |
64 | struct pdkim_stringlist { | |
e2e3255a JH |
65 | uschar * value; |
66 | int tag; | |
67 | void * next; | |
80a47a2c TK |
68 | }; |
69 | ||
80a47a2c TK |
70 | /* -------------------------------------------------------------------------- */ |
71 | /* A bunch of list constants */ | |
e2e3255a JH |
72 | const uschar * pdkim_querymethods[] = { |
73 | US"dns/txt", | |
80a47a2c TK |
74 | NULL |
75 | }; | |
e2e3255a JH |
76 | const uschar * pdkim_algos[] = { |
77 | US"rsa-sha256", | |
78 | US"rsa-sha1", | |
80a47a2c TK |
79 | NULL |
80 | }; | |
e2e3255a JH |
81 | const uschar * pdkim_canons[] = { |
82 | US"simple", | |
83 | US"relaxed", | |
80a47a2c TK |
84 | NULL |
85 | }; | |
e2e3255a JH |
86 | const uschar * pdkim_hashes[] = { |
87 | US"sha256", | |
88 | US"sha1", | |
80a47a2c TK |
89 | NULL |
90 | }; | |
e2e3255a JH |
91 | const uschar * pdkim_keytypes[] = { |
92 | US"rsa", | |
80a47a2c TK |
93 | NULL |
94 | }; | |
95 | ||
96 | typedef struct pdkim_combined_canon_entry { | |
e2e3255a | 97 | const uschar * str; |
80a47a2c TK |
98 | int canon_headers; |
99 | int canon_body; | |
100 | } pdkim_combined_canon_entry; | |
f444c2c7 | 101 | |
80a47a2c | 102 | pdkim_combined_canon_entry pdkim_combined_canons[] = { |
e2e3255a JH |
103 | { US"simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, |
104 | { US"simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED }, | |
105 | { US"relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, | |
106 | { US"relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED }, | |
107 | { US"simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, | |
108 | { US"relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, | |
109 | { NULL, 0, 0 } | |
80a47a2c TK |
110 | }; |
111 | ||
112 | ||
f444c2c7 JH |
113 | /* -------------------------------------------------------------------------- */ |
114 | ||
115 | const char * | |
116 | pdkim_verify_status_str(int status) | |
117 | { | |
ff7ddfd7 TK |
118 | switch(status) { |
119 | case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE"; | |
120 | case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID"; | |
121 | case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL"; | |
122 | case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS"; | |
123 | default: return "PDKIM_VERIFY_UNKNOWN"; | |
124 | } | |
125 | } | |
f444c2c7 JH |
126 | |
127 | const char * | |
128 | pdkim_verify_ext_status_str(int ext_status) | |
129 | { | |
ff7ddfd7 TK |
130 | switch(ext_status) { |
131 | case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY"; | |
132 | case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE"; | |
133 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE"; | |
134 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE"; | |
df3def24 JH |
135 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD"; |
136 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT"; | |
ff7ddfd7 TK |
137 | default: return "PDKIM_VERIFY_UNKNOWN"; |
138 | } | |
139 | } | |
140 | ||
141 | ||
80a47a2c TK |
142 | /* -------------------------------------------------------------------------- */ |
143 | /* Print debugging functions */ | |
2592e6c0 | 144 | static void |
b78006ac | 145 | pdkim_quoteprint(const uschar *data, int len) |
3045f050 JH |
146 | { |
147 | int i; | |
0d04a285 | 148 | for (i = 0; i < len; i++) |
3045f050 | 149 | { |
b78006ac | 150 | const int c = data[i]; |
3045f050 JH |
151 | switch (c) |
152 | { | |
0d04a285 JH |
153 | case ' ' : debug_printf("{SP}"); break; |
154 | case '\t': debug_printf("{TB}"); break; | |
155 | case '\r': debug_printf("{CR}"); break; | |
156 | case '\n': debug_printf("{LF}"); break; | |
157 | case '{' : debug_printf("{BO}"); break; | |
158 | case '}' : debug_printf("{BC}"); break; | |
3045f050 JH |
159 | default: |
160 | if ( (c < 32) || (c > 127) ) | |
0d04a285 | 161 | debug_printf("{%02x}", c); |
3045f050 | 162 | else |
0d04a285 | 163 | debug_printf("%c", c); |
80a47a2c TK |
164 | break; |
165 | } | |
166 | } | |
2592e6c0 | 167 | debug_printf("\n"); |
80a47a2c | 168 | } |
80a47a2c | 169 | |
2592e6c0 | 170 | static void |
b78006ac | 171 | pdkim_hexprint(const uschar *data, int len) |
3045f050 JH |
172 | { |
173 | int i; | |
b78006ac | 174 | for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]); |
2592e6c0 | 175 | debug_printf("\n"); |
80a47a2c | 176 | } |
80a47a2c TK |
177 | |
178 | ||
f444c2c7 | 179 | |
f444c2c7 | 180 | static pdkim_stringlist * |
ca9cb170 | 181 | pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str) |
3045f050 | 182 | { |
ca9cb170 | 183 | pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist)); |
3045f050 | 184 | |
abe1010c | 185 | memset(new_entry, 0, sizeof(pdkim_stringlist)); |
ca9cb170 | 186 | new_entry->value = string_copy(str); |
ab9152ff JH |
187 | if (base) new_entry->next = base; |
188 | return new_entry; | |
6ab02e3f | 189 | } |
80a47a2c TK |
190 | |
191 | ||
8ef02a06 JH |
192 | |
193 | /* Trim whitespace fore & aft */ | |
194 | ||
ca9cb170 JH |
195 | static void |
196 | pdkim_strtrim(uschar * str) | |
3045f050 | 197 | { |
ca9cb170 JH |
198 | uschar * p = str; |
199 | uschar * q = str; | |
8ef02a06 JH |
200 | while (*p == '\t' || *p == ' ') p++; /* skip whitespace */ |
201 | while (*p) {*q = *p; q++; p++;} /* dump the leading whitespace */ | |
3045f050 | 202 | *q = '\0'; |
ca9cb170 | 203 | while (q != str && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) ) |
8ef02a06 | 204 | { /* dump trailing whitespace */ |
80a47a2c | 205 | *q = '\0'; |
3045f050 | 206 | q--; |
80a47a2c | 207 | } |
8ef02a06 JH |
208 | } |
209 | ||
210 | ||
80a47a2c | 211 | |
80a47a2c | 212 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
213 | |
214 | DLLEXPORT void | |
215 | pdkim_free_ctx(pdkim_ctx *ctx) | |
216 | { | |
6ab02e3f | 217 | } |
80a47a2c TK |
218 | |
219 | ||
220 | /* -------------------------------------------------------------------------- */ | |
221 | /* Matches the name of the passed raw "header" against | |
8ef02a06 JH |
222 | the passed colon-separated "tick", and invalidates |
223 | the entry in tick. Returns OK or fail-code */ | |
224 | /*XXX might be safer done using a pdkim_stringlist for "tick" */ | |
3045f050 | 225 | |
f444c2c7 | 226 | static int |
e2e3255a | 227 | header_name_match(const uschar * header, uschar * tick) |
3045f050 | 228 | { |
ca9cb170 JH |
229 | uschar * hname; |
230 | uschar * lcopy; | |
231 | uschar * p; | |
232 | uschar * q; | |
233 | uschar * hcolon = Ustrchr(header, ':'); /* Get header name */ | |
3045f050 | 234 | |
ca9cb170 JH |
235 | if (!hcolon) |
236 | return PDKIM_FAIL; /* This isn't a header */ | |
3045f050 | 237 | |
ca9cb170 JH |
238 | /* if we had strncmpic() we wouldn't need this copy */ |
239 | hname = string_copyn(header, hcolon-header); | |
3045f050 JH |
240 | |
241 | /* Copy tick-off list locally, so we can punch zeroes into it */ | |
ca9cb170 JH |
242 | p = lcopy = string_copy(tick); |
243 | ||
244 | for (q = Ustrchr(p, ':'); q; q = Ustrchr(p, ':')) | |
3045f050 JH |
245 | { |
246 | *q = '\0'; | |
ca9cb170 JH |
247 | if (strcmpic(p, hname) == 0) |
248 | goto found; | |
80a47a2c | 249 | |
3045f050 | 250 | p = q+1; |
80a47a2c TK |
251 | } |
252 | ||
ca9cb170 JH |
253 | if (strcmpic(p, hname) == 0) |
254 | goto found; | |
255 | ||
256 | return PDKIM_FAIL; | |
257 | ||
258 | found: | |
3045f050 | 259 | /* Invalidate header name instance in tick-off list */ |
8ef02a06 | 260 | tick[p-lcopy] = '_'; |
ca9cb170 | 261 | return PDKIM_OK; |
80a47a2c TK |
262 | } |
263 | ||
264 | ||
265 | /* -------------------------------------------------------------------------- */ | |
ca9cb170 | 266 | /* Performs "relaxed" canonicalization of a header. */ |
3045f050 | 267 | |
ca9cb170 JH |
268 | static uschar * |
269 | pdkim_relax_header(const uschar * header, int crlf) | |
3045f050 JH |
270 | { |
271 | BOOL past_field_name = FALSE; | |
272 | BOOL seen_wsp = FALSE; | |
ca9cb170 JH |
273 | const uschar * p; |
274 | uschar * relaxed = store_get(Ustrlen(header)+3); | |
275 | uschar * q = relaxed; | |
3045f050 | 276 | |
ca9cb170 | 277 | for (p = header; *p; p++) |
3045f050 | 278 | { |
ca9cb170 | 279 | uschar c = *p; |
3045f050 JH |
280 | /* Ignore CR & LF */ |
281 | if (c == '\r' || c == '\n') | |
282 | continue; | |
283 | if (c == '\t' || c == ' ') | |
284 | { | |
285 | if (seen_wsp) | |
80a47a2c | 286 | continue; |
3045f050 JH |
287 | c = ' '; /* Turns WSP into SP */ |
288 | seen_wsp = TRUE; | |
80a47a2c | 289 | } |
3045f050 JH |
290 | else |
291 | if (!past_field_name && c == ':') | |
292 | { | |
293 | if (seen_wsp) q--; /* This removes WSP before the colon */ | |
294 | seen_wsp = TRUE; /* This removes WSP after the colon */ | |
295 | past_field_name = TRUE; | |
80a47a2c | 296 | } |
3045f050 JH |
297 | else |
298 | seen_wsp = FALSE; | |
299 | ||
300 | /* Lowercase header name */ | |
301 | if (!past_field_name) c = tolower(c); | |
302 | *q++ = c; | |
80a47a2c | 303 | } |
3045f050 JH |
304 | |
305 | if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */ | |
3045f050 | 306 | |
ca9cb170 JH |
307 | if (crlf) { *q++ = '\r'; *q++ = '\n'; } |
308 | *q = '\0'; | |
3045f050 | 309 | return relaxed; |
6ab02e3f | 310 | } |
80a47a2c TK |
311 | |
312 | ||
313 | /* -------------------------------------------------------------------------- */ | |
314 | #define PDKIM_QP_ERROR_DECODE -1 | |
3045f050 | 315 | |
e2e3255a JH |
316 | static uschar * |
317 | pdkim_decode_qp_char(uschar *qp_p, int *c) | |
3045f050 | 318 | { |
e2e3255a | 319 | uschar *initial_pos = qp_p; |
3045f050 JH |
320 | |
321 | /* Advance one char */ | |
322 | qp_p++; | |
323 | ||
324 | /* Check for two hex digits and decode them */ | |
325 | if (isxdigit(*qp_p) && isxdigit(qp_p[1])) | |
326 | { | |
327 | /* Do hex conversion */ | |
328 | *c = (isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10) << 4; | |
a5840e10 | 329 | *c |= isdigit(qp_p[1]) ? qp_p[1] - '0' : toupper(qp_p[1]) - 'A' + 10; |
3045f050 | 330 | return qp_p + 2; |
6ab02e3f | 331 | } |
80a47a2c | 332 | |
3045f050 JH |
333 | /* Illegal char here */ |
334 | *c = PDKIM_QP_ERROR_DECODE; | |
335 | return initial_pos; | |
80a47a2c TK |
336 | } |
337 | ||
338 | ||
339 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 340 | |
e2e3255a | 341 | static uschar * |
ca9cb170 | 342 | pdkim_decode_qp(uschar * str) |
3045f050 JH |
343 | { |
344 | int nchar = 0; | |
ca9cb170 JH |
345 | uschar * q; |
346 | uschar * p = str; | |
347 | uschar * n = store_get(Ustrlen(str)+1); | |
3045f050 JH |
348 | |
349 | *n = '\0'; | |
350 | q = n; | |
ca9cb170 | 351 | while (*p) |
3045f050 JH |
352 | { |
353 | if (*p == '=') | |
354 | { | |
355 | p = pdkim_decode_qp_char(p, &nchar); | |
356 | if (nchar >= 0) | |
357 | { | |
358 | *q++ = nchar; | |
359 | continue; | |
80a47a2c TK |
360 | } |
361 | } | |
3045f050 JH |
362 | else |
363 | *q++ = *p; | |
364 | p++; | |
80a47a2c | 365 | } |
3045f050 JH |
366 | *q = '\0'; |
367 | return n; | |
80a47a2c TK |
368 | } |
369 | ||
370 | ||
371 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 372 | |
2592e6c0 JH |
373 | static void |
374 | pdkim_decode_base64(uschar *str, blob * b) | |
3045f050 | 375 | { |
2592e6c0 | 376 | int dlen; |
2592e6c0 JH |
377 | dlen = b64decode(str, &b->data); |
378 | if (dlen < 0) b->data = NULL; | |
379 | b->len = dlen; | |
80a47a2c TK |
380 | } |
381 | ||
ca9cb170 | 382 | static uschar * |
2592e6c0 | 383 | pdkim_encode_base64(blob * b) |
3045f050 | 384 | { |
ca9cb170 | 385 | return b64encode(b->data, b->len); |
80a47a2c TK |
386 | } |
387 | ||
388 | ||
389 | /* -------------------------------------------------------------------------- */ | |
390 | #define PDKIM_HDR_LIMBO 0 | |
391 | #define PDKIM_HDR_TAG 1 | |
392 | #define PDKIM_HDR_VALUE 2 | |
3045f050 | 393 | |
f444c2c7 | 394 | static pdkim_signature * |
ca9cb170 | 395 | pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr) |
3045f050 JH |
396 | { |
397 | pdkim_signature *sig ; | |
ca9cb170 JH |
398 | uschar *p, *q; |
399 | uschar * cur_tag = NULL; int ts = 0, tl = 0; | |
400 | uschar * cur_val = NULL; int vs = 0, vl = 0; | |
3045f050 JH |
401 | BOOL past_hname = FALSE; |
402 | BOOL in_b_val = FALSE; | |
403 | int where = PDKIM_HDR_LIMBO; | |
404 | int i; | |
405 | ||
ca9cb170 | 406 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 407 | memset(sig, 0, sizeof(pdkim_signature)); |
3045f050 JH |
408 | sig->bodylength = -1; |
409 | ||
ca9cb170 | 410 | q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1); |
80a47a2c | 411 | |
3045f050 JH |
412 | for (p = raw_hdr; ; p++) |
413 | { | |
414 | char c = *p; | |
80a47a2c | 415 | |
3045f050 JH |
416 | /* Ignore FWS */ |
417 | if (c == '\r' || c == '\n') | |
418 | goto NEXT_CHAR; | |
80a47a2c | 419 | |
3045f050 JH |
420 | /* Fast-forward through header name */ |
421 | if (!past_hname) | |
422 | { | |
423 | if (c == ':') past_hname = TRUE; | |
424 | goto NEXT_CHAR; | |
80a47a2c TK |
425 | } |
426 | ||
3045f050 JH |
427 | if (where == PDKIM_HDR_LIMBO) |
428 | { | |
429 | /* In limbo, just wait for a tag-char to appear */ | |
430 | if (!(c >= 'a' && c <= 'z')) | |
431 | goto NEXT_CHAR; | |
80a47a2c | 432 | |
3045f050 | 433 | where = PDKIM_HDR_TAG; |
80a47a2c TK |
434 | } |
435 | ||
3045f050 JH |
436 | if (where == PDKIM_HDR_TAG) |
437 | { | |
3045f050 | 438 | if (c >= 'a' && c <= 'z') |
c2f669a4 | 439 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); |
80a47a2c | 440 | |
3045f050 JH |
441 | if (c == '=') |
442 | { | |
ca9cb170 JH |
443 | cur_tag[tl] = '\0'; |
444 | if (Ustrcmp(cur_tag, "b") == 0) | |
3045f050 | 445 | { |
ca9cb170 | 446 | *q++ = '='; |
3045f050 JH |
447 | in_b_val = TRUE; |
448 | } | |
449 | where = PDKIM_HDR_VALUE; | |
450 | goto NEXT_CHAR; | |
80a47a2c TK |
451 | } |
452 | } | |
453 | ||
3045f050 JH |
454 | if (where == PDKIM_HDR_VALUE) |
455 | { | |
3045f050 JH |
456 | if (c == '\r' || c == '\n' || c == ' ' || c == '\t') |
457 | goto NEXT_CHAR; | |
458 | ||
459 | if (c == ';' || c == '\0') | |
460 | { | |
ca9cb170 | 461 | if (tl && vl) |
3045f050 | 462 | { |
ca9cb170 | 463 | cur_val[vl] = '\0'; |
3045f050 JH |
464 | pdkim_strtrim(cur_val); |
465 | ||
ca9cb170 | 466 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); |
3045f050 | 467 | |
ca9cb170 | 468 | switch (*cur_tag) |
3045f050 JH |
469 | { |
470 | case 'b': | |
ca9cb170 JH |
471 | if (cur_tag[1] == 'h') |
472 | pdkim_decode_base64(cur_val, &sig->bodyhash); | |
3045f050 | 473 | else |
ca9cb170 | 474 | pdkim_decode_base64(cur_val, &sig->sigdata); |
3045f050 JH |
475 | break; |
476 | case 'v': | |
477 | /* We only support version 1, and that is currently the | |
478 | only version there is. */ | |
ca9cb170 | 479 | if (Ustrcmp(cur_val, PDKIM_SIGNATURE_VERSION) == 0) |
3045f050 JH |
480 | sig->version = 1; |
481 | break; | |
482 | case 'a': | |
483 | for (i = 0; pdkim_algos[i]; i++) | |
ca9cb170 | 484 | if (Ustrcmp(cur_val, pdkim_algos[i]) == 0) |
3045f050 JH |
485 | { |
486 | sig->algo = i; | |
487 | break; | |
488 | } | |
489 | break; | |
490 | case 'c': | |
491 | for (i = 0; pdkim_combined_canons[i].str; i++) | |
ca9cb170 | 492 | if (Ustrcmp(cur_val, pdkim_combined_canons[i].str) == 0) |
3045f050 JH |
493 | { |
494 | sig->canon_headers = pdkim_combined_canons[i].canon_headers; | |
495 | sig->canon_body = pdkim_combined_canons[i].canon_body; | |
496 | break; | |
497 | } | |
498 | break; | |
499 | case 'q': | |
500 | for (i = 0; pdkim_querymethods[i]; i++) | |
ca9cb170 | 501 | if (Ustrcmp(cur_val, pdkim_querymethods[i]) == 0) |
3045f050 JH |
502 | { |
503 | sig->querymethod = i; | |
504 | break; | |
505 | } | |
506 | break; | |
507 | case 's': | |
ca9cb170 | 508 | sig->selector = string_copy(cur_val); break; |
3045f050 | 509 | case 'd': |
ca9cb170 | 510 | sig->domain = string_copy(cur_val); break; |
3045f050 | 511 | case 'i': |
ca9cb170 | 512 | sig->identity = pdkim_decode_qp(cur_val); break; |
3045f050 | 513 | case 't': |
ca9cb170 | 514 | sig->created = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 515 | case 'x': |
ca9cb170 | 516 | sig->expires = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 517 | case 'l': |
ca9cb170 | 518 | sig->bodylength = strtol(CS cur_val, NULL, 10); break; |
3045f050 | 519 | case 'h': |
ca9cb170 | 520 | sig->headernames = string_copy(cur_val); break; |
3045f050 | 521 | case 'z': |
ca9cb170 | 522 | sig->copiedheaders = pdkim_decode_qp(cur_val); break; |
3045f050 | 523 | default: |
0d04a285 | 524 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); |
3045f050 JH |
525 | break; |
526 | } | |
527 | } | |
ca9cb170 JH |
528 | tl = 0; |
529 | vl = 0; | |
3045f050 JH |
530 | in_b_val = FALSE; |
531 | where = PDKIM_HDR_LIMBO; | |
80a47a2c | 532 | } |
3045f050 | 533 | else |
c2f669a4 | 534 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); |
80a47a2c TK |
535 | } |
536 | ||
3045f050 JH |
537 | NEXT_CHAR: |
538 | if (c == '\0') | |
539 | break; | |
80a47a2c | 540 | |
3045f050 JH |
541 | if (!in_b_val) |
542 | *q++ = c; | |
80a47a2c TK |
543 | } |
544 | ||
3045f050 | 545 | /* Make sure the most important bits are there. */ |
ca9cb170 | 546 | if (!sig->version) |
3045f050 | 547 | return NULL; |
80a47a2c | 548 | |
3045f050 JH |
549 | *q = '\0'; |
550 | /* Chomp raw header. The final newline must not be added to the signature. */ | |
37f3dc43 JH |
551 | while (--q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n')) |
552 | *q = '\0'; | |
80a47a2c | 553 | |
0d04a285 | 554 | DEBUG(D_acl) |
3045f050 | 555 | { |
0d04a285 | 556 | debug_printf( |
3045f050 | 557 | "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 558 | pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val)); |
0d04a285 | 559 | debug_printf( |
b78006ac | 560 | "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sigdata.len*8); |
0d04a285 | 561 | debug_printf( |
3045f050 | 562 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 563 | } |
80a47a2c | 564 | |
1ed59855 | 565 | exim_sha_init(&sig->body_hash, sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); |
3045f050 | 566 | return sig; |
80a47a2c TK |
567 | } |
568 | ||
569 | ||
570 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 571 | |
f444c2c7 | 572 | static pdkim_pubkey * |
e2e3255a | 573 | pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record) |
3045f050 JH |
574 | { |
575 | pdkim_pubkey *pub; | |
e2e3255a | 576 | const uschar *p; |
ca9cb170 JH |
577 | uschar * cur_tag = NULL; int ts = 0, tl = 0; |
578 | uschar * cur_val = NULL; int vs = 0, vl = 0; | |
3045f050 | 579 | int where = PDKIM_HDR_LIMBO; |
80a47a2c | 580 | |
ca9cb170 | 581 | pub = store_get(sizeof(pdkim_pubkey)); |
abe1010c | 582 | memset(pub, 0, sizeof(pdkim_pubkey)); |
80a47a2c | 583 | |
3045f050 JH |
584 | for (p = raw_record; ; p++) |
585 | { | |
586 | char c = *p; | |
80a47a2c | 587 | |
3045f050 JH |
588 | /* Ignore FWS */ |
589 | if (c == '\r' || c == '\n') | |
590 | goto NEXT_CHAR; | |
80a47a2c | 591 | |
3045f050 JH |
592 | if (where == PDKIM_HDR_LIMBO) |
593 | { | |
594 | /* In limbo, just wait for a tag-char to appear */ | |
595 | if (!(c >= 'a' && c <= 'z')) | |
596 | goto NEXT_CHAR; | |
80a47a2c | 597 | |
3045f050 | 598 | where = PDKIM_HDR_TAG; |
80a47a2c TK |
599 | } |
600 | ||
3045f050 JH |
601 | if (where == PDKIM_HDR_TAG) |
602 | { | |
3045f050 | 603 | if (c >= 'a' && c <= 'z') |
c2f669a4 | 604 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); |
80a47a2c | 605 | |
3045f050 JH |
606 | if (c == '=') |
607 | { | |
ca9cb170 | 608 | cur_tag[tl] = '\0'; |
3045f050 JH |
609 | where = PDKIM_HDR_VALUE; |
610 | goto NEXT_CHAR; | |
80a47a2c TK |
611 | } |
612 | } | |
613 | ||
3045f050 JH |
614 | if (where == PDKIM_HDR_VALUE) |
615 | { | |
3045f050 JH |
616 | if (c == ';' || c == '\0') |
617 | { | |
ca9cb170 | 618 | if (tl && vl) |
3045f050 | 619 | { |
ca9cb170 | 620 | cur_val[vl] = '\0'; |
3045f050 | 621 | pdkim_strtrim(cur_val); |
ca9cb170 | 622 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); |
3045f050 | 623 | |
ca9cb170 | 624 | switch (cur_tag[0]) |
3045f050 JH |
625 | { |
626 | case 'v': | |
627 | /* This tag isn't evaluated because: | |
628 | - We only support version DKIM1. | |
629 | - Which is the default for this value (set below) | |
630 | - Other versions are currently not specified. */ | |
631 | break; | |
632 | case 'h': | |
ca9cb170 JH |
633 | case 'k': |
634 | pub->hashes = string_copy(cur_val); break; | |
3045f050 | 635 | case 'g': |
ca9cb170 | 636 | pub->granularity = string_copy(cur_val); break; |
3045f050 | 637 | case 'n': |
ca9cb170 | 638 | pub->notes = pdkim_decode_qp(cur_val); break; |
3045f050 | 639 | case 'p': |
ca9cb170 | 640 | pdkim_decode_base64(US cur_val, &pub->key); |
2592e6c0 | 641 | break; |
3045f050 | 642 | case 's': |
ca9cb170 | 643 | pub->srvtype = string_copy(cur_val); break; |
3045f050 | 644 | case 't': |
e2e3255a JH |
645 | if (Ustrchr(cur_val, 'y') != NULL) pub->testing = 1; |
646 | if (Ustrchr(cur_val, 's') != NULL) pub->no_subdomaining = 1; | |
3045f050 JH |
647 | break; |
648 | default: | |
0d04a285 | 649 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); |
3045f050 JH |
650 | break; |
651 | } | |
652 | } | |
ca9cb170 JH |
653 | tl = 0; |
654 | vl = 0; | |
3045f050 | 655 | where = PDKIM_HDR_LIMBO; |
80a47a2c | 656 | } |
3045f050 | 657 | else |
c2f669a4 | 658 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); |
80a47a2c TK |
659 | } |
660 | ||
3045f050 JH |
661 | NEXT_CHAR: |
662 | if (c == '\0') break; | |
80a47a2c TK |
663 | } |
664 | ||
3045f050 | 665 | /* Set fallback defaults */ |
ca9cb170 JH |
666 | if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION); |
667 | if (!pub->granularity) pub->granularity = string_copy(US"*"); | |
e2e3255a | 668 | if (!pub->keytype ) pub->keytype = string_copy(US"rsa"); |
ca9cb170 | 669 | if (!pub->srvtype ) pub->srvtype = string_copy(US"*"); |
80a47a2c | 670 | |
3045f050 | 671 | /* p= is required */ |
2592e6c0 | 672 | if (pub->key.data) |
80a47a2c | 673 | return pub; |
3045f050 | 674 | |
3045f050 | 675 | return NULL; |
80a47a2c TK |
676 | } |
677 | ||
678 | ||
679 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 680 | |
f444c2c7 | 681 | static int |
3045f050 JH |
682 | pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len) |
683 | { | |
684 | pdkim_signature *sig = ctx->sig; | |
685 | /* Cache relaxed version of data */ | |
b78006ac JH |
686 | uschar *relaxed_data = NULL; |
687 | int relaxed_len = 0; | |
3045f050 JH |
688 | |
689 | /* Traverse all signatures, updating their hashes. */ | |
690 | while (sig) | |
691 | { | |
692 | /* Defaults to simple canon (no further treatment necessary) */ | |
b78006ac JH |
693 | const uschar *canon_data = CUS data; |
694 | int canon_len = len; | |
3045f050 JH |
695 | |
696 | if (sig->canon_body == PDKIM_CANON_RELAXED) | |
697 | { | |
698 | /* Relax the line if not done already */ | |
699 | if (!relaxed_data) | |
700 | { | |
701 | BOOL seen_wsp = FALSE; | |
702 | const char *p; | |
703 | int q = 0; | |
704 | ||
ca9cb170 | 705 | relaxed_data = store_get(len+1); |
3045f050 JH |
706 | |
707 | for (p = data; *p; p++) | |
708 | { | |
709 | char c = *p; | |
710 | if (c == '\r') | |
711 | { | |
712 | if (q > 0 && relaxed_data[q-1] == ' ') | |
713 | q--; | |
714 | } | |
715 | else if (c == '\t' || c == ' ') | |
716 | { | |
717 | c = ' '; /* Turns WSP into SP */ | |
718 | if (seen_wsp) | |
719 | continue; | |
720 | seen_wsp = TRUE; | |
721 | } | |
722 | else | |
723 | seen_wsp = FALSE; | |
724 | relaxed_data[q++] = c; | |
725 | } | |
726 | relaxed_data[q] = '\0'; | |
727 | relaxed_len = q; | |
80a47a2c | 728 | } |
3045f050 JH |
729 | canon_data = relaxed_data; |
730 | canon_len = relaxed_len; | |
80a47a2c TK |
731 | } |
732 | ||
3045f050 JH |
733 | /* Make sure we don't exceed the to-be-signed body length */ |
734 | if ( sig->bodylength >= 0 | |
735 | && sig->signed_body_bytes + (unsigned long)canon_len > sig->bodylength | |
736 | ) | |
737 | canon_len = sig->bodylength - sig->signed_body_bytes; | |
80a47a2c | 738 | |
3045f050 JH |
739 | if (canon_len > 0) |
740 | { | |
e2e3255a | 741 | exim_sha_update(&sig->body_hash, CUS canon_data, canon_len); |
3045f050 | 742 | sig->signed_body_bytes += canon_len; |
2592e6c0 | 743 | DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len); |
80a47a2c TK |
744 | } |
745 | ||
3045f050 | 746 | sig = sig->next; |
80a47a2c TK |
747 | } |
748 | ||
3045f050 | 749 | return PDKIM_OK; |
6ab02e3f | 750 | } |
80a47a2c TK |
751 | |
752 | ||
753 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 754 | |
ca9cb170 | 755 | static void |
3045f050 JH |
756 | pdkim_finish_bodyhash(pdkim_ctx *ctx) |
757 | { | |
f4d091fb | 758 | pdkim_signature *sig; |
80a47a2c | 759 | |
3045f050 | 760 | /* Traverse all signatures */ |
f4d091fb | 761 | for (sig = ctx->sig; sig; sig = sig->next) |
3045f050 | 762 | { /* Finish hashes */ |
2592e6c0 JH |
763 | blob bh; |
764 | ||
765 | exim_sha_finish(&sig->body_hash, &bh); | |
3045f050 | 766 | |
0d04a285 | 767 | DEBUG(D_acl) |
3045f050 | 768 | { |
0d04a285 JH |
769 | debug_printf("PDKIM [%s] Body bytes hashed: %lu\n" |
770 | "PDKIM [%s] bh computed: ", | |
771 | sig->domain, sig->signed_body_bytes, sig->domain); | |
b78006ac | 772 | pdkim_hexprint(CUS bh.data, bh.len); |
80a47a2c | 773 | } |
3045f050 JH |
774 | |
775 | /* SIGNING -------------------------------------------------------------- */ | |
776 | if (ctx->mode == PDKIM_MODE_SIGN) | |
777 | { | |
2592e6c0 | 778 | sig->bodyhash = bh; |
3045f050 JH |
779 | |
780 | /* If bodylength limit is set, and we have received less bytes | |
781 | than the requested amount, effectively remove the limit tag. */ | |
782 | if (sig->signed_body_bytes < sig->bodylength) | |
783 | sig->bodylength = -1; | |
80a47a2c | 784 | } |
3045f050 JH |
785 | |
786 | /* VERIFICATION --------------------------------------------------------- */ | |
787 | else | |
788 | { | |
789 | /* Compare bodyhash */ | |
2592e6c0 | 790 | if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) |
3045f050 | 791 | { |
0d04a285 | 792 | DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain); |
80a47a2c | 793 | } |
3045f050 JH |
794 | else |
795 | { | |
0d04a285 | 796 | DEBUG(D_acl) |
3045f050 | 797 | { |
0d04a285 | 798 | debug_printf("PDKIM [%s] bh signature: ", sig->domain); |
2592e6c0 JH |
799 | pdkim_hexprint(sig->bodyhash.data, |
800 | exim_sha_hashlen(&sig->body_hash)); | |
0d04a285 | 801 | debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain); |
3045f050 | 802 | } |
3045f050 JH |
803 | sig->verify_status = PDKIM_VERIFY_FAIL; |
804 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; | |
80a47a2c TK |
805 | } |
806 | } | |
80a47a2c | 807 | } |
6ab02e3f | 808 | } |
80a47a2c TK |
809 | |
810 | ||
811 | ||
812 | /* -------------------------------------------------------------------------- */ | |
813 | /* Callback from pdkim_feed below for processing complete body lines */ | |
3045f050 | 814 | |
0d04a285 | 815 | static int |
3045f050 JH |
816 | pdkim_bodyline_complete(pdkim_ctx *ctx) |
817 | { | |
818 | char *p = ctx->linebuf; | |
819 | int n = ctx->linebuf_offset; | |
c14470c3 | 820 | pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */ |
3045f050 JH |
821 | |
822 | /* Ignore extra data if we've seen the end-of-data marker */ | |
823 | if (ctx->seen_eod) goto BAIL; | |
824 | ||
825 | /* We've always got one extra byte to stuff a zero ... */ | |
0d04a285 | 826 | ctx->linebuf[ctx->linebuf_offset] = '\0'; |
3045f050 | 827 | |
0d04a285 JH |
828 | /* Terminate on EOD marker */ |
829 | if (memcmp(p, ".\r\n", 3) == 0) | |
3045f050 | 830 | { |
0d04a285 JH |
831 | /* In simple body mode, if any empty lines were buffered, |
832 | replace with one. rfc 4871 3.4.3 */ | |
833 | /*XXX checking the signed-body-bytes is a gross hack; I think | |
834 | it indicates that all linebreaks should be buffered, including | |
835 | the one terminating a text line */ | |
836 | if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE | |
837 | && sig->signed_body_bytes == 0 | |
838 | && ctx->num_buffered_crlf > 0 | |
839 | ) | |
840 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
841 | ||
842 | ctx->seen_eod = TRUE; | |
843 | goto BAIL; | |
844 | } | |
845 | /* Unstuff dots */ | |
846 | if (memcmp(p, "..", 2) == 0) | |
847 | { | |
848 | p++; | |
849 | n--; | |
80a47a2c TK |
850 | } |
851 | ||
3045f050 JH |
852 | /* Empty lines need to be buffered until we find a non-empty line */ |
853 | if (memcmp(p, "\r\n", 2) == 0) | |
854 | { | |
855 | ctx->num_buffered_crlf++; | |
856 | goto BAIL; | |
80a47a2c TK |
857 | } |
858 | ||
c14470c3 | 859 | if (sig && sig->canon_body == PDKIM_CANON_RELAXED) |
3045f050 JH |
860 | { |
861 | /* Lines with just spaces need to be buffered too */ | |
862 | char *check = p; | |
863 | while (memcmp(check, "\r\n", 2) != 0) | |
864 | { | |
865 | char c = *check; | |
6a11a9e6 | 866 | |
3045f050 JH |
867 | if (c != '\t' && c != ' ') |
868 | goto PROCESS; | |
869 | check++; | |
6a11a9e6 JH |
870 | } |
871 | ||
3045f050 JH |
872 | ctx->num_buffered_crlf++; |
873 | goto BAIL; | |
874 | } | |
6a11a9e6 | 875 | |
3045f050 JH |
876 | PROCESS: |
877 | /* At this point, we have a non-empty line, so release the buffered ones. */ | |
878 | while (ctx->num_buffered_crlf) | |
879 | { | |
880 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
881 | ctx->num_buffered_crlf--; | |
80a47a2c TK |
882 | } |
883 | ||
3045f050 | 884 | pdkim_update_bodyhash(ctx, p, n); |
80a47a2c | 885 | |
3045f050 JH |
886 | BAIL: |
887 | ctx->linebuf_offset = 0; | |
888 | return PDKIM_OK; | |
80a47a2c TK |
889 | } |
890 | ||
891 | ||
892 | /* -------------------------------------------------------------------------- */ | |
893 | /* Callback from pdkim_feed below for processing complete headers */ | |
894 | #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" | |
3045f050 | 895 | |
f444c2c7 | 896 | static int |
3045f050 JH |
897 | pdkim_header_complete(pdkim_ctx *ctx) |
898 | { | |
3045f050 | 899 | /* Special case: The last header can have an extra \r appended */ |
ca9cb170 JH |
900 | if ( (ctx->cur_header_len > 1) && |
901 | (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') ) | |
902 | --ctx->cur_header_len; | |
903 | ctx->cur_header[ctx->cur_header_len] = '\0'; | |
80a47a2c | 904 | |
3045f050 JH |
905 | ctx->num_headers++; |
906 | if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; | |
80a47a2c | 907 | |
3045f050 JH |
908 | /* SIGNING -------------------------------------------------------------- */ |
909 | if (ctx->mode == PDKIM_MODE_SIGN) | |
0d04a285 JH |
910 | { |
911 | pdkim_signature *sig; | |
912 | ||
913 | for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */ | |
80a47a2c | 914 | |
ab9152ff | 915 | /* Add header to the signed headers list (in reverse order) */ |
ca9cb170 JH |
916 | sig->headers = pdkim_prepend_stringlist(sig->headers, |
917 | ctx->cur_header); | |
0d04a285 | 918 | } |
94431adb | 919 | |
0d04a285 | 920 | /* VERIFICATION ----------------------------------------------------------- */ |
3045f050 JH |
921 | /* DKIM-Signature: headers are added to the verification list */ |
922 | if (ctx->mode == PDKIM_MODE_VERIFY) | |
923 | { | |
e2e3255a | 924 | if (strncasecmp(CCS ctx->cur_header, |
3045f050 | 925 | DKIM_SIGNATURE_HEADERNAME, |
e2e3255a | 926 | Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0) |
3045f050 JH |
927 | { |
928 | pdkim_signature *new_sig; | |
80a47a2c | 929 | |
3045f050 | 930 | /* Create and chain new signature block */ |
0d04a285 | 931 | DEBUG(D_acl) debug_printf( |
3045f050 | 932 | "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 | 933 | |
ca9cb170 | 934 | if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header))) |
3045f050 JH |
935 | { |
936 | pdkim_signature *last_sig = ctx->sig; | |
937 | if (!last_sig) | |
938 | ctx->sig = new_sig; | |
939 | else | |
940 | { | |
941 | while (last_sig->next) last_sig = last_sig->next; | |
942 | last_sig->next = new_sig; | |
943 | } | |
80a47a2c | 944 | } |
abe1010c | 945 | else |
0d04a285 JH |
946 | DEBUG(D_acl) debug_printf( |
947 | "Error while parsing signature header\n" | |
3045f050 | 948 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 949 | } |
37f8b554 | 950 | |
3045f050 JH |
951 | /* every other header is stored for signature verification */ |
952 | else | |
ca9cb170 | 953 | ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); |
80a47a2c TK |
954 | } |
955 | ||
3045f050 | 956 | BAIL: |
ca9cb170 JH |
957 | *ctx->cur_header = '\0'; |
958 | ctx->cur_header_len = 0; /* leave buffer for reuse */ | |
3045f050 | 959 | return PDKIM_OK; |
6ab02e3f | 960 | } |
80a47a2c TK |
961 | |
962 | ||
963 | ||
964 | /* -------------------------------------------------------------------------- */ | |
965 | #define HEADER_BUFFER_FRAG_SIZE 256 | |
3045f050 JH |
966 | |
967 | DLLEXPORT int | |
ca9cb170 | 968 | pdkim_feed(pdkim_ctx *ctx, char *data, int len) |
3045f050 JH |
969 | { |
970 | int p; | |
971 | ||
972 | for (p = 0; p<len; p++) | |
973 | { | |
ca9cb170 | 974 | uschar c = data[p]; |
3045f050 JH |
975 | |
976 | if (ctx->past_headers) | |
977 | { | |
978 | /* Processing body byte */ | |
0d04a285 | 979 | ctx->linebuf[ctx->linebuf_offset++] = c; |
3045f050 JH |
980 | if (c == '\n') |
981 | { | |
982 | int rc = pdkim_bodyline_complete(ctx); /* End of line */ | |
983 | if (rc != PDKIM_OK) return rc; | |
80a47a2c | 984 | } |
3045f050 JH |
985 | if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1)) |
986 | return PDKIM_ERR_LONG_LINE; | |
80a47a2c | 987 | } |
3045f050 JH |
988 | else |
989 | { | |
990 | /* Processing header byte */ | |
991 | if (c != '\r') | |
992 | { | |
993 | if (c == '\n') | |
994 | { | |
995 | if (ctx->seen_lf) | |
996 | { | |
997 | int rc = pdkim_header_complete(ctx); /* Seen last header line */ | |
998 | if (rc != PDKIM_OK) return rc; | |
999 | ||
0d04a285 | 1000 | ctx->past_headers = TRUE; |
3045f050 | 1001 | ctx->seen_lf = 0; |
0d04a285 | 1002 | DEBUG(D_acl) debug_printf( |
8ef02a06 | 1003 | "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 JH |
1004 | continue; |
1005 | } | |
1006 | else | |
0d04a285 | 1007 | ctx->seen_lf = TRUE; |
3045f050 JH |
1008 | } |
1009 | else if (ctx->seen_lf) | |
1010 | { | |
1011 | if (!(c == '\t' || c == ' ')) | |
1012 | { | |
1013 | int rc = pdkim_header_complete(ctx); /* End of header */ | |
1014 | if (rc != PDKIM_OK) return rc; | |
1015 | } | |
0d04a285 | 1016 | ctx->seen_lf = FALSE; |
3045f050 | 1017 | } |
80a47a2c | 1018 | } |
3045f050 | 1019 | |
ca9cb170 | 1020 | if (ctx->cur_header_len < PDKIM_MAX_HEADER_LEN) |
c2f669a4 | 1021 | ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, |
e2e3255a | 1022 | &ctx->cur_header_len, CUS &data[p], 1); |
80a47a2c TK |
1023 | } |
1024 | } | |
3045f050 | 1025 | return PDKIM_OK; |
6ab02e3f | 1026 | } |
80a47a2c | 1027 | |
ca9cb170 JH |
1028 | |
1029 | ||
1030 | /* Extend a grwong header with a continuation-linebreak */ | |
1031 | static uschar * | |
1032 | pdkim_hdr_cont(uschar * str, int * size, int * ptr, int * col) | |
1033 | { | |
1034 | *col = 1; | |
c2f669a4 | 1035 | return string_catn(str, size, ptr, US"\r\n\t", 3); |
ca9cb170 JH |
1036 | } |
1037 | ||
1038 | ||
1039 | ||
05b7d6de JB |
1040 | /* |
1041 | * RFC 5322 specifies that header line length SHOULD be no more than 78 | |
1042 | * lets make it so! | |
1043 | * pdkim_headcat | |
ca9cb170 JH |
1044 | * |
1045 | * returns uschar * (not nul-terminated) | |
05b7d6de JB |
1046 | * |
1047 | * col: this int holds and receives column number (octets since last '\n') | |
1048 | * str: partial string to append to | |
ca9cb170 JH |
1049 | * size: current buffer size for str |
1050 | * ptr: current tail-pointer for str | |
94431adb | 1051 | * pad: padding, split line or space after before or after eg: ";" |
05b7d6de JB |
1052 | * intro: - must join to payload eg "h=", usually the tag name |
1053 | * payload: eg base64 data - long data can be split arbitrarily. | |
1054 | * | |
1055 | * this code doesn't fold the header in some of the places that RFC4871 | |
1056 | * allows: As per RFC5322(2.2.3) it only folds before or after tag-value | |
1057 | * pairs and inside long values. it also always spaces or breaks after the | |
94431adb | 1058 | * "pad" |
05b7d6de JB |
1059 | * |
1060 | * no guarantees are made for output given out-of range input. like tag | |
f444c2c7 | 1061 | * names longer than 78, or bogus col. Input is assumed to be free of line breaks. |
05b7d6de JB |
1062 | */ |
1063 | ||
ca9cb170 JH |
1064 | static uschar * |
1065 | pdkim_headcat(int * col, uschar * str, int * size, int * ptr, | |
1066 | const uschar * pad, const uschar * intro, const uschar * payload) | |
3045f050 JH |
1067 | { |
1068 | size_t l; | |
1069 | ||
1070 | if (pad) | |
05b7d6de | 1071 | { |
ca9cb170 | 1072 | l = Ustrlen(pad); |
3045f050 | 1073 | if (*col + l > 78) |
ca9cb170 | 1074 | str = pdkim_hdr_cont(str, size, ptr, col); |
c2f669a4 | 1075 | str = string_catn(str, size, ptr, pad, l); |
3045f050 | 1076 | *col += l; |
05b7d6de JB |
1077 | } |
1078 | ||
ca9cb170 | 1079 | l = (pad?1:0) + (intro?Ustrlen(intro):0); |
05b7d6de | 1080 | |
3045f050 | 1081 | if (*col + l > 78) |
05b7d6de | 1082 | { /*can't fit intro - start a new line to make room.*/ |
ca9cb170 JH |
1083 | str = pdkim_hdr_cont(str, size, ptr, col); |
1084 | l = intro?Ustrlen(intro):0; | |
05b7d6de JB |
1085 | } |
1086 | ||
ca9cb170 | 1087 | l += payload ? Ustrlen(payload):0 ; |
05b7d6de | 1088 | |
3045f050 | 1089 | while (l>77) |
05b7d6de | 1090 | { /* this fragment will not fit on a single line */ |
3045f050 | 1091 | if (pad) |
05b7d6de | 1092 | { |
c2f669a4 | 1093 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1094 | *col += 1; |
1095 | pad = NULL; /* only want this once */ | |
1096 | l--; | |
05b7d6de | 1097 | } |
3045f050 JH |
1098 | |
1099 | if (intro) | |
05b7d6de | 1100 | { |
ca9cb170 | 1101 | size_t sl = Ustrlen(intro); |
3045f050 | 1102 | |
c2f669a4 | 1103 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1104 | *col += sl; |
1105 | l -= sl; | |
1106 | intro = NULL; /* only want this once */ | |
05b7d6de | 1107 | } |
3045f050 JH |
1108 | |
1109 | if (payload) | |
05b7d6de | 1110 | { |
ca9cb170 | 1111 | size_t sl = Ustrlen(payload); |
3045f050 JH |
1112 | size_t chomp = *col+sl < 77 ? sl : 78-*col; |
1113 | ||
c2f669a4 | 1114 | str = string_catn(str, size, ptr, payload, chomp); |
3045f050 JH |
1115 | *col += chomp; |
1116 | payload += chomp; | |
1117 | l -= chomp-1; | |
05b7d6de | 1118 | } |
3045f050 JH |
1119 | |
1120 | /* the while precondition tells us it didn't fit. */ | |
ca9cb170 | 1121 | str = pdkim_hdr_cont(str, size, ptr, col); |
05b7d6de | 1122 | } |
3045f050 JH |
1123 | |
1124 | if (*col + l > 78) | |
05b7d6de | 1125 | { |
ca9cb170 | 1126 | str = pdkim_hdr_cont(str, size, ptr, col); |
3045f050 | 1127 | pad = NULL; |
05b7d6de JB |
1128 | } |
1129 | ||
3045f050 | 1130 | if (pad) |
05b7d6de | 1131 | { |
c2f669a4 | 1132 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1133 | *col += 1; |
1134 | pad = NULL; | |
05b7d6de JB |
1135 | } |
1136 | ||
3045f050 | 1137 | if (intro) |
05b7d6de | 1138 | { |
ca9cb170 | 1139 | size_t sl = Ustrlen(intro); |
3045f050 | 1140 | |
c2f669a4 | 1141 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1142 | *col += sl; |
1143 | l -= sl; | |
1144 | intro = NULL; | |
05b7d6de | 1145 | } |
3045f050 JH |
1146 | |
1147 | if (payload) | |
05b7d6de | 1148 | { |
ca9cb170 | 1149 | size_t sl = Ustrlen(payload); |
3045f050 | 1150 | |
c2f669a4 | 1151 | str = string_catn(str, size, ptr, payload, sl); |
3045f050 | 1152 | *col += sl; |
05b7d6de JB |
1153 | } |
1154 | ||
ca9cb170 | 1155 | return str; |
05b7d6de | 1156 | } |
80a47a2c | 1157 | |
3045f050 | 1158 | |
80a47a2c | 1159 | /* -------------------------------------------------------------------------- */ |
3045f050 | 1160 | |
ca9cb170 | 1161 | static uschar * |
2592e6c0 | 1162 | pdkim_create_header(pdkim_signature *sig, BOOL final) |
3045f050 | 1163 | { |
ca9cb170 JH |
1164 | uschar * base64_bh; |
1165 | uschar * base64_b; | |
3045f050 | 1166 | int col = 0; |
ca9cb170 JH |
1167 | uschar * hdr; int hdr_size = 0, hdr_len = 0; |
1168 | uschar * canon_all; int can_size = 0, can_len = 0; | |
3045f050 | 1169 | |
c2f669a4 JH |
1170 | canon_all = string_cat (NULL, &can_size, &can_len, |
1171 | pdkim_canons[sig->canon_headers]); | |
1172 | canon_all = string_catn(canon_all, &can_size, &can_len, US"/", 1); | |
1173 | canon_all = string_cat (canon_all, &can_size, &can_len, | |
1174 | pdkim_canons[sig->canon_body]); | |
ca9cb170 | 1175 | canon_all[can_len] = '\0'; |
3045f050 | 1176 | |
ca9cb170 | 1177 | hdr = string_cat(NULL, &hdr_size, &hdr_len, |
e2e3255a | 1178 | US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION); |
ca9cb170 | 1179 | col = hdr_len; |
3045f050 JH |
1180 | |
1181 | /* Required and static bits */ | |
ca9cb170 JH |
1182 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"a=", |
1183 | pdkim_algos[sig->algo]); | |
1184 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"q=", | |
1185 | pdkim_querymethods[sig->querymethod]); | |
1186 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"c=", | |
1187 | canon_all); | |
1188 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"d=", | |
1189 | sig->domain); | |
1190 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"s=", | |
1191 | sig->selector); | |
1192 | ||
1193 | /* list of header names can be split between items. */ | |
3045f050 | 1194 | { |
e2e3255a | 1195 | uschar * n = string_copy(sig->headernames); |
ca9cb170 JH |
1196 | uschar * i = US"h="; |
1197 | uschar * s = US";"; | |
1198 | ||
1199 | while (*n) | |
05b7d6de | 1200 | { |
ca9cb170 | 1201 | uschar * c = Ustrchr(n, ':'); |
3045f050 | 1202 | |
ca9cb170 | 1203 | if (c) *c ='\0'; |
05b7d6de | 1204 | |
ca9cb170 JH |
1205 | if (!i) |
1206 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, NULL, US":"); | |
05b7d6de | 1207 | |
ca9cb170 | 1208 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, s, i, n); |
3045f050 | 1209 | |
ca9cb170 JH |
1210 | if (!c) |
1211 | break; | |
3045f050 | 1212 | |
ca9cb170 JH |
1213 | n = c+1; |
1214 | s = NULL; | |
1215 | i = NULL; | |
80a47a2c | 1216 | } |
ca9cb170 | 1217 | } |
05b7d6de | 1218 | |
ca9cb170 JH |
1219 | base64_bh = pdkim_encode_base64(&sig->bodyhash); |
1220 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"bh=", base64_bh); | |
3045f050 | 1221 | |
ca9cb170 JH |
1222 | /* Optional bits */ |
1223 | if (sig->identity) | |
1224 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"i=", sig->identity); | |
3045f050 | 1225 | |
ca9cb170 JH |
1226 | if (sig->created > 0) |
1227 | { | |
e2e3255a | 1228 | uschar minibuf[20]; |
3045f050 | 1229 | |
e2e3255a | 1230 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created); |
ca9cb170 JH |
1231 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"t=", minibuf); |
1232 | } | |
3045f050 | 1233 | |
ca9cb170 JH |
1234 | if (sig->expires > 0) |
1235 | { | |
e2e3255a | 1236 | uschar minibuf[20]; |
3045f050 | 1237 | |
e2e3255a | 1238 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires); |
ca9cb170 JH |
1239 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"x=", minibuf); |
1240 | } | |
3045f050 | 1241 | |
ca9cb170 JH |
1242 | if (sig->bodylength >= 0) |
1243 | { | |
e2e3255a | 1244 | uschar minibuf[20]; |
80a47a2c | 1245 | |
e2e3255a | 1246 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength); |
ca9cb170 | 1247 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"l=", minibuf); |
3045f050 | 1248 | } |
05b7d6de | 1249 | |
ca9cb170 JH |
1250 | /* Preliminary or final version? */ |
1251 | base64_b = final ? pdkim_encode_base64(&sig->sigdata) : US""; | |
1252 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b); | |
80a47a2c | 1253 | |
ca9cb170 JH |
1254 | /* add trailing semicolon: I'm not sure if this is actually needed */ |
1255 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, US";", US""); | |
80a47a2c | 1256 | |
ca9cb170 JH |
1257 | hdr[hdr_len] = '\0'; |
1258 | return hdr; | |
80a47a2c TK |
1259 | } |
1260 | ||
1261 | ||
1262 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1263 | |
1264 | DLLEXPORT int | |
1265 | pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) | |
1266 | { | |
1267 | pdkim_signature *sig = ctx->sig; | |
ca9cb170 JH |
1268 | uschar * headernames = NULL; /* Collected signed header names */ |
1269 | int hs = 0, hl = 0; | |
3045f050 JH |
1270 | |
1271 | /* Check if we must still flush a (partial) header. If that is the | |
1272 | case, the message has no body, and we must compute a body hash | |
1273 | out of '<CR><LF>' */ | |
ca9cb170 | 1274 | if (ctx->cur_header && ctx->cur_header_len) |
3045f050 JH |
1275 | { |
1276 | int rc = pdkim_header_complete(ctx); | |
1277 | if (rc != PDKIM_OK) return rc; | |
1278 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
80a47a2c | 1279 | } |
3045f050 | 1280 | else |
0d04a285 | 1281 | DEBUG(D_acl) debug_printf( |
3045f050 | 1282 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1283 | |
3045f050 | 1284 | /* Build (and/or evaluate) body hash */ |
ca9cb170 | 1285 | pdkim_finish_bodyhash(ctx); |
80a47a2c | 1286 | |
3045f050 JH |
1287 | while (sig) |
1288 | { | |
2592e6c0 JH |
1289 | BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1; |
1290 | hctx hhash_ctx; | |
ca9cb170 | 1291 | uschar * sig_hdr; |
2592e6c0 JH |
1292 | blob hhash; |
1293 | blob hdata; | |
cb224393 | 1294 | int hdata_alloc = 0; |
cb224393 | 1295 | |
2592e6c0 JH |
1296 | hdata.data = NULL; |
1297 | hdata.len = 0; | |
1298 | ||
1ed59855 | 1299 | exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256); |
80a47a2c | 1300 | |
0d04a285 JH |
1301 | DEBUG(D_acl) debug_printf( |
1302 | "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n"); | |
3045f050 JH |
1303 | |
1304 | /* SIGNING ---------------------------------------------------------------- */ | |
1305 | /* When signing, walk through our header list and add them to the hash. As we | |
8ef02a06 JH |
1306 | go, construct a list of the header's names to use for the h= parameter. |
1307 | Then append to that list any remaining header names for which there was no | |
1308 | header to sign. */ | |
3045f050 JH |
1309 | |
1310 | if (ctx->mode == PDKIM_MODE_SIGN) | |
1311 | { | |
1312 | pdkim_stringlist *p; | |
8ef02a06 JH |
1313 | const uschar * l; |
1314 | uschar * s; | |
1315 | int sep = 0; | |
3045f050 JH |
1316 | |
1317 | for (p = sig->headers; p; p = p->next) | |
ab9152ff JH |
1318 | if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK) |
1319 | { | |
1320 | uschar * rh; | |
1321 | /* Collect header names (Note: colon presence is guaranteed here) */ | |
1322 | uschar * q = Ustrchr(p->value, ':'); | |
3045f050 | 1323 | |
c2f669a4 | 1324 | headernames = string_catn(headernames, &hs, &hl, |
ca9cb170 | 1325 | p->value, (q - US p->value) + (p->next ? 1 : 0)); |
3045f050 | 1326 | |
ab9152ff | 1327 | rh = sig->canon_headers == PDKIM_CANON_RELAXED |
ca9cb170 JH |
1328 | ? pdkim_relax_header(p->value, 1) /* cook header for relaxed canon */ |
1329 | : string_copy(CUS p->value); /* just copy it for simple canon */ | |
3045f050 | 1330 | |
ab9152ff | 1331 | /* Feed header to the hash algorithm */ |
e2e3255a | 1332 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); |
f444c2c7 | 1333 | |
ab9152ff JH |
1334 | /* Remember headers block for signing (when the library cannot do incremental) */ |
1335 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, rh); | |
3045f050 | 1336 | |
ab9152ff JH |
1337 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); |
1338 | } | |
8ef02a06 | 1339 | |
ca9cb170 | 1340 | l = sig->sign_headers; |
8ef02a06 JH |
1341 | while((s = string_nextinlist(&l, &sep, NULL, 0))) |
1342 | if (*s != '_') | |
ab9152ff | 1343 | { /*SSS string_append_listele() */ |
ca9cb170 | 1344 | if (hl > 0 && headernames[hl-1] != ':') |
c2f669a4 | 1345 | headernames = string_catn(headernames, &hs, &hl, US":", 1); |
ca9cb170 | 1346 | |
c2f669a4 | 1347 | headernames = string_cat(headernames, &hs, &hl, s); |
8ef02a06 | 1348 | } |
ca9cb170 JH |
1349 | headernames[hl] = '\0'; |
1350 | ||
1351 | /* Copy headernames to signature struct */ | |
1352 | sig->headernames = headernames; | |
1353 | headernames = NULL, hs = hl = 0; | |
1354 | ||
1355 | /* Create signature header with b= omitted */ | |
1356 | sig_hdr = pdkim_create_header(sig, FALSE); | |
80a47a2c | 1357 | } |
37f8b554 | 1358 | |
3045f050 JH |
1359 | /* VERIFICATION ----------------------------------------------------------- */ |
1360 | /* When verifying, walk through the header name list in the h= parameter and | |
1361 | add the headers to the hash in that order. */ | |
1362 | else | |
1363 | { | |
2592e6c0 JH |
1364 | uschar * b = string_copy(sig->headernames); |
1365 | uschar * p = b; | |
1366 | uschar * q; | |
1367 | pdkim_stringlist * hdrs; | |
3045f050 | 1368 | |
3045f050 JH |
1369 | /* clear tags */ |
1370 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) | |
1371 | hdrs->tag = 0; | |
1372 | ||
1373 | while(1) | |
1374 | { | |
2592e6c0 | 1375 | if ((q = Ustrchr(p, ':'))) |
3045f050 JH |
1376 | *q = '\0'; |
1377 | ||
ab9152ff | 1378 | /*XXX walk the list of headers in same order as received. */ |
3045f050 JH |
1379 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) |
1380 | if ( hdrs->tag == 0 | |
2592e6c0 JH |
1381 | && strncasecmp(hdrs->value, CS p, Ustrlen(p)) == 0 |
1382 | && (hdrs->value)[Ustrlen(p)] == ':' | |
3045f050 JH |
1383 | ) |
1384 | { | |
2592e6c0 | 1385 | uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED |
ca9cb170 JH |
1386 | ? pdkim_relax_header(hdrs->value, 1) /* cook header for relaxed canon */ |
1387 | : string_copy(CUS hdrs->value); /* just copy it for simple canon */ | |
3045f050 JH |
1388 | |
1389 | /* Feed header to the hash algorithm */ | |
e2e3255a | 1390 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); |
3045f050 | 1391 | |
2592e6c0 | 1392 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); |
3045f050 JH |
1393 | hdrs->tag = 1; |
1394 | break; | |
1395 | } | |
1396 | ||
1397 | if (!q) break; | |
1398 | p = q+1; | |
80a47a2c | 1399 | } |
ca9cb170 JH |
1400 | |
1401 | sig_hdr = string_copy(sig->rawsig_no_b_val); | |
80a47a2c TK |
1402 | } |
1403 | ||
0d04a285 | 1404 | DEBUG(D_acl) debug_printf( |
3045f050 | 1405 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1406 | |
3045f050 JH |
1407 | /* Relax header if necessary */ |
1408 | if (sig->canon_headers == PDKIM_CANON_RELAXED) | |
ca9cb170 | 1409 | sig_hdr = pdkim_relax_header(sig_hdr, 0); |
80a47a2c | 1410 | |
0d04a285 | 1411 | DEBUG(D_acl) |
3045f050 | 1412 | { |
0d04a285 | 1413 | debug_printf( |
3045f050 | 1414 | "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 1415 | pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr)); |
0d04a285 | 1416 | debug_printf( |
3045f050 | 1417 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1418 | } |
3045f050 JH |
1419 | |
1420 | /* Finalize header hash */ | |
e2e3255a | 1421 | exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr)); |
2592e6c0 | 1422 | exim_sha_finish(&hhash_ctx, &hhash); |
3045f050 | 1423 | |
f444c2c7 JH |
1424 | DEBUG(D_acl) |
1425 | { | |
1426 | debug_printf("PDKIM [%s] hh computed: ", sig->domain); | |
2592e6c0 | 1427 | pdkim_hexprint(hhash.data, hhash.len); |
80a47a2c TK |
1428 | } |
1429 | ||
2592e6c0 | 1430 | /* Remember headers block for signing (when the library cannot do incremental) */ |
f444c2c7 | 1431 | if (ctx->mode == PDKIM_MODE_SIGN) |
b78006ac | 1432 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, US sig_hdr); |
f444c2c7 | 1433 | |
3045f050 JH |
1434 | /* SIGNING ---------------------------------------------------------------- */ |
1435 | if (ctx->mode == PDKIM_MODE_SIGN) | |
1436 | { | |
2592e6c0 JH |
1437 | es_ctx sctx; |
1438 | const uschar * errstr; | |
f444c2c7 JH |
1439 | |
1440 | /* Import private key */ | |
b78006ac | 1441 | if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &sctx))) |
f444c2c7 | 1442 | { |
2592e6c0 | 1443 | DEBUG(D_acl) debug_printf("signing_init: %s\n", errstr); |
f444c2c7 JH |
1444 | return PDKIM_ERR_RSA_PRIVKEY; |
1445 | } | |
80a47a2c | 1446 | |
2592e6c0 JH |
1447 | /* Do signing. With OpenSSL we are signing the hash of headers just |
1448 | calculated, with GnuTLS we have to sign an entire block of headers | |
1449 | (due to available interfaces) and it recalculates the hash internally. */ | |
f444c2c7 | 1450 | |
2592e6c0 JH |
1451 | #if defined(RSA_OPENSSL) || defined(RSA_GCRYPT) |
1452 | hdata = hhash; | |
f444c2c7 JH |
1453 | #endif |
1454 | ||
2592e6c0 | 1455 | if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata))) |
f444c2c7 | 1456 | { |
2592e6c0 | 1457 | DEBUG(D_acl) debug_printf("signing: %s\n", errstr); |
f444c2c7 JH |
1458 | return PDKIM_ERR_RSA_SIGNING; |
1459 | } | |
80a47a2c | 1460 | |
0d04a285 | 1461 | DEBUG(D_acl) |
3045f050 | 1462 | { |
0d04a285 | 1463 | debug_printf( "PDKIM [%s] b computed: ", sig->domain); |
2592e6c0 | 1464 | pdkim_hexprint(sig->sigdata.data, sig->sigdata.len); |
80a47a2c | 1465 | } |
80a47a2c | 1466 | |
ca9cb170 | 1467 | sig->signature_header = pdkim_create_header(sig, TRUE); |
80a47a2c | 1468 | } |
80a47a2c | 1469 | |
3045f050 JH |
1470 | /* VERIFICATION ----------------------------------------------------------- */ |
1471 | else | |
1472 | { | |
2592e6c0 JH |
1473 | ev_ctx vctx; |
1474 | const uschar * errstr; | |
3045f050 | 1475 | |
ca9cb170 | 1476 | uschar *dns_txt_name, *dns_txt_reply; |
f444c2c7 JH |
1477 | |
1478 | /* Fetch public key for signing domain, from DNS */ | |
3045f050 | 1479 | |
ca9cb170 JH |
1480 | dns_txt_name = string_sprintf("%s._domainkey.%s.", |
1481 | sig->selector, sig->domain); | |
80a47a2c | 1482 | |
ca9cb170 | 1483 | dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1484 | memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1485 | |
ca9cb170 | 1486 | if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK |
3045f050 JH |
1487 | || dns_txt_reply[0] == '\0') |
1488 | { | |
1489 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1490 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE; | |
1491 | goto NEXT_VERIFY; | |
80a47a2c TK |
1492 | } |
1493 | ||
0d04a285 | 1494 | DEBUG(D_acl) |
3045f050 | 1495 | { |
0d04a285 | 1496 | debug_printf( |
2592e6c0 JH |
1497 | "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" |
1498 | " Raw record: "); | |
ca9cb170 | 1499 | pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply)); |
80a47a2c | 1500 | } |
3045f050 | 1501 | |
e2e3255a | 1502 | if (!(sig->pubkey = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply))) |
3045f050 JH |
1503 | { |
1504 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
df3def24 | 1505 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD; |
3045f050 | 1506 | |
0d04a285 JH |
1507 | DEBUG(D_acl) debug_printf( |
1508 | " Error while parsing public key record\n" | |
3045f050 | 1509 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
3045f050 | 1510 | goto NEXT_VERIFY; |
80a47a2c TK |
1511 | } |
1512 | ||
0d04a285 | 1513 | DEBUG(D_acl) debug_printf( |
2592e6c0 | 1514 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
3045f050 | 1515 | |
f444c2c7 | 1516 | /* Import public key */ |
2592e6c0 | 1517 | if ((errstr = exim_rsa_verify_init(&sig->pubkey->key, &vctx))) |
3045f050 | 1518 | { |
2592e6c0 | 1519 | DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr); |
3045f050 | 1520 | sig->verify_status = PDKIM_VERIFY_INVALID; |
df3def24 | 1521 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; |
3045f050 | 1522 | goto NEXT_VERIFY; |
80a47a2c TK |
1523 | } |
1524 | ||
3045f050 | 1525 | /* Check the signature */ |
2592e6c0 | 1526 | if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata))) |
3045f050 | 1527 | { |
2592e6c0 | 1528 | DEBUG(D_acl) debug_printf("headers verify: %s\n", errstr); |
3045f050 JH |
1529 | sig->verify_status = PDKIM_VERIFY_FAIL; |
1530 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; | |
1531 | goto NEXT_VERIFY; | |
ff7ddfd7 TK |
1532 | } |
1533 | ||
2592e6c0 | 1534 | |
3045f050 JH |
1535 | /* We have a winner! (if bodydhash was correct earlier) */ |
1536 | if (sig->verify_status == PDKIM_VERIFY_NONE) | |
1537 | sig->verify_status = PDKIM_VERIFY_PASS; | |
1538 | ||
1539 | NEXT_VERIFY: | |
1540 | ||
0d04a285 | 1541 | DEBUG(D_acl) |
3045f050 | 1542 | { |
0d04a285 | 1543 | debug_printf("PDKIM [%s] signature status: %s", |
3045f050 JH |
1544 | sig->domain, pdkim_verify_status_str(sig->verify_status)); |
1545 | if (sig->verify_ext_status > 0) | |
0d04a285 | 1546 | debug_printf(" (%s)\n", |
3045f050 JH |
1547 | pdkim_verify_ext_status_str(sig->verify_ext_status)); |
1548 | else | |
0d04a285 | 1549 | debug_printf("\n"); |
80a47a2c | 1550 | } |
80a47a2c TK |
1551 | } |
1552 | ||
3045f050 | 1553 | sig = sig->next; |
80a47a2c TK |
1554 | } |
1555 | ||
3045f050 JH |
1556 | /* If requested, set return pointer to signature(s) */ |
1557 | if (return_signatures) | |
1558 | *return_signatures = ctx->sig; | |
80a47a2c | 1559 | |
3045f050 | 1560 | return PDKIM_OK; |
80a47a2c TK |
1561 | } |
1562 | ||
1563 | ||
1564 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1565 | |
1566 | DLLEXPORT pdkim_ctx * | |
0d04a285 | 1567 | pdkim_init_verify(int(*dns_txt_callback)(char *, char *)) |
3045f050 | 1568 | { |
ca9cb170 | 1569 | pdkim_ctx * ctx; |
3045f050 | 1570 | |
ca9cb170 | 1571 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1572 | memset(ctx, 0, sizeof(pdkim_ctx)); |
3045f050 | 1573 | |
ca9cb170 | 1574 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
3045f050 | 1575 | ctx->mode = PDKIM_MODE_VERIFY; |
3045f050 | 1576 | ctx->dns_txt_callback = dns_txt_callback; |
80a47a2c | 1577 | |
3045f050 | 1578 | return ctx; |
80a47a2c TK |
1579 | } |
1580 | ||
1581 | ||
1582 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 1583 | |
3045f050 | 1584 | DLLEXPORT pdkim_ctx * |
f444c2c7 | 1585 | pdkim_init_sign(char *domain, char *selector, char *rsa_privkey, int algo) |
3045f050 JH |
1586 | { |
1587 | pdkim_ctx *ctx; | |
1588 | pdkim_signature *sig; | |
80a47a2c | 1589 | |
3045f050 JH |
1590 | if (!domain || !selector || !rsa_privkey) |
1591 | return NULL; | |
80a47a2c | 1592 | |
ca9cb170 | 1593 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1594 | memset(ctx, 0, sizeof(pdkim_ctx)); |
80a47a2c | 1595 | |
ca9cb170 | 1596 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
80a47a2c | 1597 | |
ca9cb170 | 1598 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 1599 | memset(sig, 0, sizeof(pdkim_signature)); |
80a47a2c | 1600 | |
3045f050 | 1601 | sig->bodylength = -1; |
80a47a2c | 1602 | |
3045f050 | 1603 | ctx->mode = PDKIM_MODE_SIGN; |
3045f050 | 1604 | ctx->sig = sig; |
80a47a2c | 1605 | |
e2e3255a JH |
1606 | sig->domain = string_copy(US domain); |
1607 | sig->selector = string_copy(US selector); | |
1608 | sig->rsa_privkey = string_copy(US rsa_privkey); | |
2592e6c0 | 1609 | sig->algo = algo; |
cb224393 | 1610 | |
1ed59855 | 1611 | exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); |
3045f050 | 1612 | return ctx; |
6ab02e3f | 1613 | } |
80a47a2c | 1614 | |
f444c2c7 | 1615 | |
80a47a2c | 1616 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
1617 | |
1618 | DLLEXPORT int | |
1619 | pdkim_set_optional(pdkim_ctx *ctx, | |
80a47a2c TK |
1620 | char *sign_headers, |
1621 | char *identity, | |
1622 | int canon_headers, | |
1623 | int canon_body, | |
1624 | long bodylength, | |
80a47a2c | 1625 | unsigned long created, |
3045f050 JH |
1626 | unsigned long expires) |
1627 | { | |
8ef02a06 JH |
1628 | pdkim_signature * sig = ctx->sig; |
1629 | ||
3045f050 | 1630 | if (identity) |
e2e3255a | 1631 | sig->identity = string_copy(US identity); |
80a47a2c | 1632 | |
ca9cb170 JH |
1633 | sig->sign_headers = string_copy(sign_headers |
1634 | ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS); | |
80a47a2c | 1635 | |
8ef02a06 JH |
1636 | sig->canon_headers = canon_headers; |
1637 | sig->canon_body = canon_body; | |
1638 | sig->bodylength = bodylength; | |
1639 | sig->created = created; | |
1640 | sig->expires = expires; | |
80a47a2c | 1641 | |
3045f050 | 1642 | return PDKIM_OK; |
6ab02e3f | 1643 | } |
3045f050 | 1644 | |
3045f050 | 1645 | |
2592e6c0 JH |
1646 | void |
1647 | pdkim_init(void) | |
1648 | { | |
1649 | exim_rsa_init(); | |
1650 | } | |
1651 | ||
1652 | ||
1653 | ||
f444c2c7 | 1654 | #endif /*DISABLE_DKIM*/ |