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#include "k5-int.h"
#include "rsa-md5.h"
#include "des_int.h" /* we cheat a bit and call it directly... */
/* Windows needs to these prototypes for the assignment below */
krb5_error_code
krb5_md5_crypto_sum_func PROTOTYPE((krb5_pointer in, size_t in_length,
krb5_pointer seed, size_t seed_length, krb5_checksum FAR *outcksum));
krb5_error_code
krb5_md5_crypto_verify_func PROTOTYPE((krb5_checksum FAR *cksum, krb5_pointer in,
size_t in_length, krb5_pointer seed, size_t seed_length));
/*
* In Kerberos V5 Beta 5 and previous releases the RSA-MD5-DES implementation
* did not follow RFC1510. The folowing definitions control the compatibility
* with these releases.
*
* If MD5_K5BETA_COMPAT is defined, then compatability mode is enabled. That
* means that both checksum functions are compiled and available for use and
* the additional interface krb5_md5_crypto_compat_ctl() is defined.
*
* If MD5_K5BETA_COMPAT_DEF is defined and compatability mode is enabled, then
* the compatible behaviour becomes the default.
*
*/
static void
krb5_md5_calculate_cksum(md5ctx, in, in_length, confound, confound_length)
krb5_MD5_CTX *md5ctx;
krb5_pointer in;
size_t in_length;
krb5_pointer confound;
size_t confound_length;
{
krb5_MD5Init(md5ctx);
if (confound && confound_length)
krb5_MD5Update(md5ctx, confound, confound_length);
krb5_MD5Update(md5ctx, in, in_length);
krb5_MD5Final(md5ctx);
}
#ifdef MD5_K5BETA_COMPAT
krb5_error_code
krb5_md5_crypto_compat_sum_func(in, in_length, seed, seed_length, outcksum)
krb5_pointer in;
size_t in_length;
krb5_pointer seed;
size_t seed_length;
krb5_checksum FAR *outcksum;
{
krb5_octet outtmp[RSA_MD5_DES_CKSUM_LENGTH];
krb5_octet *input = (krb5_octet *)in;
krb5_encrypt_block eblock;
krb5_keyblock keyblock;
krb5_error_code retval;
krb5_MD5_CTX working;
krb5_MD5Init(&working);
krb5_MD5Update(&working, input, in_length);
krb5_MD5Final(&working);
outcksum->checksum_type = CKSUMTYPE_RSA_MD5_DES;
outcksum->length = RSA_MD5_DES_CKSUM_LENGTH;
memcpy((char *)outtmp, (char *)&working.digest[0], 16);
memset((char *)&working, 0, sizeof(working));
keyblock.length = seed_length;
keyblock.contents = (krb5_octet *)seed;
keyblock.enctype = ENCTYPE_DES_CBC_MD5;
if ((retval = mit_des_process_key(&eblock, &keyblock)))
return retval;
/* now encrypt it */
retval = mit_des_cbc_encrypt((mit_des_cblock *)&outtmp[0],
(mit_des_cblock *)outcksum->contents,
RSA_MD5_DES_CKSUM_LENGTH,
(struct mit_des_ks_struct *)eblock.priv,
keyblock.contents,
MIT_DES_ENCRYPT);
if (retval) {
(void) mit_des_finish_key(&eblock);
return retval;
}
return mit_des_finish_key(&eblock);
}
#endif /* MD5_K5BETA_COMPAT */
krb5_error_code
krb5_md5_crypto_sum_func(in, in_length, seed, seed_length, outcksum)
krb5_pointer in;
size_t in_length;
krb5_pointer seed;
size_t seed_length;
krb5_checksum FAR *outcksum;
{
krb5_octet outtmp[RSA_MD5_DES_CKSUM_LENGTH+
RSA_MD5_DES_CONFOUND_LENGTH];
mit_des_cblock tmpkey;
krb5_octet *input = (krb5_octet *)in;
krb5_encrypt_block eblock;
krb5_keyblock keyblock;
krb5_error_code retval;
size_t i;
krb5_MD5_CTX working;
/* Generate the confounder in place */
if (retval = krb5_random_confounder(RSA_MD5_DES_CONFOUND_LENGTH,
outtmp))
return(retval);
/* Calculate the checksum */
krb5_md5_calculate_cksum(&working,
(krb5_pointer) outtmp,
(size_t) RSA_MD5_DES_CONFOUND_LENGTH,
in,
in_length);
outcksum->checksum_type = CKSUMTYPE_RSA_MD5_DES;
outcksum->length = RSA_MD5_DES_CKSUM_LENGTH + RSA_MD5_DES_CONFOUND_LENGTH;
/* Now blast in the digest */
memcpy((char *)&outtmp[RSA_MD5_DES_CONFOUND_LENGTH],
(char *)&working.digest[0],
RSA_MD5_DES_CKSUM_LENGTH);
/* Clean up the droppings */
memset((char *)&working, 0, sizeof(working));
/* Set up the temporary copy of the key (see RFC 1510 section 6.4.5) */
memset((char *) tmpkey, 0, sizeof(mit_des_cblock));
for (i=0; (i<seed_length) && (i<sizeof(mit_des_cblock)); i++)
tmpkey[i] = (((krb5_octet *) seed)[i]) ^ 0xf0;
keyblock.length = sizeof(mit_des_cblock);
keyblock.contents = (krb5_octet *) tmpkey;
keyblock.enctype = ENCTYPE_DES_CBC_MD5;
if ((retval = mit_des_process_key(&eblock, &keyblock)))
return retval;
/* now encrypt it */
retval = mit_des_cbc_encrypt((mit_des_cblock *)&outtmp[0],
(mit_des_cblock *)outcksum->contents,
RSA_MD5_DES_CKSUM_LENGTH +
RSA_MD5_DES_CONFOUND_LENGTH,
(struct mit_des_ks_struct *)eblock.priv,
keyblock.contents,
MIT_DES_ENCRYPT);
if (retval) {
(void) mit_des_finish_key(&eblock);
return retval;
}
return mit_des_finish_key(&eblock);
}
krb5_error_code
krb5_md5_crypto_verify_func(cksum, in, in_length, seed, seed_length)
krb5_checksum FAR *cksum;
krb5_pointer in;
size_t in_length;
krb5_pointer seed;
size_t seed_length;
{
krb5_octet outtmp[RSA_MD5_DES_CKSUM_LENGTH+
RSA_MD5_DES_CONFOUND_LENGTH];
mit_des_cblock tmpkey;
krb5_octet *input = (krb5_octet *)in;
krb5_encrypt_block eblock;
krb5_keyblock keyblock;
krb5_error_code retval;
size_t i;
krb5_MD5_CTX working;
retval = 0;
if (cksum->checksum_type == CKSUMTYPE_RSA_MD5_DES) {
#ifdef MD5_K5BETA_COMPAT
/*
* We have a backwards compatibility problem here. Kerberos version 5
* Beta 5 and previous releases did not correctly generate RSA-MD5-DES
* checksums. The way that we can differentiate is by the length of
* the provided checksum. If it's only RSA_MD5_DES_CKSUM_LENGTH, then
* it's the old style, otherwise it's the correct implementation.
*/
if (cksum->length == RSA_MD5_DES_CKSUM_LENGTH) {
/*
* If we're verifying the Old Style (tm) checksum, then we can just
* recalculate the checksum and encrypt it and see if it's the
* same.
*/
/* Recalculate the checksum with no confounder */
krb5_md5_calculate_cksum(&working,
(krb5_pointer) NULL,
(size_t) 0,
in,
in_length);
/* Use the key "as-is" */
keyblock.length = seed_length;
keyblock.contents = (krb5_octet *) seed;
keyblock.enctype = ENCTYPE_DES_CBC_MD5;
if ((retval = mit_des_process_key(&eblock, &keyblock)))
return retval;
/* now encrypt the checksum */
retval = mit_des_cbc_encrypt((mit_des_cblock *)&working.digest[0],
(mit_des_cblock *)&outtmp[0],
RSA_MD5_DES_CKSUM_LENGTH,
(struct mit_des_ks_struct *)
eblock.priv,
keyblock.contents,
MIT_DES_ENCRYPT);
if (retval) {
(void) mit_des_finish_key(&eblock);
return retval;
}
if (retval = mit_des_finish_key(&eblock))
return(retval);
/* Compare the encrypted checksums */
if (memcmp((char *) &outtmp[0],
(char *) cksum->contents,
RSA_MD5_DES_CKSUM_LENGTH))
retval = KRB5KRB_AP_ERR_BAD_INTEGRITY;
}
else
#endif /* MD5_K5BETA_COMPAT */
if (cksum->length == (RSA_MD5_DES_CKSUM_LENGTH +
RSA_MD5_DES_CONFOUND_LENGTH)) {
/*
* If we're verifying the correct implementation, then we have
* to do a little more work because we must decrypt the checksum
* because it contains the confounder in it. So, figure out
* what our key variant is and then do it!
*/
/* Set up the variant of the key (see RFC 1510 section 6.4.5) */
memset((char *) tmpkey, 0, sizeof(mit_des_cblock));
for (i=0; (i<seed_length) && (i<sizeof(mit_des_cblock)); i++)
tmpkey[i] = (((krb5_octet *) seed)[i]) ^ 0xf0;
keyblock.length = sizeof(mit_des_cblock);
keyblock.contents = (krb5_octet *) tmpkey;
keyblock.enctype = ENCTYPE_DES_CBC_MD5;
if ((retval = mit_des_process_key(&eblock, &keyblock)))
return retval;
/* now decrypt it */
retval = mit_des_cbc_encrypt((mit_des_cblock *)cksum->contents,
(mit_des_cblock *)&outtmp[0],
RSA_MD5_DES_CKSUM_LENGTH +
RSA_MD5_DES_CONFOUND_LENGTH,
(struct mit_des_ks_struct *)
eblock.priv,
keyblock.contents,
MIT_DES_DECRYPT);
if (retval) {
(void) mit_des_finish_key(&eblock);
return retval;
}
if (retval = mit_des_finish_key(&eblock))
return(retval);
/* Now that we have the decrypted checksum, try to regenerate it */
krb5_md5_calculate_cksum(&working,
(krb5_pointer) outtmp,
(size_t) RSA_MD5_DES_CONFOUND_LENGTH,
in,
in_length);
/* Compare the checksums */
if (memcmp((char *) &outtmp[RSA_MD5_DES_CONFOUND_LENGTH],
(char *) &working.digest[0],
RSA_MD5_DES_CKSUM_LENGTH))
retval = KRB5KRB_AP_ERR_BAD_INTEGRITY;
}
else
retval = KRB5KRB_AP_ERR_BAD_INTEGRITY;
}
#if CKSUMTYPE_RSA_MD5_DES3
else if (cksum->checksum_type == CKSUMTYPE_RSA_MD5_DES3) {
if (cksum->length == (RSA_MD5_DES_CKSUM_LENGTH +
RSA_MD5_DES_CONFOUND_LENGTH)) {
/*
* If we're verifying the correct implementation, then we have
* to do a little more work because we must decrypt the checksum
* because it contains the confounder in it. So, figure out
* what our key variant is and then do it!
*/
/* Set up the variant of the key (see RFC 1510 section 6.4.5) */
memset((char *) tmpkey, 0, sizeof(mit_des_cblock));
for (i=0; (i<seed_length) && (i<sizeof(mit_des_cblock)); i++)
tmpkey[i] = (((krb5_octet *) seed)[i]) ^ 0xf0;
keyblock.length = sizeof(mit_des3_cblock);
keyblock.contents = (krb5_octet *) tmpkey;
keyblock.enctype = ENCTYPE_DES3_CBC_MD5;
if ((retval = mit_des3_process_key(&eblock, &keyblock)))
return retval;
/* now decrypt it */
retval = mit_des3_cbc_encrypt((mit_des_cblock *)cksum->contents,
(mit_des_cblock *)&outtmp[0],
RSA_MD5_DES_CKSUM_LENGTH +
RSA_MD5_DES_CONFOUND_LENGTH,
(struct mit_des_ks_struct *)
eblock.priv,
((struct mit_des_ks_struct *)
eblock.priv) + 1,
((struct mit_des_ks_struct *)
eblock.priv) + 2,
keyblock.contents,
MIT_DES_DECRYPT);
if (retval) {
(void) mit_des_finish_key(&eblock);
return retval;
}
if (retval = mit_des_finish_key(&eblock))
return(retval);
/* Now that we have the decrypted checksum, try to regenerate it */
krb5_md5_calculate_cksum(&working,
(krb5_pointer) outtmp,
(size_t) RSA_MD5_DES_CONFOUND_LENGTH,
in,
in_length);
/* Compare the checksums */
if (memcmp((char *) &outtmp[RSA_MD5_DES_CONFOUND_LENGTH],
(char *) &working.digest[0],
RSA_MD5_DES_CKSUM_LENGTH))
retval = KRB5KRB_AP_ERR_BAD_INTEGRITY;
}
else
retval = KRB5KRB_AP_ERR_BAD_INTEGRITY;
}
#endif /* CKSUMTYPE_RSA_MD5_DES3 */
else
retval = KRB5KRB_AP_ERR_INAPP_CKSUM;
/* Clean up droppings */
memset((char *)&working, 0, sizeof(working));
return(retval);
}
krb5_checksum_entry rsa_md5_des_cksumtable_entry =
#if defined(MD5_K5BETA_COMPAT) && defined(MD5_K5BETA_COMPAT_DEF)
{
0,
krb5_md5_crypto_compat_sum_func,
krb5_md5_crypto_verify_func,
RSA_MD5_DES_CKSUM_LENGTH,
1, /* is collision proof */
1, /* uses key */
};
#else /* MD5_K5BETA_COMPAT && MD5_K5BETA_COMPAT_DEF */
{
0,
krb5_md5_crypto_sum_func,
krb5_md5_crypto_verify_func,
RSA_MD5_DES_CKSUM_LENGTH+RSA_MD5_DES_CONFOUND_LENGTH,
1, /* is collision proof */
1, /* uses key */
};
#endif /* MD5_K5BETA_COMPAT && MD5_K5BETA_COMPAT_DEF */
#ifdef MD5_K5BETA_COMPAT
/*
* Turn on/off compatible checksum generation.
*/
void
krb5_md5_crypto_compat_ctl(scompat)
krb5_boolean scompat;
{
if (scompat) {
rsa_md5_des_cksumtable_entry.sum_func = krb5_md5_crypto_compat_sum_func;
rsa_md5_des_cksumtable_entry.checksum_length =
RSA_MD5_DES_CKSUM_LENGTH;
}
else {
rsa_md5_des_cksumtable_entry.sum_func = krb5_md5_crypto_sum_func;
rsa_md5_des_cksumtable_entry.checksum_length =
RSA_MD5_DES_CKSUM_LENGTH + RSA_MD5_DES_CONFOUND_LENGTH;
}
}
#endif /* MD5_K5BETA_COMPAT */
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