2 * Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
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
11 * DES low level APIs are deprecated for public use, but still ok for internal
12 * use. We access the DES_set_odd_parity(3) function here.
14 #include "internal/deprecated.h"
20 #include <openssl/core_names.h>
21 #include <openssl/des.h>
22 #include <openssl/evp.h>
23 #include <openssl/kdf.h>
25 #include "internal/cryptlib.h"
26 #include "crypto/evp.h"
27 #include "internal/numbers.h"
28 #include "prov/implementations.h"
29 #include "prov/provider_ctx.h"
30 #include "prov/provider_util.h"
31 #include "prov/providercommonerr.h"
33 /* KRB5 KDF defined in RFC 3961, Section 5.1 */
35 static OSSL_FUNC_kdf_newctx_fn krb5kdf_new
;
36 static OSSL_FUNC_kdf_freectx_fn krb5kdf_free
;
37 static OSSL_FUNC_kdf_reset_fn krb5kdf_reset
;
38 static OSSL_FUNC_kdf_derive_fn krb5kdf_derive
;
39 static OSSL_FUNC_kdf_settable_ctx_params_fn krb5kdf_settable_ctx_params
;
40 static OSSL_FUNC_kdf_set_ctx_params_fn krb5kdf_set_ctx_params
;
41 static OSSL_FUNC_kdf_gettable_ctx_params_fn krb5kdf_gettable_ctx_params
;
42 static OSSL_FUNC_kdf_get_ctx_params_fn krb5kdf_get_ctx_params
;
44 static int KRB5KDF(const EVP_CIPHER
*cipher
, ENGINE
*engine
,
45 const unsigned char *key
, size_t key_len
,
46 const unsigned char *constant
, size_t constant_len
,
47 unsigned char *okey
, size_t okey_len
);
54 unsigned char *constant
;
58 static void *krb5kdf_new(void *provctx
)
62 if ((ctx
= OPENSSL_zalloc(sizeof(*ctx
))) == NULL
)
63 ERR_raise(ERR_LIB_PROV
, ERR_R_MALLOC_FAILURE
);
64 ctx
->provctx
= provctx
;
68 static void krb5kdf_free(void *vctx
)
70 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
78 static void krb5kdf_reset(void *vctx
)
80 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
82 ossl_prov_cipher_reset(&ctx
->cipher
);
83 OPENSSL_clear_free(ctx
->key
, ctx
->key_len
);
84 OPENSSL_clear_free(ctx
->constant
, ctx
->constant_len
);
85 memset(ctx
, 0, sizeof(*ctx
));
88 static int krb5kdf_set_membuf(unsigned char **dst
, size_t *dst_len
,
91 OPENSSL_clear_free(*dst
, *dst_len
);
93 return OSSL_PARAM_get_octet_string(p
, (void **)dst
, 0, dst_len
);
96 static int krb5kdf_derive(void *vctx
, unsigned char *key
,
99 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
100 const EVP_CIPHER
*cipher
= ossl_prov_cipher_cipher(&ctx
->cipher
);
101 ENGINE
*engine
= ossl_prov_cipher_engine(&ctx
->cipher
);
103 if (cipher
== NULL
) {
104 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_CIPHER
);
107 if (ctx
->key
== NULL
) {
108 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_KEY
);
111 if (ctx
->constant
== NULL
) {
112 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_CONSTANT
);
115 return KRB5KDF(cipher
, engine
, ctx
->key
, ctx
->key_len
,
116 ctx
->constant
, ctx
->constant_len
,
120 static int krb5kdf_set_ctx_params(void *vctx
, const OSSL_PARAM params
[])
123 KRB5KDF_CTX
*ctx
= vctx
;
124 OPENSSL_CTX
*provctx
= PROV_LIBRARY_CONTEXT_OF(ctx
->provctx
);
126 if (!ossl_prov_cipher_load_from_params(&ctx
->cipher
, params
, provctx
))
129 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KEY
)) != NULL
)
130 if (!krb5kdf_set_membuf(&ctx
->key
, &ctx
->key_len
, p
))
133 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_CONSTANT
))
135 if (!krb5kdf_set_membuf(&ctx
->constant
, &ctx
->constant_len
, p
))
141 static const OSSL_PARAM
*krb5kdf_settable_ctx_params(void)
143 static const OSSL_PARAM known_settable_ctx_params
[] = {
144 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES
, NULL
, 0),
145 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER
, NULL
, 0),
146 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY
, NULL
, 0),
147 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_CONSTANT
, NULL
, 0),
150 return known_settable_ctx_params
;
153 static int krb5kdf_get_ctx_params(void *vctx
, OSSL_PARAM params
[])
155 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
156 const EVP_CIPHER
*cipher
;
160 cipher
= ossl_prov_cipher_cipher(&ctx
->cipher
);
162 len
= EVP_CIPHER_key_length(cipher
);
164 len
= EVP_MAX_KEY_LENGTH
;
166 if ((p
= OSSL_PARAM_locate(params
, OSSL_KDF_PARAM_SIZE
)) != NULL
)
167 return OSSL_PARAM_set_size_t(p
, len
);
171 static const OSSL_PARAM
*krb5kdf_gettable_ctx_params(void)
173 static const OSSL_PARAM known_gettable_ctx_params
[] = {
174 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE
, NULL
),
177 return known_gettable_ctx_params
;
180 const OSSL_DISPATCH kdf_krb5kdf_functions
[] = {
181 { OSSL_FUNC_KDF_NEWCTX
, (void(*)(void))krb5kdf_new
},
182 { OSSL_FUNC_KDF_FREECTX
, (void(*)(void))krb5kdf_free
},
183 { OSSL_FUNC_KDF_RESET
, (void(*)(void))krb5kdf_reset
},
184 { OSSL_FUNC_KDF_DERIVE
, (void(*)(void))krb5kdf_derive
},
185 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS
,
186 (void(*)(void))krb5kdf_settable_ctx_params
},
187 { OSSL_FUNC_KDF_SET_CTX_PARAMS
,
188 (void(*)(void))krb5kdf_set_ctx_params
},
189 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS
,
190 (void(*)(void))krb5kdf_gettable_ctx_params
},
191 { OSSL_FUNC_KDF_GET_CTX_PARAMS
,
192 (void(*)(void))krb5kdf_get_ctx_params
},
196 #ifndef OPENSSL_NO_DES
198 * DES3 is a special case, it requires a random-to-key function and its
199 * input truncated to 21 bytes of the 24 produced by the cipher.
202 static int fixup_des3_key(unsigned char *key
)
204 unsigned char *cblock
;
207 for (i
= 2; i
>= 0; i
--) {
208 cblock
= &key
[i
* 8];
209 memmove(cblock
, &key
[i
* 7], 7);
211 for (j
= 0; j
< 7; j
++)
212 cblock
[7] |= (cblock
[j
] & 1) << (j
+ 1);
213 DES_set_odd_parity((DES_cblock
*)cblock
);
216 /* fail if keys are such that triple des degrades to single des */
217 if (CRYPTO_memcmp(&key
[0], &key
[8], 8) == 0 ||
218 CRYPTO_memcmp(&key
[8], &key
[16], 8) == 0) {
227 * N-fold(K) where blocksize is N, and constant_len is K
228 * Note: Here |= denotes concatenation
234 * s |= constant rot 13*(r-1))
238 * block += s[N(k-1)..(N-1)k] (one's complement addition)
240 * Optimizing for space we compute:
241 * for each l in L-1 -> 0:
242 * s[l] = (constant rot 13*(l/K))[l%k]
243 * block[l % N] += s[l] (with carry)
244 * finally add carry if any
246 static void n_fold(unsigned char *block
, unsigned int blocksize
,
247 const unsigned char *constant
, size_t constant_len
)
249 unsigned int tmp
, gcd
, remainder
, lcm
, carry
;
252 if (constant_len
== blocksize
) {
253 memcpy(block
, constant
, constant_len
);
257 /* Least Common Multiple of lengths: LCM(a,b)*/
259 remainder
= constant_len
;
260 /* Calculate Great Common Divisor first GCD(a,b) */
261 while (remainder
!= 0) {
262 tmp
= gcd
% remainder
;
266 /* resulting a is the GCD, LCM(a,b) = |a*b|/GCD(a,b) */
267 lcm
= blocksize
* constant_len
/ gcd
;
269 /* now spread out the bits */
270 memset(block
, 0, blocksize
);
272 /* last to first to be able to bring carry forward */
274 for (l
= lcm
- 1; l
>= 0; l
--) {
275 unsigned int rotbits
, rshift
, rbyte
;
277 /* destination byte in block is l % N */
279 /* Our virtual s buffer is R = L/K long (K = constant_len) */
280 /* So we rotate backwards from R-1 to 0 (none) rotations */
281 rotbits
= 13 * (l
/ constant_len
);
282 /* find the byte on s where rotbits falls onto */
283 rbyte
= l
- (rotbits
/ 8);
284 /* calculate how much shift on that byte */
285 rshift
= rotbits
& 0x07;
286 /* rbyte % constant_len gives us the unrotated byte in the
287 * constant buffer, get also the previous byte then
288 * appropriately shift them to get the rotated byte we need */
289 tmp
= (constant
[(rbyte
-1) % constant_len
] << (8 - rshift
)
290 | constant
[rbyte
% constant_len
] >> rshift
)
292 /* add with carry to any value placed by previous passes */
293 tmp
+= carry
+ block
[b
];
294 block
[b
] = tmp
& 0xff;
295 /* save any carry that may be left */
299 /* if any carry is left at the end, add it through the number */
300 for (b
= blocksize
- 1; b
>= 0 && carry
!= 0; b
--) {
302 block
[b
] = carry
& 0xff;
307 static int cipher_init(EVP_CIPHER_CTX
*ctx
,
308 const EVP_CIPHER
*cipher
, ENGINE
*engine
,
309 const unsigned char *key
, size_t key_len
)
313 ret
= EVP_EncryptInit_ex(ctx
, cipher
, engine
, key
, NULL
);
316 /* set the key len for the odd variable key len cipher */
317 klen
= EVP_CIPHER_CTX_key_length(ctx
);
318 if (key_len
!= (size_t)klen
) {
319 ret
= EVP_CIPHER_CTX_set_key_length(ctx
, key_len
);
323 /* we never want padding, either the length requested is a multiple of
324 * the cipher block size or we are passed a cipher that can cope with
325 * partial blocks via techniques like cipher text stealing */
326 ret
= EVP_CIPHER_CTX_set_padding(ctx
, 0);
334 static int KRB5KDF(const EVP_CIPHER
*cipher
, ENGINE
*engine
,
335 const unsigned char *key
, size_t key_len
,
336 const unsigned char *constant
, size_t constant_len
,
337 unsigned char *okey
, size_t okey_len
)
339 EVP_CIPHER_CTX
*ctx
= NULL
;
340 unsigned char block
[EVP_MAX_BLOCK_LENGTH
* 2];
341 unsigned char *plainblock
, *cipherblock
;
345 #ifndef OPENSSL_NO_DES
346 int des3_no_fixup
= 0;
350 if (key_len
!= okey_len
) {
351 #ifndef OPENSSL_NO_DES
352 /* special case for 3des, where the caller may be requesting
353 * the random raw key, instead of the fixed up key */
354 if (EVP_CIPHER_nid(cipher
) == NID_des_ede3_cbc
&&
355 key_len
== 24 && okey_len
== 21) {
359 ERR_raise(ERR_LIB_PROV
, PROV_R_WRONG_OUTPUT_BUFFER_SIZE
);
361 #ifndef OPENSSL_NO_DES
366 ctx
= EVP_CIPHER_CTX_new();
370 ret
= cipher_init(ctx
, cipher
, engine
, key
, key_len
);
374 /* Initialize input block */
375 blocksize
= EVP_CIPHER_CTX_block_size(ctx
);
377 if (constant_len
> blocksize
) {
378 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_CONSTANT_LENGTH
);
383 n_fold(block
, blocksize
, constant
, constant_len
);
385 cipherblock
= block
+ EVP_MAX_BLOCK_LENGTH
;
387 for (osize
= 0; osize
< okey_len
; osize
+= cipherlen
) {
390 ret
= EVP_EncryptUpdate(ctx
, cipherblock
, &olen
,
391 plainblock
, blocksize
);
395 ret
= EVP_EncryptFinal_ex(ctx
, cipherblock
, &olen
);
399 ERR_raise(ERR_LIB_PROV
, PROV_R_WRONG_FINAL_BLOCK_LENGTH
);
404 /* write cipherblock out */
405 if (cipherlen
> okey_len
- osize
)
406 cipherlen
= okey_len
- osize
;
407 memcpy(okey
+ osize
, cipherblock
, cipherlen
);
409 if (okey_len
> osize
+ cipherlen
) {
410 /* we need to reinitialize cipher context per spec */
411 ret
= EVP_CIPHER_CTX_reset(ctx
);
414 ret
= cipher_init(ctx
, cipher
, engine
, key
, key_len
);
418 /* also swap block offsets so last ciphertext becomes new
420 plainblock
= cipherblock
;
421 if (cipherblock
== block
) {
422 cipherblock
+= EVP_MAX_BLOCK_LENGTH
;
429 #ifndef OPENSSL_NO_DES
430 if (EVP_CIPHER_nid(cipher
) == NID_des_ede3_cbc
&& !des3_no_fixup
) {
431 ret
= fixup_des3_key(okey
);
433 ERR_raise(ERR_LIB_PROV
, PROV_R_FAILED_TO_GENERATE_KEY
);
442 EVP_CIPHER_CTX_free(ctx
);
443 OPENSSL_cleanse(block
, EVP_MAX_BLOCK_LENGTH
* 2);