From decfcecc97d707a4265dab939b3af1a0091dee8d Mon Sep 17 00:00:00 2001
From: Davide Beatrici <git@davidebeatrici.dev>
Date: Wed, 12 Aug 2020 00:49:31 +0200
Subject: [PATCH] Cedar: Add ProtoOptionString() in PROTO_IMPL, to generate
 default option values

The WireGuard implementation will have two options that should not have a fixed default value, because they represent two keys (one is preshared, the other is private).

Instead of handling these two options differently in ProtoNewContainer(), this commit adds a new function to PROTO_IMPL: ProtoOptionString().

ProtoOptionString() takes the option's name as argument and returns a heap-allocated string that will be used as value. The function returns NULL when the option doesn't need a randomized value.
---
 src/Cedar/Proto.c         | 2 +-
 src/Cedar/Proto.h         | 1 +
 src/Cedar/Proto_OpenVPN.c | 1 +
 src/Cedar/Proto_SSTP.c    | 1 +
 4 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Cedar/Proto.c b/src/Cedar/Proto.c
index 7023e4c7..d626b9b9 100644
--- a/src/Cedar/Proto.c
+++ b/src/Cedar/Proto.c
@@ -291,7 +291,7 @@ PROTO_CONTAINER *ProtoContainerNew(const PROTO_IMPL *impl)
 			option->Bool = impl_option->Bool;
 			break;
 		case PROTO_OPTION_STRING:
-			option->String = CopyStr(impl_option->String);
+			option->String = impl_option->String != NULL ? CopyStr(impl_option->String) : impl->OptionStringValue(option->Name);
 			break;
 		default:
 			Debug("ProtoContainerNew(): unhandled option type %u!\n", impl_option->Type);
diff --git a/src/Cedar/Proto.h b/src/Cedar/Proto.h
index e0714cab..e14ceced 100644
--- a/src/Cedar/Proto.h
+++ b/src/Cedar/Proto.h
@@ -46,6 +46,7 @@ typedef struct PROTO_IMPL
 {
 	const char *(*Name)();
 	const PROTO_OPTION *(*Options)();
+	char *(*OptionStringValue)(const char *name);
 	bool (*Init)(void **param, const LIST *options, CEDAR *cedar, INTERRUPT_MANAGER *im, SOCK_EVENT *se, const char *cipher, const char *hostname);
 	void (*Free)(void *param);
 	bool (*IsPacketForMe)(const PROTO_MODE mode, const void *data, const UINT size);
diff --git a/src/Cedar/Proto_OpenVPN.c b/src/Cedar/Proto_OpenVPN.c
index a801c4b1..d844ea90 100644
--- a/src/Cedar/Proto_OpenVPN.c
+++ b/src/Cedar/Proto_OpenVPN.c
@@ -20,6 +20,7 @@ const PROTO_IMPL *OvsGetProtoImpl()
 	{
 		OvsName,
 		OvsOptions,
+		NULL,
 		OvsInit,
 		OvsFree,
 		OvsIsPacketForMe,
diff --git a/src/Cedar/Proto_SSTP.c b/src/Cedar/Proto_SSTP.c
index 514ddeda..6c69fb11 100644
--- a/src/Cedar/Proto_SSTP.c
+++ b/src/Cedar/Proto_SSTP.c
@@ -13,6 +13,7 @@ const PROTO_IMPL *SstpGetProtoImpl()
 	{
 		SstpName,
 		SstpOptions,
+		NULL,
 		SstpInit,
 		SstpFree,
 		NULL,