aes: improve driver (#133)

* do checks on size & addr alignment
* increase block size to the maximum size the aes engine can handle
* reduce memory footprint

Author: DacoTaco

gc/ogc/aes.h

@@ -35,7 +35,7 @@ distribution.
 #include <gctypes.h>
 #include <gcutil.h>
 
-#define AES_BLOCK_SIZE 128
+#define AES_BLOCK_SIZE 0x10000
 
 #ifdef __cplusplus
 	extern "C" {

libogc/aes.c

@@ -34,7 +34,7 @@ distribution.
 #include "ipc.h"
 #include "aes.h"
 
-#define AES_HEAPSIZE 0x1000
+#define AES_HEAPSIZE 0x400
 
 #define AES_IOCTLV_ENCRYPT 2
 #define AES_IOCTLV_DECRYPT 3
@@ -45,33 +45,32 @@ static s32 __aes_hid = -1;
 static s32 AES_ExecuteCommand(s32 command, const void* key, u32 key_size, const void* iv, u32 iv_size, const void* in_data, void* out_data, u32 data_size)
 {
 	ioctlv* params = (ioctlv*)iosAlloc(__aes_hid, sizeof(ioctlv) * 4);
-	void* tmpiv = iosAlloc(__aes_hid, 16);
-	void* block = iosAlloc(__aes_hid, AES_BLOCK_SIZE);
-	if (!params || !tmpiv || !block)
+	void* tmpiv = iosAlloc(__aes_hid, iv_size);
+	if (!params || !tmpiv)
 		return -1;
 
-	memcpy(tmpiv, iv, 16);
-
+	memcpy(tmpiv, iv, iv_size);
+	
 	s32 ret = -1;
 	for (u32 i = 0; i < data_size; i += AES_BLOCK_SIZE) {
-		memcpy(block, (void*)((u32)in_data + i), AES_BLOCK_SIZE);
+		u32 size = i+AES_BLOCK_SIZE >= data_size
+            ? data_size - i
+            : AES_BLOCK_SIZE;
 
-		params[0].data	= block;
-		params[0].len	= AES_BLOCK_SIZE;
+		params[0].data	= (void*)((u32)in_data + i);
+		params[0].len	= size;
 		params[1].data	= (void*) key;
 		params[1].len	= key_size;
-		params[2].data	= block;
-		params[2].len	= AES_BLOCK_SIZE;
+		params[2].data	= (void*)((u32)out_data + i);
+		params[2].len	= size;
 		params[3].data	= tmpiv;
-		params[3].len	= 16;
+		params[3].len	= iv_size;
+
 		ret = IOS_Ioctlv(__aes_fd, command, 2, 2, params);
 		if (ret < 0)
 			break;
-
-		memcpy((void*)((u32)out_data + i), block, AES_BLOCK_SIZE);
 	}
 
-	iosFree(__aes_hid, block);
 	iosFree(__aes_hid, tmpiv);
 	iosFree(__aes_hid, params);
 	return ret;
@@ -112,16 +111,22 @@ s32 AES_Close(void)
 
 s32 AES_Encrypt(const void* key, u32 key_size, const void* iv, u32 iv_size, const void* in_data, void* out_data, u32 data_size)
 {
-	if (key_size != 16 || iv_size != 16)
-		return -1;
+	if(((u32)in_data & 0x1f) != 0 || ((u32)out_data & 0x1f) != 0)
+		return -4;
+	
+	if (key_size != 16 || iv_size != 16 || (data_size & 15) != 0)
+		return -4;
 
 	return AES_ExecuteCommand(AES_IOCTLV_ENCRYPT, key, key_size, iv, iv_size, in_data, out_data, data_size);
 }
 
 s32 AES_Decrypt(const void* key, u32 key_size, const void* iv, u32 iv_size, const void* in_data, void* out_data, u32 data_size)
 {
-	if (key_size != 16 || iv_size != 16)
-		return -1;
+	if(((u32)in_data & 0x1f) != 0 || ((u32)out_data & 0x1f) != 0)
+		return -4;
+	
+    if (key_size != 16 || iv_size != 16 || (data_size & 15) != 0)
+		return -4;
 
 	return AES_ExecuteCommand(AES_IOCTLV_DECRYPT, key, key_size, iv, iv_size, in_data, out_data, data_size);
 }