diff options
Diffstat (limited to 'auth1.c')
-rw-r--r-- | auth1.c | 216 |
1 files changed, 88 insertions, 128 deletions
@@ -10,7 +10,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth1.c,v 1.10 2001/01/07 19:06:25 markus Exp $"); +RCSID("$OpenBSD: auth1.c,v 1.11 2001/01/18 16:59:59 markus Exp $"); #ifdef HAVE_OSF_SIA # include <sia.h> @@ -56,41 +56,53 @@ get_authname(int type) 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; } /* - * read packets and try to authenticate local user 'luser'. - * return if authentication is successful. not that pw == NULL - * if the user does not exists or is not allowed to login. - * each auth method has to 'fake' authentication for nonexisting - * users. + * read packets, try to authenticate the user and + * return only if authentication is successful */ void -do_authloop(struct passwd * pw, char *luser) +do_authloop(Authctxt *authctxt) { int authenticated = 0; - int attempt = 0; u_int bits; RSA *client_host_key; BIGNUM *n; char *client_user, *password; - char user[1024]; + char info[1024]; u_int dlen; int plen, nlen, elen; 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 +#ifdef USE_PAM /* ISSUE: Right?? */ + auth_pam_password(pw, password)) { +#else + auth_password(pw, "")) { +#endif + auth_log(authctxt, 1, "without authentication", ""); + return; + } /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); @@ -99,11 +111,11 @@ do_authloop(struct passwd * pw, char *luser) client_user = NULL; - for (attempt = 1;; attempt++) { + for (;;) { /* default to fail */ authenticated = 0; - strlcpy(user, "", sizeof user); + info[0] = '\0'; /* Get a packet from the client. */ type = packet_read(&plen); @@ -120,7 +132,7 @@ do_authloop(struct passwd * pw, char *luser) 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", luser); + verbose("Kerberos tgt REFUSED for %.100s", authctxt->user); xfree(tgt); } continue; @@ -134,7 +146,7 @@ do_authloop(struct passwd * pw, char *luser) 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", luser); + verbose("AFS token REFUSED for %.100s", authctxt->user); xfree(token_string); } continue; @@ -142,7 +154,6 @@ do_authloop(struct passwd * pw, char *luser) #ifdef KRB4 case SSH_CMSG_AUTH_KERBEROS: if (!options.kerberos_authentication) { - /* packet_get_all(); */ verbose("Kerberos authentication disabled."); break; } else { @@ -152,17 +163,17 @@ do_authloop(struct passwd * pw, char *luser) 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); - - if (pw != NULL) { + 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(user, sizeof user, " tktuser %s", tkt_user); + snprintf(info, sizeof info, + " tktuser %.100s", tkt_user); xfree(tkt_user); } } + xfree(kdata); } break; #endif /* KRB4 */ @@ -184,7 +195,7 @@ do_authloop(struct passwd * pw, char *luser) /* 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); break; case SSH_CMSG_AUTH_RHOSTS_RSA: @@ -219,7 +230,7 @@ do_authloop(struct passwd * pw, char *luser) 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); break; case SSH_CMSG_AUTH_RSA: @@ -267,22 +278,19 @@ do_authloop(struct passwd * pw, char *luser) xfree(password); break; -#ifdef SKEY +#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 *skeyinfo = NULL; - if (pw != NULL) - skeyinfo = skey_keyinfo(pw->pw_name); - if (skeyinfo == NULL) { - debug("generating fake skeyinfo for %.100s.", luser); - skeyinfo = skey_fake_keyinfo(luser); - } - if (skeyinfo != NULL) { - /* we send our s/key- in tis-challenge messages */ - debug("sending challenge '%s'", skeyinfo); + char *challenge = get_challenge(authctxt, authctxt->style); + if (challenge != NULL) { + debug("sending challenge '%s'", challenge); packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_cstring(skeyinfo); + packet_put_cstring(challenge); packet_send(); packet_write_wait(); continue; @@ -293,20 +301,14 @@ do_authloop(struct passwd * pw, char *luser) debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); if (options.skey_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 = (pw != NULL && - 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 +#endif /* ISSUE: End of wrong SKEY defines */ default: /* @@ -316,10 +318,11 @@ do_authloop(struct passwd * pw, char *luser) log("Unknown message during authentication: type %d", type); break; } - if (authenticated && pw == NULL) - fatal("internal error: authenticated for pw == NULL"); + if (!authctxt->valid && authenticated) + fatal("INTERNAL ERROR: authenticated invalid user %s", + authctxt->user); -#ifdef HAVE_CYGWIN +#ifdef HAVE_CYGWIN /* ISSUE: Right place? */ if (authenticated && !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) { packet_disconnect("Authentication rejected for uid %d.", @@ -328,41 +331,18 @@ do_authloop(struct passwd * pw, char *luser) } #endif - /* - * 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->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()); - } - } - - /* Raise logging level */ - if (authenticated || - attempt == AUTH_FAIL_LOG || - type == SSH_CMSG_AUTH_PASSWORD) - authlog = log; - - authlog("%s %s for %s%.100s from %.200s port %d%s", - authenticated ? "Accepted" : "Failed", - get_authname(type), - pw ? "" : "illegal user ", - pw && pw->pw_uid == 0 ? "ROOT" : luser, - get_remote_ipaddr(), - get_remote_port(), - user); + /* Special handling for root */ + if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed()) + authenticated = 0; -#ifdef USE_PAM +#ifdef USE_PAM /* ISSUE: Right place? */ if (authenticated && !do_pam_account(pw->pw_name, client_user)) authenticated = 0; #endif + /* Log before sending the reply */ + auth_log(authctxt, authenticated, get_authname(type), info); + if (client_user != NULL) { xfree(client_user); client_user = NULL; @@ -371,14 +351,13 @@ do_authloop(struct passwd * pw, char *luser) if (authenticated) return; - if (attempt > AUTH_FAIL_MAX) { + if (authctxt->failures++ > AUTH_FAIL_MAX) { #ifdef WITH_AIXAUTHENTICATE loginfailed(user,get_canonical_hostname(),"ssh"); #endif /* WITH_AIXAUTHENTICATE */ - packet_disconnect(AUTH_FAIL_MSG, luser); + 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(); @@ -392,10 +371,11 @@ do_authloop(struct passwd * pw, char *luser) void do_authentication() { - struct passwd *pw, pwcopy; + Authctxt *authctxt; + struct passwd *pw; int plen; u_int ulen; - char *user; + char *user, *style = NULL; /* Get the name of the user that we wish to log in as. */ packet_read_expect(&plen, SSH_CMSG_USER); @@ -404,6 +384,13 @@ do_authentication() user = packet_get_string(&ulen); packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); + if ((style = strchr(user, ':')) != NULL) + *style++ = 0; + + authctxt = authctxt_new(); + authctxt->user = user; + authctxt->style = style; + setproctitle("%s", user); #ifdef AFS @@ -417,21 +404,13 @@ do_authentication() /* Verify that the user is a valid user. */ pw = getpwnam(user); if (pw && allowed_user(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; -#ifdef HAVE_PW_CLASS_IN_PASSWD - pwcopy.pw_class = xstrdup(pw->pw_class); -#endif - pwcopy.pw_dir = xstrdup(pw->pw_dir); - pwcopy.pw_shell = xstrdup(pw->pw_shell); - pw = &pwcopy; + authctxt->valid = 1; + pw = pwcopy(pw); } else { + debug("do_authentication: illegal user %s", user); pw = NULL; } + authctxt->pw = pw; #ifdef USE_PAM if (pw) @@ -447,44 +426,25 @@ do_authentication() packet_disconnect("Cannot change user when server not running as root."); #endif - debug("Attempting authentication for %s%.100s.", pw ? "" : "illegal user ", 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 /* KRB4 */ -#ifdef USE_PAM - auth_pam_password(pw, "")) { -#elif defined(HAVE_OSF_SIA) - (sia_validate_user(NULL, saved_argc, saved_argv, - get_canonical_hostname(), pw->pw_name, NULL, 0, - NULL, "") == SIASUCCESS)) { -#else /* !HAVE_OSF_SIA && !USE_PAM */ - auth_password(pw, "")) { -#endif /* USE_PAM */ - /* Authentication with empty password succeeded. */ - log("Login for user %s from %.100s, accepted without authentication.", - user, get_remote_ipaddr()); - } else { - /* Loop until the user has been authenticated or the - connection is closed, do_authloop() returns only if - authentication is successful */ - do_authloop(pw, user); - } - if (pw == NULL) - fatal("internal error, authentication successful for user '%.100s'", user); + /* + * 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. */ packet_start(SSH_SMSG_SUCCESS); packet_send(); packet_write_wait(); + #ifdef WITH_AIXAUTHENTICATE /* We don't have a pty yet, so just label the line as "ssh" */ - if (loginsuccess(user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0) + if (loginsuccess(authctxt->user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0) aixloginmsg = NULL; #endif /* WITH_AIXAUTHENTICATE */ - xfree(user); + + xfree(authctxt->user); + xfree(authctxt); /* Perform session preparation. */ do_authenticated(pw); |