diff options
Diffstat (limited to 'openssl-1.1.0h/crypto/dh/dh_key.c')
| -rw-r--r-- | openssl-1.1.0h/crypto/dh/dh_key.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/dh/dh_key.c b/openssl-1.1.0h/crypto/dh/dh_key.c new file mode 100644 index 0000000..fce9ff4 --- /dev/null +++ b/openssl-1.1.0h/crypto/dh/dh_key.c @@ -0,0 +1,227 @@ +/* + * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the OpenSSL license (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 <stdio.h> +#include "internal/cryptlib.h" +#include "dh_locl.h" +#include "internal/bn_int.h" + +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) +{ + return dh->meth->generate_key(dh); +} + +int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) +{ + return dh->meth->compute_key(key, pub_key, dh); +} + +int DH_compute_key_padded(unsigned char *key, const BIGNUM *pub_key, DH *dh) +{ + int rv, pad; + rv = dh->meth->compute_key(key, pub_key, dh); + if (rv <= 0) + return rv; + pad = BN_num_bytes(dh->p) - rv; + if (pad > 0) { + memmove(key + pad, key, rv); + memset(key, 0, pad); + } + return rv + pad; +} + +static DH_METHOD dh_ossl = { + "OpenSSL DH Method", + generate_key, + compute_key, + dh_bn_mod_exp, + dh_init, + dh_finish, + DH_FLAG_FIPS_METHOD, + NULL, + NULL +}; + +static const DH_METHOD *default_DH_method = &dh_ossl; + +const DH_METHOD *DH_OpenSSL(void) +{ + return &dh_ossl; +} + +void DH_set_default_method(const DH_METHOD *meth) +{ + default_DH_method = meth; +} + +const DH_METHOD *DH_get_default_method(void) +{ + return default_DH_method; +} + +static int generate_key(DH *dh) +{ + int ok = 0; + int generate_new_key = 0; + unsigned l; + BN_CTX *ctx; + BN_MONT_CTX *mont = NULL; + BIGNUM *pub_key = NULL, *priv_key = NULL; + + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + + if (dh->priv_key == NULL) { + priv_key = BN_secure_new(); + if (priv_key == NULL) + goto err; + generate_new_key = 1; + } else + priv_key = dh->priv_key; + + if (dh->pub_key == NULL) { + pub_key = BN_new(); + if (pub_key == NULL) + goto err; + } 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_rand_range(priv_key, dh->q)) + goto err; + } + while (BN_is_zero(priv_key) || BN_is_one(priv_key)); + } else { + /* secret exponent length */ + l = dh->length ? dh->length : BN_num_bits(dh->p) - 1; + if (!BN_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY)) + 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_free(prk); + goto err; + } + /* We MUST free prk before any further use of priv_key */ + BN_free(prk); + } + + dh->pub_key = pub_key; + dh->priv_key = priv_key; + ok = 1; + err: + if (ok != 1) + DHerr(DH_F_GENERATE_KEY, ERR_R_BN_LIB); + + if (pub_key != dh->pub_key) + BN_free(pub_key); + if (priv_key != dh->priv_key) + BN_free(priv_key); + BN_CTX_free(ctx); + 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: + if (ctx != NULL) { + 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); +} |