X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/3c418020f5ac42bafadf12ac9f9941fa2c6cfbc6..ef51930f93f523426b6c383a1802061fbede93be:/auth1.c diff --git a/auth1.c b/auth1.c index 2df2de89..676c8a66 100644 --- a/auth1.c +++ b/auth1.c @@ -10,40 +10,30 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth1.c,v 1.11 2001/01/18 16:59:59 markus Exp $"); - -#ifdef HAVE_OSF_SIA -# include -# include -#endif +RCSID("$OpenBSD: auth1.c,v 1.43 2002/09/09 06:48:06 itojun Exp $"); #include "xmalloc.h" #include "rsa.h" -#include "ssh.h" +#include "ssh1.h" #include "packet.h" #include "buffer.h" #include "mpaux.h" +#include "log.h" #include "servconf.h" #include "compat.h" #include "auth.h" +#include "channels.h" #include "session.h" +#include "uidswap.h" +#include "monitor_wrap.h" /* import */ extern ServerOptions options; -extern char *forced_command; - -#ifdef WITH_AIXAUTHENTICATE -extern char *aixloginmsg; -#endif /* WITH_AIXAUTHENTICATE */ -#ifdef HAVE_OSF_SIA -extern int saved_argc; -extern char **saved_argv; -#endif /* HAVE_OSF_SIA */ /* * convert ssh auth msg type into description */ -char * +static char * get_authname(int type) { static char buf[1024]; @@ -59,7 +49,7 @@ get_authname(int type) case SSH_CMSG_AUTH_TIS: case SSH_CMSG_AUTH_TIS_RESPONSE: return "challenge-response"; -#ifdef KRB4 +#if defined(KRB4) || defined(KRB5) case SSH_CMSG_AUTH_KERBEROS: return "kerberos"; #endif @@ -72,34 +62,29 @@ get_authname(int type) * read packets, try to authenticate the user and * return only if authentication is successful */ -void +static void do_authloop(Authctxt *authctxt) { int authenticated = 0; u_int bits; - RSA *client_host_key; + Key *client_host_key; BIGNUM *n; char *client_user, *password; char info[1024]; u_int dlen; - int plen, nlen, elen; u_int ulen; int type = 0; struct passwd *pw = authctxt->pw; debug("Attempting authentication for %s%.100s.", - authctxt->valid ? "" : "illegal user ", authctxt->user); + authctxt->valid ? "" : "illegal user ", authctxt->user); /* If the user has no password, accept authentication immediately. */ if (options.password_authentication && -#ifdef KRB4 +#if defined(KRB4) || defined(KRB5) (!options.kerberos_authentication || options.kerberos_or_local_passwd) && #endif -#ifdef USE_PAM - auth_pam_password(pw, password)) { -#else - auth_password(pw, "")) { -#endif + PRIVSEP(auth_password(authctxt, ""))) { auth_log(authctxt, 1, "without authentication", ""); return; } @@ -118,65 +103,76 @@ do_authloop(Authctxt *authctxt) info[0] = '\0'; /* Get a packet from the client. */ - type = packet_read(&plen); + type = packet_read(); /* Process the packet. */ switch (type) { -#ifdef AFS - case SSH_CMSG_HAVE_KERBEROS_TGT: - if (!options.kerberos_tgt_passing) { - verbose("Kerberos tgt passing disabled."); - break; - } else { - /* Accept Kerberos tgt. */ - char *tgt = packet_get_string(&dlen); - packet_integrity_check(plen, 4 + dlen, type); - if (!auth_kerberos_tgt(pw, tgt)) - verbose("Kerberos tgt REFUSED for %.100s", authctxt->user); - xfree(tgt); - } - continue; - case SSH_CMSG_HAVE_AFS_TOKEN: - if (!options.afs_token_passing || !k_hasafs()) { - verbose("AFS token passing disabled."); - break; - } else { - /* Accept AFS token. */ - 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 %.100s", authctxt->user); - xfree(token_string); - } - continue; -#endif /* AFS */ -#ifdef KRB4 +#if defined(KRB4) || defined(KRB5) case SSH_CMSG_AUTH_KERBEROS: if (!options.kerberos_authentication) { verbose("Kerberos authentication disabled."); - break; } else { - /* Try Kerberos v4 authentication. */ - KTEXT_ST auth; - char *tkt_user = NULL; - char *kdata = packet_get_string((u_int *) &auth.length); - packet_integrity_check(plen, 4 + auth.length, type); - - 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); + char *kdata = packet_get_string(&dlen); + packet_check_eom(); + + if (kdata[0] == 4) { /* KRB_PROT_VERSION */ +#ifdef KRB4 + KTEXT_ST tkt; + + tkt.length = dlen; + if (tkt.length < MAX_KTXT_LEN) + memcpy(tkt.dat, kdata, tkt.length); + + if (auth_krb4(authctxt, &tkt, &client_user)) { + authenticated = 1; + snprintf(info, sizeof(info), + " tktuser %.100s", + client_user); } +#endif /* KRB4 */ + } else { +#ifdef KRB5 + krb5_data tkt, reply; + tkt.length = dlen; + tkt.data = kdata; + + if (PRIVSEP(auth_krb5(authctxt, &tkt, + &client_user, &reply))) { + authenticated = 1; + snprintf(info, sizeof(info), + " tktuser %.100s", + client_user); + + /* Send response to client */ + packet_start( + SSH_SMSG_AUTH_KERBEROS_RESPONSE); + packet_put_string((char *) + reply.data, reply.length); + packet_send(); + packet_write_wait(); + + if (reply.length) + xfree(reply.data); + } +#endif /* KRB5 */ } xfree(kdata); } break; -#endif /* KRB4 */ +#endif /* KRB4 || KRB5 */ + +#if defined(AFS) || defined(KRB5) + /* XXX - punt on backward compatibility here. */ + case SSH_CMSG_HAVE_KERBEROS_TGT: + packet_send_debug("Kerberos TGT passing disabled before authentication."); + break; +#ifdef AFS + case SSH_CMSG_HAVE_AFS_TOKEN: + packet_send_debug("AFS token passing disabled before authentication."); + break; +#endif /* AFS */ +#endif /* AFS || KRB5 */ case SSH_CMSG_AUTH_RHOSTS: if (!options.rhosts_authentication) { @@ -190,7 +186,7 @@ do_authloop(Authctxt *authctxt) * IP-spoofing on a local network.) */ client_user = packet_get_string(&ulen); - packet_integrity_check(plen, 4 + ulen, type); + packet_check_eom(); /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ authenticated = auth_rhosts(pw, client_user); @@ -211,24 +207,20 @@ do_authloop(Authctxt *authctxt) client_user = packet_get_string(&ulen); /* Get the client host key. */ - client_host_key = RSA_new(); - if (client_host_key == NULL) - fatal("RSA_new failed"); - client_host_key->e = BN_new(); - client_host_key->n = BN_new(); - if (client_host_key->e == NULL || client_host_key->n == NULL) - fatal("BN_new failed"); + client_host_key = key_new(KEY_RSA1); bits = packet_get_int(); - packet_get_bignum(client_host_key->e, &elen); - packet_get_bignum(client_host_key->n, &nlen); + packet_get_bignum(client_host_key->rsa->e); + packet_get_bignum(client_host_key->rsa->n); - if (bits != BN_num_bits(client_host_key->n)) + if (bits != BN_num_bits(client_host_key->rsa->n)) 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); + "actual %d, announced %d", + BN_num_bits(client_host_key->rsa->n), bits); + packet_check_eom(); - authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); - RSA_free(client_host_key); + authenticated = auth_rhosts_rsa(pw, client_user, + client_host_key); + key_free(client_host_key); snprintf(info, sizeof info, " ruser %.100s", client_user); break; @@ -239,9 +231,10 @@ do_authloop(Authctxt *authctxt) break; } /* RSA authentication requested. */ - n = BN_new(); - packet_get_bignum(n, &nlen); - packet_integrity_check(plen, nlen, type); + if ((n = BN_new()) == NULL) + fatal("do_authloop: BN_new failed"); + packet_get_bignum(n); + packet_check_eom(); authenticated = auth_rsa(pw, n); BN_clear_free(n); break; @@ -257,40 +250,24 @@ do_authloop(Authctxt *authctxt) * not visible to an outside observer. */ password = packet_get_string(&dlen); - packet_integrity_check(plen, 4 + dlen, type); + packet_check_eom(); -#ifdef USE_PAM - /* Do PAM auth with password */ - authenticated = auth_pam_password(pw, password); -#elif defined(HAVE_OSF_SIA) - /* Do SIA auth with password */ - if (sia_validate_user(NULL, saved_argc, saved_argv, - get_canonical_hostname(), pw->pw_name, NULL, 0, - NULL, password) == SIASUCCESS) { - authenticated = 1; - } -#else /* !USE_PAM && !HAVE_OSF_SIA */ - /* Try authentication with the password. */ - authenticated = auth_password(pw, password); -#endif /* USE_PAM */ + /* Try authentication with the password. */ + authenticated = PRIVSEP(auth_password(authctxt, password)); memset(password, 0, strlen(password)); xfree(password); break; -#ifdef SKEY /* ISSUE: Is this right? we don't define - having skey_authentication in - servconf.h by default so I assume - we need to deal with this via #ifdef - in some reasonable way */ case SSH_CMSG_AUTH_TIS: debug("rcvd SSH_CMSG_AUTH_TIS"); - if (options.skey_authentication == 1) { - char *challenge = get_challenge(authctxt, authctxt->style); + if (options.challenge_response_authentication == 1) { + char *challenge = get_challenge(authctxt); if (challenge != NULL) { debug("sending challenge '%s'", challenge); packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); packet_put_cstring(challenge); + xfree(challenge); packet_send(); packet_write_wait(); continue; @@ -299,16 +276,15 @@ do_authloop(Authctxt *authctxt) break; case SSH_CMSG_AUTH_TIS_RESPONSE: debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); - if (options.skey_authentication == 1) { + if (options.challenge_response_authentication == 1) { char *response = packet_get_string(&dlen); debug("got response '%s'", response); - packet_integrity_check(plen, 4 + dlen, type); + packet_check_eom(); authenticated = verify_response(authctxt, response); memset(response, 'r', dlen); xfree(response); } break; -#endif /* ISSUE: End of wrong SKEY defines */ default: /* @@ -318,24 +294,42 @@ do_authloop(Authctxt *authctxt) log("Unknown message during authentication: type %d", type); break; } +#ifdef BSD_AUTH + if (authctxt->as) { + auth_close(authctxt->as); + authctxt->as = NULL; + } +#endif if (!authctxt->valid && authenticated) fatal("INTERNAL ERROR: authenticated invalid user %s", authctxt->user); -#ifdef HAVE_CYGWIN /* ISSUE: Right place? */ - if (authenticated && - !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) { +#ifdef _UNICOS + if (type == SSH_CMSG_AUTH_PASSWORD && !authenticated) + cray_login_failure(authctxt->user, IA_UDBERR); + if (authenticated && cray_access_denied(authctxt->user)) { + authenticated = 0; + fatal("Access denied for user %s.",authctxt->user); + } +#endif /* _UNICOS */ + +#ifdef HAVE_CYGWIN + if (authenticated && + !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) { packet_disconnect("Authentication rejected for uid %d.", - (int)pw->pw_uid); + pw == NULL ? -1 : pw->pw_uid); authenticated = 0; } #else /* Special handling for root */ - if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed()) + if (!use_privsep && + authenticated && authctxt->pw->pw_uid == 0 && + !auth_root_allowed(get_authname(type))) authenticated = 0; #endif -#ifdef USE_PAM - if (authenticated && !do_pam_account(pw->pw_name, client_user)) +#ifdef USE_PAM + if (!use_privsep && authenticated && + !do_pam_account(pw->pw_name, client_user)) authenticated = 0; #endif @@ -350,10 +344,7 @@ do_authloop(Authctxt *authctxt) if (authenticated) return; - if (authctxt->failures++ > AUTH_FAIL_MAX) { -#ifdef WITH_AIXAUTHENTICATE - loginfailed(user,get_canonical_hostname(),"ssh"); -#endif /* WITH_AIXAUTHENTICATE */ + if (authctxt->failures++ > AUTH_FAIL_MAX) { packet_disconnect(AUTH_FAIL_MSG, authctxt->user); } @@ -367,53 +358,48 @@ do_authloop(Authctxt *authctxt) * Performs authentication of an incoming connection. Session key has already * been exchanged and encryption is enabled. */ -void -do_authentication() +Authctxt * +do_authentication(void) { Authctxt *authctxt; - struct passwd *pw; - int plen; 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); + packet_read_expect(SSH_CMSG_USER); /* Get the user name. */ user = packet_get_string(&ulen); - packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); + packet_check_eom(); if ((style = strchr(user, ':')) != NULL) - *style++ = 0; + *style++ = '\0'; + +#ifdef KRB5 + /* XXX - SSH.com Kerberos v5 braindeath. */ + if ((datafellows & SSH_BUG_K5USER) && + options.kerberos_authentication) { + char *p; + if ((p = strchr(user, '@')) != NULL) + *p = '\0'; + } +#endif authctxt = authctxt_new(); authctxt->user = user; authctxt->style = style; - setproctitle("%s", user); - -#ifdef AFS - /* If machine has AFS, set process authentication group. */ - if (k_hasafs()) { - k_setpag(); - k_unlog(); - } -#endif /* AFS */ - /* Verify that the user is a valid user. */ - pw = getpwnam(user); - if (pw && allowed_user(pw)) { + if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) authctxt->valid = 1; - pw = pwcopy(pw); - } else { + else debug("do_authentication: illegal user %s", user); - pw = NULL; - } - authctxt->pw = pw; + + setproctitle("%s%s", authctxt->pw ? user : "unknown", + use_privsep ? " [net]" : ""); #ifdef USE_PAM - if (pw) - start_pam(user); + PRIVSEP(start_pam(authctxt->pw == NULL ? "NOUSER" : user)); #endif /* @@ -421,14 +407,15 @@ do_authentication() * the server. (Unless you are running Windows) */ #ifndef HAVE_CYGWIN - if (getuid() != 0 && pw && pw->pw_uid != getuid()) + if (!use_privsep && getuid() != 0 && authctxt->pw && + authctxt->pw->pw_uid != getuid()) packet_disconnect("Cannot change user when server not running as root."); #endif /* - * Loop until the user has been authenticated or the connection is - * closed, do_authloop() returns only if authentication is successful - */ + * Loop until the user has been authenticated or the connection is + * closed, do_authloop() returns only if authentication is successful + */ do_authloop(authctxt); /* The user has been authenticated and accepted. */ @@ -436,15 +423,5 @@ do_authentication() packet_send(); packet_write_wait(); -#ifdef WITH_AIXAUTHENTICATE - /* We don't have a pty yet, so just label the line as "ssh" */ - if (loginsuccess(authctxt->user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0) - aixloginmsg = NULL; -#endif /* WITH_AIXAUTHENTICATE */ - - xfree(authctxt->user); - xfree(authctxt); - - /* Perform session preparation. */ - do_authenticated(pw); + return (authctxt); }