/** | |
* \file poly1305.c | |
* | |
* \brief Poly1305 authentication algorithm. | |
* | |
* Copyright (C) 2006-2016, ARM Limited, All Rights Reserved | |
* SPDX-License-Identifier: Apache-2.0 | |
* | |
* Licensed under the Apache License, Version 2.0 (the "License"); you may | |
* not use this file except in compliance with the License. | |
* You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT | |
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
* | |
* This file is part of mbed TLS (https://tls.mbed.org) | |
*/ | |
#if !defined(MBEDTLS_CONFIG_FILE) | |
#include "mbedtls/config.h" | |
#else | |
#include MBEDTLS_CONFIG_FILE | |
#endif | |
#if defined(MBEDTLS_POLY1305_C) | |
#include "mbedtls/poly1305.h" | |
#include "mbedtls/platform_util.h" | |
#include <string.h> | |
#if defined(MBEDTLS_SELF_TEST) | |
#if defined(MBEDTLS_PLATFORM_C) | |
#include "mbedtls/platform.h" | |
#else | |
#include <stdio.h> | |
#define mbedtls_printf printf | |
#endif /* MBEDTLS_PLATFORM_C */ | |
#endif /* MBEDTLS_SELF_TEST */ | |
#if !defined(MBEDTLS_POLY1305_ALT) | |
#if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \ | |
!defined(inline) && !defined(__cplusplus) | |
#define inline __inline | |
#endif | |
/* Parameter validation macros */ | |
#define POLY1305_VALIDATE_RET( cond ) \ | |
MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA ) | |
#define POLY1305_VALIDATE( cond ) \ | |
MBEDTLS_INTERNAL_VALIDATE( cond ) | |
#define POLY1305_BLOCK_SIZE_BYTES ( 16U ) | |
#define BYTES_TO_U32_LE( data, offset ) \ | |
( (uint32_t) (data)[offset] \ | |
| (uint32_t) ( (uint32_t) (data)[( offset ) + 1] << 8 ) \ | |
| (uint32_t) ( (uint32_t) (data)[( offset ) + 2] << 16 ) \ | |
| (uint32_t) ( (uint32_t) (data)[( offset ) + 3] << 24 ) \ | |
) | |
/* | |
* Our implementation is tuned for 32-bit platforms with a 64-bit multiplier. | |
* However we provided an alternative for platforms without such a multiplier. | |
*/ | |
#if defined(MBEDTLS_NO_64BIT_MULTIPLICATION) | |
static uint64_t mul64( uint32_t a, uint32_t b ) | |
{ | |
/* a = al + 2**16 ah, b = bl + 2**16 bh */ | |
const uint16_t al = (uint16_t) a; | |
const uint16_t bl = (uint16_t) b; | |
const uint16_t ah = a >> 16; | |
const uint16_t bh = b >> 16; | |
/* ab = al*bl + 2**16 (ah*bl + bl*bh) + 2**32 ah*bh */ | |
const uint32_t lo = (uint32_t) al * bl; | |
const uint64_t me = (uint64_t)( (uint32_t) ah * bl ) + (uint32_t) al * bh; | |
const uint32_t hi = (uint32_t) ah * bh; | |
return( lo + ( me << 16 ) + ( (uint64_t) hi << 32 ) ); | |
} | |
#else | |
static inline uint64_t mul64( uint32_t a, uint32_t b ) | |
{ | |
return( (uint64_t) a * b ); | |
} | |
#endif | |
/** | |
* \brief Process blocks with Poly1305. | |
* | |
* \param ctx The Poly1305 context. | |
* \param nblocks Number of blocks to process. Note that this | |
* function only processes full blocks. | |
* \param input Buffer containing the input block(s). | |
* \param needs_padding Set to 0 if the padding bit has already been | |
* applied to the input data before calling this | |
* function. Otherwise, set this parameter to 1. | |
*/ | |
static void poly1305_process( mbedtls_poly1305_context *ctx, | |
size_t nblocks, | |
const unsigned char *input, | |
uint32_t needs_padding ) | |
{ | |
uint64_t d0, d1, d2, d3; | |
uint32_t acc0, acc1, acc2, acc3, acc4; | |
uint32_t r0, r1, r2, r3; | |
uint32_t rs1, rs2, rs3; | |
size_t offset = 0U; | |
size_t i; | |
r0 = ctx->r[0]; | |
r1 = ctx->r[1]; | |
r2 = ctx->r[2]; | |
r3 = ctx->r[3]; | |
rs1 = r1 + ( r1 >> 2U ); | |
rs2 = r2 + ( r2 >> 2U ); | |
rs3 = r3 + ( r3 >> 2U ); | |
acc0 = ctx->acc[0]; | |
acc1 = ctx->acc[1]; | |
acc2 = ctx->acc[2]; | |
acc3 = ctx->acc[3]; | |
acc4 = ctx->acc[4]; | |
/* Process full blocks */ | |
for( i = 0U; i < nblocks; i++ ) | |
{ | |
/* The input block is treated as a 128-bit little-endian integer */ | |
d0 = BYTES_TO_U32_LE( input, offset + 0 ); | |
d1 = BYTES_TO_U32_LE( input, offset + 4 ); | |
d2 = BYTES_TO_U32_LE( input, offset + 8 ); | |
d3 = BYTES_TO_U32_LE( input, offset + 12 ); | |
/* Compute: acc += (padded) block as a 130-bit integer */ | |
d0 += (uint64_t) acc0; | |
d1 += (uint64_t) acc1 + ( d0 >> 32U ); | |
d2 += (uint64_t) acc2 + ( d1 >> 32U ); | |
d3 += (uint64_t) acc3 + ( d2 >> 32U ); | |
acc0 = (uint32_t) d0; | |
acc1 = (uint32_t) d1; | |
acc2 = (uint32_t) d2; | |
acc3 = (uint32_t) d3; | |
acc4 += (uint32_t) ( d3 >> 32U ) + needs_padding; | |
/* Compute: acc *= r */ | |
d0 = mul64( acc0, r0 ) + | |
mul64( acc1, rs3 ) + | |
mul64( acc2, rs2 ) + | |
mul64( acc3, rs1 ); | |
d1 = mul64( acc0, r1 ) + | |
mul64( acc1, r0 ) + | |
mul64( acc2, rs3 ) + | |
mul64( acc3, rs2 ) + | |
mul64( acc4, rs1 ); | |
d2 = mul64( acc0, r2 ) + | |
mul64( acc1, r1 ) + | |
mul64( acc2, r0 ) + | |
mul64( acc3, rs3 ) + | |
mul64( acc4, rs2 ); | |
d3 = mul64( acc0, r3 ) + | |
mul64( acc1, r2 ) + | |
mul64( acc2, r1 ) + | |
mul64( acc3, r0 ) + | |
mul64( acc4, rs3 ); | |
acc4 *= r0; | |
/* Compute: acc %= (2^130 - 5) (partial remainder) */ | |
d1 += ( d0 >> 32 ); | |
d2 += ( d1 >> 32 ); | |
d3 += ( d2 >> 32 ); | |
acc0 = (uint32_t) d0; | |
acc1 = (uint32_t) d1; | |
acc2 = (uint32_t) d2; | |
acc3 = (uint32_t) d3; | |
acc4 = (uint32_t) ( d3 >> 32 ) + acc4; | |
d0 = (uint64_t) acc0 + ( acc4 >> 2 ) + ( acc4 & 0xFFFFFFFCU ); | |
acc4 &= 3U; | |
acc0 = (uint32_t) d0; | |
d0 = (uint64_t) acc1 + ( d0 >> 32U ); | |
acc1 = (uint32_t) d0; | |
d0 = (uint64_t) acc2 + ( d0 >> 32U ); | |
acc2 = (uint32_t) d0; | |
d0 = (uint64_t) acc3 + ( d0 >> 32U ); | |
acc3 = (uint32_t) d0; | |
d0 = (uint64_t) acc4 + ( d0 >> 32U ); | |
acc4 = (uint32_t) d0; | |
offset += POLY1305_BLOCK_SIZE_BYTES; | |
} | |
ctx->acc[0] = acc0; | |
ctx->acc[1] = acc1; | |
ctx->acc[2] = acc2; | |
ctx->acc[3] = acc3; | |
ctx->acc[4] = acc4; | |
} | |
/** | |
* \brief Compute the Poly1305 MAC | |
* | |
* \param ctx The Poly1305 context. | |
* \param mac The buffer to where the MAC is written. Must be | |
* big enough to contain the 16-byte MAC. | |
*/ | |
static void poly1305_compute_mac( const mbedtls_poly1305_context *ctx, | |
unsigned char mac[16] ) | |
{ | |
uint64_t d; | |
uint32_t g0, g1, g2, g3, g4; | |
uint32_t acc0, acc1, acc2, acc3, acc4; | |
uint32_t mask; | |
uint32_t mask_inv; | |
acc0 = ctx->acc[0]; | |
acc1 = ctx->acc[1]; | |
acc2 = ctx->acc[2]; | |
acc3 = ctx->acc[3]; | |
acc4 = ctx->acc[4]; | |
/* Before adding 's' we ensure that the accumulator is mod 2^130 - 5. | |
* We do this by calculating acc - (2^130 - 5), then checking if | |
* the 131st bit is set. If it is, then reduce: acc -= (2^130 - 5) | |
*/ | |
/* Calculate acc + -(2^130 - 5) */ | |
d = ( (uint64_t) acc0 + 5U ); | |
g0 = (uint32_t) d; | |
d = ( (uint64_t) acc1 + ( d >> 32 ) ); | |
g1 = (uint32_t) d; | |
d = ( (uint64_t) acc2 + ( d >> 32 ) ); | |
g2 = (uint32_t) d; | |
d = ( (uint64_t) acc3 + ( d >> 32 ) ); | |
g3 = (uint32_t) d; | |
g4 = acc4 + (uint32_t) ( d >> 32U ); | |
/* mask == 0xFFFFFFFF if 131st bit is set, otherwise mask == 0 */ | |
mask = (uint32_t) 0U - ( g4 >> 2U ); | |
mask_inv = ~mask; | |
/* If 131st bit is set then acc=g, otherwise, acc is unmodified */ | |
acc0 = ( acc0 & mask_inv ) | ( g0 & mask ); | |
acc1 = ( acc1 & mask_inv ) | ( g1 & mask ); | |
acc2 = ( acc2 & mask_inv ) | ( g2 & mask ); | |
acc3 = ( acc3 & mask_inv ) | ( g3 & mask ); | |
/* Add 's' */ | |
d = (uint64_t) acc0 + ctx->s[0]; | |
acc0 = (uint32_t) d; | |
d = (uint64_t) acc1 + ctx->s[1] + ( d >> 32U ); | |
acc1 = (uint32_t) d; | |
d = (uint64_t) acc2 + ctx->s[2] + ( d >> 32U ); | |
acc2 = (uint32_t) d; | |
acc3 += ctx->s[3] + (uint32_t) ( d >> 32U ); | |
/* Compute MAC (128 least significant bits of the accumulator) */ | |
mac[ 0] = (unsigned char)( acc0 ); | |
mac[ 1] = (unsigned char)( acc0 >> 8 ); | |
mac[ 2] = (unsigned char)( acc0 >> 16 ); | |
mac[ 3] = (unsigned char)( acc0 >> 24 ); | |
mac[ 4] = (unsigned char)( acc1 ); | |
mac[ 5] = (unsigned char)( acc1 >> 8 ); | |
mac[ 6] = (unsigned char)( acc1 >> 16 ); | |
mac[ 7] = (unsigned char)( acc1 >> 24 ); | |
mac[ 8] = (unsigned char)( acc2 ); | |
mac[ 9] = (unsigned char)( acc2 >> 8 ); | |
mac[10] = (unsigned char)( acc2 >> 16 ); | |
mac[11] = (unsigned char)( acc2 >> 24 ); | |
mac[12] = (unsigned char)( acc3 ); | |
mac[13] = (unsigned char)( acc3 >> 8 ); | |
mac[14] = (unsigned char)( acc3 >> 16 ); | |
mac[15] = (unsigned char)( acc3 >> 24 ); | |
} | |
void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx ) | |
{ | |
POLY1305_VALIDATE( ctx != NULL ); | |
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) ); | |
} | |
void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx ) | |
{ | |
if( ctx == NULL ) | |
return; | |
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_poly1305_context ) ); | |
} | |
int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx, | |
const unsigned char key[32] ) | |
{ | |
POLY1305_VALIDATE_RET( ctx != NULL ); | |
POLY1305_VALIDATE_RET( key != NULL ); | |
/* r &= 0x0ffffffc0ffffffc0ffffffc0fffffff */ | |
ctx->r[0] = BYTES_TO_U32_LE( key, 0 ) & 0x0FFFFFFFU; | |
ctx->r[1] = BYTES_TO_U32_LE( key, 4 ) & 0x0FFFFFFCU; | |
ctx->r[2] = BYTES_TO_U32_LE( key, 8 ) & 0x0FFFFFFCU; | |
ctx->r[3] = BYTES_TO_U32_LE( key, 12 ) & 0x0FFFFFFCU; | |
ctx->s[0] = BYTES_TO_U32_LE( key, 16 ); | |
ctx->s[1] = BYTES_TO_U32_LE( key, 20 ); | |
ctx->s[2] = BYTES_TO_U32_LE( key, 24 ); | |
ctx->s[3] = BYTES_TO_U32_LE( key, 28 ); | |
/* Initial accumulator state */ | |
ctx->acc[0] = 0U; | |
ctx->acc[1] = 0U; | |
ctx->acc[2] = 0U; | |
ctx->acc[3] = 0U; | |
ctx->acc[4] = 0U; | |
/* Queue initially empty */ | |
mbedtls_platform_zeroize( ctx->queue, sizeof( ctx->queue ) ); | |
ctx->queue_len = 0U; | |
return( 0 ); | |
} | |
int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx, | |
const unsigned char *input, | |
size_t ilen ) | |
{ | |
size_t offset = 0U; | |
size_t remaining = ilen; | |
size_t queue_free_len; | |
size_t nblocks; | |
POLY1305_VALIDATE_RET( ctx != NULL ); | |
POLY1305_VALIDATE_RET( ilen == 0 || input != NULL ); | |
if( ( remaining > 0U ) && ( ctx->queue_len > 0U ) ) | |
{ | |
queue_free_len = ( POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len ); | |
if( ilen < queue_free_len ) | |
{ | |
/* Not enough data to complete the block. | |
* Store this data with the other leftovers. | |
*/ | |
memcpy( &ctx->queue[ctx->queue_len], | |
input, | |
ilen ); | |
ctx->queue_len += ilen; | |
remaining = 0U; | |
} | |
else | |
{ | |
/* Enough data to produce a complete block */ | |
memcpy( &ctx->queue[ctx->queue_len], | |
input, | |
queue_free_len ); | |
ctx->queue_len = 0U; | |
poly1305_process( ctx, 1U, ctx->queue, 1U ); /* add padding bit */ | |
offset += queue_free_len; | |
remaining -= queue_free_len; | |
} | |
} | |
if( remaining >= POLY1305_BLOCK_SIZE_BYTES ) | |
{ | |
nblocks = remaining / POLY1305_BLOCK_SIZE_BYTES; | |
poly1305_process( ctx, nblocks, &input[offset], 1U ); | |
offset += nblocks * POLY1305_BLOCK_SIZE_BYTES; | |
remaining %= POLY1305_BLOCK_SIZE_BYTES; | |
} | |
if( remaining > 0U ) | |
{ | |
/* Store partial block */ | |
ctx->queue_len = remaining; | |
memcpy( ctx->queue, &input[offset], remaining ); | |
} | |
return( 0 ); | |
} | |
int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx, | |
unsigned char mac[16] ) | |
{ | |
POLY1305_VALIDATE_RET( ctx != NULL ); | |
POLY1305_VALIDATE_RET( mac != NULL ); | |
/* Process any leftover data */ | |
if( ctx->queue_len > 0U ) | |
{ | |
/* Add padding bit */ | |
ctx->queue[ctx->queue_len] = 1U; | |
ctx->queue_len++; | |
/* Pad with zeroes */ | |
memset( &ctx->queue[ctx->queue_len], | |
0, | |
POLY1305_BLOCK_SIZE_BYTES - ctx->queue_len ); | |
poly1305_process( ctx, 1U, /* Process 1 block */ | |
ctx->queue, 0U ); /* Already padded above */ | |
} | |
poly1305_compute_mac( ctx, mac ); | |
return( 0 ); | |
} | |
int mbedtls_poly1305_mac( const unsigned char key[32], | |
const unsigned char *input, | |
size_t ilen, | |
unsigned char mac[16] ) | |
{ | |
mbedtls_poly1305_context ctx; | |
int ret; | |
POLY1305_VALIDATE_RET( key != NULL ); | |
POLY1305_VALIDATE_RET( mac != NULL ); | |
POLY1305_VALIDATE_RET( ilen == 0 || input != NULL ); | |
mbedtls_poly1305_init( &ctx ); | |
ret = mbedtls_poly1305_starts( &ctx, key ); | |
if( ret != 0 ) | |
goto cleanup; | |
ret = mbedtls_poly1305_update( &ctx, input, ilen ); | |
if( ret != 0 ) | |
goto cleanup; | |
ret = mbedtls_poly1305_finish( &ctx, mac ); | |
cleanup: | |
mbedtls_poly1305_free( &ctx ); | |
return( ret ); | |
} | |
#endif /* MBEDTLS_POLY1305_ALT */ | |
#if defined(MBEDTLS_SELF_TEST) | |
static const unsigned char test_keys[2][32] = | |
{ | |
{ | |
0x85, 0xd6, 0xbe, 0x78, 0x57, 0x55, 0x6d, 0x33, | |
0x7f, 0x44, 0x52, 0xfe, 0x42, 0xd5, 0x06, 0xa8, | |
0x01, 0x03, 0x80, 0x8a, 0xfb, 0x0d, 0xb2, 0xfd, | |
0x4a, 0xbf, 0xf6, 0xaf, 0x41, 0x49, 0xf5, 0x1b | |
}, | |
{ | |
0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, | |
0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0, | |
0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, | |
0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0 | |
} | |
}; | |
static const unsigned char test_data[2][127] = | |
{ | |
{ | |
0x43, 0x72, 0x79, 0x70, 0x74, 0x6f, 0x67, 0x72, | |
0x61, 0x70, 0x68, 0x69, 0x63, 0x20, 0x46, 0x6f, | |
0x72, 0x75, 0x6d, 0x20, 0x52, 0x65, 0x73, 0x65, | |
0x61, 0x72, 0x63, 0x68, 0x20, 0x47, 0x72, 0x6f, | |
0x75, 0x70 | |
}, | |
{ | |
0x27, 0x54, 0x77, 0x61, 0x73, 0x20, 0x62, 0x72, | |
0x69, 0x6c, 0x6c, 0x69, 0x67, 0x2c, 0x20, 0x61, | |
0x6e, 0x64, 0x20, 0x74, 0x68, 0x65, 0x20, 0x73, | |
0x6c, 0x69, 0x74, 0x68, 0x79, 0x20, 0x74, 0x6f, | |
0x76, 0x65, 0x73, 0x0a, 0x44, 0x69, 0x64, 0x20, | |
0x67, 0x79, 0x72, 0x65, 0x20, 0x61, 0x6e, 0x64, | |
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 | |
} | |
}; | |
#define ASSERT( cond, args ) \ | |
do \ | |
{ \ | |
if( ! ( cond ) ) \ | |
{ \ | |
if( verbose != 0 ) \ | |
mbedtls_printf args; \ | |
\ | |
return( -1 ); \ | |
} \ | |
} \ | |
while( 0 ) | |
int mbedtls_poly1305_self_test( int verbose ) | |
{ | |
unsigned char mac[16]; | |
unsigned i; | |
int ret; | |
for( i = 0U; i < 2U; i++ ) | |
{ | |
if( verbose != 0 ) | |
mbedtls_printf( " Poly1305 test %u ", i ); | |
ret = mbedtls_poly1305_mac( test_keys[i], | |
test_data[i], | |
test_data_len[i], | |
mac ); | |
ASSERT( 0 == ret, ( "error code: %i\n", ret ) ); | |
ASSERT( 0 == memcmp( mac, test_mac[i], 16U ), ( "failed (mac)\n" ) ); | |
if( verbose != 0 ) | |
mbedtls_printf( "passed\n" ); | |
} | |
if( verbose != 0 ) | |
mbedtls_printf( "\n" ); | |
return( 0 ); | |
} | |
#endif /* MBEDTLS_SELF_TEST */ | |
#endif /* MBEDTLS_POLY1305_C */ |