Ything-RepoMirrors/libgit2
2
0
Fork 0
mirror of https://github.com/libgit2/libgit2.git synced 2026-01-25 02:56:17 +00:00
Code Issues Packages Projects Releases Wiki Activity

Set all SSH hostkey preferences that are available

Browse Source
This commit is contained in:
Eric Huss
2023-02-04 12:17:03 -08:00
committed by Edward Thomson
parent 870f69c34c
commit b7352a7058
1 changed files with 42 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

85
src/transports/ssh.c
View File

@@ -467,28 +467,26 @@ out:
return error;
}
static const char *hostkey_type_to_string(int type)
static void add_hostkey_pref_if_avail(
LIBSSH2_KNOWNHOSTS *known_hosts,
const char *hostname,
int port,
git_str *prefs,
int type,
const char *type_name)
{
switch (type) {
case LIBSSH2_KNOWNHOST_KEY_SSHRSA:
return "ssh-rsa";
case LIBSSH2_KNOWNHOST_KEY_SSHDSS:
return "ssh-dss";
#ifdef LIBSSH2_KNOWNHOST_KEY_ECDSA_256
case LIBSSH2_KNOWNHOST_KEY_ECDSA_256:
return "ecdsa-sha2-nistp256";
case LIBSSH2_KNOWNHOST_KEY_ECDSA_384:
return "ecdsa-sha2-nistp384";
case LIBSSH2_KNOWNHOST_KEY_ECDSA_521:
return "ecdsa-sha2-nistp521";
#endif
#ifdef LIBSSH2_KNOWNHOST_KEY_ED25519
case LIBSSH2_KNOWNHOST_KEY_ED25519:
return "ssh-ed25519";
#endif
}
struct libssh2_knownhost *host = NULL;
const char key = '\0';
int mask = LIBSSH2_KNOWNHOST_TYPE_PLAIN | LIBSSH2_KNOWNHOST_KEYENC_RAW | type;
int error;
return NULL;
error = libssh2_knownhost_checkp(known_hosts, hostname, port, &key, 1, mask, &host);
if (error == LIBSSH2_KNOWNHOST_CHECK_MISMATCH) {
if (git_str_len(prefs) > 0) {
git_str_putc(prefs, ',');
}
git_str_puts(prefs, type_name);
}
}
/*
@@ -496,27 +494,27 @@ static const char *hostkey_type_to_string(int type)
* look it up with a nonsense key and using that mismatch to figure out what key
* we do have stored for the host.
*
* Returns the string to pass to libssh2_session_method_pref or NULL if we were
* unable to find anything or an error happened.
* Populates prefs with the string to pass to libssh2_session_method_pref.
*/
static const char *find_hostkey_preference(LIBSSH2_KNOWNHOSTS *known_hosts, const char *hostname, int port)
static void find_hostkey_preference(
LIBSSH2_KNOWNHOSTS *known_hosts,
const char *hostname,
int port,
git_str *prefs)
{
struct libssh2_knownhost *host = NULL;
/* Specify no key type so we don't filter on that */
int type = LIBSSH2_KNOWNHOST_TYPE_PLAIN | LIBSSH2_KNOWNHOST_KEYENC_RAW;
const char key = '\0';
int error;
/*
* In case of mismatch, we can find the type of key from known_hosts in
* the returned host's information as it means that an entry was found
* but our nonsense key obviously didn't match.
* The order here is important as it indicates the priority of what will
* be preferred.
*/
error = libssh2_knownhost_checkp(known_hosts, hostname, port, &key, 1, type, &host);
if (error == LIBSSH2_KNOWNHOST_CHECK_MISMATCH)
return hostkey_type_to_string(host->typemask & LIBSSH2_KNOWNHOST_KEY_MASK);
return NULL;
#ifdef LIBSSH2_KNOWNHOST_KEY_ED25519
add_hostkey_pref_if_avail(known_hosts, hostname, port, prefs, LIBSSH2_KNOWNHOST_KEY_ED25519, "ssh-ed25519");
#endif
#ifdef LIBSSH2_KNOWNHOST_KEY_ECDSA_256
add_hostkey_pref_if_avail(known_hosts, hostname, port, prefs, LIBSSH2_KNOWNHOST_KEY_ECDSA_256, "ecdsa-sha2-nistp256");
add_hostkey_pref_if_avail(known_hosts, hostname, port, prefs, LIBSSH2_KNOWNHOST_KEY_ECDSA_384, "ecdsa-sha2-nistp384");
add_hostkey_pref_if_avail(known_hosts, hostname, port, prefs, LIBSSH2_KNOWNHOST_KEY_ECDSA_521, "ecdsa-sha2-nistp521");
#endif
add_hostkey_pref_if_avail(known_hosts, hostname, port, prefs, LIBSSH2_KNOWNHOST_KEY_SSHRSA, "ssh-rsa");
}
static int _git_ssh_session_create(
@@ -526,11 +524,11 @@ static int _git_ssh_session_create(
int port,
git_stream *io)
{
int rc = 0;
git_socket_stream *socket = GIT_CONTAINER_OF(io, git_socket_stream, parent);
LIBSSH2_SESSION *s;
LIBSSH2_KNOWNHOSTS *known_hosts;
git_socket_stream *socket = GIT_CONTAINER_OF(io, git_socket_stream, parent);
const char *keytype = NULL;
git_str prefs = GIT_STR_INIT;
int rc = 0;
GIT_ASSERT_ARG(session);
GIT_ASSERT_ARG(hosts);
@@ -547,16 +545,17 @@ static int _git_ssh_session_create(
return -1;
}
if ((keytype = find_hostkey_preference(known_hosts, hostname, port)) != NULL) {
find_hostkey_preference(known_hosts, hostname, port, &prefs);
if (git_str_len(&prefs) > 0) {
do {
rc = libssh2_session_method_pref(s, LIBSSH2_METHOD_HOSTKEY, keytype);
rc = libssh2_session_method_pref(s, LIBSSH2_METHOD_HOSTKEY, git_str_cstr(&prefs));
} while (LIBSSH2_ERROR_EAGAIN == rc || LIBSSH2_ERROR_TIMEOUT == rc);
if (rc != LIBSSH2_ERROR_NONE) {
ssh_error(s, "failed to set hostkey preference");
goto on_error;
}
}
git_str_dispose(&prefs);
do {
rc = libssh2_session_handshake(s, socket->s);