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-rw-r--r--tools/plink/ssh.c166
1 files changed, 118 insertions, 48 deletions
diff --git a/tools/plink/ssh.c b/tools/plink/ssh.c
index 893321e2b..d395d7b5c 100644
--- a/tools/plink/ssh.c
+++ b/tools/plink/ssh.c
@@ -3677,6 +3677,59 @@ static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
sfree(error);
}
+int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint,
+ const struct ssh_signkey *ssh2keytype,
+ void *ssh2keydata)
+{
+ if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) {
+ return -1; /* no manual keys configured */
+ }
+
+ if (fingerprint) {
+ /*
+ * The fingerprint string we've been given will have things
+ * like 'ssh-rsa 2048' at the front of it. Strip those off and
+ * narrow down to just the colon-separated hex block at the
+ * end of the string.
+ */
+ const char *p = strrchr(fingerprint, ' ');
+ fingerprint = p ? p+1 : fingerprint;
+ /* Quick sanity checks, including making sure it's in lowercase */
+ assert(strlen(fingerprint) == 16*3 - 1);
+ assert(fingerprint[2] == ':');
+ assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0);
+
+ if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
+ fingerprint))
+ return 1; /* success */
+ }
+
+ if (ssh2keydata) {
+ /*
+ * Construct the base64-encoded public key blob and see if
+ * that's listed.
+ */
+ unsigned char *binblob;
+ char *base64blob;
+ int binlen, atoms, i;
+ binblob = ssh2keytype->public_blob(ssh2keydata, &binlen);
+ atoms = (binlen + 2) / 3;
+ base64blob = snewn(atoms * 4 + 1, char);
+ for (i = 0; i < atoms; i++)
+ base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i);
+ base64blob[atoms * 4] = '\0';
+ sfree(binblob);
+ if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys,
+ base64blob)) {
+ sfree(base64blob);
+ return 1; /* success */
+ }
+ sfree(base64blob);
+ }
+
+ return 0;
+}
+
/*
* Handle the key exchange and user authentication phases.
*/
@@ -3800,29 +3853,36 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
rsastr_fmt(keystr, &s->hostkey);
rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- "rsa", keystr, fingerprint,
- ssh_dialog_callback, ssh);
- sfree(keystr);
- if (s->dlgret < 0) {
- do {
- crReturn(0);
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStop(0);
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
+ /* First check against manually configured host keys. */
+ s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL);
+ if (s->dlgret == 0) { /* did not match */
+ bombout(("Host key did not appear in manually configured list"));
+ crStop(0);
+ } else if (s->dlgret < 0) { /* none configured; use standard handling */
+ ssh_set_frozen(ssh, 1);
+ s->dlgret = verify_ssh_host_key(ssh->frontend,
+ ssh->savedhost, ssh->savedport,
+ "rsa", keystr, fingerprint,
+ ssh_dialog_callback, ssh);
+ sfree(keystr);
+ if (s->dlgret < 0) {
+ do {
+ crReturn(0);
+ if (pktin) {
+ bombout(("Unexpected data from server while waiting"
+ " for user host key response"));
+ crStop(0);
+ }
+ } while (pktin || inlen > 0);
+ s->dlgret = ssh->user_response;
+ }
+ ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification",
- NULL, 0, TRUE);
- crStop(0);
+ if (s->dlgret == 0) {
+ ssh_disconnect(ssh, "User aborted at host key verification",
+ NULL, 0, TRUE);
+ crStop(0);
+ }
}
}
@@ -6721,31 +6781,39 @@ static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
* checked the signature of the exchange hash.)
*/
s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
- ssh_set_frozen(ssh, 1);
- s->dlgret = verify_ssh_host_key(ssh->frontend,
- ssh->savedhost, ssh->savedport,
- ssh->hostkey->keytype, s->keystr,
- s->fingerprint,
- ssh_dialog_callback, ssh);
- if (s->dlgret < 0) {
- do {
- crReturnV;
- if (pktin) {
- bombout(("Unexpected data from server while waiting"
- " for user host key response"));
- crStopV;
- }
- } while (pktin || inlen > 0);
- s->dlgret = ssh->user_response;
- }
- ssh_set_frozen(ssh, 0);
- if (s->dlgret == 0) {
- ssh_disconnect(ssh, "User aborted at host key verification", NULL,
- 0, TRUE);
- crStopV;
- }
logevent("Host key fingerprint is:");
logevent(s->fingerprint);
+ /* First check against manually configured host keys. */
+ s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint,
+ ssh->hostkey, s->hkey);
+ if (s->dlgret == 0) { /* did not match */
+ bombout(("Host key did not appear in manually configured list"));
+ crStopV;
+ } else if (s->dlgret < 0) { /* none configured; use standard handling */
+ ssh_set_frozen(ssh, 1);
+ s->dlgret = verify_ssh_host_key(ssh->frontend,
+ ssh->savedhost, ssh->savedport,
+ ssh->hostkey->keytype, s->keystr,
+ s->fingerprint,
+ ssh_dialog_callback, ssh);
+ if (s->dlgret < 0) {
+ do {
+ crReturnV;
+ if (pktin) {
+ bombout(("Unexpected data from server while waiting"
+ " for user host key response"));
+ crStopV;
+ }
+ } while (pktin || inlen > 0);
+ s->dlgret = ssh->user_response;
+ }
+ ssh_set_frozen(ssh, 0);
+ if (s->dlgret == 0) {
+ ssh_disconnect(ssh, "Aborted at host key verification", NULL,
+ 0, TRUE);
+ crStopV;
+ }
+ }
sfree(s->fingerprint);
/*
* Save this host key, to check against the one presented in
@@ -10557,11 +10625,13 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle,
ssh->gsslibs = NULL;
#endif
+ random_ref(); /* do this now - may be needed by sharing setup code */
+
p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
- if (p != NULL)
+ if (p != NULL) {
+ random_unref();
return p;
-
- random_ref();
+ }
return NULL;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-02 08:59:54 +0000