+/* $OpenBSD: sshconnect2.c,v 1.166 2008/07/17 08:48:00 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.135 2004/03/05 10:53:58 markus Exp $");
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H)
+#include <vis.h>
+#endif
#include "openbsd-compat/sys-queue.h"
+#include "xmalloc.h"
#include "ssh.h"
#include "ssh2.h"
-#include "xmalloc.h"
#include "buffer.h"
#include "packet.h"
#include "compat.h"
-#include "bufaux.h"
#include "cipher.h"
+#include "key.h"
#include "kex.h"
#include "myproposal.h"
#include "sshconnect.h"
#include "authfd.h"
#include "log.h"
#include "readconf.h"
-#include "readpass.h"
+#include "misc.h"
#include "match.h"
#include "dispatch.h"
#include "canohost.h"
#include "msg.h"
#include "pathnames.h"
+#include "uidswap.h"
#ifdef GSSAPI
#include "ssh-gss.h"
extern char *server_version_string;
extern Options options;
+/* tty_flag is set in ssh.c. use this in ssh_userauth2 */
+/* if it is set then prevent the switch to the null cipher */
+
+extern int tty_flag;
+
+/* tty_flag is set in ssh.c. use this in ssh_userauth2 */
+/* if it is set then prevent the switch to the null cipher */
+
+extern int tty_flag;
+
/*
* SSH2 key exchange
*/
ssh_kex2(char *host, struct sockaddr *hostaddr)
{
Kex *kex;
+
#ifdef GSSAPI
- char *orig, *gss;
- int len;
+ char *orig = NULL, *gss = NULL;
+ char *gss_host = NULL;
#endif
xxx_host = host;
#ifdef GSSAPI
if (options.gss_keyex) {
- /* Add the GSSAPI mechanisms currently supported on this client to
- * the key exchange algorithm proposal */
- orig = myproposal[PROPOSAL_KEX_ALGS];
- gss = ssh_gssapi_client_mechanisms((char *)get_canonical_hostname(1));
- if (gss) {
- len = strlen(orig)+strlen(gss)+2;
- myproposal[PROPOSAL_KEX_ALGS]=xmalloc(len);
- snprintf(myproposal[PROPOSAL_KEX_ALGS],len,"%s,%s",gss,orig);
- }
+ /* Add the GSSAPI mechanisms currently supported on this
+ * client to the key exchange algorithm proposal */
+ orig = myproposal[PROPOSAL_KEX_ALGS];
+
+ if (options.gss_trust_dns)
+ gss_host = (char *)get_canonical_hostname(1);
+ else
+ gss_host = host;
+
+ gss = ssh_gssapi_client_mechanisms(gss_host);
+ if (gss) {
+ debug("Offering GSSAPI proposal: %s", gss);
+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
+ "%s,%s", gss, orig);
+ }
}
#endif
compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
if (options.compression) {
myproposal[PROPOSAL_COMP_ALGS_CTOS] =
- myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
} else {
myproposal[PROPOSAL_COMP_ALGS_CTOS] =
- myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
}
if (options.macs != NULL) {
myproposal[PROPOSAL_MAC_ALGS_CTOS] =
options.hostkeyalgorithms;
#ifdef GSSAPI
- /* If we've got GSSAPI algorithms, then we also support the
- * 'null' hostkey, as a last resort */
+ /* If we've got GSSAPI algorithms, then we also support the
+ * 'null' hostkey, as a last resort */
if (options.gss_keyex && gss) {
- orig=myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
- len = strlen(orig)+sizeof(",null");
- myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]=xmalloc(len);
- snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],len,"%s,null",orig);
+ orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
+ xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],
+ "%s,null", orig);
}
#endif
if (options.rekey_limit)
- packet_set_rekey_limit(options.rekey_limit);
+ packet_set_rekey_limit((u_int32_t)options.rekey_limit);
/* start key exchange */
kex = kex_setup(myproposal);
kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
+ kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
+ kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
#ifdef GSSAPI
kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client;
#endif
kex->client_version_string=client_version_string;
kex->server_version_string=server_version_string;
kex->verify_host_key=&verify_host_key_callback;
+
#ifdef GSSAPI
- kex->options.gss_deleg_creds=options.gss_deleg_creds;
+ kex->gss_deleg_creds = options.gss_deleg_creds;
+ kex->gss_trust_dns = options.gss_trust_dns;
+ kex->gss_host = gss_host;
#endif
xxx_kex = kex;
int userauth_hostbased(Authctxt *);
int userauth_kerberos(Authctxt *);
-#ifdef GSSAPI
-int userauth_gssapi(Authctxt *authctxt);
-void input_gssapi_response(int type, u_int32_t, void *);
-void input_gssapi_token(int type, u_int32_t, void *);
-void input_gssapi_hash(int type, u_int32_t, void *);
-void input_gssapi_error(int, u_int32_t, void *);
-void input_gssapi_errtok(int, u_int32_t, void *);
-#endif
-
#ifdef GSSAPI
int userauth_external(Authctxt *authctxt);
int userauth_gssapi(Authctxt *authctxt);
void input_gssapi_hash(int type, u_int32_t, void *);
void input_gssapi_error(int, u_int32_t, void *);
void input_gssapi_errtok(int, u_int32_t, void *);
+int userauth_gsskeyex(Authctxt *authctxt);
#endif
void userauth(Authctxt *, char *);
Authmethod authmethods[] = {
#ifdef GSSAPI
+ {"gssapi-keyex",
+ userauth_gsskeyex,
+ &options.gss_authentication,
+ NULL},
{"external-keyx",
userauth_external,
&options.gss_authentication,
pubkey_cleanup(&authctxt);
dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
+ /* if the user wants to use the none cipher do it */
+ /* post authentication and only if the right conditions are met */
+ /* both of the NONE commands must be true and there must be no */
+ /* tty allocated */
+ if ((options.none_switch == 1) && (options.none_enabled == 1))
+ {
+ if (!tty_flag) /* no null on tty sessions */
+ {
+ debug("Requesting none rekeying...");
+ myproposal[PROPOSAL_ENC_ALGS_STOC] = "none";
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none";
+ kex_prop2buf(&xxx_kex->my,myproposal);
+ packet_request_rekeying();
+ fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n");
+ }
+ else
+ {
+ /* requested NONE cipher when in a tty */
+ debug("Cannot switch to NONE cipher with tty allocated");
+ fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n");
+ }
+ }
debug("Authentication succeeded (%s).", authctxt.method->name);
}
input_userauth_error(int type, u_int32_t seq, void *ctxt)
{
fatal("input_userauth_error: bad message during authentication: "
- "type %d", type);
+ "type %d", type);
}
void
input_userauth_banner(int type, u_int32_t seq, void *ctxt)
{
- char *msg, *lang;
+ char *msg, *raw, *lang;
+ u_int len;
debug3("input_userauth_banner");
- msg = packet_get_string(NULL);
+ raw = packet_get_string(&len);
lang = packet_get_string(NULL);
- if (options.log_level > SYSLOG_LEVEL_QUIET)
+ if (options.log_level >= SYSLOG_LEVEL_INFO) {
+ if (len > 65536)
+ len = 65536;
+ msg = xmalloc(len * 4); /* max expansion from strnvis() */
+ strnvis(msg, raw, len * 4, VIS_SAFE|VIS_OCTAL);
fprintf(stderr, "%s", msg);
- xfree(msg);
+ xfree(msg);
+ }
+ xfree(raw);
xfree(lang);
}
* moved to the end of the queue. this also avoids confusion by
* duplicate keys
*/
- TAILQ_FOREACH_REVERSE(id, &authctxt->keys, next, idlist) {
+ TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
if (key_equal(key, id->key)) {
sent = sign_and_send_pubkey(authctxt, id);
break;
{
Gssctxt *gssctxt = NULL;
static gss_OID_set gss_supported = NULL;
- static int mech = 0;
+ static u_int mech = 0;
OM_uint32 min;
int ok = 0;
+ char *gss_host = NULL;
if (!options.gss_authentication) {
verbose("GSSAPI authentication disabled.");
return 0;
}
+ if (options.gss_trust_dns)
+ gss_host = (char *)get_canonical_hostname(1);
+ else
+ gss_host = (char *)authctxt->host;
+
/* Try one GSSAPI method at a time, rather than sending them all at
* once. */
/* Check to see if the mechanism is usable before we offer it */
while (mech < gss_supported->count && !ok) {
- if (gssctxt)
- ssh_gssapi_delete_ctx(&gssctxt);
- ssh_gssapi_build_ctx(&gssctxt);
- ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
-
/* My DER encoding requires length<128 */
if (gss_supported->elements[mech].length < 128 &&
- !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
- authctxt->host))) {
+ ssh_gssapi_check_mechanism(&gssctxt,
+ &gss_supported->elements[mech], gss_host)) {
ok = 1; /* Mechanism works */
} else {
mech++;
}
}
- if (!ok) return 0;
+ if (!ok)
+ return 0;
authctxt->methoddata=(void *)gssctxt;
packet_put_int(1);
- /* Some servers encode the OID incorrectly (as we used to) */
- if (datafellows & SSH_BUG_GSSAPI_BER) {
- packet_put_string(gss_supported->elements[mech].elements,
- gss_supported->elements[mech].length);
- } else {
- packet_put_int((gss_supported->elements[mech].length)+2);
- packet_put_char(SSH_GSS_OIDTYPE);
- packet_put_char(gss_supported->elements[mech].length);
- packet_put_raw(gss_supported->elements[mech].elements,
- gss_supported->elements[mech].length);
- }
+ packet_put_int((gss_supported->elements[mech].length) + 2);
+ packet_put_char(SSH_GSS_OIDTYPE);
+ packet_put_char(gss_supported->elements[mech].length);
+ packet_put_raw(gss_supported->elements[mech].elements,
+ gss_supported->elements[mech].length);
packet_send();
Authctxt *authctxt = ctxt;
Gssctxt *gssctxt = authctxt->methoddata;
gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
- gss_buffer_desc gssbuf, mic;
+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+ gss_buffer_desc gssbuf;
OM_uint32 status, ms, flags;
Buffer b;
{
Authctxt *authctxt = ctxt;
Gssctxt *gssctxt;
- int oidlen;
- char *oidv;
+ u_int oidlen;
+ u_char *oidv;
if (authctxt == NULL)
fatal("input_gssapi_response: no authentication context");
/* Setup our OID */
oidv = packet_get_string(&oidlen);
- if (datafellows & SSH_BUG_GSSAPI_BER) {
- if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
- fatal("Server returned different OID than expected");
- } else {
- if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
- debug("Badly encoded mechanism OID received");
- userauth(authctxt, NULL);
- xfree(oidv);
- return;
- }
- if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
- fatal("Server returned different OID than expected");
+ if (oidlen <= 2 ||
+ oidv[0] != SSH_GSS_OIDTYPE ||
+ oidv[1] != oidlen - 2) {
+ xfree(oidv);
+ debug("Badly encoded mechanism OID received");
+ userauth(authctxt, NULL);
+ return;
}
+ if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
+ fatal("Server returned different OID than expected");
+
packet_check_eom();
xfree(oidv);
/* Stick it into GSSAPI and see what it says */
status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
- &recv_tok, &send_tok, NULL);
+ &recv_tok, &send_tok, NULL);
xfree(recv_tok.value);
gss_release_buffer(&ms, &send_tok);
packet_check_eom();
- debug("Server GSSAPI Error:\n%s\n", msg);
+ debug("Server GSSAPI Error:\n%s", msg);
xfree(msg);
xfree(lang);
}
+#ifdef GSI
+extern
+const gss_OID_desc * const gss_mech_globus_gssapi_openssl;
+#define is_gsi_oid(oid) \
+ (oid->length == gss_mech_globus_gssapi_openssl->length && \
+ (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \
+ oid->length) == 0))
+#endif
+
int
userauth_external(Authctxt *authctxt)
{
/* The client MUST NOT try this method if initial key exchange
was not performed using a GSSAPI-based key exchange
method. */
- if (xxx_kex->kex_type != KEX_GSS_GRP1_SHA1) {
+ if (gss_kex_context == NULL) {
debug2("gsskex not performed, skipping external-keyx");
return 0;
}
debug2("userauth_external");
packet_start(SSH2_MSG_USERAUTH_REQUEST);
#ifdef GSI
- if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) {
- packet_put_cstring("");
+ if (options.implicit && is_gsi_oid(gss_kex_context->oid)) {
+ packet_put_cstring("");
} else {
#endif
- packet_put_cstring(authctxt->server_user);
+ packet_put_cstring(authctxt->server_user);
#ifdef GSI
}
#endif
packet_write_wait();
return 1;
}
+int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+ Buffer b;
+ gss_buffer_desc gssbuf;
+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+ OM_uint32 ms;
+
+ static int attempt = 0;
+ if (attempt++ >= 1)
+ return (0);
+
+ if (gss_kex_context == NULL) {
+ debug("No valid Key exchange context");
+ return (0);
+ }
+
+#ifdef GSI
+ if (options.implicit && is_gsi_oid(gss_kex_context->oid)) {
+ ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex");
+ } else {
+#endif
+ ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
+ "gssapi-keyex");
+#ifdef GSI
+ }
+#endif
+
+ gssbuf.value = buffer_ptr(&b);
+ gssbuf.length = buffer_len(&b);
+
+ if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
+ buffer_free(&b);
+ return (0);
+ }
+
+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
+#ifdef GSI
+ if (options.implicit && is_gsi_oid(gss_kex_context->oid)) {
+ packet_put_cstring("");
+ } else {
+#endif
+ packet_put_cstring(authctxt->server_user);
+#ifdef GSI
+ }
+#endif
+ packet_put_cstring(authctxt->service);
+ packet_put_cstring(authctxt->method->name);
+ packet_put_string(mic.value, mic.length);
+ packet_send();
+
+ buffer_free(&b);
+ gss_release_buffer(&ms, &mic);
+
+ return (1);
+}
+
#endif /* GSSAPI */
int
{
Key *private;
char prompt[300], *passphrase;
- int quit, i;
+ int perm_ok, quit, i;
struct stat st;
if (stat(filename, &st) < 0) {
debug3("no such identity: %s", filename);
return NULL;
}
- private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
+ private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
+ if (!perm_ok)
+ return NULL;
if (private == NULL) {
if (options.batch_mode)
return NULL;
for (i = 0; i < options.number_of_password_prompts; i++) {
passphrase = read_passphrase(prompt, 0);
if (strcmp(passphrase, "") != 0) {
- private = key_load_private_type(KEY_UNSPEC, filename,
- passphrase, NULL);
+ private = key_load_private_type(KEY_UNSPEC,
+ filename, passphrase, NULL, NULL);
quit = 0;
} else {
debug2("no passphrase given, try next key");
if (key && key->type == KEY_RSA1)
continue;
options.identity_keys[i] = NULL;
- id = xmalloc(sizeof(*id));
- memset(id, 0, sizeof(*id));
+ id = xcalloc(1, sizeof(*id));
id->key = key;
id->filename = xstrdup(options.identity_files[i]);
TAILQ_INSERT_TAIL(&files, id, next);
}
}
if (!found && !options.identities_only) {
- id = xmalloc(sizeof(*id));
- memset(id, 0, sizeof(*id));
+ id = xcalloc(1, sizeof(*id));
id->key = key;
id->filename = comment;
id->ac = ac;
return -1;
}
if (pid == 0) {
- seteuid(getuid());
- setuid(getuid());
+ permanently_drop_suid(getuid());
close(from[0]);
if (dup2(from[1], STDOUT_FILENO) < 0)
fatal("ssh_keysign: dup2: %s", strerror(errno));
Sensitive *sensitive = authctxt->sensitive;
Buffer b;
u_char *signature, *blob;
- char *chost, *pkalg, *p;
+ char *chost, *pkalg, *p, myname[NI_MAXHOST];
const char *service;
u_int blen, slen;
int ok, i, len, found = 0;
return 0;
}
/* figure out a name for the client host */
- p = get_local_name(packet_get_connection_in());
+ p = NULL;
+ if (packet_connection_is_on_socket())
+ p = get_local_name(packet_get_connection_in());
+ if (p == NULL) {
+ if (gethostname(myname, sizeof(myname)) == -1) {
+ verbose("userauth_hostbased: gethostname: %s",
+ strerror(errno));
+ } else
+ p = xstrdup(myname);
+ }
if (p == NULL) {
error("userauth_hostbased: cannot get local ipaddr/name");
key_free(private);
+ xfree(blob);
return 0;
}
len = strlen(p) + 2;
- chost = xmalloc(len);
- strlcpy(chost, p, len);
- strlcat(chost, ".", len);
+ xasprintf(&chost, "%s.", p);
debug2("userauth_hostbased: chost %s", chost);
xfree(p);
error("key_sign failed");
xfree(chost);
xfree(pkalg);
+ xfree(blob);
return 0;
}
packet_start(SSH2_MSG_USERAUTH_REQUEST);
xfree(signature);
xfree(chost);
xfree(pkalg);
+ xfree(blob);
packet_send();
return 1;
andersk / gssapi-openssh.git / blobdiff