1 files changed, 183 insertions, 45 deletions

diff --git a/gpg-interface.c b/gpg-interface.c
index 09ddfbc267..8ed274533f 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -7,10 +7,64 @@
 #include "tempfile.h"
 
 static char *configured_signing_key;
-static const char *gpg_program = "gpg";
+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
+};
 
-#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
-#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
+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)
 {
@@ -19,49 +73,115 @@ 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)
+
+/* 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 },
+	{ 'U', "TRUST_NEVER", 0 },
+	{ 'U', "TRUST_UNDEFINED", 0 },
+	{ '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 },
 };
 
 static 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);
-			/* 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);
+	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++;
+		/* 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)) {
+				if (sigcheck_gpg_status[i].flags & GPG_STATUS_EXCLUSIVE) {
+					if (seen_exclusive_status++)
+						goto found_duplicate_status;
+				}
+
+				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, ' ');
+					free(sigc->key);
+					sigc->key = xmemdupz(line, next - line);
+					/* Do we have signer information? */
+					if (*next && (sigcheck_gpg_status[i].flags & GPG_STATUS_UID)) {
+						line = next + 1;
+						next = strchrnul(line, '\n');
+						free(sigc->signer);
+						sigc->signer = xmemdupz(line, next - line);
+					}
+				}
+				/* Do we have fingerprint? */
+				if (sigcheck_gpg_status[i].flags & GPG_STATUS_FINGERPRINT) {
+					next = strchrnul(line, ' ');
+					free(sigc->fingerprint);
+					sigc->fingerprint = xmemdupz(line, next - line);
+
+					/* Skip interim fields */
+					for (j = 9; j > 0; j--) {
+						if (!*next)
+							break;
+						line = next + 1;
+						next = strchrnul(line, ' ');
+					}
+
+					next = strchrnul(line, '\n');
+					free(sigc->primary_key_fingerprint);
+					sigc->primary_key_fingerprint = xmemdupz(line, next - line);
+				}
+
+				break;
 			}
 		}
 	}
+	return;
+
+found_duplicate_status:
+	/*
+	 * 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.
+	 */
+	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);
 }
 
 int check_signature(const char *payload, size_t plen, const char *signature,
@@ -81,12 +201,13 @@ int check_signature(const char *payload, size_t plen, const char *signature,
 	sigc->gpg_output = strbuf_detach(&gpg_output, NULL);
 	sigc->gpg_status = strbuf_detach(&gpg_status, NULL);
 	parse_gpg_output(sigc);
+	status |= sigc->result != 'G' && sigc->result != 'U';
 
  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)
@@ -101,12 +222,6 @@ void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
 		fputs(output, stderr);
 }
 
-static int is_gpg_start(const char *line)
-{
-	return starts_with(line, PGP_SIGNATURE) ||
-		starts_with(line, PGP_MESSAGE);
-}
-
 size_t parse_signature(const char *buf, size_t size)
 {
 	size_t len = 0;
@@ -114,7 +229,7 @@ size_t parse_signature(const char *buf, size_t size)
 	while (len < size) {
 		const char *eol;
 
-		if (is_gpg_start(buf + len))
+		if (get_format_by_sig(buf + len))
 			match = len;
 
 		eol = memchr(buf + len, '\n', size - len);
@@ -131,6 +246,9 @@ 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;
+
 	if (!strcmp(var, "user.signingkey")) {
 		if (!value)
 			return config_error_nonbool(var);
@@ -138,13 +256,28 @@ int git_gpg_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!strcmp(var, "gpg.program")) {
+	if (!strcmp(var, "gpg.format")) {
 		if (!value)
 			return config_error_nonbool(var);
-		gpg_program = xstrdup(value);
+		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.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;
 }
 
@@ -163,7 +296,7 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *sig
 	struct strbuf gpg_status = STRBUF_INIT;
 
 	argv_array_pushl(&gpg.args,
-			 gpg_program,
+			 use_format->program,
 			 "--status-fd=2",
 			 "-bsau", signing_key,
 			 NULL);
@@ -201,6 +334,7 @@ int verify_signed_buffer(const char *payload, size_t payload_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;
@@ -216,10 +350,14 @@ int verify_signed_buffer(const char *payload, size_t payload_size,
 		return -1;
 	}
 
+	fmt = get_format_by_sig(signature);
+	if (!fmt)
+		BUG("bad signature '%s'", signature);
+
+	argv_array_push(&gpg.args, fmt->program);
+	argv_array_pushv(&gpg.args, fmt->verify_args);
 	argv_array_pushl(&gpg.args,
-			 gpg_program,
 			 "--status-fd=1",
-			 "--keyid-format=long",
 			 "--verify", temp->filename.buf, "-",
 			 NULL);