xref: /freebsd/sys/crypto/chacha20/chacha-sw.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /* This file is in the public domain. */
2 
3 #include <sys/cdefs.h>
4 #include <crypto/chacha20/chacha.h>
5 #include <opencrypto/xform_enc.h>
6 
7 static int
8 chacha20_xform_setkey(void *ctx, const uint8_t *key, int len)
9 {
10 
11 	if (len != CHACHA_MINKEYLEN && len != 32)
12 		return (EINVAL);
13 
14 	chacha_keysetup(ctx, key, len * 8);
15 	return (0);
16 }
17 
18 static void
19 chacha20_xform_reinit(void *ctx, const uint8_t *iv, size_t ivlen)
20 {
21 	KASSERT(ivlen == CHACHA_NONCELEN + CHACHA_CTRLEN,
22 	    ("%s: invalid IV length", __func__));
23 	chacha_ivsetup(ctx, iv + 8, iv);
24 }
25 
26 static void
27 chacha20_xform_crypt(void *ctx, const uint8_t *in, uint8_t *out)
28 {
29 
30 	chacha_encrypt_bytes(ctx, in, out, CHACHA_BLOCKLEN);
31 }
32 
33 static void
34 chacha20_xform_crypt_multi(void *ctx, const uint8_t *in, uint8_t *out,
35     size_t len)
36 {
37 	KASSERT(len % CHACHA_BLOCKLEN == 0, ("%s: invalid length", __func__));
38 	chacha_encrypt_bytes(ctx, in, out, len);
39 }
40 
41 static void
42 chacha20_xform_crypt_last(void *ctx, const uint8_t *in, uint8_t *out,
43     size_t len)
44 {
45 
46 	chacha_encrypt_bytes(ctx, in, out, len);
47 }
48 
49 const struct enc_xform enc_xform_chacha20 = {
50 	.type = CRYPTO_CHACHA20,
51 	.name = "chacha20",
52 	.ctxsize = sizeof(struct chacha_ctx),
53 	.blocksize = 1,
54 	.native_blocksize = CHACHA_BLOCKLEN,
55 	.ivsize = CHACHA_NONCELEN + CHACHA_CTRLEN,
56 	.minkey = CHACHA_MINKEYLEN,
57 	.maxkey = 32,
58 	.setkey = chacha20_xform_setkey,
59 	.reinit = chacha20_xform_reinit,
60 	.encrypt = chacha20_xform_crypt,
61 	.decrypt = chacha20_xform_crypt,
62 	.encrypt_multi = chacha20_xform_crypt_multi,
63 	.decrypt_multi = chacha20_xform_crypt_multi,
64 	.encrypt_last = chacha20_xform_crypt_last,
65 	.decrypt_last = chacha20_xform_crypt_last,
66 };
67