diff options
-rw-r--r-- | arch/arm64/crypto/Kconfig | 5 | ||||
-rw-r--r-- | arch/arm64/crypto/Makefile | 3 | ||||
-rw-r--r-- | arch/arm64/crypto/polyval-ce-core.S | 361 | ||||
-rw-r--r-- | arch/arm64/crypto/polyval-ce-glue.c | 191 |
4 files changed, 560 insertions, 0 deletions
diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig index 74d5bed9394f..4391a463abd7 100644 --- a/arch/arm64/crypto/Kconfig +++ b/arch/arm64/crypto/Kconfig @@ -72,6 +72,11 @@ config CRYPTO_GHASH_ARM64_CE select CRYPTO_GF128MUL select CRYPTO_LIB_AES +config CRYPTO_POLYVAL_ARM64_CE + tristate "POLYVAL using ARMv8 Crypto Extensions (for HCTR2)" + depends on KERNEL_MODE_NEON + select CRYPTO_POLYVAL + config CRYPTO_CRCT10DIF_ARM64_CE tristate "CRCT10DIF digest algorithm using PMULL instructions" depends on KERNEL_MODE_NEON && CRC_T10DIF diff --git a/arch/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile index bea8995133b1..24bb0c4610de 100644 --- a/arch/arm64/crypto/Makefile +++ b/arch/arm64/crypto/Makefile @@ -32,6 +32,9 @@ sm4-neon-y := sm4-neon-glue.o sm4-neon-core.o obj-$(CONFIG_CRYPTO_GHASH_ARM64_CE) += ghash-ce.o ghash-ce-y := ghash-ce-glue.o ghash-ce-core.o +obj-$(CONFIG_CRYPTO_POLYVAL_ARM64_CE) += polyval-ce.o +polyval-ce-y := polyval-ce-glue.o polyval-ce-core.o + obj-$(CONFIG_CRYPTO_CRCT10DIF_ARM64_CE) += crct10dif-ce.o crct10dif-ce-y := crct10dif-ce-core.o crct10dif-ce-glue.o diff --git a/arch/arm64/crypto/polyval-ce-core.S b/arch/arm64/crypto/polyval-ce-core.S new file mode 100644 index 000000000000..b5326540d2e3 --- /dev/null +++ b/arch/arm64/crypto/polyval-ce-core.S @@ -0,0 +1,361 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Implementation of POLYVAL using ARMv8 Crypto Extensions. + * + * Copyright 2021 Google LLC + */ +/* + * This is an efficient implementation of POLYVAL using ARMv8 Crypto Extensions + * It works on 8 blocks at a time, by precomputing the first 8 keys powers h^8, + * ..., h^1 in the POLYVAL finite field. This precomputation allows us to split + * finite field multiplication into two steps. + * + * In the first step, we consider h^i, m_i as normal polynomials of degree less + * than 128. We then compute p(x) = h^8m_0 + ... + h^1m_7 where multiplication + * is simply polynomial multiplication. + * + * In the second step, we compute the reduction of p(x) modulo the finite field + * modulus g(x) = x^128 + x^127 + x^126 + x^121 + 1. + * + * This two step process is equivalent to computing h^8m_0 + ... + h^1m_7 where + * multiplication is finite field multiplication. The advantage is that the + * two-step process only requires 1 finite field reduction for every 8 + * polynomial multiplications. Further parallelism is gained by interleaving the + * multiplications and polynomial reductions. + */ + +#include <linux/linkage.h> +#define STRIDE_BLOCKS 8 + +KEY_POWERS .req x0 +MSG .req x1 +BLOCKS_LEFT .req x2 +ACCUMULATOR .req x3 +KEY_START .req x10 +EXTRA_BYTES .req x11 +TMP .req x13 + +M0 .req v0 +M1 .req v1 +M2 .req v2 +M3 .req v3 +M4 .req v4 +M5 .req v5 +M6 .req v6 +M7 .req v7 +KEY8 .req v8 +KEY7 .req v9 +KEY6 .req v10 +KEY5 .req v11 +KEY4 .req v12 +KEY3 .req v13 +KEY2 .req v14 +KEY1 .req v15 +PL .req v16 +PH .req v17 +TMP_V .req v18 +LO .req v20 +MI .req v21 +HI .req v22 +SUM .req v23 +GSTAR .req v24 + + .text + + .arch armv8-a+crypto + .align 4 + +.Lgstar: + .quad 0xc200000000000000, 0xc200000000000000 + +/* + * Computes the product of two 128-bit polynomials in X and Y and XORs the + * components of the 256-bit product into LO, MI, HI. + * + * Given: + * X = [X_1 : X_0] + * Y = [Y_1 : Y_0] + * + * We compute: + * LO += X_0 * Y_0 + * MI += (X_0 + X_1) * (Y_0 + Y_1) + * HI += X_1 * Y_1 + * + * Later, the 256-bit result can be extracted as: + * [HI_1 : HI_0 + HI_1 + MI_1 + LO_1 : LO_1 + HI_0 + MI_0 + LO_0 : LO_0] + * This step is done when computing the polynomial reduction for efficiency + * reasons. + * + * Karatsuba multiplication is used instead of Schoolbook multiplication because + * it was found to be slightly faster on ARM64 CPUs. + * + */ +.macro karatsuba1 X Y + X .req \X + Y .req \Y + ext v25.16b, X.16b, X.16b, #8 + ext v26.16b, Y.16b, Y.16b, #8 + eor v25.16b, v25.16b, X.16b + eor v26.16b, v26.16b, Y.16b + pmull2 v28.1q, X.2d, Y.2d + pmull v29.1q, X.1d, Y.1d + pmull v27.1q, v25.1d, v26.1d + eor HI.16b, HI.16b, v28.16b + eor LO.16b, LO.16b, v29.16b + eor MI.16b, MI.16b, v27.16b + .unreq X + .unreq Y +.endm + +/* + * Same as karatsuba1, except overwrites HI, LO, MI rather than XORing into + * them. + */ +.macro karatsuba1_store X Y + X .req \X + Y .req \Y + ext v25.16b, X.16b, X.16b, #8 + ext v26.16b, Y.16b, Y.16b, #8 + eor v25.16b, v25.16b, X.16b + eor v26.16b, v26.16b, Y.16b + pmull2 HI.1q, X.2d, Y.2d + pmull LO.1q, X.1d, Y.1d + pmull MI.1q, v25.1d, v26.1d + .unreq X + .unreq Y +.endm + +/* + * Computes the 256-bit polynomial represented by LO, HI, MI. Stores + * the result in PL, PH. + * [PH : PL] = + * [HI_1 : HI_1 + HI_0 + MI_1 + LO_1 : HI_0 + MI_0 + LO_1 + LO_0 : LO_0] + */ +.macro karatsuba2 + // v4 = [HI_1 + MI_1 : HI_0 + MI_0] + eor v4.16b, HI.16b, MI.16b + // v4 = [HI_1 + MI_1 + LO_1 : HI_0 + MI_0 + LO_0] + eor v4.16b, v4.16b, LO.16b + // v5 = [HI_0 : LO_1] + ext v5.16b, LO.16b, HI.16b, #8 + // v4 = [HI_1 + HI_0 + MI_1 + LO_1 : HI_0 + MI_0 + LO_1 + LO_0] + eor v4.16b, v4.16b, v5.16b + // HI = [HI_0 : HI_1] + ext HI.16b, HI.16b, HI.16b, #8 + // LO = [LO_0 : LO_1] + ext LO.16b, LO.16b, LO.16b, #8 + // PH = [HI_1 : HI_1 + HI_0 + MI_1 + LO_1] + ext PH.16b, v4.16b, HI.16b, #8 + // PL = [HI_0 + MI_0 + LO_1 + LO_0 : LO_0] + ext PL.16b, LO.16b, v4.16b, #8 +.endm + +/* + * Computes the 128-bit reduction of PH : PL. Stores the result in dest. + * + * This macro computes p(x) mod g(x) where p(x) is in montgomery form and g(x) = + * x^128 + x^127 + x^126 + x^121 + 1. + * + * We have a 256-bit polynomial PH : PL = P_3 : P_2 : P_1 : P_0 that is the + * product of two 128-bit polynomials in Montgomery form. We need to reduce it + * mod g(x). Also, since polynomials in Montgomery form have an "extra" factor + * of x^128, this product has two extra factors of x^128. To get it back into + * Montgomery form, we need to remove one of these factors by dividing by x^128. + * + * To accomplish both of these goals, we add multiples of g(x) that cancel out + * the low 128 bits P_1 : P_0, leaving just the high 128 bits. Since the low + * bits are zero, the polynomial division by x^128 can be done by right + * shifting. + * + * Since the only nonzero term in the low 64 bits of g(x) is the constant term, + * the multiple of g(x) needed to cancel out P_0 is P_0 * g(x). The CPU can + * only do 64x64 bit multiplications, so split P_0 * g(x) into x^128 * P_0 + + * x^64 * g*(x) * P_0 + P_0, where g*(x) is bits 64-127 of g(x). Adding this to + * the original polynomial gives P_3 : P_2 + P_0 + T_1 : P_1 + T_0 : 0, where T + * = T_1 : T_0 = g*(x) * P_0. Thus, bits 0-63 got "folded" into bits 64-191. + * + * Repeating this same process on the next 64 bits "folds" bits 64-127 into bits + * 128-255, giving the answer in bits 128-255. This time, we need to cancel P_1 + * + T_0 in bits 64-127. The multiple of g(x) required is (P_1 + T_0) * g(x) * + * x^64. Adding this to our previous computation gives P_3 + P_1 + T_0 + V_1 : + * P_2 + P_0 + T_1 + V_0 : 0 : 0, where V = V_1 : V_0 = g*(x) * (P_1 + T_0). + * + * So our final computation is: + * T = T_1 : T_0 = g*(x) * P_0 + * V = V_1 : V_0 = g*(x) * (P_1 + T_0) + * p(x) / x^{128} mod g(x) = P_3 + P_1 + T_0 + V_1 : P_2 + P_0 + T_1 + V_0 + * + * The implementation below saves a XOR instruction by computing P_1 + T_0 : P_0 + * + T_1 and XORing into dest, rather than separately XORing P_1 : P_0 and T_0 : + * T_1 into dest. This allows us to reuse P_1 + T_0 when computing V. + */ +.macro montgomery_reduction dest + DEST .req \dest + // TMP_V = T_1 : T_0 = P_0 * g*(x) + pmull TMP_V.1q, PL.1d, GSTAR.1d + // TMP_V = T_0 : T_1 + ext TMP_V.16b, TMP_V.16b, TMP_V.16b, #8 + // TMP_V = P_1 + T_0 : P_0 + T_1 + eor TMP_V.16b, PL.16b, TMP_V.16b + // PH = P_3 + P_1 + T_0 : P_2 + P_0 + T_1 + eor PH.16b, PH.16b, TMP_V.16b + // TMP_V = V_1 : V_0 = (P_1 + T_0) * g*(x) + pmull2 TMP_V.1q, TMP_V.2d, GSTAR.2d + eor DEST.16b, PH.16b, TMP_V.16b + .unreq DEST +.endm + +/* + * Compute Polyval on 8 blocks. + * + * If reduce is set, also computes the montgomery reduction of the + * previous full_stride call and XORs with the first message block. + * (m_0 + REDUCE(PL, PH))h^8 + ... + m_7h^1. + * I.e., the first multiplication uses m_0 + REDUCE(PL, PH) instead of m_0. + * + * Sets PL, PH. + */ +.macro full_stride reduce + eor LO.16b, LO.16b, LO.16b + eor MI.16b, MI.16b, MI.16b + eor HI.16b, HI.16b, HI.16b + + ld1 {M0.16b, M1.16b, M2.16b, M3.16b}, [MSG], #64 + ld1 {M4.16b, M5.16b, M6.16b, M7.16b}, [MSG], #64 + + karatsuba1 M7 KEY1 + .if \reduce + pmull TMP_V.1q, PL.1d, GSTAR.1d + .endif + + karatsuba1 M6 KEY2 + .if \reduce + ext TMP_V.16b, TMP_V.16b, TMP_V.16b, #8 + .endif + + karatsuba1 M5 KEY3 + .if \reduce + eor TMP_V.16b, PL.16b, TMP_V.16b + .endif + + karatsuba1 M4 KEY4 + .if \reduce + eor PH.16b, PH.16b, TMP_V.16b + .endif + + karatsuba1 M3 KEY5 + .if \reduce + pmull2 TMP_V.1q, TMP_V.2d, GSTAR.2d + .endif + + karatsuba1 M2 KEY6 + .if \reduce + eor SUM.16b, PH.16b, TMP_V.16b + .endif + + karatsuba1 M1 KEY7 + eor M0.16b, M0.16b, SUM.16b + + karatsuba1 M0 KEY8 + karatsuba2 +.endm + +/* + * Handle any extra blocks after full_stride loop. + */ +.macro partial_stride + add KEY_POWERS, KEY_START, #(STRIDE_BLOCKS << 4) + sub KEY_POWERS, KEY_POWERS, BLOCKS_LEFT, lsl #4 + ld1 {KEY1.16b}, [KEY_POWERS], #16 + + ld1 {TMP_V.16b}, [MSG], #16 + eor SUM.16b, SUM.16b, TMP_V.16b + karatsuba1_store KEY1 SUM + sub BLOCKS_LEFT, BLOCKS_LEFT, #1 + + tst BLOCKS_LEFT, #4 + beq .Lpartial4BlocksDone + ld1 {M0.16b, M1.16b, M2.16b, M3.16b}, [MSG], #64 + ld1 {KEY8.16b, KEY7.16b, KEY6.16b, KEY5.16b}, [KEY_POWERS], #64 + karatsuba1 M0 KEY8 + karatsuba1 M1 KEY7 + karatsuba1 M2 KEY6 + karatsuba1 M3 KEY5 +.Lpartial4BlocksDone: + tst BLOCKS_LEFT, #2 + beq .Lpartial2BlocksDone + ld1 {M0.16b, M1.16b}, [MSG], #32 + ld1 {KEY8.16b, KEY7.16b}, [KEY_POWERS], #32 + karatsuba1 M0 KEY8 + karatsuba1 M1 KEY7 +.Lpartial2BlocksDone: + tst BLOCKS_LEFT, #1 + beq .LpartialDone + ld1 {M0.16b}, [MSG], #16 + ld1 {KEY8.16b}, [KEY_POWERS], #16 + karatsuba1 M0 KEY8 +.LpartialDone: + karatsuba2 + montgomery_reduction SUM +.endm + +/* + * Perform montgomery multiplication in GF(2^128) and store result in op1. + * + * Computes op1*op2*x^{-128} mod x^128 + x^127 + x^126 + x^121 + 1 + * If op1, op2 are in montgomery form, this computes the montgomery + * form of op1*op2. + * + * void pmull_polyval_mul(u8 *op1, const u8 *op2); + */ +SYM_FUNC_START(pmull_polyval_mul) + adr TMP, .Lgstar + ld1 {GSTAR.2d}, [TMP] + ld1 {v0.16b}, [x0] + ld1 {v1.16b}, [x1] + karatsuba1_store v0 v1 + karatsuba2 + montgomery_reduction SUM + st1 {SUM.16b}, [x0] + ret +SYM_FUNC_END(pmull_polyval_mul) + +/* + * Perform polynomial evaluation as specified by POLYVAL. This computes: + * h^n * accumulator + h^n * m_0 + ... + h^1 * m_{n-1} + * where n=nblocks, h is the hash key, and m_i are the message blocks. + * + * x0 - pointer to precomputed key powers h^8 ... h^1 + * x1 - pointer to message blocks + * x2 - number of blocks to hash + * x3 - pointer to accumulator + * + * void pmull_polyval_update(const struct polyval_ctx *ctx, const u8 *in, + * size_t nblocks, u8 *accumulator); + */ +SYM_FUNC_START(pmull_polyval_update) + adr TMP, .Lgstar + mov KEY_START, KEY_POWERS + ld1 {GSTAR.2d}, [TMP] + ld1 {SUM.16b}, [ACCUMULATOR] + subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS + blt .LstrideLoopExit + ld1 {KEY8.16b, KEY7.16b, KEY6.16b, KEY5.16b}, [KEY_POWERS], #64 + ld1 {KEY4.16b, KEY3.16b, KEY2.16b, KEY1.16b}, [KEY_POWERS], #64 + full_stride 0 + subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS + blt .LstrideLoopExitReduce +.LstrideLoop: + full_stride 1 + subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS + bge .LstrideLoop +.LstrideLoopExitReduce: + montgomery_reduction SUM +.LstrideLoopExit: + adds BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS + beq .LskipPartial + partial_stride +.LskipPartial: + st1 {SUM.16b}, [ACCUMULATOR] + ret +SYM_FUNC_END(pmull_polyval_update) diff --git a/arch/arm64/crypto/polyval-ce-glue.c b/arch/arm64/crypto/polyval-ce-glue.c new file mode 100644 index 000000000000..0a3b5718df85 --- /dev/null +++ b/arch/arm64/crypto/polyval-ce-glue.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Glue code for POLYVAL using ARMv8 Crypto Extensions + * + * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi> + * Copyright (c) 2009 Intel Corp. + * Author: Huang Ying <ying.huang@intel.com> + * Copyright 2021 Google LLC + */ + +/* + * Glue code based on ghash-clmulni-intel_glue.c. + * + * This implementation of POLYVAL uses montgomery multiplication accelerated by + * ARMv8 Crypto Extensions instructions to implement the finite field operations. + */ + +#include <crypto/algapi.h> +#include <crypto/internal/hash.h> +#include <crypto/internal/simd.h> +#include <crypto/polyval.h> +#include <linux/crypto.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/cpufeature.h> +#include <asm/neon.h> +#include <asm/simd.h> + +#define NUM_KEY_POWERS 8 + +struct polyval_tfm_ctx { + /* + * These powers must be in the order h^8, ..., h^1. + */ + u8 key_powers[NUM_KEY_POWERS][POLYVAL_BLOCK_SIZE]; +}; + +struct polyval_desc_ctx { + u8 buffer[POLYVAL_BLOCK_SIZE]; + u32 bytes; +}; + +asmlinkage void pmull_polyval_update(const struct polyval_tfm_ctx *keys, + const u8 *in, size_t nblocks, u8 *accumulator); +asmlinkage void pmull_polyval_mul(u8 *op1, const u8 *op2); + +static void internal_polyval_update(const struct polyval_tfm_ctx *keys, + const u8 *in, size_t nblocks, u8 *accumulator) +{ + if (likely(crypto_simd_usable())) { + kernel_neon_begin(); + pmull_polyval_update(keys, in, nblocks, accumulator); + kernel_neon_end(); + } else { + polyval_update_non4k(keys->key_powers[NUM_KEY_POWERS-1], in, + nblocks, accumulator); + } +} + +static void internal_polyval_mul(u8 *op1, const u8 *op2) +{ + if (likely(crypto_simd_usable())) { + kernel_neon_begin(); + pmull_polyval_mul(op1, op2); + kernel_neon_end(); + } else { + polyval_mul_non4k(op1, op2); + } +} + +static int polyval_arm64_setkey(struct crypto_shash *tfm, + const u8 *key, unsigned int keylen) +{ + struct polyval_tfm_ctx *tctx = crypto_shash_ctx(tfm); + int i; + + if (keylen != POLYVAL_BLOCK_SIZE) + return -EINVAL; + + memcpy(tctx->key_powers[NUM_KEY_POWERS-1], key, POLYVAL_BLOCK_SIZE); + + for (i = NUM_KEY_POWERS-2; i >= 0; i--) { + memcpy(tctx->key_powers[i], key, POLYVAL_BLOCK_SIZE); + internal_polyval_mul(tctx->key_powers[i], + tctx->key_powers[i+1]); + } + + return 0; +} + +static int polyval_arm64_init(struct shash_desc *desc) +{ + struct polyval_desc_ctx *dctx = shash_desc_ctx(desc); + + memset(dctx, 0, sizeof(*dctx)); + + return 0; +} + +static int polyval_arm64_update(struct shash_desc *desc, + const u8 *src, unsigned int srclen) +{ + struct polyval_desc_ctx *dctx = shash_desc_ctx(desc); + const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); + u8 *pos; + unsigned int nblocks; + unsigned int n; + + if (dctx->bytes) { + n = min(srclen, dctx->bytes); + pos = dctx->buffer + POLYVAL_BLOCK_SIZE - dctx->bytes; + + dctx->bytes -= n; + srclen -= n; + + while (n--) + *pos++ ^= *src++; + + if (!dctx->bytes) + internal_polyval_mul(dctx->buffer, + tctx->key_powers[NUM_KEY_POWERS-1]); + } + + while (srclen >= POLYVAL_BLOCK_SIZE) { + /* allow rescheduling every 4K bytes */ + nblocks = min(srclen, 4096U) / POLYVAL_BLOCK_SIZE; + internal_polyval_update(tctx, src, nblocks, dctx->buffer); + srclen -= nblocks * POLYVAL_BLOCK_SIZE; + src += nblocks * POLYVAL_BLOCK_SIZE; + } + + if (srclen) { + dctx->bytes = POLYVAL_BLOCK_SIZE - srclen; + pos = dctx->buffer; + while (srclen--) + *pos++ ^= *src++; + } + + return 0; +} + +static int polyval_arm64_final(struct shash_desc *desc, u8 *dst) +{ + struct polyval_desc_ctx *dctx = shash_desc_ctx(desc); + const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); + + if (dctx->bytes) { + internal_polyval_mul(dctx->buffer, + tctx->key_powers[NUM_KEY_POWERS-1]); + } + + memcpy(dst, dctx->buffer, POLYVAL_BLOCK_SIZE); + + return 0; +} + +static struct shash_alg polyval_alg = { + .digestsize = POLYVAL_DIGEST_SIZE, + .init = polyval_arm64_init, + .update = polyval_arm64_update, + .final = polyval_arm64_final, + .setkey = polyval_arm64_setkey, + .descsize = sizeof(struct polyval_desc_ctx), + .base = { + .cra_name = "polyval", + .cra_driver_name = "polyval-ce", + .cra_priority = 200, + .cra_blocksize = POLYVAL_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct polyval_tfm_ctx), + .cra_module = THIS_MODULE, + }, +}; + +static int __init polyval_ce_mod_init(void) +{ + return crypto_register_shash(&polyval_alg); +} + +static void __exit polyval_ce_mod_exit(void) +{ + crypto_unregister_shash(&polyval_alg); +} + +module_cpu_feature_match(PMULL, polyval_ce_mod_init) +module_exit(polyval_ce_mod_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("POLYVAL hash function accelerated by ARMv8 Crypto Extensions"); +MODULE_ALIAS_CRYPTO("polyval"); +MODULE_ALIAS_CRYPTO("polyval-ce"); |