Git 2.1
[git/git.git] / gpg-interface.c
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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"
6
7static char *configured_signing_key;
0c5e70f0 8static const char *gpg_program = "gpg";
2f47eae2 9
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10void signature_check_clear(struct signature_check *sigc)
11{
71c214c8 12 free(sigc->payload);
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13 free(sigc->gpg_output);
14 free(sigc->gpg_status);
15 free(sigc->signer);
16 free(sigc->key);
71c214c8 17 sigc->payload = NULL;
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18 sigc->gpg_output = NULL;
19 sigc->gpg_status = NULL;
20 sigc->signer = NULL;
21 sigc->key = NULL;
22}
23
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24void set_signing_key(const char *key)
25{
26 free(configured_signing_key);
27 configured_signing_key = xstrdup(key);
28}
29
30int git_gpg_config(const char *var, const char *value, void *cb)
31{
32 if (!strcmp(var, "user.signingkey")) {
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33 set_signing_key(value);
34 }
35 if (!strcmp(var, "gpg.program")) {
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36 if (!value)
37 return config_error_nonbool(var);
0c5e70f0 38 gpg_program = xstrdup(value);
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39 }
40 return 0;
41}
42
43const char *get_signing_key(void)
44{
45 if (configured_signing_key)
46 return configured_signing_key;
f9bc573f 47 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
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48}
49
50/*
51 * Create a detached signature for the contents of "buffer" and append
52 * it after "signature"; "buffer" and "signature" can be the same
53 * strbuf instance, which would cause the detached signature appended
54 * at the end.
55 */
56int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
57{
58 struct child_process gpg;
59 const char *args[4];
60 ssize_t len;
61 size_t i, j, bottom;
62
63 memset(&gpg, 0, sizeof(gpg));
64 gpg.argv = args;
65 gpg.in = -1;
66 gpg.out = -1;
0c5e70f0 67 args[0] = gpg_program;
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68 args[1] = "-bsau";
69 args[2] = signing_key;
70 args[3] = NULL;
71
72 if (start_command(&gpg))
73 return error(_("could not run gpg."));
74
75 /*
76 * When the username signingkey is bad, program could be terminated
77 * because gpg exits without reading and then write gets SIGPIPE.
78 */
79 sigchain_push(SIGPIPE, SIG_IGN);
80
81 if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
82 close(gpg.in);
83 close(gpg.out);
84 finish_command(&gpg);
85 return error(_("gpg did not accept the data"));
86 }
87 close(gpg.in);
88
89 bottom = signature->len;
90 len = strbuf_read(signature, gpg.out, 1024);
91 close(gpg.out);
92
93 sigchain_pop(SIGPIPE);
94
95 if (finish_command(&gpg) || !len || len < 0)
96 return error(_("gpg failed to sign the data"));
97
98 /* Strip CR from the line endings, in case we are on Windows. */
99 for (i = j = bottom; i < signature->len; i++)
100 if (signature->buf[i] != '\r') {
101 if (i != j)
102 signature->buf[j] = signature->buf[i];
103 j++;
104 }
105 strbuf_setlen(signature, j);
106
107 return 0;
108}
109
110/*
111 * Run "gpg" to see if the payload matches the detached signature.
e3f55e07 112 * gpg_output, when set, receives the diagnostic output from GPG.
b60b7566 113 * gpg_status, when set, receives the status output from GPG.
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114 */
115int verify_signed_buffer(const char *payload, size_t payload_size,
116 const char *signature, size_t signature_size,
9cc4ac8f 117 struct strbuf *gpg_output, struct strbuf *gpg_status)
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118{
119 struct child_process gpg;
b60b7566 120 const char *args_gpg[] = {NULL, "--status-fd=1", "--verify", "FILE", "-", NULL};
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121 char path[PATH_MAX];
122 int fd, ret;
b60b7566 123 struct strbuf buf = STRBUF_INIT;
9cc4ac8f 124 struct strbuf *pbuf = &buf;
2f47eae2 125
0c5e70f0 126 args_gpg[0] = gpg_program;
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127 fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
128 if (fd < 0)
4c9a4182 129 return error(_("could not create temporary file '%s': %s"),
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130 path, strerror(errno));
131 if (write_in_full(fd, signature, signature_size) < 0)
4c9a4182 132 return error(_("failed writing detached signature to '%s': %s"),
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133 path, strerror(errno));
134 close(fd);
135
136 memset(&gpg, 0, sizeof(gpg));
137 gpg.argv = args_gpg;
138 gpg.in = -1;
b60b7566 139 gpg.out = -1;
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140 if (gpg_output)
141 gpg.err = -1;
b60b7566 142 args_gpg[3] = path;
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143 if (start_command(&gpg)) {
144 unlink(path);
4c9a4182 145 return error(_("could not run gpg."));
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146 }
147
148 write_in_full(gpg.in, payload, payload_size);
149 close(gpg.in);
150
7dac3f83 151 if (gpg_output) {
2f47eae2 152 strbuf_read(gpg_output, gpg.err, 0);
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153 close(gpg.err);
154 }
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155 if (gpg_status)
156 pbuf = gpg_status;
157 strbuf_read(pbuf, gpg.out, 0);
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158 close(gpg.out);
159
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160 ret = finish_command(&gpg);
161
162 unlink_or_warn(path);
163
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164 ret |= !strstr(pbuf->buf, "\n[GNUPG:] GOODSIG ");
165 strbuf_release(&buf); /* no matter it was used or not */
b60b7566 166
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167 return ret;
168}