=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/auth2.c,v retrieving revision 1.56 retrieving revision 1.56.2.1 diff -u -r1.56 -r1.56.2.1 --- src/usr.bin/ssh/auth2.c 2001/04/19 00:05:11 1.56 +++ src/usr.bin/ssh/auth2.c 2001/09/27 19:03:54 1.56.2.1 @@ -23,7 +23,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth2.c,v 1.56 2001/04/19 00:05:11 markus Exp $"); +RCSID("$OpenBSD: auth2.c,v 1.56.2.1 2001/09/27 19:03:54 jason Exp $"); #include @@ -51,6 +51,7 @@ #include "hostfile.h" #include "canohost.h" #include "tildexpand.h" +#include "match.h" /* import */ extern ServerOptions options; @@ -69,26 +70,23 @@ /* protocol */ -void input_service_request(int type, int plen, void *ctxt); -void input_userauth_request(int type, int plen, void *ctxt); -void protocol_error(int type, int plen, void *ctxt); +static void input_service_request(int, int, void *); +static void input_userauth_request(int, int, void *); +static void protocol_error(int, int, void *); /* helper */ -Authmethod *authmethod_lookup(const char *name); -char *authmethods_get(void); -int user_key_allowed(struct passwd *pw, Key *key); -int -hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost, - Key *key); +static Authmethod *authmethod_lookup(const char *); +static char *authmethods_get(void); +static int user_key_allowed(struct passwd *, Key *); +static int hostbased_key_allowed(struct passwd *, const char *, char *, Key *); /* auth */ -void userauth_banner(void); -void userauth_reply(Authctxt *authctxt, int authenticated); -int userauth_none(Authctxt *authctxt); -int userauth_passwd(Authctxt *authctxt); -int userauth_pubkey(Authctxt *authctxt); -int userauth_hostbased(Authctxt *authctxt); -int userauth_kbdint(Authctxt *authctxt); +static void userauth_banner(void); +static int userauth_none(Authctxt *); +static int userauth_passwd(Authctxt *); +static int userauth_pubkey(Authctxt *); +static int userauth_hostbased(Authctxt *); +static int userauth_kbdint(Authctxt *); Authmethod authmethods[] = { {"none", @@ -121,7 +119,7 @@ x_authctxt = authctxt; /*XXX*/ /* challenge-reponse is implemented via keyboard interactive */ - if (options.challenge_reponse_authentication) + if (options.challenge_response_authentication) options.kbd_interactive_authentication = 1; dispatch_init(&protocol_error); @@ -130,7 +128,7 @@ do_authenticated(authctxt); } -void +static void protocol_error(int type, int plen, void *ctxt) { log("auth: protocol error: type %d plen %d", type, plen); @@ -140,7 +138,7 @@ packet_write_wait(); } -void +static void input_service_request(int type, int plen, void *ctxt) { Authctxt *authctxt = ctxt; @@ -173,7 +171,7 @@ xfree(service); } -void +static void input_userauth_request(int type, int plen, void *ctxt) { Authctxt *authctxt = ctxt; @@ -207,14 +205,12 @@ setproctitle("%s", pw ? user : "unknown"); authctxt->user = xstrdup(user); authctxt->service = xstrdup(service); - authctxt->style = style ? xstrdup(style) : NULL; /* currently unused */ - } else if (authctxt->valid) { - if (strcmp(user, authctxt->user) != 0 || - strcmp(service, authctxt->service) != 0) { - log("input_userauth_request: mismatch: (%s,%s)!=(%s,%s)", - user, service, authctxt->user, authctxt->service); - authctxt->valid = 0; - } + authctxt->style = style ? xstrdup(style) : NULL; + } else if (strcmp(user, authctxt->user) != 0 || + strcmp(service, authctxt->service) != 0) { + packet_disconnect("Change of username or service not allowed: " + "(%s,%s) -> (%s,%s)", + authctxt->user, authctxt->service, user, service); } /* reset state */ dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error); @@ -242,6 +238,8 @@ void userauth_finish(Authctxt *authctxt, int authenticated, char *method) { + char *methods; + if (!authctxt->valid && authenticated) fatal("INTERNAL ERROR: authenticated invalid user %s", authctxt->user); @@ -254,11 +252,32 @@ /* Log before sending the reply */ auth_log(authctxt, authenticated, method, " ssh2"); - if (!authctxt->postponed) - userauth_reply(authctxt, authenticated); + if (authctxt->postponed) + return; + + /* XXX todo: check if multiple auth methods are needed */ + if (authenticated == 1) { + /* 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 */ + authctxt->success = 1; + } else { + if (authctxt->failures++ > AUTH_FAIL_MAX) + packet_disconnect(AUTH_FAIL_MSG, authctxt->user); + methods = authmethods_get(); + packet_start(SSH2_MSG_USERAUTH_FAILURE); + packet_put_cstring(methods); + packet_put_char(0); /* XXX partial success, unused */ + packet_send(); + packet_write_wait(); + xfree(methods); + } } -void +static void userauth_banner(void) { struct stat st; @@ -289,34 +308,7 @@ return; } -void -userauth_reply(Authctxt *authctxt, int authenticated) -{ - char *methods; - - /* XXX todo: check if multiple auth methods are needed */ - if (authenticated == 1) { - /* 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 */ - authctxt->success = 1; - } else { - if (authctxt->failures++ > AUTH_FAIL_MAX) - packet_disconnect(AUTH_FAIL_MSG, authctxt->user); - methods = authmethods_get(); - packet_start(SSH2_MSG_USERAUTH_FAILURE); - packet_put_cstring(methods); - packet_put_char(0); /* XXX partial success, unused */ - packet_send(); - packet_write_wait(); - xfree(methods); - } -} - -int +static int userauth_none(Authctxt *authctxt) { /* disable method "none", only allowed one time */ @@ -328,7 +320,7 @@ return authctxt->valid ? auth_password(authctxt, "") : 0; } -int +static int userauth_passwd(Authctxt *authctxt) { char *password; @@ -348,28 +340,27 @@ return authenticated; } -int +static int userauth_kbdint(Authctxt *authctxt) { int authenticated = 0; - char *lang = NULL; - char *devs = NULL; - + char *lang, *devs; + lang = packet_get_string(NULL); devs = packet_get_string(NULL); packet_done(); - debug("keyboard-interactive language %s devs %s", lang, devs); + debug("keyboard-interactive devs %s", devs); - if (options.challenge_reponse_authentication) + if (options.challenge_response_authentication) authenticated = auth2_challenge(authctxt, devs); - xfree(lang); xfree(devs); + xfree(lang); return authenticated; } -int +static int userauth_pubkey(Authctxt *authctxt) { Buffer b; @@ -471,7 +462,7 @@ return authenticated; } -int +static int userauth_hostbased(Authctxt *authctxt) { Buffer b; @@ -556,7 +547,7 @@ #define DELIM "," -char * +static char * authmethods_get(void) { Authmethod *method = NULL; @@ -588,7 +579,7 @@ return list; } -Authmethod * +static Authmethod * authmethod_lookup(const char *name) { Authmethod *method = NULL; @@ -603,10 +594,10 @@ } /* return 1 if user allows given key */ -int -user_key_allowed(struct passwd *pw, Key *key) +static int +user_key_allowed2(struct passwd *pw, Key *key, char *file) { - char line[8192], file[MAXPATHLEN]; + char line[8192]; int found_key = 0; FILE *f; u_long linenum = 0; @@ -619,9 +610,7 @@ /* Temporarily use the user's uid. */ temporarily_use_uid(pw); - /* The authorized keys. */ - snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir, - _PATH_SSH_USER_PERMITTED_KEYS2); + debug("trying public key file %s", file); /* Fail quietly if file does not exist */ if (stat(file, &st) < 0) { @@ -636,46 +625,14 @@ restore_uid(); 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, - "%s authentication refused for %.100s: " - "bad ownership or modes for '%s'.", - key_type(key), pw->pw_name, file); - fail = 1; - } else { - /* Check path to _PATH_SSH_USER_PERMITTED_KEYS */ - int i; - static const char *check[] = { - "", _PATH_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, - "%s authentication refused for %.100s: " - "bad ownership or modes for '%s'.", - key_type(key), pw->pw_name, line); - fail = 1; - break; - } - } - } - if (fail) { - fclose(f); - log("%s", buf); - restore_uid(); - return 0; - } + if (options.strict_modes && + secure_filename(f, file, pw, line, sizeof(line)) != 0) { + fclose(f); + log("Authentication refused: %s", line); + restore_uid(); + return 0; } + found_key = 0; found = key_new(key->type); @@ -688,7 +645,7 @@ if (!*cp || *cp == '\n' || *cp == '#') continue; - if (key_read(found, &cp) == -1) { + if (key_read(found, &cp) != 1) { /* no key? check if there are options for this key */ int quoted = 0; debug2("user_key_allowed: check options: '%s'", cp); @@ -702,7 +659,7 @@ /* Skip remaining whitespace. */ for (; *cp == ' ' || *cp == '\t'; cp++) ; - if (key_read(found, &cp) == -1) { + if (key_read(found, &cp) != 1) { debug2("user_key_allowed: advance: '%s'", cp); /* still no key? advance to next line*/ continue; @@ -711,7 +668,7 @@ if (key_equal(found, key) && auth_parse_options(pw, options, file, linenum) == 1) { found_key = 1; - debug("matching key found: file %s, line %ld", + debug("matching key found: file %s, line %lu", file, linenum); break; } @@ -724,15 +681,32 @@ return found_key; } +/* check whether given key is in .ssh/authorized_keys* */ +static int +user_key_allowed(struct passwd *pw, Key *key) +{ + int success; + char *file; + + file = authorized_keys_file(pw); + success = user_key_allowed2(pw, key, file); + xfree(file); + if (success) + return success; + + /* try suffix "2" for backward compat, too */ + file = authorized_keys_file2(pw); + success = user_key_allowed2(pw, key, file); + xfree(file); + return success; +} + /* return 1 if given hostkey is allowed */ -int +static int hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost, Key *key) { - Key *found; const char *resolvedname, *ipaddr, *lookup; - struct stat st; - char *user_hostfile; int host_status, len; resolvedname = get_canonical_hostname(options.reverse_mapping_check); @@ -760,32 +734,17 @@ } debug2("userauth_hostbased: access allowed by auth_rhosts2"); - /* XXX this is copied from auth-rh-rsa.c and should be shared */ - found = key_new(key->type); - host_status = check_host_in_hostfile(_PATH_SSH_SYSTEM_HOSTFILE2, lookup, - key, found, NULL); + host_status = check_key_in_hostfiles(pw, key, lookup, + _PATH_SSH_SYSTEM_HOSTFILE, + options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); - if (host_status != HOST_OK && !options.ignore_user_known_hosts) { - user_hostfile = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE2, - pw->pw_uid); - if (options.strict_modes && - (stat(user_hostfile, &st) == 0) && - ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || - (st.st_mode & 022) != 0)) { - log("Hostbased authentication refused for %.100s: " - "bad owner or modes for %.200s", - pw->pw_name, user_hostfile); - } else { - temporarily_use_uid(pw); - host_status = check_host_in_hostfile(user_hostfile, - lookup, key, found, NULL); - restore_uid(); - } - xfree(user_hostfile); - } - key_free(found); + /* backward compat if no key has been found. */ + if (host_status == HOST_NEW) + host_status = check_key_in_hostfiles(pw, key, lookup, + _PATH_SSH_SYSTEM_HOSTFILE2, + options.ignore_user_known_hosts ? NULL : + _PATH_SSH_USER_HOSTFILE2); - debug2("userauth_hostbased: key %s for %s", host_status == HOST_OK ? - "ok" : "not found", lookup); return (host_status == HOST_OK); } +