e21866f7a2
Zero out the DES_cblock structure instead of the (not yet used at this point in the function) key schedule. The contents could potentially be left on the stack in the case of an error return from _gssapi_verify_pad().
453 lines
12 KiB
C
453 lines
12 KiB
C
/*
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* Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
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* (Royal Institute of Technology, Stockholm, Sweden).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "gsskrb5_locl.h"
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#ifdef HEIM_WEAK_CRYPTO
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static OM_uint32
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unwrap_des
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(OM_uint32 * minor_status,
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const gsskrb5_ctx context_handle,
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const gss_buffer_t input_message_buffer,
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gss_buffer_t output_message_buffer,
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int * conf_state,
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gss_qop_t * qop_state,
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krb5_keyblock *key
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)
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{
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u_char *p, *seq;
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size_t len;
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EVP_MD_CTX *md5;
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u_char hash[16];
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EVP_CIPHER_CTX des_ctx;
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DES_key_schedule schedule;
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DES_cblock deskey;
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DES_cblock zero;
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size_t i;
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uint32_t seq_number;
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size_t padlength;
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OM_uint32 ret;
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int cstate;
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int cmp;
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int token_len;
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if (IS_DCE_STYLE(context_handle)) {
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token_len = 22 + 8 + 15; /* 45 */
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} else {
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token_len = input_message_buffer->length;
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}
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p = input_message_buffer->value;
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ret = _gsskrb5_verify_header (&p,
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token_len,
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"\x02\x01",
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GSS_KRB5_MECHANISM);
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if (ret)
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return ret;
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if (memcmp (p, "\x00\x00", 2) != 0)
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return GSS_S_BAD_SIG;
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p += 2;
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if (memcmp (p, "\x00\x00", 2) == 0) {
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cstate = 1;
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} else if (memcmp (p, "\xFF\xFF", 2) == 0) {
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cstate = 0;
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} else
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return GSS_S_BAD_MIC;
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p += 2;
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if(conf_state != NULL)
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*conf_state = cstate;
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if (memcmp (p, "\xff\xff", 2) != 0)
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return GSS_S_DEFECTIVE_TOKEN;
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p += 2;
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p += 16;
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len = p - (u_char *)input_message_buffer->value;
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if(cstate) {
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/* decrypt data */
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memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
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memset (&zero, 0, sizeof(zero));
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for (i = 0; i < sizeof(deskey); ++i)
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deskey[i] ^= 0xf0;
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EVP_CIPHER_CTX_init(&des_ctx);
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EVP_CipherInit_ex(&des_ctx, EVP_des_cbc(), NULL, deskey, zero, 0);
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EVP_Cipher(&des_ctx, p, p, input_message_buffer->length - len);
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EVP_CIPHER_CTX_cleanup(&des_ctx);
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memset (&deskey, 0, sizeof(deskey));
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}
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if (IS_DCE_STYLE(context_handle)) {
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padlength = 0;
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} else {
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/* check pad */
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ret = _gssapi_verify_pad(input_message_buffer,
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input_message_buffer->length - len,
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&padlength);
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if (ret)
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return ret;
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}
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md5 = EVP_MD_CTX_create();
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EVP_DigestInit_ex(md5, EVP_md5(), NULL);
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EVP_DigestUpdate(md5, p - 24, 8);
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EVP_DigestUpdate(md5, p, input_message_buffer->length - len);
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EVP_DigestFinal_ex(md5, hash, NULL);
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EVP_MD_CTX_destroy(md5);
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memset (&zero, 0, sizeof(zero));
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memcpy (&deskey, key->keyvalue.data, sizeof(deskey));
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DES_set_key_unchecked (&deskey, &schedule);
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DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash),
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&schedule, &zero);
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if (ct_memcmp (p - 8, hash, 8) != 0) {
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memset_s(&deskey, sizeof(deskey), 0, sizeof(deskey));
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memset_s(&schedule, sizeof(schedule), 0, sizeof(schedule));
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return GSS_S_BAD_MIC;
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}
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/* verify sequence number */
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HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
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p -= 16;
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EVP_CIPHER_CTX_init(&des_ctx);
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EVP_CipherInit_ex(&des_ctx, EVP_des_cbc(), NULL, key->keyvalue.data, hash, 0);
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EVP_Cipher(&des_ctx, p, p, 8);
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EVP_CIPHER_CTX_cleanup(&des_ctx);
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memset (deskey, 0, sizeof(deskey));
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memset (&schedule, 0, sizeof(schedule));
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seq = p;
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_gsskrb5_decode_om_uint32(seq, &seq_number);
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if (context_handle->more_flags & LOCAL)
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cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4);
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else
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cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4);
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if (cmp != 0) {
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return GSS_S_BAD_MIC;
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}
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ret = _gssapi_msg_order_check(context_handle->order, seq_number);
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if (ret) {
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return ret;
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}
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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/* copy out data */
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output_message_buffer->length = input_message_buffer->length
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- len - padlength - 8;
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output_message_buffer->value = malloc(output_message_buffer->length);
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if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
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return GSS_S_FAILURE;
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memcpy (output_message_buffer->value,
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p + 24,
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output_message_buffer->length);
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return GSS_S_COMPLETE;
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}
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#endif
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static OM_uint32
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unwrap_des3
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(OM_uint32 * minor_status,
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const gsskrb5_ctx context_handle,
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krb5_context context,
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const gss_buffer_t input_message_buffer,
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gss_buffer_t output_message_buffer,
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int * conf_state,
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gss_qop_t * qop_state,
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krb5_keyblock *key
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)
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{
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u_char *p;
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size_t len;
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u_char *seq;
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krb5_data seq_data;
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u_char cksum[20];
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uint32_t seq_number;
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size_t padlength;
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OM_uint32 ret;
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int cstate;
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krb5_crypto crypto;
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Checksum csum;
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int cmp;
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int token_len;
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if (IS_DCE_STYLE(context_handle)) {
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token_len = 34 + 8 + 15; /* 57 */
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} else {
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token_len = input_message_buffer->length;
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}
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p = input_message_buffer->value;
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ret = _gsskrb5_verify_header (&p,
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token_len,
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"\x02\x01",
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GSS_KRB5_MECHANISM);
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if (ret)
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return ret;
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if (memcmp (p, "\x04\x00", 2) != 0) /* HMAC SHA1 DES3_KD */
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return GSS_S_BAD_SIG;
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p += 2;
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if (ct_memcmp (p, "\x02\x00", 2) == 0) {
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cstate = 1;
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} else if (ct_memcmp (p, "\xff\xff", 2) == 0) {
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cstate = 0;
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} else
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return GSS_S_BAD_MIC;
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p += 2;
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if(conf_state != NULL)
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*conf_state = cstate;
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if (ct_memcmp (p, "\xff\xff", 2) != 0)
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return GSS_S_DEFECTIVE_TOKEN;
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p += 2;
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p += 28;
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len = p - (u_char *)input_message_buffer->value;
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if(cstate) {
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/* decrypt data */
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krb5_data tmp;
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ret = krb5_crypto_init(context, key,
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ETYPE_DES3_CBC_NONE, &crypto);
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if (ret) {
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*minor_status = ret;
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return GSS_S_FAILURE;
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}
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ret = krb5_decrypt(context, crypto, KRB5_KU_USAGE_SEAL,
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p, input_message_buffer->length - len, &tmp);
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krb5_crypto_destroy(context, crypto);
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if (ret) {
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*minor_status = ret;
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return GSS_S_FAILURE;
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}
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assert (tmp.length == input_message_buffer->length - len);
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memcpy (p, tmp.data, tmp.length);
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krb5_data_free(&tmp);
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}
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if (IS_DCE_STYLE(context_handle)) {
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padlength = 0;
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} else {
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/* check pad */
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ret = _gssapi_verify_pad(input_message_buffer,
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input_message_buffer->length - len,
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&padlength);
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if (ret)
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return ret;
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}
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/* verify sequence number */
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HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex);
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p -= 28;
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ret = krb5_crypto_init(context, key,
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ETYPE_DES3_CBC_NONE, &crypto);
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if (ret) {
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*minor_status = ret;
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return GSS_S_FAILURE;
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}
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{
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DES_cblock ivec;
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memcpy(&ivec, p + 8, 8);
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ret = krb5_decrypt_ivec (context,
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crypto,
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KRB5_KU_USAGE_SEQ,
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p, 8, &seq_data,
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&ivec);
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}
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krb5_crypto_destroy (context, crypto);
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if (ret) {
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*minor_status = ret;
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return GSS_S_FAILURE;
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}
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if (seq_data.length != 8) {
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krb5_data_free (&seq_data);
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*minor_status = 0;
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return GSS_S_BAD_MIC;
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}
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seq = seq_data.data;
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_gsskrb5_decode_om_uint32(seq, &seq_number);
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if (context_handle->more_flags & LOCAL)
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cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4);
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else
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cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4);
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krb5_data_free (&seq_data);
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if (cmp != 0) {
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*minor_status = 0;
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return GSS_S_BAD_MIC;
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}
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ret = _gssapi_msg_order_check(context_handle->order, seq_number);
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if (ret) {
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*minor_status = 0;
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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return ret;
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}
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HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex);
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/* verify checksum */
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memcpy (cksum, p + 8, 20);
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memcpy (p + 20, p - 8, 8);
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csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3;
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csum.checksum.length = 20;
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csum.checksum.data = cksum;
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ret = krb5_crypto_init(context, key, 0, &crypto);
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if (ret) {
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*minor_status = ret;
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return GSS_S_FAILURE;
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}
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ret = krb5_verify_checksum (context, crypto,
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KRB5_KU_USAGE_SIGN,
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p + 20,
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input_message_buffer->length - len + 8,
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&csum);
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krb5_crypto_destroy (context, crypto);
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if (ret) {
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*minor_status = ret;
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return GSS_S_FAILURE;
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}
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/* copy out data */
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output_message_buffer->length = input_message_buffer->length
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- len - padlength - 8;
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output_message_buffer->value = malloc(output_message_buffer->length);
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if(output_message_buffer->length != 0 && output_message_buffer->value == NULL)
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return GSS_S_FAILURE;
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memcpy (output_message_buffer->value,
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p + 36,
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output_message_buffer->length);
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return GSS_S_COMPLETE;
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}
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OM_uint32 GSSAPI_CALLCONV _gsskrb5_unwrap
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(OM_uint32 * minor_status,
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gss_const_ctx_id_t context_handle,
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const gss_buffer_t input_message_buffer,
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gss_buffer_t output_message_buffer,
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int * conf_state,
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gss_qop_t * qop_state
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)
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{
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krb5_keyblock *key;
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krb5_context context;
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OM_uint32 ret;
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gsskrb5_ctx ctx = (gsskrb5_ctx) context_handle;
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output_message_buffer->value = NULL;
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output_message_buffer->length = 0;
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if (qop_state != NULL)
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*qop_state = GSS_C_QOP_DEFAULT;
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GSSAPI_KRB5_INIT (&context);
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if (ctx->more_flags & IS_CFX)
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return _gssapi_unwrap_cfx (minor_status, ctx, context,
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input_message_buffer, output_message_buffer,
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conf_state, qop_state);
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HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
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ret = _gsskrb5i_get_token_key(ctx, context, &key);
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HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
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if (ret) {
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*minor_status = ret;
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return GSS_S_FAILURE;
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}
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*minor_status = 0;
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switch (key->keytype) {
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case KRB5_ENCTYPE_DES_CBC_CRC :
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case KRB5_ENCTYPE_DES_CBC_MD4 :
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case KRB5_ENCTYPE_DES_CBC_MD5 :
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#ifdef HEIM_WEAK_CRYPTO
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ret = unwrap_des (minor_status, ctx,
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input_message_buffer, output_message_buffer,
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conf_state, qop_state, key);
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#else
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ret = GSS_S_FAILURE;
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#endif
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break;
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case KRB5_ENCTYPE_DES3_CBC_MD5 :
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case KRB5_ENCTYPE_DES3_CBC_SHA1 :
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ret = unwrap_des3 (minor_status, ctx, context,
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input_message_buffer, output_message_buffer,
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conf_state, qop_state, key);
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break;
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case KRB5_ENCTYPE_ARCFOUR_HMAC_MD5:
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case KRB5_ENCTYPE_ARCFOUR_HMAC_MD5_56:
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ret = _gssapi_unwrap_arcfour (minor_status, ctx, context,
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input_message_buffer, output_message_buffer,
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conf_state, qop_state, key);
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break;
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default :
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abort();
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break;
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}
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krb5_free_keyblock (context, key);
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return ret;
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}
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