+/* $OpenBSD: gss-genr.c,v 1.20 2009/06/22 05:39:28 dtucker Exp $ */
+
/*
- * Copyright (c) 2001,2002 Simon Wilkinson. All rights reserved. *
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
#ifdef GSSAPI
-#include "ssh.h"
-#include "ssh2.h"
+#include <sys/types.h>
+#include <sys/param.h>
+
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
#include "xmalloc.h"
#include "buffer.h"
-#include "bufaux.h"
-#include "packet.h"
-#include "compat.h"
-#include <openssl/evp.h>
-#include "cipher.h"
-#include "kex.h"
#include "log.h"
-#include "compat.h"
-#include "monitor_wrap.h"
#include "canohost.h"
-
-#include <netdb.h>
+#include "ssh2.h"
+#include "cipher.h"
+#include "key.h"
+#include "kex.h"
+#include <openssl/evp.h>
#include "ssh-gss.h"
-/* Assorted globals for tracking the clients identity once they've
- * authenticated */
-
-gss_buffer_desc gssapi_client_name = {0,NULL}; /* Name of our client */
-gss_cred_id_t gssapi_client_creds = GSS_C_NO_CREDENTIAL; /* Their credentials */
-enum ssh_gss_id gssapi_client_type = GSS_LAST_ENTRY;
+extern u_char *session_id2;
+extern u_int session_id2_len;
-unsigned char ssh1_key_digest[16]; /* used for ssh1 gssapi */
+typedef struct {
+ char *encoded;
+ gss_OID oid;
+} ssh_gss_kex_mapping;
-/* The mechanism name used in the list below is defined in the internet
- * draft as the Base 64 encoding of the MD5 hash of the ASN.1 DER encoding
- * of the underlying GSSAPI mechanism's OID.
- *
- * Also from the draft, before considering adding SPNEGO, bear in mind that
- * "mechanisms ... MUST NOT use SPNEGO as the underlying GSSAPI mechanism"
+/*
+ * XXX - It would be nice to find a more elegant way of handling the
+ * XXX passing of the key exchange context to the userauth routines
*/
-/* These must be in the same order as ssh_gss_id, in ssh-gss.h */
+Gssctxt *gss_kex_context = NULL;
-ssh_gssapi_mech supported_mechs[]= {
-#ifdef KRB5
- /* Official OID - 1.2.850.113554.1.2.2 */
- {"Se3H81ismmOC3OE+FwYCiQ==","Kerberos",
- {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}},
-#endif
-#ifdef GSI
- /* gssapi_ssleay 1.3.6.1.4.1.3536.1.1 */
- {"N3+k7/4wGxHyuP8Yxi4RhA==",
- "GSI",
- {9, "\x2B\x06\x01\x04\x01\x9B\x50\x01\x01"}
- },
-#endif /* GSI */
- {NULL,NULL,{0,0}}
-};
-
-char gssprefix[]=KEX_GSS_SHA1;
-
-/* Return a list of the gss-group1-sha1-x mechanisms supported by this
- * program.
- *
- * We only support the mechanisms that we've indicated in the list above,
- * but we check that they're supported by the GSSAPI mechanism on the
- * machine. We also check, before including them in the list, that
- * we have the necesary information in order to carry out the key exchange
- * (that is, that the user has credentials, the server's creds are accessible,
- * etc)
+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
+
+int
+ssh_gssapi_oid_table_ok() {
+ return (gss_enc2oid != NULL);
+}
+
+/*
+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
*
- * The way that this is done is fairly nasty, as we do a lot of work that
- * is then thrown away. This should possibly be implemented with a cache
- * that stores the results (in an expanded Gssctxt structure), which are
- * then used by the first calls if that key exchange mechanism is chosen.
+ * We test mechanisms to ensure that we can use them, to avoid starting
+ * a key exchange with a bad mechanism
*/
-
-char *
-ssh_gssapi_mechanisms(int server,char *host) {
- gss_OID_set supported;
- OM_uint32 maj_status, min_status;
- Buffer buf;
- int i = 0;
- int present;
- int mech_count=0;
- char * mechs;
- Gssctxt * ctx = NULL;
-
- if (datafellows & SSH_OLD_GSSAPI) return NULL;
-
- gss_indicate_mechs(&min_status, &supported);
-
- buffer_init(&buf);
- do {
- if ((maj_status=gss_test_oid_set_member(&min_status,
- &supported_mechs[i].oid,
- supported,
- &present))) {
- present=0;
- }
- if (present) {
- if ((server &&
- !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx,
- &supported_mechs[i].oid))))
- || (!server &&
- !GSS_ERROR(ssh_gssapi_client_ctx(&ctx,
- &supported_mechs[i].oid,
- host)))) {
- /* Append gss_group1_sha1_x to our list */
- if (++mech_count > 1) {
- buffer_append(&buf, ",", 1);
- }
- buffer_append(&buf, gssprefix,
- strlen(gssprefix));
- buffer_append(&buf,
- supported_mechs[i].enc_name,
- strlen(supported_mechs[i].enc_name));
- debug("GSSAPI mechanism %s (%s%s) supported",
- supported_mechs[i].name, gssprefix,
- supported_mechs[i].enc_name);
- } else {
- debug("no credentials for GSSAPI mechanism %s",
- supported_mechs[i].name);
- }
- } else {
- debug("GSSAPI mechanism %s not supported",
- supported_mechs[i].name);
- }
- } while (supported_mechs[++i].name != NULL);
-
- buffer_put_char(&buf,'\0');
-
- mechs=xmalloc(buffer_len(&buf));
- buffer_get(&buf,mechs,buffer_len(&buf));
- buffer_free(&buf);
- if (strlen(mechs)==0)
- return(NULL);
- else
- return(mechs);
+char *
+ssh_gssapi_client_mechanisms(const char *host, const char *client) {
+ gss_OID_set gss_supported;
+ OM_uint32 min_status;
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
+ return NULL;
+
+ return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
+ host, client));
}
-void ssh_gssapi_supported_oids(gss_OID_set *oidset) {
- enum ssh_gss_id i =0;
- OM_uint32 maj_status,min_status;
- int present;
- gss_OID_set supported;
-
- gss_create_empty_oid_set(&min_status,oidset);
- gss_indicate_mechs(&min_status, &supported);
-
- while (supported_mechs[i].name!=NULL) {
- if ((maj_status=gss_test_oid_set_member(&min_status,
- &supported_mechs[i].oid,
- supported,
- &present))) {
- present=0;
- }
- if (present) {
- gss_add_oid_set_member(&min_status,
- &supported_mechs[i].oid,
- oidset);
+char *
+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
+ const char *host, const char *client) {
+ Buffer buf;
+ size_t i;
+ int oidpos, enclen;
+ char *mechs, *encoded;
+ u_char digest[EVP_MAX_MD_SIZE];
+ char deroid[2];
+ const EVP_MD *evp_md = EVP_md5();
+ EVP_MD_CTX md;
+
+ if (gss_enc2oid != NULL) {
+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
+ xfree(gss_enc2oid[i].encoded);
+ xfree(gss_enc2oid);
+ }
+
+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
+ (gss_supported->count + 1));
+
+ buffer_init(&buf);
+
+ oidpos = 0;
+ for (i = 0; i < gss_supported->count; i++) {
+ if (gss_supported->elements[i].length < 128 &&
+ (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
+
+ deroid[0] = SSH_GSS_OIDTYPE;
+ deroid[1] = gss_supported->elements[i].length;
+
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, deroid, 2);
+ EVP_DigestUpdate(&md,
+ gss_supported->elements[i].elements,
+ gss_supported->elements[i].length);
+ EVP_DigestFinal(&md, digest, NULL);
+
+ encoded = xmalloc(EVP_MD_size(evp_md) * 2);
+ enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
+ encoded, EVP_MD_size(evp_md) * 2);
+
+ if (oidpos != 0)
+ buffer_put_char(&buf, ',');
+
+ buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID,
+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+
+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
+ gss_enc2oid[oidpos].encoded = encoded;
+ oidpos++;
}
- i++;
}
-}
+ gss_enc2oid[oidpos].oid = NULL;
+ gss_enc2oid[oidpos].encoded = NULL;
-/* Set the contexts OID from a data stream */
-void ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len) {
- if (ctx->oid != GSS_C_NO_OID) {
- xfree(ctx->oid->elements);
- xfree(ctx->oid);
- }
- ctx->oid=xmalloc(sizeof(gss_OID_desc));
- ctx->oid->length=len;
- ctx->oid->elements=xmalloc(len);
- memcpy(ctx->oid->elements,data,len);
-}
+ buffer_put_char(&buf, '\0');
-/* Set the contexts OID */
-void ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid) {
- ssh_gssapi_set_oid_data(ctx,oid->elements,oid->length);
+ mechs = xmalloc(buffer_len(&buf));
+ buffer_get(&buf, mechs, buffer_len(&buf));
+ buffer_free(&buf);
+
+ if (strlen(mechs) == 0) {
+ xfree(mechs);
+ mechs = NULL;
+ }
+
+ return (mechs);
}
-/* Find out which GSS type (out of the list we define in ssh-gss.h) a
- * particular connection is using
- */
-enum ssh_gss_id ssh_gssapi_get_ctype(Gssctxt *ctxt) {
- enum ssh_gss_id i=0;
+gss_OID
+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
+ int i = 0;
- while(supported_mechs[i].name!=NULL) {
- if (supported_mechs[i].oid.length == ctxt->oid->length &&
- (memcmp(supported_mechs[i].oid.elements,
- ctxt->oid->elements,ctxt->oid->length) == 0))
- return i;
- i++;
+ switch (kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GRP14_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GEX_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
+ break;
+ default:
+ return GSS_C_NO_OID;
}
- return(GSS_LAST_ENTRY);
-}
-/* Set the GSS context's OID to the oid indicated by the given key exchange
- * name. */
-gss_OID ssh_gssapi_id_kex(Gssctxt *ctx, char *name) {
- enum ssh_gss_id i=0;
-
- if (strncmp(name, gssprefix, strlen(gssprefix)-1) !=0) {
- return(NULL);
- }
-
- name+=strlen(gssprefix); /* Move to the start of the MIME string */
-
- while (supported_mechs[i].name!=NULL &&
- strcmp(name,supported_mechs[i].enc_name)!=0) {
- i++;
- }
-
- if (supported_mechs[i].name==NULL)
- return (NULL);
-
- if (ctx) ssh_gssapi_set_oid(ctx,&supported_mechs[i].oid);
-
- debug("using GSSAPI mechanism %s (%s%s)", supported_mechs[i].name,
- gssprefix, supported_mechs[i].enc_name);
-
- return &supported_mechs[i].oid;
+ while (gss_enc2oid[i].encoded != NULL &&
+ strcmp(name, gss_enc2oid[i].encoded) != 0)
+ i++;
+
+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
+
+ return gss_enc2oid[i].oid;
}
+/* Check that the OID in a data stream matches that in the context */
+int
+ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
+{
+ return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
+ ctx->oid->length == len &&
+ memcmp(ctx->oid->elements, data, len) == 0);
+}
-/* All this effort to report an error ... */
-static void
-ssh_gssapi_error_ex(OM_uint32 major_status,OM_uint32 minor_status,
- int send_packet) {
- OM_uint32 lmaj, lmin;
- gss_buffer_desc msg = {0,NULL};
- OM_uint32 ctx;
-
- ctx = 0;
- /* The GSSAPI error */
- do {
- lmaj = gss_display_status(&lmin, major_status,
- GSS_C_GSS_CODE,
- GSS_C_NULL_OID,
- &ctx, &msg);
- if (lmaj == GSS_S_COMPLETE) {
- debug((char *)msg.value);
- if (send_packet) packet_send_debug((char *)msg.value);
- (void) gss_release_buffer(&lmin, &msg);
- }
- } while (ctx!=0);
-
- /* The mechanism specific error */
- do {
- lmaj = gss_display_status(&lmin, minor_status,
- GSS_C_MECH_CODE,
- GSS_C_NULL_OID,
- &ctx, &msg);
- if (lmaj == GSS_S_COMPLETE) {
- debug((char *)msg.value);
- if (send_packet) packet_send_debug((char *)msg.value);
- (void) gss_release_buffer(&lmin, &msg);
- }
- } while (ctx!=0);
+/* Set the contexts OID from a data stream */
+void
+ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
+{
+ if (ctx->oid != GSS_C_NO_OID) {
+ xfree(ctx->oid->elements);
+ xfree(ctx->oid);
+ }
+ ctx->oid = xmalloc(sizeof(gss_OID_desc));
+ ctx->oid->length = len;
+ ctx->oid->elements = xmalloc(len);
+ memcpy(ctx->oid->elements, data, len);
}
+/* Set the contexts OID */
void
-ssh_gssapi_error(OM_uint32 major_status,OM_uint32 minor_status) {
- ssh_gssapi_error_ex(major_status, minor_status, 0);
+ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
+{
+ ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
}
+/* All this effort to report an error ... */
void
-ssh_gssapi_send_error(OM_uint32 major_status,OM_uint32 minor_status) {
- ssh_gssapi_error_ex(major_status, minor_status, 1);
+ssh_gssapi_error(Gssctxt *ctxt)
+{
+ char *s;
+
+ s = ssh_gssapi_last_error(ctxt, NULL, NULL);
+ debug("%s", s);
+ xfree(s);
}
+char *
+ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
+ OM_uint32 *minor_status)
+{
+ OM_uint32 lmin;
+ gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
+ OM_uint32 ctx;
+ Buffer b;
+ char *ret;
+
+ buffer_init(&b);
+
+ if (major_status != NULL)
+ *major_status = ctxt->major;
+ if (minor_status != NULL)
+ *minor_status = ctxt->minor;
+
+ ctx = 0;
+ /* The GSSAPI error */
+ do {
+ gss_display_status(&lmin, ctxt->major,
+ GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg);
+ buffer_append(&b, msg.value, msg.length);
+ buffer_put_char(&b, '\n');
+ gss_release_buffer(&lmin, &msg);
+ } while (ctx != 0);
-/* Initialise our GSSAPI context. We use this opaque structure to contain all
+ /* The mechanism specific error */
+ do {
+ gss_display_status(&lmin, ctxt->minor,
+ GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg);
+
+ buffer_append(&b, msg.value, msg.length);
+ buffer_put_char(&b, '\n');
+
+ gss_release_buffer(&lmin, &msg);
+ } while (ctx != 0);
+
+ buffer_put_char(&b, '\0');
+ ret = xmalloc(buffer_len(&b));
+ buffer_get(&b, ret, buffer_len(&b));
+ buffer_free(&b);
+ return (ret);
+}
+
+/*
+ * Initialise our GSSAPI context. We use this opaque structure to contain all
* of the data which both the client and server need to persist across
* {accept,init}_sec_context calls, so that when we do it from the userauth
* stuff life is a little easier
void
ssh_gssapi_build_ctx(Gssctxt **ctx)
{
- *ctx=xmalloc(sizeof (Gssctxt));
- (*ctx)->context=GSS_C_NO_CONTEXT;
- (*ctx)->name=GSS_C_NO_NAME;
- (*ctx)->oid=GSS_C_NO_OID;
- (*ctx)->creds=GSS_C_NO_CREDENTIAL;
- (*ctx)->client=GSS_C_NO_NAME;
- (*ctx)->client_creds=GSS_C_NO_CREDENTIAL;
+ *ctx = xcalloc(1, sizeof (Gssctxt));
+ (*ctx)->context = GSS_C_NO_CONTEXT;
+ (*ctx)->name = GSS_C_NO_NAME;
+ (*ctx)->oid = GSS_C_NO_OID;
+ (*ctx)->creds = GSS_C_NO_CREDENTIAL;
+ (*ctx)->client = GSS_C_NO_NAME;
+ (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
}
/* Delete our context, providing it has been built correctly */
void
ssh_gssapi_delete_ctx(Gssctxt **ctx)
{
+#if !defined(MECHGLUE)
OM_uint32 ms;
-
- /* Return if there's no context */
- if ((*ctx)==NULL)
+#endif
+
+ if ((*ctx) == NULL)
return;
-
#if !defined(MECHGLUE) /* mechglue has some memory management issues */
- if ((*ctx)->context != GSS_C_NO_CONTEXT)
- gss_delete_sec_context(&ms,&(*ctx)->context,GSS_C_NO_BUFFER);
+ if ((*ctx)->context != GSS_C_NO_CONTEXT)
+ gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
if ((*ctx)->name != GSS_C_NO_NAME)
- gss_release_name(&ms,&(*ctx)->name);
+ gss_release_name(&ms, &(*ctx)->name);
if ((*ctx)->oid != GSS_C_NO_OID) {
xfree((*ctx)->oid->elements);
xfree((*ctx)->oid);
(*ctx)->oid = GSS_C_NO_OID;
}
if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
- gss_release_cred(&ms,&(*ctx)->creds);
+ gss_release_cred(&ms, &(*ctx)->creds);
if ((*ctx)->client != GSS_C_NO_NAME)
- gss_release_name(&ms,&(*ctx)->client);
+ gss_release_name(&ms, &(*ctx)->client);
if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
- gss_release_cred(&ms,&(*ctx)->client_creds);
+ gss_release_cred(&ms, &(*ctx)->client_creds);
#endif
-
+
xfree(*ctx);
- *ctx=NULL;
+ *ctx = NULL;
}
-/* Wrapper to init_sec_context
+/*
+ * Wrapper to init_sec_context
* Requires that the context contains:
* oid
- * server name (from ssh_gssapi_import_name)
+ * server name (from ssh_gssapi_import_name)
*/
-OM_uint32
+OM_uint32
ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
- gss_buffer_desc* send_tok, OM_uint32 *flags)
+ gss_buffer_desc* send_tok, OM_uint32 *flags)
{
- OM_uint32 maj_status, min_status;
int deleg_flag = 0;
-
+
if (deleg_creds) {
- deleg_flag=GSS_C_DELEG_FLAG;
+ deleg_flag = GSS_C_DELEG_FLAG;
debug("Delegating credentials");
}
-
- maj_status=gss_init_sec_context(&min_status,
- GSS_C_NO_CREDENTIAL, /* def. cred */
- &ctx->context,
- ctx->name,
- ctx->oid,
- GSS_C_MUTUAL_FLAG |
- GSS_C_INTEG_FLAG |
- deleg_flag,
- 0, /* default lifetime */
- NULL, /* no channel bindings */
- recv_tok,
- NULL,
- send_tok,
- flags,
- NULL);
- ctx->status=maj_status;
- if (GSS_ERROR(maj_status)) {
- ssh_gssapi_error(maj_status,min_status);
- }
- return(maj_status);
-}
-/* Wrapper arround accept_sec_context
- * Requires that the context contains:
- * oid
- * credentials (from ssh_gssapi_acquire_cred)
- */
-OM_uint32 ssh_gssapi_accept_ctx(Gssctxt *ctx,gss_buffer_desc *recv_tok,
- gss_buffer_desc *send_tok, OM_uint32 *flags)
-{
- OM_uint32 maj_status, min_status;
- gss_OID mech;
-
- maj_status=gss_accept_sec_context(&min_status,
- &ctx->context,
- ctx->creds,
- recv_tok,
- GSS_C_NO_CHANNEL_BINDINGS,
- &ctx->client,
- &mech,
- send_tok,
- flags,
- NULL,
- &ctx->client_creds);
- if (GSS_ERROR(maj_status)) {
- ssh_gssapi_send_error(maj_status,min_status);
- }
-
- if (ctx->client_creds) {
- debug("Received some client credentials");
- } else {
- debug("Got no client credentials");
- }
+ ctx->major = gss_init_sec_context(&ctx->minor,
+ ctx->client_creds, &ctx->context, ctx->name, ctx->oid,
+ GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
+ 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
- /* FIXME: We should check that the me
- * the one that we asked for (in ctx->oid) */
-
- ctx->status=maj_status;
-
- /* Now, if we're complete and we have the right flags, then
- * we flag the user as also having been authenticated
- */
-
- if (((flags==NULL) || ((*flags & GSS_C_MUTUAL_FLAG) &&
- (*flags & GSS_C_INTEG_FLAG))) &&
- (maj_status == GSS_S_COMPLETE)) {
- if (ssh_gssapi_getclient(ctx,&gssapi_client_type,
- &gssapi_client_name,
- &gssapi_client_creds))
- fatal("Couldn't convert client name");
- }
+ if (GSS_ERROR(ctx->major))
+ ssh_gssapi_error(ctx);
- return(maj_status);
+ return (ctx->major);
}
/* Create a service name for the given host */
OM_uint32
-ssh_gssapi_import_name(Gssctxt *ctx, const char *host) {
- gss_buffer_desc gssbuf = {0,NULL};
- OM_uint32 maj_status, min_status;
+ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
+{
+ gss_buffer_desc gssbuf;
char *xhost;
-
+ char *val;
+
/* Make a copy of the host name, in case it was returned by a
* previous call to gethostbyname(). */
xhost = xstrdup(host);
- /* If xhost is the loopback interface, switch it to our
- true local hostname. */
- resolve_localhost(&xhost);
-
- /* Make sure we have the FQHN. Some GSSAPI implementations don't do
+ /* Make sure we have the FQDN. Some GSSAPI implementations don't do
* this for us themselves */
- make_fqhn(&xhost);
-
- gssbuf.length = sizeof("host@")+strlen(xhost);
-
- gssbuf.value = xmalloc(gssbuf.length);
- if (gssbuf.value == NULL) {
- xfree(xhost);
- return(-1);
- }
- snprintf(gssbuf.value,gssbuf.length,"host@%s",xhost);
- if ((maj_status=gss_import_name(&min_status,
- &gssbuf,
- GSS_C_NT_HOSTBASED_SERVICE,
- &ctx->name))) {
- ssh_gssapi_error(maj_status,min_status);
- }
+ resolve_localhost(&xhost);
+ xasprintf(&val, "host@%s", xhost);
+ gssbuf.value = val;
+ gssbuf.length = strlen(gssbuf.value);
+
+ if ((ctx->major = gss_import_name(&ctx->minor,
+ &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
+ ssh_gssapi_error(ctx);
+
xfree(xhost);
xfree(gssbuf.value);
- return(maj_status);
+ return (ctx->major);
}
-/* Acquire credentials for a server running on the current host.
- * Requires that the context structure contains a valid OID
- */
-
-/* Returns a GSSAPI error code */
OM_uint32
-ssh_gssapi_acquire_cred(Gssctxt *ctx) {
- OM_uint32 maj_status, min_status;
- char lname[MAXHOSTNAMELEN];
+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
+{
+ gss_buffer_desc gssbuf;
+ gss_name_t gssname;
+ OM_uint32 status;
gss_OID_set oidset;
-
- gss_create_empty_oid_set(&min_status,&oidset);
- gss_add_oid_set_member(&min_status,ctx->oid,&oidset);
-
- if (gethostname(lname, MAXHOSTNAMELEN)) {
- return(-1);
- }
- if ((maj_status=ssh_gssapi_import_name(ctx,lname))) {
- return(maj_status);
- }
- if ((maj_status=gss_acquire_cred(&min_status,
- ctx->name,
- 0,
- oidset,
- GSS_C_ACCEPT,
- &ctx->creds,
- NULL,
- NULL))) {
- ssh_gssapi_error(maj_status,min_status);
- }
-
- gss_release_oid_set(&min_status, &oidset);
- return(maj_status);
-}
+ gssbuf.value = (void *) name;
+ gssbuf.length = strlen(gssbuf.value);
-/* Extract the client details from a given context. This can only reliably
- * be called once for a context */
+ gss_create_empty_oid_set(&status, &oidset);
+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
-OM_uint32
-ssh_gssapi_getclient(Gssctxt *ctx, enum ssh_gss_id *type,
- gss_buffer_desc *name, gss_cred_id_t *creds) {
+ ctx->major = gss_import_name(&ctx->minor, &gssbuf,
+ GSS_C_NT_USER_NAME, &gssname);
- OM_uint32 maj_status,min_status;
-
- *type=ssh_gssapi_get_ctype(ctx);
- if ((maj_status=gss_display_name(&min_status,ctx->client,name,NULL))) {
- ssh_gssapi_error(maj_status,min_status);
- }
-
- /* This is icky. There appears to be no way to copy this structure,
- * rather than the pointer to it, so we simply copy the pointer and
- * mark the originator as empty so we don't destroy it.
- */
- *creds=ctx->client_creds;
- ctx->client_creds=GSS_C_NO_CREDENTIAL;
- return(maj_status);
+ if (!ctx->major)
+ ctx->major = gss_acquire_cred(&ctx->minor,
+ gssname, 0, oidset, GSS_C_INITIATE,
+ &ctx->client_creds, NULL, NULL);
+
+ gss_release_name(&status, &gssname);
+ gss_release_oid_set(&status, &oidset);
+
+ if (ctx->major)
+ ssh_gssapi_error(ctx);
+
+ return(ctx->major);
}
OM_uint32
-ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *buffer, gss_buffer_desc *hash) {
- OM_uint32 maj_status,min_status;
-
- /* ssh1 needs to exchange the hash of the keys */
- /* will us this hash to return it */
- if (!compat20) {
- if ((maj_status=gss_wrap(&min_status,ctx->context,
- 0,
- GSS_C_QOP_DEFAULT,
- buffer,
- NULL,
- hash)))
- ssh_gssapi_error(maj_status,min_status);
- }
- else
+ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
+{
+ if (ctx == NULL)
+ return -1;
- if ((maj_status=gss_get_mic(&min_status,ctx->context,
- GSS_C_QOP_DEFAULT, buffer, hash))) {
- ssh_gssapi_error(maj_status,min_status);
- }
-
- return(maj_status);
+ if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
+ GSS_C_QOP_DEFAULT, buffer, hash)))
+ ssh_gssapi_error(ctx);
+
+ return (ctx->major);
}
+/* Priviledged when used by server */
OM_uint32
-ssh_gssapi_server_ctx(Gssctxt **ctx,gss_OID oid) {
- if (*ctx) ssh_gssapi_delete_ctx(ctx);
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+ if (ctx == NULL)
+ return -1;
+
+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+ gssbuf, gssmic, NULL);
+
+ return (ctx->major);
+}
+
+void
+ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
+ const char *context)
+{
+ buffer_init(b);
+ buffer_put_string(b, session_id2, session_id2_len);
+ buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
+ buffer_put_cstring(b, user);
+ buffer_put_cstring(b, service);
+ buffer_put_cstring(b, context);
+}
+
+int
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host,
+ const char *client)
+{
+ gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+ Gssctxt *intctx = NULL;
+
+ if (ctx == NULL)
+ ctx = &intctx;
+
+ /* RFC 4462 says we MUST NOT do SPNEGO */
+ if (oid->length == spnego_oid.length &&
+ (memcmp(oid->elements, spnego_oid.elements, oid->length) == 0))
+ return 0; /* false */
+
ssh_gssapi_build_ctx(ctx);
- ssh_gssapi_set_oid(*ctx,oid);
- return(ssh_gssapi_acquire_cred(*ctx));
+ ssh_gssapi_set_oid(*ctx, oid);
+ major = ssh_gssapi_import_name(*ctx, host);
+
+ if (!GSS_ERROR(major) && client)
+ major = ssh_gssapi_client_identity(*ctx, client);
+
+ if (!GSS_ERROR(major)) {
+ major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
+ NULL);
+ gss_release_buffer(&minor, &token);
+ if ((*ctx)->context != GSS_C_NO_CONTEXT)
+ gss_delete_sec_context(&minor, &(*ctx)->context,
+ GSS_C_NO_BUFFER);
+ }
+
+ if (GSS_ERROR(major) || intctx != NULL)
+ ssh_gssapi_delete_ctx(ctx);
+
+ return (!GSS_ERROR(major));
}
-OM_uint32
-ssh_gssapi_client_ctx(Gssctxt **ctx,gss_OID oid, char *host) {
- gss_buffer_desc token = {0,NULL};
- OM_uint32 major,minor;
+int
+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
+ static gss_name_t saved_name = GSS_C_NO_NAME;
+ static OM_uint32 saved_lifetime = 0;
+ static gss_OID saved_mech = GSS_C_NO_OID;
+ static gss_name_t name;
+ static OM_uint32 last_call = 0;
+ OM_uint32 lifetime, now, major, minor;
+ int equal;
- if (*ctx) ssh_gssapi_delete_ctx(ctx);
- ssh_gssapi_build_ctx(ctx);
- ssh_gssapi_set_oid(*ctx,oid);
- ssh_gssapi_import_name(*ctx,host);
- major=ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token, NULL);
- gss_release_buffer(&minor,&token);
- return(major);
+ now = time(NULL);
+
+ if (ctxt) {
+ debug("Rekey has happened - updating saved versions");
+
+ if (saved_name != GSS_C_NO_NAME)
+ gss_release_name(&minor, &saved_name);
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &saved_name, &saved_lifetime, NULL, NULL);
+
+ if (!GSS_ERROR(major)) {
+ saved_mech = ctxt->oid;
+ saved_lifetime+= now;
+ } else {
+ /* Handle the error */
+ }
+ return 0;
+ }
+
+ if (now - last_call < 10)
+ return 0;
+
+ last_call = now;
+
+ if (saved_mech == GSS_C_NO_OID)
+ return 0;
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &name, &lifetime, NULL, NULL);
+ if (major == GSS_S_CREDENTIALS_EXPIRED)
+ return 0;
+ else if (GSS_ERROR(major))
+ return 0;
+
+ major = gss_compare_name(&minor, saved_name, name, &equal);
+ gss_release_name(&minor, &name);
+ if (GSS_ERROR(major))
+ return 0;
+
+ if (equal && (saved_lifetime < lifetime + now - 10))
+ return 1;
+
+ return 0;
}
-
+
#endif /* GSSAPI */
andersk / gssapi-openssh.git / blobdiff