| /* |
| * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| /* |
| * DES low level APIs are deprecated for public use, but still ok for internal |
| * use. We access the DES_set_odd_parity(3) function here. |
| */ |
| #include "internal/deprecated.h" |
| |
| #include <stdlib.h> |
| #include <stdarg.h> |
| #include <string.h> |
| |
| #include <openssl/core_names.h> |
| #include <openssl/des.h> |
| #include <openssl/evp.h> |
| #include <openssl/kdf.h> |
| #include <openssl/proverr.h> |
| |
| #include "internal/cryptlib.h" |
| #include "crypto/evp.h" |
| #include "internal/numbers.h" |
| #include "prov/implementations.h" |
| #include "prov/provider_ctx.h" |
| #include "prov/provider_util.h" |
| #include "prov/providercommon.h" |
| |
| /* KRB5 KDF defined in RFC 3961, Section 5.1 */ |
| |
| static OSSL_FUNC_kdf_newctx_fn krb5kdf_new; |
| static OSSL_FUNC_kdf_dupctx_fn krb5kdf_dup; |
| static OSSL_FUNC_kdf_freectx_fn krb5kdf_free; |
| static OSSL_FUNC_kdf_reset_fn krb5kdf_reset; |
| static OSSL_FUNC_kdf_derive_fn krb5kdf_derive; |
| static OSSL_FUNC_kdf_settable_ctx_params_fn krb5kdf_settable_ctx_params; |
| static OSSL_FUNC_kdf_set_ctx_params_fn krb5kdf_set_ctx_params; |
| static OSSL_FUNC_kdf_gettable_ctx_params_fn krb5kdf_gettable_ctx_params; |
| static OSSL_FUNC_kdf_get_ctx_params_fn krb5kdf_get_ctx_params; |
| |
| static int KRB5KDF(const EVP_CIPHER *cipher, ENGINE *engine, |
| const unsigned char *key, size_t key_len, |
| const unsigned char *constant, size_t constant_len, |
| unsigned char *okey, size_t okey_len); |
| |
| typedef struct { |
| void *provctx; |
| PROV_CIPHER cipher; |
| unsigned char *key; |
| size_t key_len; |
| unsigned char *constant; |
| size_t constant_len; |
| } KRB5KDF_CTX; |
| |
| static void *krb5kdf_new(void *provctx) |
| { |
| KRB5KDF_CTX *ctx; |
| |
| if (!ossl_prov_is_running()) |
| return NULL; |
| |
| if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) { |
| ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); |
| return NULL; |
| } |
| ctx->provctx = provctx; |
| return ctx; |
| } |
| |
| static void krb5kdf_free(void *vctx) |
| { |
| KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx; |
| |
| if (ctx != NULL) { |
| krb5kdf_reset(ctx); |
| OPENSSL_free(ctx); |
| } |
| } |
| |
| static void krb5kdf_reset(void *vctx) |
| { |
| KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx; |
| void *provctx = ctx->provctx; |
| |
| ossl_prov_cipher_reset(&ctx->cipher); |
| OPENSSL_clear_free(ctx->key, ctx->key_len); |
| OPENSSL_clear_free(ctx->constant, ctx->constant_len); |
| memset(ctx, 0, sizeof(*ctx)); |
| ctx->provctx = provctx; |
| } |
| |
| static int krb5kdf_set_membuf(unsigned char **dst, size_t *dst_len, |
| const OSSL_PARAM *p) |
| { |
| OPENSSL_clear_free(*dst, *dst_len); |
| *dst = NULL; |
| *dst_len = 0; |
| return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len); |
| } |
| |
| static void *krb5kdf_dup(void *vctx) |
| { |
| const KRB5KDF_CTX *src = (const KRB5KDF_CTX *)vctx; |
| KRB5KDF_CTX *dest; |
| |
| dest = krb5kdf_new(src->provctx); |
| if (dest != NULL) { |
| if (!ossl_prov_memdup(src->key, src->key_len, |
| &dest->key, &dest->key_len) |
| || !ossl_prov_memdup(src->constant, src->constant_len, |
| &dest->constant , &dest->constant_len) |
| || !ossl_prov_cipher_copy(&dest->cipher, &src->cipher)) |
| goto err; |
| } |
| return dest; |
| |
| err: |
| krb5kdf_free(dest); |
| return NULL; |
| } |
| |
| static int krb5kdf_derive(void *vctx, unsigned char *key, size_t keylen, |
| const OSSL_PARAM params[]) |
| { |
| KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx; |
| const EVP_CIPHER *cipher; |
| ENGINE *engine; |
| |
| if (!ossl_prov_is_running() || !krb5kdf_set_ctx_params(ctx, params)) |
| return 0; |
| |
| cipher = ossl_prov_cipher_cipher(&ctx->cipher); |
| if (cipher == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CIPHER); |
| return 0; |
| } |
| if (ctx->key == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY); |
| return 0; |
| } |
| if (ctx->constant == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CONSTANT); |
| return 0; |
| } |
| engine = ossl_prov_cipher_engine(&ctx->cipher); |
| return KRB5KDF(cipher, engine, ctx->key, ctx->key_len, |
| ctx->constant, ctx->constant_len, |
| key, keylen); |
| } |
| |
| static int krb5kdf_set_ctx_params(void *vctx, const OSSL_PARAM params[]) |
| { |
| const OSSL_PARAM *p; |
| KRB5KDF_CTX *ctx = vctx; |
| OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx); |
| |
| if (params == NULL) |
| return 1; |
| |
| if (!ossl_prov_cipher_load_from_params(&ctx->cipher, params, provctx)) |
| return 0; |
| |
| if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) |
| if (!krb5kdf_set_membuf(&ctx->key, &ctx->key_len, p)) |
| return 0; |
| |
| if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CONSTANT)) |
| != NULL) |
| if (!krb5kdf_set_membuf(&ctx->constant, &ctx->constant_len, p)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static const OSSL_PARAM *krb5kdf_settable_ctx_params(ossl_unused void *ctx, |
| ossl_unused void *provctx) |
| { |
| static const OSSL_PARAM known_settable_ctx_params[] = { |
| OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0), |
| OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0), |
| OSSL_PARAM_octet_string(OSSL_KDF_PARAM_CONSTANT, NULL, 0), |
| OSSL_PARAM_END |
| }; |
| return known_settable_ctx_params; |
| } |
| |
| static int krb5kdf_get_ctx_params(void *vctx, OSSL_PARAM params[]) |
| { |
| KRB5KDF_CTX *ctx = (KRB5KDF_CTX *)vctx; |
| const EVP_CIPHER *cipher; |
| size_t len; |
| OSSL_PARAM *p; |
| |
| cipher = ossl_prov_cipher_cipher(&ctx->cipher); |
| if (cipher) |
| len = EVP_CIPHER_get_key_length(cipher); |
| else |
| len = EVP_MAX_KEY_LENGTH; |
| |
| if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) |
| return OSSL_PARAM_set_size_t(p, len); |
| return -2; |
| } |
| |
| static const OSSL_PARAM *krb5kdf_gettable_ctx_params(ossl_unused void *ctx, |
| ossl_unused void *provctx) |
| { |
| static const OSSL_PARAM known_gettable_ctx_params[] = { |
| OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), |
| OSSL_PARAM_END |
| }; |
| return known_gettable_ctx_params; |
| } |
| |
| const OSSL_DISPATCH ossl_kdf_krb5kdf_functions[] = { |
| { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))krb5kdf_new }, |
| { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))krb5kdf_dup }, |
| { OSSL_FUNC_KDF_FREECTX, (void(*)(void))krb5kdf_free }, |
| { OSSL_FUNC_KDF_RESET, (void(*)(void))krb5kdf_reset }, |
| { OSSL_FUNC_KDF_DERIVE, (void(*)(void))krb5kdf_derive }, |
| { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS, |
| (void(*)(void))krb5kdf_settable_ctx_params }, |
| { OSSL_FUNC_KDF_SET_CTX_PARAMS, |
| (void(*)(void))krb5kdf_set_ctx_params }, |
| { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS, |
| (void(*)(void))krb5kdf_gettable_ctx_params }, |
| { OSSL_FUNC_KDF_GET_CTX_PARAMS, |
| (void(*)(void))krb5kdf_get_ctx_params }, |
| { 0, NULL } |
| }; |
| |
| #ifndef OPENSSL_NO_DES |
| /* |
| * DES3 is a special case, it requires a random-to-key function and its |
| * input truncated to 21 bytes of the 24 produced by the cipher. |
| * See RFC3961 6.3.1 |
| */ |
| static int fixup_des3_key(unsigned char *key) |
| { |
| unsigned char *cblock; |
| int i, j; |
| |
| for (i = 2; i >= 0; i--) { |
| cblock = &key[i * 8]; |
| memmove(cblock, &key[i * 7], 7); |
| cblock[7] = 0; |
| for (j = 0; j < 7; j++) |
| cblock[7] |= (cblock[j] & 1) << (j + 1); |
| DES_set_odd_parity((DES_cblock *)cblock); |
| } |
| |
| /* fail if keys are such that triple des degrades to single des */ |
| if (CRYPTO_memcmp(&key[0], &key[8], 8) == 0 || |
| CRYPTO_memcmp(&key[8], &key[16], 8) == 0) { |
| return 0; |
| } |
| |
| return 1; |
| } |
| #endif |
| |
| /* |
| * N-fold(K) where blocksize is N, and constant_len is K |
| * Note: Here |= denotes concatenation |
| * |
| * L = lcm(N,K) |
| * R = L/K |
| * |
| * for r: 1 -> R |
| * s |= constant rot 13*(r-1)) |
| * |
| * block = 0 |
| * for k: 1 -> K |
| * block += s[N(k-1)..(N-1)k] (one's complement addition) |
| * |
| * Optimizing for space we compute: |
| * for each l in L-1 -> 0: |
| * s[l] = (constant rot 13*(l/K))[l%k] |
| * block[l % N] += s[l] (with carry) |
| * finally add carry if any |
| */ |
| static void n_fold(unsigned char *block, unsigned int blocksize, |
| const unsigned char *constant, size_t constant_len) |
| { |
| unsigned int tmp, gcd, remainder, lcm, carry; |
| int b, l; |
| |
| if (constant_len == blocksize) { |
| memcpy(block, constant, constant_len); |
| return; |
| } |
| |
| /* Least Common Multiple of lengths: LCM(a,b)*/ |
| gcd = blocksize; |
| remainder = constant_len; |
| /* Calculate Great Common Divisor first GCD(a,b) */ |
| while (remainder != 0) { |
| tmp = gcd % remainder; |
| gcd = remainder; |
| remainder = tmp; |
| } |
| /* resulting a is the GCD, LCM(a,b) = |a*b|/GCD(a,b) */ |
| lcm = blocksize * constant_len / gcd; |
| |
| /* now spread out the bits */ |
| memset(block, 0, blocksize); |
| |
| /* last to first to be able to bring carry forward */ |
| carry = 0; |
| for (l = lcm - 1; l >= 0; l--) { |
| unsigned int rotbits, rshift, rbyte; |
| |
| /* destination byte in block is l % N */ |
| b = l % blocksize; |
| /* Our virtual s buffer is R = L/K long (K = constant_len) */ |
| /* So we rotate backwards from R-1 to 0 (none) rotations */ |
| rotbits = 13 * (l / constant_len); |
| /* find the byte on s where rotbits falls onto */ |
| rbyte = l - (rotbits / 8); |
| /* calculate how much shift on that byte */ |
| rshift = rotbits & 0x07; |
| /* rbyte % constant_len gives us the unrotated byte in the |
| * constant buffer, get also the previous byte then |
| * appropriately shift them to get the rotated byte we need */ |
| tmp = (constant[(rbyte-1) % constant_len] << (8 - rshift) |
| | constant[rbyte % constant_len] >> rshift) |
| & 0xff; |
| /* add with carry to any value placed by previous passes */ |
| tmp += carry + block[b]; |
| block[b] = tmp & 0xff; |
| /* save any carry that may be left */ |
| carry = tmp >> 8; |
| } |
| |
| /* if any carry is left at the end, add it through the number */ |
| for (b = blocksize - 1; b >= 0 && carry != 0; b--) { |
| carry += block[b]; |
| block[b] = carry & 0xff; |
| carry >>= 8; |
| } |
| } |
| |
| static int cipher_init(EVP_CIPHER_CTX *ctx, |
| const EVP_CIPHER *cipher, ENGINE *engine, |
| const unsigned char *key, size_t key_len) |
| { |
| int klen, ret; |
| |
| ret = EVP_EncryptInit_ex(ctx, cipher, engine, key, NULL); |
| if (!ret) |
| goto out; |
| /* set the key len for the odd variable key len cipher */ |
| klen = EVP_CIPHER_CTX_get_key_length(ctx); |
| if (key_len != (size_t)klen) { |
| ret = EVP_CIPHER_CTX_set_key_length(ctx, key_len); |
| if (!ret) |
| goto out; |
| } |
| /* we never want padding, either the length requested is a multiple of |
| * the cipher block size or we are passed a cipher that can cope with |
| * partial blocks via techniques like cipher text stealing */ |
| ret = EVP_CIPHER_CTX_set_padding(ctx, 0); |
| if (!ret) |
| goto out; |
| |
| out: |
| return ret; |
| } |
| |
| static int KRB5KDF(const EVP_CIPHER *cipher, ENGINE *engine, |
| const unsigned char *key, size_t key_len, |
| const unsigned char *constant, size_t constant_len, |
| unsigned char *okey, size_t okey_len) |
| { |
| EVP_CIPHER_CTX *ctx = NULL; |
| unsigned char block[EVP_MAX_BLOCK_LENGTH * 2]; |
| unsigned char *plainblock, *cipherblock; |
| size_t blocksize; |
| size_t cipherlen; |
| size_t osize; |
| #ifndef OPENSSL_NO_DES |
| int des3_no_fixup = 0; |
| #endif |
| int ret; |
| |
| if (key_len != okey_len) { |
| #ifndef OPENSSL_NO_DES |
| /* special case for 3des, where the caller may be requesting |
| * the random raw key, instead of the fixed up key */ |
| if (EVP_CIPHER_get_nid(cipher) == NID_des_ede3_cbc && |
| key_len == 24 && okey_len == 21) { |
| des3_no_fixup = 1; |
| } else { |
| #endif |
| ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_OUTPUT_BUFFER_SIZE); |
| return 0; |
| #ifndef OPENSSL_NO_DES |
| } |
| #endif |
| } |
| |
| ctx = EVP_CIPHER_CTX_new(); |
| if (ctx == NULL) |
| return 0; |
| |
| ret = cipher_init(ctx, cipher, engine, key, key_len); |
| if (!ret) |
| goto out; |
| |
| /* Initialize input block */ |
| blocksize = EVP_CIPHER_CTX_get_block_size(ctx); |
| |
| if (constant_len > blocksize) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CONSTANT_LENGTH); |
| ret = 0; |
| goto out; |
| } |
| |
| n_fold(block, blocksize, constant, constant_len); |
| plainblock = block; |
| cipherblock = block + EVP_MAX_BLOCK_LENGTH; |
| |
| for (osize = 0; osize < okey_len; osize += cipherlen) { |
| int olen; |
| |
| ret = EVP_EncryptUpdate(ctx, cipherblock, &olen, |
| plainblock, blocksize); |
| if (!ret) |
| goto out; |
| cipherlen = olen; |
| ret = EVP_EncryptFinal_ex(ctx, cipherblock, &olen); |
| if (!ret) |
| goto out; |
| if (olen != 0) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_WRONG_FINAL_BLOCK_LENGTH); |
| ret = 0; |
| goto out; |
| } |
| |
| /* write cipherblock out */ |
| if (cipherlen > okey_len - osize) |
| cipherlen = okey_len - osize; |
| memcpy(okey + osize, cipherblock, cipherlen); |
| |
| if (okey_len > osize + cipherlen) { |
| /* we need to reinitialize cipher context per spec */ |
| ret = EVP_CIPHER_CTX_reset(ctx); |
| if (!ret) |
| goto out; |
| ret = cipher_init(ctx, cipher, engine, key, key_len); |
| if (!ret) |
| goto out; |
| |
| /* also swap block offsets so last ciphertext becomes new |
| * plaintext */ |
| plainblock = cipherblock; |
| if (cipherblock == block) { |
| cipherblock += EVP_MAX_BLOCK_LENGTH; |
| } else { |
| cipherblock = block; |
| } |
| } |
| } |
| |
| #ifndef OPENSSL_NO_DES |
| if (EVP_CIPHER_get_nid(cipher) == NID_des_ede3_cbc && !des3_no_fixup) { |
| ret = fixup_des3_key(okey); |
| if (!ret) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GENERATE_KEY); |
| goto out; |
| } |
| } |
| #endif |
| |
| ret = 1; |
| |
| out: |
| EVP_CIPHER_CTX_free(ctx); |
| OPENSSL_cleanse(block, EVP_MAX_BLOCK_LENGTH * 2); |
| return ret; |
| } |
| |
