From ff5b02d3711d19e5d1d47067364e5e4df25b25a6 Mon Sep 17 00:00:00 2001
From: Karel Miko <karel.miko@gmail.com>
Date: Thu, 30 Mar 2017 20:44:39 +0200
Subject: [PATCH] LTC_CHACHA vs. LTC_CHACHA20_PRNG

---
 src/headers/tomcrypt_custom.h | 7 +++++++
 src/headers/tomcrypt_prng.h   | 6 +++---
 src/misc/crypt/crypt.c        | 3 +++
 src/misc/crypt/crypt_sizes.c  | 2 +-
 src/prngs/chacha.c            | 2 +-
 5 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/headers/tomcrypt_custom.h b/src/headers/tomcrypt_custom.h
index 1d55322..5039113 100644
--- a/src/headers/tomcrypt_custom.h
+++ b/src/headers/tomcrypt_custom.h
@@ -294,6 +294,9 @@
 /* The LTC_RC4 stream cipher */
 #define LTC_RC4
 
+/* The ChaCha20 stream cipher based PRNG */
+#define LTC_CHACHA20_PRNG
+
 /* Fortuna PRNG */
 #define LTC_FORTUNA
 
@@ -512,6 +515,10 @@
    #error LTC_CHACHA20POLY1305_MODE requires LTC_CHACHA + LTC_POLY1305
 #endif
 
+#if defined(LTC_CHACHA20_PRNG) && !defined(LTC_CHACHA)
+   #error LTC_CHACHA20_PRNG requires LTC_CHACHA
+#endif
+
 /* THREAD management */
 #ifdef LTC_PTHREAD
 
diff --git a/src/headers/tomcrypt_prng.h b/src/headers/tomcrypt_prng.h
index 7661d3f..93ae366 100644
--- a/src/headers/tomcrypt_prng.h
+++ b/src/headers/tomcrypt_prng.h
@@ -15,7 +15,7 @@ struct rc4_prng {
 };
 #endif
 
-#ifdef LTC_CHACHA
+#ifdef LTC_CHACHA20_PRNG
 struct chacha20_prng {
     chacha_state s;        /* chacha state */
     unsigned char ent[40]; /* entropy buffer */
@@ -64,7 +64,7 @@ typedef union Prng_state {
 #ifdef LTC_RC4
     struct rc4_prng       rc4;
 #endif
-#ifdef LTC_CHACHA
+#ifdef LTC_CHACHA20_PRNG
     struct chacha20_prng  chacha;
 #endif
 #ifdef LTC_FORTUNA
@@ -166,7 +166,7 @@ int  rc4_test(void);
 extern const struct ltc_prng_descriptor rc4_desc;
 #endif
 
-#ifdef LTC_CHACHA
+#ifdef LTC_CHACHA20_PRNG
 int chacha_prng_start(prng_state *prng);
 int chacha_prng_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng);
 int chacha_prng_ready(prng_state *prng);
diff --git a/src/misc/crypt/crypt.c b/src/misc/crypt/crypt.c
index d97d101..7cca541 100644
--- a/src/misc/crypt/crypt.c
+++ b/src/misc/crypt/crypt.c
@@ -274,6 +274,9 @@ const char *crypt_build_settings =
 #if defined(LTC_RC4)
     "   RC4\n"
 #endif
+#if defined(LTC_CHACHA20_PRNG)
+    "   ChaCha20\n"
+#endif
 #if defined(LTC_FORTUNA)
     "   Fortuna (" NAME_VALUE(LTC_FORTUNA_POOLS) ", " NAME_VALUE(LTC_FORTUNA_WD) ")\n"
 #endif
diff --git a/src/misc/crypt/crypt_sizes.c b/src/misc/crypt/crypt_sizes.c
index 65265d3..ae5b308 100755
--- a/src/misc/crypt/crypt_sizes.c
+++ b/src/misc/crypt/crypt_sizes.c
@@ -223,7 +223,7 @@ static const crypt_size _crypt_sizes[] = {
 #ifdef LTC_FORTUNA
     _SZ_STRINGIFY_S(fortuna_prng),
 #endif
-#ifdef LTC_CHACHA
+#ifdef LTC_CHACHA20_PRNG
     _SZ_STRINGIFY_S(chacha20_prng),
 #endif
 #ifdef LTC_RC4
diff --git a/src/prngs/chacha.c b/src/prngs/chacha.c
index 5a2ad55..4ce6747 100644
--- a/src/prngs/chacha.c
+++ b/src/prngs/chacha.c
@@ -9,7 +9,7 @@
 
 #include "tomcrypt.h"
 
-#ifdef LTC_CHACHA
+#ifdef LTC_CHACHA20_PRNG
 
 const struct ltc_prng_descriptor chacha_prng_desc =
 {