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			765 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			765 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  NIST SP800-38C compliant CCM implementation
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|  *
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|  *  Copyright The Mbed TLS Contributors
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|  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
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|  */
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| 
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| /*
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|  * Definition of CCM:
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|  * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
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|  * RFC 3610 "Counter with CBC-MAC (CCM)"
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|  *
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|  * Related:
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|  * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
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|  */
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| 
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| #include "common.h"
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| 
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| #if defined(MBEDTLS_CCM_C)
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| 
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| #include "mbedtls/ccm.h"
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| #include "mbedtls/platform_util.h"
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| #include "mbedtls/error.h"
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| #include "mbedtls/constant_time.h"
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| 
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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| #include "block_cipher_internal.h"
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| #endif
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| 
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| #include <string.h>
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| 
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| #if defined(MBEDTLS_PLATFORM_C)
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| #include "mbedtls/platform.h"
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| #else
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| #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
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| #include <stdio.h>
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| #define mbedtls_printf printf
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| #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
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| #endif /* MBEDTLS_PLATFORM_C */
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| 
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| #if !defined(MBEDTLS_CCM_ALT)
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| 
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| 
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| /*
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|  * Initialize context
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|  */
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| void mbedtls_ccm_init(mbedtls_ccm_context *ctx)
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| {
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|     memset(ctx, 0, sizeof(mbedtls_ccm_context));
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| }
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| 
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| int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx,
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|                        mbedtls_cipher_id_t cipher,
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|                        const unsigned char *key,
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|                        unsigned int keybits)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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| 
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|     mbedtls_block_cipher_free(&ctx->block_cipher_ctx);
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| 
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|     if ((ret = mbedtls_block_cipher_setup(&ctx->block_cipher_ctx, cipher)) != 0) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     if ((ret = mbedtls_block_cipher_setkey(&ctx->block_cipher_ctx, key, keybits)) != 0) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| #else
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|     const mbedtls_cipher_info_t *cipher_info;
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| 
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|     cipher_info = mbedtls_cipher_info_from_values(cipher, keybits,
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|                                                   MBEDTLS_MODE_ECB);
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|     if (cipher_info == NULL) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     if (mbedtls_cipher_info_get_block_size(cipher_info) != 16) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     mbedtls_cipher_free(&ctx->cipher_ctx);
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| 
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|     if ((ret = mbedtls_cipher_setup(&ctx->cipher_ctx, cipher_info)) != 0) {
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|         return ret;
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|     }
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| 
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|     if ((ret = mbedtls_cipher_setkey(&ctx->cipher_ctx, key, keybits,
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|                                      MBEDTLS_ENCRYPT)) != 0) {
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|         return ret;
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|     }
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| #endif
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| 
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|     return ret;
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| }
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| 
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| /*
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|  * Free context
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|  */
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| void mbedtls_ccm_free(mbedtls_ccm_context *ctx)
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| {
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|     if (ctx == NULL) {
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|         return;
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|     }
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|     mbedtls_block_cipher_free(&ctx->block_cipher_ctx);
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| #else
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|     mbedtls_cipher_free(&ctx->cipher_ctx);
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| #endif
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|     mbedtls_platform_zeroize(ctx, sizeof(mbedtls_ccm_context));
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| }
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| 
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| #define CCM_STATE__CLEAR                0
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| #define CCM_STATE__STARTED              (1 << 0)
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| #define CCM_STATE__LENGTHS_SET          (1 << 1)
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| #define CCM_STATE__AUTH_DATA_STARTED    (1 << 2)
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| #define CCM_STATE__AUTH_DATA_FINISHED   (1 << 3)
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| #define CCM_STATE__ERROR                (1 << 4)
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| 
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| /*
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|  * Encrypt or decrypt a partial block with CTR
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|  */
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| static int mbedtls_ccm_crypt(mbedtls_ccm_context *ctx,
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|                              size_t offset, size_t use_len,
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|                              const unsigned char *input,
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|                              unsigned char *output)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char tmp_buf[16] = { 0 };
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| 
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|     ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->ctr, tmp_buf);
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| #else
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|     size_t olen = 0;
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|     ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->ctr, 16, tmp_buf, &olen);
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| #endif
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|     if (ret != 0) {
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|         ctx->state |= CCM_STATE__ERROR;
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|         mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
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|         return ret;
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|     }
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| 
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|     mbedtls_xor(output, input, tmp_buf + offset, use_len);
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| 
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|     mbedtls_platform_zeroize(tmp_buf, sizeof(tmp_buf));
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|     return ret;
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| }
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| 
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| static void mbedtls_ccm_clear_state(mbedtls_ccm_context *ctx)
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| {
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|     ctx->state = CCM_STATE__CLEAR;
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|     memset(ctx->y, 0, 16);
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|     memset(ctx->ctr, 0, 16);
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| }
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| 
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| static int ccm_calculate_first_block_if_ready(mbedtls_ccm_context *ctx)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char i;
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|     size_t len_left;
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| #if !defined(MBEDTLS_BLOCK_CIPHER_C)
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|     size_t olen;
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| #endif
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| 
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|     /* length calculation can be done only after both
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|      * mbedtls_ccm_starts() and mbedtls_ccm_set_lengths() have been executed
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|      */
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|     if (!(ctx->state & CCM_STATE__STARTED) || !(ctx->state & CCM_STATE__LENGTHS_SET)) {
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|         return 0;
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|     }
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| 
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|     /* CCM expects non-empty tag.
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|      * CCM* allows empty tag. For CCM* without tag, the tag calculation is skipped.
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|      */
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|     if (ctx->tag_len == 0) {
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|         if (ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT || ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
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|             ctx->plaintext_len = 0;
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|             return 0;
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|         } else {
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|             return MBEDTLS_ERR_CCM_BAD_INPUT;
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|         }
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|     }
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| 
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|     /*
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|      * First block:
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|      * 0        .. 0        flags
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|      * 1        .. iv_len   nonce (aka iv)  - set by: mbedtls_ccm_starts()
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|      * iv_len+1 .. 15       length
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|      *
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|      * With flags as (bits):
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|      * 7        0
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|      * 6        add present?
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|      * 5 .. 3   (t - 2) / 2
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|      * 2 .. 0   q - 1
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|      */
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|     ctx->y[0] |= (ctx->add_len > 0) << 6;
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|     ctx->y[0] |= ((ctx->tag_len - 2) / 2) << 3;
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|     ctx->y[0] |= ctx->q - 1;
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| 
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|     for (i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8) {
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|         ctx->y[15-i] = MBEDTLS_BYTE_0(len_left);
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|     }
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| 
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|     if (len_left > 0) {
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|         ctx->state |= CCM_STATE__ERROR;
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     /* Start CBC-MAC with first block*/
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|     ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y);
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| #else
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|     ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen);
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| #endif
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|     if (ret != 0) {
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|         ctx->state |= CCM_STATE__ERROR;
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|         return ret;
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|     }
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| 
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|     return 0;
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| }
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| 
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| int mbedtls_ccm_starts(mbedtls_ccm_context *ctx,
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|                        int mode,
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|                        const unsigned char *iv,
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|                        size_t iv_len)
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| {
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|     /* Also implies q is within bounds */
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|     if (iv_len < 7 || iv_len > 13) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     ctx->mode = mode;
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|     ctx->q = 16 - 1 - (unsigned char) iv_len;
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| 
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|     /*
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|      * Prepare counter block for encryption:
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|      * 0        .. 0        flags
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|      * 1        .. iv_len   nonce (aka iv)
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|      * iv_len+1 .. 15       counter (initially 1)
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|      *
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|      * With flags as (bits):
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|      * 7 .. 3   0
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|      * 2 .. 0   q - 1
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|      */
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|     memset(ctx->ctr, 0, 16);
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|     ctx->ctr[0] = ctx->q - 1;
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|     memcpy(ctx->ctr + 1, iv, iv_len);
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|     memset(ctx->ctr + 1 + iv_len, 0, ctx->q);
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|     ctx->ctr[15] = 1;
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| 
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|     /*
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|      * See ccm_calculate_first_block_if_ready() for block layout description
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|      */
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|     memcpy(ctx->y + 1, iv, iv_len);
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| 
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|     ctx->state |= CCM_STATE__STARTED;
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|     return ccm_calculate_first_block_if_ready(ctx);
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| }
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| 
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| int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx,
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|                             size_t total_ad_len,
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|                             size_t plaintext_len,
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|                             size_t tag_len)
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| {
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|     /*
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|      * Check length requirements: SP800-38C A.1
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|      * Additional requirement: a < 2^16 - 2^8 to simplify the code.
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|      * 'length' checked later (when writing it to the first block)
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|      *
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|      * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
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|      */
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|     if (tag_len == 2 || tag_len > 16 || tag_len % 2 != 0) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     if (total_ad_len >= 0xFF00) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     ctx->plaintext_len = plaintext_len;
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|     ctx->add_len = total_ad_len;
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|     ctx->tag_len = tag_len;
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|     ctx->processed = 0;
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| 
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|     ctx->state |= CCM_STATE__LENGTHS_SET;
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|     return ccm_calculate_first_block_if_ready(ctx);
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| }
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| 
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| int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx,
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|                           const unsigned char *add,
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|                           size_t add_len)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t use_len, offset;
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| #if !defined(MBEDTLS_BLOCK_CIPHER_C)
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|     size_t olen;
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| #endif
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| 
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|     if (ctx->state & CCM_STATE__ERROR) {
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|         return MBEDTLS_ERR_CCM_BAD_INPUT;
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|     }
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| 
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|     if (add_len > 0) {
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|         if (ctx->state & CCM_STATE__AUTH_DATA_FINISHED) {
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|             return MBEDTLS_ERR_CCM_BAD_INPUT;
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|         }
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| 
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|         if (!(ctx->state & CCM_STATE__AUTH_DATA_STARTED)) {
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|             if (add_len > ctx->add_len) {
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|                 return MBEDTLS_ERR_CCM_BAD_INPUT;
 | |
|             }
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| 
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|             ctx->y[0] ^= (unsigned char) ((ctx->add_len >> 8) & 0xFF);
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|             ctx->y[1] ^= (unsigned char) ((ctx->add_len) & 0xFF);
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| 
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|             ctx->state |= CCM_STATE__AUTH_DATA_STARTED;
 | |
|         } else if (ctx->processed + add_len > ctx->add_len) {
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|             return MBEDTLS_ERR_CCM_BAD_INPUT;
 | |
|         }
 | |
| 
 | |
|         while (add_len > 0) {
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|             offset = (ctx->processed + 2) % 16; /* account for y[0] and y[1]
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|                                                  * holding total auth data length */
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|             use_len = 16 - offset;
 | |
| 
 | |
|             if (use_len > add_len) {
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|                 use_len = add_len;
 | |
|             }
 | |
| 
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|             mbedtls_xor(ctx->y + offset, ctx->y + offset, add, use_len);
 | |
| 
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|             ctx->processed += use_len;
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|             add_len -= use_len;
 | |
|             add += use_len;
 | |
| 
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|             if (use_len + offset == 16 || ctx->processed == ctx->add_len) {
 | |
| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|                 ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y);
 | |
| #else
 | |
|                 ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen);
 | |
| #endif
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|                 if (ret != 0) {
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|                     ctx->state |= CCM_STATE__ERROR;
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|                     return ret;
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|                 }
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|             }
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|         }
 | |
| 
 | |
|         if (ctx->processed == ctx->add_len) {
 | |
|             ctx->state |= CCM_STATE__AUTH_DATA_FINISHED;
 | |
|             ctx->processed = 0; // prepare for mbedtls_ccm_update()
 | |
|         }
 | |
|     }
 | |
| 
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|     return 0;
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| }
 | |
| 
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| int mbedtls_ccm_update(mbedtls_ccm_context *ctx,
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|                        const unsigned char *input, size_t input_len,
 | |
|                        unsigned char *output, size_t output_size,
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|                        size_t *output_len)
 | |
| {
 | |
|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 | |
|     unsigned char i;
 | |
|     size_t use_len, offset;
 | |
| #if !defined(MBEDTLS_BLOCK_CIPHER_C)
 | |
|     size_t olen;
 | |
| #endif
 | |
| 
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|     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) {
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|             use_len = input_len;
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|         }
 | |
| 
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|         ctx->processed += use_len;
 | |
| 
 | |
|         if (ctx->mode == MBEDTLS_CCM_ENCRYPT || \
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|             ctx->mode == MBEDTLS_CCM_STAR_ENCRYPT) {
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|             mbedtls_xor(ctx->y + offset, ctx->y + offset, input, use_len);
 | |
| 
 | |
|             if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) {
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| #if defined(MBEDTLS_BLOCK_CIPHER_C)
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|                 ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y);
 | |
| #else
 | |
|                 ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen);
 | |
| #endif
 | |
|                 if (ret != 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 || \
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|             ctx->mode == MBEDTLS_CCM_STAR_DECRYPT) {
 | |
|             /* Since output may be in shared memory, we cannot be sure that
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|              * it will contain what we wrote to it. Therefore, we should avoid using
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|              * it as input to any operations.
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|              * Write decrypted data to local_output to avoid using output variable as
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|              * input in the XOR operation for Y.
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|              */
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|             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);
 | |
| 
 | |
|             if (use_len + offset == 16 || ctx->processed == ctx->plaintext_len) {
 | |
| #if defined(MBEDTLS_BLOCK_CIPHER_C)
 | |
|                 ret = mbedtls_block_cipher_encrypt(&ctx->block_cipher_ctx, ctx->y, ctx->y);
 | |
| #else
 | |
|                 ret = mbedtls_cipher_update(&ctx->cipher_ctx, ctx->y, 16, ctx->y, &olen);
 | |
| #endif
 | |
|                 if (ret != 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)
 | |
| {
 | |
|     /* Check tag in "constant-time" */
 | |
|     int diff = mbedtls_ct_memcmp(tag1, tag2, tag_len);
 | |
| 
 | |
|     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_CCM_GCM_CAN_AES)
 | |
| /*
 | |
|  * 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 */
 |