+/* $OpenBSD: auth2.c,v 1.121 2009/06/22 05:39:28 dtucker Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.78 2001/12/20 22:50:24 djm Exp $");
-#include <openssl/evp.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
-#include "ssh2.h"
+#include <fcntl.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "atomicio.h"
#include "xmalloc.h"
-#include "rsa.h"
-#include "sshpty.h"
+#include "ssh2.h"
#include "packet.h"
-#include "buffer.h"
#include "log.h"
+#include "buffer.h"
#include "servconf.h"
#include "compat.h"
-#include "channels.h"
-#include "bufaux.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
-#include "session.h"
#include "dispatch.h"
-#include "key.h"
-#include "cipher.h"
-#include "kex.h"
#include "pathnames.h"
-#include "uidswap.h"
-#include "auth-options.h"
-#include "misc.h"
-#include "hostfile.h"
-#include "canohost.h"
-#include "match.h"
+#include "buffer.h"
+
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "monitor_wrap.h"
/* import */
extern ServerOptions options;
extern u_char *session_id2;
-extern int session_id2_len;
-
-static Authctxt *x_authctxt = NULL;
-static int one = 1;
+extern u_int session_id2_len;
+extern Buffer loginmsg;
+
+/* methods */
+
+extern Authmethod method_none;
+extern Authmethod method_pubkey;
+extern Authmethod method_passwd;
+extern Authmethod method_kbdint;
+extern Authmethod method_hostbased;
+#ifdef GSSAPI
+extern Authmethod method_gssapi;
+#endif
+#ifdef JPAKE
+extern Authmethod method_jpake;
+#endif
-typedef struct Authmethod Authmethod;
-struct Authmethod {
- char *name;
- int (*userauth)(Authctxt *authctxt);
- int *enabled;
+Authmethod *authmethods[] = {
+ &method_none,
+ &method_pubkey,
+#ifdef GSSAPI
+ &method_gssapi,
+#endif
+#ifdef JPAKE
+ &method_jpake,
+#endif
+ &method_passwd,
+ &method_kbdint,
+ &method_hostbased,
+ NULL
};
/* protocol */
-static void input_service_request(int, int, u_int32_t, void *);
-static void input_userauth_request(int, int, u_int32_t, void *);
-static void protocol_error(int, int, u_int32_t, void *);
+static void input_service_request(int, u_int32_t, void *);
+static void input_userauth_request(int, u_int32_t, void *);
/* helper */
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 */
-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",
- userauth_none,
- &one},
- {"publickey",
- userauth_pubkey,
- &options.pubkey_authentication},
- {"password",
- userauth_passwd,
- &options.password_authentication},
- {"keyboard-interactive",
- userauth_kbdint,
- &options.kbd_interactive_authentication},
- {"hostbased",
- userauth_hostbased,
- &options.hostbased_authentication},
- {NULL, NULL, NULL}
-};
-/*
- * loop until authctxt->success == TRUE
- */
+char *
+auth2_read_banner(void)
+{
+ struct stat st;
+ char *banner = NULL;
+ size_t len, n;
+ int fd;
+
+ if ((fd = open(options.banner, O_RDONLY)) == -1)
+ return (NULL);
+ if (fstat(fd, &st) == -1) {
+ close(fd);
+ return (NULL);
+ }
+ if (st.st_size > 1*1024*1024) {
+ close(fd);
+ return (NULL);
+ }
+
+ len = (size_t)st.st_size; /* truncate */
+ banner = xmalloc(len + 1);
+ n = atomicio(read, fd, banner, len);
+ close(fd);
+
+ if (n != len) {
+ xfree(banner);
+ return (NULL);
+ }
+ banner[n] = '\0';
+
+ return (banner);
+}
void
-do_authentication2(void)
+userauth_send_banner(const char *msg)
{
- Authctxt *authctxt = authctxt_new();
+ if (datafellows & SSH_BUG_BANNER)
+ return;
- x_authctxt = authctxt; /*XXX*/
+ packet_start(SSH2_MSG_USERAUTH_BANNER);
+ packet_put_cstring(msg);
+ packet_put_cstring(""); /* language, unused */
+ packet_send();
+ debug("%s: sent", __func__);
+}
- /* challenge-response is implemented via keyboard interactive */
- if (options.challenge_response_authentication)
- options.kbd_interactive_authentication = 1;
- if (options.pam_authentication_via_kbd_int)
- options.kbd_interactive_authentication = 1;
+static void
+userauth_banner(void)
+{
+ char *banner = NULL;
- dispatch_init(&protocol_error);
- dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
- dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
- do_authenticated(authctxt);
+ if (options.banner == NULL ||
+ strcasecmp(options.banner, "none") == 0 ||
+ (datafellows & SSH_BUG_BANNER) != 0)
+ return;
+
+ if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
+ goto done;
+ userauth_send_banner(banner);
+
+done:
+ if (banner)
+ xfree(banner);
}
-static void
-protocol_error(int type, int plen, u_int32_t seq, void *ctxt)
+/*
+ * loop until authctxt->success == TRUE
+ */
+void
+do_authentication2(Authctxt *authctxt)
{
- log("auth: protocol error: type %d plen %d", type, plen);
- packet_start(SSH2_MSG_UNIMPLEMENTED);
- packet_put_int(seq);
- packet_send();
- packet_write_wait();
+ dispatch_init(&dispatch_protocol_error);
+ dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
+ dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
}
+/*ARGSUSED*/
static void
-input_service_request(int type, int plen, u_int32_t seq, void *ctxt)
+input_service_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
u_int len;
- int accept = 0;
+ int acceptit = 0;
char *service = packet_get_string(&len);
- packet_done();
+ packet_check_eom();
if (authctxt == NULL)
fatal("input_service_request: no authctxt");
if (strcmp(service, "ssh-userauth") == 0) {
if (!authctxt->success) {
- accept = 1;
+ acceptit = 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) {
+ if (acceptit) {
packet_start(SSH2_MSG_SERVICE_ACCEPT);
packet_put_cstring(service);
packet_send();
xfree(service);
}
+/*ARGSUSED*/
static void
-input_userauth_request(int type, int plen, u_int32_t seq, void *ctxt)
+input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
Authmethod *m = NULL;
if (authctxt->attempt++ == 0) {
/* setup auth context */
- struct passwd *pw = NULL;
- pw = getpwnam(user);
- if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) {
- authctxt->pw = pwcopy(pw);
+ authctxt->pw = PRIVSEP(getpwnamallow(user));
+ authctxt->user = xstrdup(user);
+ if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
-#ifdef USE_PAM
- start_pam(pw->pw_name);
-#endif
} else {
- log("input_userauth_request: illegal user %s", user);
-#ifdef USE_PAM
- start_pam("NOUSER");
+ logit("input_userauth_request: invalid user %s", user);
+ authctxt->pw = fakepw();
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
}
- setproctitle("%s", pw ? user : "unknown");
- authctxt->user = xstrdup(user);
+#ifdef USE_PAM
+ if (options.use_pam)
+ PRIVSEP(start_pam(authctxt));
+#endif
+ setproctitle("%s%s", authctxt->valid ? user : "unknown",
+ use_privsep ? " [net]" : "");
authctxt->service = xstrdup(service);
authctxt->style = style ? xstrdup(style) : NULL;
+ if (use_privsep)
+ mm_inform_authserv(service, style);
+ userauth_banner();
} else if (strcmp(user, authctxt->user) != 0 ||
strcmp(service, authctxt->service) != 0) {
packet_disconnect("Change of username or service not allowed: "
}
/* reset state */
auth2_challenge_stop(authctxt);
+#ifdef JPAKE
+ auth2_jpake_stop(authctxt);
+#endif
+
+#ifdef GSSAPI
+ /* XXX move to auth2_gssapi_stop() */
+ dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+ dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
+#endif
+
authctxt->postponed = 0;
/* try to authenticate user */
m = authmethod_lookup(method);
- if (m != NULL) {
+ if (m != NULL && authctxt->failures < options.max_authtries) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
}
/* Special handling for root */
if (authenticated && authctxt->pw->pw_uid == 0 &&
- !auth_root_allowed(method))
+ !auth_root_allowed(method)) {
authenticated = 0;
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
+#endif
+ }
#ifdef USE_PAM
- if (authenticated && authctxt->user && !do_pam_account(authctxt->user,
- NULL))
+ if (options.use_pam && authenticated) {
+ if (!PRIVSEP(do_pam_account())) {
+ /* if PAM returned a message, send it to the user */
+ if (buffer_len(&loginmsg) > 0) {
+ buffer_append(&loginmsg, "\0", 1);
+ userauth_send_banner(buffer_ptr(&loginmsg));
+ packet_write_wait();
+ }
+ fatal("Access denied for user %s by PAM account "
+ "configuration", authctxt->user);
+ }
+ }
+#endif
+
+#ifdef _UNICOS
+ if (authenticated && cray_access_denied(authctxt->user)) {
authenticated = 0;
-#endif /* USE_PAM */
+ fatal("Access denied for user %s.",authctxt->user);
+ }
+#endif /* _UNICOS */
/* Log before sending the reply */
auth_log(authctxt, authenticated, method, " ssh2");
/* XXX todo: check if multiple auth methods are needed */
if (authenticated == 1) {
/* turn off userauth */
- dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error);
+ dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
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) {
-#ifdef WITH_AIXAUTHENTICATE
- loginfailed(authctxt->user,
- get_canonical_hostname(options.reverse_mapping_check),
- "ssh");
-#endif /* WITH_AIXAUTHENTICATE */
+
+ /* Allow initial try of "none" auth without failure penalty */
+ if (authctxt->attempt > 1 || strcmp(method, "none") != 0)
+ authctxt->failures++;
+ 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);
}
methods = authmethods_get();
}
}
-static void
-userauth_banner(void)
-{
- struct stat st;
- char *banner = NULL;
- off_t len, n;
- int fd;
-
- if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
- return;
- if ((fd = open(options.banner, O_RDONLY)) < 0)
- return;
- if (fstat(fd, &st) < 0)
- goto done;
- len = st.st_size;
- banner = xmalloc(len + 1);
- if ((n = read(fd, banner, len)) < 0)
- goto done;
- banner[n] = '\0';
- packet_start(SSH2_MSG_USERAUTH_BANNER);
- packet_put_cstring(banner);
- packet_put_cstring(""); /* language, unused */
- packet_send();
- debug("userauth_banner: sent");
-done:
- if (banner)
- xfree(banner);
- close(fd);
- return;
-}
-
-static int
-userauth_none(Authctxt *authctxt)
-{
- /* disable method "none", only allowed one time */
- Authmethod *m = authmethod_lookup("none");
- if (m != NULL)
- m->enabled = NULL;
- packet_done();
- userauth_banner();
-
- if (authctxt->valid == 0)
- return(0);
-
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(1, authctxt->pw->pw_uid) == 0)
- return(0);
-#endif
-#ifdef USE_PAM
- return auth_pam_password(authctxt->pw, "");
-#elif defined(HAVE_OSF_SIA)
- return 0;
-#else /* !HAVE_OSF_SIA && !USE_PAM */
- return auth_password(authctxt, "");
-#endif /* USE_PAM */
-}
-
-static int
-userauth_passwd(Authctxt *authctxt)
-{
- char *password;
- int authenticated = 0;
- int change;
- u_int len;
- change = packet_get_char();
- if (change)
- log("password change not supported");
- password = packet_get_string(&len);
- packet_done();
- if (authctxt->valid &&
-#ifdef HAVE_CYGWIN
- check_nt_auth(1, authctxt->pw->pw_uid) &&
-#endif
-#ifdef USE_PAM
- auth_pam_password(authctxt->pw, password) == 1)
-#elif defined(HAVE_OSF_SIA)
- auth_sia_password(authctxt->user, password) == 1)
-#else /* !USE_PAM && !HAVE_OSF_SIA */
- auth_password(authctxt, password) == 1)
-#endif /* USE_PAM */
- authenticated = 1;
- memset(password, 0, len);
- xfree(password);
- return authenticated;
-}
-
-static int
-userauth_kbdint(Authctxt *authctxt)
-{
- int authenticated = 0;
- char *lang, *devs;
-
- lang = packet_get_string(NULL);
- devs = packet_get_string(NULL);
- packet_done();
-
- debug("keyboard-interactive devs %s", devs);
-
- if (options.challenge_response_authentication)
- authenticated = auth2_challenge(authctxt, devs);
-
-#ifdef USE_PAM
- if (authenticated == 0 && options.pam_authentication_via_kbd_int)
- authenticated = auth2_pam(authctxt);
-#endif
- xfree(devs);
- xfree(lang);
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
- return(0);
-#endif
- return authenticated;
-}
-
-static int
-userauth_pubkey(Authctxt *authctxt)
-{
- Buffer b;
- Key *key;
- char *pkalg, *pkblob, *sig;
- u_int alen, blen, slen;
- int have_sig, pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_pubkey: disabled because of invalid user");
- return 0;
- }
- have_sig = packet_get_char();
- if (datafellows & SSH_BUG_PKAUTH) {
- debug2("userauth_pubkey: SSH_BUG_PKAUTH");
- /* no explicit pkalg given */
- pkblob = packet_get_string(&blen);
- buffer_init(&b);
- buffer_append(&b, pkblob, blen);
- /* so we have to extract the pkalg from the pkblob */
- pkalg = buffer_get_string(&b, &alen);
- buffer_free(&b);
- } else {
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- }
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_pubkey: unsupported public key algorithm: %s", pkalg);
- xfree(pkalg);
- xfree(pkblob);
- return 0;
- }
- key = key_from_blob(pkblob, blen);
- if (key != NULL) {
- if (have_sig) {
- sig = packet_get_string(&slen);
- packet_done();
- buffer_init(&b);
- if (datafellows & SSH_OLD_SESSIONID) {
- buffer_append(&b, session_id2, session_id2_len);
- } else {
- buffer_put_string(&b, session_id2, session_id2_len);
- }
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b,
- datafellows & SSH_BUG_PKSERVICE ?
- "ssh-userauth" :
- authctxt->service);
- if (datafellows & SSH_BUG_PKAUTH) {
- buffer_put_char(&b, have_sig);
- } else {
- buffer_put_cstring(&b, "publickey");
- buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, pkalg);
- }
- buffer_put_string(&b, pkblob, blen);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for correct signature */
- if (user_key_allowed(authctxt->pw, key) &&
- key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
- authenticated = 1;
- buffer_clear(&b);
- xfree(sig);
- } else {
- debug("test whether pkalg/pkblob are acceptable");
- packet_done();
-
- /* XXX fake reply and always send PK_OK ? */
- /*
- * XXX this allows testing whether a user is allowed
- * to login: if you happen to have a valid pubkey this
- * message is sent. the message is NEVER sent at all
- * if a user is not allowed to login. is this an
- * issue? -markus
- */
- if (user_key_allowed(authctxt->pw, key)) {
- packet_start(SSH2_MSG_USERAUTH_PK_OK);
- packet_put_string(pkalg, alen);
- packet_put_string(pkblob, blen);
- packet_send();
- packet_write_wait();
- authctxt->postponed = 1;
- }
- }
- if (authenticated != 1)
- auth_clear_options();
- key_free(key);
- }
- debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
- xfree(pkalg);
- xfree(pkblob);
-#ifdef HAVE_CYGWIN
- if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
- return(0);
-#endif
- return authenticated;
-}
-
-static int
-userauth_hostbased(Authctxt *authctxt)
-{
- Buffer b;
- Key *key;
- char *pkalg, *pkblob, *sig, *cuser, *chost, *service;
- u_int alen, blen, slen;
- int pktype;
- int authenticated = 0;
-
- if (!authctxt->valid) {
- debug2("userauth_hostbased: disabled because of invalid user");
- return 0;
- }
- pkalg = packet_get_string(&alen);
- pkblob = packet_get_string(&blen);
- chost = packet_get_string(NULL);
- cuser = packet_get_string(NULL);
- sig = packet_get_string(&slen);
-
- debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d",
- cuser, chost, pkalg, slen);
-#ifdef DEBUG_PK
- debug("signature:");
- buffer_init(&b);
- buffer_append(&b, sig, slen);
- buffer_dump(&b);
- buffer_free(&b);
-#endif
- pktype = key_type_from_name(pkalg);
- if (pktype == KEY_UNSPEC) {
- /* this is perfectly legal */
- log("userauth_hostbased: unsupported "
- "public key algorithm: %s", pkalg);
- goto done;
- }
- key = key_from_blob(pkblob, blen);
- if (key == NULL) {
- debug("userauth_hostbased: cannot decode key: %s", pkalg);
- goto done;
- }
- service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
- authctxt->service;
- buffer_init(&b);
- buffer_put_string(&b, session_id2, session_id2_len);
- /* reconstruct packet */
- buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
- buffer_put_cstring(&b, authctxt->user);
- buffer_put_cstring(&b, service);
- buffer_put_cstring(&b, "hostbased");
- buffer_put_string(&b, pkalg, alen);
- buffer_put_string(&b, pkblob, blen);
- buffer_put_cstring(&b, chost);
- buffer_put_cstring(&b, cuser);
-#ifdef DEBUG_PK
- buffer_dump(&b);
-#endif
- /* test for allowed key and correct signature */
- if (hostbased_key_allowed(authctxt->pw, cuser, chost, key) &&
- key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
- authenticated = 1;
-
- buffer_clear(&b);
- key_free(key);
-
-done:
- debug2("userauth_hostbased: authenticated %d", authenticated);
- xfree(pkalg);
- xfree(pkblob);
- xfree(cuser);
- xfree(chost);
- xfree(sig);
- return authenticated;
-}
-
-/* get current user */
-
-struct passwd*
-auth_get_user(void)
-{
- return (x_authctxt != NULL && x_authctxt->valid) ? x_authctxt->pw : NULL;
-}
-
-#define DELIM ","
-
static char *
authmethods_get(void)
{
- Authmethod *method = NULL;
- u_int size = 0;
+ Buffer b;
char *list;
+ int i;
- for (method = authmethods; method->name != NULL; method++) {
- if (strcmp(method->name, "none") == 0)
- continue;
- if (method->enabled != NULL && *(method->enabled) != 0) {
- if (size != 0)
- size += strlen(DELIM);
- size += strlen(method->name);
- }
- }
- size++; /* trailing '\0' */
- list = xmalloc(size);
- list[0] = '\0';
-
- for (method = authmethods; method->name != NULL; method++) {
- if (strcmp(method->name, "none") == 0)
+ buffer_init(&b);
+ for (i = 0; authmethods[i] != NULL; i++) {
+ if (strcmp(authmethods[i]->name, "none") == 0)
continue;
- if (method->enabled != NULL && *(method->enabled) != 0) {
- if (list[0] != '\0')
- strlcat(list, DELIM, size);
- strlcat(list, method->name, size);
+ if (authmethods[i]->enabled != NULL &&
+ *(authmethods[i]->enabled) != 0) {
+ if (buffer_len(&b) > 0)
+ buffer_append(&b, ",", 1);
+ buffer_append(&b, authmethods[i]->name,
+ strlen(authmethods[i]->name));
}
}
+ buffer_append(&b, "\0", 1);
+ list = xstrdup(buffer_ptr(&b));
+ buffer_free(&b);
return list;
}
static Authmethod *
authmethod_lookup(const char *name)
{
- Authmethod *method = NULL;
+ int i;
+
if (name != NULL)
- for (method = authmethods; method->name != NULL; method++)
- if (method->enabled != NULL &&
- *(method->enabled) != 0 &&
- strcmp(name, method->name) == 0)
- return method;
- debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
+ for (i = 0; authmethods[i] != NULL; i++)
+ if (authmethods[i]->enabled != NULL &&
+ *(authmethods[i]->enabled) != 0 &&
+ strcmp(name, authmethods[i]->name) == 0)
+ return authmethods[i];
+ debug2("Unrecognized authentication method name: %s",
+ name ? name : "NULL");
return NULL;
}
-/* return 1 if user allows given key */
-static int
-user_key_allowed2(struct passwd *pw, Key *key, char *file)
-{
- char line[8192];
- int found_key = 0;
- FILE *f;
- u_long linenum = 0;
- struct stat st;
- Key *found;
- char *fp;
-
- if (pw == NULL)
- return 0;
-
- /* Temporarily use the user's uid. */
- temporarily_use_uid(pw);
-
- debug("trying public key file %s", file);
-
- /* 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();
- 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);
-
- while (fgets(line, sizeof(line), f)) {
- char *cp, *options = NULL;
- linenum++;
- /* Skip leading whitespace, empty and comment lines. */
- for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (!*cp || *cp == '\n' || *cp == '#')
- continue;
-
- 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);
- options = cp;
- for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
- if (*cp == '\\' && cp[1] == '"')
- cp++; /* Skip both */
- else if (*cp == '"')
- quoted = !quoted;
- }
- /* Skip remaining whitespace. */
- for (; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (key_read(found, &cp) != 1) {
- debug2("user_key_allowed: advance: '%s'", cp);
- /* still no key? advance to next line*/
- continue;
- }
- }
- if (key_equal(found, key) &&
- auth_parse_options(pw, options, file, linenum) == 1) {
- found_key = 1;
- debug("matching key found: file %s, line %lu",
- file, linenum);
- fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
- verbose("Found matching %s key: %s",
- key_type(found), fp);
- xfree(fp);
- break;
- }
- }
- restore_uid();
- fclose(f);
- key_free(found);
- if (!found_key)
- debug2("key not found");
- 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 */
-static int
-hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
- Key *key)
-{
- const char *resolvedname, *ipaddr, *lookup;
- HostStatus host_status;
- int len;
-
- resolvedname = get_canonical_hostname(options.reverse_mapping_check);
- ipaddr = get_remote_ipaddr();
-
- debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s",
- chost, resolvedname, ipaddr);
-
- if (options.hostbased_uses_name_from_packet_only) {
- if (auth_rhosts2(pw, cuser, chost, chost) == 0)
- return 0;
- lookup = chost;
- } else {
- if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') {
- debug2("stripping trailing dot from chost %s", chost);
- chost[len - 1] = '\0';
- }
- if (strcasecmp(resolvedname, chost) != 0)
- log("userauth_hostbased mismatch: "
- "client sends %s, but we resolve %s to %s",
- chost, ipaddr, resolvedname);
- if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0)
- return 0;
- lookup = resolvedname;
- }
- debug2("userauth_hostbased: access allowed by auth_rhosts2");
-
- host_status = check_key_in_hostfiles(pw, key, lookup,
- _PATH_SSH_SYSTEM_HOSTFILE,
- options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE);
-
- /* 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);
-
- return (host_status == HOST_OK);
-}
-