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crypto: x86/chacha20 - add XChaCha20 support
Add an XChaCha20 implementation that is hooked up to the x86_64 SIMD implementations of ChaCha20. This can be used by Adiantum. An SSSE3 implementation of single-block HChaCha20 is also added so that XChaCha20 can use it rather than the generic implementation. This required refactoring the ChaCha permutation into its own function. 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
0f961f9f67
commit
4af7826187
3 changed files with 140 additions and 59 deletions
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@ -10,6 +10,7 @@
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*/
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#include <linux/linkage.h>
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#include <asm/frame.h>
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.section .rodata.cst16.ROT8, "aM", @progbits, 16
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.align 16
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@ -23,37 +24,24 @@ CTRINC: .octa 0x00000003000000020000000100000000
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.text
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ENTRY(chacha20_block_xor_ssse3)
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# %rdi: Input state matrix, s
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# %rsi: up to 1 data block output, o
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# %rdx: up to 1 data block input, i
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# %rcx: input/output length in bytes
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# This function encrypts one ChaCha20 block by loading the state matrix
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# in four SSE registers. It performs matrix operation on four words in
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# parallel, but requires shuffling to rearrange the words after each
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# round. 8/16-bit word rotation is done with the slightly better
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# performing SSSE3 byte shuffling, 7/12-bit word rotation uses
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# traditional shift+OR.
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# x0..3 = s0..3
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movdqa 0x00(%rdi),%xmm0
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movdqa 0x10(%rdi),%xmm1
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movdqa 0x20(%rdi),%xmm2
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movdqa 0x30(%rdi),%xmm3
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movdqa %xmm0,%xmm8
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movdqa %xmm1,%xmm9
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movdqa %xmm2,%xmm10
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movdqa %xmm3,%xmm11
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/*
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* chacha20_permute - permute one block
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*
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* Permute one 64-byte block where the state matrix is in %xmm0-%xmm3. This
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* function performs matrix operations on four words in parallel, but requires
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* shuffling to rearrange the words after each round. 8/16-bit word rotation is
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* done with the slightly better performing SSSE3 byte shuffling, 7/12-bit word
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* rotation uses traditional shift+OR.
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*
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* Clobbers: %ecx, %xmm4-%xmm7
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*/
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chacha20_permute:
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movdqa ROT8(%rip),%xmm4
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movdqa ROT16(%rip),%xmm5
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mov %rcx,%rax
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mov $10,%ecx
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.Ldoubleround:
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# x0 += x1, x3 = rotl32(x3 ^ x0, 16)
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paddd %xmm1,%xmm0
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pxor %xmm0,%xmm3
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@ -123,6 +111,29 @@ ENTRY(chacha20_block_xor_ssse3)
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dec %ecx
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jnz .Ldoubleround
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ret
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ENDPROC(chacha20_permute)
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ENTRY(chacha20_block_xor_ssse3)
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# %rdi: Input state matrix, s
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# %rsi: up to 1 data block output, o
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# %rdx: up to 1 data block input, i
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# %rcx: input/output length in bytes
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FRAME_BEGIN
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# x0..3 = s0..3
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movdqa 0x00(%rdi),%xmm0
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movdqa 0x10(%rdi),%xmm1
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movdqa 0x20(%rdi),%xmm2
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movdqa 0x30(%rdi),%xmm3
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movdqa %xmm0,%xmm8
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movdqa %xmm1,%xmm9
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movdqa %xmm2,%xmm10
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movdqa %xmm3,%xmm11
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mov %rcx,%rax
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call chacha20_permute
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# o0 = i0 ^ (x0 + s0)
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paddd %xmm8,%xmm0
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cmp $0x10,%rax
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@ -156,6 +167,7 @@ ENTRY(chacha20_block_xor_ssse3)
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movdqu %xmm0,0x30(%rsi)
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.Ldone:
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FRAME_END
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ret
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.Lxorpart:
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@ -189,6 +201,25 @@ ENTRY(chacha20_block_xor_ssse3)
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ENDPROC(chacha20_block_xor_ssse3)
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ENTRY(hchacha20_block_ssse3)
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# %rdi: Input state matrix, s
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# %rsi: output (8 32-bit words)
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FRAME_BEGIN
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movdqa 0x00(%rdi),%xmm0
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movdqa 0x10(%rdi),%xmm1
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movdqa 0x20(%rdi),%xmm2
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movdqa 0x30(%rdi),%xmm3
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call chacha20_permute
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movdqu %xmm0,0x00(%rsi)
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movdqu %xmm3,0x10(%rsi)
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FRAME_END
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ret
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ENDPROC(hchacha20_block_ssse3)
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ENTRY(chacha20_4block_xor_ssse3)
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# %rdi: Input state matrix, s
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# %rsi: up to 4 data blocks output, o
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@ -23,6 +23,7 @@ asmlinkage void chacha20_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
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unsigned int len);
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asmlinkage void chacha20_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
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unsigned int len);
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asmlinkage void hchacha20_block_ssse3(const u32 *state, u32 *out);
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#ifdef CONFIG_AS_AVX2
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asmlinkage void chacha20_2block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
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unsigned int len);
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@ -121,10 +122,9 @@ static void chacha20_dosimd(u32 *state, u8 *dst, const u8 *src,
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}
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}
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static int chacha20_simd(struct skcipher_request *req)
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static int chacha20_simd_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 crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
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struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
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u32 *state, state_buf[16 + 2] __aligned(8);
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struct skcipher_walk walk;
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int err;
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@ -132,14 +132,9 @@ static int chacha20_simd(struct skcipher_request *req)
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BUILD_BUG_ON(CHACHA20_STATE_ALIGN != 16);
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state = PTR_ALIGN(state_buf + 0, CHACHA20_STATE_ALIGN);
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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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err = skcipher_walk_virt(&walk, req, true);
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crypto_chacha_init(state, ctx, walk.iv);
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kernel_fpu_begin();
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crypto_chacha_init(state, ctx, iv);
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while (walk.nbytes > 0) {
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unsigned int nbytes = walk.nbytes;
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@ -153,26 +148,85 @@ static int chacha20_simd(struct skcipher_request *req)
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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_simd(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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int err;
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if (req->cryptlen <= CHACHA_BLOCK_SIZE || !irq_fpu_usable())
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return crypto_chacha_crypt(req);
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kernel_fpu_begin();
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err = chacha20_simd_stream_xor(req, ctx, req->iv);
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kernel_fpu_end();
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return err;
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}
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static int xchacha20_simd(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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struct chacha_ctx subctx;
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u32 *state, state_buf[16 + 2] __aligned(8);
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u8 real_iv[16];
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int err;
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if (req->cryptlen <= CHACHA_BLOCK_SIZE || !irq_fpu_usable())
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return crypto_xchacha_crypt(req);
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BUILD_BUG_ON(CHACHA20_STATE_ALIGN != 16);
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state = PTR_ALIGN(state_buf + 0, CHACHA20_STATE_ALIGN);
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crypto_chacha_init(state, ctx, req->iv);
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kernel_fpu_begin();
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hchacha20_block_ssse3(state, subctx.key);
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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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err = chacha20_simd_stream_xor(req, &subctx, real_iv);
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kernel_fpu_end();
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return err;
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}
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static struct skcipher_alg alg = {
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.base.cra_name = "chacha20",
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.base.cra_driver_name = "chacha20-simd",
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.base.cra_priority = 300,
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.base.cra_blocksize = 1,
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.base.cra_ctxsize = sizeof(struct chacha_ctx),
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.base.cra_module = THIS_MODULE,
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static struct skcipher_alg algs[] = {
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{
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.base.cra_name = "chacha20",
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.base.cra_driver_name = "chacha20-simd",
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.base.cra_priority = 300,
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.base.cra_blocksize = 1,
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.base.cra_ctxsize = sizeof(struct chacha_ctx),
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.base.cra_module = THIS_MODULE,
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.min_keysize = CHACHA_KEY_SIZE,
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.max_keysize = CHACHA_KEY_SIZE,
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.ivsize = CHACHA_IV_SIZE,
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.chunksize = CHACHA_BLOCK_SIZE,
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.setkey = crypto_chacha20_setkey,
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.encrypt = chacha20_simd,
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.decrypt = chacha20_simd,
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.min_keysize = CHACHA_KEY_SIZE,
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.max_keysize = CHACHA_KEY_SIZE,
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.ivsize = CHACHA_IV_SIZE,
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.chunksize = CHACHA_BLOCK_SIZE,
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.setkey = crypto_chacha20_setkey,
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.encrypt = chacha20_simd,
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.decrypt = chacha20_simd,
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}, {
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.base.cra_name = "xchacha20",
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.base.cra_driver_name = "xchacha20-simd",
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.base.cra_priority = 300,
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.base.cra_blocksize = 1,
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.base.cra_ctxsize = sizeof(struct chacha_ctx),
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.base.cra_module = THIS_MODULE,
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.min_keysize = CHACHA_KEY_SIZE,
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.max_keysize = CHACHA_KEY_SIZE,
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.ivsize = XCHACHA_IV_SIZE,
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.chunksize = CHACHA_BLOCK_SIZE,
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.setkey = crypto_chacha20_setkey,
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.encrypt = xchacha20_simd,
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.decrypt = xchacha20_simd,
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},
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};
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static int __init chacha20_simd_mod_init(void)
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@ -190,12 +244,12 @@ static int __init chacha20_simd_mod_init(void)
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boot_cpu_has(X86_FEATURE_AVX512BW); /* kmovq */
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#endif
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#endif
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return crypto_register_skcipher(&alg);
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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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{
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crypto_unregister_skcipher(&alg);
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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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@ -206,3 +260,5 @@ MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
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MODULE_DESCRIPTION("chacha20 cipher algorithm, SIMD accelerated");
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MODULE_ALIAS_CRYPTO("chacha20");
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MODULE_ALIAS_CRYPTO("chacha20-simd");
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MODULE_ALIAS_CRYPTO("xchacha20");
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MODULE_ALIAS_CRYPTO("xchacha20-simd");
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@ -1468,19 +1468,13 @@ config CRYPTO_CHACHA20
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in some performance-sensitive scenarios.
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config CRYPTO_CHACHA20_X86_64
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tristate "ChaCha20 cipher algorithm (x86_64/SSSE3/AVX2)"
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tristate "ChaCha stream cipher algorithms (x86_64/SSSE3/AVX2/AVX-512VL)"
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depends on X86 && 64BIT
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select CRYPTO_BLKCIPHER
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select CRYPTO_CHACHA20
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help
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ChaCha20 cipher algorithm, RFC7539.
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ChaCha20 is a 256-bit high-speed stream cipher designed by Daniel J.
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Bernstein and further specified in RFC7539 for use in IETF protocols.
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This is the x86_64 assembler implementation using SIMD instructions.
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See also:
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<http://cr.yp.to/chacha/chacha-20080128.pdf>
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SSSE3, AVX2, and AVX-512VL optimized implementations of the ChaCha20
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and XChaCha20 stream ciphers.
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config CRYPTO_SEED
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tristate "SEED cipher algorithm"
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