Fix Wiimote crypto

include/utils.h

@@ -45,6 +45,14 @@ static inline int memmismatch(const void *restrict a, const void *restrict b, in
 	return i;
 }
 
+static inline void reverse_memcpy(void *restrict dst, const void *restrict src, int size)
+{
+	u8 *d = dst;
+	const u8 *s = src;
+	for (int i = 0; i < size; i++)
+		d[i] = s[size - 1 - i];
+}
+
 /* Message injection helpers */
 int inject_msg_to_usb_intr_ready_queue(void *msg);
 int inject_msg_to_usb_bulk_in_ready_queue(void *msg);

source/wiimote_crypto.c

@@ -4,6 +4,7 @@
 // Copyright (C) Hector Martin "marcan" ([email protected])
 
 #include <string.h>
+#include "utils.h"
 #include "wiimote_crypto.h"
 
 /* Code ported from:
@@ -196,6 +197,7 @@ static const sbox_t sboxes_1st_party[] = {
 
 static inline u8 ror8(u8 word, unsigned int shift)
 {
+	shift %= 8;
 	return (word >> shift) | (word << (8 - shift));
 }
 
@@ -249,8 +251,8 @@ void wiimote_crypto_generate_key_from_extension_key_data(struct wiimote_encrypti
 	u8 key[6], check_key[6];
 	u32 idx;
 
-	memcpy(rand, key_data, sizeof(rand));
-	memcpy(key, key_data + sizeof(rand), sizeof(key));
+	reverse_memcpy(rand, key_data, sizeof(rand));
+	reverse_memcpy(key, key_data + sizeof(rand), sizeof(key));
 
 	/* Bruteforcing */
 	for (idx = 0; idx != 7; ++idx) {