=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/Attic/auth1.c,v retrieving revision 1.2 retrieving revision 1.2.2.5 diff -u -r1.2 -r1.2.2.5 --- src/usr.bin/ssh/Attic/auth1.c 2000/04/29 18:11:52 1.2 +++ src/usr.bin/ssh/Attic/auth1.c 2001/03/21 18:52:34 1.2.2.5 @@ -1,26 +1,32 @@ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved + * + * 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: auth1.c,v 1.2 2000/04/29 18:11:52 markus Exp $"); +RCSID("$OpenBSD: auth1.c,v 1.2.2.5 2001/03/21 18:52:34 jason Exp $"); #include "xmalloc.h" #include "rsa.h" -#include "ssh.h" +#include "ssh1.h" #include "packet.h" #include "buffer.h" -#include "cipher.h" #include "mpaux.h" +#include "log.h" #include "servconf.h" #include "compat.h" #include "auth.h" #include "session.h" +#include "misc.h" /* import */ extern ServerOptions options; -extern char *forced_command; /* * convert ssh auth msg type into description @@ -38,113 +44,61 @@ return "rhosts-rsa"; case SSH_CMSG_AUTH_RHOSTS: return "rhosts"; + case SSH_CMSG_AUTH_TIS: + case SSH_CMSG_AUTH_TIS_RESPONSE: + return "challenge-response"; #ifdef KRB4 case SSH_CMSG_AUTH_KERBEROS: return "kerberos"; #endif -#ifdef SKEY - case SSH_CMSG_AUTH_TIS_RESPONSE: - return "s/key"; -#endif } snprintf(buf, sizeof buf, "bad-auth-msg-%d", type); return buf; } /* - * The user does not exist or access is denied, - * but fake indication that authentication is needed. + * read packets, try to authenticate the user and + * return only if authentication is successful */ void -do_fake_authloop1(char *user) +do_authloop(Authctxt *authctxt) { - int attempt = 0; - - log("Faking authloop for illegal user %.200s from %.200s port %d", - user, - get_remote_ipaddr(), - get_remote_port()); - - /* Indicate that authentication is needed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - - /* - * Keep reading packets, and always respond with a failure. This is - * to avoid disclosing whether such a user really exists. - */ - for (attempt = 1;; attempt++) { - /* Read a packet. This will not return if the client disconnects. */ - int plen; - int type = packet_read(&plen); -#ifdef SKEY - unsigned int dlen; - char *password, *skeyinfo; - password = NULL; - /* Try to send a fake s/key challenge. */ - if (options.skey_authentication == 1 && - (skeyinfo = skey_fake_keyinfo(user)) != NULL) { - if (type == SSH_CMSG_AUTH_TIS) { - packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_string(skeyinfo, strlen(skeyinfo)); - packet_send(); - packet_write_wait(); - continue; - } else if (type == SSH_CMSG_AUTH_PASSWORD && - options.password_authentication && - (password = packet_get_string(&dlen)) != NULL && - dlen == 5 && - strncasecmp(password, "s/key", 5) == 0 ) { - packet_send_debug(skeyinfo); - } - } - if (password != NULL) - xfree(password); -#endif - if (attempt > AUTH_FAIL_MAX) - packet_disconnect(AUTH_FAIL_MSG, user); - - /* - * Send failure. This should be indistinguishable from a - * failed authentication. - */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - } - /* NOTREACHED */ - abort(); -} - -/* - * read packets and try to authenticate local user *pw. - * return if authentication is successfull - */ -void -do_authloop(struct passwd * pw) -{ - int attempt = 0; - unsigned int bits; + int authenticated = 0; + u_int bits; RSA *client_host_key; BIGNUM *n; char *client_user, *password; - char user[1024]; - unsigned int dlen; + char info[1024]; + u_int dlen; int plen, nlen, elen; - unsigned int ulen; + u_int ulen; int type = 0; - void (*authlog) (const char *fmt,...) = verbose; + struct passwd *pw = authctxt->pw; + debug("Attempting authentication for %s%.100s.", + authctxt->valid ? "" : "illegal user ", authctxt->user); + + /* If the user has no password, accept authentication immediately. */ + if (options.password_authentication && +#ifdef KRB4 + (!options.kerberos_authentication || options.kerberos_or_local_passwd) && +#endif + auth_password(pw, "")) { + auth_log(authctxt, 1, "without authentication", ""); + return; + } + /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); - for (attempt = 1;; attempt++) { - int authenticated = 0; - strlcpy(user, "", sizeof user); + for (;;) { + /* default to fail */ + authenticated = 0; + info[0] = '\0'; + /* Get a packet from the client. */ type = packet_read(&plen); @@ -153,7 +107,6 @@ #ifdef AFS case SSH_CMSG_HAVE_KERBEROS_TGT: if (!options.kerberos_tgt_passing) { - /* packet_get_all(); */ verbose("Kerberos tgt passing disabled."); break; } else { @@ -161,14 +114,13 @@ char *tgt = packet_get_string(&dlen); packet_integrity_check(plen, 4 + dlen, type); if (!auth_kerberos_tgt(pw, tgt)) - verbose("Kerberos tgt REFUSED for %s", pw->pw_name); + verbose("Kerberos tgt REFUSED for %.100s", authctxt->user); xfree(tgt); } continue; case SSH_CMSG_HAVE_AFS_TOKEN: if (!options.afs_token_passing || !k_hasafs()) { - /* packet_get_all(); */ verbose("AFS token passing disabled."); break; } else { @@ -176,7 +128,7 @@ char *token_string = packet_get_string(&dlen); packet_integrity_check(plen, 4 + dlen, type); if (!auth_afs_token(pw, token_string)) - verbose("AFS token REFUSED for %s", pw->pw_name); + verbose("AFS token REFUSED for %.100s", authctxt->user); xfree(token_string); } continue; @@ -184,26 +136,26 @@ #ifdef KRB4 case SSH_CMSG_AUTH_KERBEROS: if (!options.kerberos_authentication) { - /* packet_get_all(); */ verbose("Kerberos authentication disabled."); break; } else { /* Try Kerberos v4 authentication. */ KTEXT_ST auth; char *tkt_user = NULL; - char *kdata = packet_get_string((unsigned int *) &auth.length); + char *kdata = packet_get_string((u_int *) &auth.length); packet_integrity_check(plen, 4 + auth.length, type); - if (auth.length < MAX_KTXT_LEN) - memcpy(auth.dat, kdata, auth.length); - xfree(kdata); - - authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); - - if (authenticated) { - snprintf(user, sizeof user, " tktuser %s", tkt_user); - xfree(tkt_user); + if (authctxt->valid) { + if (auth.length < MAX_KTXT_LEN) + memcpy(auth.dat, kdata, auth.length); + authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); + if (authenticated) { + snprintf(info, sizeof info, + " tktuser %.100s", tkt_user); + xfree(tkt_user); + } } + xfree(kdata); } break; #endif /* KRB4 */ @@ -222,11 +174,10 @@ client_user = packet_get_string(&ulen); packet_integrity_check(plen, 4 + ulen, type); - /* Try to authenticate using /etc/hosts.equiv and - .rhosts. */ + /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ authenticated = auth_rhosts(pw, client_user); - snprintf(user, sizeof user, " ruser %s", client_user); + snprintf(info, sizeof info, " ruser %.100s", client_user); xfree(client_user); break; @@ -255,14 +206,14 @@ packet_get_bignum(client_host_key->n, &nlen); if (bits != BN_num_bits(client_host_key->n)) - log("Warning: keysize mismatch for client_host_key: " + verbose("Warning: keysize mismatch for client_host_key: " "actual %d, announced %d", BN_num_bits(client_host_key->n), bits); packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); RSA_free(client_host_key); - snprintf(user, sizeof user, " ruser %s", client_user); + snprintf(info, sizeof info, " ruser %.100s", client_user); xfree(client_user); break; @@ -299,20 +250,14 @@ xfree(password); break; -#ifdef SKEY case SSH_CMSG_AUTH_TIS: debug("rcvd SSH_CMSG_AUTH_TIS"); - if (options.skey_authentication == 1) { - char *skeyinfo = skey_keyinfo(pw->pw_name); - if (skeyinfo == NULL) { - debug("generating fake skeyinfo for %.100s.", pw->pw_name); - skeyinfo = skey_fake_keyinfo(pw->pw_name); - } - if (skeyinfo != NULL) { - /* we send our s/key- in tis-challenge messages */ - debug("sending challenge '%s'", skeyinfo); + if (options.challenge_reponse_authentication == 1) { + char *challenge = get_challenge(authctxt, authctxt->style); + if (challenge != NULL) { + debug("sending challenge '%s'", challenge); packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_string(skeyinfo, strlen(skeyinfo)); + packet_put_cstring(challenge); packet_send(); packet_write_wait(); continue; @@ -321,21 +266,15 @@ break; case SSH_CMSG_AUTH_TIS_RESPONSE: debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); - if (options.skey_authentication == 1) { + if (options.challenge_reponse_authentication == 1) { char *response = packet_get_string(&dlen); - debug("skey response == '%s'", response); + debug("got response '%s'", response); packet_integrity_check(plen, 4 + dlen, type); - authenticated = (skey_haskey(pw->pw_name) == 0 && - skey_passcheck(pw->pw_name, response) != -1); + authenticated = verify_response(authctxt, response); + memset(response, 'r', dlen); xfree(response); } break; -#else - case SSH_CMSG_AUTH_TIS: - /* TIS Authentication is unsupported */ - log("TIS authentication unsupported."); - break; -#endif default: /* @@ -345,43 +284,24 @@ log("Unknown message during authentication: type %d", type); break; } + if (!authctxt->valid && authenticated) + fatal("INTERNAL ERROR: authenticated invalid user %s", + authctxt->user); - /* - * Check if the user is logging in as root and root logins - * are disallowed. - * Note that root login is allowed for forced commands. - */ - if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) { - if (forced_command) { - log("Root login accepted for forced command."); - } else { - authenticated = 0; - log("ROOT LOGIN REFUSED FROM %.200s", - get_canonical_hostname()); - } - } + /* Special handling for root */ + if (authenticated && authctxt->pw->pw_uid == 0 && + !auth_root_allowed(get_authname(type))) + authenticated = 0; - /* Raise logging level */ - if (authenticated || - attempt == AUTH_FAIL_LOG || - type == SSH_CMSG_AUTH_PASSWORD) - authlog = log; + /* Log before sending the reply */ + auth_log(authctxt, authenticated, get_authname(type), info); - authlog("%s %s for %.200s from %.200s port %d%s", - authenticated ? "Accepted" : "Failed", - get_authname(type), - pw->pw_uid == 0 ? "ROOT" : pw->pw_name, - get_remote_ipaddr(), - get_remote_port(), - user); - if (authenticated) return; - if (attempt > AUTH_FAIL_MAX) - packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); + if (authctxt->failures++ > AUTH_FAIL_MAX) + packet_disconnect(AUTH_FAIL_MSG, authctxt->user); - /* Send a message indicating that the authentication attempt failed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); @@ -395,10 +315,11 @@ void do_authentication() { - struct passwd *pw, pwcopy; + Authctxt *authctxt; + struct passwd *pw; int plen; - unsigned int ulen; - char *user; + u_int ulen; + char *user, *style = NULL; /* Get the name of the user that we wish to log in as. */ packet_read_expect(&plen, SSH_CMSG_USER); @@ -407,61 +328,46 @@ user = packet_get_string(&ulen); packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); - setproctitle("%s", user); + if ((style = strchr(user, ':')) != NULL) + *style++ = 0; -#ifdef AFS - /* If machine has AFS, set process authentication group. */ - if (k_hasafs()) { - k_setpag(); - k_unlog(); - } -#endif /* AFS */ + authctxt = authctxt_new(); + authctxt->user = user; + authctxt->style = style; /* Verify that the user is a valid user. */ pw = getpwnam(user); - if (!pw || !allowed_user(pw)) - do_fake_authloop1(user); - xfree(user); + if (pw && allowed_user(pw)) { + authctxt->valid = 1; + pw = pwcopy(pw); + } else { + debug("do_authentication: illegal user %s", user); + pw = NULL; + } + authctxt->pw = pw; - /* Take a copy of the returned structure. */ - memset(&pwcopy, 0, sizeof(pwcopy)); - pwcopy.pw_name = xstrdup(pw->pw_name); - pwcopy.pw_passwd = xstrdup(pw->pw_passwd); - pwcopy.pw_uid = pw->pw_uid; - pwcopy.pw_gid = pw->pw_gid; - pwcopy.pw_dir = xstrdup(pw->pw_dir); - pwcopy.pw_shell = xstrdup(pw->pw_shell); - pw = &pwcopy; + setproctitle("%s", pw ? user : "unknown"); /* * If we are not running as root, the user must have the same uid as * the server. */ - if (getuid() != 0 && pw->pw_uid != getuid()) + if (getuid() != 0 && pw && pw->pw_uid != getuid()) packet_disconnect("Cannot change user when server not running as root."); - debug("Attempting authentication for %.100s.", pw->pw_name); + /* + * Loop until the user has been authenticated or the connection is + * closed, do_authloop() returns only if authentication is successful + */ + do_authloop(authctxt); - /* If the user has no password, accept authentication immediately. */ - if (options.password_authentication && -#ifdef KRB4 - (!options.kerberos_authentication || options.kerberos_or_local_passwd) && -#endif /* KRB4 */ - auth_password(pw, "")) { - /* Authentication with empty password succeeded. */ - log("Login for user %s from %.100s, accepted without authentication.", - pw->pw_name, get_remote_ipaddr()); - } else { - /* Loop until the user has been authenticated or the - connection is closed, do_authloop() returns only if - authentication is successfull */ - do_authloop(pw); - } - /* The user has been authenticated and accepted. */ packet_start(SSH_SMSG_SUCCESS); packet_send(); packet_write_wait(); + + xfree(authctxt->user); + xfree(authctxt); /* Perform session preparation. */ do_authenticated(pw);