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-rw-r--r--lib/crypto/c_src/bn.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/lib/crypto/c_src/bn.c b/lib/crypto/c_src/bn.c
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+++ b/lib/crypto/c_src/bn.c
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+/*
+ * %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)
+{
+ ErlNifBinary bin;
+ int sz;
+ if (!enif_inspect_binary(env,term,&bin)) {
+ return 0;
+ }
+ ERL_VALGRIND_ASSERT_MEM_DEFINED(bin.data, bin.size);
+ sz = bin.size - 4;
+ if (sz < 0 || get_int32(bin.data) != sz) {
+ return 0;
+ }
+ *bnp = BN_bin2bn(bin.data+4, sz, NULL);
+ return 1;
+}
+
+int get_bn_from_bin(ErlNifEnv* env, ERL_NIF_TERM term, BIGNUM** bnp)
+{
+ ErlNifBinary bin;
+ if (!enif_inspect_binary(env,term,&bin)) {
+ return 0;
+ }
+ ERL_VALGRIND_ASSERT_MEM_DEFINED(bin.data, bin.size);
+ *bnp = BN_bin2bn(bin.data, bin.size, NULL);
+ return 1;
+}
+
+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. */
+ bn_len = BN_num_bytes(bn);
+ bin_ptr = enif_make_new_binary(env, bn_len, &term);
+ BN_bn2bin(bn, bin_ptr);
+
+ return term;
+}
+
+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;
+ BN_CTX *bn_ctx;
+ unsigned char* ptr;
+ unsigned 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)
+ || !get_bn_from_bin(env, argv[1], &bn_exponent)
+ || !get_bn_from_bin(env, argv[2], &bn_modulo)
+ || !enif_get_uint(env,argv[3],&bin_hdr) || (bin_hdr & ~4)) {
+
+ if (bn_base) BN_free(bn_base);
+ if (bn_exponent) BN_free(bn_exponent);
+ if (bn_modulo) BN_free(bn_modulo);
+ return enif_make_badarg(env);
+ }
+ bn_result = BN_new();
+ bn_ctx = BN_CTX_new();
+ BN_mod_exp(bn_result, bn_base, bn_exponent, bn_modulo, bn_ctx);
+ dlen = BN_num_bytes(bn_result);
+ extra_byte = bin_hdr && BN_is_bit_set(bn_result, dlen*8-1);
+ ptr = enif_make_new_binary(env, bin_hdr+extra_byte+dlen, &ret);
+ if (bin_hdr) {
+ put_int32(ptr, extra_byte+dlen);
+ ptr[4] = 0; /* extra zeroed byte to ensure a positive mpint */
+ ptr += bin_hdr + extra_byte;
+ }
+ BN_bn2bin(bn_result, ptr);
+ BN_free(bn_result);
+ BN_CTX_free(bn_ctx);
+ BN_free(bn_modulo);
+ BN_free(bn_exponent);
+ BN_free(bn_base);
+ return ret;
+}
+
+#ifdef HAVE_EC
+ERL_NIF_TERM bn2term(ErlNifEnv* env, const BIGNUM *bn)
+{
+ unsigned dlen;
+ unsigned char* ptr;
+ ERL_NIF_TERM ret;
+
+ if (!bn)
+ return atom_undefined;
+
+ dlen = BN_num_bytes(bn);
+ ptr = enif_make_new_binary(env, dlen, &ret);
+ BN_bn2bin(bn, ptr);
+ ERL_VALGRIND_MAKE_MEM_DEFINED(ptr, dlen);
+ return ret;
+}
+#endif