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

OpenBSD-Commit-ID: e48449ab4be3f006f7ba33c66241b7d652973e30
This commit is contained in:
markus@openbsd.org 2018-07-09 21:37:55 +00:00 committed by Damien Miller
parent c7d39ac8dc
commit b8d9214d96
4 changed files with 86 additions and 65 deletions

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@ -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. * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@ -33,13 +33,14 @@
#include <stdarg.h> #include <stdarg.h>
#include "xmalloc.h" #include "xmalloc.h"
#include "key.h" #include "sshkey.h"
#include "hostfile.h" #include "hostfile.h"
#include "auth.h" #include "auth.h"
#include "ssh2.h" #include "ssh2.h"
#include "log.h" #include "log.h"
#include "dispatch.h" #include "dispatch.h"
#include "buffer.h" #include "sshbuf.h"
#include "ssherr.h"
#include "misc.h" #include "misc.h"
#include "servconf.h" #include "servconf.h"
#include "packet.h" #include "packet.h"
@ -63,16 +64,18 @@ userauth_gssapi(struct ssh *ssh)
Authctxt *authctxt = ssh->authctxt; Authctxt *authctxt = ssh->authctxt;
gss_OID_desc goid = {0, NULL}; gss_OID_desc goid = {0, NULL};
Gssctxt *ctxt = NULL; Gssctxt *ctxt = NULL;
int mechs; int r, present;
int present; u_int mechs;
OM_uint32 ms; OM_uint32 ms;
u_int len; size_t len;
u_char *doid = NULL; u_char *doid = NULL;
if (!authctxt->valid || authctxt->user == NULL) if (!authctxt->valid || authctxt->user == NULL)
return (0); return (0);
mechs = packet_get_int(); if ((r = sshpkt_get_u32(ssh, &mechs)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
if (mechs == 0) { if (mechs == 0) {
debug("Mechanism negotiation is not supported"); debug("Mechanism negotiation is not supported");
return (0); return (0);
@ -84,7 +87,8 @@ userauth_gssapi(struct ssh *ssh)
free(doid); free(doid);
present = 0; 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 && if (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
doid[1] == len - 2) { doid[1] == len - 2) {
@ -112,12 +116,12 @@ userauth_gssapi(struct ssh *ssh)
authctxt->methoddata = (void *)ctxt; authctxt->methoddata = (void *)ctxt;
packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
/* Return the OID that we received */ /* 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); free(doid);
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); 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 send_tok = GSS_C_EMPTY_BUFFER;
gss_buffer_desc recv_tok; gss_buffer_desc recv_tok;
OM_uint32 maj_status, min_status, flags; 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)) if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
fatal("No authentication or GSSAPI context"); fatal("No authentication or GSSAPI context");
gssctxt = authctxt->methoddata; gssctxt = authctxt->methoddata;
recv_tok.value = packet_get_string(&len); if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
recv_tok.length = len; /* u_int vs. size_t */ (r = sshpkt_get_end(ssh)) != 0)
fatal("%s: %s", __func__, ssh_err(r));
packet_check_eom();
recv_tok.value = p;
recv_tok.length = len;
maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
&send_tok, &flags)); &send_tok, &flags));
free(recv_tok.value); free(p);
if (GSS_ERROR(maj_status)) { if (GSS_ERROR(maj_status)) {
if (send_tok.length != 0) { if (send_tok.length != 0) {
packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); if ((r = sshpkt_start(ssh,
packet_put_string(send_tok.value, send_tok.length); SSH2_MSG_USERAUTH_GSSAPI_ERRTOK)) != 0 ||
packet_send(); (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; authctxt->postponed = 0;
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
userauth_finish(ssh, 0, "gssapi-with-mic", NULL); userauth_finish(ssh, 0, "gssapi-with-mic", NULL);
} else { } else {
if (send_tok.length != 0) { if (send_tok.length != 0) {
packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); if ((r = sshpkt_start(ssh,
packet_put_string(send_tok.value, send_tok.length); SSH2_MSG_USERAUTH_GSSAPI_TOKEN)) != 0 ||
packet_send(); (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) { if (maj_status == GSS_S_COMPLETE) {
ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); 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 send_tok = GSS_C_EMPTY_BUFFER;
gss_buffer_desc recv_tok; gss_buffer_desc recv_tok;
OM_uint32 maj_status; OM_uint32 maj_status;
u_int len; int r;
if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
fatal("No authentication or GSSAPI context"); fatal("No authentication or GSSAPI context");
gssctxt = authctxt->methoddata; gssctxt = authctxt->methoddata;
recv_tok.value = packet_get_string(&len); if ((r = sshpkt_get_string(ssh,
recv_tok.length = len; &recv_tok.value, &recv_tok.length)) != 0 ||
(r = sshpkt_get_end(ssh)) != 0)
packet_check_eom(); fatal("%s: %s", __func__, ssh_err(r));
/* Push the error token into GSSAPI to see what it says */ /* Push the error token into GSSAPI to see what it says */
maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, 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 * 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)); 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; Authctxt *authctxt = ssh->authctxt;
Gssctxt *gssctxt; Gssctxt *gssctxt;
int authenticated = 0; int r, authenticated = 0;
Buffer b; struct sshbuf *b;
gss_buffer_desc mic, gssbuf; gss_buffer_desc mic, gssbuf;
u_int len;
const char *displayname; const char *displayname;
if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) 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; gssctxt = authctxt->methoddata;
mic.value = packet_get_string(&len); if ((r = sshpkt_get_string(ssh, &mic.value, &mic.length)) != 0)
mic.length = len; fatal("%s: %s", __func__, ssh_err(r));
if ((b = sshbuf_new()) == NULL)
ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service, fatal("%s: sshbuf_new failed", __func__);
ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
"gssapi-with-mic"); "gssapi-with-mic");
gssbuf.value = buffer_ptr(&b); if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
gssbuf.length = buffer_len(&b); fatal("%s: sshbuf_mutable_ptr failed", __func__);
gssbuf.length = sshbuf_len(b);
if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic)))) if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
else else
logit("GSSAPI MIC check failed"); logit("GSSAPI MIC check failed");
buffer_free(&b); sshbuf_free(b);
free(mic.value); free(mic.value);
if ((!use_privsep || mm_is_monitor()) && if ((!use_privsep || mm_is_monitor()) &&

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@ -1,4 +1,4 @@
/* $OpenBSD: gss-genr.c,v 1.24 2016/09/12 01:22:38 deraadt Exp $ */ /* $OpenBSD: gss-genr.c,v 1.25 2018/07/09 21:37:55 markus Exp $ */
/* /*
* Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved. * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
@ -37,7 +37,8 @@
#include <unistd.h> #include <unistd.h>
#include "xmalloc.h" #include "xmalloc.h"
#include "buffer.h" #include "ssherr.h"
#include "sshbuf.h"
#include "log.h" #include "log.h"
#include "ssh2.h" #include "ssh2.h"
@ -94,10 +95,12 @@ ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
OM_uint32 lmin; OM_uint32 lmin;
gss_buffer_desc msg = GSS_C_EMPTY_BUFFER; gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
OM_uint32 ctx; OM_uint32 ctx;
Buffer b; struct sshbuf *b;
char *ret; char *ret;
int r;
buffer_init(&b); if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if (major_status != NULL) if (major_status != NULL)
*major_status = ctxt->major; *major_status = ctxt->major;
@ -110,8 +113,9 @@ ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
gss_display_status(&lmin, ctxt->major, gss_display_status(&lmin, ctxt->major,
GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg); GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg);
buffer_append(&b, msg.value, msg.length); if ((r = sshbuf_put(b, msg.value, msg.length)) != 0 ||
buffer_put_char(&b, '\n'); (r = sshbuf_put_u8(b, '\n')) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
gss_release_buffer(&lmin, &msg); gss_release_buffer(&lmin, &msg);
} while (ctx != 0); } while (ctx != 0);
@ -121,16 +125,17 @@ ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
gss_display_status(&lmin, ctxt->minor, gss_display_status(&lmin, ctxt->minor,
GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg); GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg);
buffer_append(&b, msg.value, msg.length); if ((r = sshbuf_put(b, msg.value, msg.length)) != 0 ||
buffer_put_char(&b, '\n'); (r = sshbuf_put_u8(b, '\n')) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
gss_release_buffer(&lmin, &msg); gss_release_buffer(&lmin, &msg);
} while (ctx != 0); } while (ctx != 0);
buffer_put_char(&b, '\0'); if ((r = sshbuf_put_u8(b, '\n')) != 0)
ret = xmalloc(buffer_len(&b)); fatal("%s: buffer error: %s", __func__, ssh_err(r));
buffer_get(&b, ret, buffer_len(&b)); ret = xstrdup((const char *)sshbuf_ptr(b));
buffer_free(&b); sshbuf_free(b);
return (ret); return (ret);
} }
@ -238,15 +243,18 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
} }
void void
ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service, ssh_gssapi_buildmic(struct sshbuf *b, const char *user, const char *service,
const char *context) const char *context)
{ {
buffer_init(b); int r;
buffer_put_string(b, session_id2, session_id2_len);
buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST); sshbuf_reset(b);
buffer_put_cstring(b, user); if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
buffer_put_cstring(b, service); (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
buffer_put_cstring(b, context); (r = sshbuf_put_cstring(b, user)) != 0 ||
(r = sshbuf_put_cstring(b, service)) != 0 ||
(r = sshbuf_put_cstring(b, context)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
} }
int int

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@ -1,4 +1,4 @@
/* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */ /* $OpenBSD: gss-serv-krb5.c,v 1.9 2018/07/09 21:37:55 markus Exp $ */
/* /*
* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@ -35,14 +35,13 @@
#include <string.h> #include <string.h>
#include "xmalloc.h" #include "xmalloc.h"
#include "key.h" #include "sshkey.h"
#include "hostfile.h" #include "hostfile.h"
#include "auth.h" #include "auth.h"
#include "log.h" #include "log.h"
#include "misc.h" #include "misc.h"
#include "servconf.h" #include "servconf.h"
#include "buffer.h"
#include "ssh-gss.h" #include "ssh-gss.h"
extern ServerOptions options; extern ServerOptions options;

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@ -1,4 +1,4 @@
/* $OpenBSD: gss-serv.c,v 1.30 2017/06/24 06:34:38 djm Exp $ */ /* $OpenBSD: gss-serv.c,v 1.31 2018/07/09 21:37:55 markus Exp $ */
/* /*
* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@ -36,8 +36,7 @@
#include "openbsd-compat/sys-queue.h" #include "openbsd-compat/sys-queue.h"
#include "xmalloc.h" #include "xmalloc.h"
#include "buffer.h" #include "sshkey.h"
#include "key.h"
#include "hostfile.h" #include "hostfile.h"
#include "auth.h" #include "auth.h"
#include "log.h" #include "log.h"