yuzu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2025-01-21 21:21:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #3841 from AndrzejKurek/baremetal-rnd-in-range-fix

Browse source 
Move size checks outside of mbedtls_platform_random_in_range
This commit is contained in:
Andrzej Kurek 2020-11-25 11:41:40 +01:00 committed by GitHub
parent 21f64d3633 a138c0a0b0
commit 5eba1d82a2
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 51 additions and 56 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
include/mbedtls/platform_util.h
View file

@ -276,9 +276,9 @@ uint32_t mbedtls_platform_random_uint32( void );
* cryptographically secure RNG, but provide an RNG for utility
* functions.
*
* \note If the given range is [0, 0), 0 is returned.
*
* \param num Max-value for the generated random number, exclusive.
* Must be greater than zero, otherwise an undefined behavior
* will occur on "num % 0".
* The generated number will be on range [0, num).
*
* \return The generated random number.

103
library/platform_util.c
View file

@ -119,43 +119,45 @@ void *mbedtls_platform_zeroize( void *buf, size_t len )
void *mbedtls_platform_memset( void *ptr, int value, size_t num )
{
size_t i, start_offset;
size_t i, start_offset = 0;
volatile size_t flow_counter = 0;
volatile char *b = ptr;
char rnd_data;
start_offset = (size_t) mbedtls_platform_random_in_range( (uint32_t) num );
rnd_data = (char) mbedtls_platform_random_in_range( 256 );
/* Perform a memset operations with random data and start from a random
* location */
for( i = start_offset; i < num; ++i )
if( num > 0 )
{
b[i] = rnd_data;
flow_counter++;
}
start_offset = (size_t) mbedtls_platform_random_in_range( (uint32_t) num );
/* Start from a random location with target data */
for( i = start_offset; i < num; ++i )
{
b[i] = value;
flow_counter++;
}
rnd_data = (char) mbedtls_platform_random_in_range( 256 );
/* Second memset operation with random data */
for( i = 0; i < start_offset; ++i )
{
b[i] = rnd_data;
flow_counter++;
}
/* Perform a memset operations with random data and start from a random
* location */
for( i = start_offset; i < num; ++i )
{
b[i] = rnd_data;
flow_counter++;
}
/* Finish memset operation with correct data */
for( i = 0; i < start_offset; ++i )
{
b[i] = value;
flow_counter++;
}
/* Start from a random location with target data */
for( i = start_offset; i < num; ++i )
{
b[i] = value;
flow_counter++;
}
/* Second memset operation with random data */
for( i = 0; i < start_offset; ++i )
{
b[i] = rnd_data;
flow_counter++;
}
/* Finish memset operation with correct data */
for( i = 0; i < start_offset; ++i )
{
b[i] = value;
flow_counter++;
}
}
/* check the correct number of iterations */
if( flow_counter == 2 * num )
{
@ -165,6 +167,7 @@ void *mbedtls_platform_memset( void *ptr, int value, size_t num )
return ptr;
}
}
return NULL;
}
@ -245,22 +248,25 @@ int mbedtls_platform_memequal( const void *buf1, const void *buf2, size_t num )
/* Start from a random location and check the correct number of iterations */
size_t i, flow_counter = 0;
size_t start_offset = (size_t) mbedtls_platform_random_in_range( (uint32_t) num );
for( i = start_offset; i < num; i++ )
size_t start_offset = 0;
if( num > 0 )
{
unsigned char x = A[i], y = B[i];
flow_counter++;
diff |= x ^ y;
}
start_offset = (size_t) mbedtls_platform_random_in_range( (uint32_t) num );
for( i = 0; i < start_offset; i++ )
{
unsigned char x = A[i], y = B[i];
flow_counter++;
diff |= x ^ y;
}
for( i = start_offset; i < num; i++ )
{
unsigned char x = A[i], y = B[i];
flow_counter++;
diff |= x ^ y;
}
for( i = 0; i < start_offset; i++ )
{
unsigned char x = A[i], y = B[i];
flow_counter++;
diff |= x ^ y;
}
}
/* Return 0 only when diff is 0 and flow_counter is equal to num */
return( (int) diff | (int) ( flow_counter ^ num ) );
}
@ -340,18 +346,7 @@ void mbedtls_platform_random_buf( uint8_t *buf, size_t len )
uint32_t mbedtls_platform_random_in_range( uint32_t num )
{
uint32_t result;
if( num <= 1 )
{
result = 0;
}
else
{
result = mbedtls_platform_random_uint32() % num;
}
return( result );
return mbedtls_platform_random_uint32() % num;
}
void mbedtls_platform_random_delay( void )