Add RNG params to private key parsing

This is necessary for the case where the public part of an EC keypair
needs to be computed from the private part - either because it was not
included (it's an optional component) or because it was compressed (a
format we can't parse).

This changes the API of two public functions: mbedtls_pk_parse_key() and
mbedtls_pk_parse_keyfile().

Tests and programs have been adapted. Some programs use a non-secure RNG
(from the test library) just to get things to compile and run; in a
future commit this should be improved in order to demonstrate best
practice.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>

programs/pkey/key_app.c

@@ -40,6 +40,8 @@
 #include "mbedtls/rsa.h"
 #include "mbedtls/pk.h"
 
+#include "test/random.h"
+
 #include <string.h>
 #endif
 
@@ -181,7 +183,8 @@ int main( int argc, char *argv[] )
         mbedtls_printf( "\n  . Loading the private key ..." );
         fflush( stdout );
 
-        ret = mbedtls_pk_parse_keyfile( &pk, opt.filename, opt.password );
+        ret = mbedtls_pk_parse_keyfile( &pk, opt.filename, opt.password,
+                                        mbedtls_test_rnd_std_rand, NULL );
 
         if( ret != 0 )
         {