coccinelle: make use of the "expression" FREE_AND_NULL() rule
[git/git.git] / gpg-interface.c
CommitLineData
2f47eae2
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1#include "cache.h"
2#include "run-command.h"
3#include "strbuf.h"
4#include "gpg-interface.h"
5#include "sigchain.h"
4322353b 6#include "tempfile.h"
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7
8static char *configured_signing_key;
0c5e70f0 9static const char *gpg_program = "gpg";
2f47eae2 10
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11#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
12#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
13
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14void signature_check_clear(struct signature_check *sigc)
15{
71c214c8 16 free(sigc->payload);
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17 free(sigc->gpg_output);
18 free(sigc->gpg_status);
19 free(sigc->signer);
20 free(sigc->key);
71c214c8 21 sigc->payload = NULL;
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22 sigc->gpg_output = NULL;
23 sigc->gpg_status = NULL;
24 sigc->signer = NULL;
25 sigc->key = NULL;
26}
27
a50e7ca3
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28static struct {
29 char result;
30 const char *check;
31} sigcheck_gpg_status[] = {
32 { 'G', "\n[GNUPG:] GOODSIG " },
33 { 'B', "\n[GNUPG:] BADSIG " },
34 { 'U', "\n[GNUPG:] TRUST_NEVER" },
35 { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
661a1806
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36 { 'E', "\n[GNUPG:] ERRSIG "},
37 { 'X', "\n[GNUPG:] EXPSIG "},
38 { 'Y', "\n[GNUPG:] EXPKEYSIG "},
39 { 'R', "\n[GNUPG:] REVKEYSIG "},
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40};
41
42void parse_gpg_output(struct signature_check *sigc)
43{
44 const char *buf = sigc->gpg_status;
45 int i;
46
47 /* Iterate over all search strings */
48 for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
49 const char *found, *next;
50
51 if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
52 found = strstr(buf, sigcheck_gpg_status[i].check);
53 if (!found)
54 continue;
55 found += strlen(sigcheck_gpg_status[i].check);
56 }
57 sigc->result = sigcheck_gpg_status[i].result;
58 /* The trust messages are not followed by key/signer information */
59 if (sigc->result != 'U') {
60 sigc->key = xmemdupz(found, 16);
661a1806
MG
61 /* The ERRSIG message is not followed by signer information */
62 if (sigc-> result != 'E') {
63 found += 17;
64 next = strchrnul(found, '\n');
65 sigc->signer = xmemdupz(found, next - found);
66 }
a50e7ca3
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67 }
68 }
69}
70
434060ec 71int check_signature(const char *payload, size_t plen, const char *signature,
a4cc18f2 72 size_t slen, struct signature_check *sigc)
73{
74 struct strbuf gpg_output = STRBUF_INIT;
75 struct strbuf gpg_status = STRBUF_INIT;
76 int status;
77
78 sigc->result = 'N';
79
80 status = verify_signed_buffer(payload, plen, signature, slen,
81 &gpg_output, &gpg_status);
82 if (status && !gpg_output.len)
83 goto out;
84 sigc->payload = xmemdupz(payload, plen);
85 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
86 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
87 parse_gpg_output(sigc);
88
89 out:
90 strbuf_release(&gpg_status);
91 strbuf_release(&gpg_output);
434060ec 92
93 return sigc->result != 'G' && sigc->result != 'U';
a4cc18f2 94}
95
ca194d50 96void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
97{
aeff29dd 98 const char *output = flags & GPG_VERIFY_RAW ?
99 sigc->gpg_status : sigc->gpg_output;
100
ca194d50 101 if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
102 fputs(sigc->payload, stdout);
103
aeff29dd 104 if (output)
105 fputs(output, stderr);
ca194d50 106}
107
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108/*
109 * Look at GPG signed content (e.g. a signed tag object), whose
110 * payload is followed by a detached signature on it. Return the
111 * offset where the embedded detached signature begins, or the end of
112 * the data when there is no such signature.
113 */
114size_t parse_signature(const char *buf, unsigned long size)
115{
116 char *eol;
117 size_t len = 0;
118 while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
119 !starts_with(buf + len, PGP_MESSAGE)) {
120 eol = memchr(buf + len, '\n', size - len);
121 len += eol ? eol - (buf + len) + 1 : size - len;
122 }
123 return len;
124}
125
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126void set_signing_key(const char *key)
127{
128 free(configured_signing_key);
129 configured_signing_key = xstrdup(key);
130}
131
132int git_gpg_config(const char *var, const char *value, void *cb)
133{
134 if (!strcmp(var, "user.signingkey")) {
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135 set_signing_key(value);
136 }
137 if (!strcmp(var, "gpg.program")) {
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138 if (!value)
139 return config_error_nonbool(var);
0c5e70f0 140 gpg_program = xstrdup(value);
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141 }
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
152/*
153 * Create a detached signature for the contents of "buffer" and append
154 * it after "signature"; "buffer" and "signature" can be the same
155 * strbuf instance, which would cause the detached signature appended
156 * at the end.
157 */
158int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
159{
d3180279 160 struct child_process gpg = CHILD_PROCESS_INIT;
0581b546 161 int ret;
2f47eae2 162 size_t i, j, bottom;
efee9553 163 struct strbuf gpg_status = STRBUF_INIT;
2f47eae2 164
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165 argv_array_pushl(&gpg.args,
166 gpg_program,
efee9553 167 "--status-fd=2",
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168 "-bsau", signing_key,
169 NULL);
2f47eae2 170
0581b546 171 bottom = signature->len;
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172
173 /*
174 * When the username signingkey is bad, program could be terminated
175 * because gpg exits without reading and then write gets SIGPIPE.
176 */
177 sigchain_push(SIGPIPE, SIG_IGN);
0581b546 178 ret = pipe_command(&gpg, buffer->buf, buffer->len,
efee9553 179 signature, 1024, &gpg_status, 0);
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180 sigchain_pop(SIGPIPE);
181
efee9553
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182 ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED ");
183 strbuf_release(&gpg_status);
184 if (ret)
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185 return error(_("gpg failed to sign the data"));
186
187 /* Strip CR from the line endings, in case we are on Windows. */
188 for (i = j = bottom; i < signature->len; i++)
189 if (signature->buf[i] != '\r') {
190 if (i != j)
191 signature->buf[j] = signature->buf[i];
192 j++;
193 }
194 strbuf_setlen(signature, j);
195
196 return 0;
197}
198
199/*
200 * Run "gpg" to see if the payload matches the detached signature.
e3f55e07 201 * gpg_output, when set, receives the diagnostic output from GPG.
b60b7566 202 * gpg_status, when set, receives the status output from GPG.
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203 */
204int verify_signed_buffer(const char *payload, size_t payload_size,
205 const char *signature, size_t signature_size,
9cc4ac8f 206 struct strbuf *gpg_output, struct strbuf *gpg_status)
2f47eae2 207{
d3180279 208 struct child_process gpg = CHILD_PROCESS_INIT;
4322353b 209 static struct tempfile temp;
2f47eae2 210 int fd, ret;
b60b7566 211 struct strbuf buf = STRBUF_INIT;
2f47eae2 212
4322353b 213 fd = mks_tempfile_t(&temp, ".git_vtag_tmpXXXXXX");
2f47eae2 214 if (fd < 0)
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215 return error_errno(_("could not create temporary file"));
216 if (write_in_full(fd, signature, signature_size) < 0) {
217 error_errno(_("failed writing detached signature to '%s'"),
218 temp.filename.buf);
219 delete_tempfile(&temp);
220 return -1;
221 }
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222 close(fd);
223
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224 argv_array_pushl(&gpg.args,
225 gpg_program,
226 "--status-fd=1",
af2b21ec 227 "--keyid-format=long",
4322353b 228 "--verify", temp.filename.buf, "-",
aedb5dc3 229 NULL);
2f47eae2 230
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231 if (!gpg_status)
232 gpg_status = &buf;
b60b7566 233
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234 sigchain_push(SIGPIPE, SIG_IGN);
235 ret = pipe_command(&gpg, payload, payload_size,
236 gpg_status, 0, gpg_output, 0);
d281b45d 237 sigchain_pop(SIGPIPE);
2f47eae2 238
4322353b 239 delete_tempfile(&temp);
2f47eae2 240
c752fcc8 241 ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
9cc4ac8f 242 strbuf_release(&buf); /* no matter it was used or not */
b60b7566 243
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244 return ret;
245}