1 /*
2  * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include "prov/ciphercommon.h"
11 #include "prov/ciphercommon_ccm.h"
12 
13 int ossl_ccm_generic_setiv(PROV_CCM_CTX *ctx, const unsigned char *nonce,
14                            size_t nlen, size_t mlen)
15 {
16     return CRYPTO_ccm128_setiv(&ctx->ccm_ctx, nonce, nlen, mlen) == 0;
17 }
18 
19 int ossl_ccm_generic_setaad(PROV_CCM_CTX *ctx, const unsigned char *aad,
20                             size_t alen)
21 {
22     CRYPTO_ccm128_aad(&ctx->ccm_ctx, aad, alen);
23     return 1;
24 }
25 
26 int ossl_ccm_generic_gettag(PROV_CCM_CTX *ctx, unsigned char *tag, size_t tlen)
27 {
28     return CRYPTO_ccm128_tag(&ctx->ccm_ctx, tag, tlen) > 0;
29 }
30 
31 int ossl_ccm_generic_auth_encrypt(PROV_CCM_CTX *ctx, const unsigned char *in,
32                                   unsigned char *out, size_t len,
33                                   unsigned char *tag, size_t taglen)
34 {
35     int rv;
36 
37     if (ctx->str != NULL)
38         rv = CRYPTO_ccm128_encrypt_ccm64(&ctx->ccm_ctx, in,
39                                          out, len, ctx->str) == 0;
40     else
41         rv = CRYPTO_ccm128_encrypt(&ctx->ccm_ctx, in, out, len) == 0;
42 
43     if (rv == 1 && tag != NULL)
44         rv = (CRYPTO_ccm128_tag(&ctx->ccm_ctx, tag, taglen) > 0);
45     return rv;
46 }
47 
48 int ossl_ccm_generic_auth_decrypt(PROV_CCM_CTX *ctx, const unsigned char *in,
49                                   unsigned char *out, size_t len,
50                                   unsigned char *expected_tag, size_t taglen)
51 {
52     int rv = 0;
53 
54     if (ctx->str != NULL)
55         rv = CRYPTO_ccm128_decrypt_ccm64(&ctx->ccm_ctx, in, out, len,
56                                          ctx->str) == 0;
57     else
58         rv = CRYPTO_ccm128_decrypt(&ctx->ccm_ctx, in, out, len) == 0;
59     if (rv) {
60         unsigned char tag[16];
61 
62         if (!CRYPTO_ccm128_tag(&ctx->ccm_ctx, tag, taglen)
63             || CRYPTO_memcmp(tag, expected_tag, taglen) != 0)
64             rv = 0;
65     }
66     if (rv == 0)
67         OPENSSL_cleanse(out, len);
68     return rv;
69 }
70