+/* $OpenBSD: sshconnect1.c,v 1.70 2006/11/06 21:25:28 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- * Created: Sat Mar 18 22:15:47 1995 ylo
* Code to connect to a remote host, and to perform the client side of the
* login (authentication) dialog.
*
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect1.c,v 1.2 2000/05/04 22:38:00 markus Exp $");
+
+#include <sys/types.h>
+#include <sys/socket.h>
#include <openssl/bn.h>
-#include <openssl/dsa.h>
-#include <openssl/rsa.h>
-#include <openssl/evp.h>
+#include <openssl/md5.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <pwd.h>
#include "xmalloc.h"
-#include "rsa.h"
#include "ssh.h"
+#include "ssh1.h"
+#include "rsa.h"
#include "buffer.h"
#include "packet.h"
-#include "authfd.h"
+#include "key.h"
#include "cipher.h"
-#include "mpaux.h"
+#include "kex.h"
#include "uidswap.h"
+#include "log.h"
#include "readconf.h"
-#include "key.h"
+#include "authfd.h"
#include "sshconnect.h"
#include "authfile.h"
+#include "misc.h"
+#include "canohost.h"
+#include "hostfile.h"
+#include "auth.h"
/* Session id for the current session. */
-unsigned char session_id[16];
-unsigned int supported_authentications = 0;
+u_char session_id[16];
+u_int supported_authentications = 0;
extern Options options;
extern char *__progname;
* Checks if the user has an authentication agent, and if so, tries to
* authenticate using the agent.
*/
-int
-try_agent_authentication()
+static int
+try_agent_authentication(void)
{
- int status, type;
+ int type;
char *comment;
AuthenticationConnection *auth;
- unsigned char response[16];
- unsigned int i;
- BIGNUM *e, *n, *challenge;
+ u_char response[16];
+ u_int i;
+ Key *key;
+ BIGNUM *challenge;
/* Get connection to the agent. */
auth = ssh_get_authentication_connection();
if (!auth)
return 0;
- e = BN_new();
- n = BN_new();
- challenge = BN_new();
-
+ if ((challenge = BN_new()) == NULL)
+ fatal("try_agent_authentication: BN_new failed");
/* Loop through identities served by the agent. */
- for (status = ssh_get_first_identity(auth, e, n, &comment);
- status;
- status = ssh_get_next_identity(auth, e, n, &comment)) {
- int plen, clen;
+ for (key = ssh_get_first_identity(auth, &comment, 1);
+ key != NULL;
+ key = ssh_get_next_identity(auth, &comment, 1)) {
/* Try this identity. */
debug("Trying RSA authentication via agent with '%.100s'", comment);
/* Tell the server that we are willing to authenticate using this key. */
packet_start(SSH_CMSG_AUTH_RSA);
- packet_put_bignum(n);
+ packet_put_bignum(key->rsa->n);
packet_send();
packet_write_wait();
/* Wait for server's response. */
- type = packet_read(&plen);
+ type = packet_read();
- /* The server sends failure if it doesn\'t like our key or
+ /* The server sends failure if it doesn't like our key or
does not support RSA authentication. */
if (type == SSH_SMSG_FAILURE) {
debug("Server refused our key.");
+ key_free(key);
continue;
}
/* Otherwise it should have sent a challenge. */
packet_disconnect("Protocol error during RSA authentication: %d",
type);
- packet_get_bignum(challenge, &clen);
-
- packet_integrity_check(plen, clen, type);
+ packet_get_bignum(challenge);
+ packet_check_eom();
debug("Received RSA challenge from server.");
/* Ask the agent to decrypt the challenge. */
- if (!ssh_decrypt_challenge(auth, e, n, challenge,
- session_id, 1, response)) {
- /* The agent failed to authenticate this identifier although it
- advertised it supports this. Just return a wrong value. */
- log("Authentication agent failed to decrypt challenge.");
+ if (!ssh_decrypt_challenge(auth, key, challenge, session_id, 1, response)) {
+ /*
+ * The agent failed to authenticate this identifier
+ * although it advertised it supports this. Just
+ * return a wrong value.
+ */
+ logit("Authentication agent failed to decrypt challenge.");
memset(response, 0, sizeof(response));
}
+ key_free(key);
debug("Sending response to RSA challenge.");
/* Send the decrypted challenge back to the server. */
packet_write_wait();
/* Wait for response from the server. */
- type = packet_read(&plen);
+ type = packet_read();
/* The server returns success if it accepted the authentication. */
if (type == SSH_SMSG_SUCCESS) {
- debug("RSA authentication accepted by server.");
- BN_clear_free(e);
- BN_clear_free(n);
+ ssh_close_authentication_connection(auth);
BN_clear_free(challenge);
+ debug("RSA authentication accepted by server.");
return 1;
}
/* Otherwise it should return failure. */
packet_disconnect("Protocol error waiting RSA auth response: %d",
type);
}
-
- BN_clear_free(e);
- BN_clear_free(n);
+ ssh_close_authentication_connection(auth);
BN_clear_free(challenge);
-
debug("RSA authentication using agent refused.");
return 0;
}
* Computes the proper response to a RSA challenge, and sends the response to
* the server.
*/
-void
+static void
respond_to_rsa_challenge(BIGNUM * challenge, RSA * prv)
{
- unsigned char buf[32], response[16];
+ u_char buf[32], response[16];
MD5_CTX md;
int i, len;
/* Decrypt the challenge using the private key. */
- rsa_private_decrypt(challenge, challenge, prv);
+ /* XXX think about Bleichenbacher, too */
+ if (rsa_private_decrypt(challenge, challenge, prv) <= 0)
+ packet_disconnect(
+ "respond_to_rsa_challenge: rsa_private_decrypt failed");
/* Compute the response. */
/* The response is MD5 of decrypted challenge plus session id. */
len = BN_num_bytes(challenge);
- if (len <= 0 || len > sizeof(buf))
- packet_disconnect("respond_to_rsa_challenge: bad challenge length %d",
- len);
+ if (len <= 0 || (u_int)len > sizeof(buf))
+ packet_disconnect(
+ "respond_to_rsa_challenge: bad challenge length %d", len);
memset(buf, 0, sizeof(buf));
BN_bn2bin(challenge, buf + sizeof(buf) - len);
* Checks if the user has authentication file, and if so, tries to authenticate
* the user using it.
*/
-int
-try_rsa_authentication(const char *authfile)
+static int
+try_rsa_authentication(int idx)
{
BIGNUM *challenge;
- Key *public;
- Key *private;
- char *passphrase, *comment;
- int type, i;
- int plen, clen;
+ Key *public, *private;
+ char buf[300], *passphrase, *comment, *authfile;
+ int i, perm_ok = 1, type, quit;
+
+ public = options.identity_keys[idx];
+ authfile = options.identity_files[idx];
+ comment = xstrdup(authfile);
- /* Try to load identification for the authentication key. */
- public = key_new(KEY_RSA);
- if (!load_public_key(authfile, public, &comment)) {
- key_free(public);
- /* Could not load it. Fail. */
- return 0;
- }
debug("Trying RSA authentication with key '%.100s'", comment);
/* Tell the server that we are willing to authenticate using this key. */
packet_send();
packet_write_wait();
- /* We no longer need the public key. */
- key_free(public);
-
/* Wait for server's response. */
- type = packet_read(&plen);
+ type = packet_read();
/*
- * The server responds with failure if it doesn\'t like our key or
- * doesn\'t support RSA authentication.
+ * The server responds with failure if it doesn't like our key or
+ * doesn't support RSA authentication.
*/
if (type == SSH_SMSG_FAILURE) {
debug("Server refused our key.");
packet_disconnect("Protocol error during RSA authentication: %d", type);
/* Get the challenge from the packet. */
- challenge = BN_new();
- packet_get_bignum(challenge, &clen);
-
- packet_integrity_check(plen, clen, type);
+ if ((challenge = BN_new()) == NULL)
+ fatal("try_rsa_authentication: BN_new failed");
+ packet_get_bignum(challenge);
+ packet_check_eom();
debug("Received RSA challenge from server.");
- private = key_new(KEY_RSA);
/*
- * Load the private key. Try first with empty passphrase; if it
+ * If the key is not stored in external hardware, we have to
+ * load the private key. Try first with empty passphrase; if it
* fails, ask for a passphrase.
*/
- if (!load_private_key(authfile, "", private, NULL)) {
- char buf[300];
- snprintf(buf, sizeof buf, "Enter passphrase for RSA key '%.100s': ",
- comment);
- if (!options.batch_mode)
+ if (public->flags & KEY_FLAG_EXT)
+ private = public;
+ else
+ private = key_load_private_type(KEY_RSA1, authfile, "", NULL,
+ &perm_ok);
+ if (private == NULL && !options.batch_mode && perm_ok) {
+ snprintf(buf, sizeof(buf),
+ "Enter passphrase for RSA key '%.100s': ", comment);
+ for (i = 0; i < options.number_of_password_prompts; i++) {
passphrase = read_passphrase(buf, 0);
- else {
- debug("Will not query passphrase for %.100s in batch mode.",
- comment);
- passphrase = xstrdup("");
- }
-
- /* Load the authentication file using the pasphrase. */
- if (!load_private_key(authfile, passphrase, private, NULL)) {
+ if (strcmp(passphrase, "") != 0) {
+ private = key_load_private_type(KEY_RSA1,
+ authfile, passphrase, NULL, NULL);
+ quit = 0;
+ } else {
+ debug2("no passphrase given, try next key");
+ quit = 1;
+ }
memset(passphrase, 0, strlen(passphrase));
xfree(passphrase);
- error("Bad passphrase.");
-
- /* Send a dummy response packet to avoid protocol error. */
- packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
- for (i = 0; i < 16; i++)
- packet_put_char(0);
- packet_send();
- packet_write_wait();
-
- /* Expect the server to reject it... */
- packet_read_expect(&plen, SSH_SMSG_FAILURE);
- xfree(comment);
- return 0;
+ if (private != NULL || quit)
+ break;
+ debug2("bad passphrase given, try again...");
}
- /* Destroy the passphrase. */
- memset(passphrase, 0, strlen(passphrase));
- xfree(passphrase);
}
/* We no longer need the comment. */
xfree(comment);
+ if (private == NULL) {
+ if (!options.batch_mode && perm_ok)
+ error("Bad passphrase.");
+
+ /* Send a dummy response packet to avoid protocol error. */
+ packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
+ for (i = 0; i < 16; i++)
+ packet_put_char(0);
+ packet_send();
+ packet_write_wait();
+
+ /* Expect the server to reject it... */
+ packet_read_expect(SSH_SMSG_FAILURE);
+ BN_clear_free(challenge);
+ return 0;
+ }
+
/* Compute and send a response to the challenge. */
respond_to_rsa_challenge(challenge, private->rsa);
- /* Destroy the private key. */
- key_free(private);
+ /* Destroy the private key unless it in external hardware. */
+ if (!(private->flags & KEY_FLAG_EXT))
+ key_free(private);
/* We no longer need the challenge. */
BN_clear_free(challenge);
/* Wait for response from the server. */
- type = packet_read(&plen);
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS) {
debug("RSA authentication accepted by server.");
return 1;
* Tries to authenticate the user using combined rhosts or /etc/hosts.equiv
* authentication and RSA host authentication.
*/
-int
-try_rhosts_rsa_authentication(const char *local_user, RSA * host_key)
+static int
+try_rhosts_rsa_authentication(const char *local_user, Key * host_key)
{
int type;
BIGNUM *challenge;
- int plen, clen;
debug("Trying rhosts or /etc/hosts.equiv with RSA host authentication.");
/* Tell the server that we are willing to authenticate using this key. */
packet_start(SSH_CMSG_AUTH_RHOSTS_RSA);
- packet_put_string(local_user, strlen(local_user));
- packet_put_int(BN_num_bits(host_key->n));
- packet_put_bignum(host_key->e);
- packet_put_bignum(host_key->n);
+ packet_put_cstring(local_user);
+ packet_put_int(BN_num_bits(host_key->rsa->n));
+ packet_put_bignum(host_key->rsa->e);
+ packet_put_bignum(host_key->rsa->n);
packet_send();
packet_write_wait();
/* Wait for server's response. */
- type = packet_read(&plen);
+ type = packet_read();
/* The server responds with failure if it doesn't admit our
.rhosts authentication or doesn't know our host key. */
packet_disconnect("Protocol error during RSA authentication: %d", type);
/* Get the challenge from the packet. */
- challenge = BN_new();
- packet_get_bignum(challenge, &clen);
-
- packet_integrity_check(plen, clen, type);
+ if ((challenge = BN_new()) == NULL)
+ fatal("try_rhosts_rsa_authentication: BN_new failed");
+ packet_get_bignum(challenge);
+ packet_check_eom();
debug("Received RSA challenge for host key from server.");
/* Compute a response to the challenge. */
- respond_to_rsa_challenge(challenge, host_key);
+ respond_to_rsa_challenge(challenge, host_key->rsa);
/* We no longer need the challenge. */
BN_clear_free(challenge);
/* Wait for response from the server. */
- type = packet_read(&plen);
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS) {
debug("Rhosts or /etc/hosts.equiv with RSA host authentication accepted by server.");
return 1;
return 0;
}
-#ifdef KRB4
-int
-try_kerberos_authentication()
-{
- KTEXT_ST auth; /* Kerberos data */
- char *reply;
- char inst[INST_SZ];
- char *realm;
- CREDENTIALS cred;
- int r, type, plen;
- socklen_t slen;
- Key_schedule schedule;
- u_long checksum, cksum;
- MSG_DAT msg_data;
- struct sockaddr_in local, foreign;
- struct stat st;
-
- /* Don't do anything if we don't have any tickets. */
- if (stat(tkt_string(), &st) < 0)
- return 0;
-
- strncpy(inst, (char *) krb_get_phost(get_canonical_hostname()), INST_SZ);
-
- realm = (char *) krb_realmofhost(get_canonical_hostname());
- if (!realm) {
- debug("Kerberos V4: no realm for %s", get_canonical_hostname());
- return 0;
- }
- /* This can really be anything. */
- checksum = (u_long) getpid();
-
- r = krb_mk_req(&auth, KRB4_SERVICE_NAME, inst, realm, checksum);
- if (r != KSUCCESS) {
- debug("Kerberos V4 krb_mk_req failed: %s", krb_err_txt[r]);
- return 0;
- }
- /* Get session key to decrypt the server's reply with. */
- r = krb_get_cred(KRB4_SERVICE_NAME, inst, realm, &cred);
- if (r != KSUCCESS) {
- debug("get_cred failed: %s", krb_err_txt[r]);
- return 0;
- }
- des_key_sched((des_cblock *) cred.session, schedule);
-
- /* Send authentication info to server. */
- packet_start(SSH_CMSG_AUTH_KERBEROS);
- packet_put_string((char *) auth.dat, auth.length);
- packet_send();
- packet_write_wait();
-
- /* Zero the buffer. */
- (void) memset(auth.dat, 0, MAX_KTXT_LEN);
-
- slen = sizeof(local);
- memset(&local, 0, sizeof(local));
- if (getsockname(packet_get_connection_in(),
- (struct sockaddr *) & local, &slen) < 0)
- debug("getsockname failed: %s", strerror(errno));
-
- slen = sizeof(foreign);
- memset(&foreign, 0, sizeof(foreign));
- if (getpeername(packet_get_connection_in(),
- (struct sockaddr *) & foreign, &slen) < 0) {
- debug("getpeername failed: %s", strerror(errno));
- fatal_cleanup();
- }
- /* Get server reply. */
- type = packet_read(&plen);
- switch (type) {
- case SSH_SMSG_FAILURE:
- /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
- debug("Kerberos V4 authentication failed.");
- return 0;
- break;
-
- case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
- /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
- debug("Kerberos V4 authentication accepted.");
-
- /* Get server's response. */
- reply = packet_get_string((unsigned int *) &auth.length);
- memcpy(auth.dat, reply, auth.length);
- xfree(reply);
-
- packet_integrity_check(plen, 4 + auth.length, type);
-
- /*
- * If his response isn't properly encrypted with the session
- * key, and the decrypted checksum fails to match, he's
- * bogus. Bail out.
- */
- r = krb_rd_priv(auth.dat, auth.length, schedule, &cred.session,
- &foreign, &local, &msg_data);
- if (r != KSUCCESS) {
- debug("Kerberos V4 krb_rd_priv failed: %s", krb_err_txt[r]);
- packet_disconnect("Kerberos V4 challenge failed!");
- }
- /* Fetch the (incremented) checksum that we supplied in the request. */
- (void) memcpy((char *) &cksum, (char *) msg_data.app_data, sizeof(cksum));
- cksum = ntohl(cksum);
-
- /* If it matches, we're golden. */
- if (cksum == checksum + 1) {
- debug("Kerberos V4 challenge successful.");
- return 1;
- } else
- packet_disconnect("Kerberos V4 challenge failed!");
- break;
-
- default:
- packet_disconnect("Protocol error on Kerberos V4 response: %d", type);
- }
- return 0;
-}
-
-#endif /* KRB4 */
-
-#ifdef AFS
-int
-send_kerberos_tgt()
-{
- CREDENTIALS *creds;
- char pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ];
- int r, type, plen;
- char buffer[8192];
- struct stat st;
-
- /* Don't do anything if we don't have any tickets. */
- if (stat(tkt_string(), &st) < 0)
- return 0;
-
- creds = xmalloc(sizeof(*creds));
-
- if ((r = krb_get_tf_fullname(TKT_FILE, pname, pinst, prealm)) != KSUCCESS) {
- debug("Kerberos V4 tf_fullname failed: %s", krb_err_txt[r]);
- return 0;
- }
- if ((r = krb_get_cred("krbtgt", prealm, prealm, creds)) != GC_OK) {
- debug("Kerberos V4 get_cred failed: %s", krb_err_txt[r]);
- return 0;
- }
- if (time(0) > krb_life_to_time(creds->issue_date, creds->lifetime)) {
- debug("Kerberos V4 ticket expired: %s", TKT_FILE);
- return 0;
- }
- creds_to_radix(creds, (unsigned char *)buffer, sizeof buffer);
- xfree(creds);
-
- packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
- packet_put_string(buffer, strlen(buffer));
- packet_send();
- packet_write_wait();
-
- type = packet_read(&plen);
-
- if (type == SSH_SMSG_FAILURE)
- debug("Kerberos TGT for realm %s rejected.", prealm);
- else if (type != SSH_SMSG_SUCCESS)
- packet_disconnect("Protocol error on Kerberos TGT response: %d", type);
-
- return 1;
-}
-
-void
-send_afs_tokens(void)
-{
- CREDENTIALS creds;
- struct ViceIoctl parms;
- struct ClearToken ct;
- int i, type, len, plen;
- char buf[2048], *p, *server_cell;
- char buffer[8192];
-
- /* Move over ktc_GetToken, here's something leaner. */
- for (i = 0; i < 100; i++) { /* just in case */
- parms.in = (char *) &i;
- parms.in_size = sizeof(i);
- parms.out = buf;
- parms.out_size = sizeof(buf);
- if (k_pioctl(0, VIOCGETTOK, &parms, 0) != 0)
- break;
- p = buf;
-
- /* Get secret token. */
- memcpy(&creds.ticket_st.length, p, sizeof(unsigned int));
- if (creds.ticket_st.length > MAX_KTXT_LEN)
- break;
- p += sizeof(unsigned int);
- memcpy(creds.ticket_st.dat, p, creds.ticket_st.length);
- p += creds.ticket_st.length;
-
- /* Get clear token. */
- memcpy(&len, p, sizeof(len));
- if (len != sizeof(struct ClearToken))
- break;
- p += sizeof(len);
- memcpy(&ct, p, len);
- p += len;
- p += sizeof(len); /* primary flag */
- server_cell = p;
-
- /* Flesh out our credentials. */
- strlcpy(creds.service, "afs", sizeof creds.service);
- creds.instance[0] = '\0';
- strlcpy(creds.realm, server_cell, REALM_SZ);
- memcpy(creds.session, ct.HandShakeKey, DES_KEY_SZ);
- creds.issue_date = ct.BeginTimestamp;
- creds.lifetime = krb_time_to_life(creds.issue_date, ct.EndTimestamp);
- creds.kvno = ct.AuthHandle;
- snprintf(creds.pname, sizeof(creds.pname), "AFS ID %d", ct.ViceId);
- creds.pinst[0] = '\0';
-
- /* Encode token, ship it off. */
- if (creds_to_radix(&creds, (unsigned char*) buffer, sizeof buffer) <= 0)
- break;
- packet_start(SSH_CMSG_HAVE_AFS_TOKEN);
- packet_put_string(buffer, strlen(buffer));
- packet_send();
- packet_write_wait();
-
- /* Roger, Roger. Clearance, Clarence. What's your vector,
- Victor? */
- type = packet_read(&plen);
-
- if (type == SSH_SMSG_FAILURE)
- debug("AFS token for cell %s rejected.", server_cell);
- else if (type != SSH_SMSG_SUCCESS)
- packet_disconnect("Protocol error on AFS token response: %d", type);
- }
-}
-
-#endif /* AFS */
-
/*
* Tries to authenticate with any string-based challenge/response system.
* Note that the client code is not tied to s/key or TIS.
*/
-int
-try_skey_authentication()
+static int
+try_challenge_response_authentication(void)
{
int type, i;
- int payload_len;
- unsigned int clen;
+ u_int clen;
+ char prompt[1024];
char *challenge, *response;
- debug("Doing skey authentication.");
+ debug("Doing challenge response authentication.");
- /* request a challenge */
- packet_start(SSH_CMSG_AUTH_TIS);
- packet_send();
- packet_write_wait();
-
- type = packet_read(&payload_len);
- if (type != SSH_SMSG_FAILURE &&
- type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
- packet_disconnect("Protocol error: got %d in response "
- "to skey-auth", type);
- }
- if (type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
- debug("No challenge for skey authentication.");
- return 0;
- }
- challenge = packet_get_string(&clen);
- packet_integrity_check(payload_len, (4 + clen), type);
- if (options.cipher == SSH_CIPHER_NONE)
- log("WARNING: Encryption is disabled! "
- "Reponse will be transmitted in clear text.");
- fprintf(stderr, "%s\n", challenge);
- xfree(challenge);
- fflush(stderr);
for (i = 0; i < options.number_of_password_prompts; i++) {
+ /* request a challenge */
+ packet_start(SSH_CMSG_AUTH_TIS);
+ packet_send();
+ packet_write_wait();
+
+ type = packet_read();
+ if (type != SSH_SMSG_FAILURE &&
+ type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
+ packet_disconnect("Protocol error: got %d in response "
+ "to SSH_CMSG_AUTH_TIS", type);
+ }
+ if (type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
+ debug("No challenge.");
+ return 0;
+ }
+ challenge = packet_get_string(&clen);
+ packet_check_eom();
+ snprintf(prompt, sizeof prompt, "%s%s", challenge,
+ strchr(challenge, '\n') ? "" : "\nResponse: ");
+ xfree(challenge);
if (i != 0)
error("Permission denied, please try again.");
- response = read_passphrase("Response: ", 0);
+ if (options.cipher == SSH_CIPHER_NONE)
+ logit("WARNING: Encryption is disabled! "
+ "Response will be transmitted in clear text.");
+ response = read_passphrase(prompt, 0);
+ if (strcmp(response, "") == 0) {
+ xfree(response);
+ break;
+ }
packet_start(SSH_CMSG_AUTH_TIS_RESPONSE);
- packet_put_string(response, strlen(response));
+ ssh_put_password(response);
memset(response, 0, strlen(response));
xfree(response);
packet_send();
packet_write_wait();
- type = packet_read(&payload_len);
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS)
return 1;
if (type != SSH_SMSG_FAILURE)
packet_disconnect("Protocol error: got %d in response "
- "to skey-auth-reponse", type);
+ "to SSH_CMSG_AUTH_TIS_RESPONSE", type);
}
/* failure */
return 0;
/*
* Tries to authenticate with plain passwd authentication.
*/
-int
+static int
try_password_authentication(char *prompt)
{
- int type, i, payload_len;
+ int type, i;
char *password;
debug("Doing password authentication.");
if (options.cipher == SSH_CIPHER_NONE)
- log("WARNING: Encryption is disabled! Password will be transmitted in clear text.");
+ logit("WARNING: Encryption is disabled! Password will be transmitted in clear text.");
for (i = 0; i < options.number_of_password_prompts; i++) {
if (i != 0)
error("Permission denied, please try again.");
password = read_passphrase(prompt, 0);
packet_start(SSH_CMSG_AUTH_PASSWORD);
- packet_put_string(password, strlen(password));
+ ssh_put_password(password);
memset(password, 0, strlen(password));
xfree(password);
packet_send();
packet_write_wait();
- type = packet_read(&payload_len);
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS)
return 1;
if (type != SSH_SMSG_FAILURE)
{
int i;
BIGNUM *key;
- RSA *host_key;
- RSA *public_key;
- Key k;
+ Key *host_key, *server_key;
int bits, rbits;
int ssh_cipher_default = SSH_CIPHER_3DES;
- unsigned char session_key[SSH_SESSION_KEY_LENGTH];
- unsigned char cookie[8];
- unsigned int supported_ciphers;
- unsigned int server_flags, client_flags;
- int payload_len, clen, sum_len = 0;
- u_int32_t rand = 0;
+ u_char session_key[SSH_SESSION_KEY_LENGTH];
+ u_char cookie[8];
+ u_int supported_ciphers;
+ u_int server_flags, client_flags;
+ u_int32_t rnd = 0;
debug("Waiting for server public key.");
/* Wait for a public key packet from the server. */
- packet_read_expect(&payload_len, SSH_SMSG_PUBLIC_KEY);
+ packet_read_expect(SSH_SMSG_PUBLIC_KEY);
/* Get cookie from the packet. */
for (i = 0; i < 8; i++)
cookie[i] = packet_get_char();
/* Get the public key. */
- public_key = RSA_new();
- bits = packet_get_int();/* bits */
- public_key->e = BN_new();
- packet_get_bignum(public_key->e, &clen);
- sum_len += clen;
- public_key->n = BN_new();
- packet_get_bignum(public_key->n, &clen);
- sum_len += clen;
-
- rbits = BN_num_bits(public_key->n);
+ server_key = key_new(KEY_RSA1);
+ bits = packet_get_int();
+ packet_get_bignum(server_key->rsa->e);
+ packet_get_bignum(server_key->rsa->n);
+
+ rbits = BN_num_bits(server_key->rsa->n);
if (bits != rbits) {
- log("Warning: Server lies about size of server public key: "
+ logit("Warning: Server lies about size of server public key: "
"actual size is %d bits vs. announced %d.", rbits, bits);
- log("Warning: This may be due to an old implementation of ssh.");
+ logit("Warning: This may be due to an old implementation of ssh.");
}
/* Get the host key. */
- host_key = RSA_new();
- bits = packet_get_int();/* bits */
- host_key->e = BN_new();
- packet_get_bignum(host_key->e, &clen);
- sum_len += clen;
- host_key->n = BN_new();
- packet_get_bignum(host_key->n, &clen);
- sum_len += clen;
-
- rbits = BN_num_bits(host_key->n);
+ host_key = key_new(KEY_RSA1);
+ bits = packet_get_int();
+ packet_get_bignum(host_key->rsa->e);
+ packet_get_bignum(host_key->rsa->n);
+
+ rbits = BN_num_bits(host_key->rsa->n);
if (bits != rbits) {
- log("Warning: Server lies about size of server host key: "
+ logit("Warning: Server lies about size of server host key: "
"actual size is %d bits vs. announced %d.", rbits, bits);
- log("Warning: This may be due to an old implementation of ssh.");
+ logit("Warning: This may be due to an old implementation of ssh.");
}
/* Get protocol flags. */
supported_ciphers = packet_get_int();
supported_authentications = packet_get_int();
+ packet_check_eom();
debug("Received server public key (%d bits) and host key (%d bits).",
- BN_num_bits(public_key->n), BN_num_bits(host_key->n));
+ BN_num_bits(server_key->rsa->n), BN_num_bits(host_key->rsa->n));
- packet_integrity_check(payload_len,
- 8 + 4 + sum_len + 0 + 4 + 0 + 0 + 4 + 4 + 4,
- SSH_SMSG_PUBLIC_KEY);
- k.type = KEY_RSA;
- k.rsa = host_key;
- check_host_key(host, hostaddr, &k,
- options.user_hostfile, options.system_hostfile);
+ if (verify_host_key(host, hostaddr, host_key) == -1)
+ fatal("Host key verification failed.");
client_flags = SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN;
- compute_session_id(session_id, cookie, host_key->n, public_key->n);
+ derive_ssh1_session_id(host_key->rsa->n, server_key->rsa->n, cookie, session_id);
/* Generate a session key. */
arc4random_stir();
*/
for (i = 0; i < 32; i++) {
if (i % 4 == 0)
- rand = arc4random();
- session_key[i] = rand & 0xff;
- rand >>= 8;
+ rnd = arc4random();
+ session_key[i] = rnd & 0xff;
+ rnd >>= 8;
}
/*
* is the highest byte of the integer. The session key is xored with
* the first 16 bytes of the session id.
*/
- key = BN_new();
- BN_set_word(key, 0);
+ if ((key = BN_new()) == NULL)
+ fatal("ssh_kex: BN_new failed");
+ if (BN_set_word(key, 0) == 0)
+ fatal("ssh_kex: BN_set_word failed");
for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
- BN_lshift(key, key, 8);
- if (i < 16)
- BN_add_word(key, session_key[i] ^ session_id[i]);
- else
- BN_add_word(key, session_key[i]);
+ if (BN_lshift(key, key, 8) == 0)
+ fatal("ssh_kex: BN_lshift failed");
+ if (i < 16) {
+ if (BN_add_word(key, session_key[i] ^ session_id[i])
+ == 0)
+ fatal("ssh_kex: BN_add_word failed");
+ } else {
+ if (BN_add_word(key, session_key[i]) == 0)
+ fatal("ssh_kex: BN_add_word failed");
+ }
}
/*
* Encrypt the integer using the public key and host key of the
* server (key with smaller modulus first).
*/
- if (BN_cmp(public_key->n, host_key->n) < 0) {
+ if (BN_cmp(server_key->rsa->n, host_key->rsa->n) < 0) {
/* Public key has smaller modulus. */
- if (BN_num_bits(host_key->n) <
- BN_num_bits(public_key->n) + SSH_KEY_BITS_RESERVED) {
- fatal("respond_to_rsa_challenge: host_key %d < public_key %d + "
- "SSH_KEY_BITS_RESERVED %d",
- BN_num_bits(host_key->n),
- BN_num_bits(public_key->n),
- SSH_KEY_BITS_RESERVED);
+ if (BN_num_bits(host_key->rsa->n) <
+ BN_num_bits(server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
+ fatal("respond_to_rsa_challenge: host_key %d < server_key %d + "
+ "SSH_KEY_BITS_RESERVED %d",
+ BN_num_bits(host_key->rsa->n),
+ BN_num_bits(server_key->rsa->n),
+ SSH_KEY_BITS_RESERVED);
}
- rsa_public_encrypt(key, key, public_key);
- rsa_public_encrypt(key, key, host_key);
+ rsa_public_encrypt(key, key, server_key->rsa);
+ rsa_public_encrypt(key, key, host_key->rsa);
} else {
/* Host key has smaller modulus (or they are equal). */
- if (BN_num_bits(public_key->n) <
- BN_num_bits(host_key->n) + SSH_KEY_BITS_RESERVED) {
- fatal("respond_to_rsa_challenge: public_key %d < host_key %d + "
- "SSH_KEY_BITS_RESERVED %d",
- BN_num_bits(public_key->n),
- BN_num_bits(host_key->n),
- SSH_KEY_BITS_RESERVED);
+ if (BN_num_bits(server_key->rsa->n) <
+ BN_num_bits(host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
+ fatal("respond_to_rsa_challenge: server_key %d < host_key %d + "
+ "SSH_KEY_BITS_RESERVED %d",
+ BN_num_bits(server_key->rsa->n),
+ BN_num_bits(host_key->rsa->n),
+ SSH_KEY_BITS_RESERVED);
}
- rsa_public_encrypt(key, key, host_key);
- rsa_public_encrypt(key, key, public_key);
+ rsa_public_encrypt(key, key, host_key->rsa);
+ rsa_public_encrypt(key, key, server_key->rsa);
}
/* Destroy the public keys since we no longer need them. */
- RSA_free(public_key);
- RSA_free(host_key);
+ key_free(server_key);
+ key_free(host_key);
if (options.cipher == SSH_CIPHER_NOT_SET) {
- if (cipher_mask1() & supported_ciphers & (1 << ssh_cipher_default))
+ if (cipher_mask_ssh1(1) & supported_ciphers & (1 << ssh_cipher_default))
options.cipher = ssh_cipher_default;
- else {
- debug("Cipher %s not supported, using %.100s instead.",
- cipher_name(ssh_cipher_default),
- cipher_name(SSH_FALLBACK_CIPHER));
- options.cipher = SSH_FALLBACK_CIPHER;
- }
+ } else if (options.cipher == SSH_CIPHER_INVALID ||
+ !(cipher_mask_ssh1(1) & (1 << options.cipher))) {
+ logit("No valid SSH1 cipher, using %.100s instead.",
+ cipher_name(ssh_cipher_default));
+ options.cipher = ssh_cipher_default;
}
/* Check that the selected cipher is supported. */
if (!(supported_ciphers & (1 << options.cipher)))
fatal("Selected cipher type %.100s not supported by server.",
- cipher_name(options.cipher));
+ cipher_name(options.cipher));
debug("Encryption type: %.100s", cipher_name(options.cipher));
* Expect a success message from the server. Note that this message
* will be received in encrypted form.
*/
- packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
+ packet_read_expect(SSH_SMSG_SUCCESS);
debug("Received encrypted confirmation.");
}
* Authenticate user
*/
void
-ssh_userauth(
- const char* local_user,
- const char* server_user,
- char *host,
- int host_key_valid, RSA *own_host_key)
+ssh_userauth1(const char *local_user, const char *server_user, char *host,
+ Sensitive *sensitive)
{
int i, type;
- int payload_len;
if (supported_authentications == 0)
- fatal("ssh_userauth: server supports no auth methods");
+ fatal("ssh_userauth1: server supports no auth methods");
/* Send the name of the user to log in as on the server. */
packet_start(SSH_CMSG_USER);
- packet_put_string(server_user, strlen(server_user));
+ packet_put_cstring(server_user);
packet_send();
packet_write_wait();
* needed (the user has no password). Otherwise the server responds
* with failure.
*/
- type = packet_read(&payload_len);
+ type = packet_read();
/* check whether the connection was accepted without authentication. */
if (type == SSH_SMSG_SUCCESS)
- return;
+ goto success;
if (type != SSH_SMSG_FAILURE)
- packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER",
- type);
+ packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type);
-#ifdef AFS
- /* Try Kerberos tgt passing if the server supports it. */
- if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
- options.kerberos_tgt_passing) {
- if (options.cipher == SSH_CIPHER_NONE)
- log("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
- (void) send_kerberos_tgt();
- }
- /* Try AFS token passing if the server supports it. */
- if ((supported_authentications & (1 << SSH_PASS_AFS_TOKEN)) &&
- options.afs_token_passing && k_hasafs()) {
- if (options.cipher == SSH_CIPHER_NONE)
- log("WARNING: Encryption is disabled! Token will be transmitted in the clear!");
- send_afs_tokens();
- }
-#endif /* AFS */
-
-#ifdef KRB4
- if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
- options.kerberos_authentication) {
- debug("Trying Kerberos authentication.");
- if (try_kerberos_authentication()) {
- /* The server should respond with success or failure. */
- type = packet_read(&payload_len);
- if (type == SSH_SMSG_SUCCESS)
- return;
- if (type != SSH_SMSG_FAILURE)
- packet_disconnect("Protocol error: got %d in response to Kerberos auth", type);
- }
- }
-#endif /* KRB4 */
-
- /*
- * Use rhosts authentication if running in privileged socket and we
- * do not wish to remain anonymous.
- */
- if ((supported_authentications & (1 << SSH_AUTH_RHOSTS)) &&
- options.rhosts_authentication) {
- debug("Trying rhosts authentication.");
- packet_start(SSH_CMSG_AUTH_RHOSTS);
- packet_put_string(local_user, strlen(local_user));
- packet_send();
- packet_write_wait();
-
- /* The server should respond with success or failure. */
- type = packet_read(&payload_len);
- if (type == SSH_SMSG_SUCCESS)
- return;
- if (type != SSH_SMSG_FAILURE)
- packet_disconnect("Protocol error: got %d in response to rhosts auth",
- type);
- }
/*
* Try .rhosts or /etc/hosts.equiv authentication with RSA host
* authentication.
*/
if ((supported_authentications & (1 << SSH_AUTH_RHOSTS_RSA)) &&
- options.rhosts_rsa_authentication && host_key_valid) {
- if (try_rhosts_rsa_authentication(local_user, own_host_key))
- return;
+ options.rhosts_rsa_authentication) {
+ for (i = 0; i < sensitive->nkeys; i++) {
+ if (sensitive->keys[i] != NULL &&
+ sensitive->keys[i]->type == KEY_RSA1 &&
+ try_rhosts_rsa_authentication(local_user,
+ sensitive->keys[i]))
+ goto success;
+ }
}
/* Try RSA authentication if the server supports it. */
if ((supported_authentications & (1 << SSH_AUTH_RSA)) &&
* it, whereas identity files may require passphrases.
*/
if (try_agent_authentication())
- return;
+ goto success;
/* Try RSA authentication for each identity. */
for (i = 0; i < options.num_identity_files; i++)
- if (try_rsa_authentication(options.identity_files[i]))
- return;
+ if (options.identity_keys[i] != NULL &&
+ options.identity_keys[i]->type == KEY_RSA1 &&
+ try_rsa_authentication(i))
+ goto success;
}
- /* Try skey authentication if the server supports it. */
+ /* Try challenge response authentication if the server supports it. */
if ((supported_authentications & (1 << SSH_AUTH_TIS)) &&
- options.skey_authentication && !options.batch_mode) {
- if (try_skey_authentication())
- return;
+ options.challenge_response_authentication && !options.batch_mode) {
+ if (try_challenge_response_authentication())
+ goto success;
}
/* Try password authentication if the server supports it. */
if ((supported_authentications & (1 << SSH_AUTH_PASSWORD)) &&
options.password_authentication && !options.batch_mode) {
char prompt[80];
- snprintf(prompt, sizeof(prompt), "%.30s@%.40s's password: ",
+ snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
server_user, host);
if (try_password_authentication(prompt))
- return;
+ goto success;
}
/* All authentication methods have failed. Exit with an error message. */
fatal("Permission denied.");
/* NOTREACHED */
+
+ success:
+ return; /* need statement after label */
}
andersk / openssh.git / blobdiff