Commit | Line | Data |
---|---|---|
80a47a2c TK |
1 | /* |
2 | * PDKIM - a RFC4871 (DKIM) implementation | |
3 | * | |
f444c2c7 | 4 | * Copyright (C) 2009 - 2016 Tom Kistner <tom@duncanthrax.net> |
d4e5e70b | 5 | * Copyright (C) 2016 - 2017 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" | |
9b2583c4 | 45 | #include "signing.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 | }; | |
9b2583c4 | 86 | /*XXX currently unused */ |
e2e3255a JH |
87 | const uschar * pdkim_hashes[] = { |
88 | US"sha256", | |
89 | US"sha1", | |
80a47a2c TK |
90 | NULL |
91 | }; | |
9b2583c4 | 92 | /*XXX currently unused */ |
e2e3255a JH |
93 | const uschar * pdkim_keytypes[] = { |
94 | US"rsa", | |
80a47a2c TK |
95 | NULL |
96 | }; | |
97 | ||
98 | typedef struct pdkim_combined_canon_entry { | |
e2e3255a | 99 | const uschar * str; |
80a47a2c TK |
100 | int canon_headers; |
101 | int canon_body; | |
102 | } pdkim_combined_canon_entry; | |
f444c2c7 | 103 | |
80a47a2c | 104 | pdkim_combined_canon_entry pdkim_combined_canons[] = { |
e2e3255a JH |
105 | { US"simple/simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, |
106 | { US"simple/relaxed", PDKIM_CANON_SIMPLE, PDKIM_CANON_RELAXED }, | |
107 | { US"relaxed/simple", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, | |
108 | { US"relaxed/relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_RELAXED }, | |
109 | { US"simple", PDKIM_CANON_SIMPLE, PDKIM_CANON_SIMPLE }, | |
110 | { US"relaxed", PDKIM_CANON_RELAXED, PDKIM_CANON_SIMPLE }, | |
111 | { NULL, 0, 0 } | |
80a47a2c TK |
112 | }; |
113 | ||
114 | ||
f444c2c7 JH |
115 | /* -------------------------------------------------------------------------- */ |
116 | ||
117 | const char * | |
118 | pdkim_verify_status_str(int status) | |
119 | { | |
f7302073 JH |
120 | switch(status) |
121 | { | |
122 | case PDKIM_VERIFY_NONE: return "PDKIM_VERIFY_NONE"; | |
123 | case PDKIM_VERIFY_INVALID: return "PDKIM_VERIFY_INVALID"; | |
124 | case PDKIM_VERIFY_FAIL: return "PDKIM_VERIFY_FAIL"; | |
125 | case PDKIM_VERIFY_PASS: return "PDKIM_VERIFY_PASS"; | |
126 | default: return "PDKIM_VERIFY_UNKNOWN"; | |
ff7ddfd7 TK |
127 | } |
128 | } | |
f444c2c7 JH |
129 | |
130 | const char * | |
131 | pdkim_verify_ext_status_str(int ext_status) | |
132 | { | |
f7302073 JH |
133 | switch(ext_status) |
134 | { | |
135 | case PDKIM_VERIFY_FAIL_BODY: return "PDKIM_VERIFY_FAIL_BODY"; | |
136 | case PDKIM_VERIFY_FAIL_MESSAGE: return "PDKIM_VERIFY_FAIL_MESSAGE"; | |
135e9496 | 137 | case PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH: return "PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH"; |
f7302073 JH |
138 | case PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE: return "PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE"; |
139 | case PDKIM_VERIFY_INVALID_BUFFER_SIZE: return "PDKIM_VERIFY_INVALID_BUFFER_SIZE"; | |
140 | case PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD: return "PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD"; | |
141 | case PDKIM_VERIFY_INVALID_PUBKEY_IMPORT: return "PDKIM_VERIFY_INVALID_PUBKEY_IMPORT"; | |
142 | case PDKIM_VERIFY_INVALID_SIGNATURE_ERROR: return "PDKIM_VERIFY_INVALID_SIGNATURE_ERROR"; | |
143 | case PDKIM_VERIFY_INVALID_DKIM_VERSION: return "PDKIM_VERIFY_INVALID_DKIM_VERSION"; | |
144 | default: return "PDKIM_VERIFY_UNKNOWN"; | |
145 | } | |
146 | } | |
147 | ||
b9df1829 | 148 | const uschar * |
f7302073 JH |
149 | pdkim_errstr(int status) |
150 | { | |
151 | switch(status) | |
152 | { | |
b9df1829 JH |
153 | case PDKIM_OK: return US"OK"; |
154 | case PDKIM_FAIL: return US"FAIL"; | |
155 | case PDKIM_ERR_RSA_PRIVKEY: return US"RSA_PRIVKEY"; | |
156 | case PDKIM_ERR_RSA_SIGNING: return US"RSA SIGNING"; | |
157 | case PDKIM_ERR_LONG_LINE: return US"RSA_LONG_LINE"; | |
158 | case PDKIM_ERR_BUFFER_TOO_SMALL: return US"BUFFER_TOO_SMALL"; | |
159 | case PDKIM_SIGN_PRIVKEY_WRAP: return US"PRIVKEY_WRAP"; | |
160 | case PDKIM_SIGN_PRIVKEY_B64D: return US"PRIVKEY_B64D"; | |
ef698bf6 | 161 | default: return US"(unknown)"; |
ff7ddfd7 TK |
162 | } |
163 | } | |
164 | ||
165 | ||
80a47a2c TK |
166 | /* -------------------------------------------------------------------------- */ |
167 | /* Print debugging functions */ | |
2592e6c0 | 168 | static void |
b78006ac | 169 | pdkim_quoteprint(const uschar *data, int len) |
3045f050 JH |
170 | { |
171 | int i; | |
0d04a285 | 172 | for (i = 0; i < len; i++) |
3045f050 | 173 | { |
b78006ac | 174 | const int c = data[i]; |
3045f050 JH |
175 | switch (c) |
176 | { | |
0d04a285 JH |
177 | case ' ' : debug_printf("{SP}"); break; |
178 | case '\t': debug_printf("{TB}"); break; | |
179 | case '\r': debug_printf("{CR}"); break; | |
180 | case '\n': debug_printf("{LF}"); break; | |
181 | case '{' : debug_printf("{BO}"); break; | |
182 | case '}' : debug_printf("{BC}"); break; | |
3045f050 JH |
183 | default: |
184 | if ( (c < 32) || (c > 127) ) | |
0d04a285 | 185 | debug_printf("{%02x}", c); |
3045f050 | 186 | else |
0d04a285 | 187 | debug_printf("%c", c); |
80a47a2c TK |
188 | break; |
189 | } | |
190 | } | |
2592e6c0 | 191 | debug_printf("\n"); |
80a47a2c | 192 | } |
80a47a2c | 193 | |
2592e6c0 | 194 | static void |
b78006ac | 195 | pdkim_hexprint(const uschar *data, int len) |
3045f050 JH |
196 | { |
197 | int i; | |
02c4f8fb JH |
198 | if (data) for (i = 0 ; i < len; i++) debug_printf("%02x", data[i]); |
199 | else debug_printf("<NULL>"); | |
2592e6c0 | 200 | debug_printf("\n"); |
80a47a2c | 201 | } |
80a47a2c TK |
202 | |
203 | ||
f444c2c7 | 204 | |
f444c2c7 | 205 | static pdkim_stringlist * |
ca9cb170 | 206 | pdkim_prepend_stringlist(pdkim_stringlist * base, const uschar * str) |
3045f050 | 207 | { |
ca9cb170 | 208 | pdkim_stringlist * new_entry = store_get(sizeof(pdkim_stringlist)); |
3045f050 | 209 | |
abe1010c | 210 | memset(new_entry, 0, sizeof(pdkim_stringlist)); |
ca9cb170 | 211 | new_entry->value = string_copy(str); |
ab9152ff JH |
212 | if (base) new_entry->next = base; |
213 | return new_entry; | |
6ab02e3f | 214 | } |
80a47a2c TK |
215 | |
216 | ||
8ef02a06 JH |
217 | |
218 | /* Trim whitespace fore & aft */ | |
219 | ||
ca9cb170 JH |
220 | static void |
221 | pdkim_strtrim(uschar * str) | |
3045f050 | 222 | { |
ca9cb170 JH |
223 | uschar * p = str; |
224 | uschar * q = str; | |
8ef02a06 JH |
225 | while (*p == '\t' || *p == ' ') p++; /* skip whitespace */ |
226 | while (*p) {*q = *p; q++; p++;} /* dump the leading whitespace */ | |
3045f050 | 227 | *q = '\0'; |
ca9cb170 | 228 | while (q != str && ( (*q == '\0') || (*q == '\t') || (*q == ' ') ) ) |
8ef02a06 | 229 | { /* dump trailing whitespace */ |
80a47a2c | 230 | *q = '\0'; |
3045f050 | 231 | q--; |
80a47a2c | 232 | } |
8ef02a06 JH |
233 | } |
234 | ||
235 | ||
80a47a2c | 236 | |
80a47a2c | 237 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
238 | |
239 | DLLEXPORT void | |
240 | pdkim_free_ctx(pdkim_ctx *ctx) | |
241 | { | |
6ab02e3f | 242 | } |
80a47a2c TK |
243 | |
244 | ||
245 | /* -------------------------------------------------------------------------- */ | |
246 | /* Matches the name of the passed raw "header" against | |
8ef02a06 JH |
247 | the passed colon-separated "tick", and invalidates |
248 | the entry in tick. Returns OK or fail-code */ | |
249 | /*XXX might be safer done using a pdkim_stringlist for "tick" */ | |
3045f050 | 250 | |
f444c2c7 | 251 | static int |
e2e3255a | 252 | header_name_match(const uschar * header, uschar * tick) |
3045f050 | 253 | { |
ca9cb170 JH |
254 | uschar * hname; |
255 | uschar * lcopy; | |
256 | uschar * p; | |
257 | uschar * q; | |
258 | uschar * hcolon = Ustrchr(header, ':'); /* Get header name */ | |
3045f050 | 259 | |
ca9cb170 JH |
260 | if (!hcolon) |
261 | return PDKIM_FAIL; /* This isn't a header */ | |
3045f050 | 262 | |
ca9cb170 JH |
263 | /* if we had strncmpic() we wouldn't need this copy */ |
264 | hname = string_copyn(header, hcolon-header); | |
3045f050 JH |
265 | |
266 | /* Copy tick-off list locally, so we can punch zeroes into it */ | |
ca9cb170 JH |
267 | p = lcopy = string_copy(tick); |
268 | ||
269 | for (q = Ustrchr(p, ':'); q; q = Ustrchr(p, ':')) | |
3045f050 JH |
270 | { |
271 | *q = '\0'; | |
ca9cb170 JH |
272 | if (strcmpic(p, hname) == 0) |
273 | goto found; | |
80a47a2c | 274 | |
3045f050 | 275 | p = q+1; |
80a47a2c TK |
276 | } |
277 | ||
ca9cb170 JH |
278 | if (strcmpic(p, hname) == 0) |
279 | goto found; | |
280 | ||
281 | return PDKIM_FAIL; | |
282 | ||
283 | found: | |
3045f050 | 284 | /* Invalidate header name instance in tick-off list */ |
8ef02a06 | 285 | tick[p-lcopy] = '_'; |
ca9cb170 | 286 | return PDKIM_OK; |
80a47a2c TK |
287 | } |
288 | ||
289 | ||
290 | /* -------------------------------------------------------------------------- */ | |
ca9cb170 | 291 | /* Performs "relaxed" canonicalization of a header. */ |
3045f050 | 292 | |
ca9cb170 | 293 | static uschar * |
ea18931d | 294 | pdkim_relax_header(const uschar * header, BOOL append_crlf) |
3045f050 JH |
295 | { |
296 | BOOL past_field_name = FALSE; | |
297 | BOOL seen_wsp = FALSE; | |
ca9cb170 JH |
298 | const uschar * p; |
299 | uschar * relaxed = store_get(Ustrlen(header)+3); | |
300 | uschar * q = relaxed; | |
3045f050 | 301 | |
ca9cb170 | 302 | for (p = header; *p; p++) |
3045f050 | 303 | { |
ca9cb170 | 304 | uschar c = *p; |
ea18931d JH |
305 | |
306 | if (c == '\r' || c == '\n') /* Ignore CR & LF */ | |
3045f050 JH |
307 | continue; |
308 | if (c == '\t' || c == ' ') | |
309 | { | |
310 | if (seen_wsp) | |
80a47a2c | 311 | continue; |
3045f050 JH |
312 | c = ' '; /* Turns WSP into SP */ |
313 | seen_wsp = TRUE; | |
80a47a2c | 314 | } |
3045f050 JH |
315 | else |
316 | if (!past_field_name && c == ':') | |
317 | { | |
ea18931d JH |
318 | if (seen_wsp) q--; /* This removes WSP immediately before the colon */ |
319 | seen_wsp = TRUE; /* This removes WSP immediately after the colon */ | |
3045f050 | 320 | past_field_name = TRUE; |
80a47a2c | 321 | } |
3045f050 JH |
322 | else |
323 | seen_wsp = FALSE; | |
324 | ||
325 | /* Lowercase header name */ | |
326 | if (!past_field_name) c = tolower(c); | |
327 | *q++ = c; | |
80a47a2c | 328 | } |
3045f050 JH |
329 | |
330 | if (q > relaxed && q[-1] == ' ') q--; /* Squash eventual trailing SP */ | |
3045f050 | 331 | |
ea18931d | 332 | if (append_crlf) { *q++ = '\r'; *q++ = '\n'; } |
ca9cb170 | 333 | *q = '\0'; |
3045f050 | 334 | return relaxed; |
6ab02e3f | 335 | } |
80a47a2c TK |
336 | |
337 | ||
338 | /* -------------------------------------------------------------------------- */ | |
339 | #define PDKIM_QP_ERROR_DECODE -1 | |
3045f050 | 340 | |
35cf75e9 JH |
341 | static const uschar * |
342 | pdkim_decode_qp_char(const uschar *qp_p, int *c) | |
3045f050 | 343 | { |
35cf75e9 | 344 | const uschar *initial_pos = qp_p; |
3045f050 JH |
345 | |
346 | /* Advance one char */ | |
347 | qp_p++; | |
348 | ||
349 | /* Check for two hex digits and decode them */ | |
350 | if (isxdigit(*qp_p) && isxdigit(qp_p[1])) | |
351 | { | |
352 | /* Do hex conversion */ | |
353 | *c = (isdigit(*qp_p) ? *qp_p - '0' : toupper(*qp_p) - 'A' + 10) << 4; | |
a5840e10 | 354 | *c |= isdigit(qp_p[1]) ? qp_p[1] - '0' : toupper(qp_p[1]) - 'A' + 10; |
3045f050 | 355 | return qp_p + 2; |
6ab02e3f | 356 | } |
80a47a2c | 357 | |
3045f050 JH |
358 | /* Illegal char here */ |
359 | *c = PDKIM_QP_ERROR_DECODE; | |
360 | return initial_pos; | |
80a47a2c TK |
361 | } |
362 | ||
363 | ||
364 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 365 | |
e2e3255a | 366 | static uschar * |
35cf75e9 | 367 | pdkim_decode_qp(const uschar * str) |
3045f050 JH |
368 | { |
369 | int nchar = 0; | |
ca9cb170 | 370 | uschar * q; |
35cf75e9 | 371 | const uschar * p = str; |
ca9cb170 | 372 | uschar * n = store_get(Ustrlen(str)+1); |
3045f050 JH |
373 | |
374 | *n = '\0'; | |
375 | q = n; | |
ca9cb170 | 376 | while (*p) |
3045f050 JH |
377 | { |
378 | if (*p == '=') | |
379 | { | |
380 | p = pdkim_decode_qp_char(p, &nchar); | |
381 | if (nchar >= 0) | |
382 | { | |
383 | *q++ = nchar; | |
384 | continue; | |
80a47a2c TK |
385 | } |
386 | } | |
3045f050 JH |
387 | else |
388 | *q++ = *p; | |
389 | p++; | |
80a47a2c | 390 | } |
3045f050 JH |
391 | *q = '\0'; |
392 | return n; | |
80a47a2c TK |
393 | } |
394 | ||
395 | ||
396 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 397 | |
2592e6c0 | 398 | static void |
35cf75e9 | 399 | pdkim_decode_base64(const uschar * str, blob * b) |
3045f050 | 400 | { |
2592e6c0 | 401 | int dlen; |
2592e6c0 JH |
402 | dlen = b64decode(str, &b->data); |
403 | if (dlen < 0) b->data = NULL; | |
404 | b->len = dlen; | |
80a47a2c TK |
405 | } |
406 | ||
ca9cb170 | 407 | static uschar * |
2592e6c0 | 408 | pdkim_encode_base64(blob * b) |
3045f050 | 409 | { |
ca9cb170 | 410 | return b64encode(b->data, b->len); |
80a47a2c TK |
411 | } |
412 | ||
413 | ||
414 | /* -------------------------------------------------------------------------- */ | |
415 | #define PDKIM_HDR_LIMBO 0 | |
416 | #define PDKIM_HDR_TAG 1 | |
417 | #define PDKIM_HDR_VALUE 2 | |
3045f050 | 418 | |
f444c2c7 | 419 | static pdkim_signature * |
ca9cb170 | 420 | pdkim_parse_sig_header(pdkim_ctx *ctx, uschar * raw_hdr) |
3045f050 | 421 | { |
2c0f3ea1 | 422 | pdkim_signature * sig; |
ca9cb170 JH |
423 | uschar *p, *q; |
424 | uschar * cur_tag = NULL; int ts = 0, tl = 0; | |
425 | uschar * cur_val = NULL; int vs = 0, vl = 0; | |
3045f050 JH |
426 | BOOL past_hname = FALSE; |
427 | BOOL in_b_val = FALSE; | |
428 | int where = PDKIM_HDR_LIMBO; | |
429 | int i; | |
430 | ||
ca9cb170 | 431 | sig = store_get(sizeof(pdkim_signature)); |
abe1010c | 432 | memset(sig, 0, sizeof(pdkim_signature)); |
3045f050 JH |
433 | sig->bodylength = -1; |
434 | ||
07eeb4df | 435 | /* Set so invalid/missing data error display is accurate */ |
436 | sig->algo = -1; | |
437 | sig->version = 0; | |
438 | ||
ca9cb170 | 439 | q = sig->rawsig_no_b_val = store_get(Ustrlen(raw_hdr)+1); |
80a47a2c | 440 | |
3045f050 JH |
441 | for (p = raw_hdr; ; p++) |
442 | { | |
443 | char c = *p; | |
80a47a2c | 444 | |
3045f050 JH |
445 | /* Ignore FWS */ |
446 | if (c == '\r' || c == '\n') | |
447 | goto NEXT_CHAR; | |
80a47a2c | 448 | |
3045f050 JH |
449 | /* Fast-forward through header name */ |
450 | if (!past_hname) | |
451 | { | |
452 | if (c == ':') past_hname = TRUE; | |
453 | goto NEXT_CHAR; | |
80a47a2c TK |
454 | } |
455 | ||
3045f050 JH |
456 | if (where == PDKIM_HDR_LIMBO) |
457 | { | |
458 | /* In limbo, just wait for a tag-char to appear */ | |
459 | if (!(c >= 'a' && c <= 'z')) | |
460 | goto NEXT_CHAR; | |
80a47a2c | 461 | |
3045f050 | 462 | where = PDKIM_HDR_TAG; |
80a47a2c TK |
463 | } |
464 | ||
3045f050 JH |
465 | if (where == PDKIM_HDR_TAG) |
466 | { | |
3045f050 | 467 | if (c >= 'a' && c <= 'z') |
c2f669a4 | 468 | cur_tag = string_catn(cur_tag, &ts, &tl, p, 1); |
80a47a2c | 469 | |
3045f050 JH |
470 | if (c == '=') |
471 | { | |
ca9cb170 JH |
472 | cur_tag[tl] = '\0'; |
473 | if (Ustrcmp(cur_tag, "b") == 0) | |
3045f050 | 474 | { |
ca9cb170 | 475 | *q++ = '='; |
3045f050 JH |
476 | in_b_val = TRUE; |
477 | } | |
478 | where = PDKIM_HDR_VALUE; | |
479 | goto NEXT_CHAR; | |
80a47a2c TK |
480 | } |
481 | } | |
482 | ||
3045f050 JH |
483 | if (where == PDKIM_HDR_VALUE) |
484 | { | |
3045f050 JH |
485 | if (c == '\r' || c == '\n' || c == ' ' || c == '\t') |
486 | goto NEXT_CHAR; | |
487 | ||
488 | if (c == ';' || c == '\0') | |
489 | { | |
ca9cb170 | 490 | if (tl && vl) |
3045f050 | 491 | { |
ca9cb170 | 492 | cur_val[vl] = '\0'; |
3045f050 JH |
493 | pdkim_strtrim(cur_val); |
494 | ||
ca9cb170 | 495 | DEBUG(D_acl) debug_printf(" %s=%s\n", cur_tag, cur_val); |
3045f050 | 496 | |
ca9cb170 | 497 | switch (*cur_tag) |
3045f050 JH |
498 | { |
499 | case 'b': | |
dcd03763 JH |
500 | pdkim_decode_base64(cur_val, |
501 | cur_tag[1] == 'h' ? &sig->bodyhash : &sig->sighash); | |
3045f050 JH |
502 | break; |
503 | case 'v': | |
504 | /* We only support version 1, and that is currently the | |
505 | only version there is. */ | |
07eeb4df | 506 | sig->version = |
507 | Ustrcmp(cur_val, PDKIM_SIGNATURE_VERSION) == 0 ? 1 : -1; | |
3045f050 JH |
508 | break; |
509 | case 'a': | |
9b2583c4 | 510 | /*XXX this searches a list of combined (algo + hash-method)s */ |
3045f050 | 511 | for (i = 0; pdkim_algos[i]; i++) |
ca9cb170 | 512 | if (Ustrcmp(cur_val, pdkim_algos[i]) == 0) |
3045f050 JH |
513 | { |
514 | sig->algo = i; | |
515 | break; | |
516 | } | |
517 | break; | |
518 | case 'c': | |
519 | for (i = 0; pdkim_combined_canons[i].str; i++) | |
ca9cb170 | 520 | if (Ustrcmp(cur_val, pdkim_combined_canons[i].str) == 0) |
3045f050 JH |
521 | { |
522 | sig->canon_headers = pdkim_combined_canons[i].canon_headers; | |
523 | sig->canon_body = pdkim_combined_canons[i].canon_body; | |
524 | break; | |
525 | } | |
526 | break; | |
527 | case 'q': | |
528 | for (i = 0; pdkim_querymethods[i]; i++) | |
ca9cb170 | 529 | if (Ustrcmp(cur_val, pdkim_querymethods[i]) == 0) |
3045f050 JH |
530 | { |
531 | sig->querymethod = i; | |
532 | break; | |
533 | } | |
534 | break; | |
535 | case 's': | |
ca9cb170 | 536 | sig->selector = string_copy(cur_val); break; |
3045f050 | 537 | case 'd': |
ca9cb170 | 538 | sig->domain = string_copy(cur_val); break; |
3045f050 | 539 | case 'i': |
ca9cb170 | 540 | sig->identity = pdkim_decode_qp(cur_val); break; |
3045f050 | 541 | case 't': |
ca9cb170 | 542 | sig->created = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 543 | case 'x': |
ca9cb170 | 544 | sig->expires = strtoul(CS cur_val, NULL, 10); break; |
3045f050 | 545 | case 'l': |
ca9cb170 | 546 | sig->bodylength = strtol(CS cur_val, NULL, 10); break; |
3045f050 | 547 | case 'h': |
ca9cb170 | 548 | sig->headernames = string_copy(cur_val); break; |
3045f050 | 549 | case 'z': |
ca9cb170 | 550 | sig->copiedheaders = pdkim_decode_qp(cur_val); break; |
3045f050 | 551 | default: |
0d04a285 | 552 | DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); |
3045f050 JH |
553 | break; |
554 | } | |
555 | } | |
ca9cb170 JH |
556 | tl = 0; |
557 | vl = 0; | |
3045f050 JH |
558 | in_b_val = FALSE; |
559 | where = PDKIM_HDR_LIMBO; | |
80a47a2c | 560 | } |
3045f050 | 561 | else |
c2f669a4 | 562 | cur_val = string_catn(cur_val, &vs, &vl, p, 1); |
80a47a2c TK |
563 | } |
564 | ||
3045f050 JH |
565 | NEXT_CHAR: |
566 | if (c == '\0') | |
567 | break; | |
80a47a2c | 568 | |
3045f050 JH |
569 | if (!in_b_val) |
570 | *q++ = c; | |
80a47a2c TK |
571 | } |
572 | ||
3045f050 JH |
573 | *q = '\0'; |
574 | /* Chomp raw header. The final newline must not be added to the signature. */ | |
37f3dc43 JH |
575 | while (--q > sig->rawsig_no_b_val && (*q == '\r' || *q == '\n')) |
576 | *q = '\0'; | |
80a47a2c | 577 | |
0d04a285 | 578 | DEBUG(D_acl) |
3045f050 | 579 | { |
0d04a285 | 580 | debug_printf( |
3045f050 | 581 | "PDKIM >> Raw signature w/o b= tag value >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 582 | pdkim_quoteprint(US sig->rawsig_no_b_val, Ustrlen(sig->rawsig_no_b_val)); |
0d04a285 | 583 | debug_printf( |
dcd03763 | 584 | "PDKIM >> Sig size: %4u bits\n", (unsigned) sig->sighash.len*8); |
0d04a285 | 585 | debug_printf( |
3045f050 | 586 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 587 | } |
80a47a2c | 588 | |
9b2583c4 | 589 | /*XXX hash method: extend for sha512 */ |
7b83389d JH |
590 | if (!exim_sha_init(&sig->body_hash_ctx, |
591 | sig->algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256)) | |
592 | { | |
593 | DEBUG(D_acl) debug_printf("PDKIM: hash init internal error\n"); | |
594 | return NULL; | |
595 | } | |
3045f050 | 596 | return sig; |
80a47a2c TK |
597 | } |
598 | ||
599 | ||
600 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 601 | |
f444c2c7 | 602 | static pdkim_pubkey * |
e2e3255a | 603 | pdkim_parse_pubkey_record(pdkim_ctx *ctx, const uschar *raw_record) |
3045f050 | 604 | { |
35cf75e9 JH |
605 | const uschar * ele; |
606 | int sep = ';'; | |
607 | pdkim_pubkey * pub; | |
80a47a2c | 608 | |
ca9cb170 | 609 | pub = store_get(sizeof(pdkim_pubkey)); |
abe1010c | 610 | memset(pub, 0, sizeof(pdkim_pubkey)); |
80a47a2c | 611 | |
35cf75e9 JH |
612 | while ((ele = string_nextinlist(&raw_record, &sep, NULL, 0))) |
613 | { | |
614 | const uschar * val; | |
615 | ||
616 | if ((val = Ustrchr(ele, '='))) | |
3045f050 | 617 | { |
35cf75e9 | 618 | int taglen = val++ - ele; |
80a47a2c | 619 | |
35cf75e9 JH |
620 | DEBUG(D_acl) debug_printf(" %.*s=%s\n", taglen, ele, val); |
621 | switch (ele[0]) | |
3045f050 | 622 | { |
35cf75e9 JH |
623 | case 'v': pub->version = val; break; |
624 | case 'h': pub->hashes = val; break; | |
625 | case 'k': break; | |
626 | case 'g': pub->granularity = val; break; | |
627 | case 'n': pub->notes = pdkim_decode_qp(val); break; | |
628 | case 'p': pdkim_decode_base64(val, &pub->key); break; | |
629 | case 's': pub->srvtype = val; break; | |
630 | case 't': if (Ustrchr(val, 'y')) pub->testing = 1; | |
631 | if (Ustrchr(val, 's')) pub->no_subdomaining = 1; | |
e21a4d00 | 632 | break; |
35cf75e9 | 633 | default: DEBUG(D_acl) debug_printf(" Unknown tag encountered\n"); break; |
80a47a2c | 634 | } |
e21a4d00 | 635 | } |
35cf75e9 | 636 | } |
80a47a2c | 637 | |
3045f050 | 638 | /* Set fallback defaults */ |
ca9cb170 | 639 | if (!pub->version ) pub->version = string_copy(PDKIM_PUB_RECORD_VERSION); |
135e9496 JH |
640 | else if (Ustrcmp(pub->version, PDKIM_PUB_RECORD_VERSION) != 0) |
641 | { | |
642 | DEBUG(D_acl) debug_printf(" Bad v= field\n"); | |
643 | return NULL; | |
644 | } | |
e21a4d00 | 645 | |
35cf75e9 | 646 | if (!pub->granularity) pub->granularity = US"*"; |
e21a4d00 | 647 | /* |
35cf75e9 | 648 | if (!pub->keytype ) pub->keytype = US"rsa"; |
e21a4d00 | 649 | */ |
35cf75e9 | 650 | if (!pub->srvtype ) pub->srvtype = US"*"; |
80a47a2c | 651 | |
3045f050 | 652 | /* p= is required */ |
2592e6c0 | 653 | if (pub->key.data) |
80a47a2c | 654 | return pub; |
3045f050 | 655 | |
135e9496 | 656 | DEBUG(D_acl) debug_printf(" Missing p= field\n"); |
3045f050 | 657 | return NULL; |
80a47a2c TK |
658 | } |
659 | ||
660 | ||
661 | /* -------------------------------------------------------------------------- */ | |
3045f050 | 662 | |
f444c2c7 | 663 | static int |
dcd03763 | 664 | pdkim_update_bodyhash(pdkim_ctx * ctx, const char * data, int len) |
3045f050 | 665 | { |
dcd03763 JH |
666 | pdkim_signature * sig; |
667 | uschar * relaxed_data = NULL; /* Cache relaxed version of data */ | |
668 | int relaxed_len = 0; | |
3045f050 JH |
669 | |
670 | /* Traverse all signatures, updating their hashes. */ | |
dcd03763 | 671 | for (sig = ctx->sig; sig; sig = sig->next) |
3045f050 JH |
672 | { |
673 | /* Defaults to simple canon (no further treatment necessary) */ | |
b78006ac JH |
674 | const uschar *canon_data = CUS data; |
675 | int canon_len = len; | |
3045f050 JH |
676 | |
677 | if (sig->canon_body == PDKIM_CANON_RELAXED) | |
678 | { | |
679 | /* Relax the line if not done already */ | |
680 | if (!relaxed_data) | |
681 | { | |
682 | BOOL seen_wsp = FALSE; | |
683 | const char *p; | |
684 | int q = 0; | |
685 | ||
d5bccfc8 JH |
686 | /* We want to be able to free this else we allocate |
687 | for the entire message which could be many MB. Since | |
688 | we don't know what allocations the SHA routines might | |
689 | do, not safe to use store_get()/store_reset(). */ | |
690 | ||
40c90bca | 691 | relaxed_data = store_malloc(len+1); |
3045f050 JH |
692 | |
693 | for (p = data; *p; p++) | |
694 | { | |
695 | char c = *p; | |
696 | if (c == '\r') | |
697 | { | |
698 | if (q > 0 && relaxed_data[q-1] == ' ') | |
699 | q--; | |
700 | } | |
701 | else if (c == '\t' || c == ' ') | |
702 | { | |
703 | c = ' '; /* Turns WSP into SP */ | |
704 | if (seen_wsp) | |
705 | continue; | |
706 | seen_wsp = TRUE; | |
707 | } | |
708 | else | |
709 | seen_wsp = FALSE; | |
710 | relaxed_data[q++] = c; | |
711 | } | |
712 | relaxed_data[q] = '\0'; | |
713 | relaxed_len = q; | |
80a47a2c | 714 | } |
3045f050 JH |
715 | canon_data = relaxed_data; |
716 | canon_len = relaxed_len; | |
80a47a2c TK |
717 | } |
718 | ||
3045f050 JH |
719 | /* Make sure we don't exceed the to-be-signed body length */ |
720 | if ( sig->bodylength >= 0 | |
721 | && sig->signed_body_bytes + (unsigned long)canon_len > sig->bodylength | |
722 | ) | |
723 | canon_len = sig->bodylength - sig->signed_body_bytes; | |
80a47a2c | 724 | |
3045f050 JH |
725 | if (canon_len > 0) |
726 | { | |
dcd03763 | 727 | exim_sha_update(&sig->body_hash_ctx, CUS canon_data, canon_len); |
3045f050 | 728 | sig->signed_body_bytes += canon_len; |
2592e6c0 | 729 | DEBUG(D_acl) pdkim_quoteprint(canon_data, canon_len); |
80a47a2c | 730 | } |
80a47a2c TK |
731 | } |
732 | ||
40c90bca | 733 | if (relaxed_data) store_free(relaxed_data); |
3045f050 | 734 | return PDKIM_OK; |
6ab02e3f | 735 | } |
80a47a2c TK |
736 | |
737 | ||
738 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 739 | |
ca9cb170 | 740 | static void |
3045f050 JH |
741 | pdkim_finish_bodyhash(pdkim_ctx *ctx) |
742 | { | |
f4d091fb | 743 | pdkim_signature *sig; |
80a47a2c | 744 | |
3045f050 | 745 | /* Traverse all signatures */ |
f4d091fb | 746 | for (sig = ctx->sig; sig; sig = sig->next) |
3045f050 | 747 | { /* Finish hashes */ |
2592e6c0 JH |
748 | blob bh; |
749 | ||
dcd03763 | 750 | exim_sha_finish(&sig->body_hash_ctx, &bh); |
3045f050 | 751 | |
0d04a285 | 752 | DEBUG(D_acl) |
3045f050 | 753 | { |
0d04a285 | 754 | debug_printf("PDKIM [%s] Body bytes hashed: %lu\n" |
e21a4d00 | 755 | "PDKIM [%s] Body hash computed: ", |
0d04a285 | 756 | sig->domain, sig->signed_body_bytes, sig->domain); |
b78006ac | 757 | pdkim_hexprint(CUS bh.data, bh.len); |
80a47a2c | 758 | } |
3045f050 JH |
759 | |
760 | /* SIGNING -------------------------------------------------------------- */ | |
e983e85a | 761 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 762 | { |
2592e6c0 | 763 | sig->bodyhash = bh; |
3045f050 JH |
764 | |
765 | /* If bodylength limit is set, and we have received less bytes | |
766 | than the requested amount, effectively remove the limit tag. */ | |
767 | if (sig->signed_body_bytes < sig->bodylength) | |
768 | sig->bodylength = -1; | |
80a47a2c | 769 | } |
3045f050 | 770 | |
3045f050 | 771 | else |
02c4f8fb JH |
772 | /* VERIFICATION --------------------------------------------------------- */ |
773 | /* Be careful that the header sig included a bodyash */ | |
774 | ||
775 | if (sig->bodyhash.data && memcmp(bh.data, sig->bodyhash.data, bh.len) == 0) | |
3045f050 | 776 | { |
0d04a285 | 777 | DEBUG(D_acl) debug_printf("PDKIM [%s] Body hash verified OK\n", sig->domain); |
80a47a2c | 778 | } |
3045f050 JH |
779 | else |
780 | { | |
0d04a285 | 781 | DEBUG(D_acl) |
3045f050 | 782 | { |
e21a4d00 | 783 | debug_printf("PDKIM [%s] Body hash signature from headers: ", sig->domain); |
dcd03763 | 784 | pdkim_hexprint(sig->bodyhash.data, sig->bodyhash.len); |
0d04a285 | 785 | debug_printf("PDKIM [%s] Body hash did NOT verify\n", sig->domain); |
3045f050 | 786 | } |
3045f050 JH |
787 | sig->verify_status = PDKIM_VERIFY_FAIL; |
788 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_BODY; | |
80a47a2c | 789 | } |
80a47a2c | 790 | } |
6ab02e3f | 791 | } |
80a47a2c TK |
792 | |
793 | ||
794 | ||
e983e85a JH |
795 | static int |
796 | pdkim_body_complete(pdkim_ctx * ctx) | |
797 | { | |
798 | pdkim_signature * sig = ctx->sig; /*XXX assumes only one sig */ | |
799 | ||
800 | /* In simple body mode, if any empty lines were buffered, | |
801 | replace with one. rfc 4871 3.4.3 */ | |
802 | /*XXX checking the signed-body-bytes is a gross hack; I think | |
803 | it indicates that all linebreaks should be buffered, including | |
804 | the one terminating a text line */ | |
805 | ||
806 | if ( sig && sig->canon_body == PDKIM_CANON_SIMPLE | |
807 | && sig->signed_body_bytes == 0 | |
808 | && ctx->num_buffered_crlf > 0 | |
809 | ) | |
810 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
811 | ||
812 | ctx->flags |= PDKIM_SEEN_EOD; | |
813 | ctx->linebuf_offset = 0; | |
814 | return PDKIM_OK; | |
815 | } | |
816 | ||
817 | ||
818 | ||
80a47a2c | 819 | /* -------------------------------------------------------------------------- */ |
e983e85a | 820 | /* Call from pdkim_feed below for processing complete body lines */ |
3045f050 | 821 | |
0d04a285 | 822 | static int |
3045f050 JH |
823 | pdkim_bodyline_complete(pdkim_ctx *ctx) |
824 | { | |
825 | char *p = ctx->linebuf; | |
826 | int n = ctx->linebuf_offset; | |
c14470c3 | 827 | pdkim_signature *sig = ctx->sig; /*XXX assumes only one sig */ |
3045f050 JH |
828 | |
829 | /* Ignore extra data if we've seen the end-of-data marker */ | |
e983e85a | 830 | if (ctx->flags & PDKIM_SEEN_EOD) goto BAIL; |
3045f050 JH |
831 | |
832 | /* We've always got one extra byte to stuff a zero ... */ | |
0d04a285 | 833 | ctx->linebuf[ctx->linebuf_offset] = '\0'; |
3045f050 | 834 | |
0d04a285 | 835 | /* Terminate on EOD marker */ |
e983e85a | 836 | if (ctx->flags & PDKIM_DOT_TERM) |
3045f050 | 837 | { |
b895f4b2 | 838 | if (memcmp(p, ".\r\n", 3) == 0) |
e983e85a | 839 | return pdkim_body_complete(ctx); |
0d04a285 | 840 | |
e983e85a JH |
841 | /* Unstuff dots */ |
842 | if (memcmp(p, "..", 2) == 0) | |
843 | { | |
844 | p++; | |
845 | n--; | |
846 | } | |
80a47a2c TK |
847 | } |
848 | ||
3045f050 JH |
849 | /* Empty lines need to be buffered until we find a non-empty line */ |
850 | if (memcmp(p, "\r\n", 2) == 0) | |
851 | { | |
852 | ctx->num_buffered_crlf++; | |
853 | goto BAIL; | |
80a47a2c TK |
854 | } |
855 | ||
c14470c3 | 856 | if (sig && sig->canon_body == PDKIM_CANON_RELAXED) |
3045f050 JH |
857 | { |
858 | /* Lines with just spaces need to be buffered too */ | |
859 | char *check = p; | |
860 | while (memcmp(check, "\r\n", 2) != 0) | |
861 | { | |
862 | char c = *check; | |
6a11a9e6 | 863 | |
3045f050 JH |
864 | if (c != '\t' && c != ' ') |
865 | goto PROCESS; | |
866 | check++; | |
6a11a9e6 JH |
867 | } |
868 | ||
3045f050 JH |
869 | ctx->num_buffered_crlf++; |
870 | goto BAIL; | |
871 | } | |
6a11a9e6 | 872 | |
3045f050 JH |
873 | PROCESS: |
874 | /* At this point, we have a non-empty line, so release the buffered ones. */ | |
875 | while (ctx->num_buffered_crlf) | |
876 | { | |
877 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
878 | ctx->num_buffered_crlf--; | |
80a47a2c TK |
879 | } |
880 | ||
3045f050 | 881 | pdkim_update_bodyhash(ctx, p, n); |
80a47a2c | 882 | |
3045f050 JH |
883 | BAIL: |
884 | ctx->linebuf_offset = 0; | |
885 | return PDKIM_OK; | |
80a47a2c TK |
886 | } |
887 | ||
888 | ||
889 | /* -------------------------------------------------------------------------- */ | |
890 | /* Callback from pdkim_feed below for processing complete headers */ | |
891 | #define DKIM_SIGNATURE_HEADERNAME "DKIM-Signature:" | |
3045f050 | 892 | |
f444c2c7 | 893 | static int |
2c0f3ea1 | 894 | pdkim_header_complete(pdkim_ctx * ctx) |
3045f050 | 895 | { |
2c0f3ea1 JH |
896 | pdkim_signature * sig, * last_sig; |
897 | ||
3045f050 | 898 | /* Special case: The last header can have an extra \r appended */ |
ca9cb170 JH |
899 | if ( (ctx->cur_header_len > 1) && |
900 | (ctx->cur_header[(ctx->cur_header_len)-1] == '\r') ) | |
901 | --ctx->cur_header_len; | |
902 | ctx->cur_header[ctx->cur_header_len] = '\0'; | |
80a47a2c | 903 | |
2c0f3ea1 | 904 | if (++ctx->num_headers > PDKIM_MAX_HEADERS) goto BAIL; |
80a47a2c | 905 | |
3045f050 | 906 | /* SIGNING -------------------------------------------------------------- */ |
e983e85a | 907 | if (ctx->flags & PDKIM_MODE_SIGN) |
0d04a285 | 908 | for (sig = ctx->sig; sig; sig = sig->next) /* Traverse all signatures */ |
80a47a2c | 909 | |
ab9152ff | 910 | /* Add header to the signed headers list (in reverse order) */ |
ca9cb170 JH |
911 | sig->headers = pdkim_prepend_stringlist(sig->headers, |
912 | ctx->cur_header); | |
94431adb | 913 | |
0d04a285 | 914 | /* VERIFICATION ----------------------------------------------------------- */ |
3045f050 | 915 | /* DKIM-Signature: headers are added to the verification list */ |
e983e85a | 916 | else |
3045f050 | 917 | { |
f6ee24a2 | 918 | #ifdef notdef |
bd8fbe36 JH |
919 | DEBUG(D_acl) |
920 | { | |
921 | debug_printf("PDKIM >> raw hdr: "); | |
2c0f3ea1 | 922 | pdkim_quoteprint(CUS ctx->cur_header, ctx->cur_header_len); |
bd8fbe36 | 923 | } |
f6ee24a2 | 924 | #endif |
e2e3255a | 925 | if (strncasecmp(CCS ctx->cur_header, |
3045f050 | 926 | DKIM_SIGNATURE_HEADERNAME, |
e2e3255a | 927 | Ustrlen(DKIM_SIGNATURE_HEADERNAME)) == 0) |
3045f050 | 928 | { |
02c4f8fb JH |
929 | /* Create and chain new signature block. We could error-check for all |
930 | required tags here, but prefer to create the internal sig and expicitly | |
931 | fail verification of it later. */ | |
80a47a2c | 932 | |
0d04a285 | 933 | DEBUG(D_acl) debug_printf( |
3045f050 | 934 | "PDKIM >> Found sig, trying to parse >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
3045f050 | 935 | |
2c0f3ea1 | 936 | sig = pdkim_parse_sig_header(ctx, ctx->cur_header); |
02c4f8fb JH |
937 | |
938 | if (!(last_sig = ctx->sig)) | |
2c0f3ea1 | 939 | ctx->sig = sig; |
02c4f8fb | 940 | else |
3045f050 | 941 | { |
02c4f8fb | 942 | while (last_sig->next) last_sig = last_sig->next; |
2c0f3ea1 | 943 | last_sig->next = sig; |
80a47a2c TK |
944 | } |
945 | } | |
37f8b554 | 946 | |
eea19017 JH |
947 | /* all headers are stored for signature verification */ |
948 | ctx->headers = pdkim_prepend_stringlist(ctx->headers, ctx->cur_header); | |
80a47a2c TK |
949 | } |
950 | ||
3045f050 | 951 | BAIL: |
2c0f3ea1 | 952 | ctx->cur_header[ctx->cur_header_len = 0] = '\0'; /* leave buffer for reuse */ |
3045f050 | 953 | return PDKIM_OK; |
6ab02e3f | 954 | } |
80a47a2c TK |
955 | |
956 | ||
957 | ||
958 | /* -------------------------------------------------------------------------- */ | |
959 | #define HEADER_BUFFER_FRAG_SIZE 256 | |
3045f050 JH |
960 | |
961 | DLLEXPORT int | |
ef698bf6 | 962 | pdkim_feed(pdkim_ctx * ctx, uschar * data, int len) |
3045f050 | 963 | { |
02c4f8fb | 964 | int p, rc; |
3045f050 | 965 | |
e983e85a JH |
966 | /* Alternate EOD signal, used in non-dotstuffing mode */ |
967 | if (!data) | |
968 | pdkim_body_complete(ctx); | |
969 | ||
10c50704 | 970 | else for (p = 0; p<len; p++) |
3045f050 | 971 | { |
ca9cb170 | 972 | uschar c = data[p]; |
3045f050 | 973 | |
e983e85a | 974 | if (ctx->flags & PDKIM_PAST_HDRS) |
3045f050 | 975 | { |
b895f4b2 JH |
976 | if (c == '\n' && !(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */ |
977 | { | |
978 | ctx->linebuf[ctx->linebuf_offset++] = '\r'; | |
979 | if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1) | |
980 | return PDKIM_ERR_LONG_LINE; | |
981 | } | |
982 | ||
3045f050 | 983 | /* Processing body byte */ |
0d04a285 | 984 | ctx->linebuf[ctx->linebuf_offset++] = c; |
b895f4b2 JH |
985 | if (c == '\r') |
986 | ctx->flags |= PDKIM_SEEN_CR; | |
987 | else if (c == '\n') | |
3045f050 | 988 | { |
b895f4b2 JH |
989 | ctx->flags &= ~PDKIM_SEEN_CR; |
990 | if ((rc = pdkim_bodyline_complete(ctx)) != PDKIM_OK) | |
991 | return rc; | |
80a47a2c | 992 | } |
b895f4b2 JH |
993 | |
994 | if (ctx->linebuf_offset == PDKIM_MAX_BODY_LINE_LEN-1) | |
3045f050 | 995 | return PDKIM_ERR_LONG_LINE; |
80a47a2c | 996 | } |
3045f050 JH |
997 | else |
998 | { | |
999 | /* Processing header byte */ | |
b895f4b2 JH |
1000 | if (c == '\r') |
1001 | ctx->flags |= PDKIM_SEEN_CR; | |
1002 | else if (c == '\n') | |
3045f050 | 1003 | { |
b895f4b2 JH |
1004 | if (!(ctx->flags & PDKIM_SEEN_CR)) /* emulate the CR */ |
1005 | ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, | |
1006 | &ctx->cur_header_len, CUS "\r", 1); | |
1007 | ||
02c4f8fb | 1008 | if (ctx->flags & PDKIM_SEEN_LF) /* Seen last header line */ |
b895f4b2 | 1009 | { |
02c4f8fb JH |
1010 | if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK) |
1011 | return rc; | |
b895f4b2 | 1012 | |
863bd541 | 1013 | ctx->flags = (ctx->flags & ~(PDKIM_SEEN_LF|PDKIM_SEEN_CR)) | PDKIM_PAST_HDRS; |
b895f4b2 | 1014 | DEBUG(D_acl) debug_printf( |
02c4f8fb | 1015 | "PDKIM >> Body data for hash, canonicalized >>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
b895f4b2 | 1016 | continue; |
3045f050 | 1017 | } |
b895f4b2 | 1018 | else |
863bd541 | 1019 | ctx->flags = (ctx->flags & ~PDKIM_SEEN_CR) | PDKIM_SEEN_LF; |
b895f4b2 JH |
1020 | } |
1021 | else if (ctx->flags & PDKIM_SEEN_LF) | |
1022 | { | |
02c4f8fb JH |
1023 | if (!(c == '\t' || c == ' ')) /* End of header */ |
1024 | if ((rc = pdkim_header_complete(ctx)) != PDKIM_OK) | |
1025 | return rc; | |
b895f4b2 | 1026 | ctx->flags &= ~PDKIM_SEEN_LF; |
80a47a2c | 1027 | } |
3045f050 | 1028 | |
ca9cb170 | 1029 | if (ctx->cur_header_len < PDKIM_MAX_HEADER_LEN) |
c2f669a4 | 1030 | ctx->cur_header = string_catn(ctx->cur_header, &ctx->cur_header_size, |
e2e3255a | 1031 | &ctx->cur_header_len, CUS &data[p], 1); |
80a47a2c TK |
1032 | } |
1033 | } | |
3045f050 | 1034 | return PDKIM_OK; |
6ab02e3f | 1035 | } |
80a47a2c | 1036 | |
ca9cb170 JH |
1037 | |
1038 | ||
1039 | /* Extend a grwong header with a continuation-linebreak */ | |
1040 | static uschar * | |
1041 | pdkim_hdr_cont(uschar * str, int * size, int * ptr, int * col) | |
1042 | { | |
1043 | *col = 1; | |
c2f669a4 | 1044 | return string_catn(str, size, ptr, US"\r\n\t", 3); |
ca9cb170 JH |
1045 | } |
1046 | ||
1047 | ||
1048 | ||
05b7d6de JB |
1049 | /* |
1050 | * RFC 5322 specifies that header line length SHOULD be no more than 78 | |
1051 | * lets make it so! | |
1052 | * pdkim_headcat | |
ca9cb170 JH |
1053 | * |
1054 | * returns uschar * (not nul-terminated) | |
05b7d6de JB |
1055 | * |
1056 | * col: this int holds and receives column number (octets since last '\n') | |
1057 | * str: partial string to append to | |
ca9cb170 JH |
1058 | * size: current buffer size for str |
1059 | * ptr: current tail-pointer for str | |
94431adb | 1060 | * pad: padding, split line or space after before or after eg: ";" |
05b7d6de JB |
1061 | * intro: - must join to payload eg "h=", usually the tag name |
1062 | * payload: eg base64 data - long data can be split arbitrarily. | |
1063 | * | |
1064 | * this code doesn't fold the header in some of the places that RFC4871 | |
1065 | * allows: As per RFC5322(2.2.3) it only folds before or after tag-value | |
1066 | * pairs and inside long values. it also always spaces or breaks after the | |
94431adb | 1067 | * "pad" |
05b7d6de JB |
1068 | * |
1069 | * no guarantees are made for output given out-of range input. like tag | |
f444c2c7 | 1070 | * names longer than 78, or bogus col. Input is assumed to be free of line breaks. |
05b7d6de JB |
1071 | */ |
1072 | ||
ca9cb170 JH |
1073 | static uschar * |
1074 | pdkim_headcat(int * col, uschar * str, int * size, int * ptr, | |
1075 | const uschar * pad, const uschar * intro, const uschar * payload) | |
3045f050 JH |
1076 | { |
1077 | size_t l; | |
1078 | ||
1079 | if (pad) | |
05b7d6de | 1080 | { |
ca9cb170 | 1081 | l = Ustrlen(pad); |
3045f050 | 1082 | if (*col + l > 78) |
ca9cb170 | 1083 | str = pdkim_hdr_cont(str, size, ptr, col); |
c2f669a4 | 1084 | str = string_catn(str, size, ptr, pad, l); |
3045f050 | 1085 | *col += l; |
05b7d6de JB |
1086 | } |
1087 | ||
ca9cb170 | 1088 | l = (pad?1:0) + (intro?Ustrlen(intro):0); |
05b7d6de | 1089 | |
3045f050 | 1090 | if (*col + l > 78) |
05b7d6de | 1091 | { /*can't fit intro - start a new line to make room.*/ |
ca9cb170 JH |
1092 | str = pdkim_hdr_cont(str, size, ptr, col); |
1093 | l = intro?Ustrlen(intro):0; | |
05b7d6de JB |
1094 | } |
1095 | ||
ca9cb170 | 1096 | l += payload ? Ustrlen(payload):0 ; |
05b7d6de | 1097 | |
3045f050 | 1098 | while (l>77) |
05b7d6de | 1099 | { /* this fragment will not fit on a single line */ |
3045f050 | 1100 | if (pad) |
05b7d6de | 1101 | { |
c2f669a4 | 1102 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1103 | *col += 1; |
1104 | pad = NULL; /* only want this once */ | |
1105 | l--; | |
05b7d6de | 1106 | } |
3045f050 JH |
1107 | |
1108 | if (intro) | |
05b7d6de | 1109 | { |
ca9cb170 | 1110 | size_t sl = Ustrlen(intro); |
3045f050 | 1111 | |
c2f669a4 | 1112 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1113 | *col += sl; |
1114 | l -= sl; | |
1115 | intro = NULL; /* only want this once */ | |
05b7d6de | 1116 | } |
3045f050 JH |
1117 | |
1118 | if (payload) | |
05b7d6de | 1119 | { |
ca9cb170 | 1120 | size_t sl = Ustrlen(payload); |
3045f050 JH |
1121 | size_t chomp = *col+sl < 77 ? sl : 78-*col; |
1122 | ||
c2f669a4 | 1123 | str = string_catn(str, size, ptr, payload, chomp); |
3045f050 JH |
1124 | *col += chomp; |
1125 | payload += chomp; | |
1126 | l -= chomp-1; | |
05b7d6de | 1127 | } |
3045f050 JH |
1128 | |
1129 | /* the while precondition tells us it didn't fit. */ | |
ca9cb170 | 1130 | str = pdkim_hdr_cont(str, size, ptr, col); |
05b7d6de | 1131 | } |
3045f050 JH |
1132 | |
1133 | if (*col + l > 78) | |
05b7d6de | 1134 | { |
ca9cb170 | 1135 | str = pdkim_hdr_cont(str, size, ptr, col); |
3045f050 | 1136 | pad = NULL; |
05b7d6de JB |
1137 | } |
1138 | ||
3045f050 | 1139 | if (pad) |
05b7d6de | 1140 | { |
c2f669a4 | 1141 | str = string_catn(str, size, ptr, US" ", 1); |
3045f050 JH |
1142 | *col += 1; |
1143 | pad = NULL; | |
05b7d6de JB |
1144 | } |
1145 | ||
3045f050 | 1146 | if (intro) |
05b7d6de | 1147 | { |
ca9cb170 | 1148 | size_t sl = Ustrlen(intro); |
3045f050 | 1149 | |
c2f669a4 | 1150 | str = string_catn(str, size, ptr, intro, sl); |
3045f050 JH |
1151 | *col += sl; |
1152 | l -= sl; | |
1153 | intro = NULL; | |
05b7d6de | 1154 | } |
3045f050 JH |
1155 | |
1156 | if (payload) | |
05b7d6de | 1157 | { |
ca9cb170 | 1158 | size_t sl = Ustrlen(payload); |
3045f050 | 1159 | |
c2f669a4 | 1160 | str = string_catn(str, size, ptr, payload, sl); |
3045f050 | 1161 | *col += sl; |
05b7d6de JB |
1162 | } |
1163 | ||
ca9cb170 | 1164 | return str; |
05b7d6de | 1165 | } |
80a47a2c | 1166 | |
3045f050 | 1167 | |
80a47a2c | 1168 | /* -------------------------------------------------------------------------- */ |
3045f050 | 1169 | |
ca9cb170 | 1170 | static uschar * |
2592e6c0 | 1171 | pdkim_create_header(pdkim_signature *sig, BOOL final) |
3045f050 | 1172 | { |
ca9cb170 JH |
1173 | uschar * base64_bh; |
1174 | uschar * base64_b; | |
3045f050 | 1175 | int col = 0; |
ca9cb170 JH |
1176 | uschar * hdr; int hdr_size = 0, hdr_len = 0; |
1177 | uschar * canon_all; int can_size = 0, can_len = 0; | |
3045f050 | 1178 | |
c2f669a4 JH |
1179 | canon_all = string_cat (NULL, &can_size, &can_len, |
1180 | pdkim_canons[sig->canon_headers]); | |
1181 | canon_all = string_catn(canon_all, &can_size, &can_len, US"/", 1); | |
1182 | canon_all = string_cat (canon_all, &can_size, &can_len, | |
1183 | pdkim_canons[sig->canon_body]); | |
ca9cb170 | 1184 | canon_all[can_len] = '\0'; |
3045f050 | 1185 | |
ca9cb170 | 1186 | hdr = string_cat(NULL, &hdr_size, &hdr_len, |
e2e3255a | 1187 | US"DKIM-Signature: v="PDKIM_SIGNATURE_VERSION); |
ca9cb170 | 1188 | col = hdr_len; |
3045f050 JH |
1189 | |
1190 | /* Required and static bits */ | |
ca9cb170 | 1191 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"a=", |
9b2583c4 | 1192 | /*XXX this is a combo of algo and hash-method */ |
ca9cb170 JH |
1193 | pdkim_algos[sig->algo]); |
1194 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"q=", | |
1195 | pdkim_querymethods[sig->querymethod]); | |
1196 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"c=", | |
1197 | canon_all); | |
1198 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"d=", | |
1199 | sig->domain); | |
1200 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"s=", | |
1201 | sig->selector); | |
1202 | ||
1203 | /* list of header names can be split between items. */ | |
3045f050 | 1204 | { |
e2e3255a | 1205 | uschar * n = string_copy(sig->headernames); |
ca9cb170 JH |
1206 | uschar * i = US"h="; |
1207 | uschar * s = US";"; | |
1208 | ||
1209 | while (*n) | |
05b7d6de | 1210 | { |
ca9cb170 | 1211 | uschar * c = Ustrchr(n, ':'); |
3045f050 | 1212 | |
ca9cb170 | 1213 | if (c) *c ='\0'; |
05b7d6de | 1214 | |
ca9cb170 JH |
1215 | if (!i) |
1216 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, NULL, US":"); | |
05b7d6de | 1217 | |
ca9cb170 | 1218 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, s, i, n); |
3045f050 | 1219 | |
ca9cb170 JH |
1220 | if (!c) |
1221 | break; | |
3045f050 | 1222 | |
ca9cb170 JH |
1223 | n = c+1; |
1224 | s = NULL; | |
1225 | i = NULL; | |
80a47a2c | 1226 | } |
ca9cb170 | 1227 | } |
05b7d6de | 1228 | |
ca9cb170 JH |
1229 | base64_bh = pdkim_encode_base64(&sig->bodyhash); |
1230 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"bh=", base64_bh); | |
3045f050 | 1231 | |
ca9cb170 JH |
1232 | /* Optional bits */ |
1233 | if (sig->identity) | |
1234 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"i=", sig->identity); | |
3045f050 | 1235 | |
ca9cb170 JH |
1236 | if (sig->created > 0) |
1237 | { | |
e2e3255a | 1238 | uschar minibuf[20]; |
3045f050 | 1239 | |
e2e3255a | 1240 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->created); |
ca9cb170 JH |
1241 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"t=", minibuf); |
1242 | } | |
3045f050 | 1243 | |
ca9cb170 JH |
1244 | if (sig->expires > 0) |
1245 | { | |
e2e3255a | 1246 | uschar minibuf[20]; |
3045f050 | 1247 | |
e2e3255a | 1248 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->expires); |
ca9cb170 JH |
1249 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"x=", minibuf); |
1250 | } | |
3045f050 | 1251 | |
ca9cb170 JH |
1252 | if (sig->bodylength >= 0) |
1253 | { | |
e2e3255a | 1254 | uschar minibuf[20]; |
80a47a2c | 1255 | |
e2e3255a | 1256 | snprintf(CS minibuf, sizeof(minibuf), "%lu", sig->bodylength); |
ca9cb170 | 1257 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"l=", minibuf); |
3045f050 | 1258 | } |
05b7d6de | 1259 | |
ca9cb170 | 1260 | /* Preliminary or final version? */ |
ea18931d JH |
1261 | if (final) |
1262 | { | |
1263 | base64_b = pdkim_encode_base64(&sig->sighash); | |
1264 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=", base64_b); | |
80a47a2c | 1265 | |
ea18931d JH |
1266 | /* add trailing semicolon: I'm not sure if this is actually needed */ |
1267 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, NULL, US";", US""); | |
1268 | } | |
1269 | else | |
1270 | { | |
1271 | /* To satisfy the rule "all surrounding whitespace [...] deleted" | |
1272 | ( RFC 6376 section 3.7 ) we ensure there is no whitespace here. Otherwise | |
1273 | the headcat routine could insert a linebreak which the relaxer would reduce | |
1274 | to a single space preceding the terminating semicolon, resulting in an | |
1275 | incorrect header-hash. */ | |
1276 | hdr = pdkim_headcat(&col, hdr, &hdr_size, &hdr_len, US";", US"b=;", US""); | |
1277 | } | |
80a47a2c | 1278 | |
ca9cb170 JH |
1279 | hdr[hdr_len] = '\0'; |
1280 | return hdr; | |
80a47a2c TK |
1281 | } |
1282 | ||
1283 | ||
cd1a5fe0 JH |
1284 | /* -------------------------------------------------------------------------- */ |
1285 | ||
1286 | static pdkim_pubkey * | |
b9df1829 JH |
1287 | pdkim_key_from_dns(pdkim_ctx * ctx, pdkim_signature * sig, ev_ctx * vctx, |
1288 | const uschar ** errstr) | |
cd1a5fe0 JH |
1289 | { |
1290 | uschar * dns_txt_name, * dns_txt_reply; | |
1291 | pdkim_pubkey * p; | |
cd1a5fe0 JH |
1292 | |
1293 | /* Fetch public key for signing domain, from DNS */ | |
1294 | ||
1295 | dns_txt_name = string_sprintf("%s._domainkey.%s.", sig->selector, sig->domain); | |
1296 | ||
1297 | dns_txt_reply = store_get(PDKIM_DNS_TXT_MAX_RECLEN); | |
1298 | memset(dns_txt_reply, 0, PDKIM_DNS_TXT_MAX_RECLEN); | |
1299 | ||
1300 | if ( ctx->dns_txt_callback(CS dns_txt_name, CS dns_txt_reply) != PDKIM_OK | |
1301 | || dns_txt_reply[0] == '\0' | |
1302 | ) | |
1303 | { | |
1304 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1305 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_UNAVAILABLE; | |
1306 | return NULL; | |
1307 | } | |
1308 | ||
1309 | DEBUG(D_acl) | |
1310 | { | |
1311 | debug_printf( | |
1312 | "PDKIM >> Parsing public key record >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n" | |
1313 | " Raw record: "); | |
1314 | pdkim_quoteprint(CUS dns_txt_reply, Ustrlen(dns_txt_reply)); | |
1315 | } | |
1316 | ||
1317 | if ( !(p = pdkim_parse_pubkey_record(ctx, CUS dns_txt_reply)) | |
1318 | || (Ustrcmp(p->srvtype, "*") != 0 && Ustrcmp(p->srvtype, "email") != 0) | |
1319 | ) | |
1320 | { | |
1321 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1322 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_DNSRECORD; | |
1323 | ||
1324 | DEBUG(D_acl) | |
1325 | { | |
1326 | if (p) | |
1327 | debug_printf(" Invalid public key service type '%s'\n", p->srvtype); | |
1328 | else | |
1329 | debug_printf(" Error while parsing public key record\n"); | |
1330 | debug_printf( | |
1331 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1332 | } | |
1333 | return NULL; | |
1334 | } | |
1335 | ||
1336 | DEBUG(D_acl) debug_printf( | |
1337 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1338 | ||
1339 | /* Import public key */ | |
9b2583c4 | 1340 | if ((*errstr = exim_dkim_verify_init(&p->key, vctx))) |
cd1a5fe0 | 1341 | { |
b9df1829 | 1342 | DEBUG(D_acl) debug_printf("verify_init: %s\n", *errstr); |
cd1a5fe0 JH |
1343 | sig->verify_status = PDKIM_VERIFY_INVALID; |
1344 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_PUBKEY_IMPORT; | |
1345 | return NULL; | |
1346 | } | |
1347 | ||
1348 | return p; | |
1349 | } | |
1350 | ||
1351 | ||
80a47a2c | 1352 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
1353 | |
1354 | DLLEXPORT int | |
b9df1829 JH |
1355 | pdkim_feed_finish(pdkim_ctx * ctx, pdkim_signature ** return_signatures, |
1356 | const uschar ** err) | |
3045f050 JH |
1357 | { |
1358 | pdkim_signature *sig = ctx->sig; | |
3045f050 JH |
1359 | |
1360 | /* Check if we must still flush a (partial) header. If that is the | |
1361 | case, the message has no body, and we must compute a body hash | |
1362 | out of '<CR><LF>' */ | |
ca9cb170 | 1363 | if (ctx->cur_header && ctx->cur_header_len) |
3045f050 JH |
1364 | { |
1365 | int rc = pdkim_header_complete(ctx); | |
1366 | if (rc != PDKIM_OK) return rc; | |
1367 | pdkim_update_bodyhash(ctx, "\r\n", 2); | |
80a47a2c | 1368 | } |
3045f050 | 1369 | else |
0d04a285 | 1370 | DEBUG(D_acl) debug_printf( |
3045f050 | 1371 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1372 | |
3045f050 | 1373 | /* Build (and/or evaluate) body hash */ |
ca9cb170 | 1374 | pdkim_finish_bodyhash(ctx); |
80a47a2c | 1375 | |
3045f050 JH |
1376 | while (sig) |
1377 | { | |
9b2583c4 | 1378 | /*XXX bool probably not enough */ |
2592e6c0 JH |
1379 | BOOL is_sha1 = sig->algo == PDKIM_ALGO_RSA_SHA1; |
1380 | hctx hhash_ctx; | |
ad6f5499 | 1381 | uschar * sig_hdr = US""; |
2592e6c0 JH |
1382 | blob hhash; |
1383 | blob hdata; | |
cb224393 | 1384 | int hdata_alloc = 0; |
cb224393 | 1385 | |
2592e6c0 JH |
1386 | hdata.data = NULL; |
1387 | hdata.len = 0; | |
1388 | ||
7b83389d JH |
1389 | if (!exim_sha_init(&hhash_ctx, is_sha1 ? HASH_SHA1 : HASH_SHA256)) |
1390 | { | |
1391 | DEBUG(D_acl) debug_printf("PDKIM: hask setup internal error\n"); | |
1392 | break; | |
1393 | } | |
80a47a2c | 1394 | |
0d04a285 | 1395 | DEBUG(D_acl) debug_printf( |
328c5688 | 1396 | "PDKIM >> Header data for hash, canonicalized, in sequence >>>>>>>>>>>>\n"); |
3045f050 JH |
1397 | |
1398 | /* SIGNING ---------------------------------------------------------------- */ | |
1399 | /* When signing, walk through our header list and add them to the hash. As we | |
8ef02a06 JH |
1400 | go, construct a list of the header's names to use for the h= parameter. |
1401 | Then append to that list any remaining header names for which there was no | |
1402 | header to sign. */ | |
3045f050 | 1403 | |
e983e85a | 1404 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1405 | { |
10c50704 JH |
1406 | uschar * headernames = NULL; /* Collected signed header names */ |
1407 | int hs = 0, hl = 0; | |
3045f050 | 1408 | pdkim_stringlist *p; |
8ef02a06 JH |
1409 | const uschar * l; |
1410 | uschar * s; | |
1411 | int sep = 0; | |
3045f050 JH |
1412 | |
1413 | for (p = sig->headers; p; p = p->next) | |
ab9152ff JH |
1414 | if (header_name_match(p->value, sig->sign_headers) == PDKIM_OK) |
1415 | { | |
1416 | uschar * rh; | |
1417 | /* Collect header names (Note: colon presence is guaranteed here) */ | |
1418 | uschar * q = Ustrchr(p->value, ':'); | |
3045f050 | 1419 | |
c2f669a4 | 1420 | headernames = string_catn(headernames, &hs, &hl, |
ca9cb170 | 1421 | p->value, (q - US p->value) + (p->next ? 1 : 0)); |
3045f050 | 1422 | |
ab9152ff | 1423 | rh = sig->canon_headers == PDKIM_CANON_RELAXED |
ea18931d | 1424 | ? pdkim_relax_header(p->value, TRUE) /* cook header for relaxed canon */ |
ca9cb170 | 1425 | : string_copy(CUS p->value); /* just copy it for simple canon */ |
3045f050 | 1426 | |
ab9152ff | 1427 | /* Feed header to the hash algorithm */ |
e2e3255a | 1428 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); |
f444c2c7 | 1429 | |
ab9152ff | 1430 | /* Remember headers block for signing (when the library cannot do incremental) */ |
9b2583c4 | 1431 | (void) exim_dkim_data_append(&hdata, &hdata_alloc, rh); |
3045f050 | 1432 | |
ab9152ff JH |
1433 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); |
1434 | } | |
8ef02a06 | 1435 | |
ca9cb170 | 1436 | l = sig->sign_headers; |
8ef02a06 JH |
1437 | while((s = string_nextinlist(&l, &sep, NULL, 0))) |
1438 | if (*s != '_') | |
ab9152ff | 1439 | { /*SSS string_append_listele() */ |
ca9cb170 | 1440 | if (hl > 0 && headernames[hl-1] != ':') |
c2f669a4 | 1441 | headernames = string_catn(headernames, &hs, &hl, US":", 1); |
ca9cb170 | 1442 | |
c2f669a4 | 1443 | headernames = string_cat(headernames, &hs, &hl, s); |
8ef02a06 | 1444 | } |
ca9cb170 JH |
1445 | headernames[hl] = '\0'; |
1446 | ||
1447 | /* Copy headernames to signature struct */ | |
1448 | sig->headernames = headernames; | |
ca9cb170 JH |
1449 | |
1450 | /* Create signature header with b= omitted */ | |
1451 | sig_hdr = pdkim_create_header(sig, FALSE); | |
80a47a2c | 1452 | } |
37f8b554 | 1453 | |
3045f050 JH |
1454 | /* VERIFICATION ----------------------------------------------------------- */ |
1455 | /* When verifying, walk through the header name list in the h= parameter and | |
1456 | add the headers to the hash in that order. */ | |
1457 | else | |
1458 | { | |
10c50704 | 1459 | uschar * p = sig->headernames; |
2592e6c0 JH |
1460 | uschar * q; |
1461 | pdkim_stringlist * hdrs; | |
3045f050 | 1462 | |
10c50704 | 1463 | if (p) |
3045f050 | 1464 | { |
10c50704 | 1465 | /* clear tags */ |
3045f050 | 1466 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) |
10c50704 | 1467 | hdrs->tag = 0; |
3045f050 | 1468 | |
10c50704 JH |
1469 | p = string_copy(p); |
1470 | while(1) | |
1471 | { | |
1472 | if ((q = Ustrchr(p, ':'))) | |
1473 | *q = '\0'; | |
1474 | ||
1475 | /*XXX walk the list of headers in same order as received. */ | |
1476 | for (hdrs = ctx->headers; hdrs; hdrs = hdrs->next) | |
1477 | if ( hdrs->tag == 0 | |
4dc2379a | 1478 | && strncasecmp(CCS hdrs->value, CCS p, Ustrlen(p)) == 0 |
10c50704 JH |
1479 | && (hdrs->value)[Ustrlen(p)] == ':' |
1480 | ) | |
1481 | { | |
1482 | /* cook header for relaxed canon, or just copy it for simple */ | |
1483 | ||
1484 | uschar * rh = sig->canon_headers == PDKIM_CANON_RELAXED | |
ea18931d | 1485 | ? pdkim_relax_header(hdrs->value, TRUE) |
10c50704 JH |
1486 | : string_copy(CUS hdrs->value); |
1487 | ||
1488 | /* Feed header to the hash algorithm */ | |
1489 | exim_sha_update(&hhash_ctx, CUS rh, Ustrlen(rh)); | |
1490 | ||
1491 | DEBUG(D_acl) pdkim_quoteprint(rh, Ustrlen(rh)); | |
1492 | hdrs->tag = 1; | |
1493 | break; | |
1494 | } | |
3045f050 | 1495 | |
10c50704 JH |
1496 | if (!q) break; |
1497 | p = q+1; | |
1498 | } | |
3045f050 | 1499 | |
10c50704 | 1500 | sig_hdr = string_copy(sig->rawsig_no_b_val); |
80a47a2c | 1501 | } |
80a47a2c TK |
1502 | } |
1503 | ||
0d04a285 | 1504 | DEBUG(D_acl) debug_printf( |
3045f050 | 1505 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1506 | |
3045f050 JH |
1507 | /* Relax header if necessary */ |
1508 | if (sig->canon_headers == PDKIM_CANON_RELAXED) | |
ea18931d | 1509 | sig_hdr = pdkim_relax_header(sig_hdr, FALSE); |
80a47a2c | 1510 | |
0d04a285 | 1511 | DEBUG(D_acl) |
3045f050 | 1512 | { |
0d04a285 | 1513 | debug_printf( |
3045f050 | 1514 | "PDKIM >> Signed DKIM-Signature header, canonicalized >>>>>>>>>>>>>>>>>\n"); |
e2e3255a | 1515 | pdkim_quoteprint(CUS sig_hdr, Ustrlen(sig_hdr)); |
0d04a285 | 1516 | debug_printf( |
3045f050 | 1517 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
80a47a2c | 1518 | } |
3045f050 JH |
1519 | |
1520 | /* Finalize header hash */ | |
e2e3255a | 1521 | exim_sha_update(&hhash_ctx, CUS sig_hdr, Ustrlen(sig_hdr)); |
2592e6c0 | 1522 | exim_sha_finish(&hhash_ctx, &hhash); |
3045f050 | 1523 | |
f444c2c7 JH |
1524 | DEBUG(D_acl) |
1525 | { | |
e21a4d00 | 1526 | debug_printf("PDKIM [%s] Header hash computed: ", sig->domain); |
2592e6c0 | 1527 | pdkim_hexprint(hhash.data, hhash.len); |
80a47a2c TK |
1528 | } |
1529 | ||
2592e6c0 | 1530 | /* Remember headers block for signing (when the library cannot do incremental) */ |
9b2583c4 | 1531 | /*XXX is this assuing algo == RSA? */ |
e983e85a | 1532 | if (ctx->flags & PDKIM_MODE_SIGN) |
9b2583c4 | 1533 | (void) exim_dkim_data_append(&hdata, &hdata_alloc, US sig_hdr); |
f444c2c7 | 1534 | |
3045f050 | 1535 | /* SIGNING ---------------------------------------------------------------- */ |
e983e85a | 1536 | if (ctx->flags & PDKIM_MODE_SIGN) |
3045f050 | 1537 | { |
2592e6c0 | 1538 | es_ctx sctx; |
f444c2c7 JH |
1539 | |
1540 | /* Import private key */ | |
9b2583c4 JH |
1541 | /*XXX extend for non-RSA algos */ |
1542 | if ((*err = exim_dkim_signing_init(US sig->rsa_privkey, &sctx))) | |
f444c2c7 | 1543 | { |
b9df1829 | 1544 | DEBUG(D_acl) debug_printf("signing_init: %s\n", *err); |
f444c2c7 JH |
1545 | return PDKIM_ERR_RSA_PRIVKEY; |
1546 | } | |
80a47a2c | 1547 | |
2592e6c0 JH |
1548 | /* Do signing. With OpenSSL we are signing the hash of headers just |
1549 | calculated, with GnuTLS we have to sign an entire block of headers | |
1550 | (due to available interfaces) and it recalculates the hash internally. */ | |
f444c2c7 | 1551 | |
2592e6c0 JH |
1552 | #if defined(RSA_OPENSSL) || defined(RSA_GCRYPT) |
1553 | hdata = hhash; | |
f444c2c7 JH |
1554 | #endif |
1555 | ||
9b2583c4 JH |
1556 | /*XXX extend for non-RSA algos */ |
1557 | /*XXX oddly the dkim rfc does _not_ say what variant (sha1 or sha256) of | |
1558 | RSA signing should be done. We use the same variant as the hash-method. */ | |
1559 | ||
1560 | if ((*err = exim_dkim_sign(&sctx, is_sha1, &hdata, &sig->sighash))) | |
f444c2c7 | 1561 | { |
b9df1829 | 1562 | DEBUG(D_acl) debug_printf("signing: %s\n", *err); |
f444c2c7 JH |
1563 | return PDKIM_ERR_RSA_SIGNING; |
1564 | } | |
80a47a2c | 1565 | |
0d04a285 | 1566 | DEBUG(D_acl) |
3045f050 | 1567 | { |
0d04a285 | 1568 | debug_printf( "PDKIM [%s] b computed: ", sig->domain); |
dcd03763 | 1569 | pdkim_hexprint(sig->sighash.data, sig->sighash.len); |
80a47a2c | 1570 | } |
80a47a2c | 1571 | |
ca9cb170 | 1572 | sig->signature_header = pdkim_create_header(sig, TRUE); |
80a47a2c | 1573 | } |
80a47a2c | 1574 | |
3045f050 JH |
1575 | /* VERIFICATION ----------------------------------------------------------- */ |
1576 | else | |
1577 | { | |
2592e6c0 | 1578 | ev_ctx vctx; |
3045f050 | 1579 | |
07eeb4df | 1580 | /* Make sure we have all required signature tags */ |
1581 | if (!( sig->domain && *sig->domain | |
1582 | && sig->selector && *sig->selector | |
1583 | && sig->headernames && *sig->headernames | |
1584 | && sig->bodyhash.data | |
dcd03763 | 1585 | && sig->sighash.data |
07eeb4df | 1586 | && sig->algo > -1 |
1587 | && sig->version | |
1588 | ) ) | |
1589 | { | |
1590 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1591 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_SIGNATURE_ERROR; | |
1592 | ||
1593 | DEBUG(D_acl) debug_printf( | |
1594 | " Error in DKIM-Signature header: tags missing or invalid\n" | |
1595 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1596 | goto NEXT_VERIFY; | |
1597 | } | |
1598 | ||
1599 | /* Make sure sig uses supported DKIM version (only v1) */ | |
1600 | if (sig->version != 1) | |
1601 | { | |
1602 | sig->verify_status = PDKIM_VERIFY_INVALID; | |
1603 | sig->verify_ext_status = PDKIM_VERIFY_INVALID_DKIM_VERSION; | |
1604 | ||
1605 | DEBUG(D_acl) debug_printf( | |
1606 | " Error in DKIM-Signature header: unsupported DKIM version\n" | |
1607 | "PDKIM <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); | |
1608 | goto NEXT_VERIFY; | |
1609 | } | |
1610 | ||
b9df1829 | 1611 | if (!(sig->pubkey = pdkim_key_from_dns(ctx, sig, &vctx, err))) |
3045f050 | 1612 | goto NEXT_VERIFY; |
80a47a2c | 1613 | |
135e9496 JH |
1614 | /* If the pubkey limits to a list of specific hashes, ignore sigs that |
1615 | do not have the hash part of the sig algorithm matching */ | |
1616 | ||
1617 | if (sig->pubkey->hashes) | |
1618 | { | |
1619 | const uschar * list = sig->pubkey->hashes, * ele; | |
1620 | int sep = ':'; | |
1621 | while ((ele = string_nextinlist(&list, &sep, NULL, 0))) | |
1622 | if (Ustrcmp(ele, pdkim_algos[sig->algo] + 4) == 0) break; | |
1623 | if (!ele) | |
1624 | { | |
1625 | DEBUG(D_acl) debug_printf("pubkey h=%s vs sig a=%s\n", | |
1626 | sig->pubkey->hashes, pdkim_algos[sig->algo]); | |
1627 | sig->verify_status = PDKIM_VERIFY_FAIL; | |
1628 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_SIG_ALGO_MISMATCH; | |
1629 | goto NEXT_VERIFY; | |
1630 | } | |
1631 | } | |
1632 | ||
3045f050 | 1633 | /* Check the signature */ |
9b2583c4 JH |
1634 | /*XXX needs extension for non-RSA */ |
1635 | if ((*err = exim_dkim_verify(&vctx, is_sha1, &hhash, &sig->sighash))) | |
3045f050 | 1636 | { |
b9df1829 | 1637 | DEBUG(D_acl) debug_printf("headers verify: %s\n", *err); |
3045f050 JH |
1638 | sig->verify_status = PDKIM_VERIFY_FAIL; |
1639 | sig->verify_ext_status = PDKIM_VERIFY_FAIL_MESSAGE; | |
1640 | goto NEXT_VERIFY; | |
ff7ddfd7 TK |
1641 | } |
1642 | ||
2592e6c0 | 1643 | |
4c04137d | 1644 | /* We have a winner! (if bodyhash was correct earlier) */ |
3045f050 JH |
1645 | if (sig->verify_status == PDKIM_VERIFY_NONE) |
1646 | sig->verify_status = PDKIM_VERIFY_PASS; | |
1647 | ||
1648 | NEXT_VERIFY: | |
1649 | ||
0d04a285 | 1650 | DEBUG(D_acl) |
3045f050 | 1651 | { |
0d04a285 | 1652 | debug_printf("PDKIM [%s] signature status: %s", |
3045f050 JH |
1653 | sig->domain, pdkim_verify_status_str(sig->verify_status)); |
1654 | if (sig->verify_ext_status > 0) | |
0d04a285 | 1655 | debug_printf(" (%s)\n", |
3045f050 JH |
1656 | pdkim_verify_ext_status_str(sig->verify_ext_status)); |
1657 | else | |
0d04a285 | 1658 | debug_printf("\n"); |
80a47a2c | 1659 | } |
80a47a2c TK |
1660 | } |
1661 | ||
3045f050 | 1662 | sig = sig->next; |
80a47a2c TK |
1663 | } |
1664 | ||
3045f050 JH |
1665 | /* If requested, set return pointer to signature(s) */ |
1666 | if (return_signatures) | |
1667 | *return_signatures = ctx->sig; | |
80a47a2c | 1668 | |
3045f050 | 1669 | return PDKIM_OK; |
80a47a2c TK |
1670 | } |
1671 | ||
1672 | ||
1673 | /* -------------------------------------------------------------------------- */ | |
3045f050 JH |
1674 | |
1675 | DLLEXPORT pdkim_ctx * | |
e983e85a | 1676 | pdkim_init_verify(int(*dns_txt_callback)(char *, char *), BOOL dot_stuffing) |
3045f050 | 1677 | { |
ca9cb170 | 1678 | pdkim_ctx * ctx; |
3045f050 | 1679 | |
ca9cb170 | 1680 | ctx = store_get(sizeof(pdkim_ctx)); |
abe1010c | 1681 | memset(ctx, 0, sizeof(pdkim_ctx)); |
3045f050 | 1682 | |
e983e85a | 1683 | if (dot_stuffing) ctx->flags = PDKIM_DOT_TERM; |
ca9cb170 | 1684 | ctx->linebuf = store_get(PDKIM_MAX_BODY_LINE_LEN); |
3045f050 | 1685 | ctx->dns_txt_callback = dns_txt_callback; |
80a47a2c | 1686 | |
3045f050 | 1687 | return ctx; |
80a47a2c TK |
1688 | } |
1689 | ||
1690 | ||
1691 | /* -------------------------------------------------------------------------- */ | |
80a47a2c | 1692 | |
9b2583c4 JH |
1693 | /*XXX ? needs extension to cover non-RSA algo? Currently the "algo" is actually |
1694 | the combo of algo and hash-method */ | |
1695 | ||
3045f050 | 1696 | DLLEXPORT pdkim_ctx * |
cd1a5fe0 | 1697 | pdkim_init_sign(char * domain, char * selector, char * rsa_privkey, int algo, |
b9df1829 JH |
1698 | BOOL dot_stuffed, int(*dns_txt_callback)(char *, char *), |
1699 | const uschar ** errstr) | |
3045f050 | 1700 | { |
cd1a5fe0 JH |
1701 | pdkim_ctx * ctx; |
1702 | pdkim_signature * sig; | |
80a47a2c | 1703 | |
3045f050 JH |
1704 | if (!domain || !selector || !rsa_privkey) |
1705 | return NULL; | |
80a47a2c | 1706 | |
cd1a5fe0 | 1707 | ctx = store_get(sizeof(pdkim_ctx) + PDKIM_MAX_BODY_LINE_LEN + sizeof(pdkim_signature)); |
abe1010c | 1708 | memset(ctx, 0, sizeof(pdkim_ctx)); |
80a47a2c | 1709 | |
e983e85a | 1710 | ctx->flags = dot_stuffed ? PDKIM_MODE_SIGN | PDKIM_DOT_TERM : PDKIM_MODE_SIGN; |
cd1a5fe0 | 1711 | ctx->linebuf = CS (ctx+1); |
80a47a2c | 1712 | |
cd1a5fe0 JH |
1713 | DEBUG(D_acl) ctx->dns_txt_callback = dns_txt_callback; |
1714 | ||
1715 | sig = (pdkim_signature *)(ctx->linebuf + PDKIM_MAX_BODY_LINE_LEN); | |
abe1010c | 1716 | memset(sig, 0, sizeof(pdkim_signature)); |
80a47a2c | 1717 | |
3045f050 | 1718 | sig->bodylength = -1; |
3045f050 | 1719 | ctx->sig = sig; |
80a47a2c | 1720 | |
e2e3255a JH |
1721 | sig->domain = string_copy(US domain); |
1722 | sig->selector = string_copy(US selector); | |
1723 | sig->rsa_privkey = string_copy(US rsa_privkey); | |
2592e6c0 | 1724 | sig->algo = algo; |
cb224393 | 1725 | |
9b2583c4 | 1726 | /*XXX extend for sha512 */ |
7b83389d JH |
1727 | if (!exim_sha_init(&sig->body_hash_ctx, |
1728 | algo == PDKIM_ALGO_RSA_SHA1 ? HASH_SHA1 : HASH_SHA256)) | |
1729 | { | |
1730 | DEBUG(D_acl) debug_printf("PDKIM: hash setup internal error\n"); | |
1731 | return NULL; | |
1732 | } | |
1733 | ||
cd1a5fe0 JH |
1734 | DEBUG(D_acl) |
1735 | { | |
1736 | pdkim_signature s = *sig; | |
1737 | ev_ctx vctx; | |
1738 | ||
328c5688 | 1739 | debug_printf("PDKIM (checking verify key)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n"); |
b9df1829 | 1740 | if (!pdkim_key_from_dns(ctx, &s, &vctx, errstr)) |
cd1a5fe0 | 1741 | debug_printf("WARNING: bad dkim key in dns\n"); |
328c5688 | 1742 | debug_printf("PDKIM (finished checking verify key)<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n"); |
cd1a5fe0 | 1743 | } |
3045f050 | 1744 | return ctx; |
6ab02e3f | 1745 | } |
80a47a2c | 1746 | |
f444c2c7 | 1747 | |
80a47a2c | 1748 | /* -------------------------------------------------------------------------- */ |
3045f050 JH |
1749 | |
1750 | DLLEXPORT int | |
1751 | pdkim_set_optional(pdkim_ctx *ctx, | |
80a47a2c TK |
1752 | char *sign_headers, |
1753 | char *identity, | |
1754 | int canon_headers, | |
1755 | int canon_body, | |
1756 | long bodylength, | |
80a47a2c | 1757 | unsigned long created, |
3045f050 JH |
1758 | unsigned long expires) |
1759 | { | |
8ef02a06 JH |
1760 | pdkim_signature * sig = ctx->sig; |
1761 | ||
3045f050 | 1762 | if (identity) |
e2e3255a | 1763 | sig->identity = string_copy(US identity); |
80a47a2c | 1764 | |
ca9cb170 JH |
1765 | sig->sign_headers = string_copy(sign_headers |
1766 | ? US sign_headers : US PDKIM_DEFAULT_SIGN_HEADERS); | |
80a47a2c | 1767 | |
8ef02a06 JH |
1768 | sig->canon_headers = canon_headers; |
1769 | sig->canon_body = canon_body; | |
1770 | sig->bodylength = bodylength; | |
1771 | sig->created = created; | |
1772 | sig->expires = expires; | |
80a47a2c | 1773 | |
3045f050 | 1774 | return PDKIM_OK; |
6ab02e3f | 1775 | } |
3045f050 | 1776 | |
3045f050 | 1777 | |
2592e6c0 JH |
1778 | void |
1779 | pdkim_init(void) | |
1780 | { | |
9b2583c4 | 1781 | exim_dkim_init(); |
2592e6c0 JH |
1782 | } |
1783 | ||
1784 | ||
1785 | ||
f444c2c7 | 1786 | #endif /*DISABLE_DKIM*/ |