| /** |
| * @file utils.c |
| * @author Mike Scott |
| * @author Kealan McCusker |
| * @date 28th July 2016 |
| * @brief AMCL Support functions for M-Pin servers |
| * |
| * LICENSE |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| /* AMCL Support functions for M-Pin servers */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include "amcl.h" |
| #include "utils.h" |
| |
| /* Decode a byte to a 2 chars string */ |
| |
| /** Decode hex value */ |
| void amcl_hex2bin(const char *src, char *dst, size_t src_len) |
| { |
| char v; |
| char c; |
| for (size_t i = 0; i < src_len/2; i++) |
| { |
| c = src[2*i]; |
| if (c >= '0' && c <= '9') |
| { |
| v = c - '0'; |
| } |
| else if (c >= 'A' && c <= 'F') |
| { |
| v = c - 'A' + 10; |
| } |
| else if (c >= 'a' && c <= 'f') |
| { |
| v = c - 'a' + 10; |
| } |
| else |
| { |
| v = 0; |
| } |
| v <<= 4; |
| c = src[2*i + 1]; |
| if (c >= '0' && c <= '9') |
| { |
| v += c - '0'; |
| } |
| else if (c >= 'A' && c <= 'F') |
| { |
| v += c - 'A' + 10; |
| } |
| else if (c >= 'a' && c <= 'f') |
| { |
| v += c - 'a' + 10; |
| } |
| else |
| { |
| v = 0; |
| } |
| dst[i] = v; |
| } |
| } |
| |
| /* Encode binary string */ |
| void amcl_bin2hex(const char *src, char *dst, size_t src_len, size_t dst_len) |
| { |
| const char * hexadecimals = "0123456789abcdef"; |
| unsigned char ch; |
| for (size_t i = 0; i < src_len && i< dst_len/2; i++) |
| { |
| ch=src[i]; |
| uint8_t res = ch / 16; |
| uint8_t mod = ch % 16; |
| dst[i*2] = hexadecimals[res]; |
| dst[(i*2)+1] = hexadecimals[mod]; |
| } |
| } |
| |
| /* Print encoded binary string in hex */ |
| void amcl_print_hex(const char *src, size_t src_len) |
| { |
| for (size_t i = 0; i < src_len; i++) |
| { |
| printf("%02x", (unsigned char) src[i]); |
| } |
| printf("\n"); |
| } |
| |
| /* Generates a random six digit one time password */ |
| int generateOTP(csprng* RNG) |
| { |
| int OTP=0; |
| |
| int val = 0; |
| unsigned char bytes[6] = {0}; |
| int mult=1; |
| |
| // Generate random 6 digit random value |
| for (int i=0; i<6; i++) |
| { |
| bytes[i]=(unsigned char)RAND_byte(RNG); |
| val = bytes[i]; |
| OTP = ((abs(val) % 10) * mult) + OTP; |
| mult = mult * 10; |
| } |
| |
| return OTP; |
| } |
| |
| /* Generate a random Octet */ |
| void generateRandom(csprng *RNG,octet *randomValue) |
| { |
| for (int i=0; i<randomValue->len; i++) |
| { |
| randomValue->val[i] = (char)RAND_byte(RNG); |
| } |
| } |