Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
lib/crypto: aesgcm: Use GHASH library API
Make the AES-GCM library use the GHASH library instead of directly
calling gf128mul_lle(). This allows the architecture-optimized GHASH
implementations to be used, or the improved generic implementation if no
architecture-optimized implementation is usable.
Note: this means that <crypto/gcm.h> no longer needs to include
<crypto/gf128mul.h>. Remove that inclusion, and include
<crypto/gf128mul.h> explicitly from arch/x86/crypto/aesni-intel_glue.c
which previously was relying on the transitive inclusion.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260319061723.1140720-20-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
+32
-30
+1
arch/x86/crypto/aesni-intel_glue.c
+1
arch/x86/crypto/aesni-intel_glue.c
+2
-2
include/crypto/gcm.h
+2
-2
include/crypto/gcm.h
···
4
4
#include <linux/errno.h>
5
5
6
6
#include <crypto/aes.h>
7
-
#include <crypto/gf128mul.h>
7
+
#include <crypto/gf128hash.h>
8
8
9
9
#define GCM_AES_IV_SIZE 12
10
10
#define GCM_RFC4106_IV_SIZE 8
···
65
65
}
66
66
67
67
struct aesgcm_ctx {
68
-
be128 ghash_key;
68
+
struct ghash_key ghash_key;
69
69
struct aes_enckey aes_key;
70
70
unsigned int authsize;
71
71
};
+1
-1
lib/crypto/Kconfig
+1
-1
lib/crypto/Kconfig
+28
-27
lib/crypto/aesgcm.c
+28
-27
lib/crypto/aesgcm.c
···
5
5
* Copyright 2022 Google LLC
6
6
*/
7
7
8
-
#include <crypto/algapi.h>
9
8
#include <crypto/gcm.h>
10
-
#include <crypto/ghash.h>
9
+
#include <crypto/utils.h>
11
10
#include <linux/export.h>
12
11
#include <linux/module.h>
13
12
#include <asm/irqflags.h>
···
44
45
int aesgcm_expandkey(struct aesgcm_ctx *ctx, const u8 *key,
45
46
unsigned int keysize, unsigned int authsize)
46
47
{
47
-
u8 kin[AES_BLOCK_SIZE] = {};
48
+
u8 h[AES_BLOCK_SIZE] = {};
48
49
int ret;
49
50
50
51
ret = crypto_gcm_check_authsize(authsize) ?:
···
53
54
return ret;
54
55
55
56
ctx->authsize = authsize;
56
-
aesgcm_encrypt_block(&ctx->aes_key, &ctx->ghash_key, kin);
57
-
57
+
aesgcm_encrypt_block(&ctx->aes_key, h, h);
58
+
ghash_preparekey(&ctx->ghash_key, h);
59
+
memzero_explicit(h, sizeof(h));
58
60
return 0;
59
61
}
60
62
EXPORT_SYMBOL(aesgcm_expandkey);
61
-
62
-
static void aesgcm_ghash(be128 *ghash, const be128 *key, const void *src,
63
-
int len)
64
-
{
65
-
while (len > 0) {
66
-
crypto_xor((u8 *)ghash, src, min(len, GHASH_BLOCK_SIZE));
67
-
gf128mul_lle(ghash, key);
68
-
69
-
src += GHASH_BLOCK_SIZE;
70
-
len -= GHASH_BLOCK_SIZE;
71
-
}
72
-
}
73
63
74
64
/**
75
65
* aesgcm_mac - Generates the authentication tag using AES-GCM algorithm.
···
76
88
static void aesgcm_mac(const struct aesgcm_ctx *ctx, const u8 *src, int src_len,
77
89
const u8 *assoc, int assoc_len, __be32 *ctr, u8 *authtag)
78
90
{
79
-
be128 tail = { cpu_to_be64(assoc_len * 8), cpu_to_be64(src_len * 8) };
80
-
u8 buf[AES_BLOCK_SIZE];
81
-
be128 ghash = {};
91
+
static const u8 zeroes[GHASH_BLOCK_SIZE];
92
+
__be64 tail[2] = {
93
+
cpu_to_be64((u64)assoc_len * 8),
94
+
cpu_to_be64((u64)src_len * 8),
95
+
};
96
+
struct ghash_ctx ghash;
97
+
u8 ghash_out[AES_BLOCK_SIZE];
98
+
u8 enc_ctr[AES_BLOCK_SIZE];
82
99
83
-
aesgcm_ghash(&ghash, &ctx->ghash_key, assoc, assoc_len);
84
-
aesgcm_ghash(&ghash, &ctx->ghash_key, src, src_len);
85
-
aesgcm_ghash(&ghash, &ctx->ghash_key, &tail, sizeof(tail));
100
+
ghash_init(&ghash, &ctx->ghash_key);
101
+
102
+
ghash_update(&ghash, assoc, assoc_len);
103
+
ghash_update(&ghash, zeroes, -assoc_len & (GHASH_BLOCK_SIZE - 1));
104
+
105
+
ghash_update(&ghash, src, src_len);
106
+
ghash_update(&ghash, zeroes, -src_len & (GHASH_BLOCK_SIZE - 1));
107
+
108
+
ghash_update(&ghash, (const u8 *)&tail, sizeof(tail));
109
+
110
+
ghash_final(&ghash, ghash_out);
86
111
87
112
ctr[3] = cpu_to_be32(1);
88
-
aesgcm_encrypt_block(&ctx->aes_key, buf, ctr);
89
-
crypto_xor_cpy(authtag, buf, (u8 *)&ghash, ctx->authsize);
113
+
aesgcm_encrypt_block(&ctx->aes_key, enc_ctr, ctr);
114
+
crypto_xor_cpy(authtag, ghash_out, enc_ctr, ctx->authsize);
90
115
91
-
memzero_explicit(&ghash, sizeof(ghash));
92
-
memzero_explicit(buf, sizeof(buf));
116
+
memzero_explicit(ghash_out, sizeof(ghash_out));
117
+
memzero_explicit(enc_ctr, sizeof(enc_ctr));
93
118
}
94
119
95
120
static void aesgcm_crypt(const struct aesgcm_ctx *ctx, u8 *dst, const u8 *src,