1/*
2 * Copyright 2021-2022 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/*
11 * Low level APIs are deprecated for public use, but still ok for internal use.
12 */
13#include "internal/deprecated.h"
14
15#include <openssl/core.h>
16#include <openssl/core_dispatch.h>
17#include <openssl/core_names.h>
18#include <openssl/params.h>
19#include <openssl/err.h>
20#include <openssl/evp.h>
21#include <openssl/ec.h>
22#include "internal/passphrase.h"
23#include "internal/nelem.h"
24#include "prov/implementations.h"
25#include "prov/bio.h"
26#include "prov/provider_ctx.h"
27#include "endecoder_local.h"
28
29static int write_blob(void *provctx, OSSL_CORE_BIO *cout,
30                      void *data, int len)
31{
32    BIO *out = ossl_bio_new_from_core_bio(provctx, cout);
33    int ret;
34
35    if (out == NULL)
36        return 0;
37    ret = BIO_write(out, data, len);
38
39    BIO_free(out);
40    return ret;
41}
42
43static OSSL_FUNC_encoder_newctx_fn key2blob_newctx;
44static OSSL_FUNC_encoder_freectx_fn key2blob_freectx;
45
46static void *key2blob_newctx(void *provctx)
47{
48    return provctx;
49}
50
51static void key2blob_freectx(void *vctx)
52{
53}
54
55static int key2blob_check_selection(int selection, int selection_mask)
56{
57    /*
58     * The selections are kinda sorta "levels", i.e. each selection given
59     * here is assumed to include those following.
60     */
61    int checks[] = {
62        OSSL_KEYMGMT_SELECT_PRIVATE_KEY,
63        OSSL_KEYMGMT_SELECT_PUBLIC_KEY,
64        OSSL_KEYMGMT_SELECT_ALL_PARAMETERS
65    };
66    size_t i;
67
68    /* The decoder implementations made here support guessing */
69    if (selection == 0)
70        return 1;
71
72    for (i = 0; i < OSSL_NELEM(checks); i++) {
73        int check1 = (selection & checks[i]) != 0;
74        int check2 = (selection_mask & checks[i]) != 0;
75
76        /*
77         * If the caller asked for the currently checked bit(s), return
78         * whether the decoder description says it's supported.
79         */
80        if (check1)
81            return check2;
82    }
83
84    /* This should be dead code, but just to be safe... */
85    return 0;
86}
87
88static int key2blob_encode(void *vctx, const void *key, int selection,
89                           OSSL_CORE_BIO *cout)
90{
91    int pubkey_len = 0, ok = 0;
92    unsigned char *pubkey = NULL;
93
94    pubkey_len = i2o_ECPublicKey(key, &pubkey);
95    if (pubkey_len > 0 && pubkey != NULL)
96        ok = write_blob(vctx, cout, pubkey, pubkey_len);
97    OPENSSL_free(pubkey);
98    return ok;
99}
100
101/*
102 * MAKE_BLOB_ENCODER() Makes an OSSL_DISPATCH table for a particular key->blob
103 * encoder
104 *
105 * impl:                The keytype to encode
106 * type:                The C structure type holding the key data
107 * selection_name:      The acceptable selections.  This translates into
108 *                      the macro EVP_PKEY_##selection_name.
109 *
110 * The selection is understood as a "level" rather than an exact set of
111 * requests from the caller.  The encoder has to decide what contents fit
112 * the encoded format.  For example, the EC public key blob will only contain
113 * the encoded public key itself, no matter if the selection bits include
114 * OSSL_KEYMGMT_SELECT_PARAMETERS or not.  However, if the selection includes
115 * OSSL_KEYMGMT_SELECT_PRIVATE_KEY, the same encoder will simply refuse to
116 * cooperate, because it cannot output the private key.
117 *
118 * EVP_PKEY_##selection_name are convenience macros that combine "typical"
119 * OSSL_KEYMGMT_SELECT_ macros for a certain type of EVP_PKEY content.
120 */
121#define MAKE_BLOB_ENCODER(impl, type, selection_name)                   \
122    static OSSL_FUNC_encoder_import_object_fn                           \
123    impl##2blob_import_object;                                          \
124    static OSSL_FUNC_encoder_free_object_fn impl##2blob_free_object;    \
125    static OSSL_FUNC_encoder_does_selection_fn                          \
126    impl##2blob_does_selection;                                         \
127    static OSSL_FUNC_encoder_encode_fn impl##2blob_encode;              \
128                                                                        \
129    static void *impl##2blob_import_object(void *ctx, int selection,    \
130                                           const OSSL_PARAM params[])   \
131    {                                                                   \
132        return ossl_prov_import_key(ossl_##impl##_keymgmt_functions,    \
133                                    ctx, selection, params);            \
134    }                                                                   \
135    static void impl##2blob_free_object(void *key)                      \
136    {                                                                   \
137        ossl_prov_free_key(ossl_##impl##_keymgmt_functions, key);       \
138    }                                                                   \
139    static int impl##2blob_does_selection(void *ctx, int selection)     \
140    {                                                                   \
141        return key2blob_check_selection(selection,                      \
142                                        EVP_PKEY_##selection_name);     \
143    }                                                                   \
144    static int impl##2blob_encode(void *vctx, OSSL_CORE_BIO *cout,      \
145                                  const void *key,                      \
146                                  const OSSL_PARAM key_abstract[],      \
147                                  int selection,                        \
148                                  OSSL_PASSPHRASE_CALLBACK *cb,         \
149                                  void *cbarg)                          \
150    {                                                                   \
151        /* We don't deal with abstract objects */                       \
152        if (key_abstract != NULL) {                                     \
153            ERR_raise(ERR_LIB_PROV, ERR_R_PASSED_INVALID_ARGUMENT);     \
154            return 0;                                                   \
155        }                                                               \
156        return key2blob_encode(vctx, key, selection, cout);             \
157    }                                                                   \
158    const OSSL_DISPATCH ossl_##impl##_to_blob_encoder_functions[] = {   \
159        { OSSL_FUNC_ENCODER_NEWCTX,                                     \
160          (void (*)(void))key2blob_newctx },                            \
161        { OSSL_FUNC_ENCODER_FREECTX,                                    \
162          (void (*)(void))key2blob_freectx },                           \
163        { OSSL_FUNC_ENCODER_DOES_SELECTION,                             \
164          (void (*)(void))impl##2blob_does_selection },                 \
165        { OSSL_FUNC_ENCODER_IMPORT_OBJECT,                              \
166          (void (*)(void))impl##2blob_import_object },                  \
167        { OSSL_FUNC_ENCODER_FREE_OBJECT,                                \
168          (void (*)(void))impl##2blob_free_object },                    \
169        { OSSL_FUNC_ENCODER_ENCODE,                                     \
170          (void (*)(void))impl##2blob_encode },                         \
171        { 0, NULL }                                                     \
172    }
173
174#ifndef OPENSSL_NO_EC
175MAKE_BLOB_ENCODER(ec, ec, PUBLIC_KEY);
176# ifndef OPENSSL_NO_SM2
177MAKE_BLOB_ENCODER(sm2, ec, PUBLIC_KEY);
178# endif
179#endif
180