1 /*
2  * Copyright 2020-2022 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
12  * internal use.
13  */
14 #include "internal/deprecated.h"
15 
16 #include <string.h>
17 
18 #include <openssl/core_dispatch.h>
19 #include <openssl/core_names.h>
20 #include <openssl/core_object.h>
21 #include <openssl/crypto.h>
22 #include <openssl/params.h>
23 #include <openssl/err.h>
24 #include <openssl/pem.h>         /* For public PVK functions */
25 #include <openssl/x509.h>
26 #include "internal/passphrase.h"
27 #include "crypto/pem.h"          /* For internal PVK and "blob" headers */
28 #include "crypto/rsa.h"
29 #include "prov/bio.h"
30 #include "prov/implementations.h"
31 #include "endecoder_local.h"
32 
33 struct pvk2key_ctx_st;            /* Forward declaration */
34 typedef int check_key_fn(void *, struct pvk2key_ctx_st *ctx);
35 typedef void adjust_key_fn(void *, struct pvk2key_ctx_st *ctx);
36 typedef void *b2i_PVK_of_bio_pw_fn(BIO *in, pem_password_cb *cb, void *u,
37                                    OSSL_LIB_CTX *libctx, const char *propq);
38 typedef void free_key_fn(void *);
39 struct keytype_desc_st {
40     int type;                 /* EVP key type */
41     const char *name;         /* Keytype */
42     const OSSL_DISPATCH *fns; /* Keymgmt (to pilfer functions from) */
43 
44     b2i_PVK_of_bio_pw_fn *read_private_key;
45     adjust_key_fn *adjust_key;
46     free_key_fn *free_key;
47 };
48 
49 static OSSL_FUNC_decoder_freectx_fn pvk2key_freectx;
50 static OSSL_FUNC_decoder_decode_fn pvk2key_decode;
51 static OSSL_FUNC_decoder_export_object_fn pvk2key_export_object;
52 
53 /*
54  * Context used for DER to key decoding.
55  */
56 struct pvk2key_ctx_st {
57     PROV_CTX *provctx;
58     const struct keytype_desc_st *desc;
59     /* The selection that is passed to der2key_decode() */
60     int selection;
61 };
62 
63 static struct pvk2key_ctx_st *
pvk2key_newctx(void * provctx,const struct keytype_desc_st * desc)64 pvk2key_newctx(void *provctx, const struct keytype_desc_st *desc)
65 {
66     struct pvk2key_ctx_st *ctx = OPENSSL_zalloc(sizeof(*ctx));
67 
68     if (ctx != NULL) {
69         ctx->provctx = provctx;
70         ctx->desc = desc;
71     }
72     return ctx;
73 }
74 
pvk2key_freectx(void * vctx)75 static void pvk2key_freectx(void *vctx)
76 {
77     struct pvk2key_ctx_st *ctx = vctx;
78 
79     OPENSSL_free(ctx);
80 }
81 
pvk2key_decode(void * vctx,OSSL_CORE_BIO * cin,int selection,OSSL_CALLBACK * data_cb,void * data_cbarg,OSSL_PASSPHRASE_CALLBACK * pw_cb,void * pw_cbarg)82 static int pvk2key_decode(void *vctx, OSSL_CORE_BIO *cin, int selection,
83                          OSSL_CALLBACK *data_cb, void *data_cbarg,
84                          OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)
85 {
86     struct pvk2key_ctx_st *ctx = vctx;
87     BIO *in = ossl_bio_new_from_core_bio(ctx->provctx, cin);
88     void *key = NULL;
89     int ok = 0;
90 
91     if (in == NULL)
92         return 0;
93 
94     ctx->selection = selection;
95 
96     if ((selection == 0
97          || (selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
98         && ctx->desc->read_private_key != NULL) {
99         struct ossl_passphrase_data_st pwdata;
100         int err, lib, reason;
101 
102         memset(&pwdata, 0, sizeof(pwdata));
103         if (!ossl_pw_set_ossl_passphrase_cb(&pwdata, pw_cb, pw_cbarg))
104             goto end;
105 
106         key = ctx->desc->read_private_key(in, ossl_pw_pvk_password, &pwdata,
107                                           PROV_LIBCTX_OF(ctx->provctx), NULL);
108 
109         /*
110          * Because the PVK API doesn't have a separate decrypt call, we need
111          * to check the error queue for certain well known errors that are
112          * considered fatal and which we pass through, while the rest gets
113          * thrown away.
114          */
115         err = ERR_peek_last_error();
116         lib = ERR_GET_LIB(err);
117         reason = ERR_GET_REASON(err);
118         if (lib == ERR_LIB_PEM
119             && (reason == PEM_R_BAD_PASSWORD_READ
120                 || reason == PEM_R_BAD_DECRYPT)) {
121             ERR_clear_last_mark();
122             goto end;
123         }
124 
125         if (selection != 0 && key == NULL)
126             goto next;
127     }
128 
129     if (key != NULL && ctx->desc->adjust_key != NULL)
130         ctx->desc->adjust_key(key, ctx);
131 
132  next:
133     /*
134      * Indicated that we successfully decoded something, or not at all.
135      * Ending up "empty handed" is not an error.
136      */
137     ok = 1;
138 
139     /*
140      * We free resources here so it's not held up during the callback, because
141      * we know the process is recursive and the allocated chunks of memory
142      * add up.
143      */
144     BIO_free(in);
145     in = NULL;
146 
147     if (key != NULL) {
148         OSSL_PARAM params[4];
149         int object_type = OSSL_OBJECT_PKEY;
150 
151         params[0] =
152             OSSL_PARAM_construct_int(OSSL_OBJECT_PARAM_TYPE, &object_type);
153         params[1] =
154             OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,
155                                              (char *)ctx->desc->name, 0);
156         /* The address of the key becomes the octet string */
157         params[2] =
158             OSSL_PARAM_construct_octet_string(OSSL_OBJECT_PARAM_REFERENCE,
159                                               &key, sizeof(key));
160         params[3] = OSSL_PARAM_construct_end();
161 
162         ok = data_cb(params, data_cbarg);
163     }
164 
165  end:
166     BIO_free(in);
167     ctx->desc->free_key(key);
168 
169     return ok;
170 }
171 
pvk2key_export_object(void * vctx,const void * reference,size_t reference_sz,OSSL_CALLBACK * export_cb,void * export_cbarg)172 static int pvk2key_export_object(void *vctx,
173                                 const void *reference, size_t reference_sz,
174                                 OSSL_CALLBACK *export_cb, void *export_cbarg)
175 {
176     struct pvk2key_ctx_st *ctx = vctx;
177     OSSL_FUNC_keymgmt_export_fn *export =
178         ossl_prov_get_keymgmt_export(ctx->desc->fns);
179     void *keydata;
180 
181     if (reference_sz == sizeof(keydata) && export != NULL) {
182         /* The contents of the reference is the address to our object */
183         keydata = *(void **)reference;
184 
185         return export(keydata, ctx->selection, export_cb, export_cbarg);
186     }
187     return 0;
188 }
189 
190 /* ---------------------------------------------------------------------- */
191 
192 #define dsa_private_key_bio     (b2i_PVK_of_bio_pw_fn *)b2i_DSA_PVK_bio_ex
193 #define dsa_adjust              NULL
194 #define dsa_free                (void (*)(void *))DSA_free
195 
196 /* ---------------------------------------------------------------------- */
197 
198 #define rsa_private_key_bio     (b2i_PVK_of_bio_pw_fn *)b2i_RSA_PVK_bio_ex
199 
rsa_adjust(void * key,struct pvk2key_ctx_st * ctx)200 static void rsa_adjust(void *key, struct pvk2key_ctx_st *ctx)
201 {
202     ossl_rsa_set0_libctx(key, PROV_LIBCTX_OF(ctx->provctx));
203 }
204 
205 #define rsa_free                (void (*)(void *))RSA_free
206 
207 /* ---------------------------------------------------------------------- */
208 
209 #define IMPLEMENT_MS(KEYTYPE, keytype)                                  \
210     static const struct keytype_desc_st                                 \
211     pvk2##keytype##_desc = {                                            \
212         EVP_PKEY_##KEYTYPE, #KEYTYPE,                                   \
213         ossl_##keytype##_keymgmt_functions,                             \
214         keytype##_private_key_bio,                                      \
215         keytype##_adjust,                                               \
216         keytype##_free                                                  \
217     };                                                                  \
218     static OSSL_FUNC_decoder_newctx_fn pvk2##keytype##_newctx;          \
219     static void *pvk2##keytype##_newctx(void *provctx)                  \
220     {                                                                   \
221         return pvk2key_newctx(provctx, &pvk2##keytype##_desc);          \
222     }                                                                   \
223     const OSSL_DISPATCH                                                 \
224     ossl_##pvk_to_##keytype##_decoder_functions[] = {                   \
225         { OSSL_FUNC_DECODER_NEWCTX,                                     \
226           (void (*)(void))pvk2##keytype##_newctx },                     \
227         { OSSL_FUNC_DECODER_FREECTX,                                    \
228           (void (*)(void))pvk2key_freectx },                            \
229         { OSSL_FUNC_DECODER_DECODE,                                     \
230           (void (*)(void))pvk2key_decode },                             \
231         { OSSL_FUNC_DECODER_EXPORT_OBJECT,                              \
232           (void (*)(void))pvk2key_export_object },                      \
233         { 0, NULL }                                                     \
234     }
235 
236 #ifndef OPENSSL_NO_DSA
237 IMPLEMENT_MS(DSA, dsa);
238 #endif
239 IMPLEMENT_MS(RSA, rsa);
240