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libcli:drsuapi: Use GnuTLS MD5 in drsuapi_decrypt_attribute_value()

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
This commit is contained in:
Andreas Schneider 2019-05-15 08:07:32 +02:00 committed by Andrew Bartlett
parent 75ee0c83c1
commit 54440f1b30

View File

@ -32,6 +32,9 @@
#include "libcli/auth/libcli_auth.h" #include "libcli/auth/libcli_auth.h"
#include "dsdb/samdb/samdb.h" #include "dsdb/samdb/samdb.h"
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx, WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
const DATA_BLOB *gensec_skey, const DATA_BLOB *gensec_skey,
bool rid_crypt, bool rid_crypt,
@ -42,7 +45,7 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
DATA_BLOB confounder; DATA_BLOB confounder;
DATA_BLOB enc_buffer; DATA_BLOB enc_buffer;
MD5_CTX md5; gnutls_hash_hd_t hash_hnd = NULL;
uint8_t _enc_key[16]; uint8_t _enc_key[16];
DATA_BLOB enc_key; DATA_BLOB enc_key;
@ -53,6 +56,8 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
DATA_BLOB checked_buffer; DATA_BLOB checked_buffer;
DATA_BLOB plain_buffer; DATA_BLOB plain_buffer;
WERROR result;
int rc;
/* /*
* users with rid == 0 should not exist * users with rid == 0 should not exist
@ -79,10 +84,26 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
* not the dcerpc ncacn_ip_tcp "SystemLibraryDTC" key! * not the dcerpc ncacn_ip_tcp "SystemLibraryDTC" key!
*/ */
enc_key = data_blob_const(_enc_key, sizeof(_enc_key)); enc_key = data_blob_const(_enc_key, sizeof(_enc_key));
MD5Init(&md5);
MD5Update(&md5, gensec_skey->data, gensec_skey->length); rc = gnutls_hash_init(&hash_hnd, GNUTLS_DIG_MD5);
MD5Update(&md5, confounder.data, confounder.length); if (rc < 0) {
MD5Final(enc_key.data, &md5); result = WERR_NOT_ENOUGH_MEMORY;
goto out;
}
rc = gnutls_hash(hash_hnd, gensec_skey->data, gensec_skey->length);
if (rc < 0) {
gnutls_hash_deinit(hash_hnd, NULL);
result = WERR_INTERNAL_ERROR;
goto out;
}
rc = gnutls_hash(hash_hnd, confounder.data, confounder.length);
if (rc < 0) {
gnutls_hash_deinit(hash_hnd, NULL);
result = WERR_INTERNAL_ERROR;
goto out;
}
gnutls_hash_deinit(hash_hnd, enc_key.data);
/* /*
* copy the encrypted buffer part and * copy the encrypted buffer part and
@ -91,6 +112,8 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
dec_buffer = data_blob_const(enc_buffer.data, enc_buffer.length); dec_buffer = data_blob_const(enc_buffer.data, enc_buffer.length);
arcfour_crypt_blob(dec_buffer.data, dec_buffer.length, &enc_key); arcfour_crypt_blob(dec_buffer.data, dec_buffer.length, &enc_key);
ZERO_ARRAY_LEN(enc_key.data, enc_key.length);
/* /*
* the first 4 byte are the crc32 checksum * the first 4 byte are the crc32 checksum
* of the remaining bytes * of the remaining bytes
@ -106,7 +129,8 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
W_ERROR_HAVE_NO_MEMORY(plain_buffer.data); W_ERROR_HAVE_NO_MEMORY(plain_buffer.data);
if (crc32_given != crc32_calc) { if (crc32_given != crc32_calc) {
return W_ERROR(HRES_ERROR_V(HRES_SEC_E_DECRYPT_FAILURE)); result = W_ERROR(HRES_ERROR_V(HRES_SEC_E_DECRYPT_FAILURE));
goto out;
} }
/* /*
* The following rid_crypt obfuscation isn't session specific * The following rid_crypt obfuscation isn't session specific
@ -123,7 +147,8 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
uint32_t i, num_hashes; uint32_t i, num_hashes;
if ((checked_buffer.length % 16) != 0) { if ((checked_buffer.length % 16) != 0) {
return WERR_DS_DRA_INVALID_PARAMETER; result = WERR_DS_DRA_INVALID_PARAMETER;
goto out;
} }
num_hashes = plain_buffer.length / 16; num_hashes = plain_buffer.length / 16;
@ -134,7 +159,9 @@ WERROR drsuapi_decrypt_attribute_value(TALLOC_CTX *mem_ctx,
} }
*out = plain_buffer; *out = plain_buffer;
return WERR_OK; result = WERR_OK;
out:
return result;
} }
WERROR drsuapi_decrypt_attribute(TALLOC_CTX *mem_ctx, WERROR drsuapi_decrypt_attribute(TALLOC_CTX *mem_ctx,