6b1ad83a22
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@2016 ec53bebd-3082-4978-b11e-865c3cabbd6b
81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
#include <krb5_locl.h>
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#include "crc.h"
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RCSID("$Id$");
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krb5_error_code
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krb5_des_cbc_decrypt(krb5_context context,
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void *ptr,
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size_t len,
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int etype,
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const krb5_keyblock *keyblock,
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krb5_data *result)
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{
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u_char *p = (u_char *)ptr;
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size_t offset;
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des_cblock key;
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des_key_schedule schedule;
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memcpy (&key, keyblock->keyvalue.data, sizeof(key));
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des_set_key (&key, schedule);
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des_cbc_encrypt ((des_cblock *)ptr, (des_cblock *)ptr, len,
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schedule, &key, DES_DECRYPT);
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switch(etype){
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case ETYPE_DES_CBC_MD5:
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{
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struct md5 m;
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u_int32_t his_checksum[4];
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u_int32_t my_checksum[4];
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memcpy(his_checksum, p + 8, 16);
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memset(p + 8, 0, 16);
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md5_init(&m);
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md5_update (&m, ptr, len);
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md5_finito(&m, my_checksum);
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if(memcmp(his_checksum, my_checksum, 16))
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return KRB5KRB_AP_ERR_BAD_INTEGRITY;
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offset = 24;
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}
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break;
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case ETYPE_DES_CBC_CRC:
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{
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u_int32_t my_crc, her_crc;
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her_crc = (p[11] << 24) | (p[10] << 16) |
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(p[9] << 8) | (p[8] << 0);
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memset (p + 8, 0, sizeof(her_crc));
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crc_init_table ();
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my_crc = crc_update (ptr, len, 0);
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if (my_crc != her_crc)
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return KRB5KRB_AP_ERR_BAD_INTEGRITY;
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offset = 12;
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}
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break;
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default:
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return KRB5_PROG_ETYPE_NOSUPP;
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}
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result->length = len - offset;
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result->data = malloc(result->length);
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if (result->data == NULL)
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return ENOMEM;
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memcpy(result->data, p + 12, result->length);
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return 0;
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}
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krb5_error_code
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krb5_decrypt (krb5_context context,
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void *ptr,
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size_t len,
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int etype,
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const krb5_keyblock *keyblock,
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krb5_data *result)
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{
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switch(etype){
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case ETYPE_DES_CBC_CRC:
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case ETYPE_DES_CBC_MD5:
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return krb5_des_cbc_decrypt(context, ptr, len, etype, keyblock,
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result);
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}
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return KRB5_PROG_ETYPE_NOSUPP;
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}
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