crypto: arm64/chacha20 - refactor to allow varying number of rounds
In preparation for adding XChaCha12 support, rename/refactor the ARM64 NEON implementation of ChaCha20 to support different numbers of rounds. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers
Herbert Xu
parent
cc7cf991e9
commit
95a34b779e
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@ -50,8 +50,8 @@ sha256-arm64-y := sha256-glue.o sha256-core.o
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obj-$(CONFIG_CRYPTO_SHA512_ARM64) += sha512-arm64.o
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sha512-arm64-y := sha512-glue.o sha512-core.o
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obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha20-neon.o
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chacha20-neon-y := chacha20-neon-core.o chacha20-neon-glue.o
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obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
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chacha-neon-y := chacha-neon-core.o chacha-neon-glue.o
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obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
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nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o
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@ -1,5 +1,5 @@
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/*
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* ChaCha20 256-bit cipher algorithm, RFC7539, arm64 NEON functions
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* ChaCha/XChaCha NEON helper functions
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*
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* Copyright (C) 2016 Linaro, Ltd. <ard.biesheuvel@linaro.org>
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*
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@ -24,17 +24,18 @@
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.align 6
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/*
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* chacha20_permute - permute one block
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* chacha_permute - permute one block
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*
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* Permute one 64-byte block where the state matrix is stored in the four NEON
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* registers v0-v3. It performs matrix operations on four words in parallel,
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* but requires shuffling to rearrange the words after each round.
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*
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* Clobbers: x3, x10, v4, v12
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* The round count is given in w3.
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*
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* Clobbers: w3, x10, v4, v12
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*/
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chacha20_permute:
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chacha_permute:
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mov x3, #10
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adr x10, ROT8
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ld1 {v12.4s}, [x10]
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@ -97,16 +98,17 @@ chacha20_permute:
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// x3 = shuffle32(x3, MASK(0, 3, 2, 1))
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ext v3.16b, v3.16b, v3.16b, #4
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subs x3, x3, #1
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subs w3, w3, #2
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b.ne .Ldoubleround
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ret
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ENDPROC(chacha20_permute)
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ENDPROC(chacha_permute)
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ENTRY(chacha20_block_xor_neon)
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ENTRY(chacha_block_xor_neon)
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// x0: Input state matrix, s
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// x1: 1 data block output, o
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// x2: 1 data block input, i
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// w3: nrounds
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stp x29, x30, [sp, #-16]!
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mov x29, sp
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@ -115,7 +117,7 @@ ENTRY(chacha20_block_xor_neon)
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ld1 {v0.4s-v3.4s}, [x0]
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ld1 {v8.4s-v11.4s}, [x0]
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bl chacha20_permute
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bl chacha_permute
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ld1 {v4.16b-v7.16b}, [x2]
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@ -139,42 +141,45 @@ ENTRY(chacha20_block_xor_neon)
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ldp x29, x30, [sp], #16
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ret
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ENDPROC(chacha20_block_xor_neon)
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ENDPROC(chacha_block_xor_neon)
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ENTRY(hchacha20_block_neon)
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ENTRY(hchacha_block_neon)
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// x0: Input state matrix, s
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// x1: output (8 32-bit words)
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// w2: nrounds
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stp x29, x30, [sp, #-16]!
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mov x29, sp
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ld1 {v0.4s-v3.4s}, [x0]
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bl chacha20_permute
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mov w3, w2
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bl chacha_permute
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st1 {v0.16b}, [x1], #16
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st1 {v3.16b}, [x1]
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ldp x29, x30, [sp], #16
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ret
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ENDPROC(hchacha20_block_neon)
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ENDPROC(hchacha_block_neon)
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.align 6
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ENTRY(chacha20_4block_xor_neon)
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ENTRY(chacha_4block_xor_neon)
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// x0: Input state matrix, s
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// x1: 4 data blocks output, o
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// x2: 4 data blocks input, i
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// w3: nrounds
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//
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// This function encrypts four consecutive ChaCha20 blocks by loading
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// This function encrypts four consecutive ChaCha blocks by loading
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// the state matrix in NEON registers four times. The algorithm performs
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// each operation on the corresponding word of each state matrix, hence
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// requires no word shuffling. For final XORing step we transpose the
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// matrix by interleaving 32- and then 64-bit words, which allows us to
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// do XOR in NEON registers.
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//
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adr x3, CTRINC // ... and ROT8
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ld1 {v30.4s-v31.4s}, [x3]
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adr x9, CTRINC // ... and ROT8
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ld1 {v30.4s-v31.4s}, [x9]
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// x0..15[0-3] = s0..3[0..3]
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mov x4, x0
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@ -186,8 +191,6 @@ ENTRY(chacha20_4block_xor_neon)
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// x12 += counter values 0-3
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add v12.4s, v12.4s, v30.4s
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mov x3, #10
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.Ldoubleround4:
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// x0 += x4, x12 = rotl32(x12 ^ x0, 16)
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// x1 += x5, x13 = rotl32(x13 ^ x1, 16)
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@ -361,7 +364,7 @@ ENTRY(chacha20_4block_xor_neon)
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sri v7.4s, v18.4s, #25
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sri v4.4s, v19.4s, #25
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subs x3, x3, #1
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subs w3, w3, #2
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b.ne .Ldoubleround4
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ld4r {v16.4s-v19.4s}, [x0], #16
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@ -475,7 +478,7 @@ ENTRY(chacha20_4block_xor_neon)
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st1 {v28.16b-v31.16b}, [x1]
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ret
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ENDPROC(chacha20_4block_xor_neon)
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ENDPROC(chacha_4block_xor_neon)
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CTRINC: .word 0, 1, 2, 3
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ROT8: .word 0x02010003, 0x06050407, 0x0a09080b, 0x0e0d0c0f
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@ -1,5 +1,6 @@
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/*
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* ChaCha20 256-bit cipher algorithm, RFC7539, arm64 NEON functions
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* ARM NEON accelerated ChaCha and XChaCha stream ciphers,
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* including ChaCha20 (RFC7539)
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*
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* Copyright (C) 2016 - 2017 Linaro, Ltd. <ard.biesheuvel@linaro.org>
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*
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@ -28,18 +29,20 @@
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#include <asm/neon.h>
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#include <asm/simd.h>
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asmlinkage void chacha20_block_xor_neon(u32 *state, u8 *dst, const u8 *src);
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asmlinkage void chacha20_4block_xor_neon(u32 *state, u8 *dst, const u8 *src);
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asmlinkage void hchacha20_block_neon(const u32 *state, u32 *out);
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asmlinkage void chacha_block_xor_neon(u32 *state, u8 *dst, const u8 *src,
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int nrounds);
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asmlinkage void chacha_4block_xor_neon(u32 *state, u8 *dst, const u8 *src,
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int nrounds);
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asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);
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static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src,
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unsigned int bytes)
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static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
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unsigned int bytes, int nrounds)
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{
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u8 buf[CHACHA_BLOCK_SIZE];
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while (bytes >= CHACHA_BLOCK_SIZE * 4) {
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kernel_neon_begin();
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chacha20_4block_xor_neon(state, dst, src);
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chacha_4block_xor_neon(state, dst, src, nrounds);
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kernel_neon_end();
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bytes -= CHACHA_BLOCK_SIZE * 4;
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src += CHACHA_BLOCK_SIZE * 4;
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@ -52,7 +55,7 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src,
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kernel_neon_begin();
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while (bytes >= CHACHA_BLOCK_SIZE) {
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chacha20_block_xor_neon(state, dst, src);
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chacha_block_xor_neon(state, dst, src, nrounds);
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bytes -= CHACHA_BLOCK_SIZE;
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src += CHACHA_BLOCK_SIZE;
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dst += CHACHA_BLOCK_SIZE;
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@ -60,14 +63,14 @@ static void chacha20_doneon(u32 *state, u8 *dst, const u8 *src,
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}
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if (bytes) {
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memcpy(buf, src, bytes);
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chacha20_block_xor_neon(state, buf, buf);
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chacha_block_xor_neon(state, buf, buf, nrounds);
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memcpy(dst, buf, bytes);
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}
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kernel_neon_end();
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}
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static int chacha20_neon_stream_xor(struct skcipher_request *req,
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struct chacha_ctx *ctx, u8 *iv)
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static int chacha_neon_stream_xor(struct skcipher_request *req,
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struct chacha_ctx *ctx, u8 *iv)
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{
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struct skcipher_walk walk;
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u32 state[16];
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@ -83,15 +86,15 @@ static int chacha20_neon_stream_xor(struct skcipher_request *req,
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if (nbytes < walk.total)
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nbytes = round_down(nbytes, walk.stride);
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chacha20_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
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nbytes);
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chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
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nbytes, ctx->nrounds);
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err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
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}
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return err;
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}
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static int chacha20_neon(struct skcipher_request *req)
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static int chacha_neon(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
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@ -99,10 +102,10 @@ static int chacha20_neon(struct skcipher_request *req)
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if (req->cryptlen <= CHACHA_BLOCK_SIZE || !may_use_simd())
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return crypto_chacha_crypt(req);
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return chacha20_neon_stream_xor(req, ctx, req->iv);
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return chacha_neon_stream_xor(req, ctx, req->iv);
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}
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static int xchacha20_neon(struct skcipher_request *req)
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static int xchacha_neon(struct skcipher_request *req)
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{
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struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
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@ -116,12 +119,13 @@ static int xchacha20_neon(struct skcipher_request *req)
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crypto_chacha_init(state, ctx, req->iv);
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kernel_neon_begin();
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hchacha20_block_neon(state, subctx.key);
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hchacha_block_neon(state, subctx.key, ctx->nrounds);
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kernel_neon_end();
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subctx.nrounds = ctx->nrounds;
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memcpy(&real_iv[0], req->iv + 24, 8);
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memcpy(&real_iv[8], req->iv + 16, 8);
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return chacha20_neon_stream_xor(req, &subctx, real_iv);
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return chacha_neon_stream_xor(req, &subctx, real_iv);
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}
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static struct skcipher_alg algs[] = {
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@ -139,8 +143,8 @@ static struct skcipher_alg algs[] = {
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.chunksize = CHACHA_BLOCK_SIZE,
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.walksize = 4 * CHACHA_BLOCK_SIZE,
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.setkey = crypto_chacha20_setkey,
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.encrypt = chacha20_neon,
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.decrypt = chacha20_neon,
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.encrypt = chacha_neon,
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.decrypt = chacha_neon,
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}, {
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.base.cra_name = "xchacha20",
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.base.cra_driver_name = "xchacha20-neon",
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@ -155,12 +159,12 @@ static struct skcipher_alg algs[] = {
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.chunksize = CHACHA_BLOCK_SIZE,
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.walksize = 4 * CHACHA_BLOCK_SIZE,
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.setkey = crypto_chacha20_setkey,
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.encrypt = xchacha20_neon,
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.decrypt = xchacha20_neon,
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.encrypt = xchacha_neon,
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.decrypt = xchacha_neon,
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}
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};
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static int __init chacha20_simd_mod_init(void)
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static int __init chacha_simd_mod_init(void)
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{
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if (!(elf_hwcap & HWCAP_ASIMD))
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return -ENODEV;
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@ -168,14 +172,15 @@ static int __init chacha20_simd_mod_init(void)
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return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
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}
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static void __exit chacha20_simd_mod_fini(void)
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static void __exit chacha_simd_mod_fini(void)
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{
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crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
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}
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module_init(chacha20_simd_mod_init);
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module_exit(chacha20_simd_mod_fini);
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module_init(chacha_simd_mod_init);
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module_exit(chacha_simd_mod_fini);
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MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (NEON accelerated)");
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MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS_CRYPTO("chacha20");
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