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 
write_blob(void * provctx,OSSL_CORE_BIO * cout,void * data,int len)29 static 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 
43 static OSSL_FUNC_encoder_newctx_fn key2blob_newctx;
44 static OSSL_FUNC_encoder_freectx_fn key2blob_freectx;
45 
key2blob_newctx(void * provctx)46 static void *key2blob_newctx(void *provctx)
47 {
48     return provctx;
49 }
50 
key2blob_freectx(void * vctx)51 static void key2blob_freectx(void *vctx)
52 {
53 }
54 
key2blob_check_selection(int selection,int selection_mask)55 static 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 
key2blob_encode(void * vctx,const void * key,int selection,OSSL_CORE_BIO * cout)88 static 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
175 MAKE_BLOB_ENCODER(ec, ec, PUBLIC_KEY);
176 # ifndef OPENSSL_NO_SM2
177 MAKE_BLOB_ENCODER(sm2, ec, PUBLIC_KEY);
178 # endif
179 #endif
180