diff options
Diffstat (limited to 'crypto/heimdal/lib/gssapi/verify_mic.c')
| -rw-r--r-- | crypto/heimdal/lib/gssapi/verify_mic.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/crypto/heimdal/lib/gssapi/verify_mic.c b/crypto/heimdal/lib/gssapi/verify_mic.c new file mode 100644 index 0000000..d4342a6 --- /dev/null +++ b/crypto/heimdal/lib/gssapi/verify_mic.c @@ -0,0 +1,124 @@ +/* + * Copyright (c) 1997 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "gssapi_locl.h" + +RCSID("$Id: verify_mic.c,v 1.8 1999/12/02 17:05:04 joda Exp $"); + +OM_uint32 gss_verify_mic + (OM_uint32 * minor_status, + const gss_ctx_id_t context_handle, + const gss_buffer_t message_buffer, + const gss_buffer_t token_buffer, + gss_qop_t * qop_state + ) +{ + u_char *p; + struct md5 md5; + u_char hash[16], seq_data[8]; + des_key_schedule schedule; + des_cblock key; + des_cblock zero; + int32_t seq_number; + OM_uint32 ret; + + p = token_buffer->value; + ret = gssapi_krb5_verify_header (&p, + token_buffer->length, + "\x01\x01"); + if (ret) + return ret; + + if (memcmp(p, "\x00\x00", 2) != 0) + return GSS_S_BAD_SIG; + p += 2; + if (memcmp (p, "\xff\xff\xff\xff", 4) != 0) + return GSS_S_BAD_MIC; + p += 4; + p += 16; + + /* verify checksum */ + md5_init (&md5); + md5_update (&md5, p - 24, 8); + md5_update (&md5, message_buffer->value, + message_buffer->length); + md5_finito (&md5, hash); + + memset (&zero, 0, sizeof(zero)); +#if 0 + memcpy (&key, context_handle->auth_context->key.keyvalue.data, + sizeof(key)); +#endif + memcpy (&key, context_handle->auth_context->remote_subkey->keyvalue.data, + sizeof(key)); + + des_set_key (&key, schedule); + des_cbc_cksum ((des_cblock *)hash, + (des_cblock *)hash, sizeof(hash), schedule, &zero); + if (memcmp (p - 8, hash, 8) != 0) { + memset (key, 0, sizeof(key)); + memset (schedule, 0, sizeof(schedule)); + return GSS_S_BAD_MIC; + } + + /* verify sequence number */ + + krb5_auth_getremoteseqnumber (gssapi_krb5_context, + context_handle->auth_context, + &seq_number); + seq_data[0] = (seq_number >> 0) & 0xFF; + seq_data[1] = (seq_number >> 8) & 0xFF; + seq_data[2] = (seq_number >> 16) & 0xFF; + seq_data[3] = (seq_number >> 24) & 0xFF; + memset (seq_data + 4, + (context_handle->more_flags & LOCAL) ? 0xFF : 0, + 4); + + p -= 16; + des_set_key (&key, schedule); + des_cbc_encrypt ((des_cblock *)p, (des_cblock *)p, 8, + schedule, (des_cblock *)hash, DES_DECRYPT); + + memset (key, 0, sizeof(key)); + memset (schedule, 0, sizeof(schedule)); + + if (memcmp (p, seq_data, 8) != 0) { + return GSS_S_BAD_MIC; + } + + krb5_auth_setremoteseqnumber (gssapi_krb5_context, + context_handle->auth_context, + ++seq_number); + + return GSS_S_COMPLETE; +} |
