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Commit | Line | Data |
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2f47eae2 | 1 | #include "cache.h" |
b2141fc1 | 2 | #include "config.h" |
2f47eae2 JH |
3 | #include "run-command.h" |
4 | #include "strbuf.h" | |
5 | #include "gpg-interface.h" | |
6 | #include "sigchain.h" | |
4322353b | 7 | #include "tempfile.h" |
2f47eae2 JH |
8 | |
9 | static char *configured_signing_key; | |
54887b46 HJI |
10 | static enum signature_trust_level configured_min_trust_level = TRUST_UNDEFINED; |
11 | ||
58af57e1 HS |
12 | struct gpg_format { |
13 | const char *name; | |
14 | const char *program; | |
15 | const char **verify_args; | |
16 | const char **sigs; | |
17 | }; | |
18 | ||
19 | static const char *openpgp_verify_args[] = { | |
20 | "--keyid-format=long", | |
21 | NULL | |
22 | }; | |
23 | static const char *openpgp_sigs[] = { | |
24 | "-----BEGIN PGP SIGNATURE-----", | |
25 | "-----BEGIN PGP MESSAGE-----", | |
26 | NULL | |
27 | }; | |
28 | ||
1e7adb97 HS |
29 | static const char *x509_verify_args[] = { |
30 | NULL | |
31 | }; | |
32 | static const char *x509_sigs[] = { | |
33 | "-----BEGIN SIGNED MESSAGE-----", | |
34 | NULL | |
35 | }; | |
36 | ||
58af57e1 HS |
37 | static struct gpg_format gpg_format[] = { |
38 | { .name = "openpgp", .program = "gpg", | |
39 | .verify_args = openpgp_verify_args, | |
40 | .sigs = openpgp_sigs | |
41 | }, | |
1e7adb97 HS |
42 | { .name = "x509", .program = "gpgsm", |
43 | .verify_args = x509_verify_args, | |
44 | .sigs = x509_sigs | |
45 | }, | |
58af57e1 HS |
46 | }; |
47 | ||
48 | static struct gpg_format *use_format = &gpg_format[0]; | |
2f47eae2 | 49 | |
58af57e1 HS |
50 | static struct gpg_format *get_format_by_name(const char *str) |
51 | { | |
52 | int i; | |
53 | ||
54 | for (i = 0; i < ARRAY_SIZE(gpg_format); i++) | |
55 | if (!strcmp(gpg_format[i].name, str)) | |
56 | return gpg_format + i; | |
57 | return NULL; | |
58 | } | |
59 | ||
60 | static struct gpg_format *get_format_by_sig(const char *sig) | |
61 | { | |
62 | int i, j; | |
63 | ||
64 | for (i = 0; i < ARRAY_SIZE(gpg_format); i++) | |
65 | for (j = 0; gpg_format[i].sigs[j]; j++) | |
66 | if (starts_with(sig, gpg_format[i].sigs[j])) | |
67 | return gpg_format + i; | |
68 | return NULL; | |
69 | } | |
d7c67668 | 70 | |
01e57b5d MG |
71 | void signature_check_clear(struct signature_check *sigc) |
72 | { | |
88ce3ef6 ÆAB |
73 | FREE_AND_NULL(sigc->payload); |
74 | FREE_AND_NULL(sigc->gpg_output); | |
75 | FREE_AND_NULL(sigc->gpg_status); | |
76 | FREE_AND_NULL(sigc->signer); | |
77 | FREE_AND_NULL(sigc->key); | |
3daaaabe | 78 | FREE_AND_NULL(sigc->fingerprint); |
4de9394d | 79 | FREE_AND_NULL(sigc->primary_key_fingerprint); |
01e57b5d MG |
80 | } |
81 | ||
da6cf1b3 MG |
82 | /* An exclusive status -- only one of them can appear in output */ |
83 | #define GPG_STATUS_EXCLUSIVE (1<<0) | |
0b11a84e MG |
84 | /* The status includes key identifier */ |
85 | #define GPG_STATUS_KEYID (1<<1) | |
86 | /* The status includes user identifier */ | |
87 | #define GPG_STATUS_UID (1<<2) | |
3daaaabe MG |
88 | /* The status includes key fingerprints */ |
89 | #define GPG_STATUS_FINGERPRINT (1<<3) | |
54887b46 HJI |
90 | /* The status includes trust level */ |
91 | #define GPG_STATUS_TRUST_LEVEL (1<<4) | |
0b11a84e MG |
92 | |
93 | /* Short-hand for standard exclusive *SIG status with keyid & UID */ | |
94 | #define GPG_STATUS_STDSIG (GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID|GPG_STATUS_UID) | |
da6cf1b3 | 95 | |
a50e7ca3 JH |
96 | static struct { |
97 | char result; | |
98 | const char *check; | |
da6cf1b3 | 99 | unsigned int flags; |
a50e7ca3 | 100 | } sigcheck_gpg_status[] = { |
0b11a84e MG |
101 | { 'G', "GOODSIG ", GPG_STATUS_STDSIG }, |
102 | { 'B', "BADSIG ", GPG_STATUS_STDSIG }, | |
0b11a84e MG |
103 | { 'E', "ERRSIG ", GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID }, |
104 | { 'X', "EXPSIG ", GPG_STATUS_STDSIG }, | |
105 | { 'Y', "EXPKEYSIG ", GPG_STATUS_STDSIG }, | |
106 | { 'R', "REVKEYSIG ", GPG_STATUS_STDSIG }, | |
3daaaabe | 107 | { 0, "VALIDSIG ", GPG_STATUS_FINGERPRINT }, |
54887b46 HJI |
108 | { 0, "TRUST_", GPG_STATUS_TRUST_LEVEL }, |
109 | }; | |
110 | ||
111 | static struct { | |
112 | const char *key; | |
113 | enum signature_trust_level value; | |
114 | } sigcheck_gpg_trust_level[] = { | |
115 | { "UNDEFINED", TRUST_UNDEFINED }, | |
116 | { "NEVER", TRUST_NEVER }, | |
117 | { "MARGINAL", TRUST_MARGINAL }, | |
118 | { "FULLY", TRUST_FULLY }, | |
119 | { "ULTIMATE", TRUST_ULTIMATE }, | |
a50e7ca3 JH |
120 | }; |
121 | ||
392b862e HJI |
122 | static void replace_cstring(char **field, const char *line, const char *next) |
123 | { | |
124 | free(*field); | |
125 | ||
126 | if (line && next) | |
127 | *field = xmemdupz(line, next - line); | |
128 | else | |
129 | *field = NULL; | |
130 | } | |
131 | ||
54887b46 HJI |
132 | static int parse_gpg_trust_level(const char *level, |
133 | enum signature_trust_level *res) | |
134 | { | |
135 | size_t i; | |
136 | ||
137 | for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_trust_level); i++) { | |
138 | if (!strcmp(sigcheck_gpg_trust_level[i].key, level)) { | |
139 | *res = sigcheck_gpg_trust_level[i].value; | |
140 | return 0; | |
141 | } | |
142 | } | |
143 | return 1; | |
144 | } | |
145 | ||
fbd0f166 | 146 | static void parse_gpg_output(struct signature_check *sigc) |
a50e7ca3 JH |
147 | { |
148 | const char *buf = sigc->gpg_status; | |
da6cf1b3 | 149 | const char *line, *next; |
4de9394d | 150 | int i, j; |
da6cf1b3 MG |
151 | int seen_exclusive_status = 0; |
152 | ||
153 | /* Iterate over all lines */ | |
154 | for (line = buf; *line; line = strchrnul(line+1, '\n')) { | |
155 | while (*line == '\n') | |
156 | line++; | |
64c45dc7 SR |
157 | if (!*line) |
158 | break; | |
159 | ||
da6cf1b3 MG |
160 | /* Skip lines that don't start with GNUPG status */ |
161 | if (!skip_prefix(line, "[GNUPG:] ", &line)) | |
162 | continue; | |
163 | ||
164 | /* Iterate over all search strings */ | |
165 | for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) { | |
166 | if (skip_prefix(line, sigcheck_gpg_status[i].check, &line)) { | |
54887b46 HJI |
167 | /* |
168 | * GOODSIG, BADSIG etc. can occur only once for | |
169 | * each signature. Therefore, if we had more | |
170 | * than one then we're dealing with multiple | |
171 | * signatures. We don't support them | |
172 | * currently, and they're rather hard to | |
173 | * create, so something is likely fishy and we | |
174 | * should reject them altogether. | |
175 | */ | |
da6cf1b3 | 176 | if (sigcheck_gpg_status[i].flags & GPG_STATUS_EXCLUSIVE) { |
02561896 | 177 | if (seen_exclusive_status++) |
54887b46 | 178 | goto error; |
da6cf1b3 MG |
179 | } |
180 | ||
3daaaabe MG |
181 | if (sigcheck_gpg_status[i].result) |
182 | sigc->result = sigcheck_gpg_status[i].result; | |
0b11a84e MG |
183 | /* Do we have key information? */ |
184 | if (sigcheck_gpg_status[i].flags & GPG_STATUS_KEYID) { | |
da6cf1b3 | 185 | next = strchrnul(line, ' '); |
392b862e | 186 | replace_cstring(&sigc->key, line, next); |
0b11a84e MG |
187 | /* Do we have signer information? */ |
188 | if (*next && (sigcheck_gpg_status[i].flags & GPG_STATUS_UID)) { | |
da6cf1b3 MG |
189 | line = next + 1; |
190 | next = strchrnul(line, '\n'); | |
392b862e | 191 | replace_cstring(&sigc->signer, line, next); |
da6cf1b3 MG |
192 | } |
193 | } | |
54887b46 HJI |
194 | |
195 | /* Do we have trust level? */ | |
196 | if (sigcheck_gpg_status[i].flags & GPG_STATUS_TRUST_LEVEL) { | |
197 | /* | |
198 | * GPG v1 and v2 differs in how the | |
199 | * TRUST_ lines are written. Some | |
200 | * trust lines contain no additional | |
201 | * space-separated information for v1. | |
202 | */ | |
203 | size_t trust_size = strcspn(line, " \n"); | |
204 | char *trust = xmemdupz(line, trust_size); | |
205 | ||
206 | if (parse_gpg_trust_level(trust, &sigc->trust_level)) { | |
207 | free(trust); | |
208 | goto error; | |
209 | } | |
210 | free(trust); | |
211 | } | |
212 | ||
3daaaabe MG |
213 | /* Do we have fingerprint? */ |
214 | if (sigcheck_gpg_status[i].flags & GPG_STATUS_FINGERPRINT) { | |
67a6ea63 HJI |
215 | const char *limit; |
216 | char **field; | |
217 | ||
3daaaabe | 218 | next = strchrnul(line, ' '); |
392b862e | 219 | replace_cstring(&sigc->fingerprint, line, next); |
4de9394d | 220 | |
67a6ea63 HJI |
221 | /* |
222 | * Skip interim fields. The search is | |
223 | * limited to the same line since only | |
224 | * OpenPGP signatures has a field with | |
225 | * the primary fingerprint. | |
226 | */ | |
227 | limit = strchrnul(line, '\n'); | |
4de9394d | 228 | for (j = 9; j > 0; j--) { |
67a6ea63 | 229 | if (!*next || limit <= next) |
4de9394d MG |
230 | break; |
231 | line = next + 1; | |
232 | next = strchrnul(line, ' '); | |
233 | } | |
234 | ||
67a6ea63 HJI |
235 | field = &sigc->primary_key_fingerprint; |
236 | if (!j) { | |
237 | next = strchrnul(line, '\n'); | |
238 | replace_cstring(field, line, next); | |
239 | } else { | |
240 | replace_cstring(field, NULL, NULL); | |
241 | } | |
3daaaabe | 242 | } |
da6cf1b3 MG |
243 | |
244 | break; | |
661a1806 | 245 | } |
a50e7ca3 JH |
246 | } |
247 | } | |
da6cf1b3 MG |
248 | return; |
249 | ||
54887b46 | 250 | error: |
da6cf1b3 MG |
251 | sigc->result = 'E'; |
252 | /* Clear partial data to avoid confusion */ | |
4de9394d | 253 | FREE_AND_NULL(sigc->primary_key_fingerprint); |
3daaaabe | 254 | FREE_AND_NULL(sigc->fingerprint); |
da6cf1b3 MG |
255 | FREE_AND_NULL(sigc->signer); |
256 | FREE_AND_NULL(sigc->key); | |
a50e7ca3 JH |
257 | } |
258 | ||
434060ec | 259 | int check_signature(const char *payload, size_t plen, const char *signature, |
a4cc18f2 | 260 | size_t slen, struct signature_check *sigc) |
261 | { | |
262 | struct strbuf gpg_output = STRBUF_INIT; | |
263 | struct strbuf gpg_status = STRBUF_INIT; | |
264 | int status; | |
265 | ||
266 | sigc->result = 'N'; | |
54887b46 | 267 | sigc->trust_level = -1; |
a4cc18f2 | 268 | |
269 | status = verify_signed_buffer(payload, plen, signature, slen, | |
270 | &gpg_output, &gpg_status); | |
271 | if (status && !gpg_output.len) | |
272 | goto out; | |
273 | sigc->payload = xmemdupz(payload, plen); | |
274 | sigc->gpg_output = strbuf_detach(&gpg_output, NULL); | |
275 | sigc->gpg_status = strbuf_detach(&gpg_status, NULL); | |
276 | parse_gpg_output(sigc); | |
54887b46 HJI |
277 | status |= sigc->result != 'G'; |
278 | status |= sigc->trust_level < configured_min_trust_level; | |
a4cc18f2 | 279 | |
280 | out: | |
281 | strbuf_release(&gpg_status); | |
282 | strbuf_release(&gpg_output); | |
434060ec | 283 | |
4e5dc9ca | 284 | return !!status; |
a4cc18f2 | 285 | } |
286 | ||
ca194d50 | 287 | void print_signature_buffer(const struct signature_check *sigc, unsigned flags) |
288 | { | |
aeff29dd | 289 | const char *output = flags & GPG_VERIFY_RAW ? |
290 | sigc->gpg_status : sigc->gpg_output; | |
291 | ||
ca194d50 | 292 | if (flags & GPG_VERIFY_VERBOSE && sigc->payload) |
293 | fputs(sigc->payload, stdout); | |
294 | ||
aeff29dd | 295 | if (output) |
296 | fputs(output, stderr); | |
ca194d50 | 297 | } |
298 | ||
e6fa6cde | 299 | size_t parse_signature(const char *buf, size_t size) |
d7c67668 | 300 | { |
d7c67668 | 301 | size_t len = 0; |
8b44b2be JK |
302 | size_t match = size; |
303 | while (len < size) { | |
304 | const char *eol; | |
305 | ||
58af57e1 | 306 | if (get_format_by_sig(buf + len)) |
8b44b2be JK |
307 | match = len; |
308 | ||
309 | eol = memchr(buf + len, '\n', size - len); | |
d7c67668 JH |
310 | len += eol ? eol - (buf + len) + 1 : size - len; |
311 | } | |
8b44b2be | 312 | return match; |
d7c67668 JH |
313 | } |
314 | ||
2f47eae2 JH |
315 | void set_signing_key(const char *key) |
316 | { | |
317 | free(configured_signing_key); | |
318 | configured_signing_key = xstrdup(key); | |
319 | } | |
320 | ||
321 | int git_gpg_config(const char *var, const char *value, void *cb) | |
322 | { | |
58af57e1 HS |
323 | struct gpg_format *fmt = NULL; |
324 | char *fmtname = NULL; | |
54887b46 HJI |
325 | char *trust; |
326 | int ret; | |
58af57e1 | 327 | |
2f47eae2 | 328 | if (!strcmp(var, "user.signingkey")) { |
1b0eeec3 JK |
329 | if (!value) |
330 | return config_error_nonbool(var); | |
0c5e70f0 | 331 | set_signing_key(value); |
1b0eeec3 | 332 | return 0; |
0c5e70f0 | 333 | } |
1b0eeec3 | 334 | |
57a8dd75 HS |
335 | if (!strcmp(var, "gpg.format")) { |
336 | if (!value) | |
337 | return config_error_nonbool(var); | |
58af57e1 HS |
338 | fmt = get_format_by_name(value); |
339 | if (!fmt) | |
57a8dd75 HS |
340 | return error("unsupported value for %s: %s", |
341 | var, value); | |
58af57e1 HS |
342 | use_format = fmt; |
343 | return 0; | |
57a8dd75 HS |
344 | } |
345 | ||
54887b46 HJI |
346 | if (!strcmp(var, "gpg.mintrustlevel")) { |
347 | if (!value) | |
348 | return config_error_nonbool(var); | |
349 | ||
350 | trust = xstrdup_toupper(value); | |
351 | ret = parse_gpg_trust_level(trust, &configured_min_trust_level); | |
352 | free(trust); | |
353 | ||
354 | if (ret) | |
355 | return error("unsupported value for %s: %s", var, | |
356 | value); | |
357 | return 0; | |
358 | } | |
359 | ||
b02f51b1 | 360 | if (!strcmp(var, "gpg.program") || !strcmp(var, "gpg.openpgp.program")) |
58af57e1 HS |
361 | fmtname = "openpgp"; |
362 | ||
1e7adb97 HS |
363 | if (!strcmp(var, "gpg.x509.program")) |
364 | fmtname = "x509"; | |
365 | ||
58af57e1 HS |
366 | if (fmtname) { |
367 | fmt = get_format_by_name(fmtname); | |
368 | return git_config_string(&fmt->program, var, value); | |
2f47eae2 | 369 | } |
1b0eeec3 | 370 | |
2f47eae2 JH |
371 | return 0; |
372 | } | |
373 | ||
374 | const char *get_signing_key(void) | |
375 | { | |
376 | if (configured_signing_key) | |
377 | return configured_signing_key; | |
f9bc573f | 378 | return git_committer_info(IDENT_STRICT|IDENT_NO_DATE); |
2f47eae2 JH |
379 | } |
380 | ||
2f47eae2 JH |
381 | int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key) |
382 | { | |
d3180279 | 383 | struct child_process gpg = CHILD_PROCESS_INIT; |
0581b546 | 384 | int ret; |
2f47eae2 | 385 | size_t i, j, bottom; |
efee9553 | 386 | struct strbuf gpg_status = STRBUF_INIT; |
2f47eae2 | 387 | |
aedb5dc3 | 388 | argv_array_pushl(&gpg.args, |
58af57e1 | 389 | use_format->program, |
efee9553 | 390 | "--status-fd=2", |
aedb5dc3 JK |
391 | "-bsau", signing_key, |
392 | NULL); | |
2f47eae2 | 393 | |
0581b546 | 394 | bottom = signature->len; |
2f47eae2 JH |
395 | |
396 | /* | |
397 | * When the username signingkey is bad, program could be terminated | |
398 | * because gpg exits without reading and then write gets SIGPIPE. | |
399 | */ | |
400 | sigchain_push(SIGPIPE, SIG_IGN); | |
0581b546 | 401 | ret = pipe_command(&gpg, buffer->buf, buffer->len, |
efee9553 | 402 | signature, 1024, &gpg_status, 0); |
2f47eae2 JH |
403 | sigchain_pop(SIGPIPE); |
404 | ||
efee9553 MG |
405 | ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED "); |
406 | strbuf_release(&gpg_status); | |
407 | if (ret) | |
2f47eae2 JH |
408 | return error(_("gpg failed to sign the data")); |
409 | ||
410 | /* Strip CR from the line endings, in case we are on Windows. */ | |
411 | for (i = j = bottom; i < signature->len; i++) | |
412 | if (signature->buf[i] != '\r') { | |
413 | if (i != j) | |
414 | signature->buf[j] = signature->buf[i]; | |
415 | j++; | |
416 | } | |
417 | strbuf_setlen(signature, j); | |
418 | ||
419 | return 0; | |
420 | } | |
0106b1d4 JH |
421 | |
422 | int verify_signed_buffer(const char *payload, size_t payload_size, | |
423 | const char *signature, size_t signature_size, | |
424 | struct strbuf *gpg_output, struct strbuf *gpg_status) | |
425 | { | |
426 | struct child_process gpg = CHILD_PROCESS_INIT; | |
427 | struct gpg_format *fmt; | |
428 | struct tempfile *temp; | |
429 | int ret; | |
430 | struct strbuf buf = STRBUF_INIT; | |
431 | ||
432 | temp = mks_tempfile_t(".git_vtag_tmpXXXXXX"); | |
433 | if (!temp) | |
434 | return error_errno(_("could not create temporary file")); | |
435 | if (write_in_full(temp->fd, signature, signature_size) < 0 || | |
436 | close_tempfile_gently(temp) < 0) { | |
437 | error_errno(_("failed writing detached signature to '%s'"), | |
438 | temp->filename.buf); | |
439 | delete_tempfile(&temp); | |
440 | return -1; | |
441 | } | |
442 | ||
443 | fmt = get_format_by_sig(signature); | |
444 | if (!fmt) | |
445 | BUG("bad signature '%s'", signature); | |
446 | ||
447 | argv_array_push(&gpg.args, fmt->program); | |
448 | argv_array_pushv(&gpg.args, fmt->verify_args); | |
449 | argv_array_pushl(&gpg.args, | |
450 | "--status-fd=1", | |
451 | "--verify", temp->filename.buf, "-", | |
452 | NULL); | |
453 | ||
454 | if (!gpg_status) | |
455 | gpg_status = &buf; | |
456 | ||
457 | sigchain_push(SIGPIPE, SIG_IGN); | |
458 | ret = pipe_command(&gpg, payload, payload_size, | |
459 | gpg_status, 0, gpg_output, 0); | |
460 | sigchain_pop(SIGPIPE); | |
461 | ||
462 | delete_tempfile(&temp); | |
463 | ||
464 | ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG "); | |
465 | strbuf_release(&buf); /* no matter it was used or not */ | |
466 | ||
467 | return ret; | |
468 | } |