git-multimail: update to release 1.2.0
[git.git] / gpg-interface.c
blob3dc2fe397e32d79713780596f0ef4666c14b5955
1 #include "cache.h"
2 #include "run-command.h"
3 #include "strbuf.h"
4 #include "gpg-interface.h"
5 #include "sigchain.h"
7 static char *configured_signing_key;
8 static const char *gpg_program = "gpg";
10 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
11 #define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
13 void signature_check_clear(struct signature_check *sigc)
15 free(sigc->payload);
16 free(sigc->gpg_output);
17 free(sigc->gpg_status);
18 free(sigc->signer);
19 free(sigc->key);
20 sigc->payload = NULL;
21 sigc->gpg_output = NULL;
22 sigc->gpg_status = NULL;
23 sigc->signer = NULL;
24 sigc->key = NULL;
27 static struct {
28 char result;
29 const char *check;
30 } sigcheck_gpg_status[] = {
31 { 'G', "\n[GNUPG:] GOODSIG " },
32 { 'B', "\n[GNUPG:] BADSIG " },
33 { 'U', "\n[GNUPG:] TRUST_NEVER" },
34 { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
37 void parse_gpg_output(struct signature_check *sigc)
39 const char *buf = sigc->gpg_status;
40 int i;
42 /* Iterate over all search strings */
43 for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
44 const char *found, *next;
46 if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
47 found = strstr(buf, sigcheck_gpg_status[i].check);
48 if (!found)
49 continue;
50 found += strlen(sigcheck_gpg_status[i].check);
52 sigc->result = sigcheck_gpg_status[i].result;
53 /* The trust messages are not followed by key/signer information */
54 if (sigc->result != 'U') {
55 sigc->key = xmemdupz(found, 16);
56 found += 17;
57 next = strchrnul(found, '\n');
58 sigc->signer = xmemdupz(found, next - found);
63 int check_signature(const char *payload, size_t plen, const char *signature,
64 size_t slen, struct signature_check *sigc)
66 struct strbuf gpg_output = STRBUF_INIT;
67 struct strbuf gpg_status = STRBUF_INIT;
68 int status;
70 sigc->result = 'N';
72 status = verify_signed_buffer(payload, plen, signature, slen,
73 &gpg_output, &gpg_status);
74 if (status && !gpg_output.len)
75 goto out;
76 sigc->payload = xmemdupz(payload, plen);
77 sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
78 sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
79 parse_gpg_output(sigc);
81 out:
82 strbuf_release(&gpg_status);
83 strbuf_release(&gpg_output);
85 return sigc->result != 'G' && sigc->result != 'U';
88 void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
90 const char *output = flags & GPG_VERIFY_RAW ?
91 sigc->gpg_status : sigc->gpg_output;
93 if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
94 fputs(sigc->payload, stdout);
96 if (output)
97 fputs(output, stderr);
101 * Look at GPG signed content (e.g. a signed tag object), whose
102 * payload is followed by a detached signature on it. Return the
103 * offset where the embedded detached signature begins, or the end of
104 * the data when there is no such signature.
106 size_t parse_signature(const char *buf, unsigned long size)
108 char *eol;
109 size_t len = 0;
110 while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
111 !starts_with(buf + len, PGP_MESSAGE)) {
112 eol = memchr(buf + len, '\n', size - len);
113 len += eol ? eol - (buf + len) + 1 : size - len;
115 return len;
118 void set_signing_key(const char *key)
120 free(configured_signing_key);
121 configured_signing_key = xstrdup(key);
124 int git_gpg_config(const char *var, const char *value, void *cb)
126 if (!strcmp(var, "user.signingkey")) {
127 set_signing_key(value);
129 if (!strcmp(var, "gpg.program")) {
130 if (!value)
131 return config_error_nonbool(var);
132 gpg_program = xstrdup(value);
134 return 0;
137 const char *get_signing_key(void)
139 if (configured_signing_key)
140 return configured_signing_key;
141 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
145 * Create a detached signature for the contents of "buffer" and append
146 * it after "signature"; "buffer" and "signature" can be the same
147 * strbuf instance, which would cause the detached signature appended
148 * at the end.
150 int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
152 struct child_process gpg = CHILD_PROCESS_INIT;
153 const char *args[4];
154 ssize_t len;
155 size_t i, j, bottom;
157 gpg.argv = args;
158 gpg.in = -1;
159 gpg.out = -1;
160 args[0] = gpg_program;
161 args[1] = "-bsau";
162 args[2] = signing_key;
163 args[3] = NULL;
165 if (start_command(&gpg))
166 return error(_("could not run gpg."));
169 * When the username signingkey is bad, program could be terminated
170 * because gpg exits without reading and then write gets SIGPIPE.
172 sigchain_push(SIGPIPE, SIG_IGN);
174 if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
175 close(gpg.in);
176 close(gpg.out);
177 finish_command(&gpg);
178 return error(_("gpg did not accept the data"));
180 close(gpg.in);
182 bottom = signature->len;
183 len = strbuf_read(signature, gpg.out, 1024);
184 close(gpg.out);
186 sigchain_pop(SIGPIPE);
188 if (finish_command(&gpg) || !len || len < 0)
189 return error(_("gpg failed to sign the data"));
191 /* Strip CR from the line endings, in case we are on Windows. */
192 for (i = j = bottom; i < signature->len; i++)
193 if (signature->buf[i] != '\r') {
194 if (i != j)
195 signature->buf[j] = signature->buf[i];
196 j++;
198 strbuf_setlen(signature, j);
200 return 0;
204 * Run "gpg" to see if the payload matches the detached signature.
205 * gpg_output, when set, receives the diagnostic output from GPG.
206 * gpg_status, when set, receives the status output from GPG.
208 int verify_signed_buffer(const char *payload, size_t payload_size,
209 const char *signature, size_t signature_size,
210 struct strbuf *gpg_output, struct strbuf *gpg_status)
212 struct child_process gpg = CHILD_PROCESS_INIT;
213 const char *args_gpg[] = {NULL, "--status-fd=1", "--verify", "FILE", "-", NULL};
214 char path[PATH_MAX];
215 int fd, ret;
216 struct strbuf buf = STRBUF_INIT;
217 struct strbuf *pbuf = &buf;
219 args_gpg[0] = gpg_program;
220 fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
221 if (fd < 0)
222 return error(_("could not create temporary file '%s': %s"),
223 path, strerror(errno));
224 if (write_in_full(fd, signature, signature_size) < 0)
225 return error(_("failed writing detached signature to '%s': %s"),
226 path, strerror(errno));
227 close(fd);
229 gpg.argv = args_gpg;
230 gpg.in = -1;
231 gpg.out = -1;
232 if (gpg_output)
233 gpg.err = -1;
234 args_gpg[3] = path;
235 if (start_command(&gpg)) {
236 unlink(path);
237 return error(_("could not run gpg."));
240 write_in_full(gpg.in, payload, payload_size);
241 close(gpg.in);
243 if (gpg_output) {
244 strbuf_read(gpg_output, gpg.err, 0);
245 close(gpg.err);
247 if (gpg_status)
248 pbuf = gpg_status;
249 strbuf_read(pbuf, gpg.out, 0);
250 close(gpg.out);
252 ret = finish_command(&gpg);
254 unlink_or_warn(path);
256 ret |= !strstr(pbuf->buf, "\n[GNUPG:] GOODSIG ");
257 strbuf_release(&buf); /* no matter it was used or not */
259 return ret;