Merge git://ozlabs.org/~paulus/gitk
[git/git.git] / gpg-interface.c
CommitLineData
2f47eae2
JH
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
JH
9
10void set_signing_key(const char *key)
11{
12 free(configured_signing_key);
13 configured_signing_key = xstrdup(key);
14}
15
16int git_gpg_config(const char *var, const char *value, void *cb)
17{
18 if (!strcmp(var, "user.signingkey")) {
0c5e70f0
JH
19 set_signing_key(value);
20 }
21 if (!strcmp(var, "gpg.program")) {
2f47eae2
JH
22 if (!value)
23 return config_error_nonbool(var);
0c5e70f0 24 gpg_program = xstrdup(value);
2f47eae2
JH
25 }
26 return 0;
27}
28
29const char *get_signing_key(void)
30{
31 if (configured_signing_key)
32 return configured_signing_key;
f9bc573f 33 return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
2f47eae2
JH
34}
35
36/*
37 * Create a detached signature for the contents of "buffer" and append
38 * it after "signature"; "buffer" and "signature" can be the same
39 * strbuf instance, which would cause the detached signature appended
40 * at the end.
41 */
42int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
43{
44 struct child_process gpg;
45 const char *args[4];
46 ssize_t len;
47 size_t i, j, bottom;
48
49 memset(&gpg, 0, sizeof(gpg));
50 gpg.argv = args;
51 gpg.in = -1;
52 gpg.out = -1;
0c5e70f0 53 args[0] = gpg_program;
2f47eae2
JH
54 args[1] = "-bsau";
55 args[2] = signing_key;
56 args[3] = NULL;
57
58 if (start_command(&gpg))
59 return error(_("could not run gpg."));
60
61 /*
62 * When the username signingkey is bad, program could be terminated
63 * because gpg exits without reading and then write gets SIGPIPE.
64 */
65 sigchain_push(SIGPIPE, SIG_IGN);
66
67 if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
68 close(gpg.in);
69 close(gpg.out);
70 finish_command(&gpg);
71 return error(_("gpg did not accept the data"));
72 }
73 close(gpg.in);
74
75 bottom = signature->len;
76 len = strbuf_read(signature, gpg.out, 1024);
77 close(gpg.out);
78
79 sigchain_pop(SIGPIPE);
80
81 if (finish_command(&gpg) || !len || len < 0)
82 return error(_("gpg failed to sign the data"));
83
84 /* Strip CR from the line endings, in case we are on Windows. */
85 for (i = j = bottom; i < signature->len; i++)
86 if (signature->buf[i] != '\r') {
87 if (i != j)
88 signature->buf[j] = signature->buf[i];
89 j++;
90 }
91 strbuf_setlen(signature, j);
92
93 return 0;
94}
95
96/*
97 * Run "gpg" to see if the payload matches the detached signature.
e3f55e07 98 * gpg_output, when set, receives the diagnostic output from GPG.
2f47eae2
JH
99 */
100int verify_signed_buffer(const char *payload, size_t payload_size,
101 const char *signature, size_t signature_size,
102 struct strbuf *gpg_output)
103{
104 struct child_process gpg;
0c5e70f0 105 const char *args_gpg[] = {NULL, "--verify", "FILE", "-", NULL};
2f47eae2
JH
106 char path[PATH_MAX];
107 int fd, ret;
108
0c5e70f0 109 args_gpg[0] = gpg_program;
2f47eae2
JH
110 fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
111 if (fd < 0)
112 return error("could not create temporary file '%s': %s",
113 path, strerror(errno));
114 if (write_in_full(fd, signature, signature_size) < 0)
115 return error("failed writing detached signature to '%s': %s",
116 path, strerror(errno));
117 close(fd);
118
119 memset(&gpg, 0, sizeof(gpg));
120 gpg.argv = args_gpg;
121 gpg.in = -1;
122 if (gpg_output)
123 gpg.err = -1;
124 args_gpg[2] = path;
125 if (start_command(&gpg)) {
126 unlink(path);
127 return error("could not run gpg.");
128 }
129
130 write_in_full(gpg.in, payload, payload_size);
131 close(gpg.in);
132
133 if (gpg_output)
134 strbuf_read(gpg_output, gpg.err, 0);
135 ret = finish_command(&gpg);
136
137 unlink_or_warn(path);
138
139 return ret;
140}