upstream: sshd: switch GSSAPI to sshbuf API; ok djm@

OpenBSD-Commit-ID: e48449ab4be3f006f7ba33c66241b7d652973e30

1 files changed, 55 insertions, 40 deletions

diff --git a/auth2-gss.c b/auth2-gss.c
index 589283b72..a6f2a7125 100644
--- a/auth2-gss.c
+++ b/auth2-gss.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-gss.c,v 1.26 2017/06/24 06:34:38 djm Exp $ */
+/* $OpenBSD: auth2-gss.c,v 1.27 2018/07/09 21:37:55 markus Exp $ */
 
 /*
  * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@@ -33,13 +33,14 @@
 #include <stdarg.h>
 
 #include "xmalloc.h"
-#include "key.h"
+#include "sshkey.h"
 #include "hostfile.h"
 #include "auth.h"
 #include "ssh2.h"
 #include "log.h"
 #include "dispatch.h"
-#include "buffer.h"
+#include "sshbuf.h"
+#include "ssherr.h"
 #include "misc.h"
 #include "servconf.h"
 #include "packet.h"
@@ -63,16 +64,18 @@ userauth_gssapi(struct ssh *ssh)
         Authctxt *authctxt = ssh->authctxt;
         gss_OID_desc goid = {0, NULL};
         Gssctxt *ctxt = NULL;
-        int mechs;
-        int present;
+        int r, present;
+        u_int mechs;
         OM_uint32 ms;
-        u_int len;
+        size_t len;
         u_char *doid = NULL;
 
         if (!authctxt->valid || authctxt->user == NULL)
                 return (0);
 
-        mechs = packet_get_int();
+        if ((r = sshpkt_get_u32(ssh, &mechs)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
+
         if (mechs == 0) {
                 debug("Mechanism negotiation is not supported");
                 return (0);
@@ -84,7 +87,8 @@ userauth_gssapi(struct ssh *ssh)
                 free(doid);
 
                 present = 0;
-                doid = packet_get_string(&len);
+                if ((r = sshpkt_get_string(ssh, &doid, &len)) != 0)
+                        fatal("%s: %s", __func__, ssh_err(r));
 
                 if (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
                     doid[1] == len - 2) {
@@ -112,12 +116,12 @@ userauth_gssapi(struct ssh *ssh)
 
         authctxt->methoddata = (void *)ctxt;
 
-        packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
-
         /* Return the OID that we received */
-        packet_put_string(doid, len);
+        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE)) != 0 ||
+            (r = sshpkt_put_string(ssh, doid, len)) != 0 ||
+            (r = sshpkt_send(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 
-        packet_send();
         free(doid);
 
         ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
@@ -135,36 +139,45 @@ input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
         gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
         gss_buffer_desc recv_tok;
         OM_uint32 maj_status, min_status, flags;
-        u_int len;
+        u_char *p;
+        size_t len;
+        int r;
 
         if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
                 fatal("No authentication or GSSAPI context");
 
         gssctxt = authctxt->methoddata;
-        recv_tok.value = packet_get_string(&len);
-        recv_tok.length = len; /* u_int vs. size_t */
-
-        packet_check_eom();
+        if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
+            (r = sshpkt_get_end(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 
+        recv_tok.value = p;
+        recv_tok.length = len;
         maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
             &send_tok, &flags));
 
-        free(recv_tok.value);
+        free(p);
 
         if (GSS_ERROR(maj_status)) {
                 if (send_tok.length != 0) {
-                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
-                        packet_put_string(send_tok.value, send_tok.length);
-                        packet_send();
+                        if ((r = sshpkt_start(ssh,
+                            SSH2_MSG_USERAUTH_GSSAPI_ERRTOK)) != 0 ||
+                            (r = sshpkt_put_string(ssh, send_tok.value,
+                            send_tok.length)) != 0 ||
+                            (r = sshpkt_send(ssh)) != 0)
+                                fatal("%s: %s", __func__, ssh_err(r));
                 }
                 authctxt->postponed = 0;
                 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
                 userauth_finish(ssh, 0, "gssapi-with-mic", NULL);
         } else {
                 if (send_tok.length != 0) {
-                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
-                        packet_put_string(send_tok.value, send_tok.length);
-                        packet_send();
+                        if ((r = sshpkt_start(ssh,
+                            SSH2_MSG_USERAUTH_GSSAPI_TOKEN)) != 0 ||
+                            (r = sshpkt_put_string(ssh, send_tok.value,
+                            send_tok.length)) != 0 ||
+                            (r = sshpkt_send(ssh)) != 0)
+                                fatal("%s: %s", __func__, ssh_err(r));
                 }
                 if (maj_status == GSS_S_COMPLETE) {
                         ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
@@ -190,16 +203,16 @@ input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
         gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
         gss_buffer_desc recv_tok;
         OM_uint32 maj_status;
-        u_int len;
+        int r;
 
         if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
                 fatal("No authentication or GSSAPI context");
 
         gssctxt = authctxt->methoddata;
-        recv_tok.value = packet_get_string(&len);
-        recv_tok.length = len;
-
-        packet_check_eom();
+        if ((r = sshpkt_get_string(ssh,
+            &recv_tok.value, &recv_tok.length)) != 0 ||
+            (r = sshpkt_get_end(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 
         /* Push the error token into GSSAPI to see what it says */
         maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
@@ -238,7 +251,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh)
          * the dispatcher once the exchange is complete
          */
 
-        packet_check_eom();
+        if ((r = sshpkt_get_end(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 
         authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
 
@@ -260,10 +274,9 @@ input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh)
 {
         Authctxt *authctxt = ssh->authctxt;
         Gssctxt *gssctxt;
-        int authenticated = 0;
-        Buffer b;
+        int r, authenticated = 0;
+        struct sshbuf *b;
         gss_buffer_desc mic, gssbuf;
-        u_int len;
         const char *displayname;
 
         if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
@@ -271,21 +284,23 @@ input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh)
 
         gssctxt = authctxt->methoddata;
 
-        mic.value = packet_get_string(&len);
-        mic.length = len;
-
-        ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+        if ((r = sshpkt_get_string(ssh, &mic.value, &mic.length)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
+        if ((b = sshbuf_new()) == NULL)
+                fatal("%s: sshbuf_new failed", __func__);
+        ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
             "gssapi-with-mic");
 
-        gssbuf.value = buffer_ptr(&b);
-        gssbuf.length = buffer_len(&b);
+        if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
+                fatal("%s: sshbuf_mutable_ptr failed", __func__);
+        gssbuf.length = sshbuf_len(b);
 
         if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
                 authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
         else
                 logit("GSSAPI MIC check failed");
 
-        buffer_free(&b);
+        sshbuf_free(b);
         free(mic.value);
 
         if ((!use_privsep || mm_is_monitor()) &&