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	 40fa684c18
			
		
	
	
		40fa684c18
		
	
	
	
	
		
			
			Keep module compatibility with mbedtls 2.x (old LTS branch). A patch has been added to allow compiling after removing all the `psa_*` files from the library folder (will look into upstreaming it). Note: mbedTLS 3.6 finally enabled TLSv1.3 by default, but it requires some module changes, and to enable PSA crypto (new "standard" API specification), so it might be best done in a separate commit/PR.
		
			
				
	
	
		
			478 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			478 lines
		
	
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /**
 | |
|  * \file chachapoly.c
 | |
|  *
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|  * \brief ChaCha20-Poly1305 AEAD construction based on RFC 7539.
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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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| #include "common.h"
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| 
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| #if defined(MBEDTLS_CHACHAPOLY_C)
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| 
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| #include "mbedtls/chachapoly.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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| #include <string.h>
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| 
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| #include "mbedtls/platform.h"
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| 
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| #if !defined(MBEDTLS_CHACHAPOLY_ALT)
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| 
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| #define CHACHAPOLY_STATE_INIT       (0)
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| #define CHACHAPOLY_STATE_AAD        (1)
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| #define CHACHAPOLY_STATE_CIPHERTEXT (2)   /* Encrypting or decrypting */
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| #define CHACHAPOLY_STATE_FINISHED   (3)
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| 
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| /**
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|  * \brief           Adds nul bytes to pad the AAD for Poly1305.
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|  *
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|  * \param ctx       The ChaCha20-Poly1305 context.
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|  */
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| static int chachapoly_pad_aad(mbedtls_chachapoly_context *ctx)
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| {
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|     uint32_t partial_block_len = (uint32_t) (ctx->aad_len % 16U);
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|     unsigned char zeroes[15];
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| 
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|     if (partial_block_len == 0U) {
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|         return 0;
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|     }
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| 
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|     memset(zeroes, 0, sizeof(zeroes));
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| 
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|     return mbedtls_poly1305_update(&ctx->poly1305_ctx,
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|                                    zeroes,
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|                                    16U - partial_block_len);
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| }
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| 
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| /**
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|  * \brief           Adds nul bytes to pad the ciphertext for Poly1305.
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|  *
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|  * \param ctx       The ChaCha20-Poly1305 context.
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|  */
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| static int chachapoly_pad_ciphertext(mbedtls_chachapoly_context *ctx)
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| {
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|     uint32_t partial_block_len = (uint32_t) (ctx->ciphertext_len % 16U);
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|     unsigned char zeroes[15];
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| 
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|     if (partial_block_len == 0U) {
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|         return 0;
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|     }
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| 
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|     memset(zeroes, 0, sizeof(zeroes));
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|     return mbedtls_poly1305_update(&ctx->poly1305_ctx,
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|                                    zeroes,
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|                                    16U - partial_block_len);
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| }
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| 
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| void mbedtls_chachapoly_init(mbedtls_chachapoly_context *ctx)
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| {
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|     mbedtls_chacha20_init(&ctx->chacha20_ctx);
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|     mbedtls_poly1305_init(&ctx->poly1305_ctx);
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|     ctx->aad_len        = 0U;
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|     ctx->ciphertext_len = 0U;
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|     ctx->state          = CHACHAPOLY_STATE_INIT;
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|     ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
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| }
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| 
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| void mbedtls_chachapoly_free(mbedtls_chachapoly_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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| 
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|     mbedtls_chacha20_free(&ctx->chacha20_ctx);
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|     mbedtls_poly1305_free(&ctx->poly1305_ctx);
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|     ctx->aad_len        = 0U;
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|     ctx->ciphertext_len = 0U;
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|     ctx->state          = CHACHAPOLY_STATE_INIT;
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|     ctx->mode           = MBEDTLS_CHACHAPOLY_ENCRYPT;
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| }
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| 
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| int mbedtls_chachapoly_setkey(mbedtls_chachapoly_context *ctx,
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|                               const unsigned char key[32])
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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| 
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|     ret = mbedtls_chacha20_setkey(&ctx->chacha20_ctx, key);
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| 
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|     return ret;
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| }
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| 
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| int mbedtls_chachapoly_starts(mbedtls_chachapoly_context *ctx,
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|                               const unsigned char nonce[12],
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|                               mbedtls_chachapoly_mode_t mode)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char poly1305_key[64];
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| 
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|     /* Set counter = 0, will be update to 1 when generating Poly1305 key */
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|     ret = mbedtls_chacha20_starts(&ctx->chacha20_ctx, nonce, 0U);
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|     if (ret != 0) {
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|         goto cleanup;
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|     }
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| 
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|     /* Generate the Poly1305 key by getting the ChaCha20 keystream output with
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|      * counter = 0.  This is the same as encrypting a buffer of zeroes.
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|      * Only the first 256-bits (32 bytes) of the key is used for Poly1305.
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|      * The other 256 bits are discarded.
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|      */
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|     memset(poly1305_key, 0, sizeof(poly1305_key));
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|     ret = mbedtls_chacha20_update(&ctx->chacha20_ctx, sizeof(poly1305_key),
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|                                   poly1305_key, poly1305_key);
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|     if (ret != 0) {
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|         goto cleanup;
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|     }
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| 
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|     ret = mbedtls_poly1305_starts(&ctx->poly1305_ctx, poly1305_key);
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| 
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|     if (ret == 0) {
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|         ctx->aad_len        = 0U;
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|         ctx->ciphertext_len = 0U;
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|         ctx->state          = CHACHAPOLY_STATE_AAD;
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|         ctx->mode           = mode;
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|     }
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| 
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| cleanup:
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|     mbedtls_platform_zeroize(poly1305_key, 64U);
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|     return ret;
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| }
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| 
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| int mbedtls_chachapoly_update_aad(mbedtls_chachapoly_context *ctx,
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|                                   const unsigned char *aad,
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|                                   size_t aad_len)
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| {
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|     if (ctx->state != CHACHAPOLY_STATE_AAD) {
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|         return MBEDTLS_ERR_CHACHAPOLY_BAD_STATE;
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|     }
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| 
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|     ctx->aad_len += aad_len;
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| 
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|     return mbedtls_poly1305_update(&ctx->poly1305_ctx, aad, aad_len);
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| }
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| 
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| int mbedtls_chachapoly_update(mbedtls_chachapoly_context *ctx,
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|                               size_t 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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| 
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|     if ((ctx->state != CHACHAPOLY_STATE_AAD) &&
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|         (ctx->state != CHACHAPOLY_STATE_CIPHERTEXT)) {
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|         return MBEDTLS_ERR_CHACHAPOLY_BAD_STATE;
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|     }
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| 
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|     if (ctx->state == CHACHAPOLY_STATE_AAD) {
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|         ctx->state = CHACHAPOLY_STATE_CIPHERTEXT;
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| 
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|         ret = chachapoly_pad_aad(ctx);
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|         if (ret != 0) {
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|             return ret;
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|         }
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|     }
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| 
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|     ctx->ciphertext_len += len;
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| 
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|     if (ctx->mode == MBEDTLS_CHACHAPOLY_ENCRYPT) {
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|         ret = mbedtls_chacha20_update(&ctx->chacha20_ctx, len, input, output);
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|         if (ret != 0) {
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|             return ret;
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|         }
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| 
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|         ret = mbedtls_poly1305_update(&ctx->poly1305_ctx, output, len);
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|         if (ret != 0) {
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|             return ret;
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|         }
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|     } else { /* DECRYPT */
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|         ret = mbedtls_poly1305_update(&ctx->poly1305_ctx, input, len);
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|         if (ret != 0) {
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|             return ret;
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|         }
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| 
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|         ret = mbedtls_chacha20_update(&ctx->chacha20_ctx, len, input, output);
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|         if (ret != 0) {
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|             return ret;
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|         }
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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_chachapoly_finish(mbedtls_chachapoly_context *ctx,
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|                               unsigned char mac[16])
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char len_block[16];
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| 
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|     if (ctx->state == CHACHAPOLY_STATE_INIT) {
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|         return MBEDTLS_ERR_CHACHAPOLY_BAD_STATE;
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|     }
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| 
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|     if (ctx->state == CHACHAPOLY_STATE_AAD) {
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|         ret = chachapoly_pad_aad(ctx);
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|         if (ret != 0) {
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|             return ret;
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|         }
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|     } else if (ctx->state == CHACHAPOLY_STATE_CIPHERTEXT) {
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|         ret = chachapoly_pad_ciphertext(ctx);
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|         if (ret != 0) {
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|             return ret;
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|         }
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|     }
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| 
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|     ctx->state = CHACHAPOLY_STATE_FINISHED;
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| 
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|     /* The lengths of the AAD and ciphertext are processed by
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|      * Poly1305 as the final 128-bit block, encoded as little-endian integers.
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|      */
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|     MBEDTLS_PUT_UINT64_LE(ctx->aad_len, len_block, 0);
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|     MBEDTLS_PUT_UINT64_LE(ctx->ciphertext_len, len_block, 8);
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| 
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|     ret = mbedtls_poly1305_update(&ctx->poly1305_ctx, len_block, 16U);
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|     if (ret != 0) {
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|         return ret;
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|     }
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| 
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|     ret = mbedtls_poly1305_finish(&ctx->poly1305_ctx, mac);
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| 
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|     return ret;
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| }
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| 
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| static int chachapoly_crypt_and_tag(mbedtls_chachapoly_context *ctx,
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|                                     mbedtls_chachapoly_mode_t mode,
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|                                     size_t length,
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|                                     const unsigned char nonce[12],
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|                                     const unsigned char *aad,
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|                                     size_t aad_len,
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|                                     const unsigned char *input,
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|                                     unsigned char *output,
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|                                     unsigned char tag[16])
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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| 
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|     ret = mbedtls_chachapoly_starts(ctx, nonce, mode);
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|     if (ret != 0) {
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|         goto cleanup;
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|     }
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| 
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|     ret = mbedtls_chachapoly_update_aad(ctx, aad, aad_len);
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|     if (ret != 0) {
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|         goto cleanup;
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|     }
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| 
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|     ret = mbedtls_chachapoly_update(ctx, length, input, output);
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|     if (ret != 0) {
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|         goto cleanup;
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|     }
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| 
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|     ret = mbedtls_chachapoly_finish(ctx, tag);
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| 
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| cleanup:
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|     return ret;
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| }
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| 
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| int mbedtls_chachapoly_encrypt_and_tag(mbedtls_chachapoly_context *ctx,
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|                                        size_t length,
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|                                        const unsigned char nonce[12],
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|                                        const unsigned char *aad,
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|                                        size_t aad_len,
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|                                        const unsigned char *input,
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|                                        unsigned char *output,
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|                                        unsigned char tag[16])
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| {
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|     return chachapoly_crypt_and_tag(ctx, MBEDTLS_CHACHAPOLY_ENCRYPT,
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|                                     length, nonce, aad, aad_len,
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|                                     input, output, tag);
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| }
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| 
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| int mbedtls_chachapoly_auth_decrypt(mbedtls_chachapoly_context *ctx,
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|                                     size_t length,
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|                                     const unsigned char nonce[12],
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|                                     const unsigned char *aad,
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|                                     size_t aad_len,
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|                                     const unsigned char tag[16],
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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 check_tag[16];
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|     int diff;
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| 
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|     if ((ret = chachapoly_crypt_and_tag(ctx,
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|                                         MBEDTLS_CHACHAPOLY_DECRYPT, length, nonce,
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|                                         aad, aad_len, input, output, check_tag)) != 0) {
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|         return ret;
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|     }
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| 
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|     /* Check tag in "constant-time" */
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|     diff = mbedtls_ct_memcmp(tag, check_tag, sizeof(check_tag));
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| 
 | |
|     if (diff != 0) {
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|         mbedtls_platform_zeroize(output, length);
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|         return MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED;
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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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| #endif /* MBEDTLS_CHACHAPOLY_ALT */
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| 
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| #if defined(MBEDTLS_SELF_TEST)
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| 
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| static const unsigned char test_key[1][32] =
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| {
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|     {
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|         0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
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|         0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
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|         0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
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|         0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f
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|     }
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| };
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| 
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| static const unsigned char test_nonce[1][12] =
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| {
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|     {
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|         0x07, 0x00, 0x00, 0x00,                         /* 32-bit common part */
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|         0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47  /* 64-bit IV */
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|     }
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| };
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| 
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| static const unsigned char test_aad[1][12] =
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| {
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|     {
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|         0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3,
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|         0xc4, 0xc5, 0xc6, 0xc7
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|     }
 | |
| };
 | |
| 
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| static const size_t test_aad_len[1] =
 | |
| {
 | |
|     12U
 | |
| };
 | |
| 
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| static const unsigned char test_input[1][114] =
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| {
 | |
|     {
 | |
|         0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61,
 | |
|         0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c,
 | |
|         0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20,
 | |
|         0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73,
 | |
|         0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39,
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|         0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63,
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|         0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66,
 | |
|         0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f,
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|         0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20,
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|         0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20,
 | |
|         0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75,
 | |
|         0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73,
 | |
|         0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f,
 | |
|         0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69,
 | |
|         0x74, 0x2e
 | |
|     }
 | |
| };
 | |
| 
 | |
| static const unsigned char test_output[1][114] =
 | |
| {
 | |
|     {
 | |
|         0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb,
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|         0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2,
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|         0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x08, 0xfe,
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|         0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6,
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|         0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12,
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|         0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b,
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|         0x1a, 0x71, 0xde, 0x0a, 0x9e, 0x06, 0x0b, 0x29,
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|         0x05, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36,
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|         0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c,
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|         0x98, 0x03, 0xae, 0xe3, 0x28, 0x09, 0x1b, 0x58,
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|         0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94,
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|         0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc,
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|         0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d,
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|         0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b,
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|         0x61, 0x16
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|     }
 | |
| };
 | |
| 
 | |
| static const size_t test_input_len[1] =
 | |
| {
 | |
|     114U
 | |
| };
 | |
| 
 | |
| static const unsigned char test_mac[1][16] =
 | |
| {
 | |
|     {
 | |
|         0x1a, 0xe1, 0x0b, 0x59, 0x4f, 0x09, 0xe2, 0x6a,
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|         0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60, 0x06, 0x91
 | |
|     }
 | |
| };
 | |
| 
 | |
| /* Make sure no other definition is already present. */
 | |
| #undef ASSERT
 | |
| 
 | |
| #define ASSERT(cond, args)            \
 | |
|     do                                  \
 | |
|     {                                   \
 | |
|         if (!(cond))                \
 | |
|         {                               \
 | |
|             if (verbose != 0)          \
 | |
|             mbedtls_printf args;    \
 | |
|                                         \
 | |
|             return -1;               \
 | |
|         }                               \
 | |
|     }                                   \
 | |
|     while (0)
 | |
| 
 | |
| int mbedtls_chachapoly_self_test(int verbose)
 | |
| {
 | |
|     mbedtls_chachapoly_context ctx;
 | |
|     unsigned i;
 | |
|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 | |
|     unsigned char output[200];
 | |
|     unsigned char mac[16];
 | |
| 
 | |
|     for (i = 0U; i < 1U; i++) {
 | |
|         if (verbose != 0) {
 | |
|             mbedtls_printf("  ChaCha20-Poly1305 test %u ", i);
 | |
|         }
 | |
| 
 | |
|         mbedtls_chachapoly_init(&ctx);
 | |
| 
 | |
|         ret = mbedtls_chachapoly_setkey(&ctx, test_key[i]);
 | |
|         ASSERT(0 == ret, ("setkey() error code: %i\n", ret));
 | |
| 
 | |
|         ret = mbedtls_chachapoly_encrypt_and_tag(&ctx,
 | |
|                                                  test_input_len[i],
 | |
|                                                  test_nonce[i],
 | |
|                                                  test_aad[i],
 | |
|                                                  test_aad_len[i],
 | |
|                                                  test_input[i],
 | |
|                                                  output,
 | |
|                                                  mac);
 | |
| 
 | |
|         ASSERT(0 == ret, ("crypt_and_tag() error code: %i\n", ret));
 | |
| 
 | |
|         ASSERT(0 == memcmp(output, test_output[i], test_input_len[i]),
 | |
|                ("failure (wrong output)\n"));
 | |
| 
 | |
|         ASSERT(0 == memcmp(mac, test_mac[i], 16U),
 | |
|                ("failure (wrong MAC)\n"));
 | |
| 
 | |
|         mbedtls_chachapoly_free(&ctx);
 | |
| 
 | |
|         if (verbose != 0) {
 | |
|             mbedtls_printf("passed\n");
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if (verbose != 0) {
 | |
|         mbedtls_printf("\n");
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| #endif /* MBEDTLS_SELF_TEST */
 | |
| 
 | |
| #endif /* MBEDTLS_CHACHAPOLY_C */
 |