1 /*
2 * Copyright 2018-2025 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 <stdlib.h>
12 #include <openssl/crypto.h>
13 #include <openssl/evp.h>
14 #include <openssl/core_names.h>
15 #include <openssl/params.h>
16 #include "internal/endian.h"
17 #include "crypto/modes.h"
18 #include "crypto/siv.h"
19
20 #ifndef OPENSSL_NO_SIV
21
rotl8(uint32_t x)22 __owur static ossl_inline uint32_t rotl8(uint32_t x)
23 {
24 return (x << 8) | (x >> 24);
25 }
26
rotr8(uint32_t x)27 __owur static ossl_inline uint32_t rotr8(uint32_t x)
28 {
29 return (x >> 8) | (x << 24);
30 }
31
byteswap8(uint64_t x)32 __owur static ossl_inline uint64_t byteswap8(uint64_t x)
33 {
34 uint32_t high = (uint32_t)(x >> 32);
35 uint32_t low = (uint32_t)x;
36
37 high = (rotl8(high) & 0x00ff00ff) | (rotr8(high) & 0xff00ff00);
38 low = (rotl8(low) & 0x00ff00ff) | (rotr8(low) & 0xff00ff00);
39 return ((uint64_t)low) << 32 | (uint64_t)high;
40 }
41
siv128_getword(SIV_BLOCK const * b,size_t i)42 __owur static ossl_inline uint64_t siv128_getword(SIV_BLOCK const *b, size_t i)
43 {
44 DECLARE_IS_ENDIAN;
45
46 if (IS_LITTLE_ENDIAN)
47 return byteswap8(b->word[i]);
48 return b->word[i];
49 }
50
siv128_putword(SIV_BLOCK * b,size_t i,uint64_t x)51 static ossl_inline void siv128_putword(SIV_BLOCK *b, size_t i, uint64_t x)
52 {
53 DECLARE_IS_ENDIAN;
54
55 if (IS_LITTLE_ENDIAN)
56 b->word[i] = byteswap8(x);
57 else
58 b->word[i] = x;
59 }
60
siv128_xorblock(SIV_BLOCK * x,SIV_BLOCK const * y)61 static ossl_inline void siv128_xorblock(SIV_BLOCK *x,
62 SIV_BLOCK const *y)
63 {
64 x->word[0] ^= y->word[0];
65 x->word[1] ^= y->word[1];
66 }
67
68 /*
69 * Doubles |b|, which is 16 bytes representing an element
70 * of GF(2**128) modulo the irreducible polynomial
71 * x**128 + x**7 + x**2 + x + 1.
72 * Assumes two's-complement arithmetic
73 */
siv128_dbl(SIV_BLOCK * b)74 static ossl_inline void siv128_dbl(SIV_BLOCK *b)
75 {
76 uint64_t high = siv128_getword(b, 0);
77 uint64_t low = siv128_getword(b, 1);
78 uint64_t high_carry = high & (((uint64_t)1) << 63);
79 uint64_t low_carry = low & (((uint64_t)1) << 63);
80 int64_t low_mask = -((int64_t)(high_carry >> 63)) & 0x87;
81 uint64_t high_mask = low_carry >> 63;
82
83 high = (high << 1) | high_mask;
84 low = (low << 1) ^ (uint64_t)low_mask;
85 siv128_putword(b, 0, high);
86 siv128_putword(b, 1, low);
87 }
88
siv128_do_s2v_p(SIV128_CONTEXT * ctx,SIV_BLOCK * out,unsigned char const * in,size_t len)89 __owur static ossl_inline int siv128_do_s2v_p(SIV128_CONTEXT *ctx, SIV_BLOCK *out,
90 unsigned char const* in, size_t len)
91 {
92 SIV_BLOCK t;
93 size_t out_len = sizeof(out->byte);
94 EVP_MAC_CTX *mac_ctx;
95 int ret = 0;
96
97 mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init);
98 if (mac_ctx == NULL)
99 return 0;
100
101 if (len >= SIV_LEN) {
102 if (!EVP_MAC_update(mac_ctx, in, len - SIV_LEN))
103 goto err;
104 memcpy(&t, in + (len-SIV_LEN), SIV_LEN);
105 siv128_xorblock(&t, &ctx->d);
106 if (!EVP_MAC_update(mac_ctx, t.byte, SIV_LEN))
107 goto err;
108 } else {
109 memset(&t, 0, sizeof(t));
110 memcpy(&t, in, len);
111 t.byte[len] = 0x80;
112 siv128_dbl(&ctx->d);
113 siv128_xorblock(&t, &ctx->d);
114 if (!EVP_MAC_update(mac_ctx, t.byte, SIV_LEN))
115 goto err;
116 }
117 if (!EVP_MAC_final(mac_ctx, out->byte, &out_len, sizeof(out->byte))
118 || out_len != SIV_LEN)
119 goto err;
120
121 ret = 1;
122
123 err:
124 EVP_MAC_CTX_free(mac_ctx);
125 return ret;
126 }
127
128
siv128_do_encrypt(EVP_CIPHER_CTX * ctx,unsigned char * out,unsigned char const * in,size_t len,SIV_BLOCK * icv)129 __owur static ossl_inline int siv128_do_encrypt(EVP_CIPHER_CTX *ctx, unsigned char *out,
130 unsigned char const *in, size_t len,
131 SIV_BLOCK *icv)
132 {
133 int out_len = (int)len;
134
135 if (!EVP_CipherInit_ex(ctx, NULL, NULL, NULL, icv->byte, 1))
136 return 0;
137 return EVP_EncryptUpdate(ctx, out, &out_len, in, out_len);
138 }
139
140 /*
141 * Create a new SIV128_CONTEXT
142 */
ossl_siv128_new(const unsigned char * key,int klen,EVP_CIPHER * cbc,EVP_CIPHER * ctr,OSSL_LIB_CTX * libctx,const char * propq)143 SIV128_CONTEXT *ossl_siv128_new(const unsigned char *key, int klen,
144 EVP_CIPHER *cbc, EVP_CIPHER *ctr,
145 OSSL_LIB_CTX *libctx, const char *propq)
146 {
147 SIV128_CONTEXT *ctx;
148 int ret;
149
150 if ((ctx = OPENSSL_malloc(sizeof(*ctx))) != NULL) {
151 ret = ossl_siv128_init(ctx, key, klen, cbc, ctr, libctx, propq);
152 if (ret)
153 return ctx;
154 OPENSSL_free(ctx);
155 }
156
157 return NULL;
158 }
159
160 /*
161 * Initialise an existing SIV128_CONTEXT
162 */
ossl_siv128_init(SIV128_CONTEXT * ctx,const unsigned char * key,int klen,const EVP_CIPHER * cbc,const EVP_CIPHER * ctr,OSSL_LIB_CTX * libctx,const char * propq)163 int ossl_siv128_init(SIV128_CONTEXT *ctx, const unsigned char *key, int klen,
164 const EVP_CIPHER *cbc, const EVP_CIPHER *ctr,
165 OSSL_LIB_CTX *libctx, const char *propq)
166 {
167 static const unsigned char zero[SIV_LEN] = { 0 };
168 size_t out_len = SIV_LEN;
169 EVP_MAC_CTX *mac_ctx = NULL;
170 OSSL_PARAM params[3];
171 const char *cbc_name;
172
173 if (ctx == NULL)
174 return 0;
175
176 memset(&ctx->d, 0, sizeof(ctx->d));
177 EVP_CIPHER_CTX_free(ctx->cipher_ctx);
178 EVP_MAC_CTX_free(ctx->mac_ctx_init);
179 EVP_MAC_free(ctx->mac);
180 ctx->mac = NULL;
181 ctx->cipher_ctx = NULL;
182 ctx->mac_ctx_init = NULL;
183
184 if (key == NULL || cbc == NULL || ctr == NULL)
185 return 0;
186
187 cbc_name = EVP_CIPHER_get0_name(cbc);
188 params[0] = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_CIPHER,
189 (char *)cbc_name, 0);
190 params[1] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
191 (void *)key, klen);
192 params[2] = OSSL_PARAM_construct_end();
193
194 if ((ctx->cipher_ctx = EVP_CIPHER_CTX_new()) == NULL
195 || (ctx->mac =
196 EVP_MAC_fetch(libctx, OSSL_MAC_NAME_CMAC, propq)) == NULL
197 || (ctx->mac_ctx_init = EVP_MAC_CTX_new(ctx->mac)) == NULL
198 || !EVP_MAC_CTX_set_params(ctx->mac_ctx_init, params)
199 || !EVP_EncryptInit_ex(ctx->cipher_ctx, ctr, NULL, key + klen, NULL)
200 || (mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init)) == NULL
201 || !EVP_MAC_update(mac_ctx, zero, sizeof(zero))
202 || !EVP_MAC_final(mac_ctx, ctx->d.byte, &out_len,
203 sizeof(ctx->d.byte))) {
204 EVP_CIPHER_CTX_free(ctx->cipher_ctx);
205 ctx->cipher_ctx = NULL;
206 EVP_MAC_CTX_free(ctx->mac_ctx_init);
207 ctx->mac_ctx_init = NULL;
208 EVP_MAC_CTX_free(mac_ctx);
209 EVP_MAC_free(ctx->mac);
210 ctx->mac = NULL;
211 return 0;
212 }
213 EVP_MAC_CTX_free(mac_ctx);
214
215 ctx->final_ret = -1;
216 ctx->crypto_ok = 1;
217
218 return 1;
219 }
220
221 /*
222 * Copy an SIV128_CONTEXT object
223 */
ossl_siv128_copy_ctx(SIV128_CONTEXT * dest,SIV128_CONTEXT * src)224 int ossl_siv128_copy_ctx(SIV128_CONTEXT *dest, SIV128_CONTEXT *src)
225 {
226 memcpy(&dest->d, &src->d, sizeof(src->d));
227 if (dest->cipher_ctx == NULL) {
228 dest->cipher_ctx = EVP_CIPHER_CTX_new();
229 if (dest->cipher_ctx == NULL)
230 return 0;
231 }
232 if (!EVP_CIPHER_CTX_copy(dest->cipher_ctx, src->cipher_ctx))
233 return 0;
234 EVP_MAC_CTX_free(dest->mac_ctx_init);
235 dest->mac_ctx_init = EVP_MAC_CTX_dup(src->mac_ctx_init);
236 if (dest->mac_ctx_init == NULL)
237 return 0;
238 dest->mac = src->mac;
239 if (dest->mac != NULL)
240 EVP_MAC_up_ref(dest->mac);
241 return 1;
242 }
243
244 /*
245 * Provide any AAD. This can be called multiple times.
246 * Per RFC5297, the last piece of associated data
247 * is the nonce, but it's not treated special
248 */
ossl_siv128_aad(SIV128_CONTEXT * ctx,const unsigned char * aad,size_t len)249 int ossl_siv128_aad(SIV128_CONTEXT *ctx, const unsigned char *aad,
250 size_t len)
251 {
252 SIV_BLOCK mac_out;
253 size_t out_len = SIV_LEN;
254 EVP_MAC_CTX *mac_ctx;
255
256 siv128_dbl(&ctx->d);
257
258 if ((mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init)) == NULL
259 || !EVP_MAC_update(mac_ctx, aad, len)
260 || !EVP_MAC_final(mac_ctx, mac_out.byte, &out_len,
261 sizeof(mac_out.byte))
262 || out_len != SIV_LEN) {
263 EVP_MAC_CTX_free(mac_ctx);
264 return 0;
265 }
266 EVP_MAC_CTX_free(mac_ctx);
267
268 siv128_xorblock(&ctx->d, &mac_out);
269
270 return 1;
271 }
272
273 /*
274 * Provide any data to be encrypted. This can be called once.
275 */
ossl_siv128_encrypt(SIV128_CONTEXT * ctx,const unsigned char * in,unsigned char * out,size_t len)276 int ossl_siv128_encrypt(SIV128_CONTEXT *ctx,
277 const unsigned char *in, unsigned char *out,
278 size_t len)
279 {
280 SIV_BLOCK q;
281
282 /* can only do one crypto operation */
283 if (ctx->crypto_ok == 0)
284 return 0;
285 ctx->crypto_ok--;
286
287 if (!siv128_do_s2v_p(ctx, &q, in, len))
288 return 0;
289
290 memcpy(ctx->tag.byte, &q, SIV_LEN);
291 q.byte[8] &= 0x7f;
292 q.byte[12] &= 0x7f;
293
294 if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q))
295 return 0;
296 ctx->final_ret = 0;
297 return 1;
298 }
299
300 /*
301 * Provide any data to be decrypted. This can be called once.
302 */
ossl_siv128_decrypt(SIV128_CONTEXT * ctx,const unsigned char * in,unsigned char * out,size_t len)303 int ossl_siv128_decrypt(SIV128_CONTEXT *ctx,
304 const unsigned char *in, unsigned char *out,
305 size_t len)
306 {
307 unsigned char* p;
308 SIV_BLOCK t, q;
309 int i;
310
311 /* can only do one crypto operation */
312 if (ctx->crypto_ok == 0)
313 return 0;
314 ctx->crypto_ok--;
315
316 memcpy(&q, ctx->tag.byte, SIV_LEN);
317 q.byte[8] &= 0x7f;
318 q.byte[12] &= 0x7f;
319
320 if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q)
321 || !siv128_do_s2v_p(ctx, &t, out, len))
322 return 0;
323
324 p = ctx->tag.byte;
325 for (i = 0; i < SIV_LEN; i++)
326 t.byte[i] ^= p[i];
327
328 if ((t.word[0] | t.word[1]) != 0) {
329 OPENSSL_cleanse(out, len);
330 return 0;
331 }
332 ctx->final_ret = 0;
333 return 1;
334 }
335
336 /*
337 * Return the already calculated final result.
338 */
ossl_siv128_finish(SIV128_CONTEXT * ctx)339 int ossl_siv128_finish(SIV128_CONTEXT *ctx)
340 {
341 return ctx->final_ret;
342 }
343
344 /*
345 * Set the tag
346 */
ossl_siv128_set_tag(SIV128_CONTEXT * ctx,const unsigned char * tag,size_t len)347 int ossl_siv128_set_tag(SIV128_CONTEXT *ctx, const unsigned char *tag, size_t len)
348 {
349 if (len != SIV_LEN)
350 return 0;
351
352 /* Copy the tag from the supplied buffer */
353 memcpy(ctx->tag.byte, tag, len);
354 return 1;
355 }
356
357 /*
358 * Retrieve the calculated tag
359 */
ossl_siv128_get_tag(SIV128_CONTEXT * ctx,unsigned char * tag,size_t len)360 int ossl_siv128_get_tag(SIV128_CONTEXT *ctx, unsigned char *tag, size_t len)
361 {
362 if (len != SIV_LEN)
363 return 0;
364
365 /* Copy the tag into the supplied buffer */
366 memcpy(tag, ctx->tag.byte, len);
367 return 1;
368 }
369
370 /*
371 * Release all resources
372 */
ossl_siv128_cleanup(SIV128_CONTEXT * ctx)373 int ossl_siv128_cleanup(SIV128_CONTEXT *ctx)
374 {
375 if (ctx != NULL) {
376 EVP_CIPHER_CTX_free(ctx->cipher_ctx);
377 ctx->cipher_ctx = NULL;
378 EVP_MAC_CTX_free(ctx->mac_ctx_init);
379 ctx->mac_ctx_init = NULL;
380 EVP_MAC_free(ctx->mac);
381 ctx->mac = NULL;
382 OPENSSL_cleanse(&ctx->d, sizeof(ctx->d));
383 OPENSSL_cleanse(&ctx->tag, sizeof(ctx->tag));
384 ctx->final_ret = -1;
385 ctx->crypto_ok = 1;
386 }
387 return 1;
388 }
389
ossl_siv128_speed(SIV128_CONTEXT * ctx,int arg)390 int ossl_siv128_speed(SIV128_CONTEXT *ctx, int arg)
391 {
392 ctx->crypto_ok = (arg == 1) ? -1 : 1;
393 return 1;
394 }
395
396 #endif /* OPENSSL_NO_SIV */
397