/*
- * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2020 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
* https://www.openssl.org/source/license.html
*/
+/*
+ * DH low level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+
#include <stdio.h>
#include "internal/cryptlib.h"
-#include "dh_locl.h"
-#include "internal/bn_int.h"
+#include "dh_local.h"
+#include "crypto/bn.h"
+#include "crypto/dh.h"
+#include "crypto/security_bits.h"
+
+#ifdef FIPS_MODE
+# define MIN_STRENGTH 112
+#else
+# define MIN_STRENGTH 80
+#endif
static int generate_key(DH *dh);
-static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
static int dh_init(DH *dh);
static int dh_finish(DH *dh);
-int DH_generate_key(DH *dh)
+static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
{
- return dh->meth->generate_key(dh);
+ BN_CTX *ctx = NULL;
+ BN_MONT_CTX *mont = NULL;
+ BIGNUM *tmp;
+ int ret = -1;
+#ifndef FIPS_MODE
+ int check_result;
+#endif
+
+ if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(0, DH_R_MODULUS_TOO_LARGE);
+ goto err;
+ }
+
+ if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) {
+ DHerr(0, DH_R_MODULUS_TOO_SMALL);
+ return 0;
+ }
+
+ ctx = BN_CTX_new_ex(dh->libctx);
+ if (ctx == NULL)
+ goto err;
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+ if (tmp == NULL)
+ goto err;
+
+ if (dh->priv_key == NULL) {
+ DHerr(0, DH_R_NO_PRIVATE_VALUE);
+ goto err;
+ }
+
+ if (dh->flags & DH_FLAG_CACHE_MONT_P) {
+ mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
+ dh->lock, dh->params.p, ctx);
+ BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
+ if (!mont)
+ goto err;
+ }
+/* TODO(3.0) : Solve in a PR related to Key validation for DH */
+#ifndef FIPS_MODE
+ if (!DH_check_pub_key(dh, pub_key, &check_result) || check_result) {
+ DHerr(0, DH_R_INVALID_PUBKEY);
+ goto err;
+ }
+#endif
+ if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->params.p, ctx,
+ mont)) {
+ DHerr(0, ERR_R_BN_LIB);
+ goto err;
+ }
+
+ ret = BN_bn2bin(tmp, key);
+ err:
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ return ret;
}
int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
{
+#ifdef FIPS_MODE
+ return compute_key(key, pub_key, dh);
+#else
return dh->meth->compute_key(key, pub_key, dh);
+#endif
}
int DH_compute_key_padded(unsigned char *key, const BIGNUM *pub_key, DH *dh)
{
int rv, pad;
+
+#ifdef FIPS_MODE
+ rv = compute_key(key, pub_key, dh);
+#else
rv = dh->meth->compute_key(key, pub_key, dh);
+#endif
if (rv <= 0)
return rv;
- pad = BN_num_bytes(dh->p) - rv;
+ pad = BN_num_bytes(dh->params.p) - rv;
if (pad > 0) {
memmove(key + pad, key, rv);
memset(key, 0, pad);
return &dh_ossl;
}
+const DH_METHOD *DH_get_default_method(void)
+{
+ return default_DH_method;
+}
+
+static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
+ const BIGNUM *a, const BIGNUM *p,
+ const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
+{
+ return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+}
+
+static int dh_init(DH *dh)
+{
+ dh->flags |= DH_FLAG_CACHE_MONT_P;
+ ffc_params_init(&dh->params);
+ dh->dirty_cnt++;
+ return 1;
+}
+
+static int dh_finish(DH *dh)
+{
+ BN_MONT_CTX_free(dh->method_mont_p);
+ return 1;
+}
+
+#ifndef FIPS_MODE
void DH_set_default_method(const DH_METHOD *meth)
{
default_DH_method = meth;
}
+#endif /* FIPS_MODE */
-const DH_METHOD *DH_get_default_method(void)
+int DH_generate_key(DH *dh)
{
- return default_DH_method;
+#ifdef FIPS_MODE
+ return generate_key(dh);
+#else
+ return dh->meth->generate_key(dh);
+#endif
+}
+
+int dh_generate_public_key(BN_CTX *ctx, DH *dh, const BIGNUM *priv_key,
+ BIGNUM *pub_key)
+{
+ int ret = 0;
+ BIGNUM *prk = BN_new();
+ BN_MONT_CTX *mont = NULL;
+
+ if (prk == NULL)
+ return 0;
+
+ if (dh->flags & DH_FLAG_CACHE_MONT_P) {
+ mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
+ dh->lock, dh->params.p, ctx);
+ if (mont == NULL)
+ goto err;
+ }
+ BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
+
+ /* pub_key = g^priv_key mod p */
+ if (!dh->meth->bn_mod_exp(dh, pub_key, dh->params.g, prk, dh->params.p,
+ ctx, mont))
+ goto err;
+ ret = 1;
+err:
+ BN_clear_free(prk);
+ return ret;
}
static int generate_key(DH *dh)
{
int ok = 0;
int generate_new_key = 0;
+#ifndef FIPS_MODE
unsigned l;
+#endif
BN_CTX *ctx = NULL;
- BN_MONT_CTX *mont = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
- if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
- DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_LARGE);
+ if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(0, DH_R_MODULUS_TOO_LARGE);
+ return 0;
+ }
+
+ if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) {
+ DHerr(0, DH_R_MODULUS_TOO_SMALL);
return 0;
}
- ctx = BN_CTX_new();
+ ctx = BN_CTX_new_ex(dh->libctx);
if (ctx == NULL)
goto err;
if (priv_key == NULL)
goto err;
generate_new_key = 1;
- } else
+ } else {
priv_key = dh->priv_key;
+ }
if (dh->pub_key == NULL) {
pub_key = BN_new();
if (pub_key == NULL)
goto err;
- } else
+ } else {
pub_key = dh->pub_key;
-
- if (dh->flags & DH_FLAG_CACHE_MONT_P) {
- mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
- dh->lock, dh->p, ctx);
- if (!mont)
- goto err;
}
-
if (generate_new_key) {
- if (dh->q) {
- do {
- if (!BN_priv_rand_range(priv_key, dh->q))
- goto err;
- }
- while (BN_is_zero(priv_key) || BN_is_one(priv_key));
+ /* Is it an approved safe prime ?*/
+ if (DH_get_nid(dh) != NID_undef) {
+ int max_strength =
+ ifc_ffc_compute_security_bits(BN_num_bits(dh->params.p));
+
+ if (dh->params.q == NULL
+ || dh->length > BN_num_bits(dh->params.q))
+ goto err;
+ /* dh->length = maximum bit length of generated private key */
+ if (!ffc_generate_private_key(ctx, &dh->params, dh->length,
+ max_strength, priv_key))
+ goto err;
} else {
- /* secret exponent length */
- l = dh->length ? dh->length : BN_num_bits(dh->p) - 1;
- if (!BN_priv_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
+#ifdef FIPS_MODE
+ if (dh->params.q == NULL)
goto err;
- /*
- * We handle just one known case where g is a quadratic non-residue:
- * for g = 2: p % 8 == 3
- */
- if (BN_is_word(dh->g, DH_GENERATOR_2) && !BN_is_bit_set(dh->p, 2)) {
- /* clear bit 0, since it won't be a secret anyway */
- if (!BN_clear_bit(priv_key, 0))
+#else
+ if (dh->params.q == NULL) {
+ /* secret exponent length */
+ l = dh->length ? dh->length : BN_num_bits(dh->params.p) - 1;
+ if (!BN_priv_rand_ex(priv_key, l, BN_RAND_TOP_ONE,
+ BN_RAND_BOTTOM_ANY, ctx))
+ goto err;
+ /*
+ * We handle just one known case where g is a quadratic non-residue:
+ * for g = 2: p % 8 == 3
+ */
+ if (BN_is_word(dh->params.g, DH_GENERATOR_2)
+ && !BN_is_bit_set(dh->params.p, 2)) {
+ /* clear bit 0, since it won't be a secret anyway */
+ if (!BN_clear_bit(priv_key, 0))
+ goto err;
+ }
+ } else
+#endif
+ {
+ /*
+ * For FFC FIPS 186-4 keygen
+ * security strength s = 112,
+ * Max Private key size N = len(q)
+ */
+ if (!ffc_generate_private_key(ctx, &dh->params,
+ BN_num_bits(dh->params.q),
+ MIN_STRENGTH,
+ priv_key))
goto err;
}
}
}
- {
- BIGNUM *prk = BN_new();
-
- if (prk == NULL)
- goto err;
- BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
-
- if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) {
- BN_clear_free(prk);
- goto err;
- }
- /* We MUST free prk before any further use of priv_key */
- BN_clear_free(prk);
- }
+ if (!dh_generate_public_key(ctx, dh, priv_key, pub_key))
+ goto err;
dh->pub_key = pub_key;
dh->priv_key = priv_key;
+ dh->dirty_cnt++;
ok = 1;
err:
if (ok != 1)
- DHerr(DH_F_GENERATE_KEY, ERR_R_BN_LIB);
+ DHerr(0, ERR_R_BN_LIB);
if (pub_key != dh->pub_key)
BN_free(pub_key);
return ok;
}
-static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
-{
- BN_CTX *ctx = NULL;
- BN_MONT_CTX *mont = NULL;
- BIGNUM *tmp;
- int ret = -1;
- int check_result;
-
- if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
- DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_LARGE);
- goto err;
- }
-
- ctx = BN_CTX_new();
- if (ctx == NULL)
- goto err;
- BN_CTX_start(ctx);
- tmp = BN_CTX_get(ctx);
- if (tmp == NULL)
- goto err;
-
- if (dh->priv_key == NULL) {
- DHerr(DH_F_COMPUTE_KEY, DH_R_NO_PRIVATE_VALUE);
- goto err;
- }
-
- if (dh->flags & DH_FLAG_CACHE_MONT_P) {
- mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
- dh->lock, dh->p, ctx);
- BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
- if (!mont)
- goto err;
- }
-
- if (!DH_check_pub_key(dh, pub_key, &check_result) || check_result) {
- DHerr(DH_F_COMPUTE_KEY, DH_R_INVALID_PUBKEY);
- goto err;
- }
-
- if (!dh->
- meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->p, ctx, mont)) {
- DHerr(DH_F_COMPUTE_KEY, ERR_R_BN_LIB);
- goto err;
- }
-
- ret = BN_bn2bin(tmp, key);
- err:
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- return ret;
-}
-
-static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
- const BIGNUM *a, const BIGNUM *p,
- const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
-{
- return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
-}
-
-static int dh_init(DH *dh)
-{
- dh->flags |= DH_FLAG_CACHE_MONT_P;
- return 1;
-}
-
-static int dh_finish(DH *dh)
-{
- BN_MONT_CTX_free(dh->method_mont_p);
- return 1;
-}
-
int dh_buf2key(DH *dh, const unsigned char *buf, size_t len)
{
int err_reason = DH_R_BN_ERROR;
projects / openssl.git / blobdiff