1/* Copyright (c) 2015, Google Inc. 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15#include <string> 16#include <vector> 17 18#include <stdint.h> 19#include <stdio.h> 20#include <stdlib.h> 21 22#include <openssl/rand.h> 23 24#include "internal.h" 25 26 27static const struct argument kArguments[] = { 28 { 29 "-hex", kBooleanArgument, 30 "Hex encoded output." 31 }, 32 { 33 "", kOptionalArgument, "", 34 }, 35}; 36 37bool Rand(const std::vector<std::string> &args) { 38 bool forever = true, hex = false; 39 size_t len = 0; 40 41 if (!args.empty()) { 42 std::vector<std::string> args_copy(args); 43 const std::string &last_arg = args.back(); 44 45 if (!last_arg.empty() && last_arg[0] != '-') { 46 char *endptr; 47 unsigned long long num = strtoull(last_arg.c_str(), &endptr, 10); 48 if (*endptr == 0) { 49 len = num; 50 forever = false; 51 args_copy.pop_back(); 52 } 53 } 54 55 std::map<std::string, std::string> args_map; 56 if (!ParseKeyValueArguments(&args_map, args_copy, kArguments)) { 57 PrintUsage(kArguments); 58 return false; 59 } 60 61 hex = args_map.count("-hex") > 0; 62 } 63 64 uint8_t buf[4096]; 65 uint8_t hex_buf[8192]; 66 67 size_t done = 0; 68 while (forever || done < len) { 69 size_t todo = sizeof(buf); 70 if (!forever && todo > len - done) { 71 todo = len - done; 72 } 73 RAND_bytes(buf, todo); 74 if (hex) { 75 static const char hextable[16 + 1] = "0123456789abcdef"; 76 for (unsigned i = 0; i < todo; i++) { 77 hex_buf[i*2] = hextable[buf[i] >> 4]; 78 hex_buf[i*2 + 1] = hextable[buf[i] & 0xf]; 79 } 80 if (fwrite(hex_buf, todo*2, 1, stdout) != 1) { 81 return false; 82 } 83 } else { 84 if (fwrite(buf, todo, 1, stdout) != 1) { 85 return false; 86 } 87 } 88 done += todo; 89 } 90 91 if (hex && fwrite("\n", 1, 1, stdout) != 1) { 92 return false; 93 } 94 95 return true; 96} 97