1/*
2 * Copyright 2019 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 "cipher_aes.h"
11#include "prov/providercommonerr.h"
12#include "prov/implementations.h"
13
14/* AES wrap with padding has IV length of 4, without padding 8 */
15#define AES_WRAP_PAD_IVLEN 4
16#define AES_WRAP_NOPAD_IVLEN 8
17
18/* TODO(3.0) Figure out what flags need to be passed */
19#define WRAP_FLAGS (EVP_CIPH_WRAP_MODE | EVP_CIPH_CUSTOM_IV \
20 | EVP_CIPH_ALWAYS_CALL_INIT)
21
22typedef size_t (*aeswrap_fn)(void *key, const unsigned char *iv,
23 unsigned char *out, const unsigned char *in,
24 size_t inlen, block128_f block);
25
26static OSSL_OP_cipher_encrypt_init_fn aes_wrap_einit;
27static OSSL_OP_cipher_decrypt_init_fn aes_wrap_dinit;
28static OSSL_OP_cipher_update_fn aes_wrap_cipher;
29static OSSL_OP_cipher_final_fn aes_wrap_final;
30static OSSL_OP_cipher_freectx_fn aes_wrap_freectx;
31
32typedef struct prov_aes_wrap_ctx_st {
33 PROV_CIPHER_CTX base;
34 union {
35 OSSL_UNION_ALIGN;
36 AES_KEY ks;
37 } ks;
38 aeswrap_fn wrapfn;
39
40} PROV_AES_WRAP_CTX;
41
42
43static void *aes_wrap_newctx(size_t kbits, size_t blkbits,
44 size_t ivbits, unsigned int mode, uint64_t flags)
45{
46 PROV_AES_WRAP_CTX *wctx = OPENSSL_zalloc(sizeof(*wctx));
47 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)wctx;
48
49 if (ctx != NULL) {
50 cipher_generic_initkey(ctx, kbits, blkbits, ivbits, mode, flags,
51 NULL, NULL);
52 ctx->pad = (ctx->ivlen == AES_WRAP_PAD_IVLEN);
53 }
54 return wctx;
55}
56
57static void aes_wrap_freectx(void *vctx)
58{
59 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
60
61 OPENSSL_clear_free(wctx, sizeof(*wctx));
62}
63
64static int aes_wrap_init(void *vctx, const unsigned char *key,
65 size_t keylen, const unsigned char *iv,
66 size_t ivlen, int enc)
67{
68 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
69 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
70
71 ctx->enc = enc;
72 ctx->block = enc ? (block128_f)AES_encrypt : (block128_f)AES_decrypt;
73 if (ctx->pad)
74 wctx->wrapfn = enc ? CRYPTO_128_wrap_pad : CRYPTO_128_unwrap_pad;
75 else
76 wctx->wrapfn = enc ? CRYPTO_128_wrap : CRYPTO_128_unwrap;
77
78 if (iv != NULL) {
79 if (!cipher_generic_initiv(ctx, iv, ivlen))
80 return 0;
81 }
82 if (key != NULL) {
83 if (keylen != ctx->keylen) {
84 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
85 return 0;
86 }
87 if (ctx->enc)
88 AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks);
89 else
90 AES_set_decrypt_key(key, keylen * 8, &wctx->ks.ks);
91 }
92 return 1;
93}
94
95static int aes_wrap_einit(void *ctx, const unsigned char *key, size_t keylen,
96 const unsigned char *iv, size_t ivlen)
97{
98 return aes_wrap_init(ctx, key, keylen, iv, ivlen, 1);
99}
100
101static int aes_wrap_dinit(void *ctx, const unsigned char *key, size_t keylen,
102 const unsigned char *iv, size_t ivlen)
103{
104 return aes_wrap_init(ctx, key, keylen, iv, ivlen, 0);
105}
106
107static int aes_wrap_cipher_internal(void *vctx, unsigned char *out,
108 const unsigned char *in, size_t inlen)
109{
110 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
111 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx;
112 size_t rv;
113 int pad = ctx->pad;
114
115 /* No final operation so always return zero length */
116 if (in == NULL)
117 return 0;
118
119 /* Input length must always be non-zero */
120 if (inlen == 0)
121 return -1;
122
123 /* If decrypting need at least 16 bytes and multiple of 8 */
124 if (!ctx->enc && (inlen < 16 || inlen & 0x7))
125 return -1;
126
127 /* If not padding input must be multiple of 8 */
128 if (!pad && inlen & 0x7)
129 return -1;
130
131 if (out == NULL) {
132 if (ctx->enc) {
133 /* If padding round up to multiple of 8 */
134 if (pad)
135 inlen = (inlen + 7) / 8 * 8;
136 /* 8 byte prefix */
137 return inlen + 8;
138 } else {
139 /*
140 * If not padding output will be exactly 8 bytes smaller than
141 * input. If padding it will be at least 8 bytes smaller but we
142 * don't know how much.
143 */
144 return inlen - 8;
145 }
146 }
147
148 rv = wctx->wrapfn(&wctx->ks.ks, ctx->iv_set ? ctx->iv : NULL, out, in,
149 inlen, ctx->block);
150 return rv ? (int)rv : -1;
151}
152
153static int aes_wrap_final(void *vctx, unsigned char *out, size_t *outl,
154 size_t outsize)
155{
156 *outl = 0;
157 return 1;
158}
159
160static int aes_wrap_cipher(void *vctx,
161 unsigned char *out, size_t *outl, size_t outsize,
162 const unsigned char *in, size_t inl)
163{
164 PROV_AES_WRAP_CTX *ctx = (PROV_AES_WRAP_CTX *)vctx;
165 size_t len;
166
167 if (inl == 0) {
168 *outl = 0;
169 return 1;
170 }
171
172 if (outsize < inl) {
173 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
174 return -1;
175 }
176
177 len = aes_wrap_cipher_internal(ctx, out, in, inl);
178 if (len == 0)
179 return -1;
180
181 *outl = len;
182 return 1;
183}
184
185static int aes_wrap_set_ctx_params(void *vctx, const OSSL_PARAM params[])
186{
187 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx;
188 const OSSL_PARAM *p;
189 size_t keylen = 0;
190
191 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN);
192 if (p != NULL) {
193 if (!OSSL_PARAM_get_size_t(p, &keylen)) {
194 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
195 return 0;
196 }
197 if (ctx->keylen != keylen) {
198 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
199 return 0;
200 }
201 }
202 return 1;
203}
204
205#define IMPLEMENT_cipher(mode, fname, UCMODE, flags, kbits, blkbits, ivbits) \
206 static OSSL_OP_cipher_get_params_fn aes_##kbits##_##fname##_get_params; \
207 static int aes_##kbits##_##fname##_get_params(OSSL_PARAM params[]) \
208 { \
209 return cipher_generic_get_params(params, EVP_CIPH_##UCMODE##_MODE, \
210 flags, kbits, blkbits, ivbits); \
211 } \
212 static OSSL_OP_cipher_newctx_fn aes_##kbits##fname##_newctx; \
213 static void *aes_##kbits##fname##_newctx(void *provctx) \
214 { \
215 return aes_##mode##_newctx(kbits, blkbits, ivbits, \
216 EVP_CIPH_##UCMODE##_MODE, flags); \
217 } \
218 const OSSL_DISPATCH aes##kbits##fname##_functions[] = { \
219 { OSSL_FUNC_CIPHER_NEWCTX, \
220 (void (*)(void))aes_##kbits##fname##_newctx }, \
221 { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))aes_##mode##_einit }, \
222 { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))aes_##mode##_dinit }, \
223 { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))aes_##mode##_cipher }, \
224 { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))aes_##mode##_final }, \
225 { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))aes_##mode##_freectx }, \
226 { OSSL_FUNC_CIPHER_GET_PARAMS, \
227 (void (*)(void))aes_##kbits##_##fname##_get_params }, \
228 { OSSL_FUNC_CIPHER_GETTABLE_PARAMS, \
229 (void (*)(void))cipher_generic_gettable_params }, \
230 { OSSL_FUNC_CIPHER_GET_CTX_PARAMS, \
231 (void (*)(void))cipher_generic_get_ctx_params }, \
232 { OSSL_FUNC_CIPHER_SET_CTX_PARAMS, \
233 (void (*)(void))aes_wrap_set_ctx_params }, \
234 { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS, \
235 (void (*)(void))cipher_generic_gettable_ctx_params }, \
236 { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS, \
237 (void (*)(void))cipher_generic_settable_ctx_params }, \
238 { 0, NULL } \
239 }
240
241IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_NOPAD_IVLEN * 8);
242IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_NOPAD_IVLEN * 8);
243IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_NOPAD_IVLEN * 8);
244IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_PAD_IVLEN * 8);
245IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_PAD_IVLEN * 8);
246IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_PAD_IVLEN * 8);
247