ssl_client2: Add helper to unhexify binary command line data
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 62f2c57..894a8e0 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -708,6 +708,45 @@
return( 0 );
}
+/* Unhexify `hex` into `dst`. `dst` must have
+ * size at least `strlen( hex ) / 2`. */
+int unhexify( unsigned char const *hex, unsigned char *dst )
+{
+ unsigned char c;
+ size_t j;
+ size_t len = strlen( hex );
+
+ if( len % 2 != 0 )
+ return( -1 );
+
+ for( j = 0; j < len; j += 2 )
+ {
+ c = hex[j];
+ if( c >= '0' && c <= '9' )
+ c -= '0';
+ else if( c >= 'a' && c <= 'f' )
+ c -= 'a' - 10;
+ else if( c >= 'A' && c <= 'F' )
+ c -= 'A' - 10;
+ else
+ return( -1 );
+ dst[ j / 2 ] = c << 4;
+
+ c = hex[j + 1];
+ if( c >= '0' && c <= '9' )
+ c -= '0';
+ else if( c >= 'a' && c <= 'f' )
+ c -= 'a' - 10;
+ else if( c >= 'A' && c <= 'F' )
+ c -= 'A' - 10;
+ else
+ return( -1 );
+ dst[ j / 2 ] |= c;
+ }
+
+ return( 0 );
+}
+
int main( int argc, char *argv[] )
{
int ret = 0, len, tail_len, i, written, frags, retry_left;
@@ -1257,46 +1296,17 @@
*/
if( strlen( opt.psk ) )
{
- unsigned char c;
- size_t j;
-
- if( strlen( opt.psk ) % 2 != 0 )
+ psk_len = strlen( opt.psk ) / 2;
+ if( psk_len > sizeof( psk ) )
{
- mbedtls_printf( "pre-shared key not valid hex\n" );
+ mbedtls_printf( "pre-shared key too long\n" );
goto exit;
}
- psk_len = strlen( opt.psk ) / 2;
-
- for( j = 0; j < strlen( opt.psk ); j += 2 )
+ if( unhexify( opt.psk, psk ) != 0 )
{
- c = opt.psk[j];
- if( c >= '0' && c <= '9' )
- c -= '0';
- else if( c >= 'a' && c <= 'f' )
- c -= 'a' - 10;
- else if( c >= 'A' && c <= 'F' )
- c -= 'A' - 10;
- else
- {
- mbedtls_printf( "pre-shared key not valid hex\n" );
- goto exit;
- }
- psk[ j / 2 ] = c << 4;
-
- c = opt.psk[j + 1];
- if( c >= '0' && c <= '9' )
- c -= '0';
- else if( c >= 'a' && c <= 'f' )
- c -= 'a' - 10;
- else if( c >= 'A' && c <= 'F' )
- c -= 'A' - 10;
- else
- {
- mbedtls_printf( "pre-shared key not valid hex\n" );
- goto exit;
- }
- psk[ j / 2 ] |= c;
+ mbedtls_printf( "pre-shared key not valid hex\n" );
+ goto exit;
}
}
#endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
