Line data Source code
1 : /*
2 : * Copyright (C) 2011-2012 Free Software Foundation, Inc.
3 : * Copyright (C) 2018 Red Hat, Inc.
4 : *
5 : * Author: Nikos Mavrogiannopoulos
6 : *
7 : * This file is part of GnuTLS.
8 : *
9 : * The GnuTLS is free software; you can redistribute it and/or
10 : * modify it under the terms of the GNU Lesser General Public License
11 : * as published by the Free Software Foundation; either version 2.1 of
12 : * the License, or (at your option) any later version.
13 : *
14 : * This library is distributed in the hope that it will be useful, but
15 : * WITHOUT ANY WARRANTY; without even the implied warranty of
16 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 : * Lesser General Public License for more details.
18 : *
19 : * You should have received a copy of the GNU Lesser General Public License
20 : * along with this program. If not, see <https://www.gnu.org/licenses/>
21 : *
22 : */
23 :
24 : /*
25 : * The following code is an implementation of the AES-128-GCM cipher
26 : * using intel's AES instruction set.
27 : */
28 :
29 : #include "errors.h"
30 : #include "gnutls_int.h"
31 : #include <gnutls/crypto.h>
32 : #include "errors.h"
33 : #include <aes-x86.h>
34 : #include <x86-common.h>
35 : #include <nettle/memxor.h>
36 : #include <byteswap.h>
37 :
38 : #define GCM_BLOCK_SIZE 16
39 :
40 : /* GCM mode */
41 :
42 : typedef struct {
43 : uint64_t hi, lo;
44 : } u128;
45 :
46 : /* This is the gcm128 structure used in openssl. It
47 : * is compatible with the included assembly code.
48 : */
49 : struct gcm128_context {
50 : union {
51 : uint64_t u[2];
52 : uint32_t d[4];
53 : uint8_t c[16];
54 : } Yi, EKi, EK0, len, Xi, H;
55 : u128 Htable[16];
56 : };
57 :
58 : struct aes_gcm_ctx {
59 : AES_KEY expanded_key;
60 : struct gcm128_context gcm;
61 : unsigned finished;
62 : unsigned auth_finished;
63 : };
64 :
65 : void gcm_init_clmul(u128 Htable[16], const uint64_t Xi[2]);
66 : void gcm_ghash_clmul(uint64_t Xi[2], const u128 Htable[16],
67 : const uint8_t * inp, size_t len);
68 : void gcm_gmult_clmul(uint64_t Xi[2], const u128 Htable[16]);
69 :
70 0 : static void aes_gcm_deinit(void *_ctx)
71 : {
72 0 : struct aes_gcm_ctx *ctx = _ctx;
73 :
74 0 : zeroize_temp_key(ctx, sizeof(*ctx));
75 0 : gnutls_free(ctx);
76 0 : }
77 :
78 : static int
79 0 : aes_gcm_cipher_init(gnutls_cipher_algorithm_t algorithm, void **_ctx,
80 : int enc)
81 : {
82 : /* we use key size to distinguish */
83 0 : if (algorithm != GNUTLS_CIPHER_AES_128_GCM &&
84 0 : algorithm != GNUTLS_CIPHER_AES_192_GCM &&
85 : algorithm != GNUTLS_CIPHER_AES_256_GCM)
86 : return GNUTLS_E_INVALID_REQUEST;
87 :
88 0 : *_ctx = gnutls_calloc(1, sizeof(struct aes_gcm_ctx));
89 0 : if (*_ctx == NULL) {
90 0 : gnutls_assert();
91 0 : return GNUTLS_E_MEMORY_ERROR;
92 : }
93 :
94 : return 0;
95 : }
96 :
97 : static int
98 0 : aes_gcm_cipher_setkey(void *_ctx, const void *userkey, size_t keysize)
99 : {
100 0 : struct aes_gcm_ctx *ctx = _ctx;
101 0 : int ret;
102 :
103 0 : CHECK_AES_KEYSIZE(keysize);
104 :
105 0 : ret =
106 0 : aesni_set_encrypt_key(userkey, keysize * 8,
107 0 : ALIGN16(&ctx->expanded_key));
108 0 : if (ret != 0)
109 0 : return gnutls_assert_val(GNUTLS_E_ENCRYPTION_FAILED);
110 :
111 0 : aesni_ecb_encrypt(ctx->gcm.H.c, ctx->gcm.H.c,
112 : GCM_BLOCK_SIZE, ALIGN16(&ctx->expanded_key), 1);
113 :
114 0 : ctx->gcm.H.u[0] = bswap_64(ctx->gcm.H.u[0]);
115 0 : ctx->gcm.H.u[1] = bswap_64(ctx->gcm.H.u[1]);
116 :
117 0 : gcm_init_clmul(ctx->gcm.Htable, ctx->gcm.H.u);
118 :
119 0 : return 0;
120 : }
121 :
122 0 : static int aes_gcm_setiv(void *_ctx, const void *iv, size_t iv_size)
123 : {
124 0 : struct aes_gcm_ctx *ctx = _ctx;
125 :
126 0 : if (iv_size != GCM_BLOCK_SIZE - 4)
127 0 : return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
128 :
129 0 : memset(ctx->gcm.Xi.c, 0, sizeof(ctx->gcm.Xi.c));
130 0 : memset(ctx->gcm.len.c, 0, sizeof(ctx->gcm.len.c));
131 :
132 0 : memcpy(ctx->gcm.Yi.c, iv, GCM_BLOCK_SIZE - 4);
133 0 : ctx->gcm.Yi.c[GCM_BLOCK_SIZE - 4] = 0;
134 0 : ctx->gcm.Yi.c[GCM_BLOCK_SIZE - 3] = 0;
135 0 : ctx->gcm.Yi.c[GCM_BLOCK_SIZE - 2] = 0;
136 0 : ctx->gcm.Yi.c[GCM_BLOCK_SIZE - 1] = 1;
137 :
138 0 : aesni_ecb_encrypt(ctx->gcm.Yi.c, ctx->gcm.EK0.c,
139 0 : GCM_BLOCK_SIZE, ALIGN16(&ctx->expanded_key), 1);
140 0 : ctx->gcm.Yi.c[GCM_BLOCK_SIZE - 1] = 2;
141 0 : ctx->finished = 0;
142 0 : ctx->auth_finished = 0;
143 0 : return 0;
144 : }
145 :
146 : static void
147 0 : gcm_ghash(struct aes_gcm_ctx *ctx, const uint8_t * src, size_t src_size)
148 : {
149 0 : size_t rest = src_size % GCM_BLOCK_SIZE;
150 0 : size_t aligned_size = src_size - rest;
151 :
152 0 : if (aligned_size > 0)
153 0 : gcm_ghash_clmul(ctx->gcm.Xi.u, ctx->gcm.Htable, src,
154 : aligned_size);
155 :
156 0 : if (rest > 0) {
157 0 : memxor(ctx->gcm.Xi.c, src + aligned_size, rest);
158 0 : gcm_gmult_clmul(ctx->gcm.Xi.u, ctx->gcm.Htable);
159 : }
160 0 : }
161 :
162 : static inline void
163 0 : ctr_encrypt_last(struct aes_gcm_ctx *ctx, const uint8_t * src,
164 : uint8_t * dst, size_t pos, size_t length)
165 : {
166 0 : uint8_t tmp[GCM_BLOCK_SIZE];
167 0 : uint8_t out[GCM_BLOCK_SIZE];
168 :
169 0 : memcpy(tmp, &src[pos], length);
170 0 : aesni_ctr32_encrypt_blocks(tmp, out, 1,
171 0 : ALIGN16(&ctx->expanded_key),
172 0 : ctx->gcm.Yi.c);
173 :
174 0 : memcpy(&dst[pos], out, length);
175 :
176 0 : }
177 :
178 : static int
179 0 : aes_gcm_encrypt(void *_ctx, const void *src, size_t src_size,
180 : void *dst, size_t length)
181 : {
182 0 : struct aes_gcm_ctx *ctx = _ctx;
183 0 : int blocks = src_size / GCM_BLOCK_SIZE;
184 0 : int exp_blocks = blocks * GCM_BLOCK_SIZE;
185 0 : int rest = src_size - (exp_blocks);
186 0 : uint32_t counter;
187 :
188 0 : if (unlikely(ctx->finished))
189 0 : return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
190 :
191 0 : if (blocks > 0) {
192 0 : aesni_ctr32_encrypt_blocks(src, dst,
193 : blocks,
194 0 : ALIGN16(&ctx->expanded_key),
195 0 : ctx->gcm.Yi.c);
196 :
197 0 : counter = _gnutls_read_uint32(ctx->gcm.Yi.c + 12);
198 0 : counter += blocks;
199 0 : _gnutls_write_uint32(counter, ctx->gcm.Yi.c + 12);
200 : }
201 :
202 0 : if (rest > 0) { /* last incomplete block */
203 0 : ctr_encrypt_last(ctx, src, dst, exp_blocks, rest);
204 0 : ctx->finished = 1;
205 : }
206 :
207 0 : gcm_ghash(ctx, dst, src_size);
208 0 : ctx->gcm.len.u[1] += src_size;
209 :
210 0 : return 0;
211 : }
212 :
213 : static int
214 0 : aes_gcm_decrypt(void *_ctx, const void *src, size_t src_size,
215 : void *dst, size_t dst_size)
216 : {
217 0 : struct aes_gcm_ctx *ctx = _ctx;
218 0 : int blocks = src_size / GCM_BLOCK_SIZE;
219 0 : int exp_blocks = blocks * GCM_BLOCK_SIZE;
220 0 : int rest = src_size - (exp_blocks);
221 0 : uint32_t counter;
222 :
223 0 : if (unlikely(ctx->finished))
224 0 : return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
225 :
226 0 : gcm_ghash(ctx, src, src_size);
227 0 : ctx->gcm.len.u[1] += src_size;
228 :
229 0 : if (blocks > 0) {
230 0 : aesni_ctr32_encrypt_blocks(src, dst,
231 : blocks,
232 0 : ALIGN16(&ctx->expanded_key),
233 0 : ctx->gcm.Yi.c);
234 :
235 0 : counter = _gnutls_read_uint32(ctx->gcm.Yi.c + 12);
236 0 : counter += blocks;
237 0 : _gnutls_write_uint32(counter, ctx->gcm.Yi.c + 12);
238 : }
239 :
240 0 : if (rest > 0) { /* last incomplete block */
241 0 : ctr_encrypt_last(ctx, src, dst, exp_blocks, rest);
242 0 : ctx->finished = 1;
243 : }
244 :
245 : return 0;
246 : }
247 :
248 0 : static int aes_gcm_auth(void *_ctx, const void *src, size_t src_size)
249 : {
250 0 : struct aes_gcm_ctx *ctx = _ctx;
251 :
252 0 : if (unlikely(ctx->auth_finished))
253 0 : return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
254 :
255 0 : gcm_ghash(ctx, src, src_size);
256 0 : ctx->gcm.len.u[0] += src_size;
257 :
258 0 : if (src_size % GCM_BLOCK_SIZE != 0)
259 0 : ctx->auth_finished = 1;
260 :
261 : return 0;
262 : }
263 :
264 :
265 0 : static void aes_gcm_tag(void *_ctx, void *tag, size_t tagsize)
266 : {
267 0 : struct aes_gcm_ctx *ctx = _ctx;
268 0 : uint8_t buffer[GCM_BLOCK_SIZE];
269 0 : uint64_t alen, clen;
270 :
271 0 : alen = ctx->gcm.len.u[0] * 8;
272 0 : clen = ctx->gcm.len.u[1] * 8;
273 :
274 0 : _gnutls_write_uint64(alen, buffer);
275 0 : _gnutls_write_uint64(clen, &buffer[8]);
276 :
277 0 : gcm_ghash_clmul(ctx->gcm.Xi.u, ctx->gcm.Htable, buffer,
278 : GCM_BLOCK_SIZE);
279 :
280 0 : ctx->gcm.Xi.u[0] ^= ctx->gcm.EK0.u[0];
281 0 : ctx->gcm.Xi.u[1] ^= ctx->gcm.EK0.u[1];
282 :
283 0 : memcpy(tag, ctx->gcm.Xi.c, MIN(GCM_BLOCK_SIZE, tagsize));
284 0 : }
285 :
286 : #include "aes-gcm-aead.h"
287 :
288 : const gnutls_crypto_cipher_st _gnutls_aes_gcm_pclmul = {
289 : .init = aes_gcm_cipher_init,
290 : .setkey = aes_gcm_cipher_setkey,
291 : .setiv = aes_gcm_setiv,
292 : .aead_encrypt = aes_gcm_aead_encrypt,
293 : .aead_decrypt = aes_gcm_aead_decrypt,
294 : .encrypt = aes_gcm_encrypt,
295 : .decrypt = aes_gcm_decrypt,
296 : .deinit = aes_gcm_deinit,
297 : .tag = aes_gcm_tag,
298 : .auth = aes_gcm_auth,
299 : };
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