diff options
Diffstat (limited to 'lib/crypto/c_src/bn.c')
| -rw-r--r-- | lib/crypto/c_src/bn.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/lib/crypto/c_src/bn.c b/lib/crypto/c_src/bn.c new file mode 100644 index 0000000000..6021d56db6 --- /dev/null +++ b/lib/crypto/c_src/bn.c @@ -0,0 +1,179 @@ +/* + * %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 "bn.h" + + +int get_bn_from_mpint(ErlNifEnv* env, ERL_NIF_TERM term, BIGNUM** bnp) +{ + BIGNUM *ret; + ErlNifBinary bin; + int sz; + + if (!enif_inspect_binary(env, term, &bin)) + goto err; + if (bin.size > INT_MAX - 4) + goto err; + + if (bin.size < 4) + goto err; + sz = (int)bin.size - 4; + if (get_int32(bin.data) != sz) + goto err; + + if ((ret = BN_bin2bn(bin.data+4, sz, NULL)) == NULL) + goto err; + + *bnp = ret; + return 1; + + err: + return 0; +} + +int get_bn_from_bin(ErlNifEnv* env, ERL_NIF_TERM term, BIGNUM** bnp) +{ + BIGNUM *ret; + ErlNifBinary bin; + + if (!enif_inspect_binary(env, term, &bin)) + goto err; + if (bin.size > INT_MAX) + goto err; + + if ((ret = BN_bin2bn(bin.data, (int)bin.size, NULL)) == NULL) + goto err; + + *bnp = ret; + return 1; + + err: + return 0; +} + +ERL_NIF_TERM bin_from_bn(ErlNifEnv* env, const BIGNUM *bn) +{ + int bn_len; + unsigned char *bin_ptr; + ERL_NIF_TERM term; + + /* Copy the bignum into an erlang binary. */ + if ((bn_len = BN_num_bytes(bn)) < 0) + goto err; + if ((bin_ptr = enif_make_new_binary(env, (size_t)bn_len, &term)) == NULL) + goto err; + + if (BN_bn2bin(bn, bin_ptr) < 0) + goto err; + + return term; + + err: + return atom_error; +} + +ERL_NIF_TERM mod_exp_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +{/* (Base,Exponent,Modulo,bin_hdr) */ + BIGNUM *bn_base = NULL, *bn_exponent = NULL, *bn_modulo = NULL, *bn_result = NULL; + BN_CTX *bn_ctx = NULL; + unsigned char* ptr; + int dlen; + unsigned bin_hdr; /* return type: 0=plain binary, 4: mpint */ + unsigned extra_byte; + ERL_NIF_TERM ret; + + if (!get_bn_from_bin(env, argv[0], &bn_base)) + goto bad_arg; + if (!get_bn_from_bin(env, argv[1], &bn_exponent)) + goto bad_arg; + if (!get_bn_from_bin(env, argv[2], &bn_modulo)) + goto bad_arg; + if (!enif_get_uint(env, argv[3], &bin_hdr)) + goto bad_arg; + if (bin_hdr != 0 && bin_hdr != 4) + goto bad_arg; + + if ((bn_result = BN_new()) == NULL) + goto err; + if ((bn_ctx = BN_CTX_new()) == NULL) + goto err; + + if (!BN_mod_exp(bn_result, bn_base, bn_exponent, bn_modulo, bn_ctx)) + goto err; + + dlen = BN_num_bytes(bn_result); + if (dlen < 0 || dlen > INT_MAX / 8) + goto bad_arg; + extra_byte = bin_hdr && BN_is_bit_set(bn_result, dlen * 8 - 1); + + if ((ptr = enif_make_new_binary(env, bin_hdr + extra_byte + (unsigned int)dlen, &ret)) == NULL) + goto err; + + if (bin_hdr) { + put_uint32(ptr, extra_byte + (unsigned int)dlen); + ptr[4] = 0; /* extra zeroed byte to ensure a positive mpint */ + ptr += bin_hdr + extra_byte; + } + + BN_bn2bin(bn_result, ptr); + goto done; + + bad_arg: + err: + ret = enif_make_badarg(env); + + done: + if (bn_base) + BN_free(bn_base); + if (bn_exponent) + BN_free(bn_exponent); + if (bn_modulo) + BN_free(bn_modulo); + if (bn_result) + BN_free(bn_result); + if (bn_ctx) + BN_CTX_free(bn_ctx); + return ret; +} + +#ifdef HAVE_EC +ERL_NIF_TERM bn2term(ErlNifEnv* env, const BIGNUM *bn) +{ + int dlen; + unsigned char* ptr; + ERL_NIF_TERM ret; + + if (bn == NULL) + return atom_undefined; + + dlen = BN_num_bytes(bn); + if (dlen < 0) + goto err; + if ((ptr = enif_make_new_binary(env, (size_t)dlen, &ret)) == NULL) + goto err; + + BN_bn2bin(bn, ptr); + + return ret; + + err: + return enif_make_badarg(env); +} +#endif |