diff --git a/cipher/chacha20.c b/cipher/chacha20.c index eae4979c..48fff625 100644 --- a/cipher/chacha20.c +++ b/cipher/chacha20.c @@ -1,979 +1,979 @@ /* chacha20.c - Bernstein's ChaCha20 cipher * Copyright (C) 2014,2017-2019 Jussi Kivilinna * * This file is part of Libgcrypt. * * Libgcrypt is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser general Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * Libgcrypt is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see . * * For a description of the algorithm, see: * http://cr.yp.to/chacha.html */ /* * Based on D. J. Bernstein reference implementation at * http://cr.yp.to/chacha.html: * * chacha-regs.c version 20080118 * D. J. Bernstein * Public domain. */ #include #include #include #include #include "types.h" #include "g10lib.h" #include "cipher.h" #include "cipher-internal.h" #include "bufhelp.h" #define CHACHA20_MIN_KEY_SIZE 16 /* Bytes. */ #define CHACHA20_MAX_KEY_SIZE 32 /* Bytes. */ #define CHACHA20_BLOCK_SIZE 64 /* Bytes. */ #define CHACHA20_MIN_IV_SIZE 8 /* Bytes. */ #define CHACHA20_MAX_IV_SIZE 12 /* Bytes. */ #define CHACHA20_CTR_SIZE 16 /* Bytes. */ /* USE_SSSE3 indicates whether to compile with Intel SSSE3 code. */ #undef USE_SSSE3 #if defined(__x86_64__) && defined(HAVE_GCC_INLINE_ASM_SSSE3) && \ (defined(HAVE_COMPATIBLE_GCC_AMD64_PLATFORM_AS) || \ defined(HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS)) # define USE_SSSE3 1 #endif /* USE_AVX2 indicates whether to compile with Intel AVX2 code. */ #undef USE_AVX2 #if defined(__x86_64__) && defined(HAVE_GCC_INLINE_ASM_AVX2) && \ (defined(HAVE_COMPATIBLE_GCC_AMD64_PLATFORM_AS) || \ defined(HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS)) # define USE_AVX2 1 #endif /* USE_ARMV7_NEON indicates whether to enable ARMv7 NEON assembly code. */ #undef USE_ARMV7_NEON #ifdef ENABLE_NEON_SUPPORT # if defined(HAVE_ARM_ARCH_V6) && defined(__ARMEL__) \ && defined(HAVE_COMPATIBLE_GCC_ARM_PLATFORM_AS) \ && defined(HAVE_GCC_INLINE_ASM_NEON) # define USE_ARMV7_NEON 1 # endif #endif /* USE_AARCH64_SIMD indicates whether to enable ARMv8 SIMD assembly * code. */ #undef USE_AARCH64_SIMD #ifdef ENABLE_NEON_SUPPORT # if defined(__AARCH64EL__) \ && defined(HAVE_COMPATIBLE_GCC_AARCH64_PLATFORM_AS) \ && defined(HAVE_GCC_INLINE_ASM_AARCH64_NEON) # define USE_AARCH64_SIMD 1 # endif #endif /* Assembly implementations use SystemV ABI, ABI conversion and additional * stack to store XMM6-XMM15 needed on Win64. */ #undef ASM_FUNC_ABI #undef ASM_EXTRA_STACK #if defined(HAVE_COMPATIBLE_GCC_WIN64_PLATFORM_AS) # define ASM_FUNC_ABI __attribute__((sysv_abi)) #else # define ASM_FUNC_ABI #endif typedef struct CHACHA20_context_s { u32 input[16]; unsigned char pad[CHACHA20_BLOCK_SIZE]; unsigned int unused; /* bytes in the pad. */ int use_ssse3:1; int use_avx2:1; int use_neon:1; } CHACHA20_context_t; #ifdef USE_SSSE3 unsigned int _gcry_chacha20_amd64_ssse3_blocks4(u32 *state, byte *dst, const byte *src, size_t nblks) ASM_FUNC_ABI; unsigned int _gcry_chacha20_amd64_ssse3_blocks1(u32 *state, byte *dst, const byte *src, size_t nblks) ASM_FUNC_ABI; unsigned int _gcry_chacha20_poly1305_amd64_ssse3_blocks4( u32 *state, byte *dst, const byte *src, size_t nblks, void *poly1305_state, const byte *poly1305_src) ASM_FUNC_ABI; unsigned int _gcry_chacha20_poly1305_amd64_ssse3_blocks1( u32 *state, byte *dst, const byte *src, size_t nblks, void *poly1305_state, const byte *poly1305_src) ASM_FUNC_ABI; #endif /* USE_SSSE3 */ #ifdef USE_AVX2 unsigned int _gcry_chacha20_amd64_avx2_blocks8(u32 *state, byte *dst, const byte *src, size_t nblks) ASM_FUNC_ABI; unsigned int _gcry_chacha20_poly1305_amd64_avx2_blocks8( u32 *state, byte *dst, const byte *src, size_t nblks, void *poly1305_state, const byte *poly1305_src) ASM_FUNC_ABI; #endif /* USE_AVX2 */ #ifdef USE_ARMV7_NEON unsigned int _gcry_chacha20_armv7_neon_blocks4(u32 *state, byte *dst, const byte *src, size_t nblks); #endif /* USE_ARMV7_NEON */ #ifdef USE_AARCH64_SIMD unsigned int _gcry_chacha20_aarch64_blocks4(u32 *state, byte *dst, const byte *src, size_t nblks); #endif /* USE_AARCH64_SIMD */ static const char *selftest (void); #define ROTATE(v,c) (rol(v,c)) #define XOR(v,w) ((v) ^ (w)) #define PLUS(v,w) ((u32)((v) + (w))) #define PLUSONE(v) (PLUS((v),1)) #define QUARTERROUND(a,b,c,d) \ a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \ c = PLUS(c,d); b = ROTATE(XOR(b,c),12); \ a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \ c = PLUS(c,d); b = ROTATE(XOR(b,c), 7); #define BUF_XOR_LE32(dst, src, offset, x) \ buf_put_le32((dst) + (offset), buf_get_le32((src) + (offset)) ^ (x)) static unsigned int do_chacha20_blocks (u32 *input, byte *dst, const byte *src, size_t nblks) { u32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; unsigned int i; while (nblks) { x0 = input[0]; x1 = input[1]; x2 = input[2]; x3 = input[3]; x4 = input[4]; x5 = input[5]; x6 = input[6]; x7 = input[7]; x8 = input[8]; x9 = input[9]; x10 = input[10]; x11 = input[11]; x12 = input[12]; x13 = input[13]; x14 = input[14]; x15 = input[15]; for (i = 20; i > 0; i -= 2) { QUARTERROUND(x0, x4, x8, x12) QUARTERROUND(x1, x5, x9, x13) QUARTERROUND(x2, x6, x10, x14) QUARTERROUND(x3, x7, x11, x15) QUARTERROUND(x0, x5, x10, x15) QUARTERROUND(x1, x6, x11, x12) QUARTERROUND(x2, x7, x8, x13) QUARTERROUND(x3, x4, x9, x14) } x0 = PLUS(x0, input[0]); x1 = PLUS(x1, input[1]); x2 = PLUS(x2, input[2]); x3 = PLUS(x3, input[3]); x4 = PLUS(x4, input[4]); x5 = PLUS(x5, input[5]); x6 = PLUS(x6, input[6]); x7 = PLUS(x7, input[7]); x8 = PLUS(x8, input[8]); x9 = PLUS(x9, input[9]); x10 = PLUS(x10, input[10]); x11 = PLUS(x11, input[11]); x12 = PLUS(x12, input[12]); x13 = PLUS(x13, input[13]); x14 = PLUS(x14, input[14]); x15 = PLUS(x15, input[15]); input[12] = PLUSONE(input[12]); input[13] = PLUS(input[13], !input[12]); BUF_XOR_LE32(dst, src, 0, x0); BUF_XOR_LE32(dst, src, 4, x1); BUF_XOR_LE32(dst, src, 8, x2); BUF_XOR_LE32(dst, src, 12, x3); BUF_XOR_LE32(dst, src, 16, x4); BUF_XOR_LE32(dst, src, 20, x5); BUF_XOR_LE32(dst, src, 24, x6); BUF_XOR_LE32(dst, src, 28, x7); BUF_XOR_LE32(dst, src, 32, x8); BUF_XOR_LE32(dst, src, 36, x9); BUF_XOR_LE32(dst, src, 40, x10); BUF_XOR_LE32(dst, src, 44, x11); BUF_XOR_LE32(dst, src, 48, x12); BUF_XOR_LE32(dst, src, 52, x13); BUF_XOR_LE32(dst, src, 56, x14); BUF_XOR_LE32(dst, src, 60, x15); src += CHACHA20_BLOCK_SIZE; dst += CHACHA20_BLOCK_SIZE; nblks--; } /* burn_stack */ return (17 * sizeof(u32) + 6 * sizeof(void *)); } static unsigned int chacha20_blocks (CHACHA20_context_t *ctx, byte *dst, const byte *src, size_t nblks) { #ifdef USE_SSSE3 if (ctx->use_ssse3) { return _gcry_chacha20_amd64_ssse3_blocks1(ctx->input, dst, src, nblks); } #endif return do_chacha20_blocks (ctx->input, dst, src, nblks); } static void chacha20_keysetup (CHACHA20_context_t *ctx, const byte *key, unsigned int keylen) { static const char sigma[16] = "expand 32-byte k"; static const char tau[16] = "expand 16-byte k"; const char *constants; ctx->input[4] = buf_get_le32(key + 0); ctx->input[5] = buf_get_le32(key + 4); ctx->input[6] = buf_get_le32(key + 8); ctx->input[7] = buf_get_le32(key + 12); if (keylen == CHACHA20_MAX_KEY_SIZE) /* 256 bits */ { key += 16; constants = sigma; } else /* 128 bits */ { constants = tau; } ctx->input[8] = buf_get_le32(key + 0); ctx->input[9] = buf_get_le32(key + 4); ctx->input[10] = buf_get_le32(key + 8); ctx->input[11] = buf_get_le32(key + 12); ctx->input[0] = buf_get_le32(constants + 0); ctx->input[1] = buf_get_le32(constants + 4); ctx->input[2] = buf_get_le32(constants + 8); ctx->input[3] = buf_get_le32(constants + 12); } static void chacha20_ivsetup (CHACHA20_context_t * ctx, const byte *iv, size_t ivlen) { if (ivlen == CHACHA20_CTR_SIZE) { ctx->input[12] = buf_get_le32 (iv + 0); ctx->input[13] = buf_get_le32 (iv + 4); ctx->input[14] = buf_get_le32 (iv + 8); ctx->input[15] = buf_get_le32 (iv + 12); } else if (ivlen == CHACHA20_MAX_IV_SIZE) { ctx->input[12] = 0; ctx->input[13] = buf_get_le32 (iv + 0); ctx->input[14] = buf_get_le32 (iv + 4); ctx->input[15] = buf_get_le32 (iv + 8); } else if (ivlen == CHACHA20_MIN_IV_SIZE) { ctx->input[12] = 0; ctx->input[13] = 0; ctx->input[14] = buf_get_le32 (iv + 0); ctx->input[15] = buf_get_le32 (iv + 4); } else { ctx->input[12] = 0; ctx->input[13] = 0; ctx->input[14] = 0; ctx->input[15] = 0; } } static void chacha20_setiv (void *context, const byte *iv, size_t ivlen) { CHACHA20_context_t *ctx = (CHACHA20_context_t *) context; /* draft-nir-cfrg-chacha20-poly1305-02 defines 96-bit and 64-bit nonce. */ if (iv && ivlen != CHACHA20_MAX_IV_SIZE && ivlen != CHACHA20_MIN_IV_SIZE && ivlen != CHACHA20_CTR_SIZE) log_info ("WARNING: chacha20_setiv: bad ivlen=%u\n", (u32) ivlen); if (iv && (ivlen == CHACHA20_MAX_IV_SIZE || ivlen == CHACHA20_MIN_IV_SIZE || ivlen == CHACHA20_CTR_SIZE)) chacha20_ivsetup (ctx, iv, ivlen); else chacha20_ivsetup (ctx, NULL, 0); /* Reset the unused pad bytes counter. */ ctx->unused = 0; } static gcry_err_code_t chacha20_do_setkey (CHACHA20_context_t *ctx, const byte *key, unsigned int keylen) { static int initialized; static const char *selftest_failed; unsigned int features = _gcry_get_hw_features (); if (!initialized) { initialized = 1; selftest_failed = selftest (); if (selftest_failed) log_error ("CHACHA20 selftest failed (%s)\n", selftest_failed); } if (selftest_failed) return GPG_ERR_SELFTEST_FAILED; if (keylen != CHACHA20_MAX_KEY_SIZE && keylen != CHACHA20_MIN_KEY_SIZE) return GPG_ERR_INV_KEYLEN; #ifdef USE_SSSE3 ctx->use_ssse3 = (features & HWF_INTEL_SSSE3) != 0; #endif #ifdef USE_AVX2 ctx->use_avx2 = (features & HWF_INTEL_AVX2) != 0; #endif #ifdef USE_ARMV7_NEON ctx->use_neon = (features & HWF_ARM_NEON) != 0; #endif #ifdef USE_AARCH64_SIMD ctx->use_neon = (features & HWF_ARM_NEON) != 0; #endif (void)features; chacha20_keysetup (ctx, key, keylen); /* We default to a zero nonce. */ chacha20_setiv (ctx, NULL, 0); return 0; } static gcry_err_code_t chacha20_setkey (void *context, const byte *key, unsigned int keylen, gcry_cipher_hd_t hd) { CHACHA20_context_t *ctx = (CHACHA20_context_t *) context; gcry_err_code_t rc = chacha20_do_setkey (ctx, key, keylen); (void)hd; _gcry_burn_stack (4 + sizeof (void *) + 4 * sizeof (void *)); return rc; } static unsigned int do_chacha20_encrypt_stream_tail (CHACHA20_context_t *ctx, byte *outbuf, const byte *inbuf, size_t length) { static const unsigned char zero_pad[CHACHA20_BLOCK_SIZE] = { 0, }; unsigned int nburn, burn = 0; #ifdef USE_AVX2 if (ctx->use_avx2 && length >= CHACHA20_BLOCK_SIZE * 8) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 8; nburn = _gcry_chacha20_amd64_avx2_blocks8(ctx->input, outbuf, inbuf, nblocks); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_SSSE3 if (ctx->use_ssse3 && length >= CHACHA20_BLOCK_SIZE * 4) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 4; nburn = _gcry_chacha20_amd64_ssse3_blocks4(ctx->input, outbuf, inbuf, nblocks); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_ARMV7_NEON if (ctx->use_neon && length >= CHACHA20_BLOCK_SIZE * 4) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 4; nburn = _gcry_chacha20_armv7_neon_blocks4(ctx->input, outbuf, inbuf, nblocks); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_AARCH64_SIMD if (ctx->use_neon && length >= CHACHA20_BLOCK_SIZE * 4) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 4; nburn = _gcry_chacha20_aarch64_blocks4(ctx->input, outbuf, inbuf, nblocks); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } #endif if (length >= CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nburn = chacha20_blocks(ctx, outbuf, inbuf, nblocks); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } if (length > 0) { nburn = chacha20_blocks(ctx, ctx->pad, zero_pad, 1); burn = nburn > burn ? nburn : burn; buf_xor (outbuf, inbuf, ctx->pad, length); ctx->unused = CHACHA20_BLOCK_SIZE - length; } if (burn) burn += 5 * sizeof(void *); return burn; } static void chacha20_encrypt_stream (void *context, byte *outbuf, const byte *inbuf, size_t length) { CHACHA20_context_t *ctx = (CHACHA20_context_t *) context; unsigned int nburn, burn = 0; if (!length) return; if (ctx->unused) { unsigned char *p = ctx->pad; size_t n; gcry_assert (ctx->unused < CHACHA20_BLOCK_SIZE); n = ctx->unused; if (n > length) n = length; buf_xor (outbuf, inbuf, p + CHACHA20_BLOCK_SIZE - ctx->unused, n); length -= n; outbuf += n; inbuf += n; ctx->unused -= n; if (!length) return; gcry_assert (!ctx->unused); } nburn = do_chacha20_encrypt_stream_tail (ctx, outbuf, inbuf, length); burn = nburn > burn ? nburn : burn; if (burn) _gcry_burn_stack (burn); } gcry_err_code_t _gcry_chacha20_poly1305_encrypt(gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, size_t length) { CHACHA20_context_t *ctx = (void *) &c->context.c; unsigned int nburn, burn = 0; byte *authptr = NULL; if (!length) return 0; if (ctx->unused) { unsigned char *p = ctx->pad; size_t n; gcry_assert (ctx->unused < CHACHA20_BLOCK_SIZE); n = ctx->unused; if (n > length) n = length; buf_xor (outbuf, inbuf, p + CHACHA20_BLOCK_SIZE - ctx->unused, n); nburn = _gcry_poly1305_update_burn (&c->u_mode.poly1305.ctx, outbuf, n); burn = nburn > burn ? nburn : burn; length -= n; outbuf += n; inbuf += n; ctx->unused -= n; if (!length) { if (burn) _gcry_burn_stack (burn); return 0; } gcry_assert (!ctx->unused); } gcry_assert (c->u_mode.poly1305.ctx.leftover == 0); if (0) { } #ifdef USE_AVX2 else if (ctx->use_avx2 && length >= CHACHA20_BLOCK_SIZE * 8) { nburn = _gcry_chacha20_amd64_avx2_blocks8(ctx->input, outbuf, inbuf, 8); burn = nburn > burn ? nburn : burn; authptr = outbuf; length -= 8 * CHACHA20_BLOCK_SIZE; outbuf += 8 * CHACHA20_BLOCK_SIZE; inbuf += 8 * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_SSSE3 else if (ctx->use_ssse3 && length >= CHACHA20_BLOCK_SIZE * 4) { nburn = _gcry_chacha20_amd64_ssse3_blocks4(ctx->input, outbuf, inbuf, 4); burn = nburn > burn ? nburn : burn; authptr = outbuf; length -= 4 * CHACHA20_BLOCK_SIZE; outbuf += 4 * CHACHA20_BLOCK_SIZE; inbuf += 4 * CHACHA20_BLOCK_SIZE; } else if (ctx->use_ssse3 && length >= CHACHA20_BLOCK_SIZE * 2) { nburn = _gcry_chacha20_amd64_ssse3_blocks1(ctx->input, outbuf, inbuf, 2); burn = nburn > burn ? nburn : burn; authptr = outbuf; length -= 2 * CHACHA20_BLOCK_SIZE; outbuf += 2 * CHACHA20_BLOCK_SIZE; inbuf += 2 * CHACHA20_BLOCK_SIZE; } else if (ctx->use_ssse3 && length >= CHACHA20_BLOCK_SIZE) { nburn = _gcry_chacha20_amd64_ssse3_blocks1(ctx->input, outbuf, inbuf, 1); burn = nburn > burn ? nburn : burn; authptr = outbuf; length -= 1 * CHACHA20_BLOCK_SIZE; outbuf += 1 * CHACHA20_BLOCK_SIZE; inbuf += 1 * CHACHA20_BLOCK_SIZE; } #endif if (authptr) { size_t authoffset = outbuf - authptr; #ifdef USE_AVX2 if (ctx->use_avx2 && length >= 8 * CHACHA20_BLOCK_SIZE && authoffset >= 8 * CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 8; nburn = _gcry_chacha20_poly1305_amd64_avx2_blocks8( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, authptr); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; authptr += nblocks * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_SSSE3 if (ctx->use_ssse3) { if (length >= 4 * CHACHA20_BLOCK_SIZE && authoffset >= 4 * CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 4; nburn = _gcry_chacha20_poly1305_amd64_ssse3_blocks4( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, authptr); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; authptr += nblocks * CHACHA20_BLOCK_SIZE; } if (length >= CHACHA20_BLOCK_SIZE && authoffset >= CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nburn = _gcry_chacha20_poly1305_amd64_ssse3_blocks1( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, authptr); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; authptr += nblocks * CHACHA20_BLOCK_SIZE; } } #endif if (authoffset > 0) { _gcry_poly1305_update (&c->u_mode.poly1305.ctx, authptr, authoffset); authptr += authoffset; authoffset = 0; } gcry_assert(authptr == outbuf); } while (length) { size_t currlen = length; /* Since checksumming is done after encryption, process input in 24KiB * chunks to keep data loaded in L1 cache for checksumming. */ if (currlen > 24 * 1024) currlen = 24 * 1024; - nburn = do_chacha20_encrypt_stream_tail (ctx, outbuf, inbuf, length); + nburn = do_chacha20_encrypt_stream_tail (ctx, outbuf, inbuf, currlen); burn = nburn > burn ? nburn : burn; nburn = _gcry_poly1305_update_burn (&c->u_mode.poly1305.ctx, outbuf, currlen); burn = nburn > burn ? nburn : burn; outbuf += currlen; inbuf += currlen; length -= currlen; } if (burn) _gcry_burn_stack (burn); return 0; } gcry_err_code_t _gcry_chacha20_poly1305_decrypt(gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, size_t length) { CHACHA20_context_t *ctx = (void *) &c->context.c; unsigned int nburn, burn = 0; if (!length) return 0; if (ctx->unused) { unsigned char *p = ctx->pad; size_t n; gcry_assert (ctx->unused < CHACHA20_BLOCK_SIZE); n = ctx->unused; if (n > length) n = length; nburn = _gcry_poly1305_update_burn (&c->u_mode.poly1305.ctx, inbuf, n); burn = nburn > burn ? nburn : burn; buf_xor (outbuf, inbuf, p + CHACHA20_BLOCK_SIZE - ctx->unused, n); length -= n; outbuf += n; inbuf += n; ctx->unused -= n; if (!length) { if (burn) _gcry_burn_stack (burn); return 0; } gcry_assert (!ctx->unused); } gcry_assert (c->u_mode.poly1305.ctx.leftover == 0); #ifdef USE_AVX2 if (ctx->use_avx2 && length >= 8 * CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 8; nburn = _gcry_chacha20_poly1305_amd64_avx2_blocks8( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, inbuf); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } #endif #ifdef USE_SSSE3 if (ctx->use_ssse3) { if (length >= 4 * CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nblocks -= nblocks % 4; nburn = _gcry_chacha20_poly1305_amd64_ssse3_blocks4( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, inbuf); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } if (length >= CHACHA20_BLOCK_SIZE) { size_t nblocks = length / CHACHA20_BLOCK_SIZE; nburn = _gcry_chacha20_poly1305_amd64_ssse3_blocks1( ctx->input, outbuf, inbuf, nblocks, &c->u_mode.poly1305.ctx.state, inbuf); burn = nburn > burn ? nburn : burn; length -= nblocks * CHACHA20_BLOCK_SIZE; outbuf += nblocks * CHACHA20_BLOCK_SIZE; inbuf += nblocks * CHACHA20_BLOCK_SIZE; } } #endif while (length) { size_t currlen = length; /* Since checksumming is done before decryption, process input in 24KiB * chunks to keep data loaded in L1 cache for decryption. */ if (currlen > 24 * 1024) currlen = 24 * 1024; nburn = _gcry_poly1305_update_burn (&c->u_mode.poly1305.ctx, inbuf, currlen); burn = nburn > burn ? nburn : burn; - nburn = do_chacha20_encrypt_stream_tail (ctx, outbuf, inbuf, length); + nburn = do_chacha20_encrypt_stream_tail (ctx, outbuf, inbuf, currlen); burn = nburn > burn ? nburn : burn; outbuf += currlen; inbuf += currlen; length -= currlen; } if (burn) _gcry_burn_stack (burn); return 0; } static const char * selftest (void) { byte ctxbuf[sizeof(CHACHA20_context_t) + 15]; CHACHA20_context_t *ctx; byte scratch[127 + 1]; byte buf[512 + 64 + 4]; int i; /* From draft-strombergson-chacha-test-vectors */ static byte key_1[] = { 0xc4, 0x6e, 0xc1, 0xb1, 0x8c, 0xe8, 0xa8, 0x78, 0x72, 0x5a, 0x37, 0xe7, 0x80, 0xdf, 0xb7, 0x35, 0x1f, 0x68, 0xed, 0x2e, 0x19, 0x4c, 0x79, 0xfb, 0xc6, 0xae, 0xbe, 0xe1, 0xa6, 0x67, 0x97, 0x5d }; static const byte nonce_1[] = { 0x1a, 0xda, 0x31, 0xd5, 0xcf, 0x68, 0x82, 0x21 }; static const byte plaintext_1[127] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }; static const byte ciphertext_1[127] = { 0xf6, 0x3a, 0x89, 0xb7, 0x5c, 0x22, 0x71, 0xf9, 0x36, 0x88, 0x16, 0x54, 0x2b, 0xa5, 0x2f, 0x06, 0xed, 0x49, 0x24, 0x17, 0x92, 0x30, 0x2b, 0x00, 0xb5, 0xe8, 0xf8, 0x0a, 0xe9, 0xa4, 0x73, 0xaf, 0xc2, 0x5b, 0x21, 0x8f, 0x51, 0x9a, 0xf0, 0xfd, 0xd4, 0x06, 0x36, 0x2e, 0x8d, 0x69, 0xde, 0x7f, 0x54, 0xc6, 0x04, 0xa6, 0xe0, 0x0f, 0x35, 0x3f, 0x11, 0x0f, 0x77, 0x1b, 0xdc, 0xa8, 0xab, 0x92, 0xe5, 0xfb, 0xc3, 0x4e, 0x60, 0xa1, 0xd9, 0xa9, 0xdb, 0x17, 0x34, 0x5b, 0x0a, 0x40, 0x27, 0x36, 0x85, 0x3b, 0xf9, 0x10, 0xb0, 0x60, 0xbd, 0xf1, 0xf8, 0x97, 0xb6, 0x29, 0x0f, 0x01, 0xd1, 0x38, 0xae, 0x2c, 0x4c, 0x90, 0x22, 0x5b, 0xa9, 0xea, 0x14, 0xd5, 0x18, 0xf5, 0x59, 0x29, 0xde, 0xa0, 0x98, 0xca, 0x7a, 0x6c, 0xcf, 0xe6, 0x12, 0x27, 0x05, 0x3c, 0x84, 0xe4, 0x9a, 0x4a, 0x33 }; /* 16-byte alignment required for amd64 implementation. */ ctx = (CHACHA20_context_t *)((uintptr_t)(ctxbuf + 15) & ~(uintptr_t)15); chacha20_setkey (ctx, key_1, sizeof key_1, NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); scratch[sizeof (scratch) - 1] = 0; chacha20_encrypt_stream (ctx, scratch, plaintext_1, sizeof plaintext_1); if (memcmp (scratch, ciphertext_1, sizeof ciphertext_1)) return "ChaCha20 encryption test 1 failed."; if (scratch[sizeof (scratch) - 1]) return "ChaCha20 wrote too much."; chacha20_setkey (ctx, key_1, sizeof (key_1), NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); chacha20_encrypt_stream (ctx, scratch, scratch, sizeof plaintext_1); if (memcmp (scratch, plaintext_1, sizeof plaintext_1)) return "ChaCha20 decryption test 1 failed."; for (i = 0; i < sizeof buf; i++) buf[i] = i; chacha20_setkey (ctx, key_1, sizeof key_1, NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); /*encrypt */ chacha20_encrypt_stream (ctx, buf, buf, sizeof buf); /*decrypt */ chacha20_setkey (ctx, key_1, sizeof key_1, NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); chacha20_encrypt_stream (ctx, buf, buf, 1); chacha20_encrypt_stream (ctx, buf + 1, buf + 1, (sizeof buf) - 1 - 1); chacha20_encrypt_stream (ctx, buf + (sizeof buf) - 1, buf + (sizeof buf) - 1, 1); for (i = 0; i < sizeof buf; i++) if (buf[i] != (byte) i) return "ChaCha20 encryption test 2 failed."; chacha20_setkey (ctx, key_1, sizeof key_1, NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); /* encrypt */ for (i = 0; i < sizeof buf; i++) chacha20_encrypt_stream (ctx, &buf[i], &buf[i], 1); /* decrypt */ chacha20_setkey (ctx, key_1, sizeof key_1, NULL); chacha20_setiv (ctx, nonce_1, sizeof nonce_1); chacha20_encrypt_stream (ctx, buf, buf, sizeof buf); for (i = 0; i < sizeof buf; i++) if (buf[i] != (byte) i) return "ChaCha20 encryption test 3 failed."; return NULL; } gcry_cipher_spec_t _gcry_cipher_spec_chacha20 = { GCRY_CIPHER_CHACHA20, {0, 0}, /* flags */ "CHACHA20", /* name */ NULL, /* aliases */ NULL, /* oids */ 1, /* blocksize in bytes. */ CHACHA20_MAX_KEY_SIZE * 8, /* standard key length in bits. */ sizeof (CHACHA20_context_t), chacha20_setkey, NULL, NULL, chacha20_encrypt_stream, chacha20_encrypt_stream, NULL, NULL, chacha20_setiv };