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1 | #include "cache.h" | |
2 | #include "config.h" | |
3 | #include "run-command.h" | |
4 | #include "strbuf.h" | |
5 | #include "gpg-interface.h" | |
6 | #include "sigchain.h" | |
7 | #include "tempfile.h" | |
8 | ||
9 | static char *configured_signing_key; | |
10 | static const char *gpg_program = "gpg"; | |
11 | ||
12 | #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----" | |
13 | #define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----" | |
14 | ||
15 | void signature_check_clear(struct signature_check *sigc) | |
16 | { | |
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); | |
22 | } | |
23 | ||
24 | static 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" }, | |
32 | { 'E', "\n[GNUPG:] ERRSIG "}, | |
33 | { 'X', "\n[GNUPG:] EXPSIG "}, | |
34 | { 'Y', "\n[GNUPG:] EXPKEYSIG "}, | |
35 | { 'R', "\n[GNUPG:] REVKEYSIG "}, | |
36 | }; | |
37 | ||
38 | void 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); | |
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 | } | |
63 | } | |
64 | } | |
65 | } | |
66 | ||
67 | int check_signature(const char *payload, size_t plen, const char *signature, | |
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); | |
88 | ||
89 | return sigc->result != 'G' && sigc->result != 'U'; | |
90 | } | |
91 | ||
92 | void print_signature_buffer(const struct signature_check *sigc, unsigned flags) | |
93 | { | |
94 | const char *output = flags & GPG_VERIFY_RAW ? | |
95 | sigc->gpg_status : sigc->gpg_output; | |
96 | ||
97 | if (flags & GPG_VERIFY_VERBOSE && sigc->payload) | |
98 | fputs(sigc->payload, stdout); | |
99 | ||
100 | if (output) | |
101 | fputs(output, stderr); | |
102 | } | |
103 | ||
104 | static int is_gpg_start(const char *line) | |
105 | { | |
106 | return starts_with(line, PGP_SIGNATURE) || | |
107 | starts_with(line, PGP_MESSAGE); | |
108 | } | |
109 | ||
110 | size_t parse_signature(const char *buf, size_t size) | |
111 | { | |
112 | size_t len = 0; | |
113 | size_t match = size; | |
114 | while (len < size) { | |
115 | const char *eol; | |
116 | ||
117 | if (is_gpg_start(buf + len)) | |
118 | match = len; | |
119 | ||
120 | eol = memchr(buf + len, '\n', size - len); | |
121 | len += eol ? eol - (buf + len) + 1 : size - len; | |
122 | } | |
123 | return match; | |
124 | } | |
125 | ||
126 | void set_signing_key(const char *key) | |
127 | { | |
128 | free(configured_signing_key); | |
129 | configured_signing_key = xstrdup(key); | |
130 | } | |
131 | ||
132 | int git_gpg_config(const char *var, const char *value, void *cb) | |
133 | { | |
134 | if (!strcmp(var, "user.signingkey")) { | |
135 | if (!value) | |
136 | return config_error_nonbool(var); | |
137 | set_signing_key(value); | |
138 | return 0; | |
139 | } | |
140 | ||
141 | if (!strcmp(var, "gpg.program")) { | |
142 | if (!value) | |
143 | return config_error_nonbool(var); | |
144 | gpg_program = xstrdup(value); | |
145 | return 0; | |
146 | } | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | const char *get_signing_key(void) | |
152 | { | |
153 | if (configured_signing_key) | |
154 | return configured_signing_key; | |
155 | return git_committer_info(IDENT_STRICT|IDENT_NO_DATE); | |
156 | } | |
157 | ||
158 | int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key) | |
159 | { | |
160 | struct child_process gpg = CHILD_PROCESS_INIT; | |
161 | int ret; | |
162 | size_t i, j, bottom; | |
163 | struct strbuf gpg_status = STRBUF_INIT; | |
164 | ||
165 | argv_array_pushl(&gpg.args, | |
166 | gpg_program, | |
167 | "--status-fd=2", | |
168 | "-bsau", signing_key, | |
169 | NULL); | |
170 | ||
171 | bottom = signature->len; | |
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); | |
178 | ret = pipe_command(&gpg, buffer->buf, buffer->len, | |
179 | signature, 1024, &gpg_status, 0); | |
180 | sigchain_pop(SIGPIPE); | |
181 | ||
182 | ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED "); | |
183 | strbuf_release(&gpg_status); | |
184 | if (ret) | |
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 | int verify_signed_buffer(const char *payload, size_t payload_size, | |
200 | const char *signature, size_t signature_size, | |
201 | struct strbuf *gpg_output, struct strbuf *gpg_status) | |
202 | { | |
203 | struct child_process gpg = CHILD_PROCESS_INIT; | |
204 | struct tempfile *temp; | |
205 | int ret; | |
206 | struct strbuf buf = STRBUF_INIT; | |
207 | ||
208 | temp = mks_tempfile_t(".git_vtag_tmpXXXXXX"); | |
209 | if (!temp) | |
210 | return error_errno(_("could not create temporary file")); | |
211 | if (write_in_full(temp->fd, signature, signature_size) < 0 || | |
212 | close_tempfile_gently(temp) < 0) { | |
213 | error_errno(_("failed writing detached signature to '%s'"), | |
214 | temp->filename.buf); | |
215 | delete_tempfile(&temp); | |
216 | return -1; | |
217 | } | |
218 | ||
219 | argv_array_pushl(&gpg.args, | |
220 | gpg_program, | |
221 | "--status-fd=1", | |
222 | "--keyid-format=long", | |
223 | "--verify", temp->filename.buf, "-", | |
224 | NULL); | |
225 | ||
226 | if (!gpg_status) | |
227 | gpg_status = &buf; | |
228 | ||
229 | sigchain_push(SIGPIPE, SIG_IGN); | |
230 | ret = pipe_command(&gpg, payload, payload_size, | |
231 | gpg_status, 0, gpg_output, 0); | |
232 | sigchain_pop(SIGPIPE); | |
233 | ||
234 | delete_tempfile(&temp); | |
235 | ||
236 | ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG "); | |
237 | strbuf_release(&buf); /* no matter it was used or not */ | |
238 | ||
239 | return ret; | |
240 | } |