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

OpenBSD-Commit-ID: 880aa06bce4b140781e836bb56bec34873290641

1 files changed, 40 insertions, 29 deletions

diff --git a/auth2-chall.c b/auth2-chall.c
index 11c8d31b3..5edd0e653 100644
--- a/auth2-chall.c
+++ b/auth2-chall.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-chall.c,v 1.48 2017/05/30 14:29:59 markus Exp $ */
+/* $OpenBSD: auth2-chall.c,v 1.49 2018/07/09 21:35:50 markus Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2001 Per Allansson.  All rights reserved.
@@ -34,12 +34,13 @@
 
 #include "xmalloc.h"
 #include "ssh2.h"
-#include "key.h"
+#include "sshkey.h"
 #include "hostfile.h"
 #include "auth.h"
-#include "buffer.h"
+#include "sshbuf.h"
 #include "packet.h"
 #include "dispatch.h"
+#include "ssherr.h"
 #include "log.h"
 #include "misc.h"
 #include "servconf.h"
@@ -48,7 +49,7 @@
 extern ServerOptions options;
 
 static int auth2_challenge_start(struct ssh *);
-static int send_userauth_info_request(Authctxt *);
+static int send_userauth_info_request(struct ssh *);
 static int input_userauth_info_response(int, u_int32_t, struct ssh *);
 
 #ifdef BSD_AUTH
@@ -105,8 +106,8 @@ static KbdintAuthctxt *
 kbdint_alloc(const char *devs)
 {
         KbdintAuthctxt *kbdintctxt;
-        Buffer b;
-        int i;
+        struct sshbuf *b;
+        int i, r;
 
 #ifdef USE_PAM
         if (!options.use_pam)
@@ -115,16 +116,17 @@ kbdint_alloc(const char *devs)
 
         kbdintctxt = xcalloc(1, sizeof(KbdintAuthctxt));
         if (strcmp(devs, "") == 0) {
-                buffer_init(&b);
+                if ((b = sshbuf_new()) == NULL)
+                        fatal("%s: sshbuf_new failed", __func__);
                 for (i = 0; devices[i]; i++) {
-                        if (buffer_len(&b) > 0)
-                                buffer_append(&b, ",", 1);
-                        buffer_append(&b, devices[i]->name,
-                            strlen(devices[i]->name));
+                        if ((r = sshbuf_putf(b, "%s%s",
+                            sshbuf_len(b) ? "," : "", devices[i]->name)) != 0)
+                                fatal("%s: buffer error: %s",
+                                    __func__, ssh_err(r));
                 }
-                if ((kbdintctxt->devices = sshbuf_dup_string(&b)) == NULL)
+                if ((kbdintctxt->devices = sshbuf_dup_string(b)) == NULL)
                         fatal("%s: sshbuf_dup_string failed", __func__);
-                buffer_free(&b);
+                sshbuf_free(b);
         } else {
                 kbdintctxt->devices = xstrdup(devs);
         }
@@ -243,7 +245,7 @@ auth2_challenge_start(struct ssh *ssh)
                 auth2_challenge_stop(ssh);
                 return 0;
         }
-        if (send_userauth_info_request(authctxt) == 0) {
+        if (send_userauth_info_request(ssh) == 0) {
                 auth2_challenge_stop(ssh);
                 return 0;
         }
@@ -255,28 +257,32 @@ auth2_challenge_start(struct ssh *ssh)
 }
 
 static int
-send_userauth_info_request(Authctxt *authctxt)
+send_userauth_info_request(struct ssh *ssh)
 {
+        Authctxt *authctxt = ssh->authctxt;
         KbdintAuthctxt *kbdintctxt;
         char *name, *instr, **prompts;
-        u_int i, *echo_on;
+        u_int r, i, *echo_on;
 
         kbdintctxt = authctxt->kbdintctxt;
         if (kbdintctxt->device->query(kbdintctxt->ctxt,
             &name, &instr, &kbdintctxt->nreq, &prompts, &echo_on))
                 return 0;
 
-        packet_start(SSH2_MSG_USERAUTH_INFO_REQUEST);
-        packet_put_cstring(name);
-        packet_put_cstring(instr);
-        packet_put_cstring("");         /* language not used */
-        packet_put_int(kbdintctxt->nreq);
+        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, name)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, instr)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, "")) != 0 ||   /* language not used */
+            (r = sshpkt_put_u32(ssh, kbdintctxt->nreq)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
         for (i = 0; i < kbdintctxt->nreq; i++) {
-                packet_put_cstring(prompts[i]);
-                packet_put_char(echo_on[i]);
+                if ((r = sshpkt_put_cstring(ssh, prompts[i])) != 0 ||
+                    (r = sshpkt_put_u8(ssh, echo_on[i])) != 0)
+                        fatal("%s: %s", __func__, ssh_err(r));
         }
-        packet_send();
-        packet_write_wait();
+        if ((r = sshpkt_send(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
+        ssh_packet_write_wait(ssh);
 
         for (i = 0; i < kbdintctxt->nreq; i++)
                 free(prompts[i]);
@@ -293,6 +299,7 @@ input_userauth_info_response(int type, u_int32_t seq, struct ssh *ssh)
         Authctxt *authctxt = ssh->authctxt;
         KbdintAuthctxt *kbdintctxt;
         int authenticated = 0, res;
+        int r;
         u_int i, nresp;
         const char *devicename = NULL;
         char **response = NULL;
@@ -306,7 +313,8 @@ input_userauth_info_response(int type, u_int32_t seq, struct ssh *ssh)
                 fatal("input_userauth_info_response: no device");
 
         authctxt->postponed = 0;        /* reset */
-        nresp = packet_get_int();
+        if ((r = sshpkt_get_u32(ssh, &nresp)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
         if (nresp != kbdintctxt->nreq)
                 fatal("input_userauth_info_response: wrong number of replies");
         if (nresp > 100)
@@ -314,9 +322,12 @@ input_userauth_info_response(int type, u_int32_t seq, struct ssh *ssh)
         if (nresp > 0) {
                 response = xcalloc(nresp, sizeof(char *));
                 for (i = 0; i < nresp; i++)
-                        response[i] = packet_get_string(NULL);
+                        if ((r = sshpkt_get_cstring(ssh, &response[i],
+                            NULL)) != 0)
+                                fatal("%s: %s", __func__, ssh_err(r));
         }
-        packet_check_eom();
+        if ((r = sshpkt_get_end(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 
         res = kbdintctxt->device->respond(kbdintctxt->ctxt, nresp, response);
 
@@ -333,7 +344,7 @@ input_userauth_info_response(int type, u_int32_t seq, struct ssh *ssh)
                 break;
         case 1:
                 /* Authentication needs further interaction */
-                if (send_userauth_info_request(authctxt) == 1)
+                if (send_userauth_info_request(ssh) == 1)
                         authctxt->postponed = 1;
                 break;
         default: