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#include "cache.h"
#include "run-command.h"
#include "strbuf.h"
#include "gpg-interface.h"
#include "sigchain.h"
static char *configured_signing_key;
static const char *gpg_program = "gpg";
#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
void signature_check_clear(struct signature_check *sigc)
{
free(sigc->payload);
free(sigc->gpg_output);
free(sigc->gpg_status);
free(sigc->signer);
free(sigc->key);
sigc->payload = NULL;
sigc->gpg_output = NULL;
sigc->gpg_status = NULL;
sigc->signer = NULL;
sigc->key = NULL;
}
static struct {
char result;
const char *check;
} sigcheck_gpg_status[] = {
{ 'G', "\n[GNUPG:] GOODSIG " },
{ 'B', "\n[GNUPG:] BADSIG " },
{ 'U', "\n[GNUPG:] TRUST_NEVER" },
{ 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
};
void parse_gpg_output(struct signature_check *sigc)
{
const char *buf = sigc->gpg_status;
int i;
/* Iterate over all search strings */
for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
const char *found, *next;
if (!skip_prefix(buf, sigcheck_gpg_status[i].check + 1, &found)) {
found = strstr(buf, sigcheck_gpg_status[i].check);
if (!found)
continue;
found += strlen(sigcheck_gpg_status[i].check);
}
sigc->result = sigcheck_gpg_status[i].result;
/* The trust messages are not followed by key/signer information */
if (sigc->result != 'U') {
sigc->key = xmemdupz(found, 16);
found += 17;
next = strchrnul(found, '\n');
sigc->signer = xmemdupz(found, next - found);
}
}
}
/*
* Look at GPG signed content (e.g. a signed tag object), whose
* payload is followed by a detached signature on it. Return the
* offset where the embedded detached signature begins, or the end of
* the data when there is no such signature.
*/
size_t parse_signature(const char *buf, unsigned long size)
{
char *eol;
size_t len = 0;
while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
!starts_with(buf + len, PGP_MESSAGE)) {
eol = memchr(buf + len, '\n', size - len);
len += eol ? eol - (buf + len) + 1 : size - len;
}
return len;
}
void set_signing_key(const char *key)
{
free(configured_signing_key);
configured_signing_key = xstrdup(key);
}
int git_gpg_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "user.signingkey")) {
set_signing_key(value);
}
if (!strcmp(var, "gpg.program")) {
if (!value)
return config_error_nonbool(var);
gpg_program = xstrdup(value);
}
return 0;
}
const char *get_signing_key(void)
{
if (configured_signing_key)
return configured_signing_key;
return git_committer_info(IDENT_STRICT|IDENT_NO_DATE);
}
/*
* Create a detached signature for the contents of "buffer" and append
* it after "signature"; "buffer" and "signature" can be the same
* strbuf instance, which would cause the detached signature appended
* at the end.
*/
int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
{
struct child_process gpg = CHILD_PROCESS_INIT;
const char *args[4];
ssize_t len;
size_t i, j, bottom;
gpg.argv = args;
gpg.in = -1;
gpg.out = -1;
args[0] = gpg_program;
args[1] = "-bsau";
args[2] = signing_key;
args[3] = NULL;
if (start_command(&gpg))
return error(_("could not run gpg."));
/*
* When the username signingkey is bad, program could be terminated
* because gpg exits without reading and then write gets SIGPIPE.
*/
sigchain_push(SIGPIPE, SIG_IGN);
if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) {
close(gpg.in);
close(gpg.out);
finish_command(&gpg);
return error(_("gpg did not accept the data"));
}
close(gpg.in);
bottom = signature->len;
len = strbuf_read(signature, gpg.out, 1024);
close(gpg.out);
sigchain_pop(SIGPIPE);
if (finish_command(&gpg) || !len || len < 0)
return error(_("gpg failed to sign the data"));
/* Strip CR from the line endings, in case we are on Windows. */
for (i = j = bottom; i < signature->len; i++)
if (signature->buf[i] != '\r') {
if (i != j)
signature->buf[j] = signature->buf[i];
j++;
}
strbuf_setlen(signature, j);
return 0;
}
/*
* Run "gpg" to see if the payload matches the detached signature.
* gpg_output, when set, receives the diagnostic output from GPG.
* gpg_status, when set, receives the status output from GPG.
*/
int verify_signed_buffer(const char *payload, size_t payload_size,
const char *signature, size_t signature_size,
struct strbuf *gpg_output, struct strbuf *gpg_status)
{
struct child_process gpg = CHILD_PROCESS_INIT;
const char *args_gpg[] = {NULL, "--status-fd=1", "--verify", "FILE", "-", NULL};
char path[PATH_MAX];
int fd, ret;
struct strbuf buf = STRBUF_INIT;
struct strbuf *pbuf = &buf;
args_gpg[0] = gpg_program;
fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX");
if (fd < 0)
return error(_("could not create temporary file '%s': %s"),
path, strerror(errno));
if (write_in_full(fd, signature, signature_size) < 0)
return error(_("failed writing detached signature to '%s': %s"),
path, strerror(errno));
close(fd);
gpg.argv = args_gpg;
gpg.in = -1;
gpg.out = -1;
if (gpg_output)
gpg.err = -1;
args_gpg[3] = path;
if (start_command(&gpg)) {
unlink(path);
return error(_("could not run gpg."));
}
write_in_full(gpg.in, payload, payload_size);
close(gpg.in);
if (gpg_output) {
strbuf_read(gpg_output, gpg.err, 0);
close(gpg.err);
}
if (gpg_status)
pbuf = gpg_status;
strbuf_read(pbuf, gpg.out, 0);
close(gpg.out);
ret = finish_command(&gpg);
unlink_or_warn(path);
ret |= !strstr(pbuf->buf, "\n[GNUPG:] GOODSIG ");
strbuf_release(&buf); /* no matter it was used or not */
return ret;
}
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