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);