From 6d9f2cae7956dc8c614ca9e8e6fa24c9ab0458eb Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Tue, 29 Dec 2015 19:00:52 +0100
Subject: [PATCH] argon2: ensure that memory is cacheline aligned; use mmap(2)
 if possible

---
 .../crypto_pwhash/argon2/argon2-core.c        | 43 +++++++++++++++++--
 1 file changed, 40 insertions(+), 3 deletions(-)

diff --git a/src/libsodium/crypto_pwhash/argon2/argon2-core.c b/src/libsodium/crypto_pwhash/argon2/argon2-core.c
index aced92bd..b8f5327f 100644
--- a/src/libsodium/crypto_pwhash/argon2/argon2-core.c
+++ b/src/libsodium/crypto_pwhash/argon2/argon2-core.c
@@ -66,6 +66,7 @@ static void store_block(void *output, const block *src) {
 
 /***************Memory allocators*****************/
 int allocate_memory(block_region **region, uint32_t m_cost) {
+    void *base;
     block *memory;
     size_t memory_size;
 
@@ -82,11 +83,39 @@ int allocate_memory(block_region **region, uint32_t m_cost) {
         return ARGON2_MEMORY_ALLOCATION_ERROR;
     }
 
-    memory = (block *)malloc(memory_size); /*3. Try to allocate block*/
+#if defined(MAP_ANON) && defined(HAVE_MMAP)
+	if ((base = mmap(NULL, memory_size, PROT_READ | PROT_WRITE,
+# ifdef MAP_NOCORE
+                     MAP_ANON | MAP_PRIVATE | MAP_NOCORE,
+# else
+                     MAP_ANON | MAP_PRIVATE,
+# endif
+                     -1, 0)) == MAP_FAILED) {
+		base = NULL; /* LCOV_EXCL_LINE */
+    }
+    memcpy(&memory, &base, sizeof memory);
+#elif defined(HAVE_POSIX_MEMALIGN)
+	if ((errno = posix_memalign((void **) &base, 64, memory_size)) != 0) {
+		base = NULL;
+    }
+    memcpy(&memory, &base, sizeof memory);
+#else
+    memory = NULL;
+	if (size + 63 < size) {
+        base = NULL;
+		errno = ENOMEM;
+    } else if ((base = malloc(memory_size + 63)) != NULL) {
+        uint8_t *aligned = ((uint8_t *) base) + 63;
+		aligned -= (uintptr_t) aligned & 63;
+        memcpy(&memory, &aligned, sizeof memory);
+	}
+#endif
     if (!memory) {
         return ARGON2_MEMORY_ALLOCATION_ERROR;
     }
-    (*region)->memory = memory;
+	(*region)->base = base;
+	(*region)->memory = memory;
+	(*region)->size = base ? memory_size : 0;
 
     return ARGON2_OK;
 }
@@ -101,7 +130,15 @@ void clear_memory(argon2_instance_t *instance, int clear) {
 }
 
 void free_memory(block_region *region) {
-    free(region->memory);
+	if (region->base) {
+#if defined(MAP_ANON) && defined(HAVE_MMAP)
+		if (munmap(region->base, region->size)) {
+			return; /* LCOV_EXCL_LINE */
+        }
+#else
+		free(region->base);
+#endif
+	}
     free(region);
 }