#include "cache.h"
+#include "config.h"
#include "run-command.h"
#include "strbuf.h"
#include "gpg-interface.h"
#include "sigchain.h"
+#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;
+
+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->payload);
+ FREE_AND_NULL(sigc->gpg_output);
+ 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', "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 },
+};
+
+static void replace_cstring(char **field, const char *line, const char *next)
+{
+ free(*field);
+
+ if (line && next)
+ *field = xmemdupz(line, next - line);
+ else
+ *field = NULL;
+}
+
+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;
+ }
+ }
+ 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,
+ size_t slen, struct signature_check *sigc)
+{
+ struct strbuf gpg_output = STRBUF_INIT;
+ struct strbuf gpg_status = STRBUF_INIT;
+ int status;
+
+ sigc->result = 'N';
+ sigc->trust_level = -1;
+
+ status = verify_signed_buffer(payload, plen, signature, slen,
+ &gpg_output, &gpg_status);
+ if (status && !gpg_output.len)
+ goto out;
+ sigc->payload = xmemdupz(payload, plen);
+ 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 !!status;
+}
+
+void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
+{
+ const char *output = flags & GPG_VERIFY_RAW ?
+ sigc->gpg_status : sigc->gpg_output;
+
+ if (flags & GPG_VERIFY_VERBOSE && sigc->payload)
+ fputs(sigc->payload, stdout);
+
+ if (output)
+ fputs(output, stderr);
+}
+
+size_t parse_signature(const char *buf, size_t size)
+{
+ size_t len = 0;
+ 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 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);
- 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.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";
+
+ 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;
}
{
if (configured_signing_key)
return configured_signing_key;
- return git_committer_info(IDENT_ERROR_ON_NO_NAME|IDENT_NO_DATE);
+ 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;
- const char *args[4];
- ssize_t len;
+ struct child_process gpg = CHILD_PROCESS_INIT;
+ int ret;
size_t i, j, bottom;
+ struct strbuf gpg_status = STRBUF_INIT;
- memset(&gpg, 0, sizeof(gpg));
- gpg.argv = args;
- gpg.in = -1;
- gpg.out = -1;
- args[0] = gpg_program;
- args[1] = "-bsau";
- args[2] = signing_key;
- args[3] = NULL;
+ strvec_pushl(&gpg.args,
+ use_format->program,
+ "--status-fd=2",
+ "-bsau", signing_key,
+ NULL);
- if (start_command(&gpg))
- return error(_("could not run gpg."));
+ bottom = signature->len;
/*
* 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);
-
+ ret = pipe_command(&gpg, buffer->buf, buffer->len,
+ signature, 1024, &gpg_status, 0);
sigchain_pop(SIGPIPE);
- if (finish_command(&gpg) || !len || len < 0)
+ ret |= !strstr(gpg_status.buf, "\n[GNUPG:] SIG_CREATED ");
+ strbuf_release(&gpg_status);
+ if (ret)
return error(_("gpg failed to sign the data"));
/* Strip CR from the line endings, in case we are on Windows. */
return 0;
}
-
-/*
- * Run "gpg" to see if the payload matches the detached signature.
- * gpg_output, when set, receives the diagnostic 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 child_process gpg;
- const char *args_gpg[] = {NULL, "--verify", "FILE", "-", NULL};
- char path[PATH_MAX];
- int fd, ret;
-
- 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);
-
- memset(&gpg, 0, sizeof(gpg));
- gpg.argv = args_gpg;
- gpg.in = -1;
- if (gpg_output)
- gpg.err = -1;
- args_gpg[2] = 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);
- ret = finish_command(&gpg);
-
- unlink_or_warn(path);
-
- return ret;
-}