X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/1c59025848be8ebfcd37d2ba3dbf73600643675d..HEAD:/sshconnect1.c diff --git a/sshconnect1.c b/sshconnect1.c index 8851c35f..fd07bbf7 100644 --- a/sshconnect1.c +++ b/sshconnect1.c @@ -1,3 +1,4 @@ +/* $OpenBSD: sshconnect1.c,v 1.70 2006/11/06 21:25:28 markus Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -13,35 +14,38 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect1.c,v 1.54 2003/07/22 13:35:22 markus Exp $"); + +#include +#include #include #include -#ifdef KRB5 -#include -#ifndef HEIMDAL -#define krb5_get_err_text(context,code) error_message(code) -#endif /* !HEIMDAL */ -#endif +#include +#include +#include +#include +#include +#include +#include "xmalloc.h" #include "ssh.h" #include "ssh1.h" -#include "xmalloc.h" #include "rsa.h" #include "buffer.h" #include "packet.h" -#include "mpaux.h" +#include "key.h" +#include "cipher.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 "readpass.h" -#include "cipher.h" +#include "misc.h" #include "canohost.h" +#include "hostfile.h" #include "auth.h" /* Session id for the current session. */ @@ -91,7 +95,7 @@ try_agent_authentication(void) /* Wait for server's response. */ 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."); @@ -169,7 +173,7 @@ respond_to_rsa_challenge(BIGNUM * challenge, RSA * prv) /* Compute the response. */ /* The response is MD5 of decrypted challenge plus session id. */ len = BN_num_bytes(challenge); - if (len <= 0 || len > sizeof(buf)) + if (len <= 0 || (u_int)len > sizeof(buf)) packet_disconnect( "respond_to_rsa_challenge: bad challenge length %d", len); @@ -204,7 +208,7 @@ try_rsa_authentication(int idx) BIGNUM *challenge; Key *public, *private; char buf[300], *passphrase, *comment, *authfile; - int i, type, quit; + int i, perm_ok = 1, type, quit; public = options.identity_keys[idx]; authfile = options.identity_files[idx]; @@ -222,8 +226,8 @@ try_rsa_authentication(int idx) 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."); @@ -250,15 +254,16 @@ try_rsa_authentication(int idx) if (public->flags & KEY_FLAG_EXT) private = public; else - private = key_load_private_type(KEY_RSA1, authfile, "", NULL); - if (private == NULL && !options.batch_mode) { + 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); if (strcmp(passphrase, "") != 0) { private = key_load_private_type(KEY_RSA1, - authfile, passphrase, NULL); + authfile, passphrase, NULL, NULL); quit = 0; } else { debug2("no passphrase given, try next key"); @@ -275,7 +280,7 @@ try_rsa_authentication(int idx) xfree(comment); if (private == NULL) { - if (!options.batch_mode) + if (!options.batch_mode && perm_ok) error("Bad passphrase."); /* Send a dummy response packet to avoid protocol error. */ @@ -373,233 +378,6 @@ try_rhosts_rsa_authentication(const char *local_user, Key * host_key) return 0; } -#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 */ - /* * Tries to authenticate with any string-based challenge/response system. * Note that the client code is not tied to s/key or TIS. @@ -710,7 +488,7 @@ ssh_kex(char *host, struct sockaddr *hostaddr) u_char cookie[8]; u_int supported_ciphers; u_int server_flags, client_flags; - u_int32_t rand = 0; + u_int32_t rnd = 0; debug("Waiting for server public key."); @@ -762,7 +540,7 @@ ssh_kex(char *host, struct sockaddr *hostaddr) client_flags = SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN; - compute_session_id(session_id, cookie, host_key->rsa->n, server_key->rsa->n); + derive_ssh1_session_id(host_key->rsa->n, server_key->rsa->n, cookie, session_id); /* Generate a session key. */ arc4random_stir(); @@ -774,9 +552,9 @@ ssh_kex(char *host, struct sockaddr *hostaddr) */ 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; } /* @@ -785,14 +563,20 @@ ssh_kex(char *host, struct sockaddr *hostaddr) * the first 16 bytes of the session id. */ if ((key = BN_new()) == NULL) - fatal("respond_to_rsa_challenge: BN_new failed"); - BN_set_word(key, 0); + 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"); + } } /* @@ -832,7 +616,7 @@ ssh_kex(char *host, struct sockaddr *hostaddr) 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 || + } 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)); @@ -888,10 +672,6 @@ void ssh_userauth1(const char *local_user, const char *server_user, char *host, Sensitive *sensitive) { -#ifdef KRB5 - krb5_context context = NULL; - krb5_auth_context auth_context = NULL; -#endif int i, type; if (supported_authentications == 0) @@ -916,41 +696,6 @@ ssh_userauth1(const char *local_user, const char *server_user, char *host, if (type != SSH_SMSG_FAILURE) packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type); -#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 /* KRB5 */ - - /* - * 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_cstring(local_user); - packet_send(); - packet_write_wait(); - - /* The server should respond with success or failure. */ - type = packet_read(); - if (type == SSH_SMSG_SUCCESS) - goto success; - 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. @@ -1004,18 +749,5 @@ ssh_userauth1(const char *local_user, const char *server_user, char *host, /* 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 return; /* need statement after label */ }