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 | { | |
f7302073 JH |
118 | switch(status) |
119 | { | |
120 | case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE"; | |
121 | case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID"; | |
122 | case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL"; | |
123 | case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS"; | |
124 | default: return "PDKIM_VERIFY_UNKNOWN"; | |
ff7ddfd7 TK |
125 | } |
126 | } | |
f444c2c7 JH |
127 | |
128 | const char * | |
129 | pdkim_verify_ext_status_str(int ext_status) | |
130 | { | |
f7302073 JH |
131 | switch(ext_status) |
132 | { | |
133 | case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY"; | |
134 | case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE"; | |
135 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE"; | |
136 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE"; | |
137 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD"; | |
138 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT"; | |
139 | case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: return "PDKIM_VERIFY_INVALID_SIGNATURE_ERROR"; | |
140 | case PDKIM_VERIFY_INVALID_DKIM_VERSION: return "PDKIM_VERIFY_INVALID_DKIM_VERSION"; | |
141 | default: return "PDKIM_VERIFY_UNKNOWN"; | |
142 | } | |
143 | } | |
144 | ||
145 | const char * | |
146 | pdkim_errstr(int status) | |
147 | { | |
148 | switch(status) | |
149 | { | |
150 | case PDKIM_OK: return "OK"; | |
151 | case PDKIM_FAIL: return "FAIL"; | |
152 | case PDKIM_ERR_RSA_PRIVKEY: return "RSA_PRIVKEY"; | |
153 | case PDKIM_ERR_RSA_SIGNING: return "RSA SIGNING"; | |
154 | case PDKIM_ERR_LONG_LINE: return "RSA_LONG_LINE"; | |
155 | case PDKIM_ERR_BUFFER_TOO_SMALL: return "BUFFER_TOO_SMALL"; | |
156 | case PDKIM_SIGN_PRIVKEY_WRAP: return "PRIVKEY_WRAP"; | |
157 | case PDKIM_SIGN_PRIVKEY_B64D: return "PRIVKEY_B64D"; | |
158 | default: return "(unknown)"; | |
ff7ddfd7 TK |
159 | } |
160 | } | |
161 | ||
162 | ||
80a47a2c TK |
163 | /* -------------------------------------------------------------------------- */ |
164 | /* Print debugging functions */ | |
2592e6c0 | 165 | static void |
b78006ac | 166 | pdkim_quoteprint(const uschar *data, int len) |
3045f050 JH |
167 | { |
168 | int i; | |
0d04a285 | 169 | for (i = 0; i < len; i++) |
3045f050 | 170 | { |
b78006ac | 171 | const int c = data[i]; |
3045f050 JH |
172 | switch (c) |
173 | { | |
0d04a285 JH |
174 | case ' ' : debug_printf("{SP}"); break; |
175 | case '\t': debug_printf("{TB}"); break; | |
176 | case '\r': debug_printf("{CR}"); break; | |
177 | case '\n': debug_printf("{LF}"); break; | |
178 | case '{' : debug_printf("{BO}"); break; | |
179 | case '}' : debug_printf("{BC}"); break; | |
3045f050 JH |
180 | default: |
181 | if ( (c < 32) || (c > 127) ) | |
0d04a285 | 182 | debug_printf("{%02x}", c); |
3045f050 | 183 | else |
0d04a285 | 184 | debug_printf("%c", c); |
80a47a2c TK |
185 | break; |
186 | } | |
187 | } | |
2592e6c0 | 188 | debug_printf("\n"); |
80a47a2c | 189 | } |
80a47a2c | 190 | |
2592e6c0 | 191 | static void |
b78006ac | 192 | pdkim_hexprint(const uschar *data, int len) |
3045f050 JH |
193 | { |
194 | int i; | |
b78006ac | 195 | for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]); |
2592e6c0 | 196 | debug_printf("\n"); |
80a47a2c | 197 | } |
80a47a2c TK |
198 | |
199 | ||
f444c2c7 | 200 | |
f444c2c7 | 201 | static pdkim_stringlist * |
ca9cb170 | 202 | pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str) |
3045f050 | 203 | { |
ca9cb170 | 204 | pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist)); |
3045f050 | 205 | |
abe1010c | 206 | memset(new_entry, 0, sizeof(pdkim_stringlist)); |
ca9cb170 | 207 | new_entry->value = string_copy(str); |
ab9152ff JH |
208 | if (base) new_entry->next = base; |
209 | return new_entry; | |
6ab02e3f | 210 | } |
80a47a2c TK |
211 | |
212 | ||
8ef02a06 JH |
213 | |
214 | /* Trim whitespace fore & aft */ | |
215 | ||
ca9cb170 JH |
216 | static void |
217 | pdkim_strtrim(uschar * str) | |
3045f050 | 218 | { |
ca9cb170 JH |
219 | uschar * p = str; |
220 | uschar * q = str; | |
8ef02a06 JH |
221 | while (*p == '\t' || *p == ' ') p++; /* skip whitespace */ |
222 | while (*p) {*q = *p; q++; p++;} /* dump the leading whitespace */ | |
3045f050 | 223 | *q = '\0'; |
ca9cb170 | 224 | while (q != str && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) ) |
8ef02a06 | 225 | { /* dump trailing whitespace */ |
80a47a2c | 226 | *q = '\0'; |
3045f050 | 227 | q--; |
80a47a2c | 228 | } |
8ef02a06 JH |
229 | } |
230 | ||
231 | ||
80a47a2c | 232 | |
80a47a2c | 233 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
234 | |
235 | DLLEXPORT void | |
236 | pdkim_free_ctx(pdkim_ctx *ctx) | |
237 | { | |
6ab02e3f | 238 | } |
80a47a2c TK |
239 | |
240 | ||
241 | /* -------------------------------------------------------------------------- */ | |
242 | /* Matches the name of the passed raw "header" against | |
8ef02a06 JH |
243 | the passed colon-separated "tick", and invalidates |
244 | the entry in tick. Returns OK or fail-code */ | |
245 | /*XXX might be safer done using a pdkim_stringlist for "tick" */ | |
3045f050 | 246 | |
f444c2c7 | 247 | static int |
e2e3255a | 248 | header_name_match(const uschar * header, uschar * tick) |
3045f050 | 249 | { |
ca9cb170 JH |
250 | uschar * hname; |
251 | uschar * lcopy; | |
252 | uschar * p; | |
253 | uschar * q; | |
254 | uschar * hcolon = Ustrchr(header, ':'); /* Get header name */ | |
3045f050 | 255 | |
ca9cb170 JH |
256 | if (!hcolon) |
257 | return PDKIM_FAIL; /* This isn't a header */ | |
3045f050 | 258 | |
ca9cb170 JH |
259 | /* if we had strncmpic() we wouldn't need this copy */ |
260 | hname = string_copyn(header, hcolon-header); | |
3045f050 JH |
261 | |
262 | /* Copy tick-off list locally, so we can punch zeroes into it */ | |
ca9cb170 JH |
263 | p = lcopy = string_copy(tick); |
264 | ||
265 | for (q = Ustrchr(p, ':'); q; q = Ustrchr(p, ':')) | |
3045f050 JH |
266 | { |
267 | *q = '\0'; | |
ca9cb170 JH |
268 | if (strcmpic(p, hname) == 0) |
269 | goto found; | |
80a47a2c | 270 | |
3045f050 | 271 | p = q+1; |
80a47a2c TK |
272 | } |
273 | ||
ca9cb170 JH |
274 | if (strcmpic(p, hname) == 0) |
275 | goto found; | |
276 | ||
277 | return PDKIM_FAIL; | |
278 | ||
279 | found: | |
3045f050 | 280 | /* Invalidate header name instance in tick-off list */ |
8ef02a06 | 281 | tick[p-lcopy] = '_'; |
ca9cb170 | 282 | return PDKIM_OK; |
80a47a2c TK |
283 | } |
284 | ||
285 | ||
286 | /* -------------------------------------------------------------------------- */ | |
ca9cb170 | 287 | /* Performs "relaxed" canonicalization of a header. */ |
3045f050 | 288 | |
ca9cb170 JH |
289 | static uschar * |
290 | pdkim_relax_header(const uschar * header, int crlf) | |
3045f050 JH |
291 | { |
292 | BOOL past_field_name = FALSE; | |
293 | BOOL seen_wsp = FALSE; | |
ca9cb170 JH |
294 | const uschar * p; |
295 | uschar * relaxed = store_get(Ustrlen(header)+3); | |
296 | uschar * q = relaxed; | |
3045f050 | 297 | |
ca9cb170 | 298 | for (p = header; *p; p++) |
3045f050 | 299 | { |
ca9cb170 | 300 | uschar c = *p; |
3045f050 JH |
301 | /* Ignore CR & LF */ |
302 | if (c == '\r' || c == '\n') | |
303 | continue; | |
304 | if (c == '\t' || c == ' ') | |
305 | { | |
306 | if (seen_wsp) | |
80a47a2c | 307 | continue; |
3045f050 JH |
308 | c = ' '; /* Turns WSP into SP */ |
309 | seen_wsp = TRUE; | |
80a47a2c | 310 | } |
3045f050 JH |
311 | else |
312 | if (!past_field_name && c == ':') | |
313 | { | |
314 | if (seen_wsp) q--; /* This removes WSP before the colon */ | |
315 | seen_wsp = TRUE; /* This removes WSP after the colon */ | |
316 | past_field_name = TRUE; | |
80a47a2c | 317 | } |
3045f050 JH |
318 | else |
319 | seen_wsp = FALSE; | |
320 | ||
321 | /* Lowercase header name */ | |
322 | if (!past_field_name) c = tolower(c); | |
323 | *q++ = c; | |
80a47a2c | 324 | } |
3045f050 JH |
325 | |
326 | if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */ | |
3045f050 | 327 | |
ca9cb170 JH |
328 | if (crlf) { *q++ = '\r'; *q++ = '\n'; } |
329 | *q = '\0'; | |
3045f050 | 330 | return relaxed; |
6ab02e3f | 331 | } |
80a47a2c TK |
332 | |
333 | ||
334 | /* -------------------------------------------------------------------------- */ | |
335 | #define PDKIM_QP_ERROR_DECODE -1 | |
3045f050 | 336 | |
e2e3255a JH |
337 | static uschar * |
338 | pdkim_decode_qp_char(uschar *qp_p, int *c) | |
3045f050 | 339 | { |
e2e3255a | 340 | uschar *initial_pos = qp_p; |
3045f050 JH |
341 | |
342 | /* Advance one char */ | |
343 | qp_p++; | |
344 | ||
345 | /* Check for two hex digits and decode them */ | |
346 | if (isxdigit(*qp_p) && isxdigit(qp_p[1])) | |
347 | { | |
348 | /* Do hex conversion */ | |
349 | *c = (isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10) << 4; | |
a5840e10 | 350 | *c |= isdigit(qp_p[1]) ? qp_p[1] - '0' : toupper(qp_p[1]) - 'A' + 10; |
3045f050 | 351 | return qp_p + 2; |
6ab02e3f | 352 | } |
80a47a2c | 353 | |
3045f050 JH |
354 | /* Illegal char here */ |
355 | *c = PDKIM_QP_ERROR_DECODE; | |
356 | return initial_pos; | |
80a47a2c TK |
357 | } |
358 | ||
359 | ||
360 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 361 | |
e2e3255a | 362 | static uschar * |
ca9cb170 | 363 | pdkim_decode_qp(uschar * str) |
3045f050 JH |
364 | { |
365 | int nchar = 0; | |
ca9cb170 JH |
366 | uschar * q; |
367 | uschar * p = str; | |
368 | uschar * n = store_get(Ustrlen(str)+1); | |
3045f050 JH |
369 | |
370 | *n = '\0'; | |
371 | q = n; | |
ca9cb170 | 372 | while (*p) |
3045f050 JH |
373 | { |
374 | if (*p == '=') | |
375 | { | |
376 | p = pdkim_decode_qp_char(p, &nchar); | |
377 | if (nchar >= 0) | |
378 | { | |
379 | *q++ = nchar; | |
380 | continue; | |
80a47a2c TK |
381 | } |
382 | } | |
3045f050 JH |
383 | else |
384 | *q++ = *p; | |
385 | p++; | |
80a47a2c | 386 | } |
3045f050 JH |
387 | *q = '\0'; |
388 | return n; | |
80a47a2c TK |
389 | } |
390 | ||
391 | ||
392 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 393 | |
2592e6c0 JH |
394 | static void |
395 | pdkim_decode_base64(uschar *str, blob * b) | |
3045f050 | 396 | { |
2592e6c0 | 397 | int dlen; |
2592e6c0 JH |
398 | dlen = b64decode(str, &b->data); |
399 | if (dlen < 0) b->data = NULL; | |
400 | b->len = dlen; | |
80a47a2c TK |
401 | } |
402 | ||
ca9cb170 | 403 | static uschar * |
2592e6c0 | 404 | pdkim_encode_base64(blob * b) |
3045f050 | 405 | { |
ca9cb170 | 406 | return b64encode(b->data, b->len); |
80a47a2c TK |
407 | } |
408 | ||
409 | ||
410 | /* -------------------------------------------------------------------------- */ | |
411 | #define PDKIM_HDR_LIMBO 0 | |
412 | #define PDKIM_HDR_TAG 1 | |
413 | #define PDKIM_HDR_VALUE 2 | |
3045f050 | 414 | |
f444c2c7 | 415 | static pdkim_signature * |
ca9cb170 | 416 | pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr) |
3045f050 JH |
417 | { |
418 | pdkim_signature *sig ; | |
ca9cb170 JH |
419 | uschar *p, *q; |
420 | uschar * cur_tag = NULL; int ts = 0, tl = 0; | |
421 | uschar * cur_val = NULL; int vs = 0, vl = 0; | |
3045f050 JH |
422 | BOOL past_hname = FALSE; |
423 | BOOL in_b_val = FALSE; | |
424 | int where = PDKIM_HDR_LIMBO; | |
425 | int i; | |
426 | ||
ca9cb170 | 427 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 428 | memset(sig, 0, sizeof(pdkim_signature)); |
3045f050 JH |
429 | sig->bodylength = -1; |
430 | ||
07eeb4df | 431 | /* Set so invalid/missing data error display is accurate */ |
432 | sig->algo = -1; | |
433 | sig->version = 0; | |
434 | ||
ca9cb170 | 435 | q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1); |
80a47a2c | 436 | |
3045f050 JH |
437 | for (p = raw_hdr; ; p++) |
438 | { | |
439 | char c = *p; | |
80a47a2c | 440 | |
3045f050 JH |
441 | /* Ignore FWS */ |
442 | if (c == '\r' || c == '\n') | |
443 | goto NEXT_CHAR; | |
80a47a2c | 444 | |
3045f050 JH |
445 | /* Fast-forward through header name */ |
446 | if (!past_hname) | |
447 | { | |
448 | if (c == ':') past_hname = TRUE; | |
449 | goto NEXT_CHAR; | |
80a47a2c TK |
450 | } |
451 | ||
3045f050 JH |
452 | if (where == PDKIM_HDR_LIMBO) |
453 | { | |
454 | /* In limbo, just wait for a tag-char to appear */ | |
455 | if (!(c >= 'a' && c <= 'z')) | |
456 | goto NEXT_CHAR; | |
80a47a2c | 457 | |
3045f050 | 458 | where = PDKIM_HDR_TAG; |
80a47a2c TK |
459 | } |
460 | ||
3045f050 JH |
461 | if (where == PDKIM_HDR_TAG) |
462 | { | |
3045f050 | 463 | if (c >= 'a' && c <= 'z') |
c2f669a4 | 464 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); |
80a47a2c | 465 | |
3045f050 JH |
466 | if (c == '=') |
467 | { | |
ca9cb170 JH |
468 | cur_tag[tl] = '\0'; |
469 | if (Ustrcmp(cur_tag, "b") == 0) | |
3045f050 | 470 | { |
ca9cb170 | 471 | *q++ = '='; |
3045f050 JH |
472 | in_b_val = TRUE; |
473 | } | |
474 | where = PDKIM_HDR_VALUE; | |
475 | goto NEXT_CHAR; | |
80a47a2c TK |
476 | } |
477 | } | |
478 | ||
3045f050 JH |
479 | if (where == PDKIM_HDR_VALUE) |
480 | { | |
3045f050 JH |
481 | if (c == '\r' || c == '\n' || c == ' ' || c == '\t') |
482 | goto NEXT_CHAR; | |
483 | ||
484 | if (c == ';' || c == '\0') | |
485 | { | |
ca9cb170 | 486 | if (tl && vl) |
3045f050 | 487 | { |
ca9cb170 | 488 | cur_val[vl] = '\0'; |
3045f050 JH |
489 | pdkim_strtrim(cur_val); |
490 | ||
ca9cb170 | 491 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); |
3045f050 | 492 | |
ca9cb170 | 493 | switch (*cur_tag) |
3045f050 JH |
494 | { |
495 | case 'b': | |
ca9cb170 JH |
496 | if (cur_tag[1] == 'h') |
497 | pdkim_decode_base64(cur_val, &sig->bodyhash); | |
3045f050 | 498 | else |
ca9cb170 | 499 | pdkim_decode_base64(cur_val, &sig->sigdata); |
3045f050 JH |
500 | break; |
501 | case 'v': | |
502 | /* We only support version 1, and that is currently the | |
503 | only version there is. */ | |
07eeb4df | 504 | sig->version = |
505 | Ustrcmp(cur_val, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1; | |
3045f050 JH |
506 | break; |
507 | case 'a': | |
508 | for (i = 0; pdkim_algos[i]; i++) | |
ca9cb170 | 509 | if (Ustrcmp(cur_val, pdkim_algos[i]) == 0) |
3045f050 JH |
510 | { |
511 | sig->algo = i; | |
512 | break; | |
513 | } | |
514 | break; | |
515 | case 'c': | |
516 | for (i = 0; pdkim_combined_canons[i].str; i++) | |
ca9cb170 | 517 | if (Ustrcmp(cur_val, pdkim_combined_canons[i].str) == 0) |
3045f050 JH |
518 | { |
519 | sig->canon_headers = pdkim_combined_canons[i].canon_headers; | |
520 | sig->canon_body = pdkim_combined_canons[i].canon_body; | |
521 | break; | |
522 | } | |
523 | break; | |
524 | case 'q': | |
525 | for (i = 0; pdkim_querymethods[i]; i++) | |
ca9cb170 | 526 | if (Ustrcmp(cur_val, pdkim_querymethods[i]) == 0) |
3045f050 JH |
527 | { |
528 | sig->querymethod = i; | |
529 | break; | |
530 | } | |
531 | break; | |
532 | case 's': | |
ca9cb170 | 533 | sig->selector = string_copy(cur_val); break; |
3045f050 | 534 | case 'd': |
ca9cb170 | 535 | sig->domain = string_copy(cur_val); break; |
3045f050 | 536 | case 'i': |
ca9cb170 | 537 | sig->identity = pdkim_decode_qp(cur_val); break; |
3045f050 | 538 | case 't': |
ca9cb170 | 539 | sig->created = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 540 | case 'x': |
ca9cb170 | 541 | sig->expires = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 542 | case 'l': |
ca9cb170 | 543 | sig->bodylength = strtol(CS cur_val, NULL, 10); break; |
3045f050 | 544 | case 'h': |
ca9cb170 | 545 | sig->headernames = string_copy(cur_val); break; |
3045f050 | 546 | case 'z': |
ca9cb170 | 547 | sig->copiedheaders = pdkim_decode_qp(cur_val); break; |
3045f050 | 548 | default: |
0d04a285 | 549 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); |
3045f050 JH |
550 | break; |
551 | } | |
552 | } | |
ca9cb170 JH |
553 | tl = 0; |
554 | vl = 0; | |
3045f050 JH |
555 | in_b_val = FALSE; |
556 | where = PDKIM_HDR_LIMBO; | |
80a47a2c | 557 | } |
3045f050 | 558 | else |
c2f669a4 | 559 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); |
80a47a2c TK |
560 | } |
561 | ||
3045f050 JH |
562 | NEXT_CHAR: |
563 | if (c == '\0') | |
564 | break; | |
80a47a2c | 565 | |
3045f050 JH |
566 | if (!in_b_val) |
567 | *q++ = c; | |
80a47a2c TK |
568 | } |
569 | ||
3045f050 JH |
570 | *q = '\0'; |
571 | /* Chomp raw header. The final newline must not be added to the signature. */ | |
37f3dc43 JH |
572 | while (--q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n')) |
573 | *q = '\0'; | |
80a47a2c | 574 | |
0d04a285 | 575 | DEBUG(D_acl) |
3045f050 | 576 | { |
0d04a285 | 577 | debug_printf( |
3045f050 | 578 | "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 579 | pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val)); |
0d04a285 | 580 | debug_printf( |
b78006ac | 581 | "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sigdata.len*8); |
0d04a285 | 582 | debug_printf( |
3045f050 | 583 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 584 | } |
80a47a2c | 585 | |
1ed59855 | 586 | exim_sha_init(&sig->body_hash, sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); |
3045f050 | 587 | return sig; |
80a47a2c TK |
588 | } |
589 | ||
590 | ||
591 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 592 | |
f444c2c7 | 593 | static pdkim_pubkey * |
e2e3255a | 594 | pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record) |
3045f050 JH |
595 | { |
596 | pdkim_pubkey *pub; | |
e2e3255a | 597 | const uschar *p; |
ca9cb170 JH |
598 | uschar * cur_tag = NULL; int ts = 0, tl = 0; |
599 | uschar * cur_val = NULL; int vs = 0, vl = 0; | |
3045f050 | 600 | int where = PDKIM_HDR_LIMBO; |
80a47a2c | 601 | |
ca9cb170 | 602 | pub = store_get(sizeof(pdkim_pubkey)); |
abe1010c | 603 | memset(pub, 0, sizeof(pdkim_pubkey)); |
80a47a2c | 604 | |
3045f050 | 605 | for (p = raw_record; ; p++) |
3045f050 | 606 | { |
e21a4d00 | 607 | uschar c = *p; |
80a47a2c | 608 | |
e21a4d00 JH |
609 | /* Ignore FWS */ |
610 | if (c != '\r' && c != '\n') switch (where) | |
3045f050 | 611 | { |
e21a4d00 JH |
612 | case PDKIM_HDR_LIMBO: /* In limbo, just wait for a tag-char to appear */ |
613 | if (!(c >= 'a' && c <= 'z')) | |
614 | break; | |
615 | where = PDKIM_HDR_TAG; | |
616 | /*FALLTHROUGH*/ | |
80a47a2c | 617 | |
e21a4d00 JH |
618 | case PDKIM_HDR_TAG: |
619 | if (c >= 'a' && c <= 'z') | |
620 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); | |
3045f050 | 621 | |
e21a4d00 | 622 | if (c == '=') |
3045f050 | 623 | { |
e21a4d00 JH |
624 | cur_tag[tl] = '\0'; |
625 | where = PDKIM_HDR_VALUE; | |
3045f050 | 626 | } |
e21a4d00 JH |
627 | break; |
628 | ||
629 | case PDKIM_HDR_VALUE: | |
630 | if (c == ';' || c == '\0') | |
631 | { | |
632 | if (tl && vl) | |
633 | { | |
634 | cur_val[vl] = '\0'; | |
635 | pdkim_strtrim(cur_val); | |
636 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); | |
637 | ||
638 | switch (cur_tag[0]) | |
639 | { | |
640 | case 'v': | |
641 | pub->version = string_copy(cur_val); break; | |
642 | case 'h': | |
643 | case 'k': | |
644 | /* This field appears to never be used. Also, unclear why | |
645 | a 'k' (key-type_ would go in this field name. There is a field | |
646 | "keytype", also never used. | |
647 | pub->hashes = string_copy(cur_val); | |
648 | */ | |
649 | break; | |
650 | case 'g': | |
651 | pub->granularity = string_copy(cur_val); break; | |
652 | case 'n': | |
653 | pub->notes = pdkim_decode_qp(cur_val); break; | |
654 | case 'p': | |
655 | pdkim_decode_base64(US cur_val, &pub->key); break; | |
656 | case 's': | |
657 | pub->srvtype = string_copy(cur_val); break; | |
658 | case 't': | |
659 | if (Ustrchr(cur_val, 'y') != NULL) pub->testing = 1; | |
660 | if (Ustrchr(cur_val, 's') != NULL) pub->no_subdomaining = 1; | |
661 | break; | |
662 | default: | |
663 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); | |
664 | break; | |
665 | } | |
666 | } | |
667 | tl = 0; | |
668 | vl = 0; | |
669 | where = PDKIM_HDR_LIMBO; | |
670 | } | |
671 | else | |
672 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); | |
673 | break; | |
80a47a2c | 674 | } |
80a47a2c | 675 | |
e21a4d00 JH |
676 | if (c == '\0') break; |
677 | } | |
80a47a2c | 678 | |
3045f050 | 679 | /* Set fallback defaults */ |
ca9cb170 | 680 | if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION); |
e21a4d00 JH |
681 | else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0) return NULL; |
682 | ||
ca9cb170 | 683 | if (!pub->granularity) pub->granularity = string_copy(US"*"); |
e21a4d00 | 684 | /* |
e2e3255a | 685 | if (!pub->keytype ) pub->keytype = string_copy(US"rsa"); |
e21a4d00 | 686 | */ |
ca9cb170 | 687 | if (!pub->srvtype ) pub->srvtype = string_copy(US"*"); |
80a47a2c | 688 | |
3045f050 | 689 | /* p= is required */ |
2592e6c0 | 690 | if (pub->key.data) |
80a47a2c | 691 | return pub; |
3045f050 | 692 | |
3045f050 | 693 | return NULL; |
80a47a2c TK |
694 | } |
695 | ||
696 | ||
697 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 698 | |
f444c2c7 | 699 | static int |
3045f050 JH |
700 | pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len) |
701 | { | |
702 | pdkim_signature *sig = ctx->sig; | |
703 | /* Cache relaxed version of data */ | |
b78006ac JH |
704 | uschar *relaxed_data = NULL; |
705 | int relaxed_len = 0; | |
3045f050 JH |
706 | |
707 | /* Traverse all signatures, updating their hashes. */ | |
708 | while (sig) | |
709 | { | |
710 | /* Defaults to simple canon (no further treatment necessary) */ | |
b78006ac JH |
711 | const uschar *canon_data = CUS data; |
712 | int canon_len = len; | |
3045f050 JH |
713 | |
714 | if (sig->canon_body == PDKIM_CANON_RELAXED) | |
715 | { | |
716 | /* Relax the line if not done already */ | |
717 | if (!relaxed_data) | |
718 | { | |
719 | BOOL seen_wsp = FALSE; | |
720 | const char *p; | |
721 | int q = 0; | |
722 | ||
d5bccfc8 JH |
723 | /* We want to be able to free this else we allocate |
724 | for the entire message which could be many MB. Since | |
725 | we don't know what allocations the SHA routines might | |
726 | do, not safe to use store_get()/store_reset(). */ | |
727 | ||
40c90bca | 728 | relaxed_data = store_malloc(len+1); |
3045f050 JH |
729 | |
730 | for (p = data; *p; p++) | |
731 | { | |
732 | char c = *p; | |
733 | if (c == '\r') | |
734 | { | |
735 | if (q > 0 && relaxed_data[q-1] == ' ') | |
736 | q--; | |
737 | } | |
738 | else if (c == '\t' || c == ' ') | |
739 | { | |
740 | c = ' '; /* Turns WSP into SP */ | |
741 | if (seen_wsp) | |
742 | continue; | |
743 | seen_wsp = TRUE; | |
744 | } | |
745 | else | |
746 | seen_wsp = FALSE; | |
747 | relaxed_data[q++] = c; | |
748 | } | |
749 | relaxed_data[q] = '\0'; | |
750 | relaxed_len = q; | |
80a47a2c | 751 | } |
3045f050 JH |
752 | canon_data = relaxed_data; |
753 | canon_len = relaxed_len; | |
80a47a2c TK |
754 | } |
755 | ||
3045f050 JH |
756 | /* Make sure we don't exceed the to-be-signed body length */ |
757 | if ( sig->bodylength >= 0 | |
758 | && sig->signed_body_bytes + (unsigned long)canon_len > sig->bodylength | |
759 | ) | |
760 | canon_len = sig->bodylength - sig->signed_body_bytes; | |
80a47a2c | 761 | |
3045f050 JH |
762 | if (canon_len > 0) |
763 | { | |
e2e3255a | 764 | exim_sha_update(&sig->body_hash, CUS canon_data, canon_len); |
3045f050 | 765 | sig->signed_body_bytes += canon_len; |
2592e6c0 | 766 | DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len); |
80a47a2c TK |
767 | } |
768 | ||
3045f050 | 769 | sig = sig->next; |
80a47a2c TK |
770 | } |
771 | ||
40c90bca | 772 | if (relaxed_data) store_free(relaxed_data); |
3045f050 | 773 | return PDKIM_OK; |
6ab02e3f | 774 | } |
80a47a2c TK |
775 | |
776 | ||
777 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 778 | |
ca9cb170 | 779 | static void |
3045f050 JH |
780 | pdkim_finish_bodyhash(pdkim_ctx *ctx) |
781 | { | |
f4d091fb | 782 | pdkim_signature *sig; |
80a47a2c | 783 | |
3045f050 | 784 | /* Traverse all signatures */ |
f4d091fb | 785 | for (sig = ctx->sig; sig; sig = sig->next) |
3045f050 | 786 | { /* Finish hashes */ |
2592e6c0 JH |
787 | blob bh; |
788 | ||
789 | exim_sha_finish(&sig->body_hash, &bh); | |
3045f050 | 790 | |
0d04a285 | 791 | DEBUG(D_acl) |
3045f050 | 792 | { |
0d04a285 | 793 | debug_printf("PDKIM [%s] Body bytes hashed: %lu\n" |
e21a4d00 | 794 | "PDKIM [%s] Body hash computed: ", |
0d04a285 | 795 | sig->domain, sig->signed_body_bytes, sig->domain); |
b78006ac | 796 | pdkim_hexprint(CUS bh.data, bh.len); |
80a47a2c | 797 | } |
3045f050 JH |
798 | |
799 | /* SIGNING -------------------------------------------------------------- */ | |
e983e85a | 800 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 801 | { |
2592e6c0 | 802 | sig->bodyhash = bh; |
3045f050 JH |
803 | |
804 | /* If bodylength limit is set, and we have received less bytes | |
805 | than the requested amount, effectively remove the limit tag. */ | |
806 | if (sig->signed_body_bytes < sig->bodylength) | |
807 | sig->bodylength = -1; | |
80a47a2c | 808 | } |
3045f050 JH |
809 | |
810 | /* VERIFICATION --------------------------------------------------------- */ | |
811 | else | |
812 | { | |
813 | /* Compare bodyhash */ | |
2592e6c0 | 814 | if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) |
3045f050 | 815 | { |
0d04a285 | 816 | DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain); |
80a47a2c | 817 | } |
3045f050 JH |
818 | else |
819 | { | |
0d04a285 | 820 | DEBUG(D_acl) |
3045f050 | 821 | { |
e21a4d00 | 822 | debug_printf("PDKIM [%s] Body hash signature from headers: ", sig->domain); |
2592e6c0 JH |
823 | pdkim_hexprint(sig->bodyhash.data, |
824 | exim_sha_hashlen(&sig->body_hash)); | |
0d04a285 | 825 | debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain); |
3045f050 | 826 | } |
3045f050 JH |
827 | sig->verify_status = PDKIM_VERIFY_FAIL; |
828 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; | |
80a47a2c TK |
829 | } |
830 | } | |
80a47a2c | 831 | } |
6ab02e3f | 832 | } |
80a47a2c TK |
833 | |
834 | ||
835 | ||
e983e85a JH |
836 | static int |
837 | pdkim_body_complete(pdkim_ctx * ctx) | |
838 | { | |
839 | pdkim_signature * sig = ctx->sig; /*XXX assumes only one sig */ | |
840 | ||
841 | /* In simple body mode, if any empty lines were buffered, | |
842 | replace with one. rfc 4871 3.4.3 */ | |
843 | /*XXX checking the signed-body-bytes is a gross hack; I think | |
844 | it indicates that all linebreaks should be buffered, including | |
845 | the one terminating a text line */ | |
846 | ||
847 | if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE | |
848 | && sig->signed_body_bytes == 0 | |
849 | && ctx->num_buffered_crlf > 0 | |
850 | ) | |
851 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
852 | ||
853 | ctx->flags |= PDKIM_SEEN_EOD; | |
854 | ctx->linebuf_offset = 0; | |
855 | return PDKIM_OK; | |
856 | } | |
857 | ||
858 | ||
859 | ||
80a47a2c | 860 | /* -------------------------------------------------------------------------- */ |
e983e85a | 861 | /* Call from pdkim_feed below for processing complete body lines */ |
3045f050 | 862 | |
0d04a285 | 863 | static int |
3045f050 JH |
864 | pdkim_bodyline_complete(pdkim_ctx *ctx) |
865 | { | |
866 | char *p = ctx->linebuf; | |
867 | int n = ctx->linebuf_offset; | |
c14470c3 | 868 | pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */ |
3045f050 JH |
869 | |
870 | /* Ignore extra data if we've seen the end-of-data marker */ | |
e983e85a | 871 | if (ctx->flags & PDKIM_SEEN_EOD) goto BAIL; |
3045f050 JH |
872 | |
873 | /* We've always got one extra byte to stuff a zero ... */ | |
0d04a285 | 874 | ctx->linebuf[ctx->linebuf_offset] = '\0'; |
3045f050 | 875 | |
0d04a285 | 876 | /* Terminate on EOD marker */ |
e983e85a | 877 | if (ctx->flags & PDKIM_DOT_TERM) |
3045f050 | 878 | { |
e983e85a JH |
879 | if ( memcmp(p, ".\r\n", 3) == 0) |
880 | return pdkim_body_complete(ctx); | |
0d04a285 | 881 | |
e983e85a JH |
882 | /* Unstuff dots */ |
883 | if (memcmp(p, "..", 2) == 0) | |
884 | { | |
885 | p++; | |
886 | n--; | |
887 | } | |
80a47a2c TK |
888 | } |
889 | ||
3045f050 JH |
890 | /* Empty lines need to be buffered until we find a non-empty line */ |
891 | if (memcmp(p, "\r\n", 2) == 0) | |
892 | { | |
893 | ctx->num_buffered_crlf++; | |
894 | goto BAIL; | |
80a47a2c TK |
895 | } |
896 | ||
c14470c3 | 897 | if (sig && sig->canon_body == PDKIM_CANON_RELAXED) |
3045f050 JH |
898 | { |
899 | /* Lines with just spaces need to be buffered too */ | |
900 | char *check = p; | |
901 | while (memcmp(check, "\r\n", 2) != 0) | |
902 | { | |
903 | char c = *check; | |
6a11a9e6 | 904 | |
3045f050 JH |
905 | if (c != '\t' && c != ' ') |
906 | goto PROCESS; | |
907 | check++; | |
6a11a9e6 JH |
908 | } |
909 | ||
3045f050 JH |
910 | ctx->num_buffered_crlf++; |
911 | goto BAIL; | |
912 | } | |
6a11a9e6 | 913 | |
3045f050 JH |
914 | PROCESS: |
915 | /* At this point, we have a non-empty line, so release the buffered ones. */ | |
916 | while (ctx->num_buffered_crlf) | |
917 | { | |
918 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
919 | ctx->num_buffered_crlf--; | |
80a47a2c TK |
920 | } |
921 | ||
3045f050 | 922 | pdkim_update_bodyhash(ctx, p, n); |
80a47a2c | 923 | |
3045f050 JH |
924 | BAIL: |
925 | ctx->linebuf_offset = 0; | |
926 | return PDKIM_OK; | |
80a47a2c TK |
927 | } |
928 | ||
929 | ||
930 | /* -------------------------------------------------------------------------- */ | |
931 | /* Callback from pdkim_feed below for processing complete headers */ | |
932 | #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" | |
3045f050 | 933 | |
f444c2c7 | 934 | static int |
3045f050 JH |
935 | pdkim_header_complete(pdkim_ctx *ctx) |
936 | { | |
3045f050 | 937 | /* Special case: The last header can have an extra \r appended */ |
ca9cb170 JH |
938 | if ( (ctx->cur_header_len > 1) && |
939 | (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') ) | |
940 | --ctx->cur_header_len; | |
941 | ctx->cur_header[ctx->cur_header_len] = '\0'; | |
80a47a2c | 942 | |
3045f050 JH |
943 | ctx->num_headers++; |
944 | if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; | |
80a47a2c | 945 | |
3045f050 | 946 | /* SIGNING -------------------------------------------------------------- */ |
e983e85a | 947 | if (ctx->flags & PDKIM_MODE_SIGN) |
0d04a285 JH |
948 | { |
949 | pdkim_signature *sig; | |
950 | ||
951 | for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */ | |
80a47a2c | 952 | |
ab9152ff | 953 | /* Add header to the signed headers list (in reverse order) */ |
ca9cb170 JH |
954 | sig->headers = pdkim_prepend_stringlist(sig->headers, |
955 | ctx->cur_header); | |
0d04a285 | 956 | } |
94431adb | 957 | |
0d04a285 | 958 | /* VERIFICATION ----------------------------------------------------------- */ |
3045f050 | 959 | /* DKIM-Signature: headers are added to the verification list */ |
e983e85a | 960 | else |
3045f050 | 961 | { |
e2e3255a | 962 | if (strncasecmp(CCS ctx->cur_header, |
3045f050 | 963 | DKIM_SIGNATURE_HEADERNAME, |
e2e3255a | 964 | Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0) |
3045f050 JH |
965 | { |
966 | pdkim_signature *new_sig; | |
80a47a2c | 967 | |
3045f050 | 968 | /* Create and chain new signature block */ |
0d04a285 | 969 | DEBUG(D_acl) debug_printf( |
3045f050 | 970 | "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 | 971 | |
ca9cb170 | 972 | if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header))) |
3045f050 JH |
973 | { |
974 | pdkim_signature *last_sig = ctx->sig; | |
975 | if (!last_sig) | |
976 | ctx->sig = new_sig; | |
977 | else | |
978 | { | |
979 | while (last_sig->next) last_sig = last_sig->next; | |
980 | last_sig->next = new_sig; | |
981 | } | |
80a47a2c | 982 | } |
abe1010c | 983 | else |
0d04a285 JH |
984 | DEBUG(D_acl) debug_printf( |
985 | "Error while parsing signature header\n" | |
3045f050 | 986 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 987 | } |
37f8b554 | 988 | |
3045f050 JH |
989 | /* every other header is stored for signature verification */ |
990 | else | |
ca9cb170 | 991 | ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); |
80a47a2c TK |
992 | } |
993 | ||
3045f050 | 994 | BAIL: |
ca9cb170 JH |
995 | *ctx->cur_header = '\0'; |
996 | ctx->cur_header_len = 0; /* leave buffer for reuse */ | |
3045f050 | 997 | return PDKIM_OK; |
6ab02e3f | 998 | } |
80a47a2c TK |
999 | |
1000 | ||
1001 | ||
1002 | /* -------------------------------------------------------------------------- */ | |
1003 | #define HEADER_BUFFER_FRAG_SIZE 256 | |
3045f050 JH |
1004 | |
1005 | DLLEXPORT int | |
ca9cb170 | 1006 | pdkim_feed(pdkim_ctx *ctx, char *data, int len) |
3045f050 JH |
1007 | { |
1008 | int p; | |
1009 | ||
e983e85a JH |
1010 | /* Alternate EOD signal, used in non-dotstuffing mode */ |
1011 | if (!data) | |
1012 | pdkim_body_complete(ctx); | |
1013 | ||
10c50704 | 1014 | else for (p = 0; p<len; p++) |
3045f050 | 1015 | { |
ca9cb170 | 1016 | uschar c = data[p]; |
3045f050 | 1017 | |
e983e85a | 1018 | if (ctx->flags & PDKIM_PAST_HDRS) |
3045f050 JH |
1019 | { |
1020 | /* Processing body byte */ | |
0d04a285 | 1021 | ctx->linebuf[ctx->linebuf_offset++] = c; |
3045f050 JH |
1022 | if (c == '\n') |
1023 | { | |
1024 | int rc = pdkim_bodyline_complete(ctx); /* End of line */ | |
1025 | if (rc != PDKIM_OK) return rc; | |
80a47a2c | 1026 | } |
3045f050 JH |
1027 | if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1)) |
1028 | return PDKIM_ERR_LONG_LINE; | |
80a47a2c | 1029 | } |
3045f050 JH |
1030 | else |
1031 | { | |
1032 | /* Processing header byte */ | |
1033 | if (c != '\r') | |
1034 | { | |
1035 | if (c == '\n') | |
1036 | { | |
e983e85a | 1037 | if (ctx->flags & PDKIM_SEEN_LF) |
3045f050 JH |
1038 | { |
1039 | int rc = pdkim_header_complete(ctx); /* Seen last header line */ | |
1040 | if (rc != PDKIM_OK) return rc; | |
1041 | ||
e983e85a | 1042 | ctx->flags = ctx->flags & ~PDKIM_SEEN_LF | PDKIM_PAST_HDRS; |
0d04a285 | 1043 | DEBUG(D_acl) debug_printf( |
8ef02a06 | 1044 | "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 JH |
1045 | continue; |
1046 | } | |
1047 | else | |
e983e85a | 1048 | ctx->flags |= PDKIM_SEEN_LF; |
3045f050 | 1049 | } |
e983e85a | 1050 | else if (ctx->flags & PDKIM_SEEN_LF) |
3045f050 JH |
1051 | { |
1052 | if (!(c == '\t' || c == ' ')) | |
1053 | { | |
1054 | int rc = pdkim_header_complete(ctx); /* End of header */ | |
1055 | if (rc != PDKIM_OK) return rc; | |
1056 | } | |
e983e85a | 1057 | ctx->flags &= ~PDKIM_SEEN_LF; |
3045f050 | 1058 | } |
80a47a2c | 1059 | } |
3045f050 | 1060 | |
ca9cb170 | 1061 | if (ctx->cur_header_len < PDKIM_MAX_HEADER_LEN) |
c2f669a4 | 1062 | ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, |
e2e3255a | 1063 | &ctx->cur_header_len, CUS &data[p], 1); |
80a47a2c TK |
1064 | } |
1065 | } | |
3045f050 | 1066 | return PDKIM_OK; |
6ab02e3f | 1067 | } |
80a47a2c | 1068 | |
ca9cb170 JH |
1069 | |
1070 | ||
1071 | /* Extend a grwong header with a continuation-linebreak */ | |
1072 | static uschar * | |
1073 | pdkim_hdr_cont(uschar * str, int * size, int * ptr, int * col) | |
1074 | { | |
1075 | *col = 1; | |
c2f669a4 | 1076 | return string_catn(str, size, ptr, US"\r\n\t", 3); |
ca9cb170 JH |
1077 | } |
1078 | ||
1079 | ||
1080 | ||
05b7d6de JB |
1081 | /* |
1082 | * RFC 5322 specifies that header line length SHOULD be no more than 78 | |
1083 | * lets make it so! | |
1084 | * pdkim_headcat | |
ca9cb170 JH |
1085 | * |
1086 | * returns uschar * (not nul-terminated) | |
05b7d6de JB |
1087 | * |
1088 | * col: this int holds and receives column number (octets since last '\n') | |
1089 | * str: partial string to append to | |
ca9cb170 JH |
1090 | * size: current buffer size for str |
1091 | * ptr: current tail-pointer for str | |
94431adb | 1092 | * pad: padding, split line or space after before or after eg: ";" |
05b7d6de JB |
1093 | * intro: - must join to payload eg "h=", usually the tag name |
1094 | * payload: eg base64 data - long data can be split arbitrarily. | |
1095 | * | |
1096 | * this code doesn't fold the header in some of the places that RFC4871 | |
1097 | * allows: As per RFC5322(2.2.3) it only folds before or after tag-value | |
1098 | * pairs and inside long values. it also always spaces or breaks after the | |
94431adb | 1099 | * "pad" |
05b7d6de JB |
1100 | * |
1101 | * no guarantees are made for output given out-of range input. like tag | |
f444c2c7 | 1102 | * names longer than 78, or bogus col. Input is assumed to be free of line breaks. |
05b7d6de JB |
1103 | */ |
1104 | ||
ca9cb170 JH |
1105 | static uschar * |
1106 | pdkim_headcat(int * col, uschar * str, int * size, int * ptr, | |
1107 | const uschar * pad, const uschar * intro, const uschar * payload) | |
3045f050 JH |
1108 | { |
1109 | size_t l; | |
1110 | ||
1111 | if (pad) | |
05b7d6de | 1112 | { |
ca9cb170 | 1113 | l = Ustrlen(pad); |
3045f050 | 1114 | if (*col + l > 78) |
ca9cb170 | 1115 | str = pdkim_hdr_cont(str, size, ptr, col); |
c2f669a4 | 1116 | str = string_catn(str, size, ptr, pad, l); |
3045f050 | 1117 | *col += l; |
05b7d6de JB |
1118 | } |
1119 | ||
ca9cb170 | 1120 | l = (pad?1:0) + (intro?Ustrlen(intro):0); |
05b7d6de | 1121 | |
3045f050 | 1122 | if (*col + l > 78) |
05b7d6de | 1123 | { /*can't fit intro - start a new line to make room.*/ |
ca9cb170 JH |
1124 | str = pdkim_hdr_cont(str, size, ptr, col); |
1125 | l = intro?Ustrlen(intro):0; | |
05b7d6de JB |
1126 | } |
1127 | ||
ca9cb170 | 1128 | l += payload ? Ustrlen(payload):0 ; |
05b7d6de | 1129 | |
3045f050 | 1130 | while (l>77) |
05b7d6de | 1131 | { /* this fragment will not fit on a single line */ |
3045f050 | 1132 | if (pad) |
05b7d6de | 1133 | { |
c2f669a4 | 1134 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1135 | *col += 1; |
1136 | pad = NULL; /* only want this once */ | |
1137 | l--; | |
05b7d6de | 1138 | } |
3045f050 JH |
1139 | |
1140 | if (intro) | |
05b7d6de | 1141 | { |
ca9cb170 | 1142 | size_t sl = Ustrlen(intro); |
3045f050 | 1143 | |
c2f669a4 | 1144 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1145 | *col += sl; |
1146 | l -= sl; | |
1147 | intro = NULL; /* only want this once */ | |
05b7d6de | 1148 | } |
3045f050 JH |
1149 | |
1150 | if (payload) | |
05b7d6de | 1151 | { |
ca9cb170 | 1152 | size_t sl = Ustrlen(payload); |
3045f050 JH |
1153 | size_t chomp = *col+sl < 77 ? sl : 78-*col; |
1154 | ||
c2f669a4 | 1155 | str = string_catn(str, size, ptr, payload, chomp); |
3045f050 JH |
1156 | *col += chomp; |
1157 | payload += chomp; | |
1158 | l -= chomp-1; | |
05b7d6de | 1159 | } |
3045f050 JH |
1160 | |
1161 | /* the while precondition tells us it didn't fit. */ | |
ca9cb170 | 1162 | str = pdkim_hdr_cont(str, size, ptr, col); |
05b7d6de | 1163 | } |
3045f050 JH |
1164 | |
1165 | if (*col + l > 78) | |
05b7d6de | 1166 | { |
ca9cb170 | 1167 | str = pdkim_hdr_cont(str, size, ptr, col); |
3045f050 | 1168 | pad = NULL; |
05b7d6de JB |
1169 | } |
1170 | ||
3045f050 | 1171 | if (pad) |
05b7d6de | 1172 | { |
c2f669a4 | 1173 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1174 | *col += 1; |
1175 | pad = NULL; | |
05b7d6de JB |
1176 | } |
1177 | ||
3045f050 | 1178 | if (intro) |
05b7d6de | 1179 | { |
ca9cb170 | 1180 | size_t sl = Ustrlen(intro); |
3045f050 | 1181 | |
c2f669a4 | 1182 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1183 | *col += sl; |
1184 | l -= sl; | |
1185 | intro = NULL; | |
05b7d6de | 1186 | } |
3045f050 JH |
1187 | |
1188 | if (payload) | |
05b7d6de | 1189 | { |
ca9cb170 | 1190 | size_t sl = Ustrlen(payload); |
3045f050 | 1191 | |
c2f669a4 | 1192 | str = string_catn(str, size, ptr, payload, sl); |
3045f050 | 1193 | *col += sl; |
05b7d6de JB |
1194 | } |
1195 | ||
ca9cb170 | 1196 | return str; |
05b7d6de | 1197 | } |
80a47a2c | 1198 | |
3045f050 | 1199 | |
80a47a2c | 1200 | /* -------------------------------------------------------------------------- */ |
3045f050 | 1201 | |
ca9cb170 | 1202 | static uschar * |
2592e6c0 | 1203 | pdkim_create_header(pdkim_signature *sig, BOOL final) |
3045f050 | 1204 | { |
ca9cb170 JH |
1205 | uschar * base64_bh; |
1206 | uschar * base64_b; | |
3045f050 | 1207 | int col = 0; |
ca9cb170 JH |
1208 | uschar * hdr; int hdr_size = 0, hdr_len = 0; |
1209 | uschar * canon_all; int can_size = 0, can_len = 0; | |
3045f050 | 1210 | |
c2f669a4 JH |
1211 | canon_all = string_cat (NULL, &can_size, &can_len, |
1212 | pdkim_canons[sig->canon_headers]); | |
1213 | canon_all = string_catn(canon_all, &can_size, &can_len, US"/", 1); | |
1214 | canon_all = string_cat (canon_all, &can_size, &can_len, | |
1215 | pdkim_canons[sig->canon_body]); | |
ca9cb170 | 1216 | canon_all[can_len] = '\0'; |
3045f050 | 1217 | |
ca9cb170 | 1218 | hdr = string_cat(NULL, &hdr_size, &hdr_len, |
e2e3255a | 1219 | US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION); |
ca9cb170 | 1220 | col = hdr_len; |
3045f050 JH |
1221 | |
1222 | /* Required and static bits */ | |
ca9cb170 JH |
1223 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"a=", |
1224 | pdkim_algos[sig->algo]); | |
1225 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"q=", | |
1226 | pdkim_querymethods[sig->querymethod]); | |
1227 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"c=", | |
1228 | canon_all); | |
1229 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"d=", | |
1230 | sig->domain); | |
1231 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"s=", | |
1232 | sig->selector); | |
1233 | ||
1234 | /* list of header names can be split between items. */ | |
3045f050 | 1235 | { |
e2e3255a | 1236 | uschar * n = string_copy(sig->headernames); |
ca9cb170 JH |
1237 | uschar * i = US"h="; |
1238 | uschar * s = US";"; | |
1239 | ||
1240 | while (*n) | |
05b7d6de | 1241 | { |
ca9cb170 | 1242 | uschar * c = Ustrchr(n, ':'); |
3045f050 | 1243 | |
ca9cb170 | 1244 | if (c) *c ='\0'; |
05b7d6de | 1245 | |
ca9cb170 JH |
1246 | if (!i) |
1247 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, NULL, US":"); | |
05b7d6de | 1248 | |
ca9cb170 | 1249 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, s, i, n); |
3045f050 | 1250 | |
ca9cb170 JH |
1251 | if (!c) |
1252 | break; | |
3045f050 | 1253 | |
ca9cb170 JH |
1254 | n = c+1; |
1255 | s = NULL; | |
1256 | i = NULL; | |
80a47a2c | 1257 | } |
ca9cb170 | 1258 | } |
05b7d6de | 1259 | |
ca9cb170 JH |
1260 | base64_bh = pdkim_encode_base64(&sig->bodyhash); |
1261 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"bh=", base64_bh); | |
3045f050 | 1262 | |
ca9cb170 JH |
1263 | /* Optional bits */ |
1264 | if (sig->identity) | |
1265 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"i=", sig->identity); | |
3045f050 | 1266 | |
ca9cb170 JH |
1267 | if (sig->created > 0) |
1268 | { | |
e2e3255a | 1269 | uschar minibuf[20]; |
3045f050 | 1270 | |
e2e3255a | 1271 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created); |
ca9cb170 JH |
1272 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"t=", minibuf); |
1273 | } | |
3045f050 | 1274 | |
ca9cb170 JH |
1275 | if (sig->expires > 0) |
1276 | { | |
e2e3255a | 1277 | uschar minibuf[20]; |
3045f050 | 1278 | |
e2e3255a | 1279 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires); |
ca9cb170 JH |
1280 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"x=", minibuf); |
1281 | } | |
3045f050 | 1282 | |
ca9cb170 JH |
1283 | if (sig->bodylength >= 0) |
1284 | { | |
e2e3255a | 1285 | uschar minibuf[20]; |
80a47a2c | 1286 | |
e2e3255a | 1287 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength); |
ca9cb170 | 1288 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"l=", minibuf); |
3045f050 | 1289 | } |
05b7d6de | 1290 | |
ca9cb170 JH |
1291 | /* Preliminary or final version? */ |
1292 | base64_b = final ? pdkim_encode_base64(&sig->sigdata) : US""; | |
1293 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b); | |
80a47a2c | 1294 | |
ca9cb170 JH |
1295 | /* add trailing semicolon: I'm not sure if this is actually needed */ |
1296 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, US";", US""); | |
80a47a2c | 1297 | |
ca9cb170 JH |
1298 | hdr[hdr_len] = '\0'; |
1299 | return hdr; | |
80a47a2c TK |
1300 | } |
1301 | ||
1302 | ||
1303 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1304 | |
1305 | DLLEXPORT int | |
1306 | pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) | |
1307 | { | |
1308 | pdkim_signature *sig = ctx->sig; | |
3045f050 JH |
1309 | |
1310 | /* Check if we must still flush a (partial) header. If that is the | |
1311 | case, the message has no body, and we must compute a body hash | |
1312 | out of '<CR><LF>' */ | |
ca9cb170 | 1313 | if (ctx->cur_header && ctx->cur_header_len) |
3045f050 JH |
1314 | { |
1315 | int rc = pdkim_header_complete(ctx); | |
1316 | if (rc != PDKIM_OK) return rc; | |
1317 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
80a47a2c | 1318 | } |
3045f050 | 1319 | else |
0d04a285 | 1320 | DEBUG(D_acl) debug_printf( |
3045f050 | 1321 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1322 | |
3045f050 | 1323 | /* Build (and/or evaluate) body hash */ |
ca9cb170 | 1324 | pdkim_finish_bodyhash(ctx); |
80a47a2c | 1325 | |
3045f050 JH |
1326 | while (sig) |
1327 | { | |
2592e6c0 JH |
1328 | BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1; |
1329 | hctx hhash_ctx; | |
ad6f5499 | 1330 | uschar * sig_hdr = US""; |
2592e6c0 JH |
1331 | blob hhash; |
1332 | blob hdata; | |
cb224393 | 1333 | int hdata_alloc = 0; |
cb224393 | 1334 | |
2592e6c0 JH |
1335 | hdata.data = NULL; |
1336 | hdata.len = 0; | |
1337 | ||
1ed59855 | 1338 | exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256); |
80a47a2c | 1339 | |
0d04a285 | 1340 | DEBUG(D_acl) debug_printf( |
e21a4d00 | 1341 | "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>>>\n"); |
3045f050 JH |
1342 | |
1343 | /* SIGNING ---------------------------------------------------------------- */ | |
1344 | /* When signing, walk through our header list and add them to the hash. As we | |
8ef02a06 JH |
1345 | go, construct a list of the header's names to use for the h= parameter. |
1346 | Then append to that list any remaining header names for which there was no | |
1347 | header to sign. */ | |
3045f050 | 1348 | |
e983e85a | 1349 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1350 | { |
10c50704 JH |
1351 | uschar * headernames = NULL; /* Collected signed header names */ |
1352 | int hs = 0, hl = 0; | |
3045f050 | 1353 | pdkim_stringlist *p; |
8ef02a06 JH |
1354 | const uschar * l; |
1355 | uschar * s; | |
1356 | int sep = 0; | |
3045f050 JH |
1357 | |
1358 | for (p = sig->headers; p; p = p->next) | |
ab9152ff JH |
1359 | if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK) |
1360 | { | |
1361 | uschar * rh; | |
1362 | /* Collect header names (Note: colon presence is guaranteed here) */ | |
1363 | uschar * q = Ustrchr(p->value, ':'); | |
3045f050 | 1364 | |
c2f669a4 | 1365 | headernames = string_catn(headernames, &hs, &hl, |
ca9cb170 | 1366 | p->value, (q - US p->value) + (p->next ? 1 : 0)); |
3045f050 | 1367 | |
ab9152ff | 1368 | rh = sig->canon_headers == PDKIM_CANON_RELAXED |
ca9cb170 JH |
1369 | ? pdkim_relax_header(p->value, 1) /* cook header for relaxed canon */ |
1370 | : string_copy(CUS p->value); /* just copy it for simple canon */ | |
3045f050 | 1371 | |
ab9152ff | 1372 | /* Feed header to the hash algorithm */ |
e2e3255a | 1373 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); |
f444c2c7 | 1374 | |
ab9152ff JH |
1375 | /* Remember headers block for signing (when the library cannot do incremental) */ |
1376 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, rh); | |
3045f050 | 1377 | |
ab9152ff JH |
1378 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); |
1379 | } | |
8ef02a06 | 1380 | |
ca9cb170 | 1381 | l = sig->sign_headers; |
8ef02a06 JH |
1382 | while((s = string_nextinlist(&l, &sep, NULL, 0))) |
1383 | if (*s != '_') | |
ab9152ff | 1384 | { /*SSS string_append_listele() */ |
ca9cb170 | 1385 | if (hl > 0 && headernames[hl-1] != ':') |
c2f669a4 | 1386 | headernames = string_catn(headernames, &hs, &hl, US":", 1); |
ca9cb170 | 1387 | |
c2f669a4 | 1388 | headernames = string_cat(headernames, &hs, &hl, s); |
8ef02a06 | 1389 | } |
ca9cb170 JH |
1390 | headernames[hl] = '\0'; |
1391 | ||
1392 | /* Copy headernames to signature struct */ | |
1393 | sig->headernames = headernames; | |
ca9cb170 JH |
1394 | |
1395 | /* Create signature header with b= omitted */ | |
1396 | sig_hdr = pdkim_create_header(sig, FALSE); | |
80a47a2c | 1397 | } |
37f8b554 | 1398 | |
3045f050 JH |
1399 | /* VERIFICATION ----------------------------------------------------------- */ |
1400 | /* When verifying, walk through the header name list in the h= parameter and | |
1401 | add the headers to the hash in that order. */ | |
1402 | else | |
1403 | { | |
10c50704 | 1404 | uschar * p = sig->headernames; |
2592e6c0 JH |
1405 | uschar * q; |
1406 | pdkim_stringlist * hdrs; | |
3045f050 | 1407 | |
10c50704 | 1408 | if (p) |
3045f050 | 1409 | { |
10c50704 | 1410 | /* clear tags */ |
3045f050 | 1411 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) |
10c50704 | 1412 | hdrs->tag = 0; |
3045f050 | 1413 | |
10c50704 JH |
1414 | p = string_copy(p); |
1415 | while(1) | |
1416 | { | |
1417 | if ((q = Ustrchr(p, ':'))) | |
1418 | *q = '\0'; | |
1419 | ||
1420 | /*XXX walk the list of headers in same order as received. */ | |
1421 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) | |
1422 | if ( hdrs->tag == 0 | |
4dc2379a | 1423 | && strncasecmp(CCS hdrs->value, CCS p, Ustrlen(p)) == 0 |
10c50704 JH |
1424 | && (hdrs->value)[Ustrlen(p)] == ':' |
1425 | ) | |
1426 | { | |
1427 | /* cook header for relaxed canon, or just copy it for simple */ | |
1428 | ||
1429 | uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED | |
1430 | ? pdkim_relax_header(hdrs->value, 1) | |
1431 | : string_copy(CUS hdrs->value); | |
1432 | ||
1433 | /* Feed header to the hash algorithm */ | |
1434 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); | |
1435 | ||
1436 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); | |
1437 | hdrs->tag = 1; | |
1438 | break; | |
1439 | } | |
3045f050 | 1440 | |
10c50704 JH |
1441 | if (!q) break; |
1442 | p = q+1; | |
1443 | } | |
3045f050 | 1444 | |
10c50704 | 1445 | sig_hdr = string_copy(sig->rawsig_no_b_val); |
80a47a2c | 1446 | } |
80a47a2c TK |
1447 | } |
1448 | ||
0d04a285 | 1449 | DEBUG(D_acl) debug_printf( |
3045f050 | 1450 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1451 | |
3045f050 JH |
1452 | /* Relax header if necessary */ |
1453 | if (sig->canon_headers == PDKIM_CANON_RELAXED) | |
ca9cb170 | 1454 | sig_hdr = pdkim_relax_header(sig_hdr, 0); |
80a47a2c | 1455 | |
0d04a285 | 1456 | DEBUG(D_acl) |
3045f050 | 1457 | { |
0d04a285 | 1458 | debug_printf( |
3045f050 | 1459 | "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 1460 | pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr)); |
0d04a285 | 1461 | debug_printf( |
3045f050 | 1462 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1463 | } |
3045f050 JH |
1464 | |
1465 | /* Finalize header hash */ | |
e2e3255a | 1466 | exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr)); |
2592e6c0 | 1467 | exim_sha_finish(&hhash_ctx, &hhash); |
3045f050 | 1468 | |
f444c2c7 JH |
1469 | DEBUG(D_acl) |
1470 | { | |
e21a4d00 | 1471 | debug_printf("PDKIM [%s] Header hash computed: ", sig->domain); |
2592e6c0 | 1472 | pdkim_hexprint(hhash.data, hhash.len); |
80a47a2c TK |
1473 | } |
1474 | ||
2592e6c0 | 1475 | /* Remember headers block for signing (when the library cannot do incremental) */ |
e983e85a | 1476 | if (ctx->flags & PDKIM_MODE_SIGN) |
b78006ac | 1477 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, US sig_hdr); |
f444c2c7 | 1478 | |
3045f050 | 1479 | /* SIGNING ---------------------------------------------------------------- */ |
e983e85a | 1480 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1481 | { |
2592e6c0 JH |
1482 | es_ctx sctx; |
1483 | const uschar * errstr; | |
f444c2c7 JH |
1484 | |
1485 | /* Import private key */ | |
b78006ac | 1486 | if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &sctx))) |
f444c2c7 | 1487 | { |
2592e6c0 | 1488 | DEBUG(D_acl) debug_printf("signing_init: %s\n", errstr); |
f444c2c7 JH |
1489 | return PDKIM_ERR_RSA_PRIVKEY; |
1490 | } | |
80a47a2c | 1491 | |
2592e6c0 JH |
1492 | /* Do signing. With OpenSSL we are signing the hash of headers just |
1493 | calculated, with GnuTLS we have to sign an entire block of headers | |
1494 | (due to available interfaces) and it recalculates the hash internally. */ | |
f444c2c7 | 1495 | |
2592e6c0 JH |
1496 | #if defined(RSA_OPENSSL) || defined(RSA_GCRYPT) |
1497 | hdata = hhash; | |
f444c2c7 JH |
1498 | #endif |
1499 | ||
2592e6c0 | 1500 | if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata))) |
f444c2c7 | 1501 | { |
2592e6c0 | 1502 | DEBUG(D_acl) debug_printf("signing: %s\n", errstr); |
f444c2c7 JH |
1503 | return PDKIM_ERR_RSA_SIGNING; |
1504 | } | |
80a47a2c | 1505 | |
0d04a285 | 1506 | DEBUG(D_acl) |
3045f050 | 1507 | { |
0d04a285 | 1508 | debug_printf( "PDKIM [%s] b computed: ", sig->domain); |
2592e6c0 | 1509 | pdkim_hexprint(sig->sigdata.data, sig->sigdata.len); |
80a47a2c | 1510 | } |
80a47a2c | 1511 | |
ca9cb170 | 1512 | sig->signature_header = pdkim_create_header(sig, TRUE); |
80a47a2c | 1513 | } |
80a47a2c | 1514 | |
3045f050 JH |
1515 | /* VERIFICATION ----------------------------------------------------------- */ |
1516 | else | |
1517 | { | |
2592e6c0 JH |
1518 | ev_ctx vctx; |
1519 | const uschar * errstr; | |
e21a4d00 | 1520 | pdkim_pubkey * p; |
3045f050 | 1521 | |
ca9cb170 | 1522 | uschar *dns_txt_name, *dns_txt_reply; |
f444c2c7 | 1523 | |
07eeb4df | 1524 | /* Make sure we have all required signature tags */ |
1525 | if (!( sig->domain && *sig->domain | |
1526 | && sig->selector && *sig->selector | |
1527 | && sig->headernames && *sig->headernames | |
1528 | && sig->bodyhash.data | |
1529 | && sig->sigdata.data | |
1530 | && sig->algo > -1 | |
1531 | && sig->version | |
1532 | ) ) | |
1533 | { | |
1534 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1535 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR; | |
1536 | ||
1537 | DEBUG(D_acl) debug_printf( | |
1538 | " Error in DKIM-Signature header: tags missing or invalid\n" | |
1539 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1540 | goto NEXT_VERIFY; | |
1541 | } | |
1542 | ||
1543 | /* Make sure sig uses supported DKIM version (only v1) */ | |
1544 | if (sig->version != 1) | |
1545 | { | |
1546 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1547 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION; | |
1548 | ||
1549 | DEBUG(D_acl) debug_printf( | |
1550 | " Error in DKIM-Signature header: unsupported DKIM version\n" | |
1551 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1552 | goto NEXT_VERIFY; | |
1553 | } | |
1554 | ||
f444c2c7 | 1555 | /* Fetch public key for signing domain, from DNS */ |
3045f050 | 1556 | |
ca9cb170 JH |
1557 | dns_txt_name = string_sprintf("%s._domainkey.%s.", |
1558 | sig->selector, sig->domain); | |
80a47a2c | 1559 | |
ca9cb170 | 1560 | dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1561 | memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1562 | |
ca9cb170 | 1563 | if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK |
3045f050 JH |
1564 | || dns_txt_reply[0] == '\0') |
1565 | { | |
1566 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1567 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE; | |
1568 | goto NEXT_VERIFY; | |
80a47a2c TK |
1569 | } |
1570 | ||
0d04a285 | 1571 | DEBUG(D_acl) |
3045f050 | 1572 | { |
0d04a285 | 1573 | debug_printf( |
2592e6c0 JH |
1574 | "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" |
1575 | " Raw record: "); | |
ca9cb170 | 1576 | pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply)); |
80a47a2c | 1577 | } |
3045f050 | 1578 | |
e21a4d00 JH |
1579 | if ( !(p = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply)) |
1580 | || (Ustrcmp(p->srvtype, "*") != 0 && Ustrcmp(p->srvtype, "email") != 0) | |
1581 | ) | |
3045f050 JH |
1582 | { |
1583 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
df3def24 | 1584 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD; |
3045f050 | 1585 | |
e21a4d00 JH |
1586 | DEBUG(D_acl) |
1587 | { | |
1588 | if (p) | |
1589 | debug_printf(" Invalid public key service type '%s'\n", p->srvtype); | |
1590 | else | |
1591 | debug_printf(" Error while parsing public key record\n"); | |
1592 | debug_printf( | |
3045f050 | 1593 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
e21a4d00 | 1594 | } |
3045f050 | 1595 | goto NEXT_VERIFY; |
80a47a2c | 1596 | } |
e21a4d00 | 1597 | sig->pubkey = p; |
80a47a2c | 1598 | |
0d04a285 | 1599 | DEBUG(D_acl) debug_printf( |
2592e6c0 | 1600 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
3045f050 | 1601 | |
f444c2c7 | 1602 | /* Import public key */ |
2592e6c0 | 1603 | if ((errstr = exim_rsa_verify_init(&sig->pubkey->key, &vctx))) |
3045f050 | 1604 | { |
2592e6c0 | 1605 | DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr); |
3045f050 | 1606 | sig->verify_status = PDKIM_VERIFY_INVALID; |
df3def24 | 1607 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; |
3045f050 | 1608 | goto NEXT_VERIFY; |
80a47a2c TK |
1609 | } |
1610 | ||
3045f050 | 1611 | /* Check the signature */ |
2592e6c0 | 1612 | if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata))) |
3045f050 | 1613 | { |
2592e6c0 | 1614 | DEBUG(D_acl) debug_printf("headers verify: %s\n", errstr); |
3045f050 JH |
1615 | sig->verify_status = PDKIM_VERIFY_FAIL; |
1616 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; | |
1617 | goto NEXT_VERIFY; | |
ff7ddfd7 TK |
1618 | } |
1619 | ||
2592e6c0 | 1620 | |
3045f050 JH |
1621 | /* We have a winner! (if bodydhash was correct earlier) */ |
1622 | if (sig->verify_status == PDKIM_VERIFY_NONE) | |
1623 | sig->verify_status = PDKIM_VERIFY_PASS; | |
1624 | ||
1625 | NEXT_VERIFY: | |
1626 | ||
0d04a285 | 1627 | DEBUG(D_acl) |
3045f050 | 1628 | { |
0d04a285 | 1629 | debug_printf("PDKIM [%s] signature status: %s", |
3045f050 JH |
1630 | sig->domain, pdkim_verify_status_str(sig->verify_status)); |
1631 | if (sig->verify_ext_status > 0) | |
0d04a285 | 1632 | debug_printf(" (%s)\n", |
3045f050 JH |
1633 | pdkim_verify_ext_status_str(sig->verify_ext_status)); |
1634 | else | |
0d04a285 | 1635 | debug_printf("\n"); |
80a47a2c | 1636 | } |
80a47a2c TK |
1637 | } |
1638 | ||
3045f050 | 1639 | sig = sig->next; |
80a47a2c TK |
1640 | } |
1641 | ||
3045f050 JH |
1642 | /* If requested, set return pointer to signature(s) */ |
1643 | if (return_signatures) | |
1644 | *return_signatures = ctx->sig; | |
80a47a2c | 1645 | |
3045f050 | 1646 | return PDKIM_OK; |
80a47a2c TK |
1647 | } |
1648 | ||
1649 | ||
1650 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1651 | |
1652 | DLLEXPORT pdkim_ctx * | |
e983e85a | 1653 | pdkim_init_verify(int(*dns_txt_callback)(char *, char *), BOOL dot_stuffing) |
3045f050 | 1654 | { |
ca9cb170 | 1655 | pdkim_ctx * ctx; |
3045f050 | 1656 | |
ca9cb170 | 1657 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1658 | memset(ctx, 0, sizeof(pdkim_ctx)); |
3045f050 | 1659 | |
e983e85a | 1660 | if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM; |
ca9cb170 | 1661 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
3045f050 | 1662 | ctx->dns_txt_callback = dns_txt_callback; |
80a47a2c | 1663 | |
3045f050 | 1664 | return ctx; |
80a47a2c TK |
1665 | } |
1666 | ||
1667 | ||
1668 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 1669 | |
3045f050 | 1670 | DLLEXPORT pdkim_ctx * |
e983e85a JH |
1671 | pdkim_init_sign(char *domain, char *selector, char *rsa_privkey, int algo, |
1672 | BOOL dot_stuffed) | |
3045f050 JH |
1673 | { |
1674 | pdkim_ctx *ctx; | |
1675 | pdkim_signature *sig; | |
80a47a2c | 1676 | |
3045f050 JH |
1677 | if (!domain || !selector || !rsa_privkey) |
1678 | return NULL; | |
80a47a2c | 1679 | |
ca9cb170 | 1680 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1681 | memset(ctx, 0, sizeof(pdkim_ctx)); |
80a47a2c | 1682 | |
e983e85a | 1683 | ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN; |
ca9cb170 | 1684 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
80a47a2c | 1685 | |
ca9cb170 | 1686 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 1687 | memset(sig, 0, sizeof(pdkim_signature)); |
80a47a2c | 1688 | |
3045f050 | 1689 | sig->bodylength = -1; |
3045f050 | 1690 | ctx->sig = sig; |
80a47a2c | 1691 | |
e2e3255a JH |
1692 | sig->domain = string_copy(US domain); |
1693 | sig->selector = string_copy(US selector); | |
1694 | sig->rsa_privkey = string_copy(US rsa_privkey); | |
2592e6c0 | 1695 | sig->algo = algo; |
cb224393 | 1696 | |
1ed59855 | 1697 | exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); |
3045f050 | 1698 | return ctx; |
6ab02e3f | 1699 | } |
80a47a2c | 1700 | |
f444c2c7 | 1701 | |
80a47a2c | 1702 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
1703 | |
1704 | DLLEXPORT int | |
1705 | pdkim_set_optional(pdkim_ctx *ctx, | |
80a47a2c TK |
1706 | char *sign_headers, |
1707 | char *identity, | |
1708 | int canon_headers, | |
1709 | int canon_body, | |
1710 | long bodylength, | |
80a47a2c | 1711 | unsigned long created, |
3045f050 JH |
1712 | unsigned long expires) |
1713 | { | |
8ef02a06 JH |
1714 | pdkim_signature * sig = ctx->sig; |
1715 | ||
3045f050 | 1716 | if (identity) |
e2e3255a | 1717 | sig->identity = string_copy(US identity); |
80a47a2c | 1718 | |
ca9cb170 JH |
1719 | sig->sign_headers = string_copy(sign_headers |
1720 | ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS); | |
80a47a2c | 1721 | |
8ef02a06 JH |
1722 | sig->canon_headers = canon_headers; |
1723 | sig->canon_body = canon_body; | |
1724 | sig->bodylength = bodylength; | |
1725 | sig->created = created; | |
1726 | sig->expires = expires; | |
80a47a2c | 1727 | |
3045f050 | 1728 | return PDKIM_OK; |
6ab02e3f | 1729 | } |
3045f050 | 1730 | |
3045f050 | 1731 | |
2592e6c0 JH |
1732 | void |
1733 | pdkim_init(void) | |
1734 | { | |
1735 | exim_rsa_init(); | |
1736 | } | |
1737 | ||
1738 | ||
1739 | ||
f444c2c7 | 1740 | #endif /*DISABLE_DKIM*/ |