1/*
2 * Copyright 2020-2021 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 <string.h>
11#include <openssl/crypto.h>
12#include <openssl/core_dispatch.h>
13#include <openssl/proverr.h>
14#include "prov/implementations.h"
15#include "prov/ciphercommon.h"
16#include "prov/providercommon.h"
17
18typedef struct prov_cipher_null_ctx_st {
19    int enc;
20    size_t tlsmacsize;
21    const unsigned char *tlsmac;
22} PROV_CIPHER_NULL_CTX;
23
24static OSSL_FUNC_cipher_newctx_fn null_newctx;
25static void *null_newctx(void *provctx)
26{
27    if (!ossl_prov_is_running())
28        return NULL;
29
30    return OPENSSL_zalloc(sizeof(PROV_CIPHER_NULL_CTX));
31}
32
33static OSSL_FUNC_cipher_freectx_fn null_freectx;
34static void null_freectx(void *vctx)
35{
36    OPENSSL_free(vctx);
37}
38
39static OSSL_FUNC_cipher_encrypt_init_fn null_einit;
40static int null_einit(void *vctx, const unsigned char *key, size_t keylen,
41                      const unsigned char *iv, size_t ivlen,
42                      const OSSL_PARAM params[])
43{
44    PROV_CIPHER_NULL_CTX *ctx = (PROV_CIPHER_NULL_CTX *)vctx;
45
46    if (!ossl_prov_is_running())
47        return 0;
48
49    ctx->enc = 1;
50    return 1;
51}
52
53static OSSL_FUNC_cipher_decrypt_init_fn null_dinit;
54static int null_dinit(void *vctx, const unsigned char *key, size_t keylen,
55                      const unsigned char *iv, size_t ivlen,
56                      const OSSL_PARAM params[])
57{
58    if (!ossl_prov_is_running())
59        return 0;
60
61    return 1;
62}
63
64static OSSL_FUNC_cipher_cipher_fn null_cipher;
65static int null_cipher(void *vctx, unsigned char *out, size_t *outl,
66                       size_t outsize, const unsigned char *in, size_t inl)
67{
68    PROV_CIPHER_NULL_CTX *ctx = (PROV_CIPHER_NULL_CTX *)vctx;
69
70    if (!ossl_prov_is_running())
71        return 0;
72
73    if (!ctx->enc && ctx->tlsmacsize > 0) {
74        /*
75         * TLS NULL cipher as per:
76         * https://tools.ietf.org/html/rfc5246#section-6.2.3.1
77         */
78        if (inl < ctx->tlsmacsize)
79            return 0;
80        ctx->tlsmac = in + inl - ctx->tlsmacsize;
81        inl -= ctx->tlsmacsize;
82    }
83    if (outsize < inl)
84        return 0;
85    if (in != out)
86        memcpy(out, in, inl);
87    *outl = inl;
88    return 1;
89}
90
91static OSSL_FUNC_cipher_final_fn null_final;
92static int null_final(void *vctx, unsigned char *out, size_t *outl,
93                      size_t outsize)
94{
95    if (!ossl_prov_is_running())
96        return 0;
97
98    *outl = 0;
99    return 1;
100}
101
102static OSSL_FUNC_cipher_get_params_fn null_get_params;
103static int null_get_params(OSSL_PARAM params[])
104{
105    return ossl_cipher_generic_get_params(params, 0, 0, 0, 8, 0);
106}
107
108static const OSSL_PARAM null_known_gettable_ctx_params[] = {
109    OSSL_PARAM_size_t(OSSL_CIPHER_PARAM_KEYLEN, NULL),
110    OSSL_PARAM_size_t(OSSL_CIPHER_PARAM_IVLEN, NULL),
111    { OSSL_CIPHER_PARAM_TLS_MAC, OSSL_PARAM_OCTET_PTR, NULL, 0, OSSL_PARAM_UNMODIFIED },
112    OSSL_PARAM_END
113};
114
115static OSSL_FUNC_cipher_gettable_ctx_params_fn null_gettable_ctx_params;
116static const OSSL_PARAM *null_gettable_ctx_params(ossl_unused void *cctx,
117                                                  ossl_unused void *provctx)
118{
119    return null_known_gettable_ctx_params;
120}
121
122static OSSL_FUNC_cipher_get_ctx_params_fn null_get_ctx_params;
123static int null_get_ctx_params(void *vctx, OSSL_PARAM params[])
124{
125    PROV_CIPHER_NULL_CTX *ctx = (PROV_CIPHER_NULL_CTX *)vctx;
126    OSSL_PARAM *p;
127
128    p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
129    if (p != NULL && !OSSL_PARAM_set_size_t(p, 0)) {
130        ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
131        return 0;
132    }
133    p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN);
134    if (p != NULL && !OSSL_PARAM_set_size_t(p, 0)) {
135        ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
136        return 0;
137    }
138    p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_TLS_MAC);
139    if (p != NULL
140        && !OSSL_PARAM_set_octet_ptr(p, ctx->tlsmac, ctx->tlsmacsize)) {
141        ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
142        return 0;
143    }
144    return 1;
145}
146
147static const OSSL_PARAM null_known_settable_ctx_params[] = {
148    OSSL_PARAM_size_t(OSSL_CIPHER_PARAM_TLS_MAC_SIZE, NULL),
149    OSSL_PARAM_END
150};
151
152static OSSL_FUNC_cipher_settable_ctx_params_fn null_settable_ctx_params;
153static const OSSL_PARAM *null_settable_ctx_params(ossl_unused void *cctx,
154                                                  ossl_unused void *provctx)
155{
156    return null_known_settable_ctx_params;
157}
158
159
160static OSSL_FUNC_cipher_set_ctx_params_fn null_set_ctx_params;
161static int null_set_ctx_params(void *vctx, const OSSL_PARAM params[])
162{
163    PROV_CIPHER_NULL_CTX *ctx = (PROV_CIPHER_NULL_CTX *)vctx;
164    const OSSL_PARAM *p;
165
166    p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_TLS_MAC_SIZE);
167    if (p != NULL) {
168        if (!OSSL_PARAM_get_size_t(p, &ctx->tlsmacsize)) {
169            ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
170            return 0;
171        }
172    }
173
174    return 1;
175}
176
177const OSSL_DISPATCH ossl_null_functions[] = {
178    { OSSL_FUNC_CIPHER_NEWCTX,
179      (void (*)(void)) null_newctx },
180    { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void)) null_freectx },
181    { OSSL_FUNC_CIPHER_DUPCTX, (void (*)(void)) null_newctx },
182    { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))null_einit },
183    { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))null_dinit },
184    { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))null_cipher },
185    { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))null_final },
186    { OSSL_FUNC_CIPHER_CIPHER, (void (*)(void))null_cipher },
187    { OSSL_FUNC_CIPHER_GET_PARAMS, (void (*)(void)) null_get_params },
188    { OSSL_FUNC_CIPHER_GETTABLE_PARAMS,
189        (void (*)(void))ossl_cipher_generic_gettable_params },
190    { OSSL_FUNC_CIPHER_GET_CTX_PARAMS, (void (*)(void))null_get_ctx_params },
191    { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS,
192      (void (*)(void))null_gettable_ctx_params },
193    { OSSL_FUNC_CIPHER_SET_CTX_PARAMS, (void (*)(void))null_set_ctx_params },
194    { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS,
195      (void (*)(void))null_settable_ctx_params },
196    { 0, NULL }
197};
198