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>
diff --git a/tests/suites/test_suite_pkparse.function b/tests/suites/test_suite_pkparse.function
index 4650d33..4c7f3d2 100644
--- a/tests/suites/test_suite_pkparse.function
+++ b/tests/suites/test_suite_pkparse.function
@@ -21,7 +21,8 @@
     if( strcmp( pwd, "NULL" ) == 0 )
         pwd = NULL;
 
-    res = mbedtls_pk_parse_keyfile( &ctx, key_file, pwd );
+    res = mbedtls_pk_parse_keyfile( &ctx, key_file, pwd,
+            mbedtls_test_rnd_std_rand, NULL );
 
     TEST_ASSERT( res == result );
 
@@ -96,7 +97,8 @@
 
     mbedtls_pk_init( &ctx );
 
-    res = mbedtls_pk_parse_keyfile( &ctx, key_file, password );
+    res = mbedtls_pk_parse_keyfile( &ctx, key_file, password,
+            mbedtls_test_rnd_std_rand, NULL );
 
     TEST_ASSERT( res == result );
 
@@ -120,7 +122,8 @@
 
     mbedtls_pk_init( &pk );
 
-    TEST_ASSERT( mbedtls_pk_parse_key( &pk, buf->x, buf->len, NULL, 0 ) == result );
+    TEST_ASSERT( mbedtls_pk_parse_key( &pk, buf->x, buf->len, NULL, 0,
+                        mbedtls_test_rnd_std_rand, NULL ) == result );
 
 exit:
     mbedtls_pk_free( &pk );