*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect1.c,v 1.32 2001/05/18 14:13:29 markus Exp $");
+RCSID("$OpenBSD: sshconnect1.c,v 1.53 2003/04/08 20:21:29 itojun Exp $");
#include <openssl/bn.h>
-#include <openssl/evp.h>
+#include <openssl/md5.h>
#ifdef KRB4
#include <krb.h>
#endif
+#ifdef KRB5
+#include <krb5.h>
+#ifndef HEIMDAL
+#define krb5_get_err_text(context,code) error_message(code)
+#endif /* !HEIMDAL */
+#endif
#ifdef AFS
#include <kafs.h>
#include "radix.h"
#include "readpass.h"
#include "cipher.h"
#include "canohost.h"
+#include "auth.h"
/* Session id for the current session. */
u_char session_id[16];
* Checks if the user has an authentication agent, and if so, tries to
* authenticate using the agent.
*/
-int
+static int
try_agent_authentication(void)
{
int type;
AuthenticationConnection *auth;
u_char response[16];
u_int i;
- int plen, clen;
Key *key;
BIGNUM *challenge;
if (!auth)
return 0;
- challenge = BN_new();
-
+ if ((challenge = BN_new()) == NULL)
+ fatal("try_agent_authentication: BN_new failed");
/* Loop through identities served by the agent. */
for (key = ssh_get_first_identity(auth, &comment, 1);
- key != NULL;
- key = ssh_get_next_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);
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
does not support RSA authentication. */
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.");
* although it advertised it supports this. Just
* return a wrong value.
*/
- log("Authentication agent failed to decrypt challenge.");
+ logit("Authentication agent failed to decrypt challenge.");
memset(response, 0, sizeof(response));
}
key_free(key);
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) {
* 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)
{
u_char buf[32], response[16];
* 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, type, quit;
+
+ public = options.identity_keys[idx];
+ authfile = options.identity_files[idx];
+ comment = xstrdup(authfile);
- /* Try to load identification for the authentication key. */
- /* XXKEYLOAD */
- public = key_load_public_type(KEY_RSA1, authfile, &comment);
- if (public == NULL) {
- /* 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
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.");
/*
- * 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.
*/
- private = key_load_private_type(KEY_RSA1, authfile, "", NULL);
- if (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);
+ if (private == NULL && !options.batch_mode) {
+ 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. */
- private = key_load_private_type(KEY_RSA1, authfile, passphrase, NULL);
- if (private == NULL) {
+ if (strcmp(passphrase, "") != 0) {
+ private = key_load_private_type(KEY_RSA1,
+ authfile, passphrase, 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);
- BN_clear_free(challenge);
- 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)
+ 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
+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_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_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.");
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;
}
#ifdef KRB4
-int
-try_kerberos_authentication(void)
+static int
+try_krb4_authentication(void)
{
KTEXT_ST auth; /* Kerberos data */
char *reply;
char inst[INST_SZ];
char *realm;
CREDENTIALS cred;
- int r, type, plen;
+ int r, type;
socklen_t slen;
Key_schedule schedule;
u_long checksum, cksum;
if (stat(tkt_string(), &st) < 0)
return 0;
- strncpy(inst, (char *) krb_get_phost(get_canonical_hostname(1)), INST_SZ);
+ strlcpy(inst, (char *)krb_get_phost(get_canonical_hostname(1)),
+ INST_SZ);
- realm = (char *) krb_realmofhost(get_canonical_hostname(1));
+ realm = (char *)krb_realmofhost(get_canonical_hostname(1));
if (!realm) {
- debug("Kerberos V4: no realm for %s", get_canonical_hostname(1));
+ debug("Kerberos v4: no realm for %s", get_canonical_hostname(1));
return 0;
}
/* This can really be anything. */
- checksum = (u_long) getpid();
+ 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]);
+ debug("Kerberos v4 krb_mk_req failed: %s", krb_err_txt[r]);
return 0;
}
/* Get session key to decrypt the server's reply with. */
slen = sizeof(local);
memset(&local, 0, sizeof(local));
if (getsockname(packet_get_connection_in(),
- (struct sockaddr *) & local, &slen) < 0)
+ (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) {
+ (struct sockaddr *)&foreign, &slen) < 0) {
debug("getpeername failed: %s", strerror(errno));
fatal_cleanup();
}
/* Get server reply. */
- type = packet_read(&plen);
+ type = packet_read();
switch (type) {
case SSH_SMSG_FAILURE:
/* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
- debug("Kerberos V4 authentication failed.");
+ debug("Kerberos v4 authentication failed.");
return 0;
break;
case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
/* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
- debug("Kerberos V4 authentication accepted.");
+ debug("Kerberos v4 authentication accepted.");
/* Get server's response. */
reply = packet_get_string((u_int *) &auth.length);
+ if (auth.length >= MAX_KTXT_LEN)
+ fatal("Kerberos v4: Malformed response from server");
memcpy(auth.dat, reply, auth.length);
xfree(reply);
- packet_integrity_check(plen, 4 + auth.length, type);
+ packet_check_eom();
/*
* If his response isn't properly encrypted with the session
* bogus. Bail out.
*/
r = krb_rd_priv(auth.dat, auth.length, schedule, &cred.session,
- &foreign, &local, &msg_data);
+ &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!");
+ 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));
+ 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.");
+ debug("Kerberos v4 challenge successful.");
return 1;
} else
- packet_disconnect("Kerberos V4 challenge failed!");
+ packet_disconnect("Kerberos v4 challenge failed!");
break;
default:
- packet_disconnect("Protocol error on Kerberos V4 response: %d", type);
+ packet_disconnect("Protocol error on Kerberos v4 response: %d", type);
}
return 0;
}
#endif /* KRB4 */
+#ifdef KRB5
+static int
+try_krb5_authentication(krb5_context *context, krb5_auth_context *auth_context)
+{
+ krb5_error_code problem;
+ const char *tkfile;
+ struct stat buf;
+ krb5_ccache ccache = NULL;
+ const char *remotehost;
+ krb5_data ap;
+ int type;
+ krb5_ap_rep_enc_part *reply = NULL;
+ int ret;
+
+ memset(&ap, 0, sizeof(ap));
+
+ problem = krb5_init_context(context);
+ if (problem) {
+ debug("Kerberos v5: krb5_init_context failed");
+ ret = 0;
+ goto out;
+ }
+
+ problem = krb5_auth_con_init(*context, auth_context);
+ if (problem) {
+ debug("Kerberos v5: krb5_auth_con_init failed");
+ ret = 0;
+ goto out;
+ }
+
+#ifndef HEIMDAL
+ problem = krb5_auth_con_setflags(*context, *auth_context,
+ KRB5_AUTH_CONTEXT_RET_TIME);
+ if (problem) {
+ debug("Keberos v5: krb5_auth_con_setflags failed");
+ ret = 0;
+ goto out;
+ }
+#endif
+
+ tkfile = krb5_cc_default_name(*context);
+ if (strncmp(tkfile, "FILE:", 5) == 0)
+ tkfile += 5;
+
+ if (stat(tkfile, &buf) == 0 && getuid() != buf.st_uid) {
+ debug("Kerberos v5: could not get default ccache (permission denied).");
+ ret = 0;
+ goto out;
+ }
+
+ problem = krb5_cc_default(*context, &ccache);
+ if (problem) {
+ debug("Kerberos v5: krb5_cc_default failed: %s",
+ krb5_get_err_text(*context, problem));
+ ret = 0;
+ goto out;
+ }
+
+ remotehost = get_canonical_hostname(1);
+
+ problem = krb5_mk_req(*context, auth_context, AP_OPTS_MUTUAL_REQUIRED,
+ "host", remotehost, NULL, ccache, &ap);
+ if (problem) {
+ debug("Kerberos v5: krb5_mk_req failed: %s",
+ krb5_get_err_text(*context, problem));
+ ret = 0;
+ goto out;
+ }
+
+ packet_start(SSH_CMSG_AUTH_KERBEROS);
+ packet_put_string((char *) ap.data, ap.length);
+ packet_send();
+ packet_write_wait();
+
+ xfree(ap.data);
+ ap.length = 0;
+
+ type = packet_read();
+ switch (type) {
+ case SSH_SMSG_FAILURE:
+ /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
+ debug("Kerberos v5 authentication failed.");
+ ret = 0;
+ break;
+
+ case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
+ /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
+ debug("Kerberos v5 authentication accepted.");
+
+ /* Get server's response. */
+ ap.data = packet_get_string((unsigned int *) &ap.length);
+ packet_check_eom();
+ /* XXX je to dobre? */
+
+ problem = krb5_rd_rep(*context, *auth_context, &ap, &reply);
+ if (problem) {
+ ret = 0;
+ }
+ ret = 1;
+ break;
+
+ default:
+ packet_disconnect("Protocol error on Kerberos v5 response: %d",
+ type);
+ ret = 0;
+ break;
+
+ }
+
+ out:
+ if (ccache != NULL)
+ krb5_cc_close(*context, ccache);
+ if (reply != NULL)
+ krb5_free_ap_rep_enc_part(*context, reply);
+ if (ap.length > 0)
+#ifdef HEIMDAL
+ krb5_data_free(&ap);
+#else
+ krb5_free_data_contents(*context, &ap);
+#endif
+
+ return (ret);
+}
+
+static void
+send_krb5_tgt(krb5_context context, krb5_auth_context auth_context)
+{
+ int fd, type;
+ krb5_error_code problem;
+ krb5_data outbuf;
+ krb5_ccache ccache = NULL;
+ krb5_creds creds;
+#ifdef HEIMDAL
+ krb5_kdc_flags flags;
+#else
+ int forwardable;
+#endif
+ const char *remotehost;
+
+ memset(&creds, 0, sizeof(creds));
+ memset(&outbuf, 0, sizeof(outbuf));
+
+ fd = packet_get_connection_in();
+
+#ifdef HEIMDAL
+ problem = krb5_auth_con_setaddrs_from_fd(context, auth_context, &fd);
+#else
+ problem = krb5_auth_con_genaddrs(context, auth_context, fd,
+ KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR |
+ KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR);
+#endif
+ if (problem)
+ goto out;
+
+ problem = krb5_cc_default(context, &ccache);
+ if (problem)
+ goto out;
+
+ problem = krb5_cc_get_principal(context, ccache, &creds.client);
+ if (problem)
+ goto out;
+
+ remotehost = get_canonical_hostname(1);
+
+#ifdef HEIMDAL
+ problem = krb5_build_principal(context, &creds.server,
+ strlen(creds.client->realm), creds.client->realm,
+ "krbtgt", creds.client->realm, NULL);
+#else
+ problem = krb5_build_principal(context, &creds.server,
+ creds.client->realm.length, creds.client->realm.data,
+ "host", remotehost, NULL);
+#endif
+ if (problem)
+ goto out;
+
+ creds.times.endtime = 0;
+
+#ifdef HEIMDAL
+ flags.i = 0;
+ flags.b.forwarded = 1;
+ flags.b.forwardable = krb5_config_get_bool(context, NULL,
+ "libdefaults", "forwardable", NULL);
+ problem = krb5_get_forwarded_creds(context, auth_context,
+ ccache, flags.i, remotehost, &creds, &outbuf);
+#else
+ forwardable = 1;
+ problem = krb5_fwd_tgt_creds(context, auth_context, remotehost,
+ creds.client, creds.server, ccache, forwardable, &outbuf);
+#endif
+
+ if (problem)
+ goto out;
+
+ packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
+ packet_put_string((char *)outbuf.data, outbuf.length);
+ packet_send();
+ packet_write_wait();
+
+ type = packet_read();
+
+ if (type == SSH_SMSG_SUCCESS) {
+ char *pname;
+
+ krb5_unparse_name(context, creds.client, &pname);
+ debug("Kerberos v5 TGT forwarded (%s).", pname);
+ xfree(pname);
+ } else
+ debug("Kerberos v5 TGT forwarding failed.");
+
+ return;
+
+ out:
+ if (problem)
+ debug("Kerberos v5 TGT forwarding failed: %s",
+ krb5_get_err_text(context, problem));
+ if (creds.client)
+ krb5_free_principal(context, creds.client);
+ if (creds.server)
+ krb5_free_principal(context, creds.server);
+ if (ccache)
+ krb5_cc_close(context, ccache);
+ if (outbuf.data)
+ xfree(outbuf.data);
+}
+#endif /* KRB5 */
+
#ifdef AFS
-int
-send_kerberos_tgt(void)
+static void
+send_krb4_tgt(void)
{
CREDENTIALS *creds;
- char pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ];
- int r, type, plen;
- char buffer[8192];
struct stat st;
+ char buffer[4096], pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ];
+ int problem, type;
/* Don't do anything if we don't have any tickets. */
if (stat(tkt_string(), &st) < 0)
- return 0;
+ return;
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;
- }
+ problem = krb_get_tf_fullname(TKT_FILE, pname, pinst, prealm);
+ if (problem)
+ goto out;
+
+ problem = krb_get_cred("krbtgt", prealm, prealm, creds);
+ if (problem)
+ goto out;
+
if (time(0) > krb_life_to_time(creds->issue_date, creds->lifetime)) {
- debug("Kerberos V4 ticket expired: %s", TKT_FILE);
- return 0;
+ problem = RD_AP_EXP;
+ goto out;
}
- creds_to_radix(creds, (u_char *)buffer, sizeof buffer);
- xfree(creds);
+ creds_to_radix(creds, (u_char *)buffer, sizeof(buffer));
packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
- packet_put_string(buffer, strlen(buffer));
+ packet_put_cstring(buffer);
packet_send();
packet_write_wait();
- type = packet_read(&plen);
+ type = packet_read();
- 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);
+ if (type == SSH_SMSG_SUCCESS)
+ debug("Kerberos v4 TGT forwarded (%s%s%s@%s).",
+ creds->pname, creds->pinst[0] ? "." : "",
+ creds->pinst, creds->realm);
+ else
+ debug("Kerberos v4 TGT rejected.");
+
+ xfree(creds);
+ return;
- return 1;
+ out:
+ debug("Kerberos v4 TGT passing failed: %s", krb_err_txt[problem]);
+ xfree(creds);
}
-void
+static void
send_afs_tokens(void)
{
CREDENTIALS creds;
struct ViceIoctl parms;
struct ClearToken ct;
- int i, type, len, plen;
+ int i, type, len;
char buf[2048], *p, *server_cell;
char buffer[8192];
server_cell = p;
/* Flesh out our credentials. */
- strlcpy(creds.service, "afs", sizeof creds.service);
+ 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.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, (u_char *) buffer, sizeof buffer) <= 0)
+ if (creds_to_radix(&creds, (u_char *)buffer,
+ sizeof(buffer)) <= 0)
break;
packet_start(SSH_CMSG_HAVE_AFS_TOKEN);
- packet_put_string(buffer, strlen(buffer));
+ packet_put_cstring(buffer);
packet_send();
packet_write_wait();
/* Roger, Roger. Clearance, Clarence. What's your vector,
Victor? */
- type = packet_read(&plen);
+ type = packet_read();
if (type == SSH_SMSG_FAILURE)
debug("AFS token for cell %s rejected.", server_cell);
* Tries to authenticate with any string-based challenge/response system.
* Note that the client code is not tied to s/key or TIS.
*/
-int
+static int
try_challenge_response_authentication(void)
{
int type, i;
- int payload_len;
u_int clen;
char prompt[1024];
char *challenge, *response;
- debug("Doing challenge reponse authentication.");
+ debug("Doing challenge response authentication.");
for (i = 0; i < options.number_of_password_prompts; i++) {
/* request a challenge */
packet_send();
packet_write_wait();
- type = packet_read(&payload_len);
+ type = packet_read();
if (type != SSH_SMSG_FAILURE &&
type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
packet_disconnect("Protocol error: got %d in response "
return 0;
}
challenge = packet_get_string(&clen);
- packet_integrity_check(payload_len, (4 + clen), type);
+ packet_check_eom();
snprintf(prompt, sizeof prompt, "%s%s", challenge,
- strchr(challenge, '\n') ? "" : "\nResponse: ");
+ strchr(challenge, '\n') ? "" : "\nResponse: ");
xfree(challenge);
if (i != 0)
error("Permission denied, please try again.");
if (options.cipher == SSH_CIPHER_NONE)
- log("WARNING: Encryption is disabled! "
- "Reponse will be transmitted in clear text.");
+ logit("WARNING: Encryption is disabled! "
+ "Response will be transmitted in clear text.");
response = read_passphrase(prompt, 0);
if (strcmp(response, "") == 0) {
xfree(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)
/*
* 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.");
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;
u_char session_key[SSH_SESSION_KEY_LENGTH];
u_char cookie[8];
u_int supported_ciphers;
u_int server_flags, client_flags;
- int payload_len, clen, sum_len = 0;
u_int32_t rand = 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_RSA1;
- 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);
+ compute_session_id(session_id, cookie, host_key->rsa->n, server_key->rsa->n);
/* Generate a session key. */
arc4random_stir();
* is the highest byte of the integer. The session key is xored with
* the first 16 bytes of the session id.
*/
- key = BN_new();
+ if ((key = BN_new()) == NULL)
+ fatal("respond_to_rsa_challenge: BN_new failed");
BN_set_word(key, 0);
for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
BN_lshift(key, key, 8);
* 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_mask_ssh1(1) & supported_ciphers & (1 << ssh_cipher_default))
options.cipher = ssh_cipher_default;
} else if (options.cipher == SSH_CIPHER_ILLEGAL ||
!(cipher_mask_ssh1(1) & (1 << options.cipher))) {
- log("No valid SSH1 cipher, using %.100s instead.",
+ 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.");
}
*/
void
ssh_userauth1(const char *local_user, const char *server_user, char *host,
- Key **keys, int nkeys)
+ Sensitive *sensitive)
{
+#ifdef KRB5
+ krb5_context context = NULL;
+ krb5_auth_context auth_context = NULL;
+#endif
int i, type;
- int payload_len;
if (supported_authentications == 0)
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();
+#ifdef KRB5
+ if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
+ options.kerberos_authentication) {
+ debug("Trying Kerberos v5 authentication.");
+
+ if (try_krb5_authentication(&context, &auth_context)) {
+ type = packet_read();
+ if (type == SSH_SMSG_SUCCESS)
+ goto success;
+ if (type != SSH_SMSG_FAILURE)
+ packet_disconnect("Protocol error: got %d in response to Kerberos v5 auth", type);
+ }
}
-#endif /* AFS */
+#endif /* KRB5 */
#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);
+ debug("Trying Kerberos v4 authentication.");
+
+ if (try_krb4_authentication()) {
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS)
- return;
+ goto success;
if (type != SSH_SMSG_FAILURE)
- packet_disconnect("Protocol error: got %d in response to Kerberos auth", type);
+ packet_disconnect("Protocol error: got %d in response to Kerberos v4 auth", type);
}
}
#endif /* KRB4 */
options.rhosts_authentication) {
debug("Trying rhosts authentication.");
packet_start(SSH_CMSG_AUTH_RHOSTS);
- packet_put_string(local_user, strlen(local_user));
+ packet_put_cstring(local_user);
packet_send();
packet_write_wait();
/* The server should respond with success or failure. */
- type = packet_read(&payload_len);
+ type = packet_read();
if (type == SSH_SMSG_SUCCESS)
- return;
+ goto success;
if (type != SSH_SMSG_FAILURE)
packet_disconnect("Protocol error: got %d in response to rhosts auth",
type);
*/
if ((supported_authentications & (1 << SSH_AUTH_RHOSTS_RSA)) &&
options.rhosts_rsa_authentication) {
- for (i = 0; i < nkeys; i++) {
- if (keys[i] != NULL && keys[i]->type == KEY_RSA1 &&
- try_rhosts_rsa_authentication(local_user, keys[i]))
- return;
+ 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. */
* 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 (options.identity_keys[i] != NULL &&
options.identity_keys[i]->type == KEY_RSA1 &&
- try_rsa_authentication(options.identity_files[i]))
- return;
+ try_rsa_authentication(i))
+ goto success;
}
/* Try challenge response authentication if the server supports it. */
if ((supported_authentications & (1 << SSH_AUTH_TIS)) &&
options.challenge_response_authentication && !options.batch_mode) {
if (try_challenge_response_authentication())
- return;
+ goto success;
}
/* Try password authentication if the server supports it. */
if ((supported_authentications & (1 << SSH_AUTH_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:
+#ifdef KRB5
+ /* Try Kerberos v5 TGT passing. */
+ if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
+ options.kerberos_tgt_passing && context && auth_context) {
+ if (options.cipher == SSH_CIPHER_NONE)
+ logit("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
+ send_krb5_tgt(context, auth_context);
+ }
+ if (auth_context)
+ krb5_auth_con_free(context, auth_context);
+ if (context)
+ krb5_free_context(context);
+#endif
+
+#ifdef AFS
+ /* Try Kerberos v4 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)
+ logit("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
+ send_krb4_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)
+ logit("WARNING: Encryption is disabled! Token will be transmitted in the clear!");
+ send_afs_tokens();
+ }
+#endif /* AFS */
+
+ return; /* need statement after label */
}