From 7bd0ebb1abd1df5a13fa909256d8131d2335f915 Mon Sep 17 00:00:00 2001 From: stelar7 Date: Sun, 10 Apr 2022 13:39:56 +0200 Subject: [PATCH] LibCrypto: Add ChaCha20 --- Tests/LibCrypto/CMakeLists.txt | 1 + Tests/LibCrypto/TestChaCha20.cpp | 141 +++++++++++++++ Userland/Libraries/LibCrypto/CMakeLists.txt | 1 + .../Libraries/LibCrypto/Cipher/ChaCha20.cpp | 160 ++++++++++++++++++ .../Libraries/LibCrypto/Cipher/ChaCha20.h | 31 ++++ 5 files changed, 334 insertions(+) create mode 100644 Tests/LibCrypto/TestChaCha20.cpp create mode 100644 Userland/Libraries/LibCrypto/Cipher/ChaCha20.cpp create mode 100644 Userland/Libraries/LibCrypto/Cipher/ChaCha20.h diff --git a/Tests/LibCrypto/CMakeLists.txt b/Tests/LibCrypto/CMakeLists.txt index 253ec16df0..41e62e1c9c 100644 --- a/Tests/LibCrypto/CMakeLists.txt +++ b/Tests/LibCrypto/CMakeLists.txt @@ -2,6 +2,7 @@ set(TEST_SOURCES TestAES.cpp TestBigInteger.cpp TestChecksum.cpp + TestChaCha20.cpp TestCurves.cpp TestHash.cpp TestHMAC.cpp diff --git a/Tests/LibCrypto/TestChaCha20.cpp b/Tests/LibCrypto/TestChaCha20.cpp new file mode 100644 index 0000000000..618bfc30bf --- /dev/null +++ b/Tests/LibCrypto/TestChaCha20.cpp @@ -0,0 +1,141 @@ +/* + * Copyright (c) 2022, stelar7 + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include +#include +#include + +// https://datatracker.ietf.org/doc/html/rfc7539#appendix-A.2 +TEST_CASE(test_vector_1) +{ + u8 key[32] = {}; + u8 nonce[12] = {}; + u32 initial_block_counter = {}; + u8 plaintext[64] = {}; + u8 ciphertext[64] { + 0x76, 0xb8, 0xe0, 0xad, 0xa0, 0xf1, 0x3d, 0x90, 0x40, 0x5d, 0x6a, 0xe5, 0x53, 0x86, 0xbd, 0x28, + 0xbd, 0xd2, 0x19, 0xb8, 0xa0, 0x8d, 0xed, 0x1a, 0xa8, 0x36, 0xef, 0xcc, 0x8b, 0x77, 0x0d, 0xc7, + 0xda, 0x41, 0x59, 0x7c, 0x51, 0x57, 0x48, 0x8d, 0x77, 0x24, 0xe0, 0x3f, 0xb8, 0xd8, 0x4a, 0x37, + 0x6a, 0x43, 0xb8, 0xf4, 0x15, 0x18, 0xa1, 0x1c, 0xc3, 0x87, 0xb6, 0x69, 0xb2, 0xee, 0x65, 0x86 + }; + + auto result = MUST(ByteBuffer::create_uninitialized(64)); + auto output = result.bytes(); + Crypto::Cipher::ChaCha20 cipher(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 }, initial_block_counter); + cipher.encrypt(ReadonlyBytes { plaintext, 64 }, output); + auto expected = ReadonlyBytes { ciphertext, 64 }; + EXPECT_EQ(result, expected); +} + +TEST_CASE(test_vector_2) +{ + u8 key[32] { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 + }; + u8 nonce[12] { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 + }; + u32 initial_block_counter { 1 }; + u8 plaintext[375] { + 0x41, 0x6e, 0x79, 0x20, 0x73, 0x75, 0x62, 0x6d, 0x69, 0x73, 0x73, 0x69, 0x6f, 0x6e, 0x20, 0x74, + 0x6f, 0x20, 0x74, 0x68, 0x65, 0x20, 0x49, 0x45, 0x54, 0x46, 0x20, 0x69, 0x6e, 0x74, 0x65, 0x6e, + 0x64, 0x65, 0x64, 0x20, 0x62, 0x79, 0x20, 0x74, 0x68, 0x65, 0x20, 0x43, 0x6f, 0x6e, 0x74, 0x72, + 0x69, 0x62, 0x75, 0x74, 0x6f, 0x72, 0x20, 0x66, 0x6f, 0x72, 0x20, 0x70, 0x75, 0x62, 0x6c, 0x69, + 0x63, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x20, 0x61, 0x73, 0x20, 0x61, 0x6c, 0x6c, 0x20, 0x6f, 0x72, + 0x20, 0x70, 0x61, 0x72, 0x74, 0x20, 0x6f, 0x66, 0x20, 0x61, 0x6e, 0x20, 0x49, 0x45, 0x54, 0x46, + 0x20, 0x49, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2d, 0x44, 0x72, 0x61, 0x66, 0x74, 0x20, + 0x6f, 0x72, 0x20, 0x52, 0x46, 0x43, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x61, 0x6e, 0x79, 0x20, 0x73, + 0x74, 0x61, 0x74, 0x65, 0x6d, 0x65, 0x6e, 0x74, 0x20, 0x6d, 0x61, 0x64, 0x65, 0x20, 0x77, 0x69, + 0x74, 0x68, 0x69, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6f, 0x6e, 0x74, 0x65, 0x78, 0x74, + 0x20, 0x6f, 0x66, 0x20, 0x61, 0x6e, 0x20, 0x49, 0x45, 0x54, 0x46, 0x20, 0x61, 0x63, 0x74, 0x69, + 0x76, 0x69, 0x74, 0x79, 0x20, 0x69, 0x73, 0x20, 0x63, 0x6f, 0x6e, 0x73, 0x69, 0x64, 0x65, 0x72, + 0x65, 0x64, 0x20, 0x61, 0x6e, 0x20, 0x22, 0x49, 0x45, 0x54, 0x46, 0x20, 0x43, 0x6f, 0x6e, 0x74, + 0x72, 0x69, 0x62, 0x75, 0x74, 0x69, 0x6f, 0x6e, 0x22, 0x2e, 0x20, 0x53, 0x75, 0x63, 0x68, 0x20, + 0x73, 0x74, 0x61, 0x74, 0x65, 0x6d, 0x65, 0x6e, 0x74, 0x73, 0x20, 0x69, 0x6e, 0x63, 0x6c, 0x75, + 0x64, 0x65, 0x20, 0x6f, 0x72, 0x61, 0x6c, 0x20, 0x73, 0x74, 0x61, 0x74, 0x65, 0x6d, 0x65, 0x6e, + 0x74, 0x73, 0x20, 0x69, 0x6e, 0x20, 0x49, 0x45, 0x54, 0x46, 0x20, 0x73, 0x65, 0x73, 0x73, 0x69, + 0x6f, 0x6e, 0x73, 0x2c, 0x20, 0x61, 0x73, 0x20, 0x77, 0x65, 0x6c, 0x6c, 0x20, 0x61, 0x73, 0x20, + 0x77, 0x72, 0x69, 0x74, 0x74, 0x65, 0x6e, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x65, 0x6c, 0x65, 0x63, + 0x74, 0x72, 0x6f, 0x6e, 0x69, 0x63, 0x20, 0x63, 0x6f, 0x6d, 0x6d, 0x75, 0x6e, 0x69, 0x63, 0x61, + 0x74, 0x69, 0x6f, 0x6e, 0x73, 0x20, 0x6d, 0x61, 0x64, 0x65, 0x20, 0x61, 0x74, 0x20, 0x61, 0x6e, + 0x79, 0x20, 0x74, 0x69, 0x6d, 0x65, 0x20, 0x6f, 0x72, 0x20, 0x70, 0x6c, 0x61, 0x63, 0x65, 0x2c, + 0x20, 0x77, 0x68, 0x69, 0x63, 0x68, 0x20, 0x61, 0x72, 0x65, 0x20, 0x61, 0x64, 0x64, 0x72, 0x65, + 0x73, 0x73, 0x65, 0x64, 0x20, 0x74, 0x6f + }; + u8 ciphertext[375] { + 0xa3, 0xfb, 0xf0, 0x7d, 0xf3, 0xfa, 0x2f, 0xde, 0x4f, 0x37, 0x6c, 0xa2, 0x3e, 0x82, 0x73, 0x70, + 0x41, 0x60, 0x5d, 0x9f, 0x4f, 0x4f, 0x57, 0xbd, 0x8c, 0xff, 0x2c, 0x1d, 0x4b, 0x79, 0x55, 0xec, + 0x2a, 0x97, 0x94, 0x8b, 0xd3, 0x72, 0x29, 0x15, 0xc8, 0xf3, 0xd3, 0x37, 0xf7, 0xd3, 0x70, 0x05, + 0x0e, 0x9e, 0x96, 0xd6, 0x47, 0xb7, 0xc3, 0x9f, 0x56, 0xe0, 0x31, 0xca, 0x5e, 0xb6, 0x25, 0x0d, + 0x40, 0x42, 0xe0, 0x27, 0x85, 0xec, 0xec, 0xfa, 0x4b, 0x4b, 0xb5, 0xe8, 0xea, 0xd0, 0x44, 0x0e, + 0x20, 0xb6, 0xe8, 0xdb, 0x09, 0xd8, 0x81, 0xa7, 0xc6, 0x13, 0x2f, 0x42, 0x0e, 0x52, 0x79, 0x50, + 0x42, 0xbd, 0xfa, 0x77, 0x73, 0xd8, 0xa9, 0x05, 0x14, 0x47, 0xb3, 0x29, 0x1c, 0xe1, 0x41, 0x1c, + 0x68, 0x04, 0x65, 0x55, 0x2a, 0xa6, 0xc4, 0x05, 0xb7, 0x76, 0x4d, 0x5e, 0x87, 0xbe, 0xa8, 0x5a, + 0xd0, 0x0f, 0x84, 0x49, 0xed, 0x8f, 0x72, 0xd0, 0xd6, 0x62, 0xab, 0x05, 0x26, 0x91, 0xca, 0x66, + 0x42, 0x4b, 0xc8, 0x6d, 0x2d, 0xf8, 0x0e, 0xa4, 0x1f, 0x43, 0xab, 0xf9, 0x37, 0xd3, 0x25, 0x9d, + 0xc4, 0xb2, 0xd0, 0xdf, 0xb4, 0x8a, 0x6c, 0x91, 0x39, 0xdd, 0xd7, 0xf7, 0x69, 0x66, 0xe9, 0x28, + 0xe6, 0x35, 0x55, 0x3b, 0xa7, 0x6c, 0x5c, 0x87, 0x9d, 0x7b, 0x35, 0xd4, 0x9e, 0xb2, 0xe6, 0x2b, + 0x08, 0x71, 0xcd, 0xac, 0x63, 0x89, 0x39, 0xe2, 0x5e, 0x8a, 0x1e, 0x0e, 0xf9, 0xd5, 0x28, 0x0f, + 0xa8, 0xca, 0x32, 0x8b, 0x35, 0x1c, 0x3c, 0x76, 0x59, 0x89, 0xcb, 0xcf, 0x3d, 0xaa, 0x8b, 0x6c, + 0xcc, 0x3a, 0xaf, 0x9f, 0x39, 0x79, 0xc9, 0x2b, 0x37, 0x20, 0xfc, 0x88, 0xdc, 0x95, 0xed, 0x84, + 0xa1, 0xbe, 0x05, 0x9c, 0x64, 0x99, 0xb9, 0xfd, 0xa2, 0x36, 0xe7, 0xe8, 0x18, 0xb0, 0x4b, 0x0b, + 0xc3, 0x9c, 0x1e, 0x87, 0x6b, 0x19, 0x3b, 0xfe, 0x55, 0x69, 0x75, 0x3f, 0x88, 0x12, 0x8c, 0xc0, + 0x8a, 0xaa, 0x9b, 0x63, 0xd1, 0xa1, 0x6f, 0x80, 0xef, 0x25, 0x54, 0xd7, 0x18, 0x9c, 0x41, 0x1f, + 0x58, 0x69, 0xca, 0x52, 0xc5, 0xb8, 0x3f, 0xa3, 0x6f, 0xf2, 0x16, 0xb9, 0xc1, 0xd3, 0x00, 0x62, + 0xbe, 0xbc, 0xfd, 0x2d, 0xc5, 0xbc, 0xe0, 0x91, 0x19, 0x34, 0xfd, 0xa7, 0x9a, 0x86, 0xf6, 0xe6, + 0x98, 0xce, 0xd7, 0x59, 0xc3, 0xff, 0x9b, 0x64, 0x77, 0x33, 0x8f, 0x3d, 0xa4, 0xf9, 0xcd, 0x85, + 0x14, 0xea, 0x99, 0x82, 0xcc, 0xaf, 0xb3, 0x41, 0xb2, 0x38, 0x4d, 0xd9, 0x02, 0xf3, 0xd1, 0xab, + 0x7a, 0xc6, 0x1d, 0xd2, 0x9c, 0x6f, 0x21, 0xba, 0x5b, 0x86, 0x2f, 0x37, 0x30, 0xe3, 0x7c, 0xfd, + 0xc4, 0xfd, 0x80, 0x6c, 0x22, 0xf2, 0x21 + }; + + auto result = MUST(ByteBuffer::create_uninitialized(375)); + auto output = result.bytes(); + Crypto::Cipher::ChaCha20 cipher(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 }, initial_block_counter); + cipher.encrypt(ReadonlyBytes { plaintext, 375 }, output); + auto expected = ReadonlyBytes { ciphertext, 375 }; + EXPECT_EQ(result, expected); +} + +TEST_CASE(test_vector_3) +{ + u8 key[32] { + 0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0, + 0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0 + }; + u8 nonce[12] { + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2 + }; + u32 initial_block_counter { 42 }; + u8 plaintext[127] { + 0x27, 0x54, 0x77, 0x61, 0x73, 0x20, 0x62, 0x72, 0x69, 0x6c, 0x6c, 0x69, 0x67, 0x2c, 0x20, 0x61, + 0x6e, 0x64, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, 0x6c, 0x69, 0x74, 0x68, 0x79, 0x20, 0x74, 0x6f, + 0x76, 0x65, 0x73, 0x0a, 0x44, 0x69, 0x64, 0x20, 0x67, 0x79, 0x72, 0x65, 0x20, 0x61, 0x6e, 0x64, + 0x20, 0x67, 0x69, 0x6d, 0x62, 0x6c, 0x65, 0x20, 0x69, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x77, + 0x61, 0x62, 0x65, 0x3a, 0x0a, 0x41, 0x6c, 0x6c, 0x20, 0x6d, 0x69, 0x6d, 0x73, 0x79, 0x20, 0x77, + 0x65, 0x72, 0x65, 0x20, 0x74, 0x68, 0x65, 0x20, 0x62, 0x6f, 0x72, 0x6f, 0x67, 0x6f, 0x76, 0x65, + 0x73, 0x2c, 0x0a, 0x41, 0x6e, 0x64, 0x20, 0x74, 0x68, 0x65, 0x20, 0x6d, 0x6f, 0x6d, 0x65, 0x20, + 0x72, 0x61, 0x74, 0x68, 0x73, 0x20, 0x6f, 0x75, 0x74, 0x67, 0x72, 0x61, 0x62, 0x65, 0x2e + }; + u8 ciphertext[127] { + 0x62, 0xe6, 0x34, 0x7f, 0x95, 0xed, 0x87, 0xa4, 0x5f, 0xfa, 0xe7, 0x42, 0x6f, 0x27, 0xa1, 0xdf, + 0x5f, 0xb6, 0x91, 0x10, 0x04, 0x4c, 0x0d, 0x73, 0x11, 0x8e, 0xff, 0xa9, 0x5b, 0x01, 0xe5, 0xcf, + 0x16, 0x6d, 0x3d, 0xf2, 0xd7, 0x21, 0xca, 0xf9, 0xb2, 0x1e, 0x5f, 0xb1, 0x4c, 0x61, 0x68, 0x71, + 0xfd, 0x84, 0xc5, 0x4f, 0x9d, 0x65, 0xb2, 0x83, 0x19, 0x6c, 0x7f, 0xe4, 0xf6, 0x05, 0x53, 0xeb, + 0xf3, 0x9c, 0x64, 0x02, 0xc4, 0x22, 0x34, 0xe3, 0x2a, 0x35, 0x6b, 0x3e, 0x76, 0x43, 0x12, 0xa6, + 0x1a, 0x55, 0x32, 0x05, 0x57, 0x16, 0xea, 0xd6, 0x96, 0x25, 0x68, 0xf8, 0x7d, 0x3f, 0x3f, 0x77, + 0x04, 0xc6, 0xa8, 0xd1, 0xbc, 0xd1, 0xbf, 0x4d, 0x50, 0xd6, 0x15, 0x4b, 0x6d, 0xa7, 0x31, 0xb1, + 0x87, 0xb5, 0x8d, 0xfd, 0x72, 0x8a, 0xfa, 0x36, 0x75, 0x7a, 0x79, 0x7a, 0xc1, 0x88, 0xd1 + }; + + auto result = MUST(ByteBuffer::create_uninitialized(127)); + auto output = result.bytes(); + Crypto::Cipher::ChaCha20 cipher(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 }, initial_block_counter); + cipher.encrypt(ReadonlyBytes { plaintext, 127 }, output); + auto expected = ReadonlyBytes { ciphertext, 127 }; + EXPECT_EQ(result, expected); +} diff --git a/Userland/Libraries/LibCrypto/CMakeLists.txt b/Userland/Libraries/LibCrypto/CMakeLists.txt index a62e63db81..f4bac6ab12 100644 --- a/Userland/Libraries/LibCrypto/CMakeLists.txt +++ b/Userland/Libraries/LibCrypto/CMakeLists.txt @@ -18,6 +18,7 @@ set(SOURCES Checksum/Adler32.cpp Checksum/CRC32.cpp Cipher/AES.cpp + Cipher/ChaCha20.cpp Curves/SECP256r1.cpp Curves/X25519.cpp Curves/X448.cpp diff --git a/Userland/Libraries/LibCrypto/Cipher/ChaCha20.cpp b/Userland/Libraries/LibCrypto/Cipher/ChaCha20.cpp new file mode 100644 index 0000000000..d7433ab300 --- /dev/null +++ b/Userland/Libraries/LibCrypto/Cipher/ChaCha20.cpp @@ -0,0 +1,160 @@ +/* + * Copyright (c) 2022, stelar7 + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include +#include +#include + +namespace Crypto::Cipher { + +ChaCha20::ChaCha20(ReadonlyBytes key, ReadonlyBytes nonce, u32 initial_counter) +{ + VERIFY(key.size() == 16 || key.size() == 32); + VERIFY(nonce.size() == 8 || nonce.size() == 12); + + // The first four words (0-3) are constants + if (key.size() == 32) { + m_state[0] = CONSTANT_32_BYTES[0]; + m_state[1] = CONSTANT_32_BYTES[1]; + m_state[2] = CONSTANT_32_BYTES[2]; + m_state[3] = CONSTANT_32_BYTES[3]; + } else { + m_state[0] = CONSTANT_16_BYTES[0]; + m_state[1] = CONSTANT_16_BYTES[1]; + m_state[2] = CONSTANT_16_BYTES[2]; + m_state[3] = CONSTANT_16_BYTES[3]; + } + + // The next eight words (4-11) are taken from the key by reading the bytes in little-endian order, in 4-byte chunks. + for (u32 i = 0; i < 16; i += 4) { + m_state[(i / 4) + 4] = AK::convert_between_host_and_little_endian(ByteReader::load32(key.offset(i))); + } + + // NOTE: For the 128-bit keys we read the same bytes twice to fill the state + u32 key_offset = key.size() == 32 ? 16 : 0; + for (u32 i = 0; i < 16; i += 4) { + m_state[(i / 4) + 8] = AK::convert_between_host_and_little_endian(ByteReader::load32(key.offset(key_offset + i))); + } + + // Word 12 is a block counter. Since each block is 64-bytes, a 32-bit word is enough for 256 gigabytes of data. + m_state[12] = initial_counter; + + // Words 13-15 are a nonce, which should not be repeated for the same key. + // The 13th word is the first 32 bits of the input nonce taken as a little-endian integer, + // while the 15th word is the last 32 bits. + + // NOTE: In the case of an 8-byte nonce, we skip the 13th word + u32 nonce_offset = nonce.size() == 8 ? 1 : 0; + for (u32 i = 0; i < 12; i += 4) { + m_state[(i / 4) + 13 + nonce_offset] = AK::convert_between_host_and_little_endian(ByteReader::load32(nonce.offset(i))); + } +} + +// https://datatracker.ietf.org/doc/html/rfc7539#section-2.3 +void ChaCha20::generate_block() +{ + // Copy the current state into the block + memcpy(m_block, m_state, 16 * sizeof(u32)); + + // ChaCha20 runs 20 rounds, alternating between "column rounds" and "diagonal rounds". + // Each round consists of four quarter-rounds + for (u32 i = 0; i < 20; i += 2) { + // Column rounds + do_quarter_round(m_block[0], m_block[4], m_block[8], m_block[12]); + do_quarter_round(m_block[1], m_block[5], m_block[9], m_block[13]); + do_quarter_round(m_block[2], m_block[6], m_block[10], m_block[14]); + do_quarter_round(m_block[3], m_block[7], m_block[11], m_block[15]); + + // Diagonal rounds + do_quarter_round(m_block[0], m_block[5], m_block[10], m_block[15]); + do_quarter_round(m_block[1], m_block[6], m_block[11], m_block[12]); + do_quarter_round(m_block[2], m_block[7], m_block[8], m_block[13]); + do_quarter_round(m_block[3], m_block[4], m_block[9], m_block[14]); + } + + // At the end of 20 rounds, we add the original input words to the output words, + for (u32 i = 0; i < 16; i++) { + m_block[i] += m_state[i]; + } + + // and serialize the result by sequencing the words one-by-one in little-endian order. + for (u32 i = 0; i < 16; i++) { + m_block[i] = AK::convert_between_host_and_little_endian(m_block[i]); + } +} + +ALWAYS_INLINE static void rotl(u32& x, u32 n) +{ + x = (x << n) | (x >> (32 - n)); +} + +// https://datatracker.ietf.org/doc/html/rfc8439#section-2.1 +void ChaCha20::do_quarter_round(u32& a, u32& b, u32& c, u32& d) +{ + a += b; + d ^= a; + rotl(d, 16); + + c += d; + b ^= c; + rotl(b, 12); + + a += b; + d ^= a; + rotl(d, 8); + + c += d; + b ^= c; + rotl(b, 7); +} + +void ChaCha20::run_cipher(ReadonlyBytes input, Bytes& output) +{ + size_t offset = 0; + size_t block_offset = 0; + while (offset < input.size()) { + if (block_offset == 0 || block_offset >= 64) { + // Generate a new XOR block + generate_block(); + + // Increment the block counter, and carry over to block 13 + m_state[12]++; + if (m_state[12] == 0) { + m_state[13]++; + } + + block_offset = 0; + } + + // XOR the input and the current block + u32 n = min(input.size() - offset, 64 - block_offset); + u8* key_block = (u8*)m_block + block_offset; + for (u32 i = 0; i < n; i++) { + u8 input_byte = input.offset_pointer(offset)[i]; + u8 key_byte = key_block[i]; + u8 output_byte = input_byte ^ key_byte; + + ByteReader::store(output.offset_pointer(offset + i), output_byte); + } + + offset += n; + block_offset += n; + } +} + +void ChaCha20::encrypt(ReadonlyBytes input, Bytes& output) +{ + VERIFY(input.size() <= output.size()); + this->run_cipher(input, output); +} + +void ChaCha20::decrypt(ReadonlyBytes input, Bytes& output) +{ + VERIFY(input.size() <= output.size()); + this->run_cipher(input, output); +} + +} diff --git a/Userland/Libraries/LibCrypto/Cipher/ChaCha20.h b/Userland/Libraries/LibCrypto/Cipher/ChaCha20.h new file mode 100644 index 0000000000..74cf573575 --- /dev/null +++ b/Userland/Libraries/LibCrypto/Cipher/ChaCha20.h @@ -0,0 +1,31 @@ +/* + * Copyright (c) 2022, stelar7 + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#pragma once + +#include + +namespace Crypto::Cipher { + +class ChaCha20 { + static constexpr u32 CONSTANT_16_BYTES[] { 0x61707865, 0x3120646E, 0x79622D36, 0x6B206574 }; + static constexpr u32 CONSTANT_32_BYTES[] { 0x61707865, 0x3320646E, 0x79622D32, 0x6B206574 }; + +public: + ChaCha20(ReadonlyBytes key, ReadonlyBytes nonce, u32 initial_counter = 0); + + void encrypt(ReadonlyBytes input, Bytes& output); + void decrypt(ReadonlyBytes input, Bytes& output); + +private: + void run_cipher(ReadonlyBytes input, Bytes& output); + void generate_block(); + ALWAYS_INLINE void do_quarter_round(u32& a, u32& b, u32& c, u32& d); + + u32 m_state[16] {}; + u32 m_block[16] {}; +}; +}