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-rw-r--r--gpg-interface.c312
1 files changed, 234 insertions, 78 deletions
diff --git a/gpg-interface.c b/gpg-interface.c
index db17d65f8a..2d538bcd6e 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -7,6 +7,8 @@
#include "tempfile.h"
static char *configured_signing_key;
+static enum signature_trust_level configured_min_trust_level = TRUST_UNDEFINED;
+
struct gpg_format {
const char *name;
const char *program;
@@ -73,50 +75,234 @@ 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 void parse_gpg_output(struct signature_check *sigc)
+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 },
+};
+
+static void replace_cstring(char **field, const char *line, const char *next)
{
- const char *buf = sigc->gpg_status;
- int i;
+ free(*field);
+
+ if (line && next)
+ *field = xmemdupz(line, next - line);
+ else
+ *field = NULL;
+}
- /* Iterate over all search strings */
- for (i = 0; i < ARRAY_SIZE(sigcheck_gpg_status); i++) {
- const char *found, *next;
+static int parse_gpg_trust_level(const char *level,
+ enum signature_trust_level *res)
+{
+ size_t i;
- 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);
+ 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') {
- next = strchrnul(found, ' ');
- sigc->key = xmemdupz(found, next - found);
- /* The ERRSIG message is not followed by signer information */
- if (*next && sigc-> result != 'E') {
- found = next + 1;
- 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);
+
+ argv_array_push(&gpg.args, fmt->program);
+ argv_array_pushv(&gpg.args, fmt->verify_args);
+ argv_array_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,
@@ -127,6 +313,7 @@ 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);
@@ -136,7 +323,8 @@ 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';
+ status |= sigc->result != 'G';
+ status |= sigc->trust_level < configured_min_trust_level;
out:
strbuf_release(&gpg_status);
@@ -183,6 +371,8 @@ 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)
@@ -202,6 +392,20 @@ int git_gpg_config(const char *var, const char *value, void *cb)
return 0;
}
+ if (!strcmp(var, "gpg.mintrustlevel")) {
+ if (!value)
+ return config_error_nonbool(var);
+
+ 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";
@@ -263,51 +467,3 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *sig
return 0;
}
-
-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);
-
- argv_array_push(&gpg.args, fmt->program);
- argv_array_pushv(&gpg.args, fmt->verify_args);
- argv_array_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;
-}