]> andersk Git - gssapi-openssh.git/blobdiff - openssh/sshconnect2.c
merged OpenSSH 5.1p1 to trunk
[gssapi-openssh.git] / openssh / sshconnect2.c
index 0485095ae901bf9d1844b962f83ea2e37779993d..faa1d9455f77c96f2a72e16a37554e7fbe9ec36f 100644 (file)
@@ -1,3 +1,4 @@
+/* $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 1.143 2005/10/14 02:17:59 stevesk 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"
@@ -49,6 +66,7 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.143 2005/10/14 02:17:59 stevesk Exp $");
 #include "canohost.h"
 #include "msg.h"
 #include "pathnames.h"
+#include "uidswap.h"
 
 #ifdef GSSAPI
 #include "ssh-gss.h"
@@ -58,7 +76,6 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.143 2005/10/14 02:17:59 stevesk Exp $");
 extern char *client_version_string;
 extern char *server_version_string;
 extern Options options;
-extern Kex *xxx_kex;
 
 /* tty_flag is set in ssh.c. use this in ssh_userauth2 */
 /* if it is set then prevent the switch to the null cipher */
@@ -92,8 +109,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 
 #ifdef GSSAPI
        char *orig = NULL, *gss = NULL;
-       int len;
-        char *gss_host = NULL;
+       char *gss_host = NULL;
 #endif
 
        xxx_host = host;
@@ -101,22 +117,21 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 
 #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];
-       if (options.gss_trust_dns)
-               gss_host = (char *)get_canonical_hostname(1);
-       else
-               gss_host = host;
+               /* 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(gss_host);
-       if (gss) {
-               debug("Offering GSSAPI proposal: %s", gss);
-               len = strlen(orig) + strlen(gss) + 2;
-               myproposal[PROPOSAL_KEX_ALGS] = xmalloc(len);
-               snprintf(myproposal[PROPOSAL_KEX_ALGS], len, "%s,%s", gss, 
-                   orig);
-       }
+               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
 
@@ -152,23 +167,23 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
         * '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, 
+               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;
@@ -380,14 +395,28 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
 
        pubkey_cleanup(&authctxt);
        dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
-       if ((options.none_switch == 1) && !tty_flag) /* no null on tty sessions */
+
+       /* 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)) 
        {
-               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 NULL CIPHER\n");
+               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);
 }
@@ -437,14 +466,21 @@ input_userauth_error(int type, u_int32_t seq, void *ctxt)
 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);
 }
 
@@ -584,17 +620,10 @@ userauth_gssapi(Authctxt *authctxt)
 
        /* 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 &&
-                   ssh_gssapi_check_mechanism(&gss_supported->elements[mech],
-                                              gss_host) &&
-                   !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
-                                                     gss_host))) {
+                   ssh_gssapi_check_mechanism(&gssctxt, 
+                   &gss_supported->elements[mech], gss_host)) {
                        ok = 1; /* Mechanism works */
                } else {
                        mech++;
@@ -691,8 +720,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
 {
        Authctxt *authctxt = ctxt;
        Gssctxt *gssctxt;
-       unsigned int oidlen;
-       unsigned char *oidv;
+       u_int oidlen;
+       u_char *oidv;
 
        if (authctxt == NULL)
                fatal("input_gssapi_response: no authentication context");
@@ -1156,14 +1185,16 @@ load_identity_file(char *filename)
 {
        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;
@@ -1172,8 +1203,8 @@ load_identity_file(char *filename)
                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");
@@ -1216,8 +1247,7 @@ pubkey_prepare(Authctxt *authctxt)
                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);
@@ -1241,8 +1271,7 @@ pubkey_prepare(Authctxt *authctxt)
                                }
                        }
                        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;
@@ -1438,8 +1467,7 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
                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));
@@ -1491,7 +1519,7 @@ userauth_hostbased(Authctxt *authctxt)
        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;
@@ -1515,16 +1543,24 @@ userauth_hostbased(Authctxt *authctxt)
                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);
 
@@ -1557,6 +1593,7 @@ userauth_hostbased(Authctxt *authctxt)
                error("key_sign failed");
                xfree(chost);
                xfree(pkalg);
+               xfree(blob);
                return 0;
        }
        packet_start(SSH2_MSG_USERAUTH_REQUEST);
@@ -1572,6 +1609,7 @@ userauth_hostbased(Authctxt *authctxt)
        xfree(signature);
        xfree(chost);
        xfree(pkalg);
+       xfree(blob);
 
        packet_send();
        return 1;
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