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/providercommon.h"
32 #include "prov/providercommonerr.h"
34 /* KRB5 KDF defined in RFC 3961, Section 5.1 */
36 static OSSL_FUNC_kdf_newctx_fn krb5kdf_new
;
37 static OSSL_FUNC_kdf_freectx_fn krb5kdf_free
;
38 static OSSL_FUNC_kdf_reset_fn krb5kdf_reset
;
39 static OSSL_FUNC_kdf_derive_fn krb5kdf_derive
;
40 static OSSL_FUNC_kdf_settable_ctx_params_fn krb5kdf_settable_ctx_params
;
41 static OSSL_FUNC_kdf_set_ctx_params_fn krb5kdf_set_ctx_params
;
42 static OSSL_FUNC_kdf_gettable_ctx_params_fn krb5kdf_gettable_ctx_params
;
43 static OSSL_FUNC_kdf_get_ctx_params_fn krb5kdf_get_ctx_params
;
45 static int KRB5KDF(const EVP_CIPHER
*cipher
, ENGINE
*engine
,
46 const unsigned char *key
, size_t key_len
,
47 const unsigned char *constant
, size_t constant_len
,
48 unsigned char *okey
, size_t okey_len
);
55 unsigned char *constant
;
59 static void *krb5kdf_new(void *provctx
)
63 if (!ossl_prov_is_running())
66 if ((ctx
= OPENSSL_zalloc(sizeof(*ctx
))) == NULL
)
67 ERR_raise(ERR_LIB_PROV
, ERR_R_MALLOC_FAILURE
);
68 ctx
->provctx
= provctx
;
72 static void krb5kdf_free(void *vctx
)
74 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
82 static void krb5kdf_reset(void *vctx
)
84 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
85 void *provctx
= ctx
->provctx
;
87 ossl_prov_cipher_reset(&ctx
->cipher
);
88 OPENSSL_clear_free(ctx
->key
, ctx
->key_len
);
89 OPENSSL_clear_free(ctx
->constant
, ctx
->constant_len
);
90 memset(ctx
, 0, sizeof(*ctx
));
91 ctx
->provctx
= provctx
;
94 static int krb5kdf_set_membuf(unsigned char **dst
, size_t *dst_len
,
97 OPENSSL_clear_free(*dst
, *dst_len
);
99 return OSSL_PARAM_get_octet_string(p
, (void **)dst
, 0, dst_len
);
102 static int krb5kdf_derive(void *vctx
, unsigned char *key
,
105 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
106 const EVP_CIPHER
*cipher
;
109 if (!ossl_prov_is_running())
112 cipher
= ossl_prov_cipher_cipher(&ctx
->cipher
);
113 if (cipher
== NULL
) {
114 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_CIPHER
);
117 if (ctx
->key
== NULL
) {
118 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_KEY
);
121 if (ctx
->constant
== NULL
) {
122 ERR_raise(ERR_LIB_PROV
, PROV_R_MISSING_CONSTANT
);
125 engine
= ossl_prov_cipher_engine(&ctx
->cipher
);
126 return KRB5KDF(cipher
, engine
, ctx
->key
, ctx
->key_len
,
127 ctx
->constant
, ctx
->constant_len
,
131 static int krb5kdf_set_ctx_params(void *vctx
, const OSSL_PARAM params
[])
134 KRB5KDF_CTX
*ctx
= vctx
;
135 OSSL_LIB_CTX
*provctx
= PROV_LIBRARY_CONTEXT_OF(ctx
->provctx
);
137 if (!ossl_prov_cipher_load_from_params(&ctx
->cipher
, params
, provctx
))
140 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_KEY
)) != NULL
)
141 if (!krb5kdf_set_membuf(&ctx
->key
, &ctx
->key_len
, p
))
144 if ((p
= OSSL_PARAM_locate_const(params
, OSSL_KDF_PARAM_CONSTANT
))
146 if (!krb5kdf_set_membuf(&ctx
->constant
, &ctx
->constant_len
, p
))
152 static const OSSL_PARAM
*krb5kdf_settable_ctx_params(ossl_unused
void *provctx
)
154 static const OSSL_PARAM known_settable_ctx_params
[] = {
155 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES
, NULL
, 0),
156 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER
, NULL
, 0),
157 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY
, NULL
, 0),
158 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_CONSTANT
, NULL
, 0),
161 return known_settable_ctx_params
;
164 static int krb5kdf_get_ctx_params(void *vctx
, OSSL_PARAM params
[])
166 KRB5KDF_CTX
*ctx
= (KRB5KDF_CTX
*)vctx
;
167 const EVP_CIPHER
*cipher
;
171 cipher
= ossl_prov_cipher_cipher(&ctx
->cipher
);
173 len
= EVP_CIPHER_key_length(cipher
);
175 len
= EVP_MAX_KEY_LENGTH
;
177 if ((p
= OSSL_PARAM_locate(params
, OSSL_KDF_PARAM_SIZE
)) != NULL
)
178 return OSSL_PARAM_set_size_t(p
, len
);
182 static const OSSL_PARAM
*krb5kdf_gettable_ctx_params(ossl_unused
void *provctx
)
184 static const OSSL_PARAM known_gettable_ctx_params
[] = {
185 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE
, NULL
),
188 return known_gettable_ctx_params
;
191 const OSSL_DISPATCH ossl_kdf_krb5kdf_functions
[] = {
192 { OSSL_FUNC_KDF_NEWCTX
, (void(*)(void))krb5kdf_new
},
193 { OSSL_FUNC_KDF_FREECTX
, (void(*)(void))krb5kdf_free
},
194 { OSSL_FUNC_KDF_RESET
, (void(*)(void))krb5kdf_reset
},
195 { OSSL_FUNC_KDF_DERIVE
, (void(*)(void))krb5kdf_derive
},
196 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS
,
197 (void(*)(void))krb5kdf_settable_ctx_params
},
198 { OSSL_FUNC_KDF_SET_CTX_PARAMS
,
199 (void(*)(void))krb5kdf_set_ctx_params
},
200 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS
,
201 (void(*)(void))krb5kdf_gettable_ctx_params
},
202 { OSSL_FUNC_KDF_GET_CTX_PARAMS
,
203 (void(*)(void))krb5kdf_get_ctx_params
},
207 #ifndef OPENSSL_NO_DES
209 * DES3 is a special case, it requires a random-to-key function and its
210 * input truncated to 21 bytes of the 24 produced by the cipher.
213 static int fixup_des3_key(unsigned char *key
)
215 unsigned char *cblock
;
218 for (i
= 2; i
>= 0; i
--) {
219 cblock
= &key
[i
* 8];
220 memmove(cblock
, &key
[i
* 7], 7);
222 for (j
= 0; j
< 7; j
++)
223 cblock
[7] |= (cblock
[j
] & 1) << (j
+ 1);
224 DES_set_odd_parity((DES_cblock
*)cblock
);
227 /* fail if keys are such that triple des degrades to single des */
228 if (CRYPTO_memcmp(&key
[0], &key
[8], 8) == 0 ||
229 CRYPTO_memcmp(&key
[8], &key
[16], 8) == 0) {
238 * N-fold(K) where blocksize is N, and constant_len is K
239 * Note: Here |= denotes concatenation
245 * s |= constant rot 13*(r-1))
249 * block += s[N(k-1)..(N-1)k] (one's complement addition)
251 * Optimizing for space we compute:
252 * for each l in L-1 -> 0:
253 * s[l] = (constant rot 13*(l/K))[l%k]
254 * block[l % N] += s[l] (with carry)
255 * finally add carry if any
257 static void n_fold(unsigned char *block
, unsigned int blocksize
,
258 const unsigned char *constant
, size_t constant_len
)
260 unsigned int tmp
, gcd
, remainder
, lcm
, carry
;
263 if (constant_len
== blocksize
) {
264 memcpy(block
, constant
, constant_len
);
268 /* Least Common Multiple of lengths: LCM(a,b)*/
270 remainder
= constant_len
;
271 /* Calculate Great Common Divisor first GCD(a,b) */
272 while (remainder
!= 0) {
273 tmp
= gcd
% remainder
;
277 /* resulting a is the GCD, LCM(a,b) = |a*b|/GCD(a,b) */
278 lcm
= blocksize
* constant_len
/ gcd
;
280 /* now spread out the bits */
281 memset(block
, 0, blocksize
);
283 /* last to first to be able to bring carry forward */
285 for (l
= lcm
- 1; l
>= 0; l
--) {
286 unsigned int rotbits
, rshift
, rbyte
;
288 /* destination byte in block is l % N */
290 /* Our virtual s buffer is R = L/K long (K = constant_len) */
291 /* So we rotate backwards from R-1 to 0 (none) rotations */
292 rotbits
= 13 * (l
/ constant_len
);
293 /* find the byte on s where rotbits falls onto */
294 rbyte
= l
- (rotbits
/ 8);
295 /* calculate how much shift on that byte */
296 rshift
= rotbits
& 0x07;
297 /* rbyte % constant_len gives us the unrotated byte in the
298 * constant buffer, get also the previous byte then
299 * appropriately shift them to get the rotated byte we need */
300 tmp
= (constant
[(rbyte
-1) % constant_len
] << (8 - rshift
)
301 | constant
[rbyte
% constant_len
] >> rshift
)
303 /* add with carry to any value placed by previous passes */
304 tmp
+= carry
+ block
[b
];
305 block
[b
] = tmp
& 0xff;
306 /* save any carry that may be left */
310 /* if any carry is left at the end, add it through the number */
311 for (b
= blocksize
- 1; b
>= 0 && carry
!= 0; b
--) {
313 block
[b
] = carry
& 0xff;
318 static int cipher_init(EVP_CIPHER_CTX
*ctx
,
319 const EVP_CIPHER
*cipher
, ENGINE
*engine
,
320 const unsigned char *key
, size_t key_len
)
324 ret
= EVP_EncryptInit_ex(ctx
, cipher
, engine
, key
, NULL
);
327 /* set the key len for the odd variable key len cipher */
328 klen
= EVP_CIPHER_CTX_key_length(ctx
);
329 if (key_len
!= (size_t)klen
) {
330 ret
= EVP_CIPHER_CTX_set_key_length(ctx
, key_len
);
334 /* we never want padding, either the length requested is a multiple of
335 * the cipher block size or we are passed a cipher that can cope with
336 * partial blocks via techniques like cipher text stealing */
337 ret
= EVP_CIPHER_CTX_set_padding(ctx
, 0);
345 static int KRB5KDF(const EVP_CIPHER
*cipher
, ENGINE
*engine
,
346 const unsigned char *key
, size_t key_len
,
347 const unsigned char *constant
, size_t constant_len
,
348 unsigned char *okey
, size_t okey_len
)
350 EVP_CIPHER_CTX
*ctx
= NULL
;
351 unsigned char block
[EVP_MAX_BLOCK_LENGTH
* 2];
352 unsigned char *plainblock
, *cipherblock
;
356 #ifndef OPENSSL_NO_DES
357 int des3_no_fixup
= 0;
361 if (key_len
!= okey_len
) {
362 #ifndef OPENSSL_NO_DES
363 /* special case for 3des, where the caller may be requesting
364 * the random raw key, instead of the fixed up key */
365 if (EVP_CIPHER_nid(cipher
) == NID_des_ede3_cbc
&&
366 key_len
== 24 && okey_len
== 21) {
370 ERR_raise(ERR_LIB_PROV
, PROV_R_WRONG_OUTPUT_BUFFER_SIZE
);
372 #ifndef OPENSSL_NO_DES
377 ctx
= EVP_CIPHER_CTX_new();
381 ret
= cipher_init(ctx
, cipher
, engine
, key
, key_len
);
385 /* Initialize input block */
386 blocksize
= EVP_CIPHER_CTX_block_size(ctx
);
388 if (constant_len
> blocksize
) {
389 ERR_raise(ERR_LIB_PROV
, PROV_R_INVALID_CONSTANT_LENGTH
);
394 n_fold(block
, blocksize
, constant
, constant_len
);
396 cipherblock
= block
+ EVP_MAX_BLOCK_LENGTH
;
398 for (osize
= 0; osize
< okey_len
; osize
+= cipherlen
) {
401 ret
= EVP_EncryptUpdate(ctx
, cipherblock
, &olen
,
402 plainblock
, blocksize
);
406 ret
= EVP_EncryptFinal_ex(ctx
, cipherblock
, &olen
);
410 ERR_raise(ERR_LIB_PROV
, PROV_R_WRONG_FINAL_BLOCK_LENGTH
);
415 /* write cipherblock out */
416 if (cipherlen
> okey_len
- osize
)
417 cipherlen
= okey_len
- osize
;
418 memcpy(okey
+ osize
, cipherblock
, cipherlen
);
420 if (okey_len
> osize
+ cipherlen
) {
421 /* we need to reinitialize cipher context per spec */
422 ret
= EVP_CIPHER_CTX_reset(ctx
);
425 ret
= cipher_init(ctx
, cipher
, engine
, key
, key_len
);
429 /* also swap block offsets so last ciphertext becomes new
431 plainblock
= cipherblock
;
432 if (cipherblock
== block
) {
433 cipherblock
+= EVP_MAX_BLOCK_LENGTH
;
440 #ifndef OPENSSL_NO_DES
441 if (EVP_CIPHER_nid(cipher
) == NID_des_ede3_cbc
&& !des3_no_fixup
) {
442 ret
= fixup_des3_key(okey
);
444 ERR_raise(ERR_LIB_PROV
, PROV_R_FAILED_TO_GENERATE_KEY
);
453 EVP_CIPHER_CTX_free(ctx
);
454 OPENSSL_cleanse(block
, EVP_MAX_BLOCK_LENGTH
* 2);