1 /*
2 * Copyright 2018-2021 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 <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 EVP_MAC_CTX_free(ctx->mac_ctx_init);
206 EVP_MAC_CTX_free(mac_ctx);
207 EVP_MAC_free(ctx->mac);
208 return 0;
209 }
210 EVP_MAC_CTX_free(mac_ctx);
211
212 ctx->final_ret = -1;
213 ctx->crypto_ok = 1;
214
215 return 1;
216 }
217
218 /*
219 * Copy an SIV128_CONTEXT object
220 */
ossl_siv128_copy_ctx(SIV128_CONTEXT * dest,SIV128_CONTEXT * src)221 int ossl_siv128_copy_ctx(SIV128_CONTEXT *dest, SIV128_CONTEXT *src)
222 {
223 memcpy(&dest->d, &src->d, sizeof(src->d));
224 if (dest->cipher_ctx == NULL) {
225 dest->cipher_ctx = EVP_CIPHER_CTX_new();
226 if (dest->cipher_ctx == NULL)
227 return 0;
228 }
229 if (!EVP_CIPHER_CTX_copy(dest->cipher_ctx, src->cipher_ctx))
230 return 0;
231 EVP_MAC_CTX_free(dest->mac_ctx_init);
232 dest->mac_ctx_init = EVP_MAC_CTX_dup(src->mac_ctx_init);
233 if (dest->mac_ctx_init == NULL)
234 return 0;
235 dest->mac = src->mac;
236 if (dest->mac != NULL)
237 EVP_MAC_up_ref(dest->mac);
238 return 1;
239 }
240
241 /*
242 * Provide any AAD. This can be called multiple times.
243 * Per RFC5297, the last piece of associated data
244 * is the nonce, but it's not treated special
245 */
ossl_siv128_aad(SIV128_CONTEXT * ctx,const unsigned char * aad,size_t len)246 int ossl_siv128_aad(SIV128_CONTEXT *ctx, const unsigned char *aad,
247 size_t len)
248 {
249 SIV_BLOCK mac_out;
250 size_t out_len = SIV_LEN;
251 EVP_MAC_CTX *mac_ctx;
252
253 siv128_dbl(&ctx->d);
254
255 if ((mac_ctx = EVP_MAC_CTX_dup(ctx->mac_ctx_init)) == NULL
256 || !EVP_MAC_update(mac_ctx, aad, len)
257 || !EVP_MAC_final(mac_ctx, mac_out.byte, &out_len,
258 sizeof(mac_out.byte))
259 || out_len != SIV_LEN) {
260 EVP_MAC_CTX_free(mac_ctx);
261 return 0;
262 }
263 EVP_MAC_CTX_free(mac_ctx);
264
265 siv128_xorblock(&ctx->d, &mac_out);
266
267 return 1;
268 }
269
270 /*
271 * Provide any data to be encrypted. This can be called once.
272 */
ossl_siv128_encrypt(SIV128_CONTEXT * ctx,const unsigned char * in,unsigned char * out,size_t len)273 int ossl_siv128_encrypt(SIV128_CONTEXT *ctx,
274 const unsigned char *in, unsigned char *out,
275 size_t len)
276 {
277 SIV_BLOCK q;
278
279 /* can only do one crypto operation */
280 if (ctx->crypto_ok == 0)
281 return 0;
282 ctx->crypto_ok--;
283
284 if (!siv128_do_s2v_p(ctx, &q, in, len))
285 return 0;
286
287 memcpy(ctx->tag.byte, &q, SIV_LEN);
288 q.byte[8] &= 0x7f;
289 q.byte[12] &= 0x7f;
290
291 if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q))
292 return 0;
293 ctx->final_ret = 0;
294 return len;
295 }
296
297 /*
298 * Provide any data to be decrypted. This can be called once.
299 */
ossl_siv128_decrypt(SIV128_CONTEXT * ctx,const unsigned char * in,unsigned char * out,size_t len)300 int ossl_siv128_decrypt(SIV128_CONTEXT *ctx,
301 const unsigned char *in, unsigned char *out,
302 size_t len)
303 {
304 unsigned char* p;
305 SIV_BLOCK t, q;
306 int i;
307
308 /* can only do one crypto operation */
309 if (ctx->crypto_ok == 0)
310 return 0;
311 ctx->crypto_ok--;
312
313 memcpy(&q, ctx->tag.byte, SIV_LEN);
314 q.byte[8] &= 0x7f;
315 q.byte[12] &= 0x7f;
316
317 if (!siv128_do_encrypt(ctx->cipher_ctx, out, in, len, &q)
318 || !siv128_do_s2v_p(ctx, &t, out, len))
319 return 0;
320
321 p = ctx->tag.byte;
322 for (i = 0; i < SIV_LEN; i++)
323 t.byte[i] ^= p[i];
324
325 if ((t.word[0] | t.word[1]) != 0) {
326 OPENSSL_cleanse(out, len);
327 return 0;
328 }
329 ctx->final_ret = 0;
330 return len;
331 }
332
333 /*
334 * Return the already calculated final result.
335 */
ossl_siv128_finish(SIV128_CONTEXT * ctx)336 int ossl_siv128_finish(SIV128_CONTEXT *ctx)
337 {
338 return ctx->final_ret;
339 }
340
341 /*
342 * Set the tag
343 */
ossl_siv128_set_tag(SIV128_CONTEXT * ctx,const unsigned char * tag,size_t len)344 int ossl_siv128_set_tag(SIV128_CONTEXT *ctx, const unsigned char *tag, size_t len)
345 {
346 if (len != SIV_LEN)
347 return 0;
348
349 /* Copy the tag from the supplied buffer */
350 memcpy(ctx->tag.byte, tag, len);
351 return 1;
352 }
353
354 /*
355 * Retrieve the calculated tag
356 */
ossl_siv128_get_tag(SIV128_CONTEXT * ctx,unsigned char * tag,size_t len)357 int ossl_siv128_get_tag(SIV128_CONTEXT *ctx, unsigned char *tag, size_t len)
358 {
359 if (len != SIV_LEN)
360 return 0;
361
362 /* Copy the tag into the supplied buffer */
363 memcpy(tag, ctx->tag.byte, len);
364 return 1;
365 }
366
367 /*
368 * Release all resources
369 */
ossl_siv128_cleanup(SIV128_CONTEXT * ctx)370 int ossl_siv128_cleanup(SIV128_CONTEXT *ctx)
371 {
372 if (ctx != NULL) {
373 EVP_CIPHER_CTX_free(ctx->cipher_ctx);
374 ctx->cipher_ctx = NULL;
375 EVP_MAC_CTX_free(ctx->mac_ctx_init);
376 ctx->mac_ctx_init = NULL;
377 EVP_MAC_free(ctx->mac);
378 ctx->mac = NULL;
379 OPENSSL_cleanse(&ctx->d, sizeof(ctx->d));
380 OPENSSL_cleanse(&ctx->tag, sizeof(ctx->tag));
381 ctx->final_ret = -1;
382 ctx->crypto_ok = 1;
383 }
384 return 1;
385 }
386
ossl_siv128_speed(SIV128_CONTEXT * ctx,int arg)387 int ossl_siv128_speed(SIV128_CONTEXT *ctx, int arg)
388 {
389 ctx->crypto_ok = (arg == 1) ? -1 : 1;
390 return 1;
391 }
392
393 #endif /* OPENSSL_NO_SIV */
394