From 5ffc1ec42357745c34abff14222c5603e686fb2d Mon Sep 17 00:00:00 2001
From: Tobias Brunner <tobias@strongswan.org>
Date: Fri, 29 Jan 2021 16:48:03 +0100
Subject: [PATCH] botan: Extract helper function to map RNG quality to Botan
 RNG names

---
 src/libstrongswan/plugins/botan/botan_rng.c  | 26 +++-------------
 src/libstrongswan/plugins/botan/botan_util.c | 32 ++++++++++++++++++++
 src/libstrongswan/plugins/botan/botan_util.h |  8 +++++
 3 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/src/libstrongswan/plugins/botan/botan_rng.c b/src/libstrongswan/plugins/botan/botan_rng.c
index c49225c3c..9d88b77a9 100644
--- a/src/libstrongswan/plugins/botan/botan_rng.c
+++ b/src/libstrongswan/plugins/botan/botan_rng.c
@@ -22,6 +22,7 @@
  */
 
 #include "botan_rng.h"
+#include "botan_util.h"
 
 #include <botan/build.h>
 
@@ -83,29 +84,12 @@ METHOD(rng_t, destroy, void,
 botan_random_t *botan_rng_create(rng_quality_t quality)
 {
 	private_botan_random_t *this;
-	const char* rng_name;
+	const char *rng_name;
 
-	switch (quality)
+	rng_name = botan_map_rng_quality(quality);
+	if (!rng_name)
 	{
-		case RNG_WEAK:
-		case RNG_STRONG:
-			/* some rng_t instances of this class (e.g. in the ike-sa-manager)
-			 * may be called concurrently by different threads. the Botan RNGs
-			 * are not reentrant, by default, so use the threadsafe version.
-			 * because we build without threading support when running tests
-			 * with leak-detective (lots of reports of frees of unknown memory)
-			 * there is a fallback to the default */
-#ifdef BOTAN_TARGET_OS_HAS_THREADS
-			rng_name = "user-threadsafe";
-#else
-			rng_name = "user";
-#endif
-			break;
-		case RNG_TRUE:
-			rng_name = "system";
-			break;
-		default:
-			return NULL;
+		return NULL;
 	}
 
 	INIT(this,
diff --git a/src/libstrongswan/plugins/botan/botan_util.c b/src/libstrongswan/plugins/botan/botan_util.c
index f5728e43e..9414a2cc8 100644
--- a/src/libstrongswan/plugins/botan/botan_util.c
+++ b/src/libstrongswan/plugins/botan/botan_util.c
@@ -313,3 +313,35 @@ bool botan_dh_key_derivation(botan_privkey_t key, chunk_t pub, chunk_t *secret)
 	botan_pk_op_key_agreement_destroy(ka);
 	return TRUE;
 }
+
+/*
+ * Described in header
+ */
+const char *botan_map_rng_quality(rng_quality_t quality)
+{
+	const char *rng_name;
+
+	switch (quality)
+	{
+		case RNG_WEAK:
+		case RNG_STRONG:
+			/* some rng_t instances of this class (e.g. in the ike-sa-manager)
+			 * may be called concurrently by different threads. the Botan RNGs
+			 * are not reentrant, by default, so use the threadsafe version.
+			 * because we build without threading support when running tests
+			 * with leak-detective (lots of reports of frees of unknown memory)
+			 * there is a fallback to the default */
+#ifdef BOTAN_TARGET_OS_HAS_THREADS
+			rng_name = "user-threadsafe";
+#else
+			rng_name = "user";
+#endif
+			break;
+		case RNG_TRUE:
+			rng_name = "system";
+			break;
+		default:
+			return NULL;
+	}
+	return rng_name;
+}
diff --git a/src/libstrongswan/plugins/botan/botan_util.h b/src/libstrongswan/plugins/botan/botan_util.h
index 7fb74ec5d..fe8a9a8ee 100644
--- a/src/libstrongswan/plugins/botan/botan_util.h
+++ b/src/libstrongswan/plugins/botan/botan_util.h
@@ -125,4 +125,12 @@ bool botan_verify_signature(botan_pubkey_t key, const char* scheme,
  */
 bool botan_dh_key_derivation(botan_privkey_t key, chunk_t pub, chunk_t *secret);
 
+/**
+ * Map the given RNG quality to a name as used by Botan.
+ *
+ * @param quality	RNG quality
+ * @return			name of the Botan RNG
+ */
+const char *botan_map_rng_quality(rng_quality_t quality);
+
 #endif /** BOTAN_UTIL_H_ @}*/