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);
70 ctx->provctx = provctx;
74 static void krb5kdf_free(void *vctx)
76 KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx;
84 static void krb5kdf_reset(void *vctx)
86 KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx;
87 void *provctx = ctx->provctx;
89 ossl_prov_cipher_reset(&ctx->cipher);
90 OPENSSL_clear_free(ctx->key, ctx->key_len);
91 OPENSSL_clear_free(ctx->constant, ctx->constant_len);
92 memset(ctx, 0, sizeof(*ctx));
93 ctx->provctx = provctx;
96 static int krb5kdf_set_membuf(unsigned char **dst, size_t *dst_len,
99 OPENSSL_clear_free(*dst, *dst_len);
101 return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
104 static int krb5kdf_derive(void *vctx, unsigned char *key,
107 KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx;
108 const EVP_CIPHER *cipher;
111 if (!ossl_prov_is_running())
114 cipher = ossl_prov_cipher_cipher(&ctx->cipher);
115 if (cipher == NULL) {
116 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CIPHER);
119 if (ctx->key == NULL) {
120 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
123 if (ctx->constant == NULL) {
124 ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CONSTANT);
127 engine = ossl_prov_cipher_engine(&ctx->cipher);
128 return KRB5KDF(cipher, engine, ctx->key, ctx->key_len,
129 ctx->constant, ctx->constant_len,
133 static int krb5kdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
136 KRB5KDF_CTX *ctx = vctx;
137 OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
139 if (!ossl_prov_cipher_load_from_params(&ctx->cipher, params, provctx))
142 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
143 if (!krb5kdf_set_membuf(&ctx->key, &ctx->key_len, p))
146 if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CONSTANT))
148 if (!krb5kdf_set_membuf(&ctx->constant, &ctx->constant_len, p))
154 static const OSSL_PARAM *krb5kdf_settable_ctx_params(ossl_unused void *provctx)
156 static const OSSL_PARAM known_settable_ctx_params[] = {
157 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
158 OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
159 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
160 OSSL_PARAM_octet_string(OSSL_KDF_PARAM_CONSTANT, NULL, 0),
163 return known_settable_ctx_params;
166 static int krb5kdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
168 KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx;
169 const EVP_CIPHER *cipher;
173 cipher = ossl_prov_cipher_cipher(&ctx->cipher);
175 len = EVP_CIPHER_key_length(cipher);
177 len = EVP_MAX_KEY_LENGTH;
179 if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
180 return OSSL_PARAM_set_size_t(p, len);
184 static const OSSL_PARAM *krb5kdf_gettable_ctx_params(ossl_unused void *provctx)
186 static const OSSL_PARAM known_gettable_ctx_params[] = {
187 OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
190 return known_gettable_ctx_params;
193 const OSSL_DISPATCH ossl_kdf_krb5kdf_functions[] = {
194 { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))krb5kdf_new },
195 { OSSL_FUNC_KDF_FREECTX, (void(*)(void))krb5kdf_free },
196 { OSSL_FUNC_KDF_RESET, (void(*)(void))krb5kdf_reset },
197 { OSSL_FUNC_KDF_DERIVE, (void(*)(void))krb5kdf_derive },
198 { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
199 (void(*)(void))krb5kdf_settable_ctx_params },
200 { OSSL_FUNC_KDF_SET_CTX_PARAMS,
201 (void(*)(void))krb5kdf_set_ctx_params },
202 { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
203 (void(*)(void))krb5kdf_gettable_ctx_params },
204 { OSSL_FUNC_KDF_GET_CTX_PARAMS,
205 (void(*)(void))krb5kdf_get_ctx_params },
209 #ifndef OPENSSL_NO_DES
211 * DES3 is a special case, it requires a random-to-key function and its
212 * input truncated to 21 bytes of the 24 produced by the cipher.
215 static int fixup_des3_key(unsigned char *key)
217 unsigned char *cblock;
220 for (i = 2; i >= 0; i--) {
221 cblock = &key[i * 8];
222 memmove(cblock, &key[i * 7], 7);
224 for (j = 0; j < 7; j++)
225 cblock[7] |= (cblock[j] & 1) << (j + 1);
226 DES_set_odd_parity((DES_cblock *)cblock);
229 /* fail if keys are such that triple des degrades to single des */
230 if (CRYPTO_memcmp(&key[0], &key[8], 8) == 0 ||
231 CRYPTO_memcmp(&key[8], &key[16], 8) == 0) {
240 * N-fold(K) where blocksize is N, and constant_len is K
241 * Note: Here |= denotes concatenation
247 * s |= constant rot 13*(r-1))
251 * block += s[N(k-1)..(N-1)k] (one's complement addition)
253 * Optimizing for space we compute:
254 * for each l in L-1 -> 0:
255 * s[l] = (constant rot 13*(l/K))[l%k]
256 * block[l % N] += s[l] (with carry)
257 * finally add carry if any
259 static void n_fold(unsigned char *block, unsigned int blocksize,
260 const unsigned char *constant, size_t constant_len)
262 unsigned int tmp, gcd, remainder, lcm, carry;
265 if (constant_len == blocksize) {
266 memcpy(block, constant, constant_len);
270 /* Least Common Multiple of lengths: LCM(a,b)*/
272 remainder = constant_len;
273 /* Calculate Great Common Divisor first GCD(a,b) */
274 while (remainder != 0) {
275 tmp = gcd % remainder;
279 /* resulting a is the GCD, LCM(a,b) = |a*b|/GCD(a,b) */
280 lcm = blocksize * constant_len / gcd;
282 /* now spread out the bits */
283 memset(block, 0, blocksize);
285 /* last to first to be able to bring carry forward */
287 for (l = lcm - 1; l >= 0; l--) {
288 unsigned int rotbits, rshift, rbyte;
290 /* destination byte in block is l % N */
292 /* Our virtual s buffer is R = L/K long (K = constant_len) */
293 /* So we rotate backwards from R-1 to 0 (none) rotations */
294 rotbits = 13 * (l / constant_len);
295 /* find the byte on s where rotbits falls onto */
296 rbyte = l - (rotbits / 8);
297 /* calculate how much shift on that byte */
298 rshift = rotbits & 0x07;
299 /* rbyte % constant_len gives us the unrotated byte in the
300 * constant buffer, get also the previous byte then
301 * appropriately shift them to get the rotated byte we need */
302 tmp = (constant[(rbyte-1) % constant_len] << (8 - rshift)
303 | constant[rbyte % constant_len] >> rshift)
305 /* add with carry to any value placed by previous passes */
306 tmp += carry + block[b];
307 block[b] = tmp & 0xff;
308 /* save any carry that may be left */
312 /* if any carry is left at the end, add it through the number */
313 for (b = blocksize - 1; b >= 0 && carry != 0; b--) {
315 block[b] = carry & 0xff;
320 static int cipher_init(EVP_CIPHER_CTX *ctx,
321 const EVP_CIPHER *cipher, ENGINE *engine,
322 const unsigned char *key, size_t key_len)
326 ret = EVP_EncryptInit_ex(ctx, cipher, engine, key, NULL);
329 /* set the key len for the odd variable key len cipher */
330 klen = EVP_CIPHER_CTX_key_length(ctx);
331 if (key_len != (size_t)klen) {
332 ret = EVP_CIPHER_CTX_set_key_length(ctx, key_len);
336 /* we never want padding, either the length requested is a multiple of
337 * the cipher block size or we are passed a cipher that can cope with
338 * partial blocks via techniques like cipher text stealing */
339 ret = EVP_CIPHER_CTX_set_padding(ctx, 0);
347 static int KRB5KDF(const EVP_CIPHER *cipher, ENGINE *engine,
348 const unsigned char *key, size_t key_len,
349 const unsigned char *constant, size_t constant_len,
350 unsigned char *okey, size_t okey_len)
352 EVP_CIPHER_CTX *ctx = NULL;
353 unsigned char block[EVP_MAX_BLOCK_LENGTH * 2];
354 unsigned char *plainblock, *cipherblock;
358 #ifndef OPENSSL_NO_DES
359 int des3_no_fixup = 0;
363 if (key_len != okey_len) {
364 #ifndef OPENSSL_NO_DES
365 /* special case for 3des, where the caller may be requesting
366 * the random raw key, instead of the fixed up key */
367 if (EVP_CIPHER_nid(cipher) == NID_des_ede3_cbc &&
368 key_len == 24 && okey_len == 21) {
372 ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_OUTPUT_BUFFER_SIZE);
374 #ifndef OPENSSL_NO_DES
379 ctx = EVP_CIPHER_CTX_new();
383 ret = cipher_init(ctx, cipher, engine, key, key_len);
387 /* Initialize input block */
388 blocksize = EVP_CIPHER_CTX_block_size(ctx);
390 if (constant_len > blocksize) {
391 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CONSTANT_LENGTH);
396 n_fold(block, blocksize, constant, constant_len);
398 cipherblock = block + EVP_MAX_BLOCK_LENGTH;
400 for (osize = 0; osize < okey_len; osize += cipherlen) {
403 ret = EVP_EncryptUpdate(ctx, cipherblock, &olen,
404 plainblock, blocksize);
408 ret = EVP_EncryptFinal_ex(ctx, cipherblock, &olen);
412 ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_FINAL_BLOCK_LENGTH);
417 /* write cipherblock out */
418 if (cipherlen > okey_len - osize)
419 cipherlen = okey_len - osize;
420 memcpy(okey + osize, cipherblock, cipherlen);
422 if (okey_len > osize + cipherlen) {
423 /* we need to reinitialize cipher context per spec */
424 ret = EVP_CIPHER_CTX_reset(ctx);
427 ret = cipher_init(ctx, cipher, engine, key, key_len);
431 /* also swap block offsets so last ciphertext becomes new
433 plainblock = cipherblock;
434 if (cipherblock == block) {
435 cipherblock += EVP_MAX_BLOCK_LENGTH;
442 #ifndef OPENSSL_NO_DES
443 if (EVP_CIPHER_nid(cipher) == NID_des_ede3_cbc && !des3_no_fixup) {
444 ret = fixup_des3_key(okey);
446 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GENERATE_KEY);
455 EVP_CIPHER_CTX_free(ctx);
456 OPENSSL_cleanse(block, EVP_MAX_BLOCK_LENGTH * 2);