From 843c560003b288a073f528ef16b83541f7a9b0ac Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter.wuille@gmail.com>
Date: Tue, 10 Jan 2017 14:14:01 -0800
Subject: [PATCH] Avoid unaligned access in crypto i/o

---
 src/crypto/common.h | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/src/crypto/common.h b/src/crypto/common.h
index 580c72f5a64..4a9d1150b67 100644
--- a/src/crypto/common.h
+++ b/src/crypto/common.h
@@ -10,57 +10,73 @@
 #endif
 
 #include <stdint.h>
+#include <string.h>
 
 #include "compat/endian.h"
 
 uint16_t static inline ReadLE16(const unsigned char* ptr)
 {
-    return le16toh(*((uint16_t*)ptr));
+    uint16_t x;
+    memcpy((char*)&x, ptr, 2);
+    return le16toh(x);
 }
 
 uint32_t static inline ReadLE32(const unsigned char* ptr)
 {
-    return le32toh(*((uint32_t*)ptr));
+    uint32_t x;
+    memcpy((char*)&x, ptr, 4);
+    return le32toh(x);
 }
 
 uint64_t static inline ReadLE64(const unsigned char* ptr)
 {
-    return le64toh(*((uint64_t*)ptr));
+    uint64_t x;
+    memcpy((char*)&x, ptr, 8);
+    return le64toh(x);
 }
 
 void static inline WriteLE16(unsigned char* ptr, uint16_t x)
 {
-    *((uint16_t*)ptr) = htole16(x);
+    uint16_t v = htole16(x);
+    memcpy(ptr, (char*)&v, 2);
 }
 
 void static inline WriteLE32(unsigned char* ptr, uint32_t x)
 {
-    *((uint32_t*)ptr) = htole32(x);
+    uint32_t v = htole32(x);
+    memcpy(ptr, (char*)&v, 4);
 }
 
 void static inline WriteLE64(unsigned char* ptr, uint64_t x)
 {
-    *((uint64_t*)ptr) = htole64(x);
+    uint64_t v = htole64(x);
+    memcpy(ptr, (char*)&v, 8);
 }
 
 uint32_t static inline ReadBE32(const unsigned char* ptr)
 {
-    return be32toh(*((uint32_t*)ptr));
+    uint32_t x;
+    memcpy((char*)&x, ptr, 4);
+    return be32toh(x);
 }
 
 uint64_t static inline ReadBE64(const unsigned char* ptr)
 {
-    return be64toh(*((uint64_t*)ptr));
+    uint64_t x;
+    memcpy((char*)&x, ptr, 8);
+    return be64toh(x);
 }
 
 void static inline WriteBE32(unsigned char* ptr, uint32_t x)
 {
-    *((uint32_t*)ptr) = htobe32(x);
+    uint32_t v = htobe32(x);
+    memcpy(ptr, (char*)&v, 4);
 }
 
 void static inline WriteBE64(unsigned char* ptr, uint64_t x)
 {
-    *((uint64_t*)ptr) = htobe64(x);
+    uint64_t v = htobe64(x);
+    memcpy(ptr, (char*)&v, 8);
 }
 
 #endif // BITCOIN_CRYPTO_COMMON_H