openssl/crypto/rand/drbg_hmac.c
Matt Caswell 53a11c6da0 Change the DRBG HMAC implementation to lookup allowed digest names
As per the previous commit we make the same change for DRBG HMAC and
more closely align the FIPS_MODE and non FIPS_MODE implementations.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/9035)
2019-06-28 10:22:21 +01:00

270 lines
8.8 KiB
C

/*
* Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdlib.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "internal/thread_once.h"
#include "internal/providercommon.h"
#include "rand_lcl.h"
/*
* Called twice by SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process.
*
* hmac is an object that holds the input/output Key and Value (K and V).
* inbyte is 0x00 on the first call and 0x01 on the second call.
* in1, in2, in3 are optional inputs that can be NULL.
* in1len, in2len, in3len are the lengths of the input buffers.
*
* The returned K,V is:
* hmac->K = HMAC(hmac->K, hmac->V || inbyte || [in1] || [in2] || [in3])
* hmac->V = HMAC(hmac->K, hmac->V)
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int do_hmac(RAND_DRBG_HMAC *hmac, unsigned char inbyte,
const unsigned char *in1, size_t in1len,
const unsigned char *in2, size_t in2len,
const unsigned char *in3, size_t in3len)
{
HMAC_CTX *ctx = hmac->ctx;
return HMAC_Init_ex(ctx, hmac->K, hmac->blocklen, hmac->md, NULL)
/* K = HMAC(K, V || inbyte || [in1] || [in2] || [in3]) */
&& HMAC_Update(ctx, hmac->V, hmac->blocklen)
&& HMAC_Update(ctx, &inbyte, 1)
&& (in1 == NULL || in1len == 0 || HMAC_Update(ctx, in1, in1len))
&& (in2 == NULL || in2len == 0 || HMAC_Update(ctx, in2, in2len))
&& (in3 == NULL || in3len == 0 || HMAC_Update(ctx, in3, in3len))
&& HMAC_Final(ctx, hmac->K, NULL)
/* V = HMAC(K, V) */
&& HMAC_Init_ex(ctx, hmac->K, hmac->blocklen, hmac->md, NULL)
&& HMAC_Update(ctx, hmac->V, hmac->blocklen)
&& HMAC_Final(ctx, hmac->V, NULL);
}
/*
* SP800-90Ar1 10.1.2.2 HMAC_DRBG_Update_Process
*
*
* Updates the drbg objects Key(K) and Value(V) using the following algorithm:
* K,V = do_hmac(hmac, 0, in1, in2, in3)
* if (any input is not NULL)
* K,V = do_hmac(hmac, 1, in1, in2, in3)
*
* where in1, in2, in3 are optional input buffers that can be NULL.
* in1len, in2len, in3len are the lengths of the input buffers.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hmac_update(RAND_DRBG *drbg,
const unsigned char *in1, size_t in1len,
const unsigned char *in2, size_t in2len,
const unsigned char *in3, size_t in3len)
{
RAND_DRBG_HMAC *hmac = &drbg->data.hmac;
/* (Steps 1-2) K = HMAC(K, V||0x00||provided_data). V = HMAC(K,V) */
if (!do_hmac(hmac, 0x00, in1, in1len, in2, in2len, in3, in3len))
return 0;
/* (Step 3) If provided_data == NULL then return (K,V) */
if (in1len == 0 && in2len == 0 && in3len == 0)
return 1;
/* (Steps 4-5) K = HMAC(K, V||0x01||provided_data). V = HMAC(K,V) */
return do_hmac(hmac, 0x01, in1, in1len, in2, in2len, in3, in3len);
}
/*
* SP800-90Ar1 10.1.2.3 HMAC_DRBG_Instantiate_Process:
*
* This sets the drbg Key (K) to all zeros, and Value (V) to all 1's.
* and then calls (K,V) = drbg_hmac_update() with input parameters:
* ent = entropy data (Can be NULL) of length ent_len.
* nonce = nonce data (Can be NULL) of length nonce_len.
* pstr = personalization data (Can be NULL) of length pstr_len.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hmac_instantiate(RAND_DRBG *drbg,
const unsigned char *ent, size_t ent_len,
const unsigned char *nonce, size_t nonce_len,
const unsigned char *pstr, size_t pstr_len)
{
RAND_DRBG_HMAC *hmac = &drbg->data.hmac;
/* (Step 2) Key = 0x00 00...00 */
memset(hmac->K, 0x00, hmac->blocklen);
/* (Step 3) V = 0x01 01...01 */
memset(hmac->V, 0x01, hmac->blocklen);
/* (Step 4) (K,V) = HMAC_DRBG_Update(entropy||nonce||pers string, K, V) */
return drbg_hmac_update(drbg, ent, ent_len, nonce, nonce_len, pstr,
pstr_len);
}
/*
* SP800-90Ar1 10.1.2.4 HMAC_DRBG_Reseed_Process:
*
* Reseeds the drbg's Key (K) and Value (V) by calling
* (K,V) = drbg_hmac_update() with the following input parameters:
* ent = entropy input data (Can be NULL) of length ent_len.
* adin = additional input data (Can be NULL) of length adin_len.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hmac_reseed(RAND_DRBG *drbg,
const unsigned char *ent, size_t ent_len,
const unsigned char *adin, size_t adin_len)
{
/* (Step 2) (K,V) = HMAC_DRBG_Update(entropy||additional_input, K, V) */
return drbg_hmac_update(drbg, ent, ent_len, adin, adin_len, NULL, 0);
}
/*
* SP800-90Ar1 10.1.2.5 HMAC_DRBG_Generate_Process:
*
* Generates pseudo random bytes and updates the internal K,V for the drbg.
* out is a buffer to fill with outlen bytes of pseudo random data.
* adin is an additional_input string of size adin_len that may be NULL.
*
* Returns zero if an error occurs otherwise it returns 1.
*/
static int drbg_hmac_generate(RAND_DRBG *drbg,
unsigned char *out, size_t outlen,
const unsigned char *adin, size_t adin_len)
{
RAND_DRBG_HMAC *hmac = &drbg->data.hmac;
HMAC_CTX *ctx = hmac->ctx;
const unsigned char *temp = hmac->V;
/* (Step 2) if adin != NULL then (K,V) = HMAC_DRBG_Update(adin, K, V) */
if (adin != NULL
&& adin_len > 0
&& !drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
return 0;
/*
* (Steps 3-5) temp = NULL
* while (len(temp) < outlen) {
* V = HMAC(K, V)
* temp = temp || V
* }
*/
for (;;) {
if (!HMAC_Init_ex(ctx, hmac->K, hmac->blocklen, hmac->md, NULL)
|| !HMAC_Update(ctx, temp, hmac->blocklen))
return 0;
if (outlen > hmac->blocklen) {
if (!HMAC_Final(ctx, out, NULL))
return 0;
temp = out;
} else {
if (!HMAC_Final(ctx, hmac->V, NULL))
return 0;
memcpy(out, hmac->V, outlen);
break;
}
out += hmac->blocklen;
outlen -= hmac->blocklen;
}
/* (Step 6) (K,V) = HMAC_DRBG_Update(adin, K, V) */
if (!drbg_hmac_update(drbg, adin, adin_len, NULL, 0, NULL, 0))
return 0;
return 1;
}
static int drbg_hmac_uninstantiate(RAND_DRBG *drbg)
{
EVP_MD_meth_free(drbg->data.hmac.md);
HMAC_CTX_free(drbg->data.hmac.ctx);
OPENSSL_cleanse(&drbg->data.hmac, sizeof(drbg->data.hmac));
return 1;
}
static RAND_DRBG_METHOD drbg_hmac_meth = {
drbg_hmac_instantiate,
drbg_hmac_reseed,
drbg_hmac_generate,
drbg_hmac_uninstantiate
};
int drbg_hmac_init(RAND_DRBG *drbg)
{
EVP_MD *md = NULL;
RAND_DRBG_HMAC *hmac = &drbg->data.hmac;
/*
* Confirm digest is allowed. Outside FIPS_MODE we allow all non-legacy
* digests. Inside FIPS_MODE we only allow approved digests. Also no XOF
* digests (such as SHAKE).
*/
switch (drbg->type) {
default:
return 0;
case NID_sha1:
case NID_sha224:
case NID_sha256:
case NID_sha384:
case NID_sha512:
case NID_sha512_224:
case NID_sha512_256:
case NID_sha3_224:
case NID_sha3_256:
case NID_sha3_384:
case NID_sha3_512:
#ifndef FIPS_MODE
case NID_blake2b512:
case NID_blake2s256:
case NID_sm3:
#endif
break;
}
md = EVP_MD_fetch(drbg->libctx, ossl_prov_util_nid_to_name(drbg->type), "");
if (md == NULL)
return 0;
drbg->meth = &drbg_hmac_meth;
if (hmac->ctx == NULL) {
hmac->ctx = HMAC_CTX_new();
if (hmac->ctx == NULL) {
EVP_MD_meth_free(md);
return 0;
}
}
/* These are taken from SP 800-90 10.1 Table 2 */
EVP_MD_meth_free(hmac->md);
hmac->md = md;
hmac->blocklen = EVP_MD_size(md);
/* See SP800-57 Part1 Rev4 5.6.1 Table 3 */
drbg->strength = 64 * (int)(hmac->blocklen >> 3);
if (drbg->strength > 256)
drbg->strength = 256;
drbg->seedlen = hmac->blocklen;
drbg->min_entropylen = drbg->strength / 8;
drbg->max_entropylen = DRBG_MAX_LENGTH;
drbg->min_noncelen = drbg->min_entropylen / 2;
drbg->max_noncelen = DRBG_MAX_LENGTH;
drbg->max_perslen = DRBG_MAX_LENGTH;
drbg->max_adinlen = DRBG_MAX_LENGTH;
/* Maximum number of bits per request = 2^19 = 2^16 bytes*/
drbg->max_request = 1 << 16;
return 1;
}