538 lines
16 KiB
C
538 lines
16 KiB
C
/**
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* \file poly1305.c
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*
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* \brief Poly1305 authentication algorithm.
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*
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* Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* This file is part of mbed TLS (https://tls.mbed.org)
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*/
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#if !defined(MBEDTLS_CONFIG_FILE)
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#include "mbedtls/config.h"
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#else
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#include MBEDTLS_CONFIG_FILE
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#endif
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#if defined(MBEDTLS_POLY1305_C)
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#if !defined(MBEDTLS_POLY1305_ALT)
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#include "mbedtls/poly1305.h"
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#include <string.h>
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#if defined(MBEDTLS_SELF_TEST)
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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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#include <stdio.h>
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#define mbedtls_printf printf
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#endif /* MBEDTLS_PLATFORM_C */
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#endif /* MBEDTLS_SELF_TEST */
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#define POLY1305_BLOCK_SIZE_BYTES ( 16U )
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#define BYTES_TO_U32_LE( data, offset ) \
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( (uint32_t) data[offset] \
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| (uint32_t) ( (uint32_t) data[( offset ) + 1] << 8 ) \
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| (uint32_t) ( (uint32_t) data[( offset ) + 2] << 16 ) \
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| (uint32_t) ( (uint32_t) data[( offset ) + 3] << 24 ) \
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)
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/* Implementation that should never be optimized out by the compiler */
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static void mbedtls_zeroize( void *v, size_t n ) {
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volatile unsigned char *p = v; while( n-- ) *p++ = 0;
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}
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/**
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* \brief Process blocks with Poly1305.
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*
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* \param ctx The Poly1305 context.
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* \param nblocks Number of blocks to process. Note that this function
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* only processes full blocks.
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* \param input Buffer containing the input block(s).
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* \param needs_padding Set to 0 if the padding bit has already been applied
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* to the input data before calling this function.
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* Otherwise, set this parameter to 1.
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*/
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static void mbedtls_poly1305_process( mbedtls_poly1305_context *ctx,
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size_t nblocks,
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const unsigned char *input,
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uint32_t needs_padding )
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{
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uint64_t d0, d1, d2, d3;
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uint32_t acc0, acc1, acc2, acc3, acc4;
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uint32_t r0, r1, r2, r3;
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uint32_t rs1, rs2, rs3;
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size_t offset = 0U;
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size_t i;
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r0 = ctx->r[0];
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r1 = ctx->r[1];
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r2 = ctx->r[2];
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r3 = ctx->r[3];
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rs1 = r1 + ( r1 >> 2U );
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rs2 = r2 + ( r2 >> 2U );
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rs3 = r3 + ( r3 >> 2U );
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acc0 = ctx->acc[0];
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acc1 = ctx->acc[1];
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acc2 = ctx->acc[2];
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acc3 = ctx->acc[3];
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acc4 = ctx->acc[4];
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/* Process full blocks */
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for ( i = 0U; i < nblocks; i++ )
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{
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/* Compute: acc += block */
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/* Note that the input block is treated as a 128-bit little-endian integer */
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d0 = (uint64_t) acc0 + BYTES_TO_U32_LE( input, offset + 0 );
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d1 = (uint64_t) acc1 + BYTES_TO_U32_LE( input, offset + 4 ) + ( d0 >> 32U );
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d2 = (uint64_t) acc2 + BYTES_TO_U32_LE( input, offset + 8 ) + ( d1 >> 32U );
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d3 = (uint64_t) acc3 + BYTES_TO_U32_LE( input, offset + 12 ) + ( d2 >> 32U );
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acc0 = (uint32_t) d0;
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acc1 = (uint32_t) d1;
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acc2 = (uint32_t) d2;
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acc3 = (uint32_t) d3;
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acc4 += (uint32_t) ( d3 >> 32U ) + needs_padding;
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/* Compute: acc *= r */
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d0 = ( (uint64_t) acc0 * r0 ) +
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( (uint64_t) acc1 * rs3 ) +
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( (uint64_t) acc2 * rs2 ) +
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( (uint64_t) acc3 * rs1 );
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d1 = ( (uint64_t) acc0 * r1 ) +
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( (uint64_t) acc1 * r0 ) +
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( (uint64_t) acc2 * rs3 ) +
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( (uint64_t) acc3 * rs2 ) +
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( (uint64_t) acc4 * rs1 );
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d2 = ( (uint64_t) acc0 * r2 ) +
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( (uint64_t) acc1 * r1 ) +
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( (uint64_t) acc2 * r0 ) +
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( (uint64_t) acc3 * rs3 ) +
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( (uint64_t) acc4 * rs2 );
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d3 = ( (uint64_t) acc0 * r3 ) +
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( (uint64_t) acc1 * r2 ) +
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( (uint64_t) acc2 * r1 ) +
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( (uint64_t) acc3 * r0 ) +
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( (uint64_t) acc4 * rs3 );
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acc4 *= r0;
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/* Compute: acc %= (2^130 - 5) (partial remainder) */
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d1 += ( d0 >> 32 );
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d2 += ( d1 >> 32 );
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d3 += ( d2 >> 32 );
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acc0 = (uint32_t) d0;
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acc1 = (uint32_t) d1;
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acc2 = (uint32_t) d2;
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acc3 = (uint32_t) d3;
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acc4 = (uint32_t) ( d3 >> 32 ) + acc4;
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d0 = (uint64_t) acc0 + ( acc4 >> 2 ) + ( acc4 & 0xFFFFFFFCU );
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acc4 &= 3U;
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acc0 = (uint32_t) d0;
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d0 = (uint64_t) acc1 + ( d0 >> 32U );
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acc1 = (uint32_t) d0;
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d0 = (uint64_t) acc2 + ( d0 >> 32U );
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acc2 = (uint32_t) d0;
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d0 = (uint64_t) acc3 + ( d0 >> 32U );
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acc3 = (uint32_t) d0;
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d0 = (uint64_t) acc4 + ( d0 >> 32U );
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acc4 = (uint32_t) d0;
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offset += POLY1305_BLOCK_SIZE_BYTES;
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}
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ctx->acc[0] = acc0;
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ctx->acc[1] = acc1;
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ctx->acc[2] = acc2;
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ctx->acc[3] = acc3;
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ctx->acc[4] = acc4;
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}
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/**
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* \brief Compute the Poly1305 MAC
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*
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* \param ctx The Poly1305 context.
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* \param mac The buffer to where the MAC is written. Must be
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* big enough to contain the 16-byte MAC.
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*/
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static void mbedtls_poly1305_compute_mac( const mbedtls_poly1305_context *ctx,
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unsigned char mac[16] )
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{
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uint64_t d;
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uint32_t g0, g1, g2, g3, g4;
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uint32_t acc0, acc1, acc2, acc3, acc4;
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uint32_t mask;
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uint32_t mask_inv;
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acc0 = ctx->acc[0];
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acc1 = ctx->acc[1];
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acc2 = ctx->acc[2];
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acc3 = ctx->acc[3];
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acc4 = ctx->acc[4];
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/* Before adding 's' we need to ensure that the accumulator is mod 2^130 - 5.
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* We do this by calculating acc - (2^130 - 5), then checking if
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* the 131st bit is set. If it is, then reduce: acc -= (2^130 - 5)
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*/
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/* Calculate acc + -(2^130 - 5) */
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d = ( (uint64_t) acc0 + 5U );
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g0 = (uint32_t) d;
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d = ( (uint64_t) acc1 + ( d >> 32 ) );
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g1 = (uint32_t) d;
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d = ( (uint64_t) acc2 + ( d >> 32 ) );
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g2 = (uint32_t) d;
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d = ( (uint64_t) acc3 + ( d >> 32 ) );
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g3 = (uint32_t) d;
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g4 = acc4 + (uint32_t) ( d >> 32U );
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/* mask == 0xFFFFFFFF if 131st bit is set, otherwise mask == 0 */
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mask = (uint32_t) 0U - ( g4 >> 2U );
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mask_inv = ~mask;
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/* If 131st bit is set then acc=g, otherwise, acc is unmodified */
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acc0 = ( acc0 & mask_inv ) | ( g0 & mask );
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acc1 = ( acc1 & mask_inv ) | ( g1 & mask );
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acc2 = ( acc2 & mask_inv ) | ( g2 & mask );
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acc3 = ( acc3 & mask_inv ) | ( g3 & mask );
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/* Add 's' */
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d = (uint64_t) acc0 + ctx->s[0];
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acc0 = (uint32_t) d;
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d = (uint64_t) acc1 + ctx->s[1] + ( d >> 32U );
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acc1 = (uint32_t) d;
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d = (uint64_t) acc2 + ctx->s[2] + ( d >> 32U );
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acc2 = (uint32_t) d;
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acc3 += ctx->s[3] + (uint32_t) ( d >> 32U );
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/* Compute MAC (128 least significant bits of the accumulator) */
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mac[0] = (unsigned char) acc0;
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mac[1] = (unsigned char) ( acc0 >> 8 );
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mac[2] = (unsigned char) ( acc0 >> 16 );
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mac[3] = (unsigned char) ( acc0 >> 24 );
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mac[4] = (unsigned char) acc1;
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mac[5] = (unsigned char) ( acc1 >> 8 );
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mac[6] = (unsigned char) ( acc1 >> 16 );
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mac[7] = (unsigned char) ( acc1 >> 24 );
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mac[8] = (unsigned char) acc2;
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mac[9] = (unsigned char) ( acc2 >> 8 );
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mac[10] = (unsigned char) ( acc2 >> 16 );
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mac[11] = (unsigned char) ( acc2 >> 24 );
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mac[12] = (unsigned char) acc3;
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mac[13] = (unsigned char) ( acc3 >> 8 );
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mac[14] = (unsigned char) ( acc3 >> 16 );
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mac[15] = (unsigned char) ( acc3 >> 24 );
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}
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void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx )
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{
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if ( ctx != NULL )
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{
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mbedtls_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
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}
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}
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void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx )
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{
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if ( ctx != NULL )
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{
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mbedtls_zeroize( ctx, sizeof( mbedtls_poly1305_context ) );
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}
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}
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int mbedtls_poly1305_setkey( mbedtls_poly1305_context *ctx,
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const unsigned char key[32] )
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{
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if ( ctx == NULL )
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{
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return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
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}
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/* r &= 0x0ffffffc0ffffffc0ffffffc0fffffff */
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ctx->r[0] = BYTES_TO_U32_LE( key, 0 ) & 0x0FFFFFFFU;
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ctx->r[1] = BYTES_TO_U32_LE( key, 4 ) & 0x0FFFFFFCU;
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ctx->r[2] = BYTES_TO_U32_LE( key, 8 ) & 0x0FFFFFFCU;
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ctx->r[3] = BYTES_TO_U32_LE( key, 12 ) & 0x0FFFFFFCU;
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ctx->s[0] = BYTES_TO_U32_LE( key, 16 );
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ctx->s[1] = BYTES_TO_U32_LE( key, 20 );
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ctx->s[2] = BYTES_TO_U32_LE( key, 24 );
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ctx->s[3] = BYTES_TO_U32_LE( key, 28 );
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/* Initial accumulator state */
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ctx->acc[0] = 0U;
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ctx->acc[1] = 0U;
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ctx->acc[2] = 0U;
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ctx->acc[3] = 0U;
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return( 0 );
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}
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int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx,
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size_t ilen,
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const unsigned char* input )
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{
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size_t offset = 0U;
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size_t remaining = ilen;
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size_t queue_free_len;
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size_t nblocks;
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if ( ctx == NULL )
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{
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return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
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}
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else if ( ( ilen > 0U ) && ( input == NULL ) )
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{
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/* input pointer is allowed to be NULL only if ilen == 0 */
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return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
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}
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if ( ( remaining > 0U ) && ( ctx->queue_len > 0U ) )
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{
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queue_free_len = ( POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len );
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if ( ilen < queue_free_len )
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{
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/* Not enough data to complete the block.
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* Store this data with the other leftovers.
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*/
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memcpy( &ctx->queue[ctx->queue_len],
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input,
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ilen );
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ctx->queue_len += ilen;
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remaining = 0U;
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}
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else
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{
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/* Enough data to produce a complete block */
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memcpy( &ctx->queue[ctx->queue_len],
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input,
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queue_free_len );
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ctx->queue_len = 0U;
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mbedtls_poly1305_process( ctx,
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1U,
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ctx->queue,
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1U ); /* add padding bit */
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offset += queue_free_len;
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remaining -= queue_free_len;
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}
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}
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if ( remaining >= POLY1305_BLOCK_SIZE_BYTES )
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{
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nblocks = remaining / POLY1305_BLOCK_SIZE_BYTES;
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mbedtls_poly1305_process( ctx, nblocks, &input[offset], 1U );
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offset += nblocks * POLY1305_BLOCK_SIZE_BYTES;
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remaining %= POLY1305_BLOCK_SIZE_BYTES;
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}
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if ( remaining > 0U )
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{
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/* Store partial block */
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ctx->queue_len = remaining;
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memcpy( ctx->queue, &input[offset], remaining );
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}
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return( 0 );
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}
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int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx,
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unsigned char mac[16] )
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{
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if ( ( ctx == NULL ) || ( mac == NULL ) )
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{
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return( MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA );
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}
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/* Process any leftover data */
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if ( ctx->queue_len > 0U )
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{
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/* Add padding bit */
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ctx->queue[ctx->queue_len] = 1U;
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ctx->queue_len++;
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/* Pad with zeroes */
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memset( &ctx->queue[ctx->queue_len],
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0,
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POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len );
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mbedtls_poly1305_process( ctx,
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1U, /* Process 1 block */
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ctx->queue,
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0U ); /* Don't add padding bit (it was just added above) */
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}
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mbedtls_poly1305_compute_mac( ctx, mac );
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return( 0 );
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}
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#endif /* MBEDTLS_POLY1305_ALT */
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int mbedtls_poly1305_mac( const unsigned char key[32],
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size_t ilen,
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const unsigned char *input,
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unsigned char mac[16] )
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{
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mbedtls_poly1305_context ctx;
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int result;
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mbedtls_poly1305_init( &ctx );
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result = mbedtls_poly1305_setkey( &ctx, key );
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if ( result != 0 )
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goto cleanup;
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result = mbedtls_poly1305_update( &ctx, ilen, input );
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if ( result != 0 )
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goto cleanup;
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result = mbedtls_poly1305_finish( &ctx, mac );
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cleanup:
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mbedtls_poly1305_free( &ctx );
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return( 0 );
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}
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#if defined(MBEDTLS_SELF_TEST)
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static const unsigned char test_keys[2][32] =
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{
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{
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0x85, 0xd6, 0xbe, 0x78, 0x57, 0x55, 0x6d, 0x33,
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0x7f, 0x44, 0x52, 0xfe, 0x42, 0xd5, 0x06, 0xa8,
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0x01, 0x03, 0x80, 0x8a, 0xfb, 0x0d, 0xb2, 0xfd,
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0x4a, 0xbf, 0xf6, 0xaf, 0x41, 0x49, 0xf5, 0x1b
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},
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{
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0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a,
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0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0,
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0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09,
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0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0
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}
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};
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static const unsigned char test_data[2][127] =
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{
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{
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0x43, 0x72, 0x79, 0x70, 0x74, 0x6f, 0x67, 0x72,
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0x61, 0x70, 0x68, 0x69, 0x63, 0x20, 0x46, 0x6f,
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0x72, 0x75, 0x6d, 0x20, 0x52, 0x65, 0x73, 0x65,
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0x61, 0x72, 0x63, 0x68, 0x20, 0x47, 0x72, 0x6f,
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0x75, 0x70
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},
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{
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0x27, 0x54, 0x77, 0x61, 0x73, 0x20, 0x62, 0x72,
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0x69, 0x6c, 0x6c, 0x69, 0x67, 0x2c, 0x20, 0x61,
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0x6e, 0x64, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73,
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0x6c, 0x69, 0x74, 0x68, 0x79, 0x20, 0x74, 0x6f,
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0x76, 0x65, 0x73, 0x0a, 0x44, 0x69, 0x64, 0x20,
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0x67, 0x79, 0x72, 0x65, 0x20, 0x61, 0x6e, 0x64,
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0x20, 0x67, 0x69, 0x6d, 0x62, 0x6c, 0x65, 0x20,
|
|
0x69, 0x6e, 0x20, 0x74, 0x68, 0x65, 0x20, 0x77,
|
|
0x61, 0x62, 0x65, 0x3a, 0x0a, 0x41, 0x6c, 0x6c,
|
|
0x20, 0x6d, 0x69, 0x6d, 0x73, 0x79, 0x20, 0x77,
|
|
0x65, 0x72, 0x65, 0x20, 0x74, 0x68, 0x65, 0x20,
|
|
0x62, 0x6f, 0x72, 0x6f, 0x67, 0x6f, 0x76, 0x65,
|
|
0x73, 0x2c, 0x0a, 0x41, 0x6e, 0x64, 0x20, 0x74,
|
|
0x68, 0x65, 0x20, 0x6d, 0x6f, 0x6d, 0x65, 0x20,
|
|
0x72, 0x61, 0x74, 0x68, 0x73, 0x20, 0x6f, 0x75,
|
|
0x74, 0x67, 0x72, 0x61, 0x62, 0x65, 0x2e
|
|
}
|
|
};
|
|
|
|
static const size_t test_data_len[2] =
|
|
{
|
|
34U,
|
|
127U
|
|
};
|
|
|
|
static const unsigned char test_mac[2][16] =
|
|
{
|
|
{
|
|
0xa8, 0x06, 0x1d, 0xc1, 0x30, 0x51, 0x36, 0xc6,
|
|
0xc2, 0x2b, 0x8b, 0xaf, 0x0c, 0x01, 0x27, 0xa9
|
|
},
|
|
{
|
|
0x45, 0x41, 0x66, 0x9a, 0x7e, 0xaa, 0xee, 0x61,
|
|
0xe7, 0x08, 0xdc, 0x7c, 0xbc, 0xc5, 0xeb, 0x62
|
|
}
|
|
};
|
|
|
|
int mbedtls_poly1305_self_test( int verbose )
|
|
{
|
|
unsigned char mac[16];
|
|
size_t i;
|
|
int result;
|
|
|
|
for ( i = 0U; i < 2U; i++ )
|
|
{
|
|
if ( verbose != 0 )
|
|
{
|
|
mbedtls_printf( " Poly1305 test %zu ", i );
|
|
}
|
|
|
|
result = mbedtls_poly1305_mac( test_keys[i],
|
|
test_data_len[i],
|
|
test_data[i],
|
|
mac );
|
|
if ( result != 0 )
|
|
{
|
|
if ( verbose != 0 )
|
|
{
|
|
mbedtls_printf( "error code: %i\n", result );
|
|
}
|
|
|
|
return( -1 );
|
|
}
|
|
|
|
if ( memcmp( mac, test_mac[i], 16U ) != 0 )
|
|
{
|
|
if ( verbose != 0 )
|
|
{
|
|
mbedtls_printf( "failed\n" );
|
|
}
|
|
|
|
return( -1 );
|
|
}
|
|
|
|
if ( verbose != 0 )
|
|
{
|
|
mbedtls_printf( "passed\n" );
|
|
}
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
{
|
|
mbedtls_printf( "\n" );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_POLY1305_C */
|