From 49c57dfe0ad6d975cd30e2525269c8c783159d7d Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Fri, 26 Feb 2016 13:15:36 +0100
Subject: [PATCH] Faster HChaCha20

---
 .../crypto_core/hchacha20/core_hchacha20.c    | 80 +++++++++++++------
 .../crypto_core/hchacha20/core_hchacha20.h    | 14 ----
 2 files changed, 56 insertions(+), 38 deletions(-)

diff --git a/src/libsodium/crypto_core/hchacha20/core_hchacha20.c b/src/libsodium/crypto_core/hchacha20/core_hchacha20.c
index 93c190a3..13e67396 100644
--- a/src/libsodium/crypto_core/hchacha20/core_hchacha20.c
+++ b/src/libsodium/crypto_core/hchacha20/core_hchacha20.c
@@ -1,10 +1,42 @@
 
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "core_hchacha20.h"
 #include "crypto_core_hchacha20.h"
 
+static inline uint32_t
+load32(const void *src)
+{
+#ifdef NATIVE_LITTLE_ENDIAN
+    uint32_t w;
+    memcpy(&w, src, sizeof w);
+    return w;
+#else
+    const uint8_t *p = (const uint8_t *) src;
+    uint32_t w = *p++;
+    w |= (uint32_t)(*p++) <<  8;
+    w |= (uint32_t)(*p++) << 16;
+    w |= (uint32_t)(*p++) << 24;
+    return w;
+#endif
+}
+
+static inline void
+store32(void *dst, uint32_t w)
+{
+#ifdef NATIVE_LITTLE_ENDIAN
+    memcpy(dst, &w, sizeof w);
+#else
+    uint8_t *p = (uint8_t *) dst;
+    *p++ = (uint8_t) w; w >>= 8;
+    *p++ = (uint8_t) w; w >>= 8;
+    *p++ = (uint8_t) w; w >>= 8;
+    *p++ = (uint8_t) w;
+#endif
+}
+
 int
 crypto_core_hchacha20(unsigned char *out, const unsigned char *in,
                       const unsigned char *k, const unsigned char *c)
@@ -19,23 +51,23 @@ crypto_core_hchacha20(unsigned char *out, const unsigned char *in,
         x2 = U32C(0x79622d32);
         x3 = U32C(0x6b206574);
     } else {
-        x0 = U8TO32_LITTLE(c +  0);
-        x1 = U8TO32_LITTLE(c +  4);
-        x2 = U8TO32_LITTLE(c +  8);
-        x3 = U8TO32_LITTLE(c + 12);
+        x0 = load32(c +  0);
+        x1 = load32(c +  4);
+        x2 = load32(c +  8);
+        x3 = load32(c + 12);
     }
-    x4  = U8TO32_LITTLE(k +  0);
-    x5  = U8TO32_LITTLE(k +  4);
-    x6  = U8TO32_LITTLE(k +  8);
-    x7  = U8TO32_LITTLE(k + 12);
-    x8  = U8TO32_LITTLE(k + 16);
-    x9  = U8TO32_LITTLE(k + 20);
-    x10 = U8TO32_LITTLE(k + 24);
-    x11 = U8TO32_LITTLE(k + 28);
-    x12 = U8TO32_LITTLE(in +  0);
-    x13 = U8TO32_LITTLE(in +  4);
-    x14 = U8TO32_LITTLE(in +  8);
-    x15 = U8TO32_LITTLE(in + 12);
+    x4  = load32(k +  0);
+    x5  = load32(k +  4);
+    x6  = load32(k +  8);
+    x7  = load32(k + 12);
+    x8  = load32(k + 16);
+    x9  = load32(k + 20);
+    x10 = load32(k + 24);
+    x11 = load32(k + 28);
+    x12 = load32(in +  0);
+    x13 = load32(in +  4);
+    x14 = load32(in +  8);
+    x15 = load32(in + 12);
 
     for (i = 0; i < 10; i++) {
         QUARTERROUND(x0, x4,  x8, x12);
@@ -48,14 +80,14 @@ crypto_core_hchacha20(unsigned char *out, const unsigned char *in,
         QUARTERROUND(x3, x4,  x9, x14);
     }
 
-    U32TO8_LITTLE(out +  0, x0);
-    U32TO8_LITTLE(out +  4, x1);
-    U32TO8_LITTLE(out +  8, x2);
-    U32TO8_LITTLE(out + 12, x3);
-    U32TO8_LITTLE(out + 16, x12);
-    U32TO8_LITTLE(out + 20, x13);
-    U32TO8_LITTLE(out + 24, x14);
-    U32TO8_LITTLE(out + 28, x15);
+    store32(out +  0, x0);
+    store32(out +  4, x1);
+    store32(out +  8, x2);
+    store32(out + 12, x3);
+    store32(out + 16, x12);
+    store32(out + 20, x13);
+    store32(out + 24, x14);
+    store32(out + 28, x15);
 
     return 0;
 }
diff --git a/src/libsodium/crypto_core/hchacha20/core_hchacha20.h b/src/libsodium/crypto_core/hchacha20/core_hchacha20.h
index 12aac7df..c1419f3c 100644
--- a/src/libsodium/crypto_core/hchacha20/core_hchacha20.h
+++ b/src/libsodium/crypto_core/hchacha20/core_hchacha20.h
@@ -9,20 +9,6 @@
 
 #define ROTL32(v, n) (U32V((v) << (n)) | ((v) >> (32 - (n))))
 
-#define U8TO32_LITTLE(p) \
-  (((uint32_t)((p)[0])      ) | \
-   ((uint32_t)((p)[1]) <<  8) | \
-   ((uint32_t)((p)[2]) << 16) | \
-   ((uint32_t)((p)[3]) << 24))
-
-#define U32TO8_LITTLE(p, v) \
-  do { \
-    (p)[0] = U8V((v)      ); \
-    (p)[1] = U8V((v) >>  8); \
-    (p)[2] = U8V((v) >> 16); \
-    (p)[3] = U8V((v) >> 24); \
-  } while (0)
-
 #define ROTATE(v, c) (ROTL32(v, c))
 #define XOR(v, w)    ((v) ^ (w))
 #define PLUS(v, w)   (U32V((v) + (w)))