gpg-interface: extract gpg line matching helper
[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"
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8
9static char *configured_signing_key;
0c5e70f0 10static const char *gpg_program = "gpg";
2f47eae2 11
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12#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
13#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
14
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MG
15void signature_check_clear(struct signature_check *sigc)
16{
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17 FREE_AND_NULL(sigc->payload);
18 FREE_AND_NULL(sigc->gpg_output);
19 FREE_AND_NULL(sigc->gpg_status);
20 FREE_AND_NULL(sigc->signer);
21 FREE_AND_NULL(sigc->key);
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22}
23
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24static struct {
25 char result;
26 const char *check;
27} sigcheck_gpg_status[] = {
28 { 'G', "\n[GNUPG:] GOODSIG " },
29 { 'B', "\n[GNUPG:] BADSIG " },
30 { 'U', "\n[GNUPG:] TRUST_NEVER" },
31 { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
661a1806
MG
32 { 'E', "\n[GNUPG:] ERRSIG "},
33 { 'X', "\n[GNUPG:] EXPSIG "},
34 { 'Y', "\n[GNUPG:] EXPKEYSIG "},
35 { 'R', "\n[GNUPG:] REVKEYSIG "},
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36};
37
38void parse_gpg_output(struct signature_check *sigc)
39{
40 const char *buf = sigc->gpg_status;
41 int i;
42
43 /* Iterate over all search strings */
44 for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
45 const char *found, *next;
46
47 if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
48 found = strstr(buf, sigcheck_gpg_status[i].check);
49 if (!found)
50 continue;
51 found += strlen(sigcheck_gpg_status[i].check);
52 }
53 sigc->result = sigcheck_gpg_status[i].result;
54 /* The trust messages are not followed by key/signer information */
55 if (sigc->result != 'U') {
56 sigc->key = xmemdupz(found, 16);
661a1806
MG
57 /* The ERRSIG message is not followed by signer information */
58 if (sigc-> result != 'E') {
59 found += 17;
60 next = strchrnul(found, '\n');
61 sigc->signer = xmemdupz(found, next - found);
62 }
a50e7ca3
JH
63 }
64 }
65}
66
434060ec 67int check_signature(const char *payload, size_t plen, const char *signature,
a4cc18f2 68 size_t slen, struct signature_check *sigc)
69{
70 struct strbuf gpg_output = STRBUF_INIT;
71 struct strbuf gpg_status = STRBUF_INIT;
72 int status;
73
74 sigc->result = 'N';
75
76 status = verify_signed_buffer(payload, plen, signature, slen,
77 &gpg_output, &gpg_status);
78 if (status && !gpg_output.len)
79 goto out;
80 sigc->payload = xmemdupz(payload, plen);
81 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
82 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
83 parse_gpg_output(sigc);
84
85 out:
86 strbuf_release(&gpg_status);
87 strbuf_release(&gpg_output);
434060ec 88
89 return sigc->result != 'G' && sigc->result != 'U';
a4cc18f2 90}
91
ca194d50 92void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
93{
aeff29dd 94 const char *output = flags & GPG_VERIFY_RAW ?
95 sigc->gpg_status : sigc->gpg_output;
96
ca194d50 97 if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
98 fputs(sigc->payload, stdout);
99
aeff29dd 100 if (output)
101 fputs(output, stderr);
ca194d50 102}
103
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JK
104static int is_gpg_start(const char *line)
105{
106 return starts_with(line, PGP_SIGNATURE) ||
107 starts_with(line, PGP_MESSAGE);
108}
109
e6fa6cde 110size_t parse_signature(const char *buf, size_t size)
d7c67668 111{
d7c67668 112 size_t len = 0;
f68f2dd5 113 while (len < size && !is_gpg_start(buf + len)) {
17ef3a42 114 const char *eol = memchr(buf + len, '\n', size - len);
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115 len += eol ? eol - (buf + len) + 1 : size - len;
116 }
117 return len;
118}
119
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120void set_signing_key(const char *key)
121{
122 free(configured_signing_key);
123 configured_signing_key = xstrdup(key);
124}
125
126int git_gpg_config(const char *var, const char *value, void *cb)
127{
128 if (!strcmp(var, "user.signingkey")) {
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129 if (!value)
130 return config_error_nonbool(var);
0c5e70f0 131 set_signing_key(value);
1b0eeec3 132 return 0;
0c5e70f0 133 }
1b0eeec3 134
0c5e70f0 135 if (!strcmp(var, "gpg.program")) {
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136 if (!value)
137 return config_error_nonbool(var);
0c5e70f0 138 gpg_program = xstrdup(value);
1b0eeec3 139 return 0;
2f47eae2 140 }
1b0eeec3 141
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142 return 0;
143}
144
145const char *get_signing_key(void)
146{
147 if (configured_signing_key)
148 return configured_signing_key;
f9bc573f 149 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
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150}
151
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152int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
153{
d3180279 154 struct child_process gpg = CHILD_PROCESS_INIT;
0581b546 155 int ret;
2f47eae2 156 size_t i, j, bottom;
efee9553 157 struct strbuf gpg_status = STRBUF_INIT;
2f47eae2 158
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159 argv_array_pushl(&gpg.args,
160 gpg_program,
efee9553 161 "--status-fd=2",
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162 "-bsau", signing_key,
163 NULL);
2f47eae2 164
0581b546 165 bottom = signature->len;
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166
167 /*
168 * When the username signingkey is bad, program could be terminated
169 * because gpg exits without reading and then write gets SIGPIPE.
170 */
171 sigchain_push(SIGPIPE, SIG_IGN);
0581b546 172 ret = pipe_command(&gpg, buffer->buf, buffer->len,
efee9553 173 signature, 1024, &gpg_status, 0);
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174 sigchain_pop(SIGPIPE);
175
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176 ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED ");
177 strbuf_release(&gpg_status);
178 if (ret)
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179 return error(_("gpg failed to sign the data"));
180
181 /* Strip CR from the line endings, in case we are on Windows. */
182 for (i = j = bottom; i < signature->len; i++)
183 if (signature->buf[i] != '\r') {
184 if (i != j)
185 signature->buf[j] = signature->buf[i];
186 j++;
187 }
188 strbuf_setlen(signature, j);
189
190 return 0;
191}
192
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193int verify_signed_buffer(const char *payload, size_t payload_size,
194 const char *signature, size_t signature_size,
9cc4ac8f 195 struct strbuf *gpg_output, struct strbuf *gpg_status)
2f47eae2 196{
d3180279 197 struct child_process gpg = CHILD_PROCESS_INIT;
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198 struct tempfile *temp;
199 int ret;
b60b7566 200 struct strbuf buf = STRBUF_INIT;
2f47eae2 201
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202 temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
203 if (!temp)
4322353b 204 return error_errno(_("could not create temporary file"));
076aa2cb
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205 if (write_in_full(temp->fd, signature, signature_size) < 0 ||
206 close_tempfile_gently(temp) < 0) {
4322353b 207 error_errno(_("failed writing detached signature to '%s'"),
076aa2cb 208 temp->filename.buf);
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209 delete_tempfile(&temp);
210 return -1;
211 }
2f47eae2 212
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213 argv_array_pushl(&gpg.args,
214 gpg_program,
215 "--status-fd=1",
af2b21ec 216 "--keyid-format=long",
076aa2cb 217 "--verify", temp->filename.buf, "-",
aedb5dc3 218 NULL);
2f47eae2 219
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220 if (!gpg_status)
221 gpg_status = &buf;
b60b7566 222
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223 sigchain_push(SIGPIPE, SIG_IGN);
224 ret = pipe_command(&gpg, payload, payload_size,
225 gpg_status, 0, gpg_output, 0);
d281b45d 226 sigchain_pop(SIGPIPE);
2f47eae2 227
4322353b 228 delete_tempfile(&temp);
2f47eae2 229
c752fcc8 230 ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
9cc4ac8f 231 strbuf_release(&buf); /* no matter it was used or not */
b60b7566 232
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233 return ret;
234}