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 JH |
605 | for (p = raw_record; ; p++) |
606 | { | |
607 | char c = *p; | |
80a47a2c | 608 | |
3045f050 JH |
609 | /* Ignore FWS */ |
610 | if (c == '\r' || c == '\n') | |
611 | goto NEXT_CHAR; | |
80a47a2c | 612 | |
3045f050 JH |
613 | if (where == PDKIM_HDR_LIMBO) |
614 | { | |
615 | /* In limbo, just wait for a tag-char to appear */ | |
616 | if (!(c >= 'a' && c <= 'z')) | |
617 | goto NEXT_CHAR; | |
80a47a2c | 618 | |
3045f050 | 619 | where = PDKIM_HDR_TAG; |
80a47a2c TK |
620 | } |
621 | ||
3045f050 JH |
622 | if (where == PDKIM_HDR_TAG) |
623 | { | |
3045f050 | 624 | if (c >= 'a' && c <= 'z') |
c2f669a4 | 625 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); |
80a47a2c | 626 | |
3045f050 JH |
627 | if (c == '=') |
628 | { | |
ca9cb170 | 629 | cur_tag[tl] = '\0'; |
3045f050 JH |
630 | where = PDKIM_HDR_VALUE; |
631 | goto NEXT_CHAR; | |
80a47a2c TK |
632 | } |
633 | } | |
634 | ||
3045f050 JH |
635 | if (where == PDKIM_HDR_VALUE) |
636 | { | |
3045f050 JH |
637 | if (c == ';' || c == '\0') |
638 | { | |
ca9cb170 | 639 | if (tl && vl) |
3045f050 | 640 | { |
ca9cb170 | 641 | cur_val[vl] = '\0'; |
3045f050 | 642 | pdkim_strtrim(cur_val); |
ca9cb170 | 643 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); |
3045f050 | 644 | |
ca9cb170 | 645 | switch (cur_tag[0]) |
3045f050 JH |
646 | { |
647 | case 'v': | |
648 | /* This tag isn't evaluated because: | |
649 | - We only support version DKIM1. | |
650 | - Which is the default for this value (set below) | |
651 | - Other versions are currently not specified. */ | |
652 | break; | |
653 | case 'h': | |
ca9cb170 JH |
654 | case 'k': |
655 | pub->hashes = string_copy(cur_val); break; | |
3045f050 | 656 | case 'g': |
ca9cb170 | 657 | pub->granularity = string_copy(cur_val); break; |
3045f050 | 658 | case 'n': |
ca9cb170 | 659 | pub->notes = pdkim_decode_qp(cur_val); break; |
3045f050 | 660 | case 'p': |
ca9cb170 | 661 | pdkim_decode_base64(US cur_val, &pub->key); |
2592e6c0 | 662 | break; |
3045f050 | 663 | case 's': |
ca9cb170 | 664 | pub->srvtype = string_copy(cur_val); break; |
3045f050 | 665 | case 't': |
e2e3255a JH |
666 | if (Ustrchr(cur_val, 'y') != NULL) pub->testing = 1; |
667 | if (Ustrchr(cur_val, 's') != NULL) pub->no_subdomaining = 1; | |
3045f050 JH |
668 | break; |
669 | default: | |
0d04a285 | 670 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); |
3045f050 JH |
671 | break; |
672 | } | |
673 | } | |
ca9cb170 JH |
674 | tl = 0; |
675 | vl = 0; | |
3045f050 | 676 | where = PDKIM_HDR_LIMBO; |
80a47a2c | 677 | } |
3045f050 | 678 | else |
c2f669a4 | 679 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); |
80a47a2c TK |
680 | } |
681 | ||
3045f050 JH |
682 | NEXT_CHAR: |
683 | if (c == '\0') break; | |
80a47a2c TK |
684 | } |
685 | ||
3045f050 | 686 | /* Set fallback defaults */ |
ca9cb170 JH |
687 | if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION); |
688 | if (!pub->granularity) pub->granularity = string_copy(US"*"); | |
e2e3255a | 689 | if (!pub->keytype ) pub->keytype = string_copy(US"rsa"); |
ca9cb170 | 690 | if (!pub->srvtype ) pub->srvtype = string_copy(US"*"); |
80a47a2c | 691 | |
3045f050 | 692 | /* p= is required */ |
2592e6c0 | 693 | if (pub->key.data) |
80a47a2c | 694 | return pub; |
3045f050 | 695 | |
3045f050 | 696 | return NULL; |
80a47a2c TK |
697 | } |
698 | ||
699 | ||
700 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 701 | |
f444c2c7 | 702 | static int |
3045f050 JH |
703 | pdkim_update_bodyhash(pdkim_ctx *ctx, const char *data, int len) |
704 | { | |
705 | pdkim_signature *sig = ctx->sig; | |
706 | /* Cache relaxed version of data */ | |
b78006ac JH |
707 | uschar *relaxed_data = NULL; |
708 | int relaxed_len = 0; | |
3045f050 JH |
709 | |
710 | /* Traverse all signatures, updating their hashes. */ | |
711 | while (sig) | |
712 | { | |
713 | /* Defaults to simple canon (no further treatment necessary) */ | |
b78006ac JH |
714 | const uschar *canon_data = CUS data; |
715 | int canon_len = len; | |
3045f050 JH |
716 | |
717 | if (sig->canon_body == PDKIM_CANON_RELAXED) | |
718 | { | |
719 | /* Relax the line if not done already */ | |
720 | if (!relaxed_data) | |
721 | { | |
722 | BOOL seen_wsp = FALSE; | |
723 | const char *p; | |
724 | int q = 0; | |
725 | ||
d5bccfc8 JH |
726 | /* We want to be able to free this else we allocate |
727 | for the entire message which could be many MB. Since | |
728 | we don't know what allocations the SHA routines might | |
729 | do, not safe to use store_get()/store_reset(). */ | |
730 | ||
731 | relaxed_data = malloc(len+1); | |
3045f050 JH |
732 | |
733 | for (p = data; *p; p++) | |
734 | { | |
735 | char c = *p; | |
736 | if (c == '\r') | |
737 | { | |
738 | if (q > 0 && relaxed_data[q-1] == ' ') | |
739 | q--; | |
740 | } | |
741 | else if (c == '\t' || c == ' ') | |
742 | { | |
743 | c = ' '; /* Turns WSP into SP */ | |
744 | if (seen_wsp) | |
745 | continue; | |
746 | seen_wsp = TRUE; | |
747 | } | |
748 | else | |
749 | seen_wsp = FALSE; | |
750 | relaxed_data[q++] = c; | |
751 | } | |
752 | relaxed_data[q] = '\0'; | |
753 | relaxed_len = q; | |
80a47a2c | 754 | } |
3045f050 JH |
755 | canon_data = relaxed_data; |
756 | canon_len = relaxed_len; | |
80a47a2c TK |
757 | } |
758 | ||
3045f050 JH |
759 | /* Make sure we don't exceed the to-be-signed body length */ |
760 | if ( sig->bodylength >= 0 | |
761 | && sig->signed_body_bytes + (unsigned long)canon_len > sig->bodylength | |
762 | ) | |
763 | canon_len = sig->bodylength - sig->signed_body_bytes; | |
80a47a2c | 764 | |
3045f050 JH |
765 | if (canon_len > 0) |
766 | { | |
e2e3255a | 767 | exim_sha_update(&sig->body_hash, CUS canon_data, canon_len); |
3045f050 | 768 | sig->signed_body_bytes += canon_len; |
2592e6c0 | 769 | DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len); |
80a47a2c TK |
770 | } |
771 | ||
3045f050 | 772 | sig = sig->next; |
80a47a2c TK |
773 | } |
774 | ||
d5bccfc8 | 775 | if (relaxed_data) free(relaxed_data); |
3045f050 | 776 | return PDKIM_OK; |
6ab02e3f | 777 | } |
80a47a2c TK |
778 | |
779 | ||
780 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 781 | |
ca9cb170 | 782 | static void |
3045f050 JH |
783 | pdkim_finish_bodyhash(pdkim_ctx *ctx) |
784 | { | |
f4d091fb | 785 | pdkim_signature *sig; |
80a47a2c | 786 | |
3045f050 | 787 | /* Traverse all signatures */ |
f4d091fb | 788 | for (sig = ctx->sig; sig; sig = sig->next) |
3045f050 | 789 | { /* Finish hashes */ |
2592e6c0 JH |
790 | blob bh; |
791 | ||
792 | exim_sha_finish(&sig->body_hash, &bh); | |
3045f050 | 793 | |
0d04a285 | 794 | DEBUG(D_acl) |
3045f050 | 795 | { |
0d04a285 JH |
796 | debug_printf("PDKIM [%s] Body bytes hashed: %lu\n" |
797 | "PDKIM [%s] bh computed: ", | |
798 | sig->domain, sig->signed_body_bytes, sig->domain); | |
b78006ac | 799 | pdkim_hexprint(CUS bh.data, bh.len); |
80a47a2c | 800 | } |
3045f050 JH |
801 | |
802 | /* SIGNING -------------------------------------------------------------- */ | |
e983e85a | 803 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 804 | { |
2592e6c0 | 805 | sig->bodyhash = bh; |
3045f050 JH |
806 | |
807 | /* If bodylength limit is set, and we have received less bytes | |
808 | than the requested amount, effectively remove the limit tag. */ | |
809 | if (sig->signed_body_bytes < sig->bodylength) | |
810 | sig->bodylength = -1; | |
80a47a2c | 811 | } |
3045f050 JH |
812 | |
813 | /* VERIFICATION --------------------------------------------------------- */ | |
814 | else | |
815 | { | |
816 | /* Compare bodyhash */ | |
2592e6c0 | 817 | if (memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) |
3045f050 | 818 | { |
0d04a285 | 819 | DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain); |
80a47a2c | 820 | } |
3045f050 JH |
821 | else |
822 | { | |
0d04a285 | 823 | DEBUG(D_acl) |
3045f050 | 824 | { |
0d04a285 | 825 | debug_printf("PDKIM [%s] bh signature: ", sig->domain); |
2592e6c0 JH |
826 | pdkim_hexprint(sig->bodyhash.data, |
827 | exim_sha_hashlen(&sig->body_hash)); | |
0d04a285 | 828 | debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain); |
3045f050 | 829 | } |
3045f050 JH |
830 | sig->verify_status = PDKIM_VERIFY_FAIL; |
831 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; | |
80a47a2c TK |
832 | } |
833 | } | |
80a47a2c | 834 | } |
6ab02e3f | 835 | } |
80a47a2c TK |
836 | |
837 | ||
838 | ||
e983e85a JH |
839 | static int |
840 | pdkim_body_complete(pdkim_ctx * ctx) | |
841 | { | |
842 | pdkim_signature * sig = ctx->sig; /*XXX assumes only one sig */ | |
843 | ||
844 | /* In simple body mode, if any empty lines were buffered, | |
845 | replace with one. rfc 4871 3.4.3 */ | |
846 | /*XXX checking the signed-body-bytes is a gross hack; I think | |
847 | it indicates that all linebreaks should be buffered, including | |
848 | the one terminating a text line */ | |
849 | ||
850 | if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE | |
851 | && sig->signed_body_bytes == 0 | |
852 | && ctx->num_buffered_crlf > 0 | |
853 | ) | |
854 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
855 | ||
856 | ctx->flags |= PDKIM_SEEN_EOD; | |
857 | ctx->linebuf_offset = 0; | |
858 | return PDKIM_OK; | |
859 | } | |
860 | ||
861 | ||
862 | ||
80a47a2c | 863 | /* -------------------------------------------------------------------------- */ |
e983e85a | 864 | /* Call from pdkim_feed below for processing complete body lines */ |
3045f050 | 865 | |
0d04a285 | 866 | static int |
3045f050 JH |
867 | pdkim_bodyline_complete(pdkim_ctx *ctx) |
868 | { | |
869 | char *p = ctx->linebuf; | |
870 | int n = ctx->linebuf_offset; | |
c14470c3 | 871 | pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */ |
3045f050 JH |
872 | |
873 | /* Ignore extra data if we've seen the end-of-data marker */ | |
e983e85a | 874 | if (ctx->flags & PDKIM_SEEN_EOD) goto BAIL; |
3045f050 JH |
875 | |
876 | /* We've always got one extra byte to stuff a zero ... */ | |
0d04a285 | 877 | ctx->linebuf[ctx->linebuf_offset] = '\0'; |
3045f050 | 878 | |
0d04a285 | 879 | /* Terminate on EOD marker */ |
e983e85a | 880 | if (ctx->flags & PDKIM_DOT_TERM) |
3045f050 | 881 | { |
e983e85a JH |
882 | if ( memcmp(p, ".\r\n", 3) == 0) |
883 | return pdkim_body_complete(ctx); | |
0d04a285 | 884 | |
e983e85a JH |
885 | /* Unstuff dots */ |
886 | if (memcmp(p, "..", 2) == 0) | |
887 | { | |
888 | p++; | |
889 | n--; | |
890 | } | |
80a47a2c TK |
891 | } |
892 | ||
3045f050 JH |
893 | /* Empty lines need to be buffered until we find a non-empty line */ |
894 | if (memcmp(p, "\r\n", 2) == 0) | |
895 | { | |
896 | ctx->num_buffered_crlf++; | |
897 | goto BAIL; | |
80a47a2c TK |
898 | } |
899 | ||
c14470c3 | 900 | if (sig && sig->canon_body == PDKIM_CANON_RELAXED) |
3045f050 JH |
901 | { |
902 | /* Lines with just spaces need to be buffered too */ | |
903 | char *check = p; | |
904 | while (memcmp(check, "\r\n", 2) != 0) | |
905 | { | |
906 | char c = *check; | |
6a11a9e6 | 907 | |
3045f050 JH |
908 | if (c != '\t' && c != ' ') |
909 | goto PROCESS; | |
910 | check++; | |
6a11a9e6 JH |
911 | } |
912 | ||
3045f050 JH |
913 | ctx->num_buffered_crlf++; |
914 | goto BAIL; | |
915 | } | |
6a11a9e6 | 916 | |
3045f050 JH |
917 | PROCESS: |
918 | /* At this point, we have a non-empty line, so release the buffered ones. */ | |
919 | while (ctx->num_buffered_crlf) | |
920 | { | |
921 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
922 | ctx->num_buffered_crlf--; | |
80a47a2c TK |
923 | } |
924 | ||
3045f050 | 925 | pdkim_update_bodyhash(ctx, p, n); |
80a47a2c | 926 | |
3045f050 JH |
927 | BAIL: |
928 | ctx->linebuf_offset = 0; | |
929 | return PDKIM_OK; | |
80a47a2c TK |
930 | } |
931 | ||
932 | ||
933 | /* -------------------------------------------------------------------------- */ | |
934 | /* Callback from pdkim_feed below for processing complete headers */ | |
935 | #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" | |
3045f050 | 936 | |
f444c2c7 | 937 | static int |
3045f050 JH |
938 | pdkim_header_complete(pdkim_ctx *ctx) |
939 | { | |
3045f050 | 940 | /* Special case: The last header can have an extra \r appended */ |
ca9cb170 JH |
941 | if ( (ctx->cur_header_len > 1) && |
942 | (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') ) | |
943 | --ctx->cur_header_len; | |
944 | ctx->cur_header[ctx->cur_header_len] = '\0'; | |
80a47a2c | 945 | |
3045f050 JH |
946 | ctx->num_headers++; |
947 | if (ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; | |
80a47a2c | 948 | |
3045f050 | 949 | /* SIGNING -------------------------------------------------------------- */ |
e983e85a | 950 | if (ctx->flags & PDKIM_MODE_SIGN) |
0d04a285 JH |
951 | { |
952 | pdkim_signature *sig; | |
953 | ||
954 | for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */ | |
80a47a2c | 955 | |
ab9152ff | 956 | /* Add header to the signed headers list (in reverse order) */ |
ca9cb170 JH |
957 | sig->headers = pdkim_prepend_stringlist(sig->headers, |
958 | ctx->cur_header); | |
0d04a285 | 959 | } |
94431adb | 960 | |
0d04a285 | 961 | /* VERIFICATION ----------------------------------------------------------- */ |
3045f050 | 962 | /* DKIM-Signature: headers are added to the verification list */ |
e983e85a | 963 | else |
3045f050 | 964 | { |
e2e3255a | 965 | if (strncasecmp(CCS ctx->cur_header, |
3045f050 | 966 | DKIM_SIGNATURE_HEADERNAME, |
e2e3255a | 967 | Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0) |
3045f050 JH |
968 | { |
969 | pdkim_signature *new_sig; | |
80a47a2c | 970 | |
3045f050 | 971 | /* Create and chain new signature block */ |
0d04a285 | 972 | DEBUG(D_acl) debug_printf( |
3045f050 | 973 | "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 | 974 | |
ca9cb170 | 975 | if ((new_sig = pdkim_parse_sig_header(ctx, ctx->cur_header))) |
3045f050 JH |
976 | { |
977 | pdkim_signature *last_sig = ctx->sig; | |
978 | if (!last_sig) | |
979 | ctx->sig = new_sig; | |
980 | else | |
981 | { | |
982 | while (last_sig->next) last_sig = last_sig->next; | |
983 | last_sig->next = new_sig; | |
984 | } | |
80a47a2c | 985 | } |
abe1010c | 986 | else |
0d04a285 JH |
987 | DEBUG(D_acl) debug_printf( |
988 | "Error while parsing signature header\n" | |
3045f050 | 989 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 990 | } |
37f8b554 | 991 | |
3045f050 JH |
992 | /* every other header is stored for signature verification */ |
993 | else | |
ca9cb170 | 994 | ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); |
80a47a2c TK |
995 | } |
996 | ||
3045f050 | 997 | BAIL: |
ca9cb170 JH |
998 | *ctx->cur_header = '\0'; |
999 | ctx->cur_header_len = 0; /* leave buffer for reuse */ | |
3045f050 | 1000 | return PDKIM_OK; |
6ab02e3f | 1001 | } |
80a47a2c TK |
1002 | |
1003 | ||
1004 | ||
1005 | /* -------------------------------------------------------------------------- */ | |
1006 | #define HEADER_BUFFER_FRAG_SIZE 256 | |
3045f050 JH |
1007 | |
1008 | DLLEXPORT int | |
ca9cb170 | 1009 | pdkim_feed(pdkim_ctx *ctx, char *data, int len) |
3045f050 JH |
1010 | { |
1011 | int p; | |
1012 | ||
e983e85a JH |
1013 | /* Alternate EOD signal, used in non-dotstuffing mode */ |
1014 | if (!data) | |
1015 | pdkim_body_complete(ctx); | |
1016 | ||
10c50704 | 1017 | else for (p = 0; p<len; p++) |
3045f050 | 1018 | { |
ca9cb170 | 1019 | uschar c = data[p]; |
3045f050 | 1020 | |
e983e85a | 1021 | if (ctx->flags & PDKIM_PAST_HDRS) |
3045f050 JH |
1022 | { |
1023 | /* Processing body byte */ | |
0d04a285 | 1024 | ctx->linebuf[ctx->linebuf_offset++] = c; |
3045f050 JH |
1025 | if (c == '\n') |
1026 | { | |
1027 | int rc = pdkim_bodyline_complete(ctx); /* End of line */ | |
1028 | if (rc != PDKIM_OK) return rc; | |
80a47a2c | 1029 | } |
3045f050 JH |
1030 | if (ctx->linebuf_offset == (PDKIM_MAX_BODY_LINE_LEN-1)) |
1031 | return PDKIM_ERR_LONG_LINE; | |
80a47a2c | 1032 | } |
3045f050 JH |
1033 | else |
1034 | { | |
1035 | /* Processing header byte */ | |
1036 | if (c != '\r') | |
1037 | { | |
1038 | if (c == '\n') | |
1039 | { | |
e983e85a | 1040 | if (ctx->flags & PDKIM_SEEN_LF) |
3045f050 JH |
1041 | { |
1042 | int rc = pdkim_header_complete(ctx); /* Seen last header line */ | |
1043 | if (rc != PDKIM_OK) return rc; | |
1044 | ||
e983e85a | 1045 | ctx->flags = ctx->flags & ~PDKIM_SEEN_LF | PDKIM_PAST_HDRS; |
0d04a285 | 1046 | DEBUG(D_acl) debug_printf( |
8ef02a06 | 1047 | "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 JH |
1048 | continue; |
1049 | } | |
1050 | else | |
e983e85a | 1051 | ctx->flags |= PDKIM_SEEN_LF; |
3045f050 | 1052 | } |
e983e85a | 1053 | else if (ctx->flags & PDKIM_SEEN_LF) |
3045f050 JH |
1054 | { |
1055 | if (!(c == '\t' || c == ' ')) | |
1056 | { | |
1057 | int rc = pdkim_header_complete(ctx); /* End of header */ | |
1058 | if (rc != PDKIM_OK) return rc; | |
1059 | } | |
e983e85a | 1060 | ctx->flags &= ~PDKIM_SEEN_LF; |
3045f050 | 1061 | } |
80a47a2c | 1062 | } |
3045f050 | 1063 | |
ca9cb170 | 1064 | if (ctx->cur_header_len < PDKIM_MAX_HEADER_LEN) |
c2f669a4 | 1065 | ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, |
e2e3255a | 1066 | &ctx->cur_header_len, CUS &data[p], 1); |
80a47a2c TK |
1067 | } |
1068 | } | |
3045f050 | 1069 | return PDKIM_OK; |
6ab02e3f | 1070 | } |
80a47a2c | 1071 | |
ca9cb170 JH |
1072 | |
1073 | ||
1074 | /* Extend a grwong header with a continuation-linebreak */ | |
1075 | static uschar * | |
1076 | pdkim_hdr_cont(uschar * str, int * size, int * ptr, int * col) | |
1077 | { | |
1078 | *col = 1; | |
c2f669a4 | 1079 | return string_catn(str, size, ptr, US"\r\n\t", 3); |
ca9cb170 JH |
1080 | } |
1081 | ||
1082 | ||
1083 | ||
05b7d6de JB |
1084 | /* |
1085 | * RFC 5322 specifies that header line length SHOULD be no more than 78 | |
1086 | * lets make it so! | |
1087 | * pdkim_headcat | |
ca9cb170 JH |
1088 | * |
1089 | * returns uschar * (not nul-terminated) | |
05b7d6de JB |
1090 | * |
1091 | * col: this int holds and receives column number (octets since last '\n') | |
1092 | * str: partial string to append to | |
ca9cb170 JH |
1093 | * size: current buffer size for str |
1094 | * ptr: current tail-pointer for str | |
94431adb | 1095 | * pad: padding, split line or space after before or after eg: ";" |
05b7d6de JB |
1096 | * intro: - must join to payload eg "h=", usually the tag name |
1097 | * payload: eg base64 data - long data can be split arbitrarily. | |
1098 | * | |
1099 | * this code doesn't fold the header in some of the places that RFC4871 | |
1100 | * allows: As per RFC5322(2.2.3) it only folds before or after tag-value | |
1101 | * pairs and inside long values. it also always spaces or breaks after the | |
94431adb | 1102 | * "pad" |
05b7d6de JB |
1103 | * |
1104 | * no guarantees are made for output given out-of range input. like tag | |
f444c2c7 | 1105 | * names longer than 78, or bogus col. Input is assumed to be free of line breaks. |
05b7d6de JB |
1106 | */ |
1107 | ||
ca9cb170 JH |
1108 | static uschar * |
1109 | pdkim_headcat(int * col, uschar * str, int * size, int * ptr, | |
1110 | const uschar * pad, const uschar * intro, const uschar * payload) | |
3045f050 JH |
1111 | { |
1112 | size_t l; | |
1113 | ||
1114 | if (pad) | |
05b7d6de | 1115 | { |
ca9cb170 | 1116 | l = Ustrlen(pad); |
3045f050 | 1117 | if (*col + l > 78) |
ca9cb170 | 1118 | str = pdkim_hdr_cont(str, size, ptr, col); |
c2f669a4 | 1119 | str = string_catn(str, size, ptr, pad, l); |
3045f050 | 1120 | *col += l; |
05b7d6de JB |
1121 | } |
1122 | ||
ca9cb170 | 1123 | l = (pad?1:0) + (intro?Ustrlen(intro):0); |
05b7d6de | 1124 | |
3045f050 | 1125 | if (*col + l > 78) |
05b7d6de | 1126 | { /*can't fit intro - start a new line to make room.*/ |
ca9cb170 JH |
1127 | str = pdkim_hdr_cont(str, size, ptr, col); |
1128 | l = intro?Ustrlen(intro):0; | |
05b7d6de JB |
1129 | } |
1130 | ||
ca9cb170 | 1131 | l += payload ? Ustrlen(payload):0 ; |
05b7d6de | 1132 | |
3045f050 | 1133 | while (l>77) |
05b7d6de | 1134 | { /* this fragment will not fit on a single line */ |
3045f050 | 1135 | if (pad) |
05b7d6de | 1136 | { |
c2f669a4 | 1137 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1138 | *col += 1; |
1139 | pad = NULL; /* only want this once */ | |
1140 | l--; | |
05b7d6de | 1141 | } |
3045f050 JH |
1142 | |
1143 | if (intro) | |
05b7d6de | 1144 | { |
ca9cb170 | 1145 | size_t sl = Ustrlen(intro); |
3045f050 | 1146 | |
c2f669a4 | 1147 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1148 | *col += sl; |
1149 | l -= sl; | |
1150 | intro = NULL; /* only want this once */ | |
05b7d6de | 1151 | } |
3045f050 JH |
1152 | |
1153 | if (payload) | |
05b7d6de | 1154 | { |
ca9cb170 | 1155 | size_t sl = Ustrlen(payload); |
3045f050 JH |
1156 | size_t chomp = *col+sl < 77 ? sl : 78-*col; |
1157 | ||
c2f669a4 | 1158 | str = string_catn(str, size, ptr, payload, chomp); |
3045f050 JH |
1159 | *col += chomp; |
1160 | payload += chomp; | |
1161 | l -= chomp-1; | |
05b7d6de | 1162 | } |
3045f050 JH |
1163 | |
1164 | /* the while precondition tells us it didn't fit. */ | |
ca9cb170 | 1165 | str = pdkim_hdr_cont(str, size, ptr, col); |
05b7d6de | 1166 | } |
3045f050 JH |
1167 | |
1168 | if (*col + l > 78) | |
05b7d6de | 1169 | { |
ca9cb170 | 1170 | str = pdkim_hdr_cont(str, size, ptr, col); |
3045f050 | 1171 | pad = NULL; |
05b7d6de JB |
1172 | } |
1173 | ||
3045f050 | 1174 | if (pad) |
05b7d6de | 1175 | { |
c2f669a4 | 1176 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1177 | *col += 1; |
1178 | pad = NULL; | |
05b7d6de JB |
1179 | } |
1180 | ||
3045f050 | 1181 | if (intro) |
05b7d6de | 1182 | { |
ca9cb170 | 1183 | size_t sl = Ustrlen(intro); |
3045f050 | 1184 | |
c2f669a4 | 1185 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1186 | *col += sl; |
1187 | l -= sl; | |
1188 | intro = NULL; | |
05b7d6de | 1189 | } |
3045f050 JH |
1190 | |
1191 | if (payload) | |
05b7d6de | 1192 | { |
ca9cb170 | 1193 | size_t sl = Ustrlen(payload); |
3045f050 | 1194 | |
c2f669a4 | 1195 | str = string_catn(str, size, ptr, payload, sl); |
3045f050 | 1196 | *col += sl; |
05b7d6de JB |
1197 | } |
1198 | ||
ca9cb170 | 1199 | return str; |
05b7d6de | 1200 | } |
80a47a2c | 1201 | |
3045f050 | 1202 | |
80a47a2c | 1203 | /* -------------------------------------------------------------------------- */ |
3045f050 | 1204 | |
ca9cb170 | 1205 | static uschar * |
2592e6c0 | 1206 | pdkim_create_header(pdkim_signature *sig, BOOL final) |
3045f050 | 1207 | { |
ca9cb170 JH |
1208 | uschar * base64_bh; |
1209 | uschar * base64_b; | |
3045f050 | 1210 | int col = 0; |
ca9cb170 JH |
1211 | uschar * hdr; int hdr_size = 0, hdr_len = 0; |
1212 | uschar * canon_all; int can_size = 0, can_len = 0; | |
3045f050 | 1213 | |
c2f669a4 JH |
1214 | canon_all = string_cat (NULL, &can_size, &can_len, |
1215 | pdkim_canons[sig->canon_headers]); | |
1216 | canon_all = string_catn(canon_all, &can_size, &can_len, US"/", 1); | |
1217 | canon_all = string_cat (canon_all, &can_size, &can_len, | |
1218 | pdkim_canons[sig->canon_body]); | |
ca9cb170 | 1219 | canon_all[can_len] = '\0'; |
3045f050 | 1220 | |
ca9cb170 | 1221 | hdr = string_cat(NULL, &hdr_size, &hdr_len, |
e2e3255a | 1222 | US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION); |
ca9cb170 | 1223 | col = hdr_len; |
3045f050 JH |
1224 | |
1225 | /* Required and static bits */ | |
ca9cb170 JH |
1226 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"a=", |
1227 | pdkim_algos[sig->algo]); | |
1228 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"q=", | |
1229 | pdkim_querymethods[sig->querymethod]); | |
1230 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"c=", | |
1231 | canon_all); | |
1232 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"d=", | |
1233 | sig->domain); | |
1234 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"s=", | |
1235 | sig->selector); | |
1236 | ||
1237 | /* list of header names can be split between items. */ | |
3045f050 | 1238 | { |
e2e3255a | 1239 | uschar * n = string_copy(sig->headernames); |
ca9cb170 JH |
1240 | uschar * i = US"h="; |
1241 | uschar * s = US";"; | |
1242 | ||
1243 | while (*n) | |
05b7d6de | 1244 | { |
ca9cb170 | 1245 | uschar * c = Ustrchr(n, ':'); |
3045f050 | 1246 | |
ca9cb170 | 1247 | if (c) *c ='\0'; |
05b7d6de | 1248 | |
ca9cb170 JH |
1249 | if (!i) |
1250 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, NULL, US":"); | |
05b7d6de | 1251 | |
ca9cb170 | 1252 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, s, i, n); |
3045f050 | 1253 | |
ca9cb170 JH |
1254 | if (!c) |
1255 | break; | |
3045f050 | 1256 | |
ca9cb170 JH |
1257 | n = c+1; |
1258 | s = NULL; | |
1259 | i = NULL; | |
80a47a2c | 1260 | } |
ca9cb170 | 1261 | } |
05b7d6de | 1262 | |
ca9cb170 JH |
1263 | base64_bh = pdkim_encode_base64(&sig->bodyhash); |
1264 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"bh=", base64_bh); | |
3045f050 | 1265 | |
ca9cb170 JH |
1266 | /* Optional bits */ |
1267 | if (sig->identity) | |
1268 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"i=", sig->identity); | |
3045f050 | 1269 | |
ca9cb170 JH |
1270 | if (sig->created > 0) |
1271 | { | |
e2e3255a | 1272 | uschar minibuf[20]; |
3045f050 | 1273 | |
e2e3255a | 1274 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created); |
ca9cb170 JH |
1275 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"t=", minibuf); |
1276 | } | |
3045f050 | 1277 | |
ca9cb170 JH |
1278 | if (sig->expires > 0) |
1279 | { | |
e2e3255a | 1280 | uschar minibuf[20]; |
3045f050 | 1281 | |
e2e3255a | 1282 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires); |
ca9cb170 JH |
1283 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"x=", minibuf); |
1284 | } | |
3045f050 | 1285 | |
ca9cb170 JH |
1286 | if (sig->bodylength >= 0) |
1287 | { | |
e2e3255a | 1288 | uschar minibuf[20]; |
80a47a2c | 1289 | |
e2e3255a | 1290 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength); |
ca9cb170 | 1291 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"l=", minibuf); |
3045f050 | 1292 | } |
05b7d6de | 1293 | |
ca9cb170 JH |
1294 | /* Preliminary or final version? */ |
1295 | base64_b = final ? pdkim_encode_base64(&sig->sigdata) : US""; | |
1296 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b); | |
80a47a2c | 1297 | |
ca9cb170 JH |
1298 | /* add trailing semicolon: I'm not sure if this is actually needed */ |
1299 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, US";", US""); | |
80a47a2c | 1300 | |
ca9cb170 JH |
1301 | hdr[hdr_len] = '\0'; |
1302 | return hdr; | |
80a47a2c TK |
1303 | } |
1304 | ||
1305 | ||
1306 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1307 | |
1308 | DLLEXPORT int | |
1309 | pdkim_feed_finish(pdkim_ctx *ctx, pdkim_signature **return_signatures) | |
1310 | { | |
1311 | pdkim_signature *sig = ctx->sig; | |
3045f050 JH |
1312 | |
1313 | /* Check if we must still flush a (partial) header. If that is the | |
1314 | case, the message has no body, and we must compute a body hash | |
1315 | out of '<CR><LF>' */ | |
ca9cb170 | 1316 | if (ctx->cur_header && ctx->cur_header_len) |
3045f050 JH |
1317 | { |
1318 | int rc = pdkim_header_complete(ctx); | |
1319 | if (rc != PDKIM_OK) return rc; | |
1320 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
80a47a2c | 1321 | } |
3045f050 | 1322 | else |
0d04a285 | 1323 | DEBUG(D_acl) debug_printf( |
3045f050 | 1324 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1325 | |
3045f050 | 1326 | /* Build (and/or evaluate) body hash */ |
ca9cb170 | 1327 | pdkim_finish_bodyhash(ctx); |
80a47a2c | 1328 | |
3045f050 JH |
1329 | while (sig) |
1330 | { | |
2592e6c0 JH |
1331 | BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1; |
1332 | hctx hhash_ctx; | |
ca9cb170 | 1333 | uschar * sig_hdr; |
2592e6c0 JH |
1334 | blob hhash; |
1335 | blob hdata; | |
cb224393 | 1336 | int hdata_alloc = 0; |
cb224393 | 1337 | |
2592e6c0 JH |
1338 | hdata.data = NULL; |
1339 | hdata.len = 0; | |
1340 | ||
1ed59855 | 1341 | exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256); |
80a47a2c | 1342 | |
0d04a285 JH |
1343 | DEBUG(D_acl) debug_printf( |
1344 | "PDKIM >> Hashed header data, canonicalized, in sequence >>>>>>>>>>>>>>\n"); | |
3045f050 JH |
1345 | |
1346 | /* SIGNING ---------------------------------------------------------------- */ | |
1347 | /* When signing, walk through our header list and add them to the hash. As we | |
8ef02a06 JH |
1348 | go, construct a list of the header's names to use for the h= parameter. |
1349 | Then append to that list any remaining header names for which there was no | |
1350 | header to sign. */ | |
3045f050 | 1351 | |
e983e85a | 1352 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1353 | { |
10c50704 JH |
1354 | uschar * headernames = NULL; /* Collected signed header names */ |
1355 | int hs = 0, hl = 0; | |
3045f050 | 1356 | pdkim_stringlist *p; |
8ef02a06 JH |
1357 | const uschar * l; |
1358 | uschar * s; | |
1359 | int sep = 0; | |
3045f050 JH |
1360 | |
1361 | for (p = sig->headers; p; p = p->next) | |
ab9152ff JH |
1362 | if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK) |
1363 | { | |
1364 | uschar * rh; | |
1365 | /* Collect header names (Note: colon presence is guaranteed here) */ | |
1366 | uschar * q = Ustrchr(p->value, ':'); | |
3045f050 | 1367 | |
c2f669a4 | 1368 | headernames = string_catn(headernames, &hs, &hl, |
ca9cb170 | 1369 | p->value, (q - US p->value) + (p->next ? 1 : 0)); |
3045f050 | 1370 | |
ab9152ff | 1371 | rh = sig->canon_headers == PDKIM_CANON_RELAXED |
ca9cb170 JH |
1372 | ? pdkim_relax_header(p->value, 1) /* cook header for relaxed canon */ |
1373 | : string_copy(CUS p->value); /* just copy it for simple canon */ | |
3045f050 | 1374 | |
ab9152ff | 1375 | /* Feed header to the hash algorithm */ |
e2e3255a | 1376 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); |
f444c2c7 | 1377 | |
ab9152ff JH |
1378 | /* Remember headers block for signing (when the library cannot do incremental) */ |
1379 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, rh); | |
3045f050 | 1380 | |
ab9152ff JH |
1381 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); |
1382 | } | |
8ef02a06 | 1383 | |
ca9cb170 | 1384 | l = sig->sign_headers; |
8ef02a06 JH |
1385 | while((s = string_nextinlist(&l, &sep, NULL, 0))) |
1386 | if (*s != '_') | |
ab9152ff | 1387 | { /*SSS string_append_listele() */ |
ca9cb170 | 1388 | if (hl > 0 && headernames[hl-1] != ':') |
c2f669a4 | 1389 | headernames = string_catn(headernames, &hs, &hl, US":", 1); |
ca9cb170 | 1390 | |
c2f669a4 | 1391 | headernames = string_cat(headernames, &hs, &hl, s); |
8ef02a06 | 1392 | } |
ca9cb170 JH |
1393 | headernames[hl] = '\0'; |
1394 | ||
1395 | /* Copy headernames to signature struct */ | |
1396 | sig->headernames = headernames; | |
ca9cb170 JH |
1397 | |
1398 | /* Create signature header with b= omitted */ | |
1399 | sig_hdr = pdkim_create_header(sig, FALSE); | |
80a47a2c | 1400 | } |
37f8b554 | 1401 | |
3045f050 JH |
1402 | /* VERIFICATION ----------------------------------------------------------- */ |
1403 | /* When verifying, walk through the header name list in the h= parameter and | |
1404 | add the headers to the hash in that order. */ | |
1405 | else | |
1406 | { | |
10c50704 | 1407 | uschar * p = sig->headernames; |
2592e6c0 JH |
1408 | uschar * q; |
1409 | pdkim_stringlist * hdrs; | |
3045f050 | 1410 | |
10c50704 | 1411 | if (p) |
3045f050 | 1412 | { |
10c50704 | 1413 | /* clear tags */ |
3045f050 | 1414 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) |
10c50704 | 1415 | hdrs->tag = 0; |
3045f050 | 1416 | |
10c50704 JH |
1417 | p = string_copy(p); |
1418 | while(1) | |
1419 | { | |
1420 | if ((q = Ustrchr(p, ':'))) | |
1421 | *q = '\0'; | |
1422 | ||
1423 | /*XXX walk the list of headers in same order as received. */ | |
1424 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) | |
1425 | if ( hdrs->tag == 0 | |
1426 | && strncasecmp(hdrs->value, CS p, Ustrlen(p)) == 0 | |
1427 | && (hdrs->value)[Ustrlen(p)] == ':' | |
1428 | ) | |
1429 | { | |
1430 | /* cook header for relaxed canon, or just copy it for simple */ | |
1431 | ||
1432 | uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED | |
1433 | ? pdkim_relax_header(hdrs->value, 1) | |
1434 | : string_copy(CUS hdrs->value); | |
1435 | ||
1436 | /* Feed header to the hash algorithm */ | |
1437 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); | |
1438 | ||
1439 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); | |
1440 | hdrs->tag = 1; | |
1441 | break; | |
1442 | } | |
3045f050 | 1443 | |
10c50704 JH |
1444 | if (!q) break; |
1445 | p = q+1; | |
1446 | } | |
3045f050 | 1447 | |
10c50704 | 1448 | sig_hdr = string_copy(sig->rawsig_no_b_val); |
80a47a2c | 1449 | } |
80a47a2c TK |
1450 | } |
1451 | ||
0d04a285 | 1452 | DEBUG(D_acl) debug_printf( |
3045f050 | 1453 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1454 | |
3045f050 JH |
1455 | /* Relax header if necessary */ |
1456 | if (sig->canon_headers == PDKIM_CANON_RELAXED) | |
ca9cb170 | 1457 | sig_hdr = pdkim_relax_header(sig_hdr, 0); |
80a47a2c | 1458 | |
0d04a285 | 1459 | DEBUG(D_acl) |
3045f050 | 1460 | { |
0d04a285 | 1461 | debug_printf( |
3045f050 | 1462 | "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 1463 | pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr)); |
0d04a285 | 1464 | debug_printf( |
3045f050 | 1465 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1466 | } |
3045f050 JH |
1467 | |
1468 | /* Finalize header hash */ | |
e2e3255a | 1469 | exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr)); |
2592e6c0 | 1470 | exim_sha_finish(&hhash_ctx, &hhash); |
3045f050 | 1471 | |
f444c2c7 JH |
1472 | DEBUG(D_acl) |
1473 | { | |
1474 | debug_printf("PDKIM [%s] hh computed: ", sig->domain); | |
2592e6c0 | 1475 | pdkim_hexprint(hhash.data, hhash.len); |
80a47a2c TK |
1476 | } |
1477 | ||
2592e6c0 | 1478 | /* Remember headers block for signing (when the library cannot do incremental) */ |
e983e85a | 1479 | if (ctx->flags & PDKIM_MODE_SIGN) |
b78006ac | 1480 | (void) exim_rsa_data_append(&hdata, &hdata_alloc, US sig_hdr); |
f444c2c7 | 1481 | |
3045f050 | 1482 | /* SIGNING ---------------------------------------------------------------- */ |
e983e85a | 1483 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1484 | { |
2592e6c0 JH |
1485 | es_ctx sctx; |
1486 | const uschar * errstr; | |
f444c2c7 JH |
1487 | |
1488 | /* Import private key */ | |
b78006ac | 1489 | if ((errstr = exim_rsa_signing_init(US sig->rsa_privkey, &sctx))) |
f444c2c7 | 1490 | { |
2592e6c0 | 1491 | DEBUG(D_acl) debug_printf("signing_init: %s\n", errstr); |
f444c2c7 JH |
1492 | return PDKIM_ERR_RSA_PRIVKEY; |
1493 | } | |
80a47a2c | 1494 | |
2592e6c0 JH |
1495 | /* Do signing. With OpenSSL we are signing the hash of headers just |
1496 | calculated, with GnuTLS we have to sign an entire block of headers | |
1497 | (due to available interfaces) and it recalculates the hash internally. */ | |
f444c2c7 | 1498 | |
2592e6c0 JH |
1499 | #if defined(RSA_OPENSSL) || defined(RSA_GCRYPT) |
1500 | hdata = hhash; | |
f444c2c7 JH |
1501 | #endif |
1502 | ||
2592e6c0 | 1503 | if ((errstr = exim_rsa_sign(&sctx, is_sha1, &hdata, &sig->sigdata))) |
f444c2c7 | 1504 | { |
2592e6c0 | 1505 | DEBUG(D_acl) debug_printf("signing: %s\n", errstr); |
f444c2c7 JH |
1506 | return PDKIM_ERR_RSA_SIGNING; |
1507 | } | |
80a47a2c | 1508 | |
0d04a285 | 1509 | DEBUG(D_acl) |
3045f050 | 1510 | { |
0d04a285 | 1511 | debug_printf( "PDKIM [%s] b computed: ", sig->domain); |
2592e6c0 | 1512 | pdkim_hexprint(sig->sigdata.data, sig->sigdata.len); |
80a47a2c | 1513 | } |
80a47a2c | 1514 | |
ca9cb170 | 1515 | sig->signature_header = pdkim_create_header(sig, TRUE); |
80a47a2c | 1516 | } |
80a47a2c | 1517 | |
3045f050 JH |
1518 | /* VERIFICATION ----------------------------------------------------------- */ |
1519 | else | |
1520 | { | |
2592e6c0 JH |
1521 | ev_ctx vctx; |
1522 | const uschar * errstr; | |
3045f050 | 1523 | |
ca9cb170 | 1524 | uschar *dns_txt_name, *dns_txt_reply; |
f444c2c7 | 1525 | |
07eeb4df | 1526 | /* Make sure we have all required signature tags */ |
1527 | if (!( sig->domain && *sig->domain | |
1528 | && sig->selector && *sig->selector | |
1529 | && sig->headernames && *sig->headernames | |
1530 | && sig->bodyhash.data | |
1531 | && sig->sigdata.data | |
1532 | && sig->algo > -1 | |
1533 | && sig->version | |
1534 | ) ) | |
1535 | { | |
1536 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1537 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR; | |
1538 | ||
1539 | DEBUG(D_acl) debug_printf( | |
1540 | " Error in DKIM-Signature header: tags missing or invalid\n" | |
1541 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1542 | goto NEXT_VERIFY; | |
1543 | } | |
1544 | ||
1545 | /* Make sure sig uses supported DKIM version (only v1) */ | |
1546 | if (sig->version != 1) | |
1547 | { | |
1548 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1549 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION; | |
1550 | ||
1551 | DEBUG(D_acl) debug_printf( | |
1552 | " Error in DKIM-Signature header: unsupported DKIM version\n" | |
1553 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1554 | goto NEXT_VERIFY; | |
1555 | } | |
1556 | ||
f444c2c7 | 1557 | /* Fetch public key for signing domain, from DNS */ |
3045f050 | 1558 | |
ca9cb170 JH |
1559 | dns_txt_name = string_sprintf("%s._domainkey.%s.", |
1560 | sig->selector, sig->domain); | |
80a47a2c | 1561 | |
ca9cb170 | 1562 | dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1563 | memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN); |
3045f050 | 1564 | |
ca9cb170 | 1565 | if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK |
3045f050 JH |
1566 | || dns_txt_reply[0] == '\0') |
1567 | { | |
1568 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1569 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE; | |
1570 | goto NEXT_VERIFY; | |
80a47a2c TK |
1571 | } |
1572 | ||
0d04a285 | 1573 | DEBUG(D_acl) |
3045f050 | 1574 | { |
0d04a285 | 1575 | debug_printf( |
2592e6c0 JH |
1576 | "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" |
1577 | " Raw record: "); | |
ca9cb170 | 1578 | pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply)); |
80a47a2c | 1579 | } |
3045f050 | 1580 | |
e2e3255a | 1581 | if (!(sig->pubkey = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply))) |
3045f050 JH |
1582 | { |
1583 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
df3def24 | 1584 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD; |
3045f050 | 1585 | |
0d04a285 JH |
1586 | DEBUG(D_acl) debug_printf( |
1587 | " Error while parsing public key record\n" | |
3045f050 | 1588 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
3045f050 | 1589 | goto NEXT_VERIFY; |
80a47a2c TK |
1590 | } |
1591 | ||
0d04a285 | 1592 | DEBUG(D_acl) debug_printf( |
2592e6c0 | 1593 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
3045f050 | 1594 | |
f444c2c7 | 1595 | /* Import public key */ |
2592e6c0 | 1596 | if ((errstr = exim_rsa_verify_init(&sig->pubkey->key, &vctx))) |
3045f050 | 1597 | { |
2592e6c0 | 1598 | DEBUG(D_acl) debug_printf("verify_init: %s\n", errstr); |
3045f050 | 1599 | sig->verify_status = PDKIM_VERIFY_INVALID; |
df3def24 | 1600 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; |
3045f050 | 1601 | goto NEXT_VERIFY; |
80a47a2c TK |
1602 | } |
1603 | ||
3045f050 | 1604 | /* Check the signature */ |
2592e6c0 | 1605 | if ((errstr = exim_rsa_verify(&vctx, is_sha1, &hhash, &sig->sigdata))) |
3045f050 | 1606 | { |
2592e6c0 | 1607 | DEBUG(D_acl) debug_printf("headers verify: %s\n", errstr); |
3045f050 JH |
1608 | sig->verify_status = PDKIM_VERIFY_FAIL; |
1609 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; | |
1610 | goto NEXT_VERIFY; | |
ff7ddfd7 TK |
1611 | } |
1612 | ||
2592e6c0 | 1613 | |
3045f050 JH |
1614 | /* We have a winner! (if bodydhash was correct earlier) */ |
1615 | if (sig->verify_status == PDKIM_VERIFY_NONE) | |
1616 | sig->verify_status = PDKIM_VERIFY_PASS; | |
1617 | ||
1618 | NEXT_VERIFY: | |
1619 | ||
0d04a285 | 1620 | DEBUG(D_acl) |
3045f050 | 1621 | { |
0d04a285 | 1622 | debug_printf("PDKIM [%s] signature status: %s", |
3045f050 JH |
1623 | sig->domain, pdkim_verify_status_str(sig->verify_status)); |
1624 | if (sig->verify_ext_status > 0) | |
0d04a285 | 1625 | debug_printf(" (%s)\n", |
3045f050 JH |
1626 | pdkim_verify_ext_status_str(sig->verify_ext_status)); |
1627 | else | |
0d04a285 | 1628 | debug_printf("\n"); |
80a47a2c | 1629 | } |
80a47a2c TK |
1630 | } |
1631 | ||
3045f050 | 1632 | sig = sig->next; |
80a47a2c TK |
1633 | } |
1634 | ||
3045f050 JH |
1635 | /* If requested, set return pointer to signature(s) */ |
1636 | if (return_signatures) | |
1637 | *return_signatures = ctx->sig; | |
80a47a2c | 1638 | |
3045f050 | 1639 | return PDKIM_OK; |
80a47a2c TK |
1640 | } |
1641 | ||
1642 | ||
1643 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1644 | |
1645 | DLLEXPORT pdkim_ctx * | |
e983e85a | 1646 | pdkim_init_verify(int(*dns_txt_callback)(char *, char *), BOOL dot_stuffing) |
3045f050 | 1647 | { |
ca9cb170 | 1648 | pdkim_ctx * ctx; |
3045f050 | 1649 | |
ca9cb170 | 1650 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1651 | memset(ctx, 0, sizeof(pdkim_ctx)); |
3045f050 | 1652 | |
e983e85a | 1653 | if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM; |
ca9cb170 | 1654 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
3045f050 | 1655 | ctx->dns_txt_callback = dns_txt_callback; |
80a47a2c | 1656 | |
3045f050 | 1657 | return ctx; |
80a47a2c TK |
1658 | } |
1659 | ||
1660 | ||
1661 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 1662 | |
3045f050 | 1663 | DLLEXPORT pdkim_ctx * |
e983e85a JH |
1664 | pdkim_init_sign(char *domain, char *selector, char *rsa_privkey, int algo, |
1665 | BOOL dot_stuffed) | |
3045f050 JH |
1666 | { |
1667 | pdkim_ctx *ctx; | |
1668 | pdkim_signature *sig; | |
80a47a2c | 1669 | |
3045f050 JH |
1670 | if (!domain || !selector || !rsa_privkey) |
1671 | return NULL; | |
80a47a2c | 1672 | |
ca9cb170 | 1673 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1674 | memset(ctx, 0, sizeof(pdkim_ctx)); |
80a47a2c | 1675 | |
e983e85a | 1676 | ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN; |
ca9cb170 | 1677 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
80a47a2c | 1678 | |
ca9cb170 | 1679 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 1680 | memset(sig, 0, sizeof(pdkim_signature)); |
80a47a2c | 1681 | |
3045f050 | 1682 | sig->bodylength = -1; |
3045f050 | 1683 | ctx->sig = sig; |
80a47a2c | 1684 | |
e2e3255a JH |
1685 | sig->domain = string_copy(US domain); |
1686 | sig->selector = string_copy(US selector); | |
1687 | sig->rsa_privkey = string_copy(US rsa_privkey); | |
2592e6c0 | 1688 | sig->algo = algo; |
cb224393 | 1689 | |
1ed59855 | 1690 | exim_sha_init(&sig->body_hash, algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256); |
3045f050 | 1691 | return ctx; |
6ab02e3f | 1692 | } |
80a47a2c | 1693 | |
f444c2c7 | 1694 | |
80a47a2c | 1695 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
1696 | |
1697 | DLLEXPORT int | |
1698 | pdkim_set_optional(pdkim_ctx *ctx, | |
80a47a2c TK |
1699 | char *sign_headers, |
1700 | char *identity, | |
1701 | int canon_headers, | |
1702 | int canon_body, | |
1703 | long bodylength, | |
80a47a2c | 1704 | unsigned long created, |
3045f050 JH |
1705 | unsigned long expires) |
1706 | { | |
8ef02a06 JH |
1707 | pdkim_signature * sig = ctx->sig; |
1708 | ||
3045f050 | 1709 | if (identity) |
e2e3255a | 1710 | sig->identity = string_copy(US identity); |
80a47a2c | 1711 | |
ca9cb170 JH |
1712 | sig->sign_headers = string_copy(sign_headers |
1713 | ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS); | |
80a47a2c | 1714 | |
8ef02a06 JH |
1715 | sig->canon_headers = canon_headers; |
1716 | sig->canon_body = canon_body; | |
1717 | sig->bodylength = bodylength; | |
1718 | sig->created = created; | |
1719 | sig->expires = expires; | |
80a47a2c | 1720 | |
3045f050 | 1721 | return PDKIM_OK; |
6ab02e3f | 1722 | } |
3045f050 | 1723 | |
3045f050 | 1724 | |
2592e6c0 JH |
1725 | void |
1726 | pdkim_init(void) | |
1727 | { | |
1728 | exim_rsa_init(); | |
1729 | } | |
1730 | ||
1731 | ||
1732 | ||
f444c2c7 | 1733 | #endif /*DISABLE_DKIM*/ |