int
mm_answer_rsa_keyallowed(int sock, struct sshbuf *m)
{
BIGNUM *client_n;
struct sshkey *key = NULL;
u_char *blob = NULL;
size_t blen = 0;
int r, allowed = 0;
debug3("%s entering", __func__);
auth_method = "rsa";
if (options.rsa_authentication && authctxt->valid) {
if ((client_n = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
if ((r = sshbuf_get_bignum2(m, client_n)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
BN_clear_free(client_n);
}
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, allowed)) != 0 ||
(r = sshbuf_put_u32(m, forced_command != NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
/* clear temporarily storage (used by generate challenge) */
monitor_reset_key_state();
if (allowed && key != NULL) {
key->type = KEY_RSA; /* cheat for key_to_blob */
if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
fatal("%s: key_to_blob failed: %s",
__func__, ssh_err(r));
if ((r = sshbuf_put_string(m, blob, blen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = blen;
key_blobtype = MM_RSAUSERKEY;
}
if (key != NULL)
sshkey_free(key);
mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
return (0);
}
/*
* Performs the RSA authentication dialog with the client. This returns
* 0 if the client could not be authenticated, and 1 if authentication was
* successful. This may exit if there is a serious protocol violation.
*/
int
auth_rsa(Authctxt *authctxt, BIGNUM *client_n)
{
struct ssh *ssh = active_state;
struct sshkey *key;
char *fp;
struct passwd *pw = authctxt->pw;
/* no user given */
if (!authctxt->valid)
return 0;
if (!PRIVSEP(auth_rsa_key_allowed(pw, client_n, &key))) {
auth_clear_options();
return (0);
}
/* Perform the challenge-response dialog for this key. */
if (!auth_rsa_challenge_dialog(key)) {
/* Wrong response. */
verbose("Wrong response to RSA authentication challenge.");
ssh_packet_send_debug(ssh,
"Wrong response to RSA authentication challenge.");
/*
* Break out of the loop. Otherwise we might send
* another challenge and break the protocol.
*/
sshkey_free(key);
return (0);
}
/*
* Correct response. The client has been successfully
* authenticated. Note that we have not yet processed the
* options; this will be reset if the options cause the
* authentication to be rejected.
*/
fp = sshkey_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
verbose("Found matching %s key: %s",
sshkey_type(key), fp);
xfree(fp);
sshkey_free(key);
ssh_packet_send_debug(ssh, "RSA authentication accepted.");
return (1);
}
int
mm_answer_rsa_keyallowed(int socket, Buffer *m)
{
BIGNUM *client_n;
Key *key = NULL;
u_char *blob = NULL;
u_int blen = 0;
int allowed = 0;
debug3("%s entering", __func__);
if (options.rsa_authentication && authctxt->valid) {
if ((client_n = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
buffer_get_bignum2(m, client_n);
allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
BN_clear_free(client_n);
}
buffer_clear(m);
buffer_put_int(m, allowed);
/* clear temporarily storage (used by generate challenge) */
monitor_reset_key_state();
if (allowed && key != NULL) {
key->type = KEY_RSA; /* cheat for key_to_blob */
if (key_to_blob(key, &blob, &blen) == 0)
fatal("%s: key_to_blob failed", __func__);
buffer_put_string(m, blob, blen);
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = blen;
key_blobtype = MM_RSAUSERKEY;
key_free(key);
}
mm_append_debug(m);
mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
return (0);
}
/*
* Performs the RSA authentication dialog with the client. This returns
* 0 if the client could not be authenticated, and 1 if authentication was
* successful. This may exit if there is a serious protocol violation.
*/
int
auth_rsa(Authctxt *authctxt, BIGNUM *client_n)
{
Key *key;
struct passwd *pw = authctxt->pw;
/* no user given */
if (!authctxt->valid)
return 0;
if (!PRIVSEP(auth_rsa_key_allowed(pw, client_n, &key))) {
auth_clear_options();
return (0);
}
/* Perform the challenge-response dialog for this key. */
if (!auth_rsa_challenge_dialog(key)) {
/* Wrong response. */
verbose("Wrong response to RSA authentication challenge.");
packet_send_debug("Wrong response to RSA authentication challenge.");
/*
* Break out of the loop. Otherwise we might send
* another challenge and break the protocol.
*/
key_free(key);
return (0);
}
/*
* Correct response. The client has been successfully
* authenticated. Note that we have not yet processed the
* options; this will be reset if the options cause the
* authentication to be rejected.
*/
pubkey_auth_info(authctxt, key, NULL);
packet_send_debug("RSA authentication accepted.");
return (1);
}
