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-rw-r--r--lib/crypto/c_src/bn.c186
1 files changed, 186 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..34ed4f7ebc
--- /dev/null
+++ b/lib/crypto/c_src/bn.c
@@ -0,0 +1,186 @@
+/*
+ * %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;
+
+ ERL_VALGRIND_ASSERT_MEM_DEFINED(bin.data, bin.size);
+
+ 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;
+
+ ERL_VALGRIND_ASSERT_MEM_DEFINED(bin.data, bin.size);
+
+ 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;
+
+ ASSERT(argc == 4);
+
+ 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);
+
+ ERL_VALGRIND_MAKE_MEM_DEFINED(ptr, dlen);
+ return ret;
+
+ err:
+ return enif_make_badarg(env);
+}
+#endif