#include "tempfile.h"
static char *configured_signing_key;
-static const char *gpg_program = "gpg";
+static enum signature_trust_level configured_min_trust_level = TRUST_UNDEFINED;
-#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
-#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
+struct gpg_format {
+ const char *name;
+ const char *program;
+ const char **verify_args;
+ const char **sigs;
+};
+
+static const char *openpgp_verify_args[] = {
+ "--keyid-format=long",
+ NULL
+};
+static const char *openpgp_sigs[] = {
+ "-----BEGIN PGP SIGNATURE-----",
+ "-----BEGIN PGP MESSAGE-----",
+ NULL
+};
+
+static const char *x509_verify_args[] = {
+ NULL
+};
+static const char *x509_sigs[] = {
+ "-----BEGIN SIGNED MESSAGE-----",
+ NULL
+};
+
+static struct gpg_format gpg_format[] = {
+ { .name = "openpgp", .program = "gpg",
+ .verify_args = openpgp_verify_args,
+ .sigs = openpgp_sigs
+ },
+ { .name = "x509", .program = "gpgsm",
+ .verify_args = x509_verify_args,
+ .sigs = x509_sigs
+ },
+};
+
+static struct gpg_format *use_format = &gpg_format[0];
+
+static struct gpg_format *get_format_by_name(const char *str)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
+ if (!strcmp(gpg_format[i].name, str))
+ return gpg_format + i;
+ return NULL;
+}
+
+static struct gpg_format *get_format_by_sig(const char *sig)
+{
+ int i, j;
+
+ for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
+ for (j = 0; gpg_format[i].sigs[j]; j++)
+ if (starts_with(sig, gpg_format[i].sigs[j]))
+ return gpg_format + i;
+ return NULL;
+}
void signature_check_clear(struct signature_check *sigc)
{
FREE_AND_NULL(sigc->gpg_status);
FREE_AND_NULL(sigc->signer);
FREE_AND_NULL(sigc->key);
+ FREE_AND_NULL(sigc->fingerprint);
+ FREE_AND_NULL(sigc->primary_key_fingerprint);
}
+/* An exclusive status -- only one of them can appear in output */
+#define GPG_STATUS_EXCLUSIVE (1<<0)
+/* The status includes key identifier */
+#define GPG_STATUS_KEYID (1<<1)
+/* The status includes user identifier */
+#define GPG_STATUS_UID (1<<2)
+/* The status includes key fingerprints */
+#define GPG_STATUS_FINGERPRINT (1<<3)
+/* The status includes trust level */
+#define GPG_STATUS_TRUST_LEVEL (1<<4)
+
+/* Short-hand for standard exclusive *SIG status with keyid & UID */
+#define GPG_STATUS_STDSIG (GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID|GPG_STATUS_UID)
+
static struct {
char result;
const char *check;
+ unsigned int flags;
} sigcheck_gpg_status[] = {
- { 'G', "\n[GNUPG:] GOODSIG " },
- { 'B', "\n[GNUPG:] BADSIG " },
- { 'U', "\n[GNUPG:] TRUST_NEVER" },
- { 'U', "\n[GNUPG:] TRUST_UNDEFINED" },
- { 'E', "\n[GNUPG:] ERRSIG "},
- { 'X', "\n[GNUPG:] EXPSIG "},
- { 'Y', "\n[GNUPG:] EXPKEYSIG "},
- { 'R', "\n[GNUPG:] REVKEYSIG "},
+ { 'G', "GOODSIG ", GPG_STATUS_STDSIG },
+ { 'B', "BADSIG ", GPG_STATUS_STDSIG },
+ { 'E', "ERRSIG ", GPG_STATUS_EXCLUSIVE|GPG_STATUS_KEYID },
+ { 'X', "EXPSIG ", GPG_STATUS_STDSIG },
+ { 'Y', "EXPKEYSIG ", GPG_STATUS_STDSIG },
+ { 'R', "REVKEYSIG ", GPG_STATUS_STDSIG },
+ { 0, "VALIDSIG ", GPG_STATUS_FINGERPRINT },
+ { 0, "TRUST_", GPG_STATUS_TRUST_LEVEL },
+};
+
+static struct {
+ const char *key;
+ enum signature_trust_level value;
+} sigcheck_gpg_trust_level[] = {
+ { "UNDEFINED", TRUST_UNDEFINED },
+ { "NEVER", TRUST_NEVER },
+ { "MARGINAL", TRUST_MARGINAL },
+ { "FULLY", TRUST_FULLY },
+ { "ULTIMATE", TRUST_ULTIMATE },
};
-void parse_gpg_output(struct signature_check *sigc)
+static void replace_cstring(char **field, const char *line, const char *next)
{
- const char *buf = sigc->gpg_status;
- int i;
+ free(*field);
- /* Iterate over all search strings */
- for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
- const char *found, *next;
+ if (line && next)
+ *field = xmemdupz(line, next - line);
+ else
+ *field = NULL;
+}
- 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);
+static int parse_gpg_trust_level(const char *level,
+ enum signature_trust_level *res)
+{
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_trust_level); i++) {
+ if (!strcmp(sigcheck_gpg_trust_level[i].key, level)) {
+ *res = sigcheck_gpg_trust_level[i].value;
+ return 0;
}
- 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);
- /* The ERRSIG message is not followed by signer information */
- if (sigc-> result != 'E') {
- found += 17;
- next = strchrnul(found, '\n');
- sigc->signer = xmemdupz(found, next - found);
+ }
+ return 1;
+}
+
+static void parse_gpg_output(struct signature_check *sigc)
+{
+ const char *buf = sigc->gpg_status;
+ const char *line, *next;
+ int i, j;
+ int seen_exclusive_status = 0;
+
+ /* Iterate over all lines */
+ for (line = buf; *line; line = strchrnul(line+1, '\n')) {
+ while (*line == '\n')
+ line++;
+ if (!*line)
+ break;
+
+ /* Skip lines that don't start with GNUPG status */
+ if (!skip_prefix(line, "[GNUPG:] ", &line))
+ continue;
+
+ /* Iterate over all search strings */
+ for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
+ if (skip_prefix(line, sigcheck_gpg_status[i].check, &line)) {
+ /*
+ * GOODSIG, BADSIG etc. can occur only once for
+ * each signature. Therefore, if we had more
+ * than one then we're dealing with multiple
+ * signatures. We don't support them
+ * currently, and they're rather hard to
+ * create, so something is likely fishy and we
+ * should reject them altogether.
+ */
+ if (sigcheck_gpg_status[i].flags & GPG_STATUS_EXCLUSIVE) {
+ if (seen_exclusive_status++)
+ goto error;
+ }
+
+ if (sigcheck_gpg_status[i].result)
+ sigc->result = sigcheck_gpg_status[i].result;
+ /* Do we have key information? */
+ if (sigcheck_gpg_status[i].flags & GPG_STATUS_KEYID) {
+ next = strchrnul(line, ' ');
+ replace_cstring(&sigc->key, line, next);
+ /* Do we have signer information? */
+ if (*next && (sigcheck_gpg_status[i].flags & GPG_STATUS_UID)) {
+ line = next + 1;
+ next = strchrnul(line, '\n');
+ replace_cstring(&sigc->signer, line, next);
+ }
+ }
+
+ /* Do we have trust level? */
+ if (sigcheck_gpg_status[i].flags & GPG_STATUS_TRUST_LEVEL) {
+ /*
+ * GPG v1 and v2 differs in how the
+ * TRUST_ lines are written. Some
+ * trust lines contain no additional
+ * space-separated information for v1.
+ */
+ size_t trust_size = strcspn(line, " \n");
+ char *trust = xmemdupz(line, trust_size);
+
+ if (parse_gpg_trust_level(trust, &sigc->trust_level)) {
+ free(trust);
+ goto error;
+ }
+ free(trust);
+ }
+
+ /* Do we have fingerprint? */
+ if (sigcheck_gpg_status[i].flags & GPG_STATUS_FINGERPRINT) {
+ const char *limit;
+ char **field;
+
+ next = strchrnul(line, ' ');
+ replace_cstring(&sigc->fingerprint, line, next);
+
+ /*
+ * Skip interim fields. The search is
+ * limited to the same line since only
+ * OpenPGP signatures has a field with
+ * the primary fingerprint.
+ */
+ limit = strchrnul(line, '\n');
+ for (j = 9; j > 0; j--) {
+ if (!*next || limit <= next)
+ break;
+ line = next + 1;
+ next = strchrnul(line, ' ');
+ }
+
+ field = &sigc->primary_key_fingerprint;
+ if (!j) {
+ next = strchrnul(line, '\n');
+ replace_cstring(field, line, next);
+ } else {
+ replace_cstring(field, NULL, NULL);
+ }
+ }
+
+ break;
}
}
}
+ return;
+
+error:
+ sigc->result = 'E';
+ /* Clear partial data to avoid confusion */
+ FREE_AND_NULL(sigc->primary_key_fingerprint);
+ FREE_AND_NULL(sigc->fingerprint);
+ FREE_AND_NULL(sigc->signer);
+ FREE_AND_NULL(sigc->key);
+}
+
+static 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;
+ struct gpg_format *fmt;
+ struct tempfile *temp;
+ int ret;
+ struct strbuf buf = STRBUF_INIT;
+
+ temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
+ if (!temp)
+ return error_errno(_("could not create temporary file"));
+ if (write_in_full(temp->fd, signature, signature_size) < 0 ||
+ close_tempfile_gently(temp) < 0) {
+ error_errno(_("failed writing detached signature to '%s'"),
+ temp->filename.buf);
+ delete_tempfile(&temp);
+ return -1;
+ }
+
+ fmt = get_format_by_sig(signature);
+ if (!fmt)
+ BUG("bad signature '%s'", signature);
+
+ strvec_push(&gpg.args, fmt->program);
+ strvec_pushv(&gpg.args, fmt->verify_args);
+ strvec_pushl(&gpg.args,
+ "--status-fd=1",
+ "--verify", temp->filename.buf, "-",
+ NULL);
+
+ if (!gpg_status)
+ gpg_status = &buf;
+
+ sigchain_push(SIGPIPE, SIG_IGN);
+ ret = pipe_command(&gpg, payload, payload_size,
+ gpg_status, 0, gpg_output, 0);
+ sigchain_pop(SIGPIPE);
+
+ delete_tempfile(&temp);
+
+ ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
+ strbuf_release(&buf); /* no matter it was used or not */
+
+ return ret;
}
int check_signature(const char *payload, size_t plen, const char *signature,
int status;
sigc->result = 'N';
+ sigc->trust_level = -1;
status = verify_signed_buffer(payload, plen, signature, slen,
&gpg_output, &gpg_status);
sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
parse_gpg_output(sigc);
+ status |= sigc->result != 'G';
+ status |= sigc->trust_level < configured_min_trust_level;
out:
strbuf_release(&gpg_status);
strbuf_release(&gpg_output);
- return sigc->result != 'G' && sigc->result != 'U';
+ return !!status;
}
void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
fputs(output, stderr);
}
-/*
- * 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)
+size_t parse_signature(const char *buf, size_t size)
{
- char *eol;
size_t len = 0;
- while (len < size && !starts_with(buf + len, PGP_SIGNATURE) &&
- !starts_with(buf + len, PGP_MESSAGE)) {
+ size_t match = size;
+ while (len < size) {
+ const char *eol;
+
+ if (get_format_by_sig(buf + len))
+ match = len;
+
eol = memchr(buf + len, '\n', size - len);
len += eol ? eol - (buf + len) + 1 : size - len;
}
- return len;
+ return match;
}
void set_signing_key(const char *key)
int git_gpg_config(const char *var, const char *value, void *cb)
{
+ struct gpg_format *fmt = NULL;
+ char *fmtname = NULL;
+ char *trust;
+ int ret;
+
if (!strcmp(var, "user.signingkey")) {
+ if (!value)
+ return config_error_nonbool(var);
set_signing_key(value);
+ return 0;
}
- if (!strcmp(var, "gpg.program")) {
+
+ if (!strcmp(var, "gpg.format")) {
+ if (!value)
+ return config_error_nonbool(var);
+ fmt = get_format_by_name(value);
+ if (!fmt)
+ return error("unsupported value for %s: %s",
+ var, value);
+ use_format = fmt;
+ return 0;
+ }
+
+ if (!strcmp(var, "gpg.mintrustlevel")) {
if (!value)
return config_error_nonbool(var);
- gpg_program = xstrdup(value);
+
+ trust = xstrdup_toupper(value);
+ ret = parse_gpg_trust_level(trust, &configured_min_trust_level);
+ free(trust);
+
+ if (ret)
+ return error("unsupported value for %s: %s", var,
+ value);
+ return 0;
}
+
+ if (!strcmp(var, "gpg.program") || !strcmp(var, "gpg.openpgp.program"))
+ fmtname = "openpgp";
+
+ if (!strcmp(var, "gpg.x509.program"))
+ fmtname = "x509";
+
+ if (fmtname) {
+ fmt = get_format_by_name(fmtname);
+ return git_config_string(&fmt->program, var, value);
+ }
+
return 0;
}
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;
size_t i, j, bottom;
struct strbuf gpg_status = STRBUF_INIT;
- argv_array_pushl(&gpg.args,
- gpg_program,
- "--status-fd=2",
- "-bsau", signing_key,
- NULL);
+ strvec_pushl(&gpg.args,
+ use_format->program,
+ "--status-fd=2",
+ "-bsau", signing_key,
+ NULL);
bottom = signature->len;
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;
- struct tempfile *temp;
- int ret;
- struct strbuf buf = STRBUF_INIT;
-
- temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
- if (!temp)
- return error_errno(_("could not create temporary file"));
- if (write_in_full(temp->fd, signature, signature_size) < 0 ||
- close_tempfile_gently(temp) < 0) {
- error_errno(_("failed writing detached signature to '%s'"),
- temp->filename.buf);
- delete_tempfile(&temp);
- return -1;
- }
-
- argv_array_pushl(&gpg.args,
- gpg_program,
- "--status-fd=1",
- "--keyid-format=long",
- "--verify", temp->filename.buf, "-",
- NULL);
-
- if (!gpg_status)
- gpg_status = &buf;
-
- sigchain_push(SIGPIPE, SIG_IGN);
- ret = pipe_command(&gpg, payload, payload_size,
- gpg_status, 0, gpg_output, 0);
- sigchain_pop(SIGPIPE);
-
- delete_tempfile(&temp);
-
- ret |= !strstr(gpg_status->buf, "\n[GNUPG:] GOODSIG ");
- strbuf_release(&buf); /* no matter it was used or not */
-
- return ret;
-}