From 3060e360980f3e80db1d903085d759338ab27f4a Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Sun, 26 Oct 2014 02:28:22 -0700 Subject: [PATCH] Add the RFC6979 PRNG --- src/Makefile.am | 2 ++ src/crypto/rfc6979_hmac_sha256.cpp | 47 ++++++++++++++++++++++++++++++ src/crypto/rfc6979_hmac_sha256.h | 36 +++++++++++++++++++++++ src/test/crypto_tests.cpp | 36 +++++++++++++++++++++++ 4 files changed, 121 insertions(+) create mode 100644 src/crypto/rfc6979_hmac_sha256.cpp create mode 100644 src/crypto/rfc6979_hmac_sha256.h diff --git a/src/Makefile.am b/src/Makefile.am index 1a5c57a3f..2863a7961 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -206,12 +206,14 @@ crypto_libbitcoin_crypto_a_SOURCES = \ crypto/sha256.cpp \ crypto/sha512.cpp \ crypto/hmac_sha256.cpp \ + crypto/rfc6979_hmac_sha256.cpp \ crypto/hmac_sha512.cpp \ crypto/ripemd160.cpp \ crypto/common.h \ crypto/sha256.h \ crypto/sha512.h \ crypto/hmac_sha256.h \ + crypto/rfc6979_hmac_sha256.h \ crypto/hmac_sha512.h \ crypto/sha1.h \ crypto/ripemd160.h diff --git a/src/crypto/rfc6979_hmac_sha256.cpp b/src/crypto/rfc6979_hmac_sha256.cpp new file mode 100644 index 000000000..3f935abfe --- /dev/null +++ b/src/crypto/rfc6979_hmac_sha256.cpp @@ -0,0 +1,47 @@ +// Copyright (c) 2014 The Bitcoin developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "crypto/rfc6979_hmac_sha256.h" + +#include + +#include + +static const unsigned char zero[1] = {0x00}; +static const unsigned char one[1] = {0x01}; + +RFC6979_HMAC_SHA256::RFC6979_HMAC_SHA256(const unsigned char* key, size_t keylen, const unsigned char* msg, size_t msglen) : retry(false) +{ + memset(V, 0x01, sizeof(V)); + memset(K, 0x00, sizeof(K)); + + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Write(zero, sizeof(zero)).Write(key, keylen).Write(msg, msglen).Finalize(K); + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Finalize(V); + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Write(one, sizeof(one)).Write(key, keylen).Write(msg, msglen).Finalize(K); + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Finalize(V); +} + +RFC6979_HMAC_SHA256::~RFC6979_HMAC_SHA256() +{ + memset(V, 0x01, sizeof(V)); + memset(K, 0x00, sizeof(K)); +} + +void RFC6979_HMAC_SHA256::Generate(unsigned char* output, size_t outputlen) +{ + if (retry) { + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Write(zero, sizeof(zero)).Finalize(K); + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Finalize(V); + } + + while (outputlen > 0) { + CHMAC_SHA256(K, sizeof(K)).Write(V, sizeof(V)).Finalize(V); + size_t len = std::min(outputlen, sizeof(V)); + memcpy(output, V, len); + output += len; + outputlen -= len; + } + + retry = true; +} diff --git a/src/crypto/rfc6979_hmac_sha256.h b/src/crypto/rfc6979_hmac_sha256.h new file mode 100644 index 000000000..e67ddcf8f --- /dev/null +++ b/src/crypto/rfc6979_hmac_sha256.h @@ -0,0 +1,36 @@ +// Copyright (c) 2014 The Bitcoin developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_RFC6979_HMAC_SHA256_H +#define BITCOIN_RFC6979_HMAC_SHA256_H + +#include "crypto/hmac_sha256.h" + +#include +#include + +/** The RFC 6979 PRNG using HMAC-SHA256. */ +class RFC6979_HMAC_SHA256 +{ +private: + unsigned char V[CHMAC_SHA256::OUTPUT_SIZE]; + unsigned char K[CHMAC_SHA256::OUTPUT_SIZE]; + bool retry; + +public: + /** + * Construct a new RFC6979 PRNG, using the given key and message. + * The message is assumed to be already hashed. + */ + RFC6979_HMAC_SHA256(const unsigned char* key, size_t keylen, const unsigned char* msg, size_t msglen); + + /** + * Generate a byte array. + */ + void Generate(unsigned char* output, size_t outputlen); + + ~RFC6979_HMAC_SHA256(); +}; + +#endif // BITCOIN_RFC6979_HMAC_SHA256_H diff --git a/src/test/crypto_tests.cpp b/src/test/crypto_tests.cpp index 466b38fca..26708f507 100644 --- a/src/test/crypto_tests.cpp +++ b/src/test/crypto_tests.cpp @@ -2,6 +2,7 @@ // Distributed under the MIT/X11 software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. +#include "crypto/rfc6979_hmac_sha256.h" #include "crypto/ripemd160.h" #include "crypto/sha1.h" #include "crypto/sha256.h" @@ -13,6 +14,7 @@ #include +#include #include BOOST_AUTO_TEST_SUITE(crypto_tests) @@ -246,4 +248,38 @@ BOOST_AUTO_TEST_CASE(hmac_sha512_testvectors) { "b6022cac3c4982b10d5eeb55c3e4de15134676fb6de0446065c97440fa8c6a58"); } +void TestRFC6979(const std::string& hexkey, const std::string& hexmsg, const std::vector& hexout) +{ + std::vector key = ParseHex(hexkey); + std::vector msg = ParseHex(hexmsg); + RFC6979_HMAC_SHA256 rng(&key[0], key.size(), &msg[0], msg.size()); + + for (unsigned int i = 0; i < hexout.size(); i++) { + std::vector out = ParseHex(hexout[i]); + std::vector gen; + gen.resize(out.size()); + rng.Generate(&gen[0], gen.size()); + BOOST_CHECK(out == gen); + } +} + +BOOST_AUTO_TEST_CASE(rfc6979_hmac_sha256) +{ + TestRFC6979( + "0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f00", + "4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a", + boost::assign::list_of + ("4fe29525b2086809159acdf0506efb86b0ec932c7ba44256ab321e421e67e9fb") + ("2bf0fff1d3c378a22dc5de1d856522325c65b504491a0cbd01cb8f3aa67ffd4a") + ("f528b410cb541f77000d7afb6c5b53c5c471eab43e466d9ac5190c39c82fd82e")); + + TestRFC6979( + "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF", + "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855", + boost::assign::list_of + ("9c236c165b82ae0cd590659e100b6bab3036e7ba8b06749baf6981e16f1a2b95") + ("df471061625bc0ea14b682feee2c9c02f235da04204c1d62a1536c6e17aed7a9") + ("7597887cbd76321f32e30440679a22cf7f8d9d2eac390e581fea091ce202ba94")); +} + BOOST_AUTO_TEST_SUITE_END()