From 0b4fb379d408bdb0abd8f14ba3f112c820d2327b Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Sun, 18 Jan 2015 10:08:36 +0100
Subject: [PATCH] Factorize randombytes_uniform() Don't require randombytes
 implementations to reimplement this. NULL can be passed instead of a function
 pointer to use the default implementation. Allow NULL for randombytes_stir()
 and randombytes_close() as well.

---
 src/libsodium/randombytes/randombytes.c       | 22 +++++++------
 .../salsa20/randombytes_salsa20_random.c      | 24 +-------------
 .../sysrandom/randombytes_sysrandom.c         | 32 ++-----------------
 3 files changed, 16 insertions(+), 62 deletions(-)

diff --git a/src/libsodium/randombytes/randombytes.c b/src/libsodium/randombytes/randombytes.c
index baee86ff..314e9d02 100644
--- a/src/libsodium/randombytes/randombytes.c
+++ b/src/libsodium/randombytes/randombytes.c
@@ -79,17 +79,25 @@ randombytes_stir(void)
         }
     });
 #else
-    implementation->stir();
+    if (implementation != NULL && implementation->stir != NULL) {
+        implementation->stir();
+    }
 #endif
 }
 
+/*
+ * randombytes_uniform() derives from OpenBSD's arc4random_uniform()
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ */
 uint32_t
 randombytes_uniform(const uint32_t upper_bound)
 {
-#ifdef __EMSCRIPTEN__
     uint32_t min;
     uint32_t r;
 
+    if (implementation != NULL && implementation->uniform != NULL) {
+        return implementation->uniform(upper_bound);
+    }
     if (upper_bound < 2) {
         return 0;
     }
@@ -99,9 +107,6 @@ randombytes_uniform(const uint32_t upper_bound)
     } while (r < min);
 
     return r % upper_bound;
-#else
-    return implementation->uniform(upper_bound);
-#endif
 }
 
 void
@@ -124,11 +129,10 @@ randombytes_buf(void * const buf, const size_t size)
 int
 randombytes_close(void)
 {
-#ifdef __EMSCRIPTEN__
+    if (implementation != NULL && implementation->close != NULL) {
+        return implementation->close();
+    }
     return 0;
-#else
-    return implementation->close();
-#endif
 }
 
 void
diff --git a/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c b/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
index e81fa92d..4e51381f 100644
--- a/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
+++ b/src/libsodium/randombytes/salsa20/randombytes_salsa20_random.c
@@ -311,28 +311,6 @@ randombytes_salsa20_random_buf(void * const buf, const size_t size)
                               (unsigned char *) &stream.nonce, stream.key);
 }
 
-/*
- * randombytes_salsa20_random_uniform() derives from OpenBSD's arc4random_uniform()
- * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
- */
-
-uint32_t
-randombytes_salsa20_random_uniform(const uint32_t upper_bound)
-{
-    uint32_t min;
-    uint32_t r;
-
-    if (upper_bound < 2) {
-        return 0;
-    }
-    min = (uint32_t) (-upper_bound % upper_bound);
-    do {
-        r = randombytes_salsa20_random();
-    } while (r < min); /* LCOV_EXCL_LINE */
-
-    return r % upper_bound;
-}
-
 const char *
 randombytes_salsa20_implementation_name(void)
 {
@@ -343,7 +321,7 @@ struct randombytes_implementation randombytes_salsa20_implementation = {
     SODIUM_C99(.implementation_name =) randombytes_salsa20_implementation_name,
     SODIUM_C99(.random =) randombytes_salsa20_random,
     SODIUM_C99(.stir =) randombytes_salsa20_random_stir,
-    SODIUM_C99(.uniform =) randombytes_salsa20_random_uniform,
+    SODIUM_C99(.uniform =) NULL,
     SODIUM_C99(.buf =) randombytes_salsa20_random_buf,
     SODIUM_C99(.close =) randombytes_salsa20_random_close
 };
diff --git a/src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c b/src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c
index 539ebca6..6d2ea718 100644
--- a/src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c
+++ b/src/libsodium/randombytes/sysrandom/randombytes_sysrandom.c
@@ -43,12 +43,6 @@ randombytes_sysrandom_stir(void)
 {
 }
 
-uint32_t
-randombytes_sysrandom_uniform(const uint32_t upper_bound)
-{
-    return arc4random_uniform(upper_bound);
-}
-
 void
 randombytes_sysrandom_buf(void * const buf, const size_t size)
 {
@@ -224,29 +218,7 @@ randombytes_sysrandom_buf(void * const buf, const size_t size)
 #endif
 }
 
-/*
- * randombytes_sysrandom_uniform() derives from OpenBSD's arc4random_uniform()
- * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
- */
-
-uint32_t
-randombytes_sysrandom_uniform(const uint32_t upper_bound)
-{
-    uint32_t min;
-    uint32_t r;
-
-    if (upper_bound < 2) {
-        return 0;
-    }
-    min = (uint32_t) (-upper_bound % upper_bound);
-    do {
-        r = randombytes_sysrandom();
-    } while (r < min); /* LCOV_EXCL_LINE */
-
-    return r % upper_bound;
-}
-
-#endif
+#endif /* __OpenBSD__ */
 
 const char *
 randombytes_sysrandom_implementation_name(void)
@@ -258,7 +230,7 @@ struct randombytes_implementation randombytes_sysrandom_implementation = {
     SODIUM_C99(.implementation_name =) randombytes_sysrandom_implementation_name,
     SODIUM_C99(.random =) randombytes_sysrandom,
     SODIUM_C99(.stir =) randombytes_sysrandom_stir,
-    SODIUM_C99(.uniform =) randombytes_sysrandom_uniform,
+    SODIUM_C99(.uniform =) NULL,
     SODIUM_C99(.buf =) randombytes_sysrandom_buf,
     SODIUM_C99(.close =) randombytes_sysrandom_close
 };