1 files changed, 79 insertions, 52 deletions

diff --git a/auth2.c b/auth2.c
index 3035926ba..d60e7f1f2 100644
--- a/auth2.c
+++ b/auth2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2.c,v 1.149 2018/07/11 18:53:29 markus Exp $ */
+/* $OpenBSD: auth2.c,v 1.155 2019/03/25 22:34:52 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -35,6 +35,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <unistd.h>
+#include <time.h>
 
 #include "atomicio.h"
 #include "xmalloc.h"
@@ -139,18 +140,21 @@ auth2_read_banner(void)
         return (banner);
 }
 
-void
-userauth_send_banner(const char *msg)
+static void
+userauth_send_banner(struct ssh *ssh, const char *msg)
 {
-        packet_start(SSH2_MSG_USERAUTH_BANNER);
-        packet_put_cstring(msg);
-        packet_put_cstring("");         /* language, unused */
-        packet_send();
+        int r;
+
+        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_BANNER)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, msg)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, "")) != 0 ||   /* language, unused */
+            (r = sshpkt_send(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
         debug("%s: sent", __func__);
 }
 
 static void
-userauth_banner(void)
+userauth_banner(struct ssh *ssh)
 {
         char *banner = NULL;
 
@@ -159,7 +163,7 @@ userauth_banner(void)
 
         if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
                 goto done;
-        userauth_send_banner(banner);
+        userauth_send_banner(ssh, banner);
 
 done:
         free(banner);
@@ -169,10 +173,10 @@ done:
  * loop until authctxt->success == TRUE
  */
 void
-do_authentication2(Authctxt *authctxt)
+do_authentication2(struct ssh *ssh)
 {
-        struct ssh *ssh = active_state;         /* XXX */
-        ssh->authctxt = authctxt;               /* XXX move to caller */
+        Authctxt *authctxt = ssh->authctxt;
+
         ssh_dispatch_init(ssh, &dispatch_protocol_error);
         ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_REQUEST, &input_service_request);
         ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt->success);
@@ -184,10 +188,12 @@ static int
 input_service_request(int type, u_int32_t seq, struct ssh *ssh)
 {
         Authctxt *authctxt = ssh->authctxt;
-        u_int len;
-        int acceptit = 0;
-        char *service = packet_get_cstring(&len);
-        packet_check_eom();
+        char *service = NULL;
+        int r, acceptit = 0;
+
+        if ((r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
+            (r = sshpkt_get_end(ssh)) != 0)
+                goto out;
 
         if (authctxt == NULL)
                 fatal("input_service_request: no authctxt");
@@ -196,20 +202,24 @@ input_service_request(int type, u_int32_t seq, struct ssh *ssh)
                 if (!authctxt->success) {
                         acceptit = 1;
                         /* now we can handle user-auth requests */
-                        ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
+                        ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
+                            &input_userauth_request);
                 }
         }
         /* XXX all other service requests are denied */
 
         if (acceptit) {
-                packet_start(SSH2_MSG_SERVICE_ACCEPT);
-                packet_put_cstring(service);
-                packet_send();
-                packet_write_wait();
+                if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_ACCEPT)) != 0 ||
+                    (r = sshpkt_put_cstring(ssh, service)) != 0 ||
+                    (r = sshpkt_send(ssh)) != 0 ||
+                    (r = ssh_packet_write_wait(ssh)) != 0)
+                        goto out;
         } else {
                 debug("bad service request %s", service);
-                packet_disconnect("bad service request %s", service);
+                ssh_packet_disconnect(ssh, "bad service request %s", service);
         }
+        r = 0;
+ out:
         free(service);
         return 0;
 }
@@ -257,16 +267,17 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
 {
         Authctxt *authctxt = ssh->authctxt;
         Authmethod *m = NULL;
-        char *user, *service, *method, *style = NULL, *role = NULL;
-        int authenticated = 0;
+        char *user = NULL, *service = NULL, *method = NULL, *style = NULL, *role = NULL;
+        int r, authenticated = 0;
         double tstart = monotime_double();
 
         if (authctxt == NULL)
                 fatal("input_userauth_request: no authctxt");
 
-        user = packet_get_cstring(NULL);
-        service = packet_get_cstring(NULL);
-        method = packet_get_cstring(NULL);
+        if ((r = sshpkt_get_cstring(ssh, &user, NULL)) != 0 ||
+            (r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
+            (r = sshpkt_get_cstring(ssh, &method, NULL)) != 0)
+                goto out;
         debug("userauth-request for user %s service %s method %s", user, service, method);
         debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
 
@@ -280,7 +291,7 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
 
         if (authctxt->attempt++ == 0) {
                 /* setup auth context */
-                authctxt->pw = PRIVSEP(getpwnamallow(user));
+                authctxt->pw = PRIVSEP(getpwnamallow(ssh, user));
                 authctxt->user = xstrdup(user);
                 if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
                         authctxt->valid = 1;
@@ -290,12 +301,12 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
                         /* Invalid user, fake password information */
                         authctxt->pw = fakepw();
 #ifdef SSH_AUDIT_EVENTS
-                        PRIVSEP(audit_event(SSH_INVALID_USER));
+                        PRIVSEP(audit_event(ssh, SSH_INVALID_USER));
 #endif
                 }
 #ifdef USE_PAM
                 if (options.use_pam)
-                        PRIVSEP(start_pam(authctxt));
+                        PRIVSEP(start_pam(ssh));
 #endif
                 ssh_packet_set_log_preamble(ssh, "%suser %s",
                     authctxt->valid ? "authenticating " : "invalid ", user);
@@ -306,13 +317,14 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
                 authctxt->role = role ? xstrdup(role) : NULL;
                 if (use_privsep)
                         mm_inform_authserv(service, style, role);
-                userauth_banner();
+                userauth_banner(ssh);
                 if (auth2_setup_methods_lists(authctxt) != 0)
-                        packet_disconnect("no authentication methods enabled");
+                        ssh_packet_disconnect(ssh,
+                            "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: "
-                    "(%s,%s) -> (%s,%s)",
+                ssh_packet_disconnect(ssh, "Change of username or service "
+                    "not allowed: (%s,%s) -> (%s,%s)",
                     authctxt->user, authctxt->service, user, service);
         }
         /* reset state */
@@ -338,11 +350,12 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
                 ensure_minimum_time_since(tstart,
                     user_specific_delay(authctxt->user));
         userauth_finish(ssh, authenticated, method, NULL);
-
+        r = 0;
+ out:
         free(service);
         free(user);
         free(method);
-        return 0;
+        return r;
 }
 
 void
@@ -351,7 +364,7 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
 {
         Authctxt *authctxt = ssh->authctxt;
         char *methods;
-        int partial = 0;
+        int r, partial = 0;
 
         if (!authctxt->valid && authenticated)
                 fatal("INTERNAL ERROR: authenticated invalid user %s",
@@ -364,7 +377,7 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
             !auth_root_allowed(ssh, method)) {
                 authenticated = 0;
 #ifdef SSH_AUDIT_EVENTS
-                PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
+                PRIVSEP(audit_event(ssh, SSH_LOGIN_ROOT_DENIED));
 #endif
         }
 
@@ -376,7 +389,7 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
         }
 
         /* Log before sending the reply */
-        auth_log(authctxt, authenticated, partial, method, submethod);
+        auth_log(ssh, authenticated, partial, method, submethod);
 
         /* Update information exposed to session */
         if (authenticated || partial)
@@ -395,8 +408,11 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
                                 if ((r = sshbuf_put(loginmsg, "\0", 1)) != 0)
                                         fatal("%s: buffer error: %s",
                                             __func__, ssh_err(r));
-                                userauth_send_banner(sshbuf_ptr(loginmsg));
-                                packet_write_wait();
+                                userauth_send_banner(ssh, sshbuf_ptr(loginmsg));
+                                if ((r = ssh_packet_write_wait(ssh)) != 0) {
+                                        sshpkt_fatal(ssh, r,
+                                            "%s: send PAM banner", __func__);
+                                }
                         }
                         fatal("Access denied for user %s by PAM account "
                             "configuration", authctxt->user);
@@ -406,10 +422,12 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
 
         if (authenticated == 1) {
                 /* turn off userauth */
-                ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
-                packet_start(SSH2_MSG_USERAUTH_SUCCESS);
-                packet_send();
-                packet_write_wait();
+                ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
+                    &dispatch_protocol_ignore);
+                if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_SUCCESS)) != 0 ||
+                    (r = sshpkt_send(ssh)) != 0 ||
+                    (r = ssh_packet_write_wait(ssh)) != 0)
+                        fatal("%s: %s", __func__, ssh_err(r));
                 /* now we can break out */
                 authctxt->success = 1;
                 ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
@@ -420,18 +438,19 @@ userauth_finish(struct ssh *ssh, int authenticated, const char *method,
                         authctxt->failures++;
                 if (authctxt->failures >= options.max_authtries) {
 #ifdef SSH_AUDIT_EVENTS
-                        PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
+                        PRIVSEP(audit_event(ssh, SSH_LOGIN_EXCEED_MAXTRIES));
 #endif
-                        auth_maxtries_exceeded(authctxt);
+                        auth_maxtries_exceeded(ssh);
                 }
                 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(partial);
-                packet_send();
-                packet_write_wait();
+                if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_FAILURE)) != 0 ||
+                    (r = sshpkt_put_cstring(ssh, methods)) != 0 ||
+                    (r = sshpkt_put_u8(ssh, partial)) != 0 ||
+                    (r = sshpkt_send(ssh)) != 0 ||
+                    (r = ssh_packet_write_wait(ssh)) != 0)
+                        fatal("%s: %s", __func__, ssh_err(r));
                 free(methods);
         }
 }
@@ -566,6 +585,14 @@ auth2_setup_methods_lists(Authctxt *authctxt)
 {
         u_int i;
 
+        /* First, normalise away the "any" pseudo-method */
+        if (options.num_auth_methods == 1 &&
+            strcmp(options.auth_methods[0], "any") == 0) {
+                free(options.auth_methods[0]);
+                options.auth_methods[0] = NULL;
+                options.num_auth_methods = 0;
+        }
+
         if (options.num_auth_methods == 0)
                 return 0;
         debug3("%s: checking methods", __func__);