/* $NetBSD: crypto-pk.c,v 1.2 2017/01/28 21:31:49 christos Exp $ */
/*
* Copyright (c) 1997 - 2008 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 "krb5_locl.h"
#include <krb5/pkinit_asn1.h>
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_pk_octetstring2key(krb5_context context,
krb5_enctype type,
const void *dhdata,
size_t dhsize,
const heim_octet_string *c_n,
const heim_octet_string *k_n,
krb5_keyblock *key)
{
struct _krb5_encryption_type *et = _krb5_find_enctype(type);
krb5_error_code ret;
size_t keylen, offset;
void *keydata;
unsigned char counter;
unsigned char shaoutput[SHA_DIGEST_LENGTH];
EVP_MD_CTX *m;
if(et == NULL) {
krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
N_("encryption type %d not supported", ""),
type);
return KRB5_PROG_ETYPE_NOSUPP;
}
keylen = (et->keytype->bits + 7) / 8;
keydata = malloc(keylen);
if (keydata == NULL)
return krb5_enomem(context);
m = EVP_MD_CTX_create();
if (m == NULL) {
free(keydata);
return krb5_enomem(context);
}
counter = 0;
offset = 0;
do {
EVP_DigestInit_ex(m, EVP_sha1(), NULL);
EVP_DigestUpdate(m, &counter, 1);
EVP_DigestUpdate(m, dhdata, dhsize);
if (c_n)
EVP_DigestUpdate(m, c_n->data, c_n->length);
if (k_n)
EVP_DigestUpdate(m, k_n->data, k_n->length);
EVP_DigestFinal_ex(m, shaoutput, NULL);
memcpy((unsigned char *)keydata + offset,
shaoutput,
min(keylen - offset, sizeof(shaoutput)));
offset += sizeof(shaoutput);
counter++;
} while(offset < keylen);
memset(shaoutput, 0, sizeof(shaoutput));
EVP_MD_CTX_destroy(m);
ret = krb5_random_to_key(context, type, keydata, keylen, key);
memset(keydata, 0, sizeof(keylen));
free(keydata);
return ret;
}
static krb5_error_code
encode_uvinfo(krb5_context context, krb5_const_principal p, krb5_data *data)
{
KRB5PrincipalName pn;
krb5_error_code ret;
size_t size = 0;
pn.principalName = p->name;
pn.realm = p->realm;
ASN1_MALLOC_ENCODE(KRB5PrincipalName, data->data, data->length,
&pn, &size, ret);
if (ret) {
krb5_data_zero(data);
krb5_set_error_message(context, ret,
N_("Failed to encode KRB5PrincipalName", ""));
return ret;
}
if (data->length != size)
krb5_abortx(context, "asn1 compiler internal error");
return 0;
}
static krb5_error_code
encode_otherinfo(krb5_context context,
const AlgorithmIdentifier *ai,
krb5_const_principal client,
krb5_const_principal server,
krb5_enctype enctype,
const krb5_data *as_req,
const krb5_data *pk_as_rep,
const Ticket *ticket,
krb5_data *other)
{
PkinitSP80056AOtherInfo otherinfo;
PkinitSuppPubInfo pubinfo;
krb5_error_code ret;
krb5_data pub;
size_t size = 0;
krb5_data_zero(other);
memset(&otherinfo, 0, sizeof(otherinfo));
memset(&pubinfo, 0, sizeof(pubinfo));
pubinfo.enctype = enctype;
pubinfo.as_REQ = *as_req;
pubinfo.pk_as_rep = *pk_as_rep;
pubinfo.ticket = *ticket;
ASN1_MALLOC_ENCODE(PkinitSuppPubInfo, pub.data, pub.length,
&pubinfo, &size, ret);
if (ret) {
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
return ret;
}
if (pub.length != size)
krb5_abortx(context, "asn1 compiler internal error");
ret = encode_uvinfo(context, client, &otherinfo.partyUInfo);
if (ret) {
free(pub.data);
return ret;
}
ret = encode_uvinfo(context, server, &otherinfo.partyVInfo);
if (ret) {
free(otherinfo.partyUInfo.data);
free(pub.data);
return ret;
}
otherinfo.algorithmID = *ai;
otherinfo.suppPubInfo = &pub;
ASN1_MALLOC_ENCODE(PkinitSP80056AOtherInfo, other->data, other->length,
&otherinfo, &size, ret);
free(otherinfo.partyUInfo.data);
free(otherinfo.partyVInfo.data);
free(pub.data);
if (ret) {
krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
return ret;
}
if (other->length != size)
krb5_abortx(context, "asn1 compiler internal error");
return 0;
}
KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_pk_kdf(krb5_context context,
const struct AlgorithmIdentifier *ai,
const void *dhdata,
size_t dhsize,
krb5_const_principal client,
krb5_const_principal server,
krb5_enctype enctype,
const krb5_data *as_req,
const krb5_data *pk_as_rep,
const Ticket *ticket,
krb5_keyblock *key)
{
struct _krb5_encryption_type *et;
krb5_error_code ret;
krb5_data other;
size_t keylen, offset;
uint32_t counter;
unsigned char *keydata;
unsigned char shaoutput[SHA512_DIGEST_LENGTH];
const EVP_MD *md;
EVP_MD_CTX *m;
if (der_heim_oid_cmp(&asn1_oid_id_pkinit_kdf_ah_sha1, &ai->algorithm) == 0) {
md = EVP_sha1();
} else if (der_heim_oid_cmp(&asn1_oid_id_pkinit_kdf_ah_sha256, &ai->algorithm) == 0) {
md = EVP_sha256();
} else if (der_heim_oid_cmp(&asn1_oid_id_pkinit_kdf_ah_sha512, &ai->algorithm) == 0) {
md = EVP_sha512();
} else {
krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
N_("KDF not supported", ""));
return KRB5_PROG_ETYPE_NOSUPP;
}
if (ai->parameters != NULL &&
(ai->parameters->length != 2 ||
memcmp(ai->parameters->data, "\x05\x00", 2) != 0))
{
krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
N_("kdf params not NULL or the NULL-type",
""));
return KRB5_PROG_ETYPE_NOSUPP;
}
et = _krb5_find_enctype(enctype);
if(et == NULL) {
krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP,
N_("encryption type %d not supported", ""),
enctype);
return KRB5_PROG_ETYPE_NOSUPP;
}
keylen = (et->keytype->bits + 7) / 8;
keydata = malloc(keylen);
if (keydata == NULL)
return krb5_enomem(context);
ret = encode_otherinfo(context, ai, client, server,
enctype, as_req, pk_as_rep, ticket, &other);
if (ret) {
free(keydata);
return ret;
}
m = EVP_MD_CTX_create();
if (m == NULL) {
free(keydata);
free(other.data);
return krb5_enomem(context);
}
offset = 0;
counter = 1;
do {
unsigned char cdata[4];
EVP_DigestInit_ex(m, md, NULL);
_krb5_put_int(cdata, counter, 4);
EVP_DigestUpdate(m, cdata, 4);
EVP_DigestUpdate(m, dhdata, dhsize);
EVP_DigestUpdate(m, other.data, other.length);
EVP_DigestFinal_ex(m, shaoutput, NULL);
memcpy((unsigned char *)keydata + offset,
shaoutput,
min(keylen - offset, EVP_MD_CTX_size(m)));
offset += EVP_MD_CTX_size(m);
counter++;
} while(offset < keylen);
memset(shaoutput, 0, sizeof(shaoutput));
EVP_MD_CTX_destroy(m);
free(other.data);
ret = krb5_random_to_key(context, enctype, keydata, keylen, key);
memset(keydata, 0, sizeof(keylen));
free(keydata);
return ret;
}