struct passwd * getpwnamallow(const char *user) { #ifdef HAVE_LOGIN_CAP extern login_cap_t *lc; #ifdef BSD_AUTH auth_session_t *as; #endif #endif struct passwd *pw; pw = getpwnam(user); if (pw == NULL) { logit("Illegal user %.100s from %.100s", user, get_remote_ipaddr()); #ifdef CONFIG_AMAZON access__attempted(1, user); #endif #ifdef CUSTOM_FAILED_LOGIN record_failed_login(user, "ssh"); #endif return (NULL); } if (!allowed_user(pw)) { #ifdef CONFIG_AMAZON access__attempted(1, user); #endif return (NULL); } #ifdef HAVE_LOGIN_CAP if ((lc = login_getclass(pw->pw_class)) == NULL) { debug("unable to get login class: %s", user); #ifdef CONFIG_AMAZON access__attempted(1, user); #endif return (NULL); } #ifdef BSD_AUTH if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { debug("Approval failure for %s", user); pw = NULL; } if (as != NULL) auth_close(as); #endif #endif if (pw != NULL) return (pwcopy(pw)); return (NULL); }
void auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) { void (*authlog) (const char *fmt,...) = verbose; char *authmsg; if (use_privsep && !mm_is_monitor() && !authctxt->postponed) return; /* Raise logging level */ if (authenticated == 1 || !authctxt->valid || authctxt->failures >= options.max_authtries / 2 || strcmp(method, "password") == 0) authlog = logit; if (authctxt->postponed) authmsg = "Postponed"; else authmsg = authenticated ? "Accepted" : "Failed"; authlog("%s %s for %s%.100s from %.200s port %d%s", authmsg, method, authctxt->valid ? "" : "invalid user ", authctxt->user, get_remote_ipaddr(), get_remote_port(), info); #ifdef CUSTOM_FAILED_LOGIN if (authenticated == 0 && !authctxt->postponed && (strcmp(method, "password") == 0 || strncmp(method, "keyboard-interactive", 20) == 0 || strcmp(method, "challenge-response") == 0)) record_failed_login(authctxt->user, get_canonical_hostname(options.use_dns), "ssh"); # ifdef WITH_AIXAUTHENTICATE if (authenticated) sys_auth_record_login(authctxt->user, get_canonical_hostname(options.use_dns), "ssh", &loginmsg); # endif #endif #ifdef SSH_AUDIT_EVENTS if (authenticated == 0 && !authctxt->postponed) audit_event(audit_classify_auth(method)); #endif #ifdef SECURITY_COUNTS if (strcmp(method, "password") == 0) access__attempted(!authenticated, authctxt->user); #endif }
void auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) { void (*authlog) (const char *fmt,...) = verbose; char *authmsg; /* Raise logging level */ if (authenticated == 1 || !authctxt->valid || authctxt->failures >= AUTH_FAIL_LOG || strcmp(method, "password") == 0) authlog = logit; if (authctxt->postponed) authmsg = "Postponed"; else authmsg = authenticated ? "Accepted" : "Failed"; authlog("%s %s for %s%.100s from %.200s port %d%s", authmsg, method, authctxt->valid ? "" : "illegal user ", authctxt->user, get_remote_ipaddr(), get_remote_port(), info); #ifdef CUSTOM_FAILED_LOGIN if (authenticated == 0 && strcmp(method, "password") == 0) record_failed_login(authctxt->user, "ssh"); #endif #ifdef CONFIG_AMAZON if (strcmp(method, "password") == 0) access__attempted(!authenticated, authctxt->user); #endif }
int main(int argc, char *argv[]) { char *user; char *realpwd, *gotpwd, *cpwd; char *host = NULL; int flag; while ((flag = getopt(argc, argv, "h:")) != EOF) { switch (flag) { case 'h': host = optarg; break; default: fprintf(stderr, "login [OPTION]... [username]\n" "\nBegin a new session on the system\n\n" "Options:\n" "\t-h\t\tName of the remote host for this login.\n" ); } } chdir("/"); if (optind < argc) { user = argv[optind]; } else { printf("login: "******"Password: "******"root") == 0))) realpwd = getoldpass(PATH_OLD_PASSWD); #endif openlog("login", LOG_PID, LOG_AUTHPRIV); if (gotpwd && realpwd #ifdef ONLY_ALLOW_ROOT && strcmp(user, "root") == 0 #endif ) { int good = 0; cpwd = crypt(gotpwd, realpwd); if (strcmp(cpwd, realpwd) == 0) good++; #ifdef OLD_CONFIG_PASSWORDS cpwd = crypt_old(gotpwd, realpwd); if (strcmp(cpwd, realpwd) == 0) good++; #endif #ifdef CONFIG_AMAZON access__attempted(!good, user); #endif if (good) { syslog(LOG_INFO, "Authentication successful for %s from %s\n", user, host ? host : "unknown"); #ifdef EMBED execlp("sh", "sh", NULL); #else execlp("sh", "sh", "-t", NULL); #endif } else { syslog(LOG_ERR, "Authentication attempt failed for %s from %s because: Bad Password\n", user, host ? host : "unknown"); sleep(DELAY_EXIT); } } else { #ifdef CONFIG_AMAZON access__attempted(1, user); #endif syslog(LOG_ERR, "Authentication attempt failed for %s from %s because: Invalid Username\n", user, host ? host : "unknown"); sleep(DELAY_EXIT); } return(0); }
/* * read packets, try to authenticate the user and * return only if authentication is successful */ static void do_authloop(Authctxt *authctxt) { int authenticated = 0; u_int bits; Key *client_host_key; BIGNUM *n; char *client_user, *password; char info[1024]; u_int dlen; u_int ulen; int type = 0; 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 && #if defined(KRB4) || defined(KRB5) (!options.kerberos_authentication || options.kerberos_or_local_passwd) && #endif PRIVSEP(auth_password(authctxt, ""))) { auth_log(authctxt, 1, "without authentication", ""); return; } /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); client_user = NULL; for (;;) { /* default to fail */ authenticated = 0; info[0] = '\0'; /* Get a packet from the client. */ type = packet_read(); /* Process the packet. */ switch (type) { #if defined(KRB4) || defined(KRB5) case SSH_CMSG_AUTH_KERBEROS: if (!options.kerberos_authentication) { verbose("Kerberos authentication disabled."); } else { char *kdata = packet_get_string(&dlen); packet_check_eom(); if (kdata[0] == 4) { /* KRB_PROT_VERSION */ #ifdef KRB4 KTEXT_ST tkt, reply; tkt.length = dlen; if (tkt.length < MAX_KTXT_LEN) memcpy(tkt.dat, kdata, tkt.length); if (PRIVSEP(auth_krb4(authctxt, &tkt, &client_user, &reply))) { authenticated = 1; snprintf(info, sizeof(info), " tktuser %.100s", client_user); packet_start( SSH_SMSG_AUTH_KERBEROS_RESPONSE); packet_put_string((char *) reply.dat, reply.length); packet_send(); packet_write_wait(); } #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 || 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) { verbose("Rhosts authentication disabled."); break; } /* * Get client user name. Note that we just have to * trust the client; this is one reason why rhosts * authentication is insecure. (Another is * IP-spoofing on a local network.) */ client_user = packet_get_string(&ulen); packet_check_eom(); /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ authenticated = auth_rhosts(pw, client_user); snprintf(info, sizeof info, " ruser %.100s", client_user); break; case SSH_CMSG_AUTH_RHOSTS_RSA: if (!options.rhosts_rsa_authentication) { verbose("Rhosts with RSA authentication disabled."); break; } /* * Get client user name. Note that we just have to * trust the client; root on the client machine can * claim to be any user. */ client_user = packet_get_string(&ulen); /* Get the client host key. */ client_host_key = key_new(KEY_RSA1); bits = packet_get_int(); packet_get_bignum(client_host_key->rsa->e); packet_get_bignum(client_host_key->rsa->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->rsa->n), bits); packet_check_eom(); authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); key_free(client_host_key); snprintf(info, sizeof info, " ruser %.100s", client_user); break; case SSH_CMSG_AUTH_RSA: if (!options.rsa_authentication) { verbose("RSA authentication disabled."); break; } /* RSA authentication requested. */ 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; case SSH_CMSG_AUTH_PASSWORD: if (!options.password_authentication) { verbose("Password authentication disabled."); break; } /* * Read user password. It is in plain text, but was * transmitted over the encrypted channel so it is * not visible to an outside observer. */ password = packet_get_string(&dlen); packet_check_eom(); /* Try authentication with the password. */ authenticated = PRIVSEP(auth_password(authctxt, password)); memset(password, 0, strlen(password)); xfree(password); break; case SSH_CMSG_AUTH_TIS: debug("rcvd SSH_CMSG_AUTH_TIS"); 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; } } break; case SSH_CMSG_AUTH_TIS_RESPONSE: debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); if (options.challenge_response_authentication == 1) { char *response = packet_get_string(&dlen); debug("got response '%s'", response); packet_check_eom(); authenticated = verify_response(authctxt, response); memset(response, 'r', dlen); xfree(response); } break; default: /* * Any unknown messages will be ignored (and failure * returned) during authentication. */ 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 _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.", pw == NULL ? -1 : pw->pw_uid); authenticated = 0; } #else /* Special handling for root */ if (!use_privsep && authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed(get_authname(type))) authenticated = 0; #endif #ifdef USE_PAM if (!use_privsep && authenticated && !do_pam_account(pw->pw_name, client_user)) authenticated = 0; #endif #ifdef CONFIG_AMAZON access__attempted(!authenticated, authctxt->user); #endif /* Log before sending the reply */ auth_log(authctxt, authenticated, get_authname(type), info); if (client_user != NULL) { xfree(client_user); client_user = NULL; } if (authenticated) return; if (authctxt->failures++ > AUTH_FAIL_MAX) { packet_disconnect(AUTH_FAIL_MSG, authctxt->user); } packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); } }
/* * read packets, try to authenticate the user and * return only if authentication is successful */ static void do_authloop(Authctxt *authctxt) { int authenticated = 0; char info[1024]; int prev = 0, type = 0; const struct AuthMethod1 *meth; debug("Attempting authentication for %s%.100s.", authctxt->valid ? "" : "invalid user ", authctxt->user); /* If the user has no password, accept authentication immediately. */ if (options.password_authentication && #ifdef KRB5 (!options.kerberos_authentication || options.kerberos_or_local_passwd) && #endif PRIVSEP(auth_password(authctxt, ""))) { #ifdef USE_PAM if (options.use_pam && (PRIVSEP(do_pam_account()))) #endif { auth_log(authctxt, 1, "without authentication", ""); return; } } /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); for (;;) { /* default to fail */ authenticated = 0; info[0] = '\0'; /* Get a packet from the client. */ prev = type; type = packet_read(); /* * If we started challenge-response authentication but the * next packet is not a response to our challenge, release * the resources allocated by get_challenge() (which would * normally have been released by verify_response() had we * received such a response) */ if (prev == SSH_CMSG_AUTH_TIS && type != SSH_CMSG_AUTH_TIS_RESPONSE) abandon_challenge_response(authctxt); if ((meth = lookup_authmethod1(type)) == NULL) { logit("Unknown message during authentication: " "type %d", type); goto skip; } if (!*(meth->enabled)) { verbose("%s authentication disabled.", meth->name); goto skip; } authenticated = meth->method(authctxt, info, sizeof(info)); if (authenticated == -1) continue; /* "postponed" */ #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 _UNICOS 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, authctxt->pw)) { packet_disconnect("Authentication rejected for uid %d.", authctxt->pw == NULL ? -1 : authctxt->pw->pw_uid); authenticated = 0; } #else /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed(meth->name)) { authenticated = 0; # ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED)); # endif } #endif #ifdef USE_PAM if (options.use_pam && authenticated && !PRIVSEP(do_pam_account())) { char *msg; size_t len; error("Access denied for user %s by PAM account " "configuration", authctxt->user); len = buffer_len(&loginmsg); buffer_append(&loginmsg, "\0", 1); msg = buffer_ptr(&loginmsg); /* strip trailing newlines */ if (len > 0) while (len > 0 && msg[--len] == '\n') msg[len] = '\0'; else msg = "Access denied."; packet_disconnect(msg); } #endif skip: #ifdef SECURITY_COUNTS access__attempted(!authenticated, authctxt->user); #endif /* Log before sending the reply */ auth_log(authctxt, authenticated, get_authname(type), info); if (client_user != NULL) { xfree(client_user); client_user = NULL; } if (authenticated) return; if (authctxt->failures++ > options.max_authtries) { #ifdef SSH_AUDIT_EVENTS PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES)); #endif packet_disconnect(AUTH_FAIL_MSG, authctxt->user); } packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); } }
struct passwd * getpwnamallow(const char *user) { #ifdef HAVE_LOGIN_CAP extern login_cap_t *lc; #ifdef BSD_AUTH auth_session_t *as; #endif #endif struct passwd *pw; parse_server_match_config(&options, user, get_canonical_hostname(options.use_dns), get_remote_ipaddr()); #if defined(_AIX) && defined(HAVE_SETAUTHDB) aix_setauthdb(user); #endif pw = getpwnam(user); #if defined(_AIX) && defined(HAVE_SETAUTHDB) aix_restoreauthdb(); #endif #ifdef HAVE_CYGWIN /* * Windows usernames are case-insensitive. To avoid later problems * when trying to match the username, the user is only allowed to * login if the username is given in the same case as stored in the * user database. */ if (pw != NULL && strcmp(user, pw->pw_name) != 0) { logit("Login name %.100s does not match stored username %.100s", user, pw->pw_name); pw = NULL; } #endif if (pw == NULL) { logit("Invalid user %.100s from %.100s", user, get_remote_ipaddr()); #ifdef SECURITY_COUNTS access__attempted(1, user); #endif #ifdef CUSTOM_FAILED_LOGIN record_failed_login(user, get_canonical_hostname(options.use_dns), "ssh"); #endif #ifdef SSH_AUDIT_EVENTS audit_event(SSH_INVALID_USER); #endif /* SSH_AUDIT_EVENTS */ return (NULL); } if (!allowed_user(pw)) { #ifdef SECURITY_COUNTS access__attempted(1, user); #endif return (NULL); } #ifdef HAVE_LOGIN_CAP if ((lc = login_getclass(pw->pw_class)) == NULL) { debug("unable to get login class: %s", user); #ifdef SECURITY_COUNTS access__attempted(1, user); #endif return (NULL); } #ifdef BSD_AUTH if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { debug("Approval failure for %s", user); pw = NULL; } if (as != NULL) auth_close(as); #endif #endif if (pw != NULL) return (pwcopy(pw)); return (NULL); }
/* * read packets, try to authenticate the user and * return only if authentication is successful */ static void do_authloop(Authctxt *authctxt) { int authenticated = 0; u_int bits; Key *client_host_key; BIGNUM *n; char *client_user, *password; char info[1024]; u_int dlen; u_int ulen; int prev, type = 0; 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 KRB5 (!options.kerberos_authentication || options.kerberos_or_local_passwd) && #endif PRIVSEP(auth_password(authctxt, ""))) { auth_log(authctxt, 1, "without authentication", ""); return; } /* Indicate that authentication is needed. */ packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); client_user = NULL; for (;;) { /* default to fail */ authenticated = 0; info[0] = '\0'; /* Get a packet from the client. */ prev = type; type = packet_read(); /* * If we started challenge-response authentication but the * next packet is not a response to our challenge, release * the resources allocated by get_challenge() (which would * normally have been released by verify_response() had we * received such a response) */ if (prev == SSH_CMSG_AUTH_TIS && type != SSH_CMSG_AUTH_TIS_RESPONSE) abandon_challenge_response(authctxt); /* Process the packet. */ switch (type) { case SSH_CMSG_AUTH_RHOSTS_RSA: if (!options.rhosts_rsa_authentication) { verbose("Rhosts with RSA authentication disabled."); break; } /* * Get client user name. Note that we just have to * trust the client; root on the client machine can * claim to be any user. */ client_user = packet_get_string(&ulen); /* Get the client host key. */ client_host_key = key_new(KEY_RSA1); bits = packet_get_int(); packet_get_bignum(client_host_key->rsa->e); packet_get_bignum(client_host_key->rsa->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->rsa->n), bits); packet_check_eom(); authenticated = auth_rhosts_rsa(pw, client_user, client_host_key); key_free(client_host_key); snprintf(info, sizeof info, " ruser %.100s", client_user); break; case SSH_CMSG_AUTH_RSA: if (!options.rsa_authentication) { verbose("RSA authentication disabled."); break; } /* RSA authentication requested. */ 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; case SSH_CMSG_AUTH_PASSWORD: if (!options.password_authentication) { verbose("Password authentication disabled."); break; } /* * Read user password. It is in plain text, but was * transmitted over the encrypted channel so it is * not visible to an outside observer. */ password = packet_get_string(&dlen); packet_check_eom(); /* Try authentication with the password. */ authenticated = PRIVSEP(auth_password(authctxt, password)); memset(password, 0, strlen(password)); xfree(password); break; case SSH_CMSG_AUTH_TIS: debug("rcvd SSH_CMSG_AUTH_TIS"); 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; } } break; case SSH_CMSG_AUTH_TIS_RESPONSE: debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); if (options.challenge_response_authentication == 1) { char *response = packet_get_string(&dlen); packet_check_eom(); authenticated = verify_response(authctxt, response); memset(response, 'r', dlen); xfree(response); } break; default: /* * Any unknown messages will be ignored (and failure * returned) during authentication. */ logit("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 _UNICOS 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.", pw == NULL ? -1 : pw->pw_uid); authenticated = 0; } #else /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed(get_authname(type))) authenticated = 0; #endif #ifdef USE_PAM if (options.use_pam && authenticated && !PRIVSEP(do_pam_account())) authenticated = 0; #endif #ifdef SECURITY_COUNTS access__attempted(!authenticated, authctxt->user); #endif /* Log before sending the reply */ auth_log(authctxt, authenticated, get_authname(type), info); if (client_user != NULL) { xfree(client_user); client_user = NULL; } if (authenticated) return; if (authctxt->failures++ > AUTH_FAIL_MAX) packet_disconnect(AUTH_FAIL_MSG, authctxt->user); packet_start(SSH_SMSG_FAILURE); packet_send(); packet_write_wait(); } }