From ca4a5d34175af915ee6c99fbf9134ad94832b803 Mon Sep 17 00:00:00 2001
From: wangyu <wangyu.cn@gmail.com>
Date: Tue, 14 Jul 2020 11:41:21 -0400
Subject: [PATCH] modify scheme of cfb

---
 encrypt.cpp                  | 30 +++++++++++++++++++++++++++++-
 encrypt.h                    |  2 ++
 lib/aes_acc/aesacc.c         |  4 ++--
 lib/aes_faster_c/wrapper.cpp |  4 ++--
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/encrypt.cpp b/encrypt.cpp
index 0df0c01..dced67e 100755
--- a/encrypt.cpp
+++ b/encrypt.cpp
@@ -297,6 +297,28 @@ int de_padding(const char *data ,int &data_len,int padding_num)
 	}
 	return 0;
 }
+void aes_ecb_encrypt(const char *data,char *output)
+{
+	static int first_time=1;
+	char *key=(char*)cipher_key_encrypt;
+	if(aes_key_optimize)
+	{
+		if(first_time==0) key=0;
+		else first_time=0;
+	}	
+	AES_ECB_encrypt_buffer((uint8_t*)data,(uint8_t*)key,(uint8_t*)output);
+}
+void aes_ecb_decrypt(const char *data,char *output)
+{
+	static int first_time=1;
+	char *key=(char*)cipher_key_decrypt;
+	if(aes_key_optimize)
+	{
+		if(first_time==0) key=0;
+		else first_time=0;
+	}	
+	AES_ECB_decrypt_buffer((uint8_t*)data,(uint8_t*)key,(uint8_t*)output);
+}
 int cipher_aes128cbc_encrypt(const char *data,char *output,int &len,char * key)
 {
 	static int first_time=1;
@@ -326,6 +348,7 @@ int cipher_aes128cfb_encrypt(const char *data,char *output,int &len,char * key)
 		if(first_time==0) key=0;
 		else first_time=0;
 	}
+	aes_ecb_encrypt(data,buf); //encrypt the first block
 
 	AES_CFB_encrypt_buffer((unsigned char *)output,(unsigned char *)buf,len,(unsigned char *)key,(unsigned char *)zero_iv);
 	return 0;
@@ -374,7 +397,12 @@ int cipher_aes128cfb_decrypt(const char *data,char *output,int &len,char * key)
 		if(first_time==0) key=0;
 		else first_time=0;
 	}
-	AES_CFB_decrypt_buffer((unsigned char *)output,(unsigned char *)data,len,(unsigned char *)key,(unsigned char *)zero_iv);
+	char buf[buf_len];
+	memcpy(buf,data,len);//TODO inefficient code
+	
+	aes_ecb_decrypt(data,buf); //decrypt the first block
+	
+	AES_CFB_decrypt_buffer((unsigned char *)output,(unsigned char *)buf,len,(unsigned char *)key,(unsigned char *)zero_iv);
 	//if(de_padding(output,len,16)<0) return -1;
 	return 0;
 }
diff --git a/encrypt.h b/encrypt.h
index fc22f17..c02e585 100755
--- a/encrypt.h
+++ b/encrypt.h
@@ -39,4 +39,6 @@ extern char gro_xor[256+100];
 int cipher_decrypt(const char *data,char *output,int &len,char * key);//internal interface ,exposed for test only
 int cipher_encrypt(const char *data,char *output,int &len,char * key);//internal interface ,exposed for test only
 
+void aes_ecb_encrypt(const char *data,char *output);
+void aes_ecb_decrypt(const char *data,char *output);
 #endif
diff --git a/lib/aes_acc/aesacc.c b/lib/aes_acc/aesacc.c
index 236cd13..ca2f379 100644
--- a/lib/aes_acc/aesacc.c
+++ b/lib/aes_acc/aesacc.c
@@ -366,7 +366,7 @@ void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, co
   decrypt_cbc(rk, length, iv_tmp, input, output);
 }
 
-void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output, const uint32_t length)
+void AES_ECB_encrypt_buffer(const uint8_t* input, const uint8_t* key, uint8_t* output)
 {
   static uint8_t rk[AES_RKSIZE];
 
@@ -376,7 +376,7 @@ void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output,
   encrypt_ecb(AES_NR, rk, input, output);
 }
 
-void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length)
+void AES_ECB_decrypt_buffer(const uint8_t* input, const uint8_t* key, uint8_t *output)
 {
   static uint8_t rk[AES_RKSIZE];
 
diff --git a/lib/aes_faster_c/wrapper.cpp b/lib/aes_faster_c/wrapper.cpp
index 01cd94f..d58ace8 100644
--- a/lib/aes_faster_c/wrapper.cpp
+++ b/lib/aes_faster_c/wrapper.cpp
@@ -12,7 +12,7 @@
 #endif
 
 
-void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length)
+void AES_ECB_encrypt_buffer(const uint8_t* input, const uint8_t* key, uint8_t *output)
 {
 	static aes_context ctx;
 	if(key!=0)
@@ -24,7 +24,7 @@ void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output,
 	assert(ret==0);
 	return ;
 }
-void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length)
+void AES_ECB_decrypt_buffer(const uint8_t* input, const uint8_t* key, uint8_t *output)
 {
 	static aes_context ctx;
 	if(key!=0)