xref: /freebsd/sys/crypto/chacha20/chacha-sw.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /* This file is in the public domain. */
2 
3 #include <sys/cdefs.h>
4 __FBSDID("$FreeBSD$");
5 
6 #include <crypto/chacha20/chacha.h>
7 #include <opencrypto/xform_enc.h>
8 
9 static int
10 chacha20_xform_setkey(u_int8_t **sched, u_int8_t *key, int len)
11 {
12 	struct chacha_ctx *ctx;
13 
14 	if (len != CHACHA_MINKEYLEN && len != 32)
15 		return (EINVAL);
16 
17 	ctx = malloc(sizeof(*ctx), M_CRYPTO_DATA, M_NOWAIT | M_ZERO);
18 	*sched = (void *)ctx;
19 	if (ctx == NULL)
20 		return (ENOMEM);
21 
22 	chacha_keysetup(ctx, key, len * 8);
23 	return (0);
24 }
25 
26 static void
27 chacha20_xform_reinit(caddr_t key, u_int8_t *iv)
28 {
29 	struct chacha_ctx *ctx;
30 
31 	ctx = (void *)key;
32 	chacha_ivsetup(ctx, iv + 8, iv);
33 }
34 
35 static void
36 chacha20_xform_zerokey(u_int8_t **sched)
37 {
38 	struct chacha_ctx *ctx;
39 
40 	ctx = (void *)*sched;
41 	explicit_bzero(ctx, sizeof(*ctx));
42 	free(ctx, M_CRYPTO_DATA);
43 	*sched = NULL;
44 }
45 
46 static void
47 chacha20_xform_crypt(caddr_t cctx, u_int8_t *bytes)
48 {
49 	struct chacha_ctx *ctx;
50 
51 	ctx = (void *)cctx;
52 	chacha_encrypt_bytes(ctx, bytes, bytes, 1);
53 }
54 
55 static void
56 chacha20_xform_crypt_multi(void *vctx, uint8_t *bytes, size_t len)
57 {
58 	struct chacha_ctx *ctx;
59 
60 	ctx = vctx;
61 	chacha_encrypt_bytes(ctx, bytes, bytes, len);
62 }
63 
64 struct enc_xform enc_xform_chacha20 = {
65 	.type = CRYPTO_CHACHA20,
66 	.name = "chacha20",
67 	.blocksize = 1,
68 	.ivsize = CHACHA_NONCELEN + CHACHA_CTRLEN,
69 	.minkey = CHACHA_MINKEYLEN,
70 	.maxkey = 32,
71 	.encrypt = chacha20_xform_crypt,
72 	.decrypt = chacha20_xform_crypt,
73 	.setkey = chacha20_xform_setkey,
74 	.zerokey = chacha20_xform_zerokey,
75 	.reinit = chacha20_xform_reinit,
76 	.encrypt_multi = chacha20_xform_crypt_multi,
77 	.decrypt_multi = chacha20_xform_crypt_multi,
78 };
79