1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | |
3 | #ifndef _CRYPTO_ECB_CBC_HELPER_H |
4 | #define _CRYPTO_ECB_CBC_HELPER_H |
5 | |
6 | #include <crypto/internal/skcipher.h> |
7 | #include <asm/fpu/api.h> |
8 | |
9 | /* |
10 | * Mode helpers to instantiate parameterized skcipher ECB/CBC modes without |
11 | * having to rely on indirect calls and retpolines. |
12 | */ |
13 | |
14 | #define ECB_WALK_START(req, bsize, fpu_blocks) do { \ |
15 | void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)); \ |
16 | const int __fpu_blocks = (fpu_blocks); \ |
17 | const int __bsize = (bsize); \ |
18 | struct skcipher_walk walk; \ |
19 | int err = skcipher_walk_virt(&walk, (req), false); \ |
20 | while (walk.nbytes > 0) { \ |
21 | unsigned int nbytes = walk.nbytes; \ |
22 | bool do_fpu = __fpu_blocks != -1 && \ |
23 | nbytes >= __fpu_blocks * __bsize; \ |
24 | const u8 *src = walk.src.virt.addr; \ |
25 | u8 *dst = walk.dst.virt.addr; \ |
26 | u8 __maybe_unused buf[(bsize)]; \ |
27 | if (do_fpu) kernel_fpu_begin() |
28 | |
29 | #define CBC_WALK_START(req, bsize, fpu_blocks) \ |
30 | ECB_WALK_START(req, bsize, fpu_blocks) |
31 | |
32 | #define ECB_WALK_ADVANCE(blocks) do { \ |
33 | dst += (blocks) * __bsize; \ |
34 | src += (blocks) * __bsize; \ |
35 | nbytes -= (blocks) * __bsize; \ |
36 | } while (0) |
37 | |
38 | #define ECB_BLOCK(blocks, func) do { \ |
39 | const int __blocks = (blocks); \ |
40 | if (do_fpu && __blocks < __fpu_blocks) { \ |
41 | kernel_fpu_end(); \ |
42 | do_fpu = false; \ |
43 | } \ |
44 | while (nbytes >= __blocks * __bsize) { \ |
45 | (func)(ctx, dst, src); \ |
46 | ECB_WALK_ADVANCE(blocks); \ |
47 | } \ |
48 | } while (0) |
49 | |
50 | #define CBC_ENC_BLOCK(func) do { \ |
51 | const u8 *__iv = walk.iv; \ |
52 | while (nbytes >= __bsize) { \ |
53 | crypto_xor_cpy(dst, src, __iv, __bsize); \ |
54 | (func)(ctx, dst, dst); \ |
55 | __iv = dst; \ |
56 | ECB_WALK_ADVANCE(1); \ |
57 | } \ |
58 | memcpy(walk.iv, __iv, __bsize); \ |
59 | } while (0) |
60 | |
61 | #define CBC_DEC_BLOCK(blocks, func) do { \ |
62 | const int __blocks = (blocks); \ |
63 | if (do_fpu && __blocks < __fpu_blocks) { \ |
64 | kernel_fpu_end(); \ |
65 | do_fpu = false; \ |
66 | } \ |
67 | while (nbytes >= __blocks * __bsize) { \ |
68 | const u8 *__iv = src + ((blocks) - 1) * __bsize; \ |
69 | if (dst == src) \ |
70 | __iv = memcpy(buf, __iv, __bsize); \ |
71 | (func)(ctx, dst, src); \ |
72 | crypto_xor(dst, walk.iv, __bsize); \ |
73 | memcpy(walk.iv, __iv, __bsize); \ |
74 | ECB_WALK_ADVANCE(blocks); \ |
75 | } \ |
76 | } while (0) |
77 | |
78 | #define ECB_WALK_END() \ |
79 | if (do_fpu) kernel_fpu_end(); \ |
80 | err = skcipher_walk_done(&walk, nbytes); \ |
81 | } \ |
82 | return err; \ |
83 | } while (0) |
84 | |
85 | #define CBC_WALK_END() ECB_WALK_END() |
86 | |
87 | #endif |
88 | |