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-rw-r--r--utils/gssd/context_lucid.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/utils/gssd/context_lucid.c b/utils/gssd/context_lucid.c
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+++ b/utils/gssd/context_lucid.c
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+/*
+ * COPYRIGHT (c) 2006
+ * The Regents of the University of Michigan
+ * ALL RIGHTS RESERVED
+ *
+ * Permission is granted to use, copy, create derivative works
+ * and redistribute this software and such derivative works
+ * for any purpose, so long as the name of The University of
+ * Michigan is not used in any advertising or publicity
+ * pertaining to the use of distribution of this software
+ * without specific, written prior authorization. If the
+ * above copyright notice or any other identification of the
+ * University of Michigan is included in any copy of any
+ * portion of this software, then the disclaimer below must
+ * also be included.
+ *
+ * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
+ * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
+ * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
+ * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
+ * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
+ * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
+ * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGES.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#ifdef HAVE_LUCID_CONTEXT_SUPPORT
+
+/*
+ * Newer versions of MIT and Heimdal have lucid context support.
+ * We can use common code if it is supported.
+ */
+
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+#include <errno.h>
+
+#include <gssapi/gssapi_krb5.h>
+
+#include "gss_util.h"
+#include "gss_oids.h"
+#include "err_util.h"
+#include "context.h"
+
+#ifndef OM_uint64
+typedef uint64_t OM_uint64;
+#endif
+
+static int
+write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
+{
+ gss_buffer_desc tmp;
+
+ if (WRITE_BYTES(p, end, key->type)) return -1;
+ tmp.length = key->length;
+ tmp.value = key->data;
+ if (write_buffer(p, end, &tmp)) return -1;
+ return 0;
+}
+
+static int
+prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
+ gss_buffer_desc *buf, int32_t *endtime)
+{
+#define FAKESEED_SIZE 16
+ char *p, *end;
+ static int constant_zero = 0;
+ unsigned char fakeseed[FAKESEED_SIZE];
+ uint32_t word_send_seq;
+ gss_krb5_lucid_key_t enc_key;
+ uint32_t i;
+ char *skd, *dkd;
+ gss_buffer_desc fakeoid;
+ int err;
+
+ /*
+ * The new Kerberos interface to get the gss context
+ * does not include the seed or seed_init fields
+ * because we never really use them. But for now,
+ * send down a fake buffer so we can use the same
+ * interface to the kernel.
+ */
+ memset(&enc_key, 0, sizeof(enc_key));
+ memset(&fakeoid, 0, sizeof(fakeoid));
+ memset(fakeseed, 0, FAKESEED_SIZE);
+
+ if (!(buf->value = calloc(1, MAX_CTX_LEN)))
+ goto out_err;
+ p = buf->value;
+ end = buf->value + MAX_CTX_LEN;
+
+ if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
+
+ /* seed_init and seed not used by kernel anyway */
+ if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
+ if (write_bytes(&p, end, &fakeseed, FAKESEED_SIZE)) goto out_err;
+
+ if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
+ if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
+ if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
+ if (endtime)
+ *endtime = lctx->endtime;
+ word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
+ if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
+ if (write_oid(&p, end, &krb5oid)) goto out_err;
+
+#ifdef HAVE_HEIMDAL
+ /*
+ * The kernel gss code expects des-cbc-raw for all flavors of des.
+ * The keytype from MIT has this type, but Heimdal does not.
+ * Force the Heimdal keytype to 4 (des-cbc-raw).
+ * Note that the rfc1964 version only supports DES enctypes.
+ */
+ if (lctx->rfc1964_kd.ctx_key.type != 4) {
+ printerr(2, "%s: overriding heimdal keytype (%d => %d)\n",
+ __FUNCTION__, lctx->rfc1964_kd.ctx_key.type, 4);
+ lctx->rfc1964_kd.ctx_key.type = 4;
+ }
+#endif
+ printerr(2, "%s: serializing keys with enctype %d and length %d\n",
+ __FUNCTION__, lctx->rfc1964_kd.ctx_key.type,
+ lctx->rfc1964_kd.ctx_key.length);
+
+ /* derive the encryption key and copy it into buffer */
+ enc_key.type = lctx->rfc1964_kd.ctx_key.type;
+ enc_key.length = lctx->rfc1964_kd.ctx_key.length;
+ if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
+ goto out_err;
+ skd = (char *) lctx->rfc1964_kd.ctx_key.data;
+ dkd = (char *) enc_key.data;
+ for (i = 0; i < enc_key.length; i++)
+ dkd[i] = skd[i] ^ 0xf0;
+ err = write_lucid_keyblock(&p, end, &enc_key);
+ free(enc_key.data);
+ if (err)
+ goto out_err;
+
+ if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
+ goto out_err;
+
+ buf->length = p - (char *)buf->value;
+ return 0;
+out_err:
+ printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
+ if (buf->value) free(buf->value);
+ buf->length = 0;
+ return -1;
+}
+
+/* Flags for version 2 context flags */
+#define KRB5_CTX_FLAG_INITIATOR 0x00000001
+#define KRB5_CTX_FLAG_CFX 0x00000002
+#define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
+
+/*
+ * Prepare a new-style buffer, as defined in rfc4121 (a.k.a. cfx),
+ * to send to the kernel for newer encryption types -- or for DES3.
+ *
+ * The new format is:
+ *
+ * u32 flags;
+ * #define KRB5_CTX_FLAG_INITIATOR 0x00000001
+ * #define KRB5_CTX_FLAG_CFX 0x00000002
+ * #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
+ * s32 endtime;
+ * u64 seq_send;
+ * u32 enctype; ( encrption type of key )
+ * raw key; ( raw key bytes (kernel will derive))
+ *
+ */
+static int
+prepare_krb5_rfc4121_buffer(gss_krb5_lucid_context_v1_t *lctx,
+ gss_buffer_desc *buf, int32_t *endtime)
+{
+ char *p, *end;
+ uint32_t v2_flags = 0;
+ uint32_t enctype;
+ uint32_t keysize;
+
+ if (!(buf->value = calloc(1, MAX_CTX_LEN)))
+ goto out_err;
+ p = buf->value;
+ end = buf->value + MAX_CTX_LEN;
+
+ /* Version 2 */
+ if (lctx->initiate)
+ v2_flags |= KRB5_CTX_FLAG_INITIATOR;
+ if (lctx->protocol != 0)
+ v2_flags |= KRB5_CTX_FLAG_CFX;
+ if (lctx->protocol != 0 && lctx->cfx_kd.have_acceptor_subkey == 1)
+ v2_flags |= KRB5_CTX_FLAG_ACCEPTOR_SUBKEY;
+
+ if (WRITE_BYTES(&p, end, v2_flags)) goto out_err;
+ if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
+ if (endtime)
+ *endtime = lctx->endtime;
+ if (WRITE_BYTES(&p, end, lctx->send_seq)) goto out_err;
+
+ /* Protocol 0 here implies DES3 or RC4 */
+ printerr(4, "%s: protocol %d\n", __FUNCTION__, lctx->protocol);
+ if (lctx->protocol == 0) {
+ enctype = lctx->rfc1964_kd.ctx_key.type;
+ keysize = lctx->rfc1964_kd.ctx_key.length;
+ } else {
+ if (lctx->cfx_kd.have_acceptor_subkey) {
+ enctype = lctx->cfx_kd.acceptor_subkey.type;
+ keysize = lctx->cfx_kd.acceptor_subkey.length;
+ } else {
+ enctype = lctx->cfx_kd.ctx_key.type;
+ keysize = lctx->cfx_kd.ctx_key.length;
+ }
+ }
+ printerr(4, "%s: serializing key with enctype %d and size %d\n",
+ __FUNCTION__, enctype, keysize);
+
+ if (WRITE_BYTES(&p, end, enctype)) goto out_err;
+
+ if (lctx->protocol == 0) {
+ if (write_bytes(&p, end, lctx->rfc1964_kd.ctx_key.data,
+ lctx->rfc1964_kd.ctx_key.length))
+ goto out_err;
+ } else {
+ if (lctx->cfx_kd.have_acceptor_subkey) {
+ if (write_bytes(&p, end,
+ lctx->cfx_kd.acceptor_subkey.data,
+ lctx->cfx_kd.acceptor_subkey.length))
+ goto out_err;
+ } else {
+ if (write_bytes(&p, end, lctx->cfx_kd.ctx_key.data,
+ lctx->cfx_kd.ctx_key.length))
+ goto out_err;
+ }
+ }
+
+ buf->length = p - (char *)buf->value;
+ return 0;
+
+out_err:
+ printerr(0, "ERROR: %s: failed serializing krb5 context for kernel\n",
+ __FUNCTION__);
+ if (buf->value) {
+ free(buf->value);
+ buf->value = NULL;
+ }
+ buf->length = 0;
+ return -1;
+}
+
+
+int
+serialize_krb5_ctx(gss_ctx_id_t *ctx, gss_buffer_desc *buf, int32_t *endtime)
+{
+ OM_uint32 maj_stat, min_stat;
+ void *return_ctx = 0;
+ OM_uint32 vers;
+ gss_krb5_lucid_context_v1_t *lctx = 0;
+ int retcode = 0;
+
+ printerr(4, "DEBUG: %s: lucid version!\n", __FUNCTION__);
+ maj_stat = gss_export_lucid_sec_context(&min_stat, ctx,
+ 1, &return_ctx);
+ if (maj_stat != GSS_S_COMPLETE) {
+ pgsserr("gss_export_lucid_sec_context",
+ maj_stat, min_stat, &krb5oid);
+ goto out_err;
+ }
+
+ /* Check the version returned, we only support v1 right now */
+ vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
+ switch (vers) {
+ case 1:
+ lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
+ break;
+ default:
+ printerr(0, "ERROR: unsupported lucid sec context version %d\n",
+ vers);
+ goto out_err;
+ break;
+ }
+
+ /*
+ * Now lctx points to a lucid context that we can send down to kernel
+ *
+ * Note: we send down different information to the kernel depending
+ * on the protocol version and the enctyption type.
+ * For protocol version 0 with all enctypes besides DES3, we use
+ * the original format. For protocol version != 0 or DES3, we
+ * send down the new style information.
+ */
+
+ if (lctx->protocol == 0 && lctx->rfc1964_kd.ctx_key.type <= 4)
+ retcode = prepare_krb5_rfc1964_buffer(lctx, buf, endtime);
+ else
+ retcode = prepare_krb5_rfc4121_buffer(lctx, buf, endtime);
+
+ maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
+ if (maj_stat != GSS_S_COMPLETE) {
+ pgsserr("gss_free_lucid_sec_context",
+ maj_stat, min_stat, &krb5oid);
+ printerr(0, "WARN: failed to free lucid sec context\n");
+ }
+
+ if (retcode) {
+ printerr(1, "%s: prepare_krb5_*_buffer failed (retcode = %d)\n",
+ __FUNCTION__, retcode);
+ goto out_err;
+ }
+
+ return 0;
+
+out_err:
+ printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
+ return -1;
+}
+
+
+
+#endif /* HAVE_LUCID_CONTEXT_SUPPORT */