diff options
Diffstat (limited to 'lib/crypto/c_src/dh.c')
| -rw-r--r-- | lib/crypto/c_src/dh.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/lib/crypto/c_src/dh.c b/lib/crypto/c_src/dh.c new file mode 100644 index 0000000000..0c18ad7a3f --- /dev/null +++ b/lib/crypto/c_src/dh.c @@ -0,0 +1,204 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2010-2018. All Rights Reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * %CopyrightEnd% + */ + +#include "dh.h" +#include "bn.h" + +ERL_NIF_TERM dh_generate_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (PrivKey|undefined, DHParams=[P,G], Mpint, Len|0) */ + DH *dh_params = NULL; + int mpint; /* 0 or 4 */ + + { + ERL_NIF_TERM head, tail; + BIGNUM + *dh_p = NULL, + *dh_g = NULL, + *priv_key_in = NULL; + unsigned long + len = 0; + + if (!(get_bn_from_bin(env, argv[0], &priv_key_in) + || argv[0] == atom_undefined) + || !enif_get_list_cell(env, argv[1], &head, &tail) + || !get_bn_from_bin(env, head, &dh_p) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &dh_g) + || !enif_is_empty_list(env, tail) + || !enif_get_int(env, argv[2], &mpint) || (mpint & ~4) + || !enif_get_ulong(env, argv[3], &len) + + /* Load dh_params with values to use by the generator. + Mem mgmnt transfered from dh_p etc to dh_params */ + || !(dh_params = DH_new()) + || (priv_key_in && !DH_set0_key(dh_params, NULL, priv_key_in)) + || !DH_set0_pqg(dh_params, dh_p, NULL, dh_g) + ) { + if (priv_key_in) BN_free(priv_key_in); + if (dh_p) BN_free(dh_p); + if (dh_g) BN_free(dh_g); + if (dh_params) DH_free(dh_params); + return enif_make_badarg(env); + } + + if (len) { + if (len < BN_num_bits(dh_p)) + DH_set_length(dh_params, len); + else { + if (priv_key_in) BN_free(priv_key_in); + if (dh_p) BN_free(dh_p); + if (dh_g) BN_free(dh_g); + if (dh_params) DH_free(dh_params); + return enif_make_badarg(env); + } + } + } + +#ifdef HAS_EVP_PKEY_CTX + { + EVP_PKEY_CTX *ctx; + EVP_PKEY *dhkey, *params; + int success; + + params = EVP_PKEY_new(); + success = EVP_PKEY_set1_DH(params, dh_params); /* set the key referenced by params to dh_params... */ + DH_free(dh_params); /* ...dh_params (and params) must be freed */ + if (!success) return atom_error; + + ctx = EVP_PKEY_CTX_new(params, NULL); + EVP_PKEY_free(params); + if (!ctx) { + return atom_error; + } + + if (!EVP_PKEY_keygen_init(ctx)) { + /* EVP_PKEY_CTX_free(ctx); */ + return atom_error; + } + + dhkey = EVP_PKEY_new(); + if (!EVP_PKEY_keygen(ctx, &dhkey)) { /* "performs a key generation operation, the ... */ + /*... generated key is written to ppkey." (=last arg) */ + /* EVP_PKEY_CTX_free(ctx); */ + /* EVP_PKEY_free(dhkey); */ + return atom_error; + } + + dh_params = EVP_PKEY_get1_DH(dhkey); /* return the referenced key. dh_params and dhkey must be freed */ + EVP_PKEY_free(dhkey); + if (!dh_params) { + /* EVP_PKEY_CTX_free(ctx); */ + return atom_error; + } + EVP_PKEY_CTX_free(ctx); + } +#else + if (!DH_generate_key(dh_params)) return atom_error; +#endif + { + unsigned char *pub_ptr, *prv_ptr; + int pub_len, prv_len; + ERL_NIF_TERM ret_pub, ret_prv; + const BIGNUM *pub_key_gen, *priv_key_gen; + + DH_get0_key(dh_params, + &pub_key_gen, &priv_key_gen); /* Get pub_key_gen and priv_key_gen. + "The values point to the internal representation of + the public key and private key values. This memory + should not be freed directly." says man */ + pub_len = BN_num_bytes(pub_key_gen); + prv_len = BN_num_bytes(priv_key_gen); + pub_ptr = enif_make_new_binary(env, pub_len+mpint, &ret_pub); + prv_ptr = enif_make_new_binary(env, prv_len+mpint, &ret_prv); + if (mpint) { + put_int32(pub_ptr, pub_len); pub_ptr += 4; + put_int32(prv_ptr, prv_len); prv_ptr += 4; + } + BN_bn2bin(pub_key_gen, pub_ptr); + BN_bn2bin(priv_key_gen, prv_ptr); + ERL_VALGRIND_MAKE_MEM_DEFINED(pub_ptr, pub_len); + ERL_VALGRIND_MAKE_MEM_DEFINED(prv_ptr, prv_len); + + DH_free(dh_params); + + return enif_make_tuple2(env, ret_pub, ret_prv); + } +} + +ERL_NIF_TERM dh_compute_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (OthersPublicKey, MyPrivateKey, DHParams=[P,G]) */ + BIGNUM *other_pub_key = NULL, + *dh_p = NULL, + *dh_g = NULL; + DH *dh_priv = DH_new(); + + /* Check the arguments and get + my private key (dh_priv), + the peer's public key (other_pub_key), + the parameters p & q + */ + + { + BIGNUM *dummy_pub_key = NULL, + *priv_key = NULL; + ERL_NIF_TERM head, tail; + + if (!get_bn_from_bin(env, argv[0], &other_pub_key) + || !get_bn_from_bin(env, argv[1], &priv_key) + || !enif_get_list_cell(env, argv[2], &head, &tail) + || !get_bn_from_bin(env, head, &dh_p) + || !enif_get_list_cell(env, tail, &head, &tail) + || !get_bn_from_bin(env, head, &dh_g) + || !enif_is_empty_list(env, tail) + + /* Note: DH_set0_key() does not allow setting only the + * private key, although DH_compute_key() does not use the + * public key. Work around this limitation by setting + * the public key to a copy of the private key. + */ + || !(dummy_pub_key = BN_dup(priv_key)) + || !DH_set0_key(dh_priv, dummy_pub_key, priv_key) + || !DH_set0_pqg(dh_priv, dh_p, NULL, dh_g) + ) { + if (dh_p) BN_free(dh_p); + if (dh_g) BN_free(dh_g); + if (other_pub_key) BN_free(other_pub_key); + if (dummy_pub_key) BN_free(dummy_pub_key); + if (priv_key) BN_free(priv_key); + return enif_make_badarg(env); + } + } + { + ErlNifBinary ret_bin; + int size; + + enif_alloc_binary(DH_size(dh_priv), &ret_bin); + size = DH_compute_key(ret_bin.data, other_pub_key, dh_priv); + BN_free(other_pub_key); + DH_free(dh_priv); + if (size<=0) { + enif_release_binary(&ret_bin); + return atom_error; + } + + if (size != ret_bin.size) enif_realloc_binary(&ret_bin, size); + return enif_make_binary(env, &ret_bin); + } +} |