From: "Fabian Stelzer via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: "Han-Wen Nienhuys" <hanwen@google.com>,
"Fabian Stelzer" <fs@gigacodes.de>,
"brian m. carlson" <sandals@crustytoothpaste.net>,
"Randall S. Becker" <rsbecker@nexbridge.com>,
"Bagas Sanjaya" <bagasdotme@gmail.com>,
"Hans Jerry Illikainen" <hji@dyntopia.com>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Felipe Contreras" <felipe.contreras@gmail.com>,
"Eric Sunshine" <sunshine@sunshineco.com>,
"Gwyneth Morgan" <gwymor@tilde.club>,
"Fabian Stelzer" <fs@gigacodes.de>,
"Fabian Stelzer" <fs@gigacodes.de>
Subject: [PATCH v5 2/9] ssh signing: add ssh signature format and signing using ssh keys
Date: Tue, 27 Jul 2021 13:15:37 +0000 [thread overview]
Message-ID: <f05bab16096c080891ee8f7e179eecce7f32e839.1627391744.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.1041.v5.git.git.1627391744.gitgitgadget@gmail.com>
From: Fabian Stelzer <fs@gigacodes.de>
implements the actual sign_buffer_ssh operation and move some shared
cleanup code into a strbuf function
Set gpg.format = ssh and user.signingkey to either a ssh public key
string (like from an authorized_keys file), or a ssh key file.
If the key file or the config value itself contains only a public key
then the private key needs to be available via ssh-agent.
gpg.ssh.program can be set to an alternative location of ssh-keygen.
A somewhat recent openssh version (8.2p1+) of ssh-keygen is needed for
this feature. Since only ssh-keygen is needed it can this way be
installed seperately without upgrading your system openssh packages.
Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
---
gpg-interface.c | 137 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 129 insertions(+), 8 deletions(-)
diff --git a/gpg-interface.c b/gpg-interface.c
index 31cf4ba3938..c131977b347 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -41,12 +41,20 @@ static const char *x509_sigs[] = {
NULL
};
+static const char *ssh_verify_args[] = { NULL };
+static const char *ssh_sigs[] = {
+ "-----BEGIN SSH SIGNATURE-----",
+ NULL
+};
+
static int verify_gpg_signed_buffer(struct signature_check *sigc,
struct gpg_format *fmt, const char *payload,
size_t payload_size, const char *signature,
size_t signature_size);
static int sign_buffer_gpg(struct strbuf *buffer, struct strbuf *signature,
const char *signing_key);
+static int sign_buffer_ssh(struct strbuf *buffer, struct strbuf *signature,
+ const char *signing_key);
static struct gpg_format gpg_format[] = {
{
@@ -65,6 +73,14 @@ static struct gpg_format gpg_format[] = {
.verify_signed_buffer = verify_gpg_signed_buffer,
.sign_buffer = sign_buffer_gpg,
},
+ {
+ .name = "ssh",
+ .program = "ssh-keygen",
+ .verify_args = ssh_verify_args,
+ .sigs = ssh_sigs,
+ .verify_signed_buffer = NULL, /* TODO */
+ .sign_buffer = sign_buffer_ssh
+ },
};
static struct gpg_format *use_format = &gpg_format[0];
@@ -443,6 +459,9 @@ int git_gpg_config(const char *var, const char *value, void *cb)
if (!strcmp(var, "gpg.x509.program"))
fmtname = "x509";
+ if (!strcmp(var, "gpg.ssh.program"))
+ fmtname = "ssh";
+
if (fmtname) {
fmt = get_format_by_name(fmtname);
return git_config_string(&fmt->program, var, value);
@@ -463,12 +482,30 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *sig
return use_format->sign_buffer(buffer, signature, signing_key);
}
+/*
+ * Strip CR from the line endings, in case we are on Windows.
+ * NEEDSWORK: make it trim only CRs before LFs and rename
+ */
+static void remove_cr_after(struct strbuf *buffer, size_t offset)
+{
+ size_t i, j;
+
+ for (i = j = offset; i < buffer->len; i++) {
+ if (buffer->buf[i] != '\r') {
+ if (i != j)
+ buffer->buf[j] = buffer->buf[i];
+ j++;
+ }
+ }
+ strbuf_setlen(buffer, j);
+}
+
static int sign_buffer_gpg(struct strbuf *buffer, struct strbuf *signature,
const char *signing_key)
{
struct child_process gpg = CHILD_PROCESS_INIT;
int ret;
- size_t i, j, bottom;
+ size_t bottom;
struct strbuf gpg_status = STRBUF_INIT;
strvec_pushl(&gpg.args,
@@ -494,13 +531,97 @@ static int sign_buffer_gpg(struct strbuf *buffer, struct strbuf *signature,
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);
+ remove_cr_after(signature, bottom);
return 0;
}
+
+static int sign_buffer_ssh(struct strbuf *buffer, struct strbuf *signature,
+ const char *signing_key)
+{
+ struct child_process signer = CHILD_PROCESS_INIT;
+ int ret = -1;
+ size_t bottom, keylen;
+ struct strbuf signer_stderr = STRBUF_INIT;
+ struct tempfile *key_file = NULL, *buffer_file = NULL;
+ char *ssh_signing_key_file = NULL;
+ struct strbuf ssh_signature_filename = STRBUF_INIT;
+
+ if (!signing_key || signing_key[0] == '\0')
+ return error(
+ _("user.signingkey needs to be set for ssh signing"));
+
+ if (starts_with(signing_key, "ssh-")) {
+ /* A literal ssh key */
+ key_file = mks_tempfile_t(".git_signing_key_tmpXXXXXX");
+ if (!key_file)
+ return error_errno(
+ _("could not create temporary file"));
+ keylen = strlen(signing_key);
+ if (write_in_full(key_file->fd, signing_key, keylen) < 0 ||
+ close_tempfile_gently(key_file) < 0) {
+ error_errno(_("failed writing ssh signing key to '%s'"),
+ key_file->filename.buf);
+ goto out;
+ }
+ ssh_signing_key_file = key_file->filename.buf;
+ } else {
+ /* We assume a file */
+ ssh_signing_key_file = expand_user_path(signing_key, 1);
+ }
+
+ buffer_file = mks_tempfile_t(".git_signing_buffer_tmpXXXXXX");
+ if (!buffer_file) {
+ error_errno(_("could not create temporary file"));
+ goto out;
+ }
+
+ if (write_in_full(buffer_file->fd, buffer->buf, buffer->len) < 0 ||
+ close_tempfile_gently(buffer_file) < 0) {
+ error_errno(_("failed writing ssh signing key buffer to '%s'"),
+ buffer_file->filename.buf);
+ goto out;
+ }
+
+ strvec_pushl(&signer.args, use_format->program,
+ "-Y", "sign",
+ "-n", "git",
+ "-f", ssh_signing_key_file,
+ buffer_file->filename.buf,
+ NULL);
+
+ sigchain_push(SIGPIPE, SIG_IGN);
+ ret = pipe_command(&signer, NULL, 0, NULL, 0, &signer_stderr, 0);
+ sigchain_pop(SIGPIPE);
+
+ if (ret) {
+ if (strstr(signer_stderr.buf, "usage:"))
+ error(_("ssh-keygen -Y sign is needed for ssh signing (available in openssh version 8.2p1+)"));
+
+ error("%s", signer_stderr.buf);
+ goto out;
+ }
+
+ bottom = signature->len;
+
+ strbuf_addbuf(&ssh_signature_filename, &buffer_file->filename);
+ strbuf_addstr(&ssh_signature_filename, ".sig");
+ if (strbuf_read_file(signature, ssh_signature_filename.buf, 0) < 0) {
+ error_errno(
+ _("failed reading ssh signing data buffer from '%s'"),
+ ssh_signature_filename.buf);
+ }
+ unlink_or_warn(ssh_signature_filename.buf);
+
+ /* Strip CR from the line endings, in case we are on Windows. */
+ remove_cr_after(signature, bottom);
+
+out:
+ if (key_file)
+ delete_tempfile(&key_file);
+ if (buffer_file)
+ delete_tempfile(&buffer_file);
+ strbuf_release(&signer_stderr);
+ strbuf_release(&ssh_signature_filename);
+ return ret;
+}
--
gitgitgadget
next prev parent reply other threads:[~2021-07-27 13:15 UTC|newest]
Thread overview: 153+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-06 8:19 [PATCH] Add commit & tag signing/verification via SSH keys using ssh-keygen Fabian Stelzer via GitGitGadget
2021-07-06 10:07 ` Han-Wen Nienhuys
2021-07-06 11:23 ` Fabian Stelzer
2021-07-06 14:44 ` brian m. carlson
2021-07-06 15:33 ` Fabian Stelzer
2021-07-06 15:04 ` Junio C Hamano
2021-07-06 15:45 ` Fabian Stelzer
2021-07-06 17:55 ` Junio C Hamano
2021-07-06 19:39 ` Randall S. Becker
2021-07-07 6:26 ` Bagas Sanjaya
2021-07-07 8:48 ` Fabian Stelzer
2021-07-12 12:19 ` [PATCH v2] Add commit, tag & push " Fabian Stelzer via GitGitGadget
2021-07-12 16:55 ` Ævar Arnfjörð Bjarmason
2021-07-12 20:35 ` Fabian Stelzer
2021-07-12 21:16 ` Felipe Contreras
2021-07-14 12:10 ` [PATCH v3 0/9] RFC: Add commit & tag " Fabian Stelzer via GitGitGadget
2021-07-14 12:10 ` [PATCH v3 1/9] Add commit, tag & push signing via SSH keys Fabian Stelzer via GitGitGadget
2021-07-14 18:19 ` Junio C Hamano
2021-07-14 23:57 ` Eric Sunshine
2021-07-15 8:20 ` Fabian Stelzer
2021-07-14 12:10 ` [PATCH v3 2/9] ssh signing: add documentation Fabian Stelzer via GitGitGadget
2021-07-14 20:07 ` Junio C Hamano
2021-07-15 8:48 ` Fabian Stelzer
2021-07-15 10:43 ` Bagas Sanjaya
2021-07-15 16:29 ` Junio C Hamano
2021-07-14 12:10 ` [PATCH v3 3/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-07-14 20:20 ` Junio C Hamano
2021-07-15 7:49 ` Han-Wen Nienhuys
2021-07-15 8:06 ` Fabian Stelzer
2021-07-15 8:13 ` Fabian Stelzer
2021-07-14 12:10 ` [PATCH v3 4/9] ssh signing: sign using either gpg or ssh keys Fabian Stelzer via GitGitGadget
2021-07-14 20:32 ` Junio C Hamano
2021-07-15 8:28 ` Fabian Stelzer
2021-07-14 12:10 ` [PATCH v3 5/9] ssh signing: provide a textual representation of the signing key Fabian Stelzer via GitGitGadget
2021-07-14 12:10 ` [PATCH v3 6/9] ssh signing: parse ssh-keygen output and verify signatures Fabian Stelzer via GitGitGadget
2021-07-16 0:07 ` Gwyneth Morgan
2021-07-16 7:00 ` Fabian Stelzer
2021-07-14 12:10 ` [PATCH v3 7/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-07-14 12:10 ` [PATCH v3 8/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-07-14 12:10 ` [PATCH v3 9/9] ssh signing: add more tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 1/9] ssh signing: preliminary refactoring and clean-up Fabian Stelzer via GitGitGadget
2021-07-19 23:07 ` Junio C Hamano
2021-07-19 13:33 ` [PATCH v4 2/9] ssh signing: add ssh signature format and signing using ssh keys Fabian Stelzer via GitGitGadget
2021-07-19 23:53 ` Junio C Hamano
2021-07-20 12:26 ` Fabian Stelzer
2021-07-19 13:33 ` [PATCH v4 3/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 4/9] ssh signing: provide a textual representation of the signing key Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 5/9] ssh signing: parse ssh-keygen output and verify signatures Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 6/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 7/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 8/9] ssh signing: add more tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-07-19 13:33 ` [PATCH v4 9/9] ssh signing: add documentation Fabian Stelzer via GitGitGadget
2021-07-20 0:38 ` [PATCH v4 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Junio C Hamano
2021-07-27 13:15 ` [PATCH v5 " Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 1/9] ssh signing: preliminary refactoring and clean-up Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` Fabian Stelzer via GitGitGadget [this message]
2021-07-27 13:15 ` [PATCH v5 3/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 4/9] ssh signing: provide a textual representation of the signing key Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 5/9] ssh signing: parse ssh-keygen output and verify signatures Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 6/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 7/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 8/9] ssh signing: add more tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-07-27 13:15 ` [PATCH v5 9/9] ssh signing: add documentation Fabian Stelzer via GitGitGadget
2021-07-28 19:36 ` [PATCH v6 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Fabian Stelzer via GitGitGadget
2021-07-28 19:36 ` [PATCH v6 1/9] ssh signing: preliminary refactoring and clean-up Fabian Stelzer via GitGitGadget
2021-07-28 22:32 ` Jonathan Tan
2021-07-29 0:58 ` Junio C Hamano
2021-07-29 7:44 ` Fabian Stelzer
2021-07-29 8:43 ` Fabian Stelzer
2021-07-28 19:36 ` [PATCH v6 2/9] ssh signing: add ssh signature format and signing using ssh keys Fabian Stelzer via GitGitGadget
2021-07-28 22:45 ` Jonathan Tan
2021-07-29 1:01 ` Junio C Hamano
2021-07-29 11:01 ` Fabian Stelzer
2021-07-29 19:09 ` Josh Steadmon
2021-07-29 21:25 ` Fabian Stelzer
2021-07-28 19:36 ` [PATCH v6 3/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-07-28 21:29 ` Junio C Hamano
2021-07-28 22:48 ` Jonathan Tan
2021-07-29 8:59 ` Fabian Stelzer
2021-07-29 19:09 ` Josh Steadmon
2021-07-29 19:56 ` Junio C Hamano
2021-07-29 21:21 ` Fabian Stelzer
2021-07-28 19:36 ` [PATCH v6 4/9] ssh signing: provide a textual representation of the signing key Fabian Stelzer via GitGitGadget
2021-07-28 21:34 ` Junio C Hamano
2021-07-29 8:21 ` Fabian Stelzer
2021-07-28 19:36 ` [PATCH v6 5/9] ssh signing: parse ssh-keygen output and verify signatures Fabian Stelzer via GitGitGadget
2021-07-28 21:55 ` Junio C Hamano
2021-07-29 9:12 ` Fabian Stelzer
2021-07-29 20:43 ` Junio C Hamano
2021-07-28 23:04 ` Jonathan Tan
2021-07-29 9:48 ` Fabian Stelzer
2021-07-29 13:52 ` Fabian Stelzer
2021-08-03 7:43 ` Fabian Stelzer
2021-08-03 9:33 ` Fabian Stelzer
2021-07-29 20:46 ` Junio C Hamano
2021-07-29 21:01 ` Randall S. Becker
2021-07-29 21:12 ` Fabian Stelzer
2021-07-29 21:25 ` Randall S. Becker
2021-07-29 21:28 ` Fabian Stelzer
2021-07-29 22:28 ` Randall S. Becker
2021-07-30 8:17 ` Fabian Stelzer
2021-07-30 14:26 ` Randall S. Becker
2021-07-30 14:32 ` Fabian Stelzer
2021-07-30 15:05 ` Randall S. Becker
2021-07-28 19:36 ` [PATCH v6 6/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-07-29 19:09 ` Josh Steadmon
2021-07-29 19:57 ` Junio C Hamano
2021-07-30 7:32 ` Fabian Stelzer
2021-07-28 19:36 ` [PATCH v6 7/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-07-28 19:36 ` [PATCH v6 8/9] ssh signing: add more tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-07-28 19:36 ` [PATCH v6 9/9] ssh signing: add documentation Fabian Stelzer via GitGitGadget
2021-07-29 8:19 ` [PATCH v6 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Bagas Sanjaya
2021-07-29 11:03 ` Fabian Stelzer
2021-08-03 13:45 ` [PATCH v7 " Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 1/9] ssh signing: preliminary refactoring and clean-up Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 2/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 3/9] ssh signing: add ssh key format and signing code Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 4/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 5/9] ssh signing: provide a textual signing_key_id Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 6/9] ssh signing: verify signatures using ssh-keygen Fabian Stelzer via GitGitGadget
2021-08-03 23:47 ` Junio C Hamano
2021-08-04 9:01 ` Fabian Stelzer
2021-08-04 17:32 ` Junio C Hamano
2021-08-03 13:45 ` [PATCH v7 7/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 8/9] ssh signing: tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-08-03 13:45 ` [PATCH v7 9/9] ssh signing: test that gpg fails for unkown keys Fabian Stelzer via GitGitGadget
2021-08-29 22:15 ` [PATCH v7 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Junio C Hamano
2021-08-29 23:56 ` Gwyneth Morgan
2021-08-30 10:35 ` Fabian Stelzer
2021-09-07 17:35 ` Junio C Hamano
2021-09-10 8:03 ` Fabian Stelzer
2021-09-10 18:44 ` Junio C Hamano
2021-09-10 19:49 ` Fabian Stelzer
2021-09-10 20:20 ` Carlo Arenas
2021-09-10 20:07 ` [PATCH v8 " Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 1/9] ssh signing: preliminary refactoring and clean-up Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 2/9] ssh signing: add test prereqs Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 3/9] ssh signing: add ssh key format and signing code Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 4/9] ssh signing: retrieve a default key from ssh-agent Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 5/9] ssh signing: provide a textual signing_key_id Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 6/9] ssh signing: verify signatures using ssh-keygen Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 7/9] ssh signing: duplicate t7510 tests for commits Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 8/9] ssh signing: tests for logs, tags & push certs Fabian Stelzer via GitGitGadget
2021-09-10 20:07 ` [PATCH v8 9/9] ssh signing: test that gpg fails for unknown keys Fabian Stelzer via GitGitGadget
2021-12-22 3:18 ` t7510-signed-commit.sh hangs on old gpg, regression in 1bfb57f642d (was: [PATCH v8 9/9] ssh signing: test that gpg fails for unknown keys) Ævar Arnfjörð Bjarmason
2021-12-22 10:13 ` Fabian Stelzer
2021-12-22 15:58 ` brian m. carlson
2021-12-26 22:53 ` Ævar Arnfjörð Bjarmason
2021-12-30 11:10 ` Fabian Stelzer
2021-09-10 20:23 ` [PATCH v8 0/9] ssh signing: Add commit & tag signing/verification via SSH keys using ssh-keygen Junio C Hamano
2021-09-10 20:48 ` Fabian Stelzer
2021-09-10 21:01 ` Junio C Hamano
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