*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.20 2000/10/14 12:16:56 markus Exp $");
+RCSID("$OpenBSD: auth2.c,v 1.82 2002/01/13 17:57:37 markus Exp $");
-#ifdef HAVE_OSF_SIA
-# include <sia.h>
-# include <siad.h>
-#endif
-
-#include <openssl/dsa.h>
-#include <openssl/rsa.h>
#include <openssl/evp.h>
+#include "ssh2.h"
#include "xmalloc.h"
#include "rsa.h"
-#include "ssh.h"
-#include "pty.h"
+#include "sshpty.h"
#include "packet.h"
#include "buffer.h"
+#include "log.h"
#include "servconf.h"
#include "compat.h"
#include "channels.h"
#include "bufaux.h"
-#include "ssh2.h"
#include "auth.h"
#include "session.h"
#include "dispatch.h"
-#include "auth.h"
#include "key.h"
+#include "cipher.h"
#include "kex.h"
-
-#include "dsa.h"
+#include "pathnames.h"
#include "uidswap.h"
#include "auth-options.h"
+#include "misc.h"
+#include "hostfile.h"
+#include "canohost.h"
+#include "match.h"
/* import */
extern ServerOptions options;
-extern unsigned char *session_id2;
+extern u_char *session_id2;
extern int session_id2_len;
-#ifdef WITH_AIXAUTHENTICATE
-extern char *aixloginmsg;
-#endif
-#ifdef HAVE_OSF_SIA
-extern int saved_argc;
-extern char **saved_argv;
-#endif
-
static Authctxt *x_authctxt = NULL;
static int one = 1;
/* 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, u_int32_t, void *);
+static void input_userauth_request(int, u_int32_t, void *);
/* helper */
-Authmethod *authmethod_lookup(const char *name);
-struct passwd *pwcopy(struct passwd *pw);
-int user_dsa_key_allowed(struct passwd *pw, Key *key);
-char *authmethods_get(void);
+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 */
-int userauth_none(Authctxt *authctxt);
-int userauth_passwd(Authctxt *authctxt);
-int userauth_pubkey(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",
&one},
{"publickey",
userauth_pubkey,
- &options.dsa_authentication},
- {"keyboard-interactive",
- userauth_kbdint,
- &options.kbd_interactive_authentication},
+ &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}
};
*/
void
-do_authentication2()
+do_authentication2(void)
{
- Authctxt *authctxt = xmalloc(sizeof(*authctxt));
- memset(authctxt, 'a', sizeof(*authctxt));
- authctxt->valid = 0;
- authctxt->attempt = 0;
- authctxt->success = 0;
+ Authctxt *authctxt = authctxt_new();
+
x_authctxt = authctxt; /*XXX*/
-#ifdef KRB4
- /* turn off kerberos, not supported by SSH2 */
- options.kerberos_authentication = 0;
-#endif
- dispatch_init(&protocol_error);
+ /* 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;
+
+ dispatch_init(&dispatch_protocol_error);
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
- do_authenticated2();
+ do_authenticated(authctxt);
}
-void
-protocol_error(int type, int plen, void *ctxt)
-{
- 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, void *ctxt)
+static void
+input_service_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
- unsigned int len;
+ u_int len;
int accept = 0;
char *service = packet_get_string(&len);
- packet_done();
+ packet_check_eom();
if (authctxt == NULL)
fatal("input_service_request: no authctxt");
xfree(service);
}
-void
-input_userauth_request(int type, int plen, void *ctxt)
+static void
+input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
Authmethod *m = NULL;
- char *user, *service, *method;
+ char *user, *service, *method, *style = NULL;
int authenticated = 0;
if (authctxt == NULL)
fatal("input_userauth_request: no authctxt");
- if (authctxt->attempt++ >= AUTH_FAIL_MAX) {
-#ifdef WITH_AIXAUTHENTICATE
- loginfailed(authctxt->pw->pw_name, get_canonical_hostname(), "ssh");
-#endif /* WITH_AIXAUTHENTICATE */
- packet_disconnect("too many failed userauth_requests");
- }
user = packet_get_string(NULL);
service = packet_get_string(NULL);
method = packet_get_string(NULL);
debug("userauth-request for user %s service %s method %s", user, service, method);
- debug("attempt #%d", authctxt->attempt);
+ debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
- if (authctxt->attempt == 1) {
+ if ((style = strchr(user, ':')) != NULL)
+ *style++ = 0;
+
+ if (authctxt->attempt++ == 0) {
/* setup auth context */
struct passwd *pw = NULL;
- setproctitle("%s", user);
pw = getpwnam(user);
if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) {
authctxt->pw = pwcopy(pw);
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
#ifdef USE_PAM
- start_pam(pw);
+ start_pam(pw->pw_name);
#endif
} else {
log("input_userauth_request: illegal user %s", user);
+#ifdef USE_PAM
+ start_pam("NOUSER");
+#endif
}
+ setproctitle("%s", pw ? user : "unknown");
authctxt->user = xstrdup(user);
authctxt->service = xstrdup(service);
- } else if (authctxt->valid) {
- if (strcmp(user, authctxt->user) != 0 ||
- strcmp(service, authctxt->service) != 0) {
- log("input_userauth_request: missmatch: (%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 */
+ auth2_challenge_stop(authctxt);
+ authctxt->postponed = 0;
+ /* try to authenticate user */
m = authmethod_lookup(method);
if (m != NULL) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
- } else {
- debug2("input_userauth_request: unsupported method %s", method);
- }
- if (!authctxt->valid && authenticated == 1) {
- log("input_userauth_request: INTERNAL ERROR: authenticated invalid user %s service %s", user, method);
- authenticated = 0;
- }
-
- /* Special handling for root */
- if (authenticated == 1 &&
- authctxt->valid && authctxt->pw->pw_uid == 0 && !options.permit_root_login) {
- authenticated = 0;
- log("ROOT LOGIN REFUSED FROM %.200s", get_canonical_hostname());
}
-
-#ifdef USE_PAM
- if (authenticated && !do_pam_account(authctxt->pw->pw_name, NULL))
- authenticated = 0;
-#endif /* USE_PAM */
-
- /* Log before sending the reply */
- userauth_log(authctxt, authenticated, method);
- userauth_reply(authctxt, authenticated);
+ userauth_finish(authctxt, authenticated, method);
xfree(service);
xfree(user);
xfree(method);
}
-
void
-userauth_log(Authctxt *authctxt, int authenticated, char *method)
+userauth_finish(Authctxt *authctxt, int authenticated, char *method)
{
- void (*authlog) (const char *fmt,...) = verbose;
- char *user = NULL, *authmsg = NULL;
+ char *methods;
- /* Raise logging level */
- if (authenticated == 1 ||
- !authctxt->valid ||
- authctxt->attempt >= AUTH_FAIL_LOG ||
- strcmp(method, "password") == 0)
- authlog = log;
+ if (!authctxt->valid && authenticated)
+ fatal("INTERNAL ERROR: authenticated invalid user %s",
+ authctxt->user);
- if (authenticated == 1) {
- authmsg = "Accepted";
- } else if (authenticated == 0) {
- authmsg = "Failed";
- } else {
- authmsg = "Postponed";
- }
+ /* Special handling for root */
+ if (authenticated && authctxt->pw->pw_uid == 0 &&
+ !auth_root_allowed(method))
+ authenticated = 0;
- if (authctxt->valid) {
- user = authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user;
- } else {
- user = "NOUSER";
- }
+#ifdef USE_PAM
+ if (authenticated && authctxt->user && !do_pam_account(authctxt->user,
+ NULL))
+ authenticated = 0;
+#endif /* USE_PAM */
- authlog("%s %s for %.200s from %.200s port %d ssh2",
- authmsg,
- method,
- user,
- get_remote_ipaddr(),
- get_remote_port());
-}
+ /* Log before sending the reply */
+ auth_log(authctxt, authenticated, method, " ssh2");
+
+ if (authctxt->postponed)
+ return;
-void
-userauth_reply(Authctxt *authctxt, int authenticated)
-{
/* XXX todo: check if multiple auth methods are needed */
if (authenticated == 1) {
-#ifdef WITH_AIXAUTHENTICATE
- /* We don't have a pty yet, so just label the line as "ssh" */
- if (loginsuccess(authctxt->pw->pw_name, get_canonical_hostname(),
- "ssh", &aixloginmsg) < 0)
- aixloginmsg = NULL;
-#endif /* WITH_AIXAUTHENTICATE */
/* 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 (authenticated == 0) {
- char *methods = authmethods_get();
+ } else {
+ if (authctxt->failures++ > AUTH_FAIL_MAX) {
+#ifdef WITH_AIXAUTHENTICATE
+ loginfailed(authctxt->user,
+ get_canonical_hostname(options.reverse_mapping_check),
+ "ssh");
+#endif /* WITH_AIXAUTHENTICATE */
+ 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);
- } else {
- /* do nothing, we did already send a reply */
}
}
-int
+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();
+ packet_check_eom();
+ userauth_banner();
if (authctxt->valid == 0)
return(0);
-
+
#ifdef HAVE_CYGWIN
- if (check_nt_auth(1, authctxt->pw->pw_uid) == 0)
+ if (check_nt_auth(1, authctxt->pw) == 0)
return(0);
#endif
#ifdef USE_PAM
return auth_pam_password(authctxt->pw, "");
#elif defined(HAVE_OSF_SIA)
- return (sia_validate_user(NULL, saved_argc, saved_argv,
- get_canonical_hostname(), authctxt->pw->pw_name, NULL,
- 0, NULL, "") == SIASUCCESS);
+ return 0;
#else /* !HAVE_OSF_SIA && !USE_PAM */
- return auth_password(authctxt->pw, "");
+ return auth_password(authctxt, "");
#endif /* USE_PAM */
}
-int
+static int
userauth_passwd(Authctxt *authctxt)
{
char *password;
int authenticated = 0;
int change;
- unsigned int len;
+ u_int len;
change = packet_get_char();
if (change)
log("password change not supported");
password = packet_get_string(&len);
- packet_done();
+ packet_check_eom();
if (authctxt->valid &&
#ifdef HAVE_CYGWIN
- check_nt_auth(1, authctxt->pw->pw_uid) &&
+ check_nt_auth(1, authctxt->pw) &&
#endif
#ifdef USE_PAM
auth_pam_password(authctxt->pw, password) == 1)
#elif defined(HAVE_OSF_SIA)
- sia_validate_user(NULL, saved_argc, saved_argv,
- get_canonical_hostname(), authctxt->pw->pw_name, NULL, 0,
- NULL, password) == SIASUCCESS)
+ auth_sia_password(authctxt->user, password) == 1)
#else /* !USE_PAM && !HAVE_OSF_SIA */
- auth_password(authctxt->pw, password) == 1)
+ auth_password(authctxt, password) == 1)
#endif /* USE_PAM */
authenticated = 1;
memset(password, 0, len);
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();
+ packet_check_eom();
+
+ debug("keyboard-interactive devs %s", devs);
- debug("keyboard-interactive language %s devs %s", lang, devs);
-#ifdef SKEY
- /* XXX hardcoded, we should look at devs */
- if (options.skey_authentication != 0)
- authenticated = auth2_skey(authctxt);
+ 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(lang);
xfree(devs);
+ xfree(lang);
#ifdef HAVE_CYGWIN
- if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
+ if (check_nt_auth(0, authctxt->pw) == 0)
return(0);
#endif
return authenticated;
}
-int
+static int
userauth_pubkey(Authctxt *authctxt)
{
Buffer b;
Key *key;
char *pkalg, *pkblob, *sig;
- unsigned int alen, blen, slen;
- int have_sig;
+ u_int alen, blen, slen;
+ int have_sig, pktype;
int authenticated = 0;
if (!authctxt->valid) {
return 0;
}
have_sig = packet_get_char();
- pkalg = packet_get_string(&alen);
- if (strcmp(pkalg, KEX_DSS) != 0) {
- log("bad pkalg %s", pkalg); /*XXX*/
+ 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;
}
- pkblob = packet_get_string(&blen);
- key = dsa_key_from_blob(pkblob, blen);
+ key = key_from_blob(pkblob, blen);
if (key != NULL) {
if (have_sig) {
sig = packet_get_string(&slen);
- packet_done();
+ packet_check_eom();
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
buffer_put_cstring(&b, authctxt->user);
buffer_put_cstring(&b,
- datafellows & SSH_BUG_PUBKEYAUTH ?
+ datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
- buffer_put_cstring(&b, "publickey");
- buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, KEX_DSS);
+ 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_DSS
+#ifdef DEBUG_PK
buffer_dump(&b);
#endif
/* test for correct signature */
- if (user_dsa_key_allowed(authctxt->pw, key) &&
- dsa_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
+ 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();
+ packet_check_eom();
/* XXX fake reply and always send PK_OK ? */
/*
* if a user is not allowed to login. is this an
* issue? -markus
*/
- if (user_dsa_key_allowed(authctxt->pw, key)) {
+ 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();
- authenticated = -1;
+ 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)
+ if (check_nt_auth(0, authctxt->pw) == 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*
#define DELIM ","
-char *
+static char *
authmethods_get(void)
{
Authmethod *method = NULL;
- unsigned int size = 0;
+ Buffer b;
char *list;
+ buffer_init(&b);
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)
- continue;
- if (method->enabled != NULL && *(method->enabled) != 0) {
- if (list[0] != '\0')
- strlcat(list, DELIM, size);
- strlcat(list, method->name, size);
+ if (buffer_len(&b) > 0)
+ buffer_append(&b, ",", 1);
+ buffer_append(&b, method->name, strlen(method->name));
}
}
+ buffer_append(&b, "\0", 1);
+ list = xstrdup(buffer_ptr(&b));
+ buffer_free(&b);
return list;
}
-Authmethod *
+static Authmethod *
authmethod_lookup(const char *name)
{
Authmethod *method = NULL;
}
/* return 1 if user allows given key */
-int
-user_dsa_key_allowed(struct passwd *pw, Key *key)
+static int
+user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
- char line[8192], file[1024];
+ char line[8192];
int found_key = 0;
- unsigned int bits = -1;
FILE *f;
- unsigned long linenum = 0;
+ 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->pw_uid);
+ temporarily_use_uid(pw);
- /* The authorized keys. */
- snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir,
- SSH_USER_PERMITTED_KEYS2);
+ debug("trying public key file %s", file);
/* Fail quietly if file does not exist */
if (stat(file, &st) < 0) {
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 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,
- "%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);
if (!*cp || *cp == '\n' || *cp == '#')
continue;
- bits = key_read(found, &cp);
- if (bits == 0) {
+ 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] == '"')
/* Skip remaining whitespace. */
for (; *cp == ' ' || *cp == '\t'; cp++)
;
- bits = key_read(found, &cp);
- if (bits == 0) {
+ 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, linenum) == 1) {
+ 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);
+ 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;
}
-struct passwd *
-pwcopy(struct passwd *pw)
+/* check whether given key is in .ssh/authorized_keys* */
+static int
+user_key_allowed(struct passwd *pw, Key *key)
{
- struct passwd *copy = xmalloc(sizeof(*copy));
- 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;
-#ifdef HAVE_PW_CLASS_IN_PASSWD
- copy->pw_class = xstrdup(pw->pw_class);
-#endif
- copy->pw_dir = xstrdup(pw->pw_dir);
- copy->pw_shell = xstrdup(pw->pw_shell);
- return copy;
+ 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);
+}
+
andersk / openssh.git / blobdiff