Git 2.19.1
[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);
01e57b5d
MG
76}
77
a50e7ca3
JH
78static struct {
79 char result;
80 const char *check;
81} sigcheck_gpg_status[] = {
82 { 'G', "\n[GNUPG:] GOODSIG " },
83 { 'B', "\n[GNUPG:] BADSIG " },
84 { 'U', "\n[GNUPG:] TRUST_NEVER" },
85 { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
661a1806
MG
86 { 'E', "\n[GNUPG:] ERRSIG "},
87 { 'X', "\n[GNUPG:] EXPSIG "},
88 { 'Y', "\n[GNUPG:] EXPKEYSIG "},
89 { 'R', "\n[GNUPG:] REVKEYSIG "},
a50e7ca3
JH
90};
91
fbd0f166 92static void parse_gpg_output(struct signature_check *sigc)
a50e7ca3
JH
93{
94 const char *buf = sigc->gpg_status;
95 int i;
96
97 /* Iterate over all search strings */
98 for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
99 const char *found, *next;
100
101 if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
102 found = strstr(buf, sigcheck_gpg_status[i].check);
103 if (!found)
104 continue;
105 found += strlen(sigcheck_gpg_status[i].check);
106 }
107 sigc->result = sigcheck_gpg_status[i].result;
108 /* The trust messages are not followed by key/signer information */
109 if (sigc->result != 'U') {
42149d7f
HS
110 next = strchrnul(found, ' ');
111 sigc->key = xmemdupz(found, next - found);
661a1806 112 /* The ERRSIG message is not followed by signer information */
42149d7f
HS
113 if (*next && sigc-> result != 'E') {
114 found = next + 1;
661a1806
MG
115 next = strchrnul(found, '\n');
116 sigc->signer = xmemdupz(found, next - found);
117 }
a50e7ca3
JH
118 }
119 }
120}
121
434060ec 122int check_signature(const char *payload, size_t plen, const char *signature,
a4cc18f2 123 size_t slen, struct signature_check *sigc)
124{
125 struct strbuf gpg_output = STRBUF_INIT;
126 struct strbuf gpg_status = STRBUF_INIT;
127 int status;
128
129 sigc->result = 'N';
130
131 status = verify_signed_buffer(payload, plen, signature, slen,
132 &gpg_output, &gpg_status);
133 if (status && !gpg_output.len)
134 goto out;
135 sigc->payload = xmemdupz(payload, plen);
136 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
137 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
138 parse_gpg_output(sigc);
4e5dc9ca 139 status |= sigc->result != 'G' && sigc->result != 'U';
a4cc18f2 140
141 out:
142 strbuf_release(&gpg_status);
143 strbuf_release(&gpg_output);
434060ec 144
4e5dc9ca 145 return !!status;
a4cc18f2 146}
147
ca194d50 148void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
149{
aeff29dd 150 const char *output = flags & GPG_VERIFY_RAW ?
151 sigc->gpg_status : sigc->gpg_output;
152
ca194d50 153 if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
154 fputs(sigc->payload, stdout);
155
aeff29dd 156 if (output)
157 fputs(output, stderr);
ca194d50 158}
159
e6fa6cde 160size_t parse_signature(const char *buf, size_t size)
d7c67668 161{
d7c67668 162 size_t len = 0;
8b44b2be
JK
163 size_t match = size;
164 while (len < size) {
165 const char *eol;
166
58af57e1 167 if (get_format_by_sig(buf + len))
8b44b2be
JK
168 match = len;
169
170 eol = memchr(buf + len, '\n', size - len);
d7c67668
JH
171 len += eol ? eol - (buf + len) + 1 : size - len;
172 }
8b44b2be 173 return match;
d7c67668
JH
174}
175
2f47eae2
JH
176void set_signing_key(const char *key)
177{
178 free(configured_signing_key);
179 configured_signing_key = xstrdup(key);
180}
181
182int git_gpg_config(const char *var, const char *value, void *cb)
183{
58af57e1
HS
184 struct gpg_format *fmt = NULL;
185 char *fmtname = NULL;
186
2f47eae2 187 if (!strcmp(var, "user.signingkey")) {
1b0eeec3
JK
188 if (!value)
189 return config_error_nonbool(var);
0c5e70f0 190 set_signing_key(value);
1b0eeec3 191 return 0;
0c5e70f0 192 }
1b0eeec3 193
57a8dd75
HS
194 if (!strcmp(var, "gpg.format")) {
195 if (!value)
196 return config_error_nonbool(var);
58af57e1
HS
197 fmt = get_format_by_name(value);
198 if (!fmt)
57a8dd75
HS
199 return error("unsupported value for %s: %s",
200 var, value);
58af57e1
HS
201 use_format = fmt;
202 return 0;
57a8dd75
HS
203 }
204
b02f51b1 205 if (!strcmp(var, "gpg.program") || !strcmp(var, "gpg.openpgp.program"))
58af57e1
HS
206 fmtname = "openpgp";
207
1e7adb97
HS
208 if (!strcmp(var, "gpg.x509.program"))
209 fmtname = "x509";
210
58af57e1
HS
211 if (fmtname) {
212 fmt = get_format_by_name(fmtname);
213 return git_config_string(&fmt->program, var, value);
2f47eae2 214 }
1b0eeec3 215
2f47eae2
JH
216 return 0;
217}
218
219const char *get_signing_key(void)
220{
221 if (configured_signing_key)
222 return configured_signing_key;
f9bc573f 223 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
2f47eae2
JH
224}
225
2f47eae2
JH
226int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
227{
d3180279 228 struct child_process gpg = CHILD_PROCESS_INIT;
0581b546 229 int ret;
2f47eae2 230 size_t i, j, bottom;
efee9553 231 struct strbuf gpg_status = STRBUF_INIT;
2f47eae2 232
aedb5dc3 233 argv_array_pushl(&gpg.args,
58af57e1 234 use_format->program,
efee9553 235 "--status-fd=2",
aedb5dc3
JK
236 "-bsau", signing_key,
237 NULL);
2f47eae2 238
0581b546 239 bottom = signature->len;
2f47eae2
JH
240
241 /*
242 * When the username signingkey is bad, program could be terminated
243 * because gpg exits without reading and then write gets SIGPIPE.
244 */
245 sigchain_push(SIGPIPE, SIG_IGN);
0581b546 246 ret = pipe_command(&gpg, buffer->buf, buffer->len,
efee9553 247 signature, 1024, &gpg_status, 0);
2f47eae2
JH
248 sigchain_pop(SIGPIPE);
249
efee9553
MG
250 ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED ");
251 strbuf_release(&gpg_status);
252 if (ret)
2f47eae2
JH
253 return error(_("gpg failed to sign the data"));
254
255 /* Strip CR from the line endings, in case we are on Windows. */
256 for (i = j = bottom; i < signature->len; i++)
257 if (signature->buf[i] != '\r') {
258 if (i != j)
259 signature->buf[j] = signature->buf[i];
260 j++;
261 }
262 strbuf_setlen(signature, j);
263
264 return 0;
265}
266
2f47eae2
JH
267int verify_signed_buffer(const char *payload, size_t payload_size,
268 const char *signature, size_t signature_size,
9cc4ac8f 269 struct strbuf *gpg_output, struct strbuf *gpg_status)
2f47eae2 270{
d3180279 271 struct child_process gpg = CHILD_PROCESS_INIT;
58af57e1 272 struct gpg_format *fmt;
076aa2cb
JK
273 struct tempfile *temp;
274 int ret;
b60b7566 275 struct strbuf buf = STRBUF_INIT;
2f47eae2 276
076aa2cb
JK
277 temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
278 if (!temp)
4322353b 279 return error_errno(_("could not create temporary file"));
076aa2cb
JK
280 if (write_in_full(temp->fd, signature, signature_size) < 0 ||
281 close_tempfile_gently(temp) < 0) {
4322353b 282 error_errno(_("failed writing detached signature to '%s'"),
076aa2cb 283 temp->filename.buf);
4322353b
JK
284 delete_tempfile(&temp);
285 return -1;
286 }
2f47eae2 287
58af57e1
HS
288 fmt = get_format_by_sig(signature);
289 if (!fmt)
290 BUG("bad signature '%s'", signature);
291
292 argv_array_push(&gpg.args, fmt->program);
293 argv_array_pushv(&gpg.args, fmt->verify_args);
aedb5dc3 294 argv_array_pushl(&gpg.args,
aedb5dc3 295 "--status-fd=1",
076aa2cb 296 "--verify", temp->filename.buf, "-",
aedb5dc3 297 NULL);
2f47eae2 298
c752fcc8
JK
299 if (!gpg_status)
300 gpg_status = &buf;
b60b7566 301
0d2b664e
JK
302 sigchain_push(SIGPIPE, SIG_IGN);
303 ret = pipe_command(&gpg, payload, payload_size,
304 gpg_status, 0, gpg_output, 0);
d281b45d 305 sigchain_pop(SIGPIPE);
2f47eae2 306
4322353b 307 delete_tempfile(&temp);
2f47eae2 308
c752fcc8 309 ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
9cc4ac8f 310 strbuf_release(&buf); /* no matter it was used or not */
b60b7566 311
2f47eae2
JH
312 return ret;
313}