730 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			730 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | /*
 | ||
|  |  *  NIST SP800-38C compliant CCM implementation | ||
|  |  * | ||
|  |  *  Copyright The Mbed TLS Contributors | ||
|  |  *  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. | ||
|  |  */ | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Definition of CCM: | ||
|  |  * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
 | ||
|  |  * RFC 3610 "Counter with CBC-MAC (CCM)" | ||
|  |  * | ||
|  |  * Related: | ||
|  |  * RFC 5116 "An Interface and Algorithms for Authenticated Encryption" | ||
|  |  */ | ||
|  | 
 | ||
|  | #include "common.h"
 | ||
|  | 
 | ||
|  | #if defined(MBEDTLS_CCM_C)
 | ||
|  | 
 | ||
|  | #include "mbedtls/ccm.h"
 | ||
|  | #include "mbedtls/platform_util.h"
 | ||
|  | #include "mbedtls/error.h"
 | ||
|  | 
 | ||
|  | #include <string.h>
 | ||
|  | 
 | ||
|  | #if defined(MBEDTLS_PLATFORM_C)
 | ||
|  | #include "mbedtls/platform.h"
 | ||
|  | #else
 | ||
|  | #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
 | ||
|  | #include <stdio.h>
 | ||
|  | #define mbedtls_printf printf
 | ||
|  | #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
 | ||
|  | #endif /* MBEDTLS_PLATFORM_C */
 | ||
|  | 
 | ||
|  | #if !defined(MBEDTLS_CCM_ALT)
 | ||
|  | 
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Initialize context | ||
|  |  */ | ||
|  | void mbedtls_ccm_init(mbedtls_ccm_context *ctx) | ||
|  | { | ||
|  |     memset(ctx, 0, sizeof(mbedtls_ccm_context)); | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx, | ||
|  |                        mbedtls_cipher_id_t cipher, | ||
|  |                        const unsigned char *key, | ||
|  |                        unsigned int keybits) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     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_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (mbedtls_cipher_info_get_block_size(cipher_info) != 16) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     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, | ||
|  |                                      MBEDTLS_ENCRYPT)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Free context | ||
|  |  */ | ||
|  | void mbedtls_ccm_free(mbedtls_ccm_context *ctx) | ||
|  | { | ||
|  |     if (ctx == NULL) { | ||
|  |         return; | ||
|  |     } | ||
|  |     mbedtls_cipher_free(&ctx->cipher_ctx); | ||
|  |     mbedtls_platform_zeroize(ctx, sizeof(mbedtls_ccm_context)); | ||
|  | } | ||
|  | 
 | ||
|  | #define CCM_STATE__CLEAR                0
 | ||
|  | #define CCM_STATE__STARTED              (1 << 0)
 | ||
|  | #define CCM_STATE__LENGTHS_SET          (1 << 1)
 | ||
|  | #define CCM_STATE__AUTH_DATA_STARTED    (1 << 2)
 | ||
|  | #define CCM_STATE__AUTH_DATA_FINISHED   (1 << 3)
 | ||
|  | #define CCM_STATE__ERROR                (1 << 4)
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Encrypt or decrypt a partial block with CTR | ||
|  |  */ | ||
|  | static int mbedtls_ccm_crypt(mbedtls_ccm_context *ctx, | ||
|  |                              size_t offset, size_t use_len, | ||
|  |                              const unsigned char *input, | ||
|  |                              unsigned char *output) | ||
|  | { | ||
|  |     size_t olen = 0; | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     unsigned char tmp_buf[16] = { 0 }; | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->ctr, 16, tmp_buf, | ||
|  |                                      &olen)) != 0) { | ||
|  |         ctx->state |= CCM_STATE__ERROR; | ||
|  |         mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf)); | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     mbedtls_xor(output, input, tmp_buf + offset, use_len); | ||
|  | 
 | ||
|  |     mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf)); | ||
|  |     return ret; | ||
|  | } | ||
|  | 
 | ||
|  | static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx) | ||
|  | { | ||
|  |     ctx->state = CCM_STATE__CLEAR; | ||
|  |     memset(ctx->y, 0, 16); | ||
|  |     memset(ctx->ctr, 0, 16); | ||
|  | } | ||
|  | 
 | ||
|  | static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     unsigned char i; | ||
|  |     size_t len_left, olen; | ||
|  | 
 | ||
|  |     /* length calculation can be done only after both
 | ||
|  |      * mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed | ||
|  |      */ | ||
|  |     if (!(ctx->state & CCM_STATE__STARTED) || !(ctx->state & CCM_STATE__LENGTHS_SET)) { | ||
|  |         return 0; | ||
|  |     } | ||
|  | 
 | ||
|  |     /* CCM expects non-empty tag.
 | ||
|  |      * CCM* allows empty tag. For CCM* without tag, ignore plaintext length. | ||
|  |      */ | ||
|  |     if (ctx->tag_len == 0) { | ||
|  |         if (ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT || ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) { | ||
|  |             ctx->plaintext_len = 0; | ||
|  |         } else { | ||
|  |             return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     /*
 | ||
|  |      * First block: | ||
|  |      * 0        .. 0        flags | ||
|  |      * 1        .. iv_len   nonce (aka iv)  - set by: mbedtls_ccm_starts() | ||
|  |      * iv_len+1 .. 15       length | ||
|  |      * | ||
|  |      * With flags as (bits): | ||
|  |      * 7        0 | ||
|  |      * 6        add present? | ||
|  |      * 5 .. 3   (t - 2) / 2 | ||
|  |      * 2 .. 0   q - 1 | ||
|  |      */ | ||
|  |     ctx->y[0] |= (ctx->add_len > 0) << 6; | ||
|  |     ctx->y[0] |= ((ctx->tag_len - 2) / 2) << 3; | ||
|  |     ctx->y[0] |= ctx->q - 1; | ||
|  | 
 | ||
|  |     for (i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8) { | ||
|  |         ctx->y[15-i] = MBEDTLS_BYTE_0(len_left); | ||
|  |     } | ||
|  | 
 | ||
|  |     if (len_left > 0) { | ||
|  |         ctx->state |= CCM_STATE__ERROR; | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     /* Start CBC-MAC with first block*/ | ||
|  |     if ((ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) { | ||
|  |         ctx->state |= CCM_STATE__ERROR; | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_starts(mbedtls_ccm_context *ctx, | ||
|  |                        int mode, | ||
|  |                        const unsigned char *iv, | ||
|  |                        size_t iv_len) | ||
|  | { | ||
|  |     /* Also implies q is within bounds */ | ||
|  |     if (iv_len < 7 || iv_len > 13) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     ctx->mode = mode; | ||
|  |     ctx->q = 16 - 1 - (unsigned char) iv_len; | ||
|  | 
 | ||
|  |     /*
 | ||
|  |      * Prepare counter block for encryption: | ||
|  |      * 0        .. 0        flags | ||
|  |      * 1        .. iv_len   nonce (aka iv) | ||
|  |      * iv_len+1 .. 15       counter (initially 1) | ||
|  |      * | ||
|  |      * With flags as (bits): | ||
|  |      * 7 .. 3   0 | ||
|  |      * 2 .. 0   q - 1 | ||
|  |      */ | ||
|  |     memset(ctx->ctr, 0, 16); | ||
|  |     ctx->ctr[0] = ctx->q - 1; | ||
|  |     memcpy(ctx->ctr + 1, iv, iv_len); | ||
|  |     memset(ctx->ctr + 1 + iv_len, 0, ctx->q); | ||
|  |     ctx->ctr[15] = 1; | ||
|  | 
 | ||
|  |     /*
 | ||
|  |      * See ccm_calculate_first_block_if_ready() for block layout description | ||
|  |      */ | ||
|  |     memcpy(ctx->y + 1, iv, iv_len); | ||
|  | 
 | ||
|  |     ctx->state |= CCM_STATE__STARTED; | ||
|  |     return ccm_calculate_first_block_if_ready(ctx); | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx, | ||
|  |                             size_t total_ad_len, | ||
|  |                             size_t plaintext_len, | ||
|  |                             size_t tag_len) | ||
|  | { | ||
|  |     /*
 | ||
|  |      * Check length requirements: SP800-38C A.1 | ||
|  |      * Additional requirement: a < 2^16 - 2^8 to simplify the code. | ||
|  |      * 'length' checked later (when writing it to the first block) | ||
|  |      * | ||
|  |      * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4). | ||
|  |      */ | ||
|  |     if (tag_len == 2 || tag_len > 16 || tag_len % 2 != 0) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (total_ad_len >= 0xFF00) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     ctx->plaintext_len = plaintext_len; | ||
|  |     ctx->add_len = total_ad_len; | ||
|  |     ctx->tag_len = tag_len; | ||
|  |     ctx->processed = 0; | ||
|  | 
 | ||
|  |     ctx->state |= CCM_STATE__LENGTHS_SET; | ||
|  |     return ccm_calculate_first_block_if_ready(ctx); | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx, | ||
|  |                           const unsigned char *add, | ||
|  |                           size_t add_len) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     size_t olen, use_len, offset; | ||
|  | 
 | ||
|  |     if (ctx->state & CCM_STATE__ERROR) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (add_len > 0) { | ||
|  |         if (ctx->state & CCM_STATE__AUTH_DATA_FINISHED) { | ||
|  |             return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |         } | ||
|  | 
 | ||
|  |         if (!(ctx->state & CCM_STATE__AUTH_DATA_STARTED)) { | ||
|  |             if (add_len > ctx->add_len) { | ||
|  |                 return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |             } | ||
|  | 
 | ||
|  |             ctx->y[0] ^= (unsigned char) ((ctx->add_len >> 8) & 0xFF); | ||
|  |             ctx->y[1] ^= (unsigned char) ((ctx->add_len) & 0xFF); | ||
|  | 
 | ||
|  |             ctx->state |= CCM_STATE__AUTH_DATA_STARTED; | ||
|  |         } else if (ctx->processed + add_len > ctx->add_len) { | ||
|  |             return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |         } | ||
|  | 
 | ||
|  |         while (add_len > 0) { | ||
|  |             offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1]
 | ||
|  |                                                  * holding total auth data length */ | ||
|  |             use_len = 16 - offset; | ||
|  | 
 | ||
|  |             if (use_len > add_len) { | ||
|  |                 use_len = add_len; | ||
|  |             } | ||
|  | 
 | ||
|  |             mbedtls_xor(ctx->y + offset, ctx->y + offset, add, use_len); | ||
|  | 
 | ||
|  |             ctx->processed += use_len; | ||
|  |             add_len -= use_len; | ||
|  |             add += use_len; | ||
|  | 
 | ||
|  |             if (use_len + offset == 16 || ctx->processed == ctx->add_len) { | ||
|  |                 if ((ret = | ||
|  |                          mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) { | ||
|  |                     ctx->state |= CCM_STATE__ERROR; | ||
|  |                     return ret; | ||
|  |                 } | ||
|  |             } | ||
|  |         } | ||
|  | 
 | ||
|  |         if (ctx->processed == ctx->add_len) { | ||
|  |             ctx->state |= CCM_STATE__AUTH_DATA_FINISHED; | ||
|  |             ctx->processed = 0; // prepare for mbedtls_ccm_update()
 | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_update(mbedtls_ccm_context *ctx, | ||
|  |                        const unsigned char *input, size_t input_len, | ||
|  |                        unsigned char *output, size_t output_size, | ||
|  |                        size_t *output_len) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     unsigned char i; | ||
|  |     size_t use_len, offset, olen; | ||
|  | 
 | ||
|  |     unsigned char local_output[16]; | ||
|  | 
 | ||
|  |     if (ctx->state & CCM_STATE__ERROR) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     /* Check against plaintext length only if performing operation with
 | ||
|  |      * authentication | ||
|  |      */ | ||
|  |     if (ctx->tag_len != 0 && ctx->processed + input_len > ctx->plaintext_len) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (output_size < input_len) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  |     *output_len = input_len; | ||
|  | 
 | ||
|  |     ret = 0; | ||
|  | 
 | ||
|  |     while (input_len > 0) { | ||
|  |         offset = ctx->processed % 16; | ||
|  | 
 | ||
|  |         use_len = 16 - offset; | ||
|  | 
 | ||
|  |         if (use_len > input_len) { | ||
|  |             use_len = input_len; | ||
|  |         } | ||
|  | 
 | ||
|  |         ctx->processed += use_len; | ||
|  | 
 | ||
|  |         if (ctx->mode == MBEDTLS_CCM_ENCRYPT || \ | ||
|  |             ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT) { | ||
|  |             mbedtls_xor(ctx->y + offset, ctx->y + offset, input, use_len); | ||
|  | 
 | ||
|  |             if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { | ||
|  |                 if ((ret = | ||
|  |                          mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) { | ||
|  |                     ctx->state |= CCM_STATE__ERROR; | ||
|  |                     goto exit; | ||
|  |                 } | ||
|  |             } | ||
|  | 
 | ||
|  |             ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, output); | ||
|  |             if (ret != 0) { | ||
|  |                 goto exit; | ||
|  |             } | ||
|  |         } | ||
|  | 
 | ||
|  |         if (ctx->mode == MBEDTLS_CCM_DECRYPT || \ | ||
|  |             ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) { | ||
|  |             /* Since output may be in shared memory, we cannot be sure that
 | ||
|  |              * it will contain what we wrote to it. Therefore, we should avoid using | ||
|  |              * it as input to any operations. | ||
|  |              * Write decrypted data to local_output to avoid using output variable as | ||
|  |              * input in the XOR operation for Y. | ||
|  |              */ | ||
|  |             ret = mbedtls_ccm_crypt(ctx, offset, use_len, input, local_output); | ||
|  |             if (ret != 0) { | ||
|  |                 goto exit; | ||
|  |             } | ||
|  | 
 | ||
|  |             mbedtls_xor(ctx->y + offset, ctx->y + offset, local_output, use_len); | ||
|  | 
 | ||
|  |             memcpy(output, local_output, use_len); | ||
|  |             mbedtls_platform_zeroize(local_output, 16); | ||
|  | 
 | ||
|  |             if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { | ||
|  |                 if ((ret = | ||
|  |                          mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen)) != 0) { | ||
|  |                     ctx->state |= CCM_STATE__ERROR; | ||
|  |                     goto exit; | ||
|  |                 } | ||
|  |             } | ||
|  |         } | ||
|  | 
 | ||
|  |         if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) { | ||
|  |             for (i = 0; i < ctx->q; i++) { | ||
|  |                 if (++(ctx->ctr)[15-i] != 0) { | ||
|  |                     break; | ||
|  |                 } | ||
|  |             } | ||
|  |         } | ||
|  | 
 | ||
|  |         input_len -= use_len; | ||
|  |         input += use_len; | ||
|  |         output += use_len; | ||
|  |     } | ||
|  | 
 | ||
|  | exit: | ||
|  |     mbedtls_platform_zeroize(local_output, 16); | ||
|  | 
 | ||
|  |     return ret; | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_finish(mbedtls_ccm_context *ctx, | ||
|  |                        unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     unsigned char i; | ||
|  | 
 | ||
|  |     if (ctx->state & CCM_STATE__ERROR) { | ||
|  |         return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (ctx->add_len > 0 && !(ctx->state & CCM_STATE__AUTH_DATA_FINISHED)) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (ctx->plaintext_len > 0 && ctx->processed != ctx->plaintext_len) { | ||
|  |         return MBEDTLS_ERR_CCM_BAD_INPUT; | ||
|  |     } | ||
|  | 
 | ||
|  |     /*
 | ||
|  |      * Authentication: reset counter and crypt/mask internal tag | ||
|  |      */ | ||
|  |     for (i = 0; i < ctx->q; i++) { | ||
|  |         ctx->ctr[15-i] = 0; | ||
|  |     } | ||
|  | 
 | ||
|  |     ret = mbedtls_ccm_crypt(ctx, 0, 16, ctx->y, ctx->y); | ||
|  |     if (ret != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  |     if (tag != NULL) { | ||
|  |         memcpy(tag, ctx->y, tag_len); | ||
|  |     } | ||
|  |     mbedtls_ccm_clear_state(ctx); | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Authenticated encryption or decryption | ||
|  |  */ | ||
|  | static int ccm_auth_crypt(mbedtls_ccm_context *ctx, int mode, size_t length, | ||
|  |                           const unsigned char *iv, size_t iv_len, | ||
|  |                           const unsigned char *add, size_t add_len, | ||
|  |                           const unsigned char *input, unsigned char *output, | ||
|  |                           unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     size_t olen; | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_starts(ctx, mode, iv, iv_len)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_set_lengths(ctx, add_len, length, tag_len)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_update_ad(ctx, add, add_len)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_update(ctx, input, length, | ||
|  |                                   output, length, &olen)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_finish(ctx, tag, tag_len)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Authenticated encryption | ||
|  |  */ | ||
|  | int mbedtls_ccm_star_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length, | ||
|  |                                      const unsigned char *iv, size_t iv_len, | ||
|  |                                      const unsigned char *add, size_t add_len, | ||
|  |                                      const unsigned char *input, unsigned char *output, | ||
|  |                                      unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     return ccm_auth_crypt(ctx, MBEDTLS_CCM_STAR_ENCRYPT, length, iv, iv_len, | ||
|  |                           add, add_len, input, output, tag, tag_len); | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length, | ||
|  |                                 const unsigned char *iv, size_t iv_len, | ||
|  |                                 const unsigned char *add, size_t add_len, | ||
|  |                                 const unsigned char *input, unsigned char *output, | ||
|  |                                 unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     return ccm_auth_crypt(ctx, MBEDTLS_CCM_ENCRYPT, length, iv, iv_len, | ||
|  |                           add, add_len, input, output, tag, tag_len); | ||
|  | } | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Authenticated decryption | ||
|  |  */ | ||
|  | static int mbedtls_ccm_compare_tags(const unsigned char *tag1, | ||
|  |                                     const unsigned char *tag2, | ||
|  |                                     size_t tag_len) | ||
|  | { | ||
|  |     unsigned char i; | ||
|  |     int diff; | ||
|  | 
 | ||
|  |     /* Check tag in "constant-time" */ | ||
|  |     for (diff = 0, i = 0; i < tag_len; i++) { | ||
|  |         diff |= tag1[i] ^ tag2[i]; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (diff != 0) { | ||
|  |         return MBEDTLS_ERR_CCM_AUTH_FAILED; | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | static int ccm_auth_decrypt(mbedtls_ccm_context *ctx, int mode, size_t length, | ||
|  |                             const unsigned char *iv, size_t iv_len, | ||
|  |                             const unsigned char *add, size_t add_len, | ||
|  |                             const unsigned char *input, unsigned char *output, | ||
|  |                             const unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  |     unsigned char check_tag[16]; | ||
|  | 
 | ||
|  |     if ((ret = ccm_auth_crypt(ctx, mode, length, | ||
|  |                               iv, iv_len, add, add_len, | ||
|  |                               input, output, check_tag, tag_len)) != 0) { | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     if ((ret = mbedtls_ccm_compare_tags(tag, check_tag, tag_len)) != 0) { | ||
|  |         mbedtls_platform_zeroize(output, length); | ||
|  |         return ret; | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_star_auth_decrypt(mbedtls_ccm_context *ctx, size_t length, | ||
|  |                                   const unsigned char *iv, size_t iv_len, | ||
|  |                                   const unsigned char *add, size_t add_len, | ||
|  |                                   const unsigned char *input, unsigned char *output, | ||
|  |                                   const unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     return ccm_auth_decrypt(ctx, MBEDTLS_CCM_STAR_DECRYPT, length, | ||
|  |                             iv, iv_len, add, add_len, | ||
|  |                             input, output, tag, tag_len); | ||
|  | } | ||
|  | 
 | ||
|  | int mbedtls_ccm_auth_decrypt(mbedtls_ccm_context *ctx, size_t length, | ||
|  |                              const unsigned char *iv, size_t iv_len, | ||
|  |                              const unsigned char *add, size_t add_len, | ||
|  |                              const unsigned char *input, unsigned char *output, | ||
|  |                              const unsigned char *tag, size_t tag_len) | ||
|  | { | ||
|  |     return ccm_auth_decrypt(ctx, MBEDTLS_CCM_DECRYPT, length, | ||
|  |                             iv, iv_len, add, add_len, | ||
|  |                             input, output, tag, tag_len); | ||
|  | } | ||
|  | #endif /* !MBEDTLS_CCM_ALT */
 | ||
|  | 
 | ||
|  | #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
 | ||
|  | /*
 | ||
|  |  * Examples 1 to 3 from SP800-38C Appendix C | ||
|  |  */ | ||
|  | 
 | ||
|  | #define NB_TESTS 3
 | ||
|  | #define CCM_SELFTEST_PT_MAX_LEN 24
 | ||
|  | #define CCM_SELFTEST_CT_MAX_LEN 32
 | ||
|  | /*
 | ||
|  |  * The data is the same for all tests, only the used length changes | ||
|  |  */ | ||
|  | static const unsigned char key_test_data[] = { | ||
|  |     0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, | ||
|  |     0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f | ||
|  | }; | ||
|  | 
 | ||
|  | static const unsigned char iv_test_data[] = { | ||
|  |     0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, | ||
|  |     0x18, 0x19, 0x1a, 0x1b | ||
|  | }; | ||
|  | 
 | ||
|  | static const unsigned char ad_test_data[] = { | ||
|  |     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, | ||
|  |     0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, | ||
|  |     0x10, 0x11, 0x12, 0x13 | ||
|  | }; | ||
|  | 
 | ||
|  | static const unsigned char msg_test_data[CCM_SELFTEST_PT_MAX_LEN] = { | ||
|  |     0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, | ||
|  |     0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, | ||
|  |     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, | ||
|  | }; | ||
|  | 
 | ||
|  | static const size_t iv_len_test_data[NB_TESTS] = { 7, 8,  12 }; | ||
|  | static const size_t add_len_test_data[NB_TESTS] = { 8, 16, 20 }; | ||
|  | static const size_t msg_len_test_data[NB_TESTS] = { 4, 16, 24 }; | ||
|  | static const size_t tag_len_test_data[NB_TESTS] = { 4, 6,  8  }; | ||
|  | 
 | ||
|  | static const unsigned char res_test_data[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = { | ||
|  |     {   0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d }, | ||
|  |     {   0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62, | ||
|  |         0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d, | ||
|  |         0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd }, | ||
|  |     {   0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a, | ||
|  |         0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b, | ||
|  |         0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5, | ||
|  |         0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 } | ||
|  | }; | ||
|  | 
 | ||
|  | int mbedtls_ccm_self_test(int verbose) | ||
|  | { | ||
|  |     mbedtls_ccm_context ctx; | ||
|  |     /*
 | ||
|  |      * Some hardware accelerators require the input and output buffers | ||
|  |      * would be in RAM, because the flash is not accessible. | ||
|  |      * Use buffers on the stack to hold the test vectors data. | ||
|  |      */ | ||
|  |     unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN]; | ||
|  |     unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN]; | ||
|  |     size_t i; | ||
|  |     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; | ||
|  | 
 | ||
|  |     mbedtls_ccm_init(&ctx); | ||
|  | 
 | ||
|  |     if (mbedtls_ccm_setkey(&ctx, MBEDTLS_CIPHER_ID_AES, key_test_data, | ||
|  |                            8 * sizeof(key_test_data)) != 0) { | ||
|  |         if (verbose != 0) { | ||
|  |             mbedtls_printf("  CCM: setup failed"); | ||
|  |         } | ||
|  | 
 | ||
|  |         return 1; | ||
|  |     } | ||
|  | 
 | ||
|  |     for (i = 0; i < NB_TESTS; i++) { | ||
|  |         if (verbose != 0) { | ||
|  |             mbedtls_printf("  CCM-AES #%u: ", (unsigned int) i + 1); | ||
|  |         } | ||
|  | 
 | ||
|  |         memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN); | ||
|  |         memset(ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN); | ||
|  |         memcpy(plaintext, msg_test_data, msg_len_test_data[i]); | ||
|  | 
 | ||
|  |         ret = mbedtls_ccm_encrypt_and_tag(&ctx, msg_len_test_data[i], | ||
|  |                                           iv_test_data, iv_len_test_data[i], | ||
|  |                                           ad_test_data, add_len_test_data[i], | ||
|  |                                           plaintext, ciphertext, | ||
|  |                                           ciphertext + msg_len_test_data[i], | ||
|  |                                           tag_len_test_data[i]); | ||
|  | 
 | ||
|  |         if (ret != 0 || | ||
|  |             memcmp(ciphertext, res_test_data[i], | ||
|  |                    msg_len_test_data[i] + tag_len_test_data[i]) != 0) { | ||
|  |             if (verbose != 0) { | ||
|  |                 mbedtls_printf("failed\n"); | ||
|  |             } | ||
|  | 
 | ||
|  |             return 1; | ||
|  |         } | ||
|  |         memset(plaintext, 0, CCM_SELFTEST_PT_MAX_LEN); | ||
|  | 
 | ||
|  |         ret = mbedtls_ccm_auth_decrypt(&ctx, msg_len_test_data[i], | ||
|  |                                        iv_test_data, iv_len_test_data[i], | ||
|  |                                        ad_test_data, add_len_test_data[i], | ||
|  |                                        ciphertext, plaintext, | ||
|  |                                        ciphertext + msg_len_test_data[i], | ||
|  |                                        tag_len_test_data[i]); | ||
|  | 
 | ||
|  |         if (ret != 0 || | ||
|  |             memcmp(plaintext, msg_test_data, msg_len_test_data[i]) != 0) { | ||
|  |             if (verbose != 0) { | ||
|  |                 mbedtls_printf("failed\n"); | ||
|  |             } | ||
|  | 
 | ||
|  |             return 1; | ||
|  |         } | ||
|  | 
 | ||
|  |         if (verbose != 0) { | ||
|  |             mbedtls_printf("passed\n"); | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     mbedtls_ccm_free(&ctx); | ||
|  | 
 | ||
|  |     if (verbose != 0) { | ||
|  |         mbedtls_printf("\n"); | ||
|  |     } | ||
|  | 
 | ||
|  |     return 0; | ||
|  | } | ||
|  | 
 | ||
|  | #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
 | ||
|  | 
 | ||
|  | #endif /* MBEDTLS_CCM_C */
 |