diff options
| -rw-r--r-- | arch/x86/crypto/ecb_cbc_helpers.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/x86/crypto/ecb_cbc_helpers.h b/arch/x86/crypto/ecb_cbc_helpers.h new file mode 100644 index 000000000000..eaa15c7b29d6 --- /dev/null +++ b/arch/x86/crypto/ecb_cbc_helpers.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _CRYPTO_ECB_CBC_HELPER_H +#define _CRYPTO_ECB_CBC_HELPER_H + +#include <crypto/internal/skcipher.h> +#include <asm/fpu/api.h> + +/* + * Mode helpers to instantiate parameterized skcipher ECB/CBC modes without + * having to rely on indirect calls and retpolines. + */ + +#define ECB_WALK_START(req, bsize, fpu_blocks) do { \ + void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); \ + const int __bsize = (bsize); \ + struct skcipher_walk walk; \ + int err = skcipher_walk_virt(&walk, (req), false); \ + while (walk.nbytes > 0) { \ + unsigned int nbytes = walk.nbytes; \ + bool do_fpu = (fpu_blocks) != -1 && \ + nbytes >= (fpu_blocks) * __bsize; \ + const u8 *src = walk.src.virt.addr; \ + u8 *dst = walk.dst.virt.addr; \ + u8 __maybe_unused buf[(bsize)]; \ + if (do_fpu) kernel_fpu_begin() + +#define CBC_WALK_START(req, bsize, fpu_blocks) \ + ECB_WALK_START(req, bsize, fpu_blocks) + +#define ECB_WALK_ADVANCE(blocks) do { \ + dst += (blocks) * __bsize; \ + src += (blocks) * __bsize; \ + nbytes -= (blocks) * __bsize; \ +} while (0) + +#define ECB_BLOCK(blocks, func) do { \ + while (nbytes >= (blocks) * __bsize) { \ + (func)(ctx, dst, src); \ + ECB_WALK_ADVANCE(blocks); \ + } \ +} while (0) + +#define CBC_ENC_BLOCK(func) do { \ + const u8 *__iv = walk.iv; \ + while (nbytes >= __bsize) { \ + crypto_xor_cpy(dst, src, __iv, __bsize); \ + (func)(ctx, dst, dst); \ + __iv = dst; \ + ECB_WALK_ADVANCE(1); \ + } \ + memcpy(walk.iv, __iv, __bsize); \ +} while (0) + +#define CBC_DEC_BLOCK(blocks, func) do { \ + while (nbytes >= (blocks) * __bsize) { \ + const u8 *__iv = src + ((blocks) - 1) * __bsize; \ + if (dst == src) \ + __iv = memcpy(buf, __iv, __bsize); \ + (func)(ctx, dst, src); \ + crypto_xor(dst, walk.iv, __bsize); \ + memcpy(walk.iv, __iv, __bsize); \ + ECB_WALK_ADVANCE(blocks); \ + } \ +} while (0) + +#define ECB_WALK_END() \ + if (do_fpu) kernel_fpu_end(); \ + err = skcipher_walk_done(&walk, nbytes); \ + } \ + return err; \ +} while (0) + +#define CBC_WALK_END() ECB_WALK_END() + +#endif |