1 // Copyright 2012 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #include "polo/util/poloutil.h" 16 17 #include <openssl/rand.h> 18 19 namespace polo { 20 namespace util { 21 22 const std::string PoloUtil::BytesToHexString(const uint8_t* bytes, 23 size_t length) { 24 // Use OpenSSL BigNum functions to perform the conversion. 25 BIGNUM* bn = BN_bin2bn(bytes, length, NULL); 26 char* hex = BN_bn2hex(bn); 27 std::string hex_string(hex); 28 BN_free(bn); 29 OPENSSL_free(hex); 30 return hex_string; 31 } 32 33 const size_t PoloUtil::HexStringToBytes(const std::string hex_string, 34 uint8_t*& bytes) { 35 // Use OpenSSL BigNum functions to perform the conversion. 36 BIGNUM* bn = NULL; 37 BN_hex2bn(&bn, hex_string.c_str()); 38 int length = BN_num_bytes(bn); 39 bytes = new uint8_t[length]; 40 BN_bn2bin(bn, &bytes[0]); 41 BN_free(bn); 42 return length; 43 } 44 45 const void PoloUtil::IntToBigEndianBytes(uint32_t value, 46 uint8_t*& bytes) { 47 // Use OpenSSL BigNum functions to perform the conversion. 48 BIGNUM* bn = BN_new(); 49 BN_add_word(bn, value); 50 51 // Initialize the array to 0 so there will be leading null bytes if the 52 // number is less than 4 bytes long. 53 bytes = new uint8_t[4]; 54 for (int i = 0; i < 4; i++) { 55 bytes[i] = 0; 56 } 57 58 int length = BN_num_bytes(bn); 59 BN_bn2bin(bn, &bytes[4 - length]); 60 BN_free(bn); 61 } 62 63 const uint32_t PoloUtil::BigEndianBytesToInt( 64 const uint8_t* bytes) { 65 // Use OpenSSL BigNum functions to perform the conversion. 66 BIGNUM* bn = BN_bin2bn(bytes, 4, NULL); 67 BN_ULONG value = bn->d[0]; 68 BN_free(bn); 69 return value; 70 } 71 72 uint8_t* PoloUtil::GenerateRandomBytes(size_t length) { 73 // Use the OpenSSL library to generate the random byte array. The RAND_bytes 74 // function is guaranteed to provide secure random bytes. 75 uint8_t* buffer = new uint8_t[length]; 76 if (RAND_bytes(buffer, length)) { 77 return buffer; 78 } else { 79 delete buffer; 80 return NULL; 81 } 82 } 83 84 } // namespace util 85 } // namespace polo 86
