=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/auth.c,v retrieving revision 1.5 retrieving revision 1.6 diff -u -r1.5 -r1.6 --- src/usr.bin/ssh/auth.c 2000/04/26 20:56:29 1.5 +++ src/usr.bin/ssh/auth.c 2000/04/26 21:28:31 1.6 @@ -5,12 +5,8 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth.c,v 1.5 2000/04/26 20:56:29 markus Exp $"); +RCSID("$OpenBSD: auth.c,v 1.6 2000/04/26 21:28:31 markus Exp $"); -#include -#include -#include - #include "xmalloc.h" #include "rsa.h" #include "ssh.h" @@ -23,17 +19,13 @@ #include "compat.h" #include "channels.h" #include "match.h" + #include "bufaux.h" #include "ssh2.h" #include "auth.h" #include "session.h" #include "dispatch.h" -#include "key.h" -#include "kex.h" -#include "dsa.h" -#include "uidswap.h" -#include "channels.h" /* import */ extern ServerOptions options; @@ -116,820 +108,4 @@ } /* We found no reason not to let this user try to log on... */ return 1; -} - -/* import */ -extern ServerOptions options; -extern char *forced_command; - -/* - * convert ssh auth msg type into description - */ -char * -get_authname(int type) -{ - static char buf[1024]; - switch (type) { - case SSH_CMSG_AUTH_PASSWORD: - return "password"; - case SSH_CMSG_AUTH_RSA: - return "rsa"; - case SSH_CMSG_AUTH_RHOSTS_RSA: - return "rhosts-rsa"; - case SSH_CMSG_AUTH_RHOSTS: - return "rhosts"; -#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; -} - -#define AUTH_FAIL_MAX 6 -#define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) -#define AUTH_FAIL_MSG "Too many authentication failures for %.100s" - -/* - * The user does not exist or access is denied, - * but fake indication that authentication is needed. - */ -void -do_fake_authloop1(char *user) -{ - 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; - RSA *client_host_key; - BIGNUM *n; - char *client_user, *password; - char user[1024]; - unsigned int dlen; - int plen, nlen, elen; - unsigned int ulen; - int type = 0; - void (*authlog) (const char *fmt,...) = verbose; - - /* 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); - - /* Get a packet from the client. */ - type = packet_read(&plen); - - /* Process the packet. */ - switch (type) { -#ifdef AFS - case SSH_CMSG_HAVE_KERBEROS_TGT: - if (!options.kerberos_tgt_passing) { - /* packet_get_all(); */ - 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 %s", pw->pw_name); - 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 { - /* 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 %s", pw->pw_name); - xfree(token_string); - } - continue; -#endif /* AFS */ -#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); - 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); - } - } - break; -#endif /* KRB4 */ - - 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_integrity_check(plen, 4 + ulen, type); - - /* Try to authenticate using /etc/hosts.equiv and - .rhosts. */ - authenticated = auth_rhosts(pw, client_user); - - snprintf(user, sizeof user, " ruser %s", client_user); - xfree(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 = 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"); - bits = packet_get_int(); - packet_get_bignum(client_host_key->e, &elen); - packet_get_bignum(client_host_key->n, &nlen); - - if (bits != BN_num_bits(client_host_key->n)) - error("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); - xfree(client_user); - break; - - case SSH_CMSG_AUTH_RSA: - if (!options.rsa_authentication) { - verbose("RSA authentication disabled."); - break; - } - /* RSA authentication requested. */ - n = BN_new(); - packet_get_bignum(n, &nlen); - packet_integrity_check(plen, nlen, type); - 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_integrity_check(plen, 4 + dlen, type); - - /* Try authentication with the password. */ - authenticated = auth_password(pw, password); - - memset(password, 0, strlen(password)); - 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); - packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); - packet_put_string(skeyinfo, strlen(skeyinfo)); - packet_send(); - packet_write_wait(); - continue; - } - } - break; - case SSH_CMSG_AUTH_TIS_RESPONSE: - debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); - if (options.skey_authentication == 1) { - char *response = packet_get_string(&dlen); - debug("skey response == '%s'", response); - packet_integrity_check(plen, 4 + dlen, type); - authenticated = (skey_haskey(pw->pw_name) == 0 && - skey_passcheck(pw->pw_name, response) != -1); - xfree(response); - } - break; -#else - case SSH_CMSG_AUTH_TIS: - /* TIS Authentication is unsupported */ - log("TIS authentication unsupported."); - break; -#endif - - default: - /* - * Any unknown messages will be ignored (and failure - * returned) during authentication. - */ - log("Unknown message during authentication: type %d", type); - break; - } - - /* - * 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()); - } - } - - /* Raise logging level */ - if (authenticated || - attempt == AUTH_FAIL_LOG || - type == SSH_CMSG_AUTH_PASSWORD) - authlog = log; - - 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); - - /* Send a message indicating that the authentication attempt failed. */ - packet_start(SSH_SMSG_FAILURE); - packet_send(); - packet_write_wait(); - } -} - -/* - * Performs authentication of an incoming connection. Session key has already - * been exchanged and encryption is enabled. - */ -void -do_authentication() -{ - struct passwd *pw, pwcopy; - int plen; - unsigned int ulen; - char *user; - - /* Get the name of the user that we wish to log in as. */ - packet_read_expect(&plen, SSH_CMSG_USER); - - /* Get the user name. */ - user = packet_get_string(&ulen); - packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); - - 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)) - do_fake_authloop1(user); - xfree(user); - - /* 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; - - /* - * If we are not running as root, the user must have the same uid as - * the server. - */ - if (getuid() != 0 && pw->pw_uid != getuid()) - packet_disconnect("Cannot change user when server not running as root."); - - debug("Attempting authentication for %.100s.", pw->pw_name); - - /* 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(); - - /* Perform session preparation. */ - do_authenticated(pw); -} - -/* import */ -extern ServerOptions options; -extern unsigned char *session_id2; -extern int session_id2_len; - -/* protocol */ - -void input_service_request(int type, int plen); -void input_userauth_request(int type, int plen); -void protocol_error(int type, int plen); - -/* auth */ -int ssh2_auth_none(struct passwd *pw); -int ssh2_auth_password(struct passwd *pw); -int ssh2_auth_pubkey(struct passwd *pw, unsigned char *raw, unsigned int rlen); - -/* helper */ -struct passwd* auth_set_user(char *u, char *s); -int user_dsa_key_allowed(struct passwd *pw, Key *key); - -typedef struct Authctxt Authctxt; -struct Authctxt { - char *user; - char *service; - struct passwd pw; - int valid; -}; -static Authctxt *authctxt = NULL; -static int userauth_success = 0; - -/* set and get current user */ - -struct passwd* -auth_get_user(void) -{ - return (authctxt != NULL && authctxt->valid) ? &authctxt->pw : NULL; -} - -struct passwd* -auth_set_user(char *u, char *s) -{ - struct passwd *pw, *copy; - - if (authctxt == NULL) { - authctxt = xmalloc(sizeof(*authctxt)); - authctxt->valid = 0; - authctxt->user = xstrdup(u); - authctxt->service = xstrdup(s); - setproctitle("%s", u); - pw = getpwnam(u); - if (!pw || !allowed_user(pw)) { - log("auth_set_user: bad user %s", u); - return NULL; - } - copy = &authctxt->pw; - memset(copy, 0, sizeof(*copy)); - copy->pw_name = xstrdup(pw->pw_name); - copy->pw_passwd = xstrdup(pw->pw_passwd); - copy->pw_uid = pw->pw_uid; - copy->pw_gid = pw->pw_gid; - copy->pw_dir = xstrdup(pw->pw_dir); - copy->pw_shell = xstrdup(pw->pw_shell); - authctxt->valid = 1; - } else { - if (strcmp(u, authctxt->user) != 0 || - strcmp(s, authctxt->service) != 0) { - log("auth_set_user: missmatch: (%s,%s)!=(%s,%s)", - u, s, authctxt->user, authctxt->service); - return NULL; - } - } - return auth_get_user(); -} - -/* - * loop until userauth_success == TRUE - */ - -void -do_authentication2() -{ - dispatch_init(&protocol_error); - dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request); - dispatch_run(DISPATCH_BLOCK, &userauth_success); - do_authenticated2(); -} - -void -protocol_error(int type, int plen) -{ - log("auth: protocol error: type %d plen %d", type, plen); - packet_start(SSH2_MSG_UNIMPLEMENTED); - packet_put_int(0); - packet_send(); - packet_write_wait(); -} - -void -input_service_request(int type, int plen) -{ - unsigned int len; - int accept = 0; - char *service = packet_get_string(&len); - packet_done(); - - if (strcmp(service, "ssh-userauth") == 0) { - if (!userauth_success) { - accept = 1; - /* now we can handle user-auth requests */ - dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request); - } - } - /* XXX all other service requests are denied */ - - if (accept) { - packet_start(SSH2_MSG_SERVICE_ACCEPT); - packet_put_cstring(service); - packet_send(); - packet_write_wait(); - } else { - debug("bad service request %s", service); - packet_disconnect("bad service request %s", service); - } - xfree(service); -} - -void -input_userauth_request(int type, int plen) -{ - static int try = 0; - unsigned int len, rlen; - int authenticated = 0; - char *raw, *user, *service, *method; - struct passwd *pw; - - if (++try == AUTH_FAIL_MAX) - packet_disconnect("too many failed userauth_requests"); - - raw = packet_get_raw(&rlen); - if (plen != rlen) - fatal("plen != rlen"); - user = packet_get_string(&len); - service = packet_get_string(&len); - method = packet_get_string(&len); - debug("userauth-request for user %s service %s method %s", user, service, method); - - /* XXX we only allow the ssh-connection service */ - pw = auth_set_user(user, service); - if (pw && strcmp(service, "ssh-connection")==0) { - if (strcmp(method, "none") == 0) { - authenticated = ssh2_auth_none(pw); - } else if (strcmp(method, "password") == 0) { - authenticated = ssh2_auth_password(pw); - } else if (strcmp(method, "publickey") == 0) { - authenticated = ssh2_auth_pubkey(pw, raw, rlen); - } - } - /* XXX check if other auth methods are needed */ - if (authenticated == 1) { - log("userauth success for %s method %s", user, method); - /* turn off userauth */ - dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error); - packet_start(SSH2_MSG_USERAUTH_SUCCESS); - packet_send(); - packet_write_wait(); - /* now we can break out */ - userauth_success = 1; - } else if (authenticated == 0) { - log("userauth failure for %s method %s", user, method); - packet_start(SSH2_MSG_USERAUTH_FAILURE); - packet_put_cstring("publickey,password"); /* XXX dynamic */ - packet_put_char(0); /* XXX partial success, unused */ - packet_send(); - packet_write_wait(); - } else { - log("userauth postponed for %s method %s", user, method); - } - xfree(service); - xfree(user); - xfree(method); -} - -int -ssh2_auth_none(struct passwd *pw) -{ - packet_done(); - return auth_password(pw, ""); -} -int -ssh2_auth_password(struct passwd *pw) -{ - char *password; - int authenticated = 0; - int change; - unsigned int len; - change = packet_get_char(); - if (change) - log("password change not supported"); - password = packet_get_string(&len); - packet_done(); - if (auth_password(pw, password)) - authenticated = 1; - memset(password, 0, len); - xfree(password); - return authenticated; -} - -int -ssh2_auth_pubkey(struct passwd *pw, unsigned char *raw, unsigned int rlen) -{ - Buffer b; - Key *key; - char *pkalg, *pkblob, *sig; - unsigned int alen, blen, slen; - int have_sig; - int authenticated = 0; - - have_sig = packet_get_char(); - pkalg = packet_get_string(&alen); - if (strcmp(pkalg, KEX_DSS) != 0) { - xfree(pkalg); - log("bad pkalg %s", pkalg); /*XXX*/ - return 0; - } - pkblob = packet_get_string(&blen); - key = dsa_key_from_blob(pkblob, blen); - - if (have_sig && key != NULL) { - sig = packet_get_string(&slen); - packet_done(); - buffer_init(&b); - buffer_append(&b, session_id2, session_id2_len); - buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); - if (slen + 4 > rlen) - fatal("bad rlen/slen"); - buffer_append(&b, raw, rlen - slen - 4); -#ifdef DEBUG_DSS - buffer_dump(&b); -#endif - /* test for correct signature */ - if (user_dsa_key_allowed(pw, key) && - dsa_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1) - authenticated = 1; - buffer_clear(&b); - xfree(sig); - } else if (!have_sig && key != NULL) { - packet_done(); - debug("test key..."); - /* test whether pkalg/pkblob are acceptable */ - /* XXX fake reply and always send PK_OK ? */ - if (user_dsa_key_allowed(pw, key)) { - packet_start(SSH2_MSG_USERAUTH_PK_OK); - packet_put_string(pkalg, alen); - packet_put_string(pkblob, blen); - packet_send(); - packet_write_wait(); - authenticated = -1; - } - } - xfree(pkalg); - xfree(pkblob); - return authenticated; -} - -/* return 1 if user allows given key */ -int -user_dsa_key_allowed(struct passwd *pw, Key *key) -{ - char line[8192], file[1024]; - int found_key = 0; - unsigned int bits = -1; - FILE *f; - unsigned long linenum = 0; - struct stat st; - Key *found; - - /* Temporarily use the user's uid. */ - temporarily_use_uid(pw->pw_uid); - - /* The authorized keys. */ - snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, - SSH_USER_PERMITTED_KEYS2); - - /* Fail quietly if file does not exist */ - if (stat(file, &st) < 0) { - /* Restore the privileged uid. */ - restore_uid(); - return 0; - } - /* Open the file containing the authorized keys. */ - f = fopen(file, "r"); - if (!f) { - /* Restore the privileged uid. */ - restore_uid(); - packet_send_debug("Could not open %.900s for reading.", file); - packet_send_debug("If your home is on an NFS volume, it may need to be world-readable."); - return 0; - } - if (options.strict_modes) { - int fail = 0; - char buf[1024]; - /* Check open file in order to avoid open/stat races */ - if (fstat(fileno(f), &st) < 0 || - (st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0) { - snprintf(buf, sizeof buf, "DSA authentication refused for %.100s: " - "bad ownership or modes for '%s'.", pw->pw_name, file); - fail = 1; - } else { - /* Check path to SSH_USER_PERMITTED_KEYS */ - int i; - static const char *check[] = { - "", SSH_USER_DIR, NULL - }; - for (i = 0; check[i]; i++) { - snprintf(line, sizeof line, "%.500s/%.100s", - pw->pw_dir, check[i]); - if (stat(line, &st) < 0 || - (st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0) { - snprintf(buf, sizeof buf, - "DSA authentication refused for %.100s: " - "bad ownership or modes for '%s'.", - pw->pw_name, line); - fail = 1; - break; - } - } - } - if (fail) { - log(buf); - fclose(f); - restore_uid(); - return 0; - } - } - found_key = 0; - found = key_new(KEY_DSA); - - while (fgets(line, sizeof(line), f)) { - char *cp; - linenum++; - /* Skip leading whitespace, empty and comment lines. */ - for (cp = line; *cp == ' ' || *cp == '\t'; cp++) - ; - if (!*cp || *cp == '\n' || *cp == '#') - continue; - bits = key_read(found, &cp); - if (bits == 0) - continue; - if (key_equal(found, key)) { - found_key = 1; - debug("matching key found: file %s, line %ld", - file, linenum); - break; - } - } - restore_uid(); - fclose(f); - key_free(found); - return found_key; }