promisor-remote: skip move_to_tail when no-op
[git/git.git] / gpg-interface.c
CommitLineData
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
9static char *configured_signing_key;
58af57e1
HS
10struct gpg_format {
11 const char *name;
12 const char *program;
13 const char **verify_args;
14 const char **sigs;
15};
16
17static const char *openpgp_verify_args[] = {
18 "--keyid-format=long",
19 NULL
20};
21static const char *openpgp_sigs[] = {
22 "-----BEGIN PGP SIGNATURE-----",
23 "-----BEGIN PGP MESSAGE-----",
24 NULL
25};
26
1e7adb97
HS
27static const char *x509_verify_args[] = {
28 NULL
29};
30static const char *x509_sigs[] = {
31 "-----BEGIN SIGNED MESSAGE-----",
32 NULL
33};
34
58af57e1
HS
35static struct gpg_format gpg_format[] = {
36 { .name = "openpgp", .program = "gpg",
37 .verify_args = openpgp_verify_args,
38 .sigs = openpgp_sigs
39 },
1e7adb97
HS
40 { .name = "x509", .program = "gpgsm",
41 .verify_args = x509_verify_args,
42 .sigs = x509_sigs
43 },
58af57e1
HS
44};
45
46static struct gpg_format *use_format = &gpg_format[0];
2f47eae2 47
58af57e1
HS
48static struct gpg_format *get_format_by_name(const char *str)
49{
50 int i;
51
52 for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
53 if (!strcmp(gpg_format[i].name, str))
54 return gpg_format + i;
55 return NULL;
56}
57
58static struct gpg_format *get_format_by_sig(const char *sig)
59{
60 int i, j;
61
62 for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
63 for (j = 0; gpg_format[i].sigs[j]; j++)
64 if (starts_with(sig, gpg_format[i].sigs[j]))
65 return gpg_format + i;
66 return NULL;
67}
d7c67668 68
01e57b5d
MG
69void signature_check_clear(struct signature_check *sigc)
70{
88ce3ef6
ÆAB
71 FREE_AND_NULL(sigc->payload);
72 FREE_AND_NULL(sigc->gpg_output);
73 FREE_AND_NULL(sigc->gpg_status);
74 FREE_AND_NULL(sigc->signer);
75 FREE_AND_NULL(sigc->key);
3daaaabe 76 FREE_AND_NULL(sigc->fingerprint);
4de9394d 77 FREE_AND_NULL(sigc->primary_key_fingerprint);
01e57b5d
MG
78}
79
da6cf1b3
MG
80/* An exclusive status -- only one of them can appear in output */
81#define GPG_STATUS_EXCLUSIVE (1<<0)
0b11a84e
MG
82/* The status includes key identifier */
83#define GPG_STATUS_KEYID (1<<1)
84/* The status includes user identifier */
85#define GPG_STATUS_UID (1<<2)
3daaaabe
MG
86/* The status includes key fingerprints */
87#define GPG_STATUS_FINGERPRINT (1<<3)
0b11a84e
MG
88
89/* Short-hand for standard exclusive *SIG status with keyid & UID */
90#define GPG_STATUS_STDSIG (GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID|GPG_STATUS_UID)
da6cf1b3 91
a50e7ca3
JH
92static struct {
93 char result;
94 const char *check;
da6cf1b3 95 unsigned int flags;
a50e7ca3 96} sigcheck_gpg_status[] = {
0b11a84e
MG
97 { 'G', "GOODSIG ", GPG_STATUS_STDSIG },
98 { 'B', "BADSIG ", GPG_STATUS_STDSIG },
da6cf1b3
MG
99 { 'U', "TRUST_NEVER", 0 },
100 { 'U', "TRUST_UNDEFINED", 0 },
0b11a84e
MG
101 { 'E', "ERRSIG ", GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID },
102 { 'X', "EXPSIG ", GPG_STATUS_STDSIG },
103 { 'Y', "EXPKEYSIG ", GPG_STATUS_STDSIG },
104 { 'R', "REVKEYSIG ", GPG_STATUS_STDSIG },
3daaaabe 105 { 0, "VALIDSIG ", GPG_STATUS_FINGERPRINT },
a50e7ca3
JH
106};
107
fbd0f166 108static void parse_gpg_output(struct signature_check *sigc)
a50e7ca3
JH
109{
110 const char *buf = sigc->gpg_status;
da6cf1b3 111 const char *line, *next;
4de9394d 112 int i, j;
da6cf1b3
MG
113 int seen_exclusive_status = 0;
114
115 /* Iterate over all lines */
116 for (line = buf; *line; line = strchrnul(line+1, '\n')) {
117 while (*line == '\n')
118 line++;
119 /* Skip lines that don't start with GNUPG status */
120 if (!skip_prefix(line, "[GNUPG:] ", &line))
121 continue;
122
123 /* Iterate over all search strings */
124 for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
125 if (skip_prefix(line, sigcheck_gpg_status[i].check, &line)) {
126 if (sigcheck_gpg_status[i].flags & GPG_STATUS_EXCLUSIVE) {
02561896 127 if (seen_exclusive_status++)
da6cf1b3
MG
128 goto found_duplicate_status;
129 }
130
3daaaabe
MG
131 if (sigcheck_gpg_status[i].result)
132 sigc->result = sigcheck_gpg_status[i].result;
0b11a84e
MG
133 /* Do we have key information? */
134 if (sigcheck_gpg_status[i].flags & GPG_STATUS_KEYID) {
da6cf1b3
MG
135 next = strchrnul(line, ' ');
136 free(sigc->key);
137 sigc->key = xmemdupz(line, next - line);
0b11a84e
MG
138 /* Do we have signer information? */
139 if (*next && (sigcheck_gpg_status[i].flags & GPG_STATUS_UID)) {
da6cf1b3
MG
140 line = next + 1;
141 next = strchrnul(line, '\n');
142 free(sigc->signer);
143 sigc->signer = xmemdupz(line, next - line);
144 }
145 }
3daaaabe
MG
146 /* Do we have fingerprint? */
147 if (sigcheck_gpg_status[i].flags & GPG_STATUS_FINGERPRINT) {
148 next = strchrnul(line, ' ');
149 free(sigc->fingerprint);
150 sigc->fingerprint = xmemdupz(line, next - line);
4de9394d
MG
151
152 /* Skip interim fields */
153 for (j = 9; j > 0; j--) {
154 if (!*next)
155 break;
156 line = next + 1;
157 next = strchrnul(line, ' ');
158 }
159
160 next = strchrnul(line, '\n');
161 free(sigc->primary_key_fingerprint);
162 sigc->primary_key_fingerprint = xmemdupz(line, next - line);
3daaaabe 163 }
da6cf1b3
MG
164
165 break;
661a1806 166 }
a50e7ca3
JH
167 }
168 }
da6cf1b3
MG
169 return;
170
171found_duplicate_status:
172 /*
173 * GOODSIG, BADSIG etc. can occur only once for each signature.
174 * Therefore, if we had more than one then we're dealing with multiple
175 * signatures. We don't support them currently, and they're rather
176 * hard to create, so something is likely fishy and we should reject
177 * them altogether.
178 */
179 sigc->result = 'E';
180 /* Clear partial data to avoid confusion */
4de9394d 181 FREE_AND_NULL(sigc->primary_key_fingerprint);
3daaaabe 182 FREE_AND_NULL(sigc->fingerprint);
da6cf1b3
MG
183 FREE_AND_NULL(sigc->signer);
184 FREE_AND_NULL(sigc->key);
a50e7ca3
JH
185}
186
434060ec 187int check_signature(const char *payload, size_t plen, const char *signature,
a4cc18f2 188 size_t slen, struct signature_check *sigc)
189{
190 struct strbuf gpg_output = STRBUF_INIT;
191 struct strbuf gpg_status = STRBUF_INIT;
192 int status;
193
194 sigc->result = 'N';
195
196 status = verify_signed_buffer(payload, plen, signature, slen,
197 &gpg_output, &gpg_status);
198 if (status && !gpg_output.len)
199 goto out;
200 sigc->payload = xmemdupz(payload, plen);
201 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
202 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
203 parse_gpg_output(sigc);
4e5dc9ca 204 status |= sigc->result != 'G' && sigc->result != 'U';
a4cc18f2 205
206 out:
207 strbuf_release(&gpg_status);
208 strbuf_release(&gpg_output);
434060ec 209
4e5dc9ca 210 return !!status;
a4cc18f2 211}
212
ca194d50 213void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
214{
aeff29dd 215 const char *output = flags & GPG_VERIFY_RAW ?
216 sigc->gpg_status : sigc->gpg_output;
217
ca194d50 218 if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
219 fputs(sigc->payload, stdout);
220
aeff29dd 221 if (output)
222 fputs(output, stderr);
ca194d50 223}
224
e6fa6cde 225size_t parse_signature(const char *buf, size_t size)
d7c67668 226{
d7c67668 227 size_t len = 0;
8b44b2be
JK
228 size_t match = size;
229 while (len < size) {
230 const char *eol;
231
58af57e1 232 if (get_format_by_sig(buf + len))
8b44b2be
JK
233 match = len;
234
235 eol = memchr(buf + len, '\n', size - len);
d7c67668
JH
236 len += eol ? eol - (buf + len) + 1 : size - len;
237 }
8b44b2be 238 return match;
d7c67668
JH
239}
240
2f47eae2
JH
241void set_signing_key(const char *key)
242{
243 free(configured_signing_key);
244 configured_signing_key = xstrdup(key);
245}
246
247int git_gpg_config(const char *var, const char *value, void *cb)
248{
58af57e1
HS
249 struct gpg_format *fmt = NULL;
250 char *fmtname = NULL;
251
2f47eae2 252 if (!strcmp(var, "user.signingkey")) {
1b0eeec3
JK
253 if (!value)
254 return config_error_nonbool(var);
0c5e70f0 255 set_signing_key(value);
1b0eeec3 256 return 0;
0c5e70f0 257 }
1b0eeec3 258
57a8dd75
HS
259 if (!strcmp(var, "gpg.format")) {
260 if (!value)
261 return config_error_nonbool(var);
58af57e1
HS
262 fmt = get_format_by_name(value);
263 if (!fmt)
57a8dd75
HS
264 return error("unsupported value for %s: %s",
265 var, value);
58af57e1
HS
266 use_format = fmt;
267 return 0;
57a8dd75
HS
268 }
269
b02f51b1 270 if (!strcmp(var, "gpg.program") || !strcmp(var, "gpg.openpgp.program"))
58af57e1
HS
271 fmtname = "openpgp";
272
1e7adb97
HS
273 if (!strcmp(var, "gpg.x509.program"))
274 fmtname = "x509";
275
58af57e1
HS
276 if (fmtname) {
277 fmt = get_format_by_name(fmtname);
278 return git_config_string(&fmt->program, var, value);
2f47eae2 279 }
1b0eeec3 280
2f47eae2
JH
281 return 0;
282}
283
284const char *get_signing_key(void)
285{
286 if (configured_signing_key)
287 return configured_signing_key;
f9bc573f 288 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
2f47eae2
JH
289}
290
2f47eae2
JH
291int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
292{
d3180279 293 struct child_process gpg = CHILD_PROCESS_INIT;
0581b546 294 int ret;
2f47eae2 295 size_t i, j, bottom;
efee9553 296 struct strbuf gpg_status = STRBUF_INIT;
2f47eae2 297
aedb5dc3 298 argv_array_pushl(&gpg.args,
58af57e1 299 use_format->program,
efee9553 300 "--status-fd=2",
aedb5dc3
JK
301 "-bsau", signing_key,
302 NULL);
2f47eae2 303
0581b546 304 bottom = signature->len;
2f47eae2
JH
305
306 /*
307 * When the username signingkey is bad, program could be terminated
308 * because gpg exits without reading and then write gets SIGPIPE.
309 */
310 sigchain_push(SIGPIPE, SIG_IGN);
0581b546 311 ret = pipe_command(&gpg, buffer->buf, buffer->len,
efee9553 312 signature, 1024, &gpg_status, 0);
2f47eae2
JH
313 sigchain_pop(SIGPIPE);
314
efee9553
MG
315 ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED ");
316 strbuf_release(&gpg_status);
317 if (ret)
2f47eae2
JH
318 return error(_("gpg failed to sign the data"));
319
320 /* Strip CR from the line endings, in case we are on Windows. */
321 for (i = j = bottom; i < signature->len; i++)
322 if (signature->buf[i] != '\r') {
323 if (i != j)
324 signature->buf[j] = signature->buf[i];
325 j++;
326 }
327 strbuf_setlen(signature, j);
328
329 return 0;
330}
331
2f47eae2
JH
332int verify_signed_buffer(const char *payload, size_t payload_size,
333 const char *signature, size_t signature_size,
9cc4ac8f 334 struct strbuf *gpg_output, struct strbuf *gpg_status)
2f47eae2 335{
d3180279 336 struct child_process gpg = CHILD_PROCESS_INIT;
58af57e1 337 struct gpg_format *fmt;
076aa2cb
JK
338 struct tempfile *temp;
339 int ret;
b60b7566 340 struct strbuf buf = STRBUF_INIT;
2f47eae2 341
076aa2cb
JK
342 temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
343 if (!temp)
4322353b 344 return error_errno(_("could not create temporary file"));
076aa2cb
JK
345 if (write_in_full(temp->fd, signature, signature_size) < 0 ||
346 close_tempfile_gently(temp) < 0) {
4322353b 347 error_errno(_("failed writing detached signature to '%s'"),
076aa2cb 348 temp->filename.buf);
4322353b
JK
349 delete_tempfile(&temp);
350 return -1;
351 }
2f47eae2 352
58af57e1
HS
353 fmt = get_format_by_sig(signature);
354 if (!fmt)
355 BUG("bad signature '%s'", signature);
356
357 argv_array_push(&gpg.args, fmt->program);
358 argv_array_pushv(&gpg.args, fmt->verify_args);
aedb5dc3 359 argv_array_pushl(&gpg.args,
aedb5dc3 360 "--status-fd=1",
076aa2cb 361 "--verify", temp->filename.buf, "-",
aedb5dc3 362 NULL);
2f47eae2 363
c752fcc8
JK
364 if (!gpg_status)
365 gpg_status = &buf;
b60b7566 366
0d2b664e
JK
367 sigchain_push(SIGPIPE, SIG_IGN);
368 ret = pipe_command(&gpg, payload, payload_size,
369 gpg_status, 0, gpg_output, 0);
d281b45d 370 sigchain_pop(SIGPIPE);
2f47eae2 371
4322353b 372 delete_tempfile(&temp);
2f47eae2 373
c752fcc8 374 ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
9cc4ac8f 375 strbuf_release(&buf); /* no matter it was used or not */
b60b7566 376
2f47eae2
JH
377 return ret;
378}