diff --git a/library/CMakeLists.txt b/library/CMakeLists.txt index 4aba062bc..70fff520a 100644 --- a/library/CMakeLists.txt +++ b/library/CMakeLists.txt @@ -40,6 +40,7 @@ set(src_crypto md5.c md_wrap.c memory_buffer_alloc.c + nist_kw.c oid.c padlock.c pem.c diff --git a/library/Makefile b/library/Makefile index b1597e0e5..ac88d4c3f 100644 --- a/library/Makefile +++ b/library/Makefile @@ -76,11 +76,11 @@ OBJS_CRYPTO= aes.o aesni.o arc4.o \ hkdf.o \ hmac_drbg.o md.o md2.o \ md4.o md5.o md_wrap.o \ - memory_buffer_alloc.o oid.o \ - padlock.o pem.o pk.o \ - pk_wrap.o pkcs12.o pkcs5.o \ - pkparse.o pkwrite.o platform.o \ - platform_util.o poly1305.o \ + memory_buffer_alloc.o nist_kw.o \ + oid.o padlock.o pem.o \ + pk.o pk_wrap.o pkcs12.o \ + pkcs5.o pkparse.o pkwrite.o \ + platform.o platform_util.o poly1305.o \ ripemd160.o rsa_internal.o rsa.o \ sha1.o sha256.o sha512.o \ threading.o timing.o version.o \ diff --git a/library/nist_kw.c b/library/nist_kw.c new file mode 100644 index 000000000..b7790d73c --- /dev/null +++ b/library/nist_kw.c @@ -0,0 +1,537 @@ +/* + * Implementation of NIST SP 800-38F key wrapping, supporting KW and KWP modes + * only + * + * Copyright (C) 2018, Arm Limited (or its affiliates), All Rights Reserved + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * This file is part of Mbed TLS (https://tls.mbed.org) + */ +/* + * Definition of Key Wrapping: + * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf + * RFC 3394 "Advanced Encryption Standard (AES) Key Wrap Algorithm" + * RFC 5649 "Advanced Encryption Standard (AES) Key Wrap with Padding Algorithm" + * + * Note: RFC 3394 defines different methodology for intermediate operations for + * the wrapping and unwrapping operation than the definition in NIST SP 800-38F. + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#if defined(MBEDTLS_NIST_KW_C) + +#include "mbedtls/nist_kw.h" +#include "mbedtls/platform_util.h" + +#include +#include + +#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) +#if defined(MBEDTLS_PLATFORM_C) +#include "mbedtls/platform.h" +#else +#include +#define mbedtls_printf printf +#endif /* MBEDTLS_PLATFORM_C */ +#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ + +#if !defined(MBEDTLS_NIST_KW_ALT) + +#define KW_SEMIBLOCK_LENGTH 8 +#define MIN_SEMIBLOCKS_COUNT 3 + +/* constant-time buffer comparison */ +static inline unsigned char mbedtls_nist_kw_safer_memcmp( const void *a, const void *b, size_t n ) +{ + size_t i; + volatile const unsigned char *A = (volatile const unsigned char *) a; + volatile const unsigned char *B = (volatile const unsigned char *) b; + volatile unsigned char diff = 0; + + for( i = 0; i < n; i++ ) + { + /* Read volatile data in order before computing diff. + * This avoids IAR compiler warning: + * 'the order of volatile accesses is undefined ..' */ + unsigned char x = A[i], y = B[i]; + diff |= x ^ y; + } + + return( diff ); +} + +/*! The 64-bit default integrity check value (ICV) for KW mode. */ +static const unsigned char NIST_KW_ICV1[] = {0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6}; +/*! The 32-bit default integrity check value (ICV) for KWP mode. */ +static const unsigned char NIST_KW_ICV2[] = {0xA6, 0x59, 0x59, 0xA6}; + +#ifndef GET_UINT32_BE +#define GET_UINT32_BE(n,b,i) \ +do { \ + (n) = ( (uint32_t) (b)[(i) ] << 24 ) \ + | ( (uint32_t) (b)[(i) + 1] << 16 ) \ + | ( (uint32_t) (b)[(i) + 2] << 8 ) \ + | ( (uint32_t) (b)[(i) + 3] ); \ +} while( 0 ) +#endif + +#ifndef PUT_UINT32_BE +#define PUT_UINT32_BE(n,b,i) \ +do { \ + (b)[(i) ] = (unsigned char) ( (n) >> 24 ); \ + (b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \ + (b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \ + (b)[(i) + 3] = (unsigned char) ( (n) ); \ +} while( 0 ) +#endif + +/* + * Initialize context + */ +void mbedtls_nist_kw_init( mbedtls_nist_kw_context *ctx ) +{ + memset( ctx, 0, sizeof( mbedtls_nist_kw_context ) ); +} + +int mbedtls_nist_kw_setkey( mbedtls_nist_kw_context *ctx, + mbedtls_cipher_id_t cipher, + const unsigned char *key, + unsigned int keybits, + const int is_wrap ) +{ + int ret; + const mbedtls_cipher_info_t *cipher_info; + + cipher_info = mbedtls_cipher_info_from_values( cipher, + keybits, + MBEDTLS_MODE_ECB ); + if( cipher_info == NULL ) + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + + if( cipher_info->block_size != 16 ) + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + + /* + * SP 800-38F currently defines AES cipher as the only block cipher allowed: + * "For KW and KWP, the underlying block cipher shall be approved, and the + * block size shall be 128 bits. Currently, the AES block cipher, with key + * lengths of 128, 192, or 256 bits, is the only block cipher that fits + * this profile." + * Currently we don't support other 128 bit block ciphers for key wrapping, + * such as Camellia and Aria. + */ + if( cipher != MBEDTLS_CIPHER_ID_AES ) + return( MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE ); + + mbedtls_cipher_free( &ctx->cipher_ctx ); + + if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 ) + return( ret ); + + if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits, + is_wrap ? MBEDTLS_ENCRYPT : + MBEDTLS_DECRYPT ) + ) != 0 ) + { + return( ret ); + } + + return( 0 ); +} + +/* + * Free context + */ +void mbedtls_nist_kw_free( mbedtls_nist_kw_context *ctx ) +{ + mbedtls_cipher_free( &ctx->cipher_ctx ); + mbedtls_platform_zeroize( ctx, sizeof( mbedtls_nist_kw_context ) ); +} + +/* + * Helper function for Xoring the uint64_t "t" with the encrypted A. + * Defined in NIST SP 800-38F section 6.1 + */ +static void calc_a_xor_t( unsigned char A[KW_SEMIBLOCK_LENGTH], uint64_t t ) +{ + size_t i = 0; + for( i = 0; i < sizeof( t ); i++ ) + { + A[i] ^= ( t >> ( ( sizeof( t ) - 1 - i ) * 8 ) ) & 0xff; + } +} + +/* + * KW-AE as defined in SP 800-38F section 6.2 + * KWP-AE as defined in SP 800-38F section 6.3 + */ +int mbedtls_nist_kw_wrap( mbedtls_nist_kw_context *ctx, + mbedtls_nist_kw_mode_t mode, + const unsigned char *input, size_t in_len, + unsigned char *output, size_t *out_len, size_t out_size ) +{ + int ret = 0; + size_t semiblocks = 0; + size_t s; + size_t olen, padlen = 0; + uint64_t t = 0; + unsigned char outbuff[KW_SEMIBLOCK_LENGTH * 2]; + unsigned char inbuff[KW_SEMIBLOCK_LENGTH * 2]; + unsigned char *R2 = output + KW_SEMIBLOCK_LENGTH; + unsigned char *A = output; + + *out_len = 0; + /* + * Generate the String to work on + */ + if( mode == MBEDTLS_KW_MODE_KW ) + { + if( out_size < in_len + KW_SEMIBLOCK_LENGTH ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + /* + * According to SP 800-38F Table 1, the plaintext length for KW + * must be between 2 to 2^54-1 semiblocks inclusive. + */ + if( in_len < 16 || +#if SIZE_MAX > 0x1FFFFFFFFFFFFF8 + in_len > 0x1FFFFFFFFFFFFF8 || +#endif + in_len % KW_SEMIBLOCK_LENGTH != 0 ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + memcpy( output, NIST_KW_ICV1, KW_SEMIBLOCK_LENGTH ); + memmove( output + KW_SEMIBLOCK_LENGTH, input, in_len ); + } + else + { + if( in_len % 8 != 0 ) + { + padlen = ( 8 - ( in_len % 8 ) ); + } + + if( out_size < in_len + KW_SEMIBLOCK_LENGTH + padlen ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + /* + * According to SP 800-38F Table 1, the plaintext length for KWP + * must be between 1 and 2^32-1 octets inclusive. + */ + if( in_len < 1 +#if SIZE_MAX > 0xFFFFFFFF + || in_len > 0xFFFFFFFF +#endif + ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + memcpy( output, NIST_KW_ICV2, KW_SEMIBLOCK_LENGTH / 2 ); + PUT_UINT32_BE( ( in_len & 0xffffffff ), output, + KW_SEMIBLOCK_LENGTH / 2 ); + + memcpy( output + KW_SEMIBLOCK_LENGTH, input, in_len ); + memset( output + KW_SEMIBLOCK_LENGTH + in_len, 0, padlen ); + } + semiblocks = ( ( in_len + padlen ) / KW_SEMIBLOCK_LENGTH ) + 1; + + s = 6 * ( semiblocks - 1 ); + + if( mode == MBEDTLS_KW_MODE_KWP + && in_len <= KW_SEMIBLOCK_LENGTH ) + { + memcpy( inbuff, output, 16 ); + ret = mbedtls_cipher_update( &ctx->cipher_ctx, + inbuff, 16, output, &olen ); + if( ret != 0 ) + goto cleanup; + } + else + { + /* + * Do the wrapping function W, as defined in RFC 3394 section 2.2.1 + */ + if( semiblocks < MIN_SEMIBLOCKS_COUNT ) + { + ret = MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA; + goto cleanup; + } + + /* Calculate intermediate values */ + for( t = 1; t <= s; t++ ) + { + memcpy( inbuff, A, KW_SEMIBLOCK_LENGTH ); + memcpy( inbuff + KW_SEMIBLOCK_LENGTH, R2, KW_SEMIBLOCK_LENGTH ); + + ret = mbedtls_cipher_update( &ctx->cipher_ctx, + inbuff, 16, outbuff, &olen ); + if( ret != 0 ) + goto cleanup; + + memcpy( A, outbuff, KW_SEMIBLOCK_LENGTH ); + calc_a_xor_t( A, t ); + + memcpy( R2, outbuff + KW_SEMIBLOCK_LENGTH, KW_SEMIBLOCK_LENGTH ); + R2 += KW_SEMIBLOCK_LENGTH; + if( R2 >= output + ( semiblocks * KW_SEMIBLOCK_LENGTH ) ) + R2 = output + KW_SEMIBLOCK_LENGTH; + } + } + + *out_len = semiblocks * KW_SEMIBLOCK_LENGTH; + +cleanup: + + if( ret != 0) + { + memset( output, 0, semiblocks * KW_SEMIBLOCK_LENGTH ); + } + mbedtls_platform_zeroize( inbuff, KW_SEMIBLOCK_LENGTH * 2 ); + mbedtls_platform_zeroize( outbuff, KW_SEMIBLOCK_LENGTH * 2 ); + mbedtls_cipher_finish( &ctx->cipher_ctx, NULL, &olen ); + return( ret ); +} + +/* + * W-1 function as defined in RFC 3394 section 2.2.2 + * This function assumes the following: + * 1. Output buffer is at least of size ( semiblocks - 1 ) * KW_SEMIBLOCK_LENGTH. + * 2. The input buffer is of size semiblocks * KW_SEMIBLOCK_LENGTH. + * 3. Minimal number of semiblocks is 3. + * 4. A is a buffer to hold the first semiblock of the input buffer. + */ +static int unwrap( mbedtls_nist_kw_context *ctx, + const unsigned char *input, size_t semiblocks, + unsigned char A[KW_SEMIBLOCK_LENGTH], + unsigned char *output, size_t* out_len ) +{ + int ret = 0; + const size_t s = 6 * ( semiblocks - 1 ); + size_t olen; + uint64_t t = 0; + unsigned char outbuff[KW_SEMIBLOCK_LENGTH * 2]; + unsigned char inbuff[KW_SEMIBLOCK_LENGTH * 2]; + unsigned char *R = output + ( semiblocks - 2 ) * KW_SEMIBLOCK_LENGTH; + *out_len = 0; + + if( semiblocks < MIN_SEMIBLOCKS_COUNT ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + memcpy( A, input, KW_SEMIBLOCK_LENGTH ); + memmove( output, input + KW_SEMIBLOCK_LENGTH, ( semiblocks - 1 ) * KW_SEMIBLOCK_LENGTH ); + + /* Calculate intermediate values */ + for( t = s; t >= 1; t-- ) + { + calc_a_xor_t( A, t ); + + memcpy( inbuff, A, KW_SEMIBLOCK_LENGTH ); + memcpy( inbuff + KW_SEMIBLOCK_LENGTH, R, KW_SEMIBLOCK_LENGTH ); + + ret = mbedtls_cipher_update( &ctx->cipher_ctx, + inbuff, 16, outbuff, &olen ); + if( ret != 0 ) + goto cleanup; + + memcpy( A, outbuff, KW_SEMIBLOCK_LENGTH ); + + /* Set R as LSB64 of outbuff */ + memcpy( R, outbuff + KW_SEMIBLOCK_LENGTH, KW_SEMIBLOCK_LENGTH ); + + if( R == output ) + R = output + ( semiblocks - 2 ) * KW_SEMIBLOCK_LENGTH; + else + R -= KW_SEMIBLOCK_LENGTH; + } + + *out_len = ( semiblocks - 1 ) * KW_SEMIBLOCK_LENGTH; + +cleanup: + if( ret != 0) + memset( output, 0, ( semiblocks - 1 ) * KW_SEMIBLOCK_LENGTH ); + mbedtls_platform_zeroize( inbuff, sizeof( inbuff ) ); + mbedtls_platform_zeroize( outbuff, sizeof( outbuff ) ); + + return( ret ); +} + +/* + * KW-AD as defined in SP 800-38F section 6.2 + * KWP-AD as defined in SP 800-38F section 6.3 + */ +int mbedtls_nist_kw_unwrap( mbedtls_nist_kw_context *ctx, + mbedtls_nist_kw_mode_t mode, + const unsigned char *input, size_t in_len, + unsigned char *output, size_t *out_len, size_t out_size ) +{ + int ret = 0; + size_t i, olen; + unsigned char A[KW_SEMIBLOCK_LENGTH]; + unsigned char diff, bad_padding = 0; + + *out_len = 0; + if( out_size < in_len - KW_SEMIBLOCK_LENGTH ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + if( mode == MBEDTLS_KW_MODE_KW ) + { + /* + * According to SP 800-38F Table 1, the ciphertext length for KW + * must be between 3 to 2^54 semiblocks inclusive. + */ + if( in_len < 24 || +#if SIZE_MAX > 0x200000000000000 + in_len > 0x200000000000000 || +#endif + in_len % KW_SEMIBLOCK_LENGTH != 0 ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + ret = unwrap( ctx, input, in_len / KW_SEMIBLOCK_LENGTH, + A, output, out_len ); + if( ret != 0 ) + goto cleanup; + + /* Check ICV in "constant-time" */ + diff = mbedtls_nist_kw_safer_memcmp( NIST_KW_ICV1, A, KW_SEMIBLOCK_LENGTH ); + + if( diff != 0 ) + { + ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED; + goto cleanup; + } + + } + else if( mode == MBEDTLS_KW_MODE_KWP ) + { + size_t padlen = 0; + uint32_t Plen; + /* + * According to SP 800-38F Table 1, the ciphertext length for KWP + * must be between 2 to 2^29 semiblocks inclusive. + */ + if( in_len < KW_SEMIBLOCK_LENGTH * 2 || +#if SIZE_MAX > 0x100000000 + in_len > 0x100000000 || +#endif + in_len % KW_SEMIBLOCK_LENGTH != 0 ) + { + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + if( in_len == KW_SEMIBLOCK_LENGTH * 2 ) + { + unsigned char outbuff[KW_SEMIBLOCK_LENGTH * 2]; + ret = mbedtls_cipher_update( &ctx->cipher_ctx, + input, 16, outbuff, &olen ); + if( ret != 0 ) + goto cleanup; + + memcpy( A, outbuff, KW_SEMIBLOCK_LENGTH ); + memcpy( output, outbuff + KW_SEMIBLOCK_LENGTH, KW_SEMIBLOCK_LENGTH ); + mbedtls_platform_zeroize( outbuff, sizeof( outbuff ) ); + *out_len = KW_SEMIBLOCK_LENGTH; + } + else + { + /* in_len >= KW_SEMIBLOCK_LENGTH * 3 */ + ret = unwrap( ctx, input, in_len / KW_SEMIBLOCK_LENGTH, + A, output, out_len ); + if( ret != 0 ) + goto cleanup; + } + + /* Check ICV in "constant-time" */ + diff = mbedtls_nist_kw_safer_memcmp( NIST_KW_ICV2, A, KW_SEMIBLOCK_LENGTH / 2 ); + + if( diff != 0 ) + { + ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED; + } + + GET_UINT32_BE( Plen, A, KW_SEMIBLOCK_LENGTH / 2 ); + + /* + * Plen is the length of the plaintext, when the input is valid. + * If Plen is larger than the plaintext and padding, padlen will be + * larger than 8, because of the type wrap around. + */ + padlen = in_len - KW_SEMIBLOCK_LENGTH - Plen; + if ( padlen > 7 ) + { + padlen &= 7; + ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED; + } + + /* Check padding in "constant-time" */ + for( diff = 0, i = 0; i < KW_SEMIBLOCK_LENGTH; i++ ) + { + if( i >= KW_SEMIBLOCK_LENGTH - padlen ) + diff |= output[*out_len - KW_SEMIBLOCK_LENGTH + i]; + else + bad_padding |= output[*out_len - KW_SEMIBLOCK_LENGTH + i]; + } + + if( diff != 0 ) + { + ret = MBEDTLS_ERR_CIPHER_AUTH_FAILED; + } + + if( ret != 0 ) + { + goto cleanup; + } + memset( output + Plen, 0, padlen ); + *out_len = Plen; + } + else + { + ret = MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE; + goto cleanup; + } + +cleanup: + if( ret != 0 ) + { + memset( output, 0, *out_len ); + *out_len = 0; + } + + mbedtls_platform_zeroize( &bad_padding, sizeof( bad_padding) ); + mbedtls_platform_zeroize( &diff, sizeof( diff ) ); + mbedtls_platform_zeroize( A, sizeof( A ) ); + mbedtls_cipher_finish( &ctx->cipher_ctx, NULL, &olen ); + return( ret ); +} + +#endif /* !MBEDTLS_NIST_KW_ALT */ + +#endif /* MBEDTLS_NIST_KW_C */ diff --git a/visualc/VS2010/mbedTLS.vcxproj b/visualc/VS2010/mbedTLS.vcxproj index e58a2fbc2..73c92bda5 100644 --- a/visualc/VS2010/mbedTLS.vcxproj +++ b/visualc/VS2010/mbedTLS.vcxproj @@ -191,6 +191,7 @@ + @@ -265,6 +266,7 @@ +