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	Commit message (Expand)	Author	Age	Files	Lines
*	Make the test document include a Samba-specific XML element and an image.	Jelmer Vernooij	2009-05-01	1	-1/+4
*	Moving docs tree to docs-xml to make room for generated docs in the release t...	Gerald W. Carter	2008-04-23	1	-0/+21

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ /* lib/crypto/krb/checksum_confounder.c */ /* * Copyright (C) 2009 by the Massachusetts Institute of Technology. * All rights reserved. * * Export of this software from the United States of America may * require a specific license from the United States Government. * It is the responsibility of any person or organization contemplating * export to obtain such a license before exporting. * * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and * distribute this software and its documentation for any purpose and * without fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright notice and * this permission notice appear in supporting documentation, and that * the name of M.I.T. not be used in advertising or publicity pertaining * to distribution of the software without specific, written prior * permission. Furthermore if you modify this software you must label * your software as modified software and not distribute it in such a * fashion that it might be confused with the original M.I.T. software. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" without express * or implied warranty. */ /* * Confounder checksum implementation, using tokens of the form: * enc(xorkey, confounder | hash(confounder | data)) * where xorkey is the key XOR'd with 0xf0 bytes. */ #include "crypto_int.h" /* Derive a key by XOR with 0xF0 bytes. */ static krb5_error_code mk_xorkey(krb5_key origkey, krb5_key *xorkey) { krb5_error_code retval = 0; unsigned char *xorbytes; krb5_keyblock xorkeyblock; size_t i = 0; xorbytes = k5memdup(origkey->keyblock.contents, origkey->keyblock.length, &retval); if (xorbytes == NULL) return retval; for (i = 0; i < origkey->keyblock.length; i++) xorbytes[i] ^= 0xf0; /* Do a shallow copy here. */ xorkeyblock = origkey->keyblock; xorkeyblock.contents = xorbytes; retval = krb5_k_create_key(0, &xorkeyblock, xorkey); zapfree(xorbytes, origkey->keyblock.length); return retval; } krb5_error_code krb5int_confounder_checksum(const struct krb5_cksumtypes *ctp, krb5_key key, krb5_keyusage usage, const krb5_crypto_iov *data, size_t num_data, krb5_data *output) { krb5_error_code ret; krb5_data conf, hashval; krb5_key xorkey = NULL; krb5_crypto_iov *hash_iov, iov; size_t blocksize = ctp->enc->block_size, hashsize = ctp->hash->hashsize; /* Partition the output buffer into confounder and hash. */ conf = make_data(output->data, blocksize); hashval = make_data(output->data + blocksize, hashsize); /* Create the confounder. */ ret = krb5_c_random_make_octets(NULL, &conf); if (ret != 0) return ret; ret = mk_xorkey(key, &xorkey); if (ret) return ret; /* Hash the confounder, then the input data. */ hash_iov = k5calloc(num_data + 1, sizeof(krb5_crypto_iov), &ret); if (hash_iov == NULL) goto cleanup; hash_iov[0].flags = KRB5_CRYPTO_TYPE_DATA; hash_iov[0].data = conf; memcpy(hash_iov + 1, data, num_data * sizeof(krb5_crypto_iov)); ret = ctp->hash->hash(hash_iov, num_data + 1, &hashval); if (ret != 0) goto cleanup; /* Confounder and hash are in output buffer; encrypt them in place. */ iov.flags = KRB5_CRYPTO_TYPE_DATA; iov.data = *output; ret = ctp->enc->encrypt(xorkey, NULL, &iov, 1); cleanup: free(hash_iov); krb5_k_free_key(NULL, xorkey); return ret; } krb5_error_code krb5int_confounder_verify(const struct krb5_cksumtypes *ctp, krb5_key key, krb5_keyusage usage, const krb5_crypto_iov *data, size_t num_data, const krb5_data *input, krb5_boolean *valid) { krb5_error_code ret; unsigned char *plaintext = NULL; krb5_key xorkey = NULL; krb5_data computed = empty_data(); krb5_crypto_iov *hash_iov = NULL, iov; size_t blocksize = ctp->enc->block_size, hashsize = ctp->hash->hashsize; plaintext = k5memdup(input->data, input->length, &ret); if (plaintext == NULL) return ret; ret = mk_xorkey(key, &xorkey); if (ret != 0) goto cleanup; /* Decrypt the input checksum. */ iov.flags = KRB5_CRYPTO_TYPE_DATA; iov.data = make_data(plaintext, input->length); ret = ctp->enc->decrypt(xorkey, NULL, &iov, 1); if (ret != 0) goto cleanup; /* Hash the confounder, then the input data. */ hash_iov = k5calloc(num_data + 1, sizeof(krb5_crypto_iov), &ret); if (hash_iov == NULL) goto cleanup; hash_iov[0].flags = KRB5_CRYPTO_TYPE_DATA; hash_iov[0].data = make_data(plaintext, blocksize); memcpy(hash_iov + 1, data, num_data * sizeof(krb5_crypto_iov)); ret = alloc_data(&computed, hashsize); if (ret != 0) goto cleanup; ret = ctp->hash->hash(hash_iov, num_data + 1, &computed); if (ret != 0) goto cleanup; /* Compare the decrypted hash to the computed one. */ *valid = (memcmp(plaintext + blocksize, computed.data, hashsize) == 0); cleanup: zapfree(plaintext, input->length); zapfree(computed.data, hashsize); free(hash_iov); krb5_k_free_key(NULL, xorkey); return ret; }