1/*
2 * Copyright 2020 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 <openssl/core.h>
11#include <openssl/core_names.h>
12#include <openssl/evp.h>
13#include <openssl/obj_mac.h>
14#include "internal/nelem.h"
15#include "crypto/rsa.h"
16
17static int meth2nid(const void *meth,
18                    int (*meth_is_a)(const void *meth, const char *name),
19                    const OSSL_ITEM *items, size_t items_n)
20{
21    size_t i;
22
23    if (meth != NULL)
24        for (i = 0; i < items_n; i++)
25            if (meth_is_a(meth, items[i].ptr))
26                return (int)items[i].id;
27    return NID_undef;
28}
29
30static const char *nid2name(int meth, const OSSL_ITEM *items, size_t items_n)
31{
32    size_t i;
33
34    for (i = 0; i < items_n; i++)
35        if (meth == (int)items[i].id)
36            return items[i].ptr;
37    return NULL;
38}
39
40/*
41 * The list of permitted hash functions are taken from
42 * https://tools.ietf.org/html/rfc8017#appendix-A.2.1:
43 *
44 * OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
45 *     { OID id-sha1       PARAMETERS NULL }|
46 *     { OID id-sha224     PARAMETERS NULL }|
47 *     { OID id-sha256     PARAMETERS NULL }|
48 *     { OID id-sha384     PARAMETERS NULL }|
49 *     { OID id-sha512     PARAMETERS NULL }|
50 *     { OID id-sha512-224 PARAMETERS NULL }|
51 *     { OID id-sha512-256 PARAMETERS NULL },
52 *     ...  -- Allows for future expansion --
53 * }
54 */
55static const OSSL_ITEM oaeppss_name_nid_map[] = {
56    { NID_sha1,         OSSL_DIGEST_NAME_SHA1         },
57    { NID_sha224,       OSSL_DIGEST_NAME_SHA2_224     },
58    { NID_sha256,       OSSL_DIGEST_NAME_SHA2_256     },
59    { NID_sha384,       OSSL_DIGEST_NAME_SHA2_384     },
60    { NID_sha512,       OSSL_DIGEST_NAME_SHA2_512     },
61    { NID_sha512_224,   OSSL_DIGEST_NAME_SHA2_512_224 },
62    { NID_sha512_256,   OSSL_DIGEST_NAME_SHA2_512_256 },
63};
64
65static int md_is_a(const void *md, const char *name)
66{
67    return EVP_MD_is_a(md, name);
68}
69
70int ossl_rsa_oaeppss_md2nid(const EVP_MD *md)
71{
72    return meth2nid(md, md_is_a,
73                    oaeppss_name_nid_map, OSSL_NELEM(oaeppss_name_nid_map));
74}
75
76const char *ossl_rsa_oaeppss_nid2name(int md)
77{
78    return nid2name(md, oaeppss_name_nid_map, OSSL_NELEM(oaeppss_name_nid_map));
79}
80
81const char *ossl_rsa_mgf_nid2name(int mgf)
82{
83    if (mgf == NID_mgf1)
84        return SN_mgf1;
85    return NULL;
86}
87