Merge branch 'mh/write-refs-sooner-2.4' into maint
[git.git] / gpg-interface.c
blob68b0c814f789f39151d380b1d318d6f80090d524
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);
64 * Look at GPG signed content (e.g. a signed tag object), whose
65 * payload is followed by a detached signature on it. Return the
66 * offset where the embedded detached signature begins, or the end of
67 * the data when there is no such signature.
69 size_t parse_signature(const char *buf, unsigned long size)
71 char *eol;
72 size_t len = 0;
73 while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
74 !starts_with(buf + len, PGP_MESSAGE)) {
75 eol = memchr(buf + len, '\n', size - len);
76 len += eol ? eol - (buf + len) + 1 : size - len;
78 return len;
81 void set_signing_key(const char *key)
83 free(configured_signing_key);
84 configured_signing_key = xstrdup(key);
87 int git_gpg_config(const char *var, const char *value, void *cb)
89 if (!strcmp(var, "user.signingkey")) {
90 set_signing_key(value);
92 if (!strcmp(var, "gpg.program")) {
93 if (!value)
94 return config_error_nonbool(var);
95 gpg_program = xstrdup(value);
97 return 0;
100 const char *get_signing_key(void)
102 if (configured_signing_key)
103 return configured_signing_key;
104 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
108 * Create a detached signature for the contents of "buffer" and append
109 * it after "signature"; "buffer" and "signature" can be the same
110 * strbuf instance, which would cause the detached signature appended
111 * at the end.
113 int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
115 struct child_process gpg = CHILD_PROCESS_INIT;
116 const char *args[4];
117 ssize_t len;
118 size_t i, j, bottom;
120 gpg.argv = args;
121 gpg.in = -1;
122 gpg.out = -1;
123 args[0] = gpg_program;
124 args[1] = "-bsau";
125 args[2] = signing_key;
126 args[3] = NULL;
128 if (start_command(&gpg))
129 return error(_("could not run gpg."));
132 * When the username signingkey is bad, program could be terminated
133 * because gpg exits without reading and then write gets SIGPIPE.
135 sigchain_push(SIGPIPE, SIG_IGN);
137 if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
138 close(gpg.in);
139 close(gpg.out);
140 finish_command(&gpg);
141 return error(_("gpg did not accept the data"));
143 close(gpg.in);
145 bottom = signature->len;
146 len = strbuf_read(signature, gpg.out, 1024);
147 close(gpg.out);
149 sigchain_pop(SIGPIPE);
151 if (finish_command(&gpg) || !len || len < 0)
152 return error(_("gpg failed to sign the data"));
154 /* Strip CR from the line endings, in case we are on Windows. */
155 for (i = j = bottom; i < signature->len; i++)
156 if (signature->buf[i] != '\r') {
157 if (i != j)
158 signature->buf[j] = signature->buf[i];
159 j++;
161 strbuf_setlen(signature, j);
163 return 0;
167 * Run "gpg" to see if the payload matches the detached signature.
168 * gpg_output, when set, receives the diagnostic output from GPG.
169 * gpg_status, when set, receives the status output from GPG.
171 int verify_signed_buffer(const char *payload, size_t payload_size,
172 const char *signature, size_t signature_size,
173 struct strbuf *gpg_output, struct strbuf *gpg_status)
175 struct child_process gpg = CHILD_PROCESS_INIT;
176 const char *args_gpg[] = {NULL, "--status-fd=1", "--verify", "FILE", "-", NULL};
177 char path[PATH_MAX];
178 int fd, ret;
179 struct strbuf buf = STRBUF_INIT;
180 struct strbuf *pbuf = &buf;
182 args_gpg[0] = gpg_program;
183 fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
184 if (fd < 0)
185 return error(_("could not create temporary file '%s': %s"),
186 path, strerror(errno));
187 if (write_in_full(fd, signature, signature_size) < 0)
188 return error(_("failed writing detached signature to '%s': %s"),
189 path, strerror(errno));
190 close(fd);
192 gpg.argv = args_gpg;
193 gpg.in = -1;
194 gpg.out = -1;
195 if (gpg_output)
196 gpg.err = -1;
197 args_gpg[3] = path;
198 if (start_command(&gpg)) {
199 unlink(path);
200 return error(_("could not run gpg."));
203 write_in_full(gpg.in, payload, payload_size);
204 close(gpg.in);
206 if (gpg_output) {
207 strbuf_read(gpg_output, gpg.err, 0);
208 close(gpg.err);
210 if (gpg_status)
211 pbuf = gpg_status;
212 strbuf_read(pbuf, gpg.out, 0);
213 close(gpg.out);
215 ret = finish_command(&gpg);
217 unlink_or_warn(path);
219 ret |= !strstr(pbuf->buf, "\n[GNUPG:] GOODSIG ");
220 strbuf_release(&buf); /* no matter it was used or not */
222 return ret;