external/openssh: update to 6.8p1.
In preparation for some updates to external/openssh to make it work with
BoringSSL, this change updates the code to a recent version. The current
version (5.9p1) is coming up on four years old now.
* Confirmed that f5c67b478bef9992de9e9ec91ce10af4f6205e0d matches
OpenSSH 5.9p1 exactly (save for the removal of the scard
subdirectory).
* Downloaded openssh-6.8p1.tar.gz (SHA256:
3ff64ce73ee124480b5bf767b9830d7d3c03bbcb6abe716b78f0192c37ce160e)
and verified with PGP signature. (I've verified Damien's key in
person previously.)
* Applied changes between f5c67b478bef9992de9e9ec91ce10af4f6205e0d and
OpenSSH 5.9p1 to 6.8p1 and updated the build as best I can. The
ugliest change is probably the duplication of umac.c to umac128.c
because Android conditionally compiles that file twice. See the
comment in those files.
Change-Id: I63cb07a8118afb5a377f116087a0882914cea486
diff --git a/auth2.c b/auth2.c
index c06c95f..7177962 100644
--- a/auth2.c
+++ b/auth2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2.c,v 1.123 2011/03/10 02:52:57 djm Exp $ */
+/* $OpenBSD: auth2.c,v 1.135 2015/01/19 20:07:45 markus Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
@@ -41,6 +41,7 @@
#include "packet.h"
#include "log.h"
#include "buffer.h"
+#include "misc.h"
#include "servconf.h"
#include "compat.h"
#include "key.h"
@@ -71,9 +72,6 @@
#ifdef GSSAPI
extern Authmethod method_gssapi;
#endif
-#ifdef JPAKE
-extern Authmethod method_jpake;
-#endif
Authmethod *authmethods[] = {
&method_none,
@@ -81,9 +79,6 @@
#ifdef GSSAPI
&method_gssapi,
#endif
-#ifdef JPAKE
- &method_jpake,
-#endif
&method_passwd,
&method_kbdint,
&method_hostbased,
@@ -92,12 +87,18 @@
/* protocol */
-static void input_service_request(int, u_int32_t, void *);
-static void input_userauth_request(int, u_int32_t, void *);
+static int input_service_request(int, u_int32_t, void *);
+static int input_userauth_request(int, u_int32_t, void *);
/* helper */
-static Authmethod *authmethod_lookup(const char *);
-static char *authmethods_get(void);
+static Authmethod *authmethod_lookup(Authctxt *, const char *);
+static char *authmethods_get(Authctxt *authctxt);
+
+#define MATCH_NONE 0 /* method or submethod mismatch */
+#define MATCH_METHOD 1 /* method matches (no submethod specified) */
+#define MATCH_BOTH 2 /* method and submethod match */
+#define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */
+static int list_starts_with(const char *, const char *, const char *);
char *
auth2_read_banner(void)
@@ -113,7 +114,7 @@
close(fd);
return (NULL);
}
- if (st.st_size > 1*1024*1024) {
+ if (st.st_size <= 0 || st.st_size > 1*1024*1024) {
close(fd);
return (NULL);
}
@@ -124,7 +125,7 @@
close(fd);
if (n != len) {
- xfree(banner);
+ free(banner);
return (NULL);
}
banner[n] = '\0';
@@ -150,9 +151,7 @@
{
char *banner = NULL;
- if (options.banner == NULL ||
- strcasecmp(options.banner, "none") == 0 ||
- (datafellows & SSH_BUG_BANNER) != 0)
+ if (options.banner == NULL || (datafellows & SSH_BUG_BANNER) != 0)
return;
if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
@@ -160,8 +159,7 @@
userauth_send_banner(banner);
done:
- if (banner)
- xfree(banner);
+ free(banner);
}
/*
@@ -176,7 +174,7 @@
}
/*ARGSUSED*/
-static void
+static int
input_service_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
@@ -206,11 +204,12 @@
debug("bad service request %s", service);
packet_disconnect("bad service request %s", service);
}
- xfree(service);
+ free(service);
+ return 0;
}
/*ARGSUSED*/
-static void
+static int
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
@@ -255,6 +254,8 @@
if (use_privsep)
mm_inform_authserv(service, style);
userauth_banner();
+ if (auth2_setup_methods_lists(authctxt) != 0)
+ packet_disconnect("no authentication methods enabled");
} else if (strcmp(user, authctxt->user) != 0 ||
strcmp(service, authctxt->service) != 0) {
packet_disconnect("Change of username or service not allowed: "
@@ -263,9 +264,6 @@
}
/* reset state */
auth2_challenge_stop(authctxt);
-#ifdef JPAKE
- auth2_jpake_stop(authctxt);
-#endif
#ifdef GSSAPI
/* XXX move to auth2_gssapi_stop() */
@@ -277,26 +275,31 @@
authctxt->server_caused_failure = 0;
/* try to authenticate user */
- m = authmethod_lookup(method);
+ m = authmethod_lookup(authctxt, method);
if (m != NULL && authctxt->failures < options.max_authtries) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
}
- userauth_finish(authctxt, authenticated, method);
+ userauth_finish(authctxt, authenticated, method, NULL);
- xfree(service);
- xfree(user);
- xfree(method);
+ free(service);
+ free(user);
+ free(method);
+ return 0;
}
void
-userauth_finish(Authctxt *authctxt, int authenticated, char *method)
+userauth_finish(Authctxt *authctxt, int authenticated, const char *method,
+ const char *submethod)
{
char *methods;
+ int partial = 0;
if (!authctxt->valid && authenticated)
fatal("INTERNAL ERROR: authenticated invalid user %s",
authctxt->user);
+ if (authenticated && authctxt->postponed)
+ fatal("INTERNAL ERROR: authenticated and postponed");
/* Special handling for root */
if (authenticated && authctxt->pw->pw_uid == 0 &&
@@ -307,6 +310,19 @@
#endif
}
+ if (authenticated && options.num_auth_methods != 0) {
+ if (!auth2_update_methods_lists(authctxt, method, submethod)) {
+ authenticated = 0;
+ partial = 1;
+ }
+ }
+
+ /* Log before sending the reply */
+ auth_log(authctxt, authenticated, partial, method, submethod);
+
+ if (authctxt->postponed)
+ return;
+
#ifdef USE_PAM
if (options.use_pam && authenticated) {
if (!PRIVSEP(do_pam_account())) {
@@ -325,17 +341,10 @@
#ifdef _UNICOS
if (authenticated && cray_access_denied(authctxt->user)) {
authenticated = 0;
- fatal("Access denied for user %s.",authctxt->user);
+ fatal("Access denied for user %s.", authctxt->user);
}
#endif /* _UNICOS */
- /* Log before sending the reply */
- auth_log(authctxt, authenticated, method, " ssh2");
-
- 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, &dispatch_protocol_ignore);
@@ -347,43 +356,73 @@
} else {
/* Allow initial try of "none" auth without failure penalty */
- if (!authctxt->server_caused_failure &&
+ if (!partial && !authctxt->server_caused_failure &&
(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);
+ auth_maxtries_exceeded(authctxt);
}
- methods = authmethods_get();
+ methods = authmethods_get(authctxt);
+ debug3("%s: failure partial=%d next methods=\"%s\"", __func__,
+ partial, methods);
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring(methods);
- packet_put_char(0); /* XXX partial success, unused */
+ packet_put_char(partial);
packet_send();
packet_write_wait();
- xfree(methods);
+ free(methods);
}
}
+/*
+ * Checks whether method is allowed by at least one AuthenticationMethods
+ * methods list. Returns 1 if allowed, or no methods lists configured.
+ * 0 otherwise.
+ */
+int
+auth2_method_allowed(Authctxt *authctxt, const char *method,
+ const char *submethod)
+{
+ u_int i;
+
+ /*
+ * NB. authctxt->num_auth_methods might be zero as a result of
+ * auth2_setup_methods_lists(), so check the configuration.
+ */
+ if (options.num_auth_methods == 0)
+ return 1;
+ for (i = 0; i < authctxt->num_auth_methods; i++) {
+ if (list_starts_with(authctxt->auth_methods[i], method,
+ submethod) != MATCH_NONE)
+ return 1;
+ }
+ return 0;
+}
+
static char *
-authmethods_get(void)
+authmethods_get(Authctxt *authctxt)
{
Buffer b;
char *list;
- int i;
+ u_int i;
buffer_init(&b);
for (i = 0; authmethods[i] != NULL; i++) {
if (strcmp(authmethods[i]->name, "none") == 0)
continue;
- 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));
- }
+ if (authmethods[i]->enabled == NULL ||
+ *(authmethods[i]->enabled) == 0)
+ continue;
+ if (!auth2_method_allowed(authctxt, authmethods[i]->name,
+ NULL))
+ continue;
+ 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));
@@ -392,7 +431,7 @@
}
static Authmethod *
-authmethod_lookup(const char *name)
+authmethod_lookup(Authctxt *authctxt, const char *name)
{
int i;
@@ -400,10 +439,181 @@
for (i = 0; authmethods[i] != NULL; i++)
if (authmethods[i]->enabled != NULL &&
*(authmethods[i]->enabled) != 0 &&
- strcmp(name, authmethods[i]->name) == 0)
+ strcmp(name, authmethods[i]->name) == 0 &&
+ auth2_method_allowed(authctxt,
+ authmethods[i]->name, NULL))
return authmethods[i];
debug2("Unrecognized authentication method name: %s",
name ? name : "NULL");
return NULL;
}
+/*
+ * Check a comma-separated list of methods for validity. Is need_enable is
+ * non-zero, then also require that the methods are enabled.
+ * Returns 0 on success or -1 if the methods list is invalid.
+ */
+int
+auth2_methods_valid(const char *_methods, int need_enable)
+{
+ char *methods, *omethods, *method, *p;
+ u_int i, found;
+ int ret = -1;
+
+ if (*_methods == '\0') {
+ error("empty authentication method list");
+ return -1;
+ }
+ omethods = methods = xstrdup(_methods);
+ while ((method = strsep(&methods, ",")) != NULL) {
+ for (found = i = 0; !found && authmethods[i] != NULL; i++) {
+ if ((p = strchr(method, ':')) != NULL)
+ *p = '\0';
+ if (strcmp(method, authmethods[i]->name) != 0)
+ continue;
+ if (need_enable) {
+ if (authmethods[i]->enabled == NULL ||
+ *(authmethods[i]->enabled) == 0) {
+ error("Disabled method \"%s\" in "
+ "AuthenticationMethods list \"%s\"",
+ method, _methods);
+ goto out;
+ }
+ }
+ found = 1;
+ break;
+ }
+ if (!found) {
+ error("Unknown authentication method \"%s\" in list",
+ method);
+ goto out;
+ }
+ }
+ ret = 0;
+ out:
+ free(omethods);
+ return ret;
+}
+
+/*
+ * Prune the AuthenticationMethods supplied in the configuration, removing
+ * any methods lists that include disabled methods. Note that this might
+ * leave authctxt->num_auth_methods == 0, even when multiple required auth
+ * has been requested. For this reason, all tests for whether multiple is
+ * enabled should consult options.num_auth_methods directly.
+ */
+int
+auth2_setup_methods_lists(Authctxt *authctxt)
+{
+ u_int i;
+
+ if (options.num_auth_methods == 0)
+ return 0;
+ debug3("%s: checking methods", __func__);
+ authctxt->auth_methods = xcalloc(options.num_auth_methods,
+ sizeof(*authctxt->auth_methods));
+ authctxt->num_auth_methods = 0;
+ for (i = 0; i < options.num_auth_methods; i++) {
+ if (auth2_methods_valid(options.auth_methods[i], 1) != 0) {
+ logit("Authentication methods list \"%s\" contains "
+ "disabled method, skipping",
+ options.auth_methods[i]);
+ continue;
+ }
+ debug("authentication methods list %d: %s",
+ authctxt->num_auth_methods, options.auth_methods[i]);
+ authctxt->auth_methods[authctxt->num_auth_methods++] =
+ xstrdup(options.auth_methods[i]);
+ }
+ if (authctxt->num_auth_methods == 0) {
+ error("No AuthenticationMethods left after eliminating "
+ "disabled methods");
+ return -1;
+ }
+ return 0;
+}
+
+static int
+list_starts_with(const char *methods, const char *method,
+ const char *submethod)
+{
+ size_t l = strlen(method);
+ int match;
+ const char *p;
+
+ if (strncmp(methods, method, l) != 0)
+ return MATCH_NONE;
+ p = methods + l;
+ match = MATCH_METHOD;
+ if (*p == ':') {
+ if (!submethod)
+ return MATCH_PARTIAL;
+ l = strlen(submethod);
+ p += 1;
+ if (strncmp(submethod, p, l))
+ return MATCH_NONE;
+ p += l;
+ match = MATCH_BOTH;
+ }
+ if (*p != ',' && *p != '\0')
+ return MATCH_NONE;
+ return match;
+}
+
+/*
+ * Remove method from the start of a comma-separated list of methods.
+ * Returns 0 if the list of methods did not start with that method or 1
+ * if it did.
+ */
+static int
+remove_method(char **methods, const char *method, const char *submethod)
+{
+ char *omethods = *methods, *p;
+ size_t l = strlen(method);
+ int match;
+
+ match = list_starts_with(omethods, method, submethod);
+ if (match != MATCH_METHOD && match != MATCH_BOTH)
+ return 0;
+ p = omethods + l;
+ if (submethod && match == MATCH_BOTH)
+ p += 1 + strlen(submethod); /* include colon */
+ if (*p == ',')
+ p++;
+ *methods = xstrdup(p);
+ free(omethods);
+ return 1;
+}
+
+/*
+ * Called after successful authentication. Will remove the successful method
+ * from the start of each list in which it occurs. If it was the last method
+ * in any list, then authentication is deemed successful.
+ * Returns 1 if the method completed any authentication list or 0 otherwise.
+ */
+int
+auth2_update_methods_lists(Authctxt *authctxt, const char *method,
+ const char *submethod)
+{
+ u_int i, found = 0;
+
+ debug3("%s: updating methods list after \"%s\"", __func__, method);
+ for (i = 0; i < authctxt->num_auth_methods; i++) {
+ if (!remove_method(&(authctxt->auth_methods[i]), method,
+ submethod))
+ continue;
+ found = 1;
+ if (*authctxt->auth_methods[i] == '\0') {
+ debug2("authentication methods list %d complete", i);
+ return 1;
+ }
+ debug3("authentication methods list %d remaining: \"%s\"",
+ i, authctxt->auth_methods[i]);
+ }
+ /* This should not happen, but would be bad if it did */
+ if (!found)
+ fatal("%s: method not in AuthenticationMethods", __func__);
+ return 0;
+}
+
+