1 /*
2 * Copyright 2019-2023 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 * This file uses the low level AES functions (which are deprecated for
12 * non-internal use) in order to implement provider AES ciphers.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/proverr.h>
17 #include "cipher_aes.h"
18 #include "prov/providercommon.h"
19 #include "prov/implementations.h"
20
21 /* AES wrap with padding has IV length of 4, without padding 8 */
22 #define AES_WRAP_PAD_IVLEN 4
23 #define AES_WRAP_NOPAD_IVLEN 8
24
25 #define WRAP_FLAGS (PROV_CIPHER_FLAG_CUSTOM_IV)
26 #define WRAP_FLAGS_INV (WRAP_FLAGS | PROV_CIPHER_FLAG_INVERSE_CIPHER)
27
28 typedef size_t (*aeswrap_fn)(void *key, const unsigned char *iv,
29 unsigned char *out, const unsigned char *in,
30 size_t inlen, block128_f block);
31
32 static OSSL_FUNC_cipher_encrypt_init_fn aes_wrap_einit;
33 static OSSL_FUNC_cipher_decrypt_init_fn aes_wrap_dinit;
34 static OSSL_FUNC_cipher_update_fn aes_wrap_cipher;
35 static OSSL_FUNC_cipher_final_fn aes_wrap_final;
36 static OSSL_FUNC_cipher_freectx_fn aes_wrap_freectx;
37 static OSSL_FUNC_cipher_set_ctx_params_fn aes_wrap_set_ctx_params;
38
39 typedef struct prov_aes_wrap_ctx_st {
40 PROV_CIPHER_CTX base;
41 union {
42 OSSL_UNION_ALIGN;
43 AES_KEY ks;
44 } ks;
45 aeswrap_fn wrapfn;
46
47 } PROV_AES_WRAP_CTX;
48
aes_wrap_newctx(size_t kbits,size_t blkbits,size_t ivbits,unsigned int mode,uint64_t flags)49 static void *aes_wrap_newctx(size_t kbits, size_t blkbits,
50 size_t ivbits, unsigned int mode, uint64_t flags)
51 {
52 PROV_AES_WRAP_CTX *wctx;
53 PROV_CIPHER_CTX *ctx;
54
55 if (!ossl_prov_is_running())
56 return NULL;
57
58 wctx = OPENSSL_zalloc(sizeof(*wctx));
59 ctx = (PROV_CIPHER_CTX *)wctx;
60 if (ctx != NULL) {
61 ossl_cipher_generic_initkey(ctx, kbits, blkbits, ivbits, mode, flags,
62 NULL, NULL);
63 ctx->pad = (ctx->ivlen == AES_WRAP_PAD_IVLEN);
64 }
65 return wctx;
66 }
67
aes_wrap_dupctx(void * wctx)68 static void *aes_wrap_dupctx(void *wctx)
69 {
70 PROV_AES_WRAP_CTX *ctx = wctx;
71 PROV_AES_WRAP_CTX *dctx = wctx;
72
73 if (!ossl_prov_is_running())
74 return NULL;
75
76 if (ctx == NULL)
77 return NULL;
78 dctx = OPENSSL_memdup(ctx, sizeof(*ctx));
79
80 if (dctx != NULL && dctx->base.tlsmac != NULL && dctx->base.alloced) {
81 dctx->base.tlsmac = OPENSSL_memdup(dctx->base.tlsmac,
82 dctx->base.tlsmacsize);
83 if (dctx->base.tlsmac == NULL) {
84 OPENSSL_free(dctx);
85 dctx = NULL;
86 }
87 }
88 return dctx;
89 }
90
aes_wrap_freectx(void * vctx)91 static void aes_wrap_freectx(void *vctx)
92 {
93 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
94
95 ossl_cipher_generic_reset_ctx((PROV_CIPHER_CTX *)vctx);
96 OPENSSL_clear_free(wctx, sizeof(*wctx));
97 }
98
aes_wrap_init(void * vctx,const unsigned char * key,size_t keylen,const unsigned char * iv,size_t ivlen,const OSSL_PARAM params[],int enc)99 static int aes_wrap_init(void *vctx, const unsigned char *key,
100 size_t keylen, const unsigned char *iv,
101 size_t ivlen, const OSSL_PARAM params[], int enc)
102 {
103 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
104 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
105
106 if (!ossl_prov_is_running())
107 return 0;
108
109 ctx->enc = enc;
110 if (ctx->pad)
111 wctx->wrapfn = enc ? CRYPTO_128_wrap_pad : CRYPTO_128_unwrap_pad;
112 else
113 wctx->wrapfn = enc ? CRYPTO_128_wrap : CRYPTO_128_unwrap;
114
115 if (iv != NULL) {
116 if (!ossl_cipher_generic_initiv(ctx, iv, ivlen))
117 return 0;
118 }
119 if (key != NULL) {
120 int use_forward_transform;
121
122 if (keylen != ctx->keylen) {
123 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
124 return 0;
125 }
126 /*
127 * See SP800-38F : Section 5.1
128 * The forward and inverse transformations for the AES block
129 * cipher—called “cipher” and “inverse cipher” are informally known as
130 * the AES encryption and AES decryption functions, respectively.
131 * If the designated cipher function for a key-wrap algorithm is chosen
132 * to be the AES decryption function, then CIPH-1K will be the AES
133 * encryption function.
134 */
135 if (ctx->inverse_cipher == 0)
136 use_forward_transform = ctx->enc;
137 else
138 use_forward_transform = !ctx->enc;
139 if (use_forward_transform) {
140 AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks);
141 ctx->block = (block128_f)AES_encrypt;
142 } else {
143 AES_set_decrypt_key(key, keylen * 8, &wctx->ks.ks);
144 ctx->block = (block128_f)AES_decrypt;
145 }
146 }
147 return aes_wrap_set_ctx_params(ctx, params);
148 }
149
aes_wrap_einit(void * ctx,const unsigned char * key,size_t keylen,const unsigned char * iv,size_t ivlen,const OSSL_PARAM params[])150 static int aes_wrap_einit(void *ctx, const unsigned char *key, size_t keylen,
151 const unsigned char *iv, size_t ivlen,
152 const OSSL_PARAM params[])
153 {
154 return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 1);
155 }
156
aes_wrap_dinit(void * ctx,const unsigned char * key,size_t keylen,const unsigned char * iv,size_t ivlen,const OSSL_PARAM params[])157 static int aes_wrap_dinit(void *ctx, const unsigned char *key, size_t keylen,
158 const unsigned char *iv, size_t ivlen,
159 const OSSL_PARAM params[])
160 {
161 return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 0);
162 }
163
aes_wrap_cipher_internal(void * vctx,unsigned char * out,const unsigned char * in,size_t inlen)164 static int aes_wrap_cipher_internal(void *vctx, unsigned char *out,
165 const unsigned char *in, size_t inlen)
166 {
167 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
168 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
169 size_t rv;
170 int pad = ctx->pad;
171
172 /* No final operation so always return zero length */
173 if (in == NULL)
174 return 0;
175
176 /* Input length must always be non-zero */
177 if (inlen == 0) {
178 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
179 return -1;
180 }
181
182 /* If decrypting need at least 16 bytes and multiple of 8 */
183 if (!ctx->enc && (inlen < 16 || inlen & 0x7)) {
184 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
185 return -1;
186 }
187
188 /* If not padding input must be multiple of 8 */
189 if (!pad && inlen & 0x7) {
190 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH);
191 return -1;
192 }
193
194 if (out == NULL) {
195 if (ctx->enc) {
196 /* If padding round up to multiple of 8 */
197 if (pad)
198 inlen = (inlen + 7) / 8 * 8;
199 /* 8 byte prefix */
200 return inlen + 8;
201 } else {
202 /*
203 * If not padding output will be exactly 8 bytes smaller than
204 * input. If padding it will be at least 8 bytes smaller but we
205 * don't know how much.
206 */
207 return inlen - 8;
208 }
209 }
210
211 rv = wctx->wrapfn(&wctx->ks.ks, ctx->iv_set ? ctx->iv : NULL, out, in,
212 inlen, ctx->block);
213 if (!rv) {
214 ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
215 return -1;
216 }
217 if (rv > INT_MAX) {
218 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_OUTPUT_LENGTH);
219 return -1;
220 }
221 return (int)rv;
222 }
223
aes_wrap_final(void * vctx,unsigned char * out,size_t * outl,size_t outsize)224 static int aes_wrap_final(void *vctx, unsigned char *out, size_t *outl,
225 size_t outsize)
226 {
227 if (!ossl_prov_is_running())
228 return 0;
229
230 *outl = 0;
231 return 1;
232 }
233
aes_wrap_cipher(void * vctx,unsigned char * out,size_t * outl,size_t outsize,const unsigned char * in,size_t inl)234 static int aes_wrap_cipher(void *vctx,
235 unsigned char *out, size_t *outl, size_t outsize,
236 const unsigned char *in, size_t inl)
237 {
238 PROV_AES_WRAP_CTX *ctx = (PROV_AES_WRAP_CTX *)vctx;
239 size_t len;
240
241 if (!ossl_prov_is_running())
242 return 0;
243
244 if (inl == 0) {
245 *outl = 0;
246 return 1;
247 }
248
249 if (outsize < inl) {
250 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
251 return 0;
252 }
253
254 len = aes_wrap_cipher_internal(ctx, out, in, inl);
255 if (len <= 0)
256 return 0;
257
258 *outl = len;
259 return 1;
260 }
261
aes_wrap_set_ctx_params(void * vctx,const OSSL_PARAM params[])262 static int aes_wrap_set_ctx_params(void *vctx, const OSSL_PARAM params[])
263 {
264 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
265 const OSSL_PARAM *p;
266 size_t keylen = 0;
267
268 if (ossl_param_is_empty(params))
269 return 1;
270
271 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN);
272 if (p != NULL) {
273 if (!OSSL_PARAM_get_size_t(p, &keylen)) {
274 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
275 return 0;
276 }
277 if (ctx->keylen != keylen) {
278 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
279 return 0;
280 }
281 }
282 return 1;
283 }
284
285 #define IMPLEMENT_cipher(mode, fname, UCMODE, flags, kbits, blkbits, ivbits) \
286 static OSSL_FUNC_cipher_get_params_fn aes_##kbits##_##fname##_get_params; \
287 static int aes_##kbits##_##fname##_get_params(OSSL_PARAM params[]) \
288 { \
289 return ossl_cipher_generic_get_params(params, EVP_CIPH_##UCMODE##_MODE, \
290 flags, kbits, blkbits, ivbits); \
291 } \
292 static OSSL_FUNC_cipher_newctx_fn aes_##kbits##fname##_newctx; \
293 static void *aes_##kbits##fname##_newctx(void *provctx) \
294 { \
295 return aes_##mode##_newctx(kbits, blkbits, ivbits, \
296 EVP_CIPH_##UCMODE##_MODE, flags); \
297 } \
298 const OSSL_DISPATCH ossl_##aes##kbits##fname##_functions[] = { \
299 { OSSL_FUNC_CIPHER_NEWCTX, \
300 (void (*)(void))aes_##kbits##fname##_newctx }, \
301 { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))aes_##mode##_einit }, \
302 { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))aes_##mode##_dinit }, \
303 { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))aes_##mode##_cipher }, \
304 { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))aes_##mode##_final }, \
305 { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))aes_##mode##_freectx }, \
306 { OSSL_FUNC_CIPHER_DUPCTX, (void (*)(void))aes_##mode##_dupctx }, \
307 { OSSL_FUNC_CIPHER_GET_PARAMS, \
308 (void (*)(void))aes_##kbits##_##fname##_get_params }, \
309 { OSSL_FUNC_CIPHER_GETTABLE_PARAMS, \
310 (void (*)(void))ossl_cipher_generic_gettable_params }, \
311 { OSSL_FUNC_CIPHER_GET_CTX_PARAMS, \
312 (void (*)(void))ossl_cipher_generic_get_ctx_params }, \
313 { OSSL_FUNC_CIPHER_SET_CTX_PARAMS, \
314 (void (*)(void))aes_wrap_set_ctx_params }, \
315 { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS, \
316 (void (*)(void))ossl_cipher_generic_gettable_ctx_params }, \
317 { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS, \
318 (void (*)(void))ossl_cipher_generic_settable_ctx_params }, \
319 OSSL_DISPATCH_END \
320 }
321
322 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
323 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
324 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
325 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_PAD_IVLEN * 8);
326 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_PAD_IVLEN * 8);
327 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_PAD_IVLEN * 8);
328
329 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
330 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
331 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
332 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_PAD_IVLEN * 8);
333 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_PAD_IVLEN * 8);
334 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_PAD_IVLEN * 8);
335