working on rc4

jni/shadowsocks/encrypt.c

@@ -113,8 +113,9 @@ static void mergesort(uint8_t array[], int length)
 
 void encrypt(char *buf, int len) {
     if (_method == RC4_ENC) {
+        int outlen;
         unsigned char mybuf[BUF_SIZE];
-        RC4(&rc4_key, len, (unsigned char *) buf, mybuf);
+        EVP_CipherUpdate(&ctx, mybuf, &outlen, (unsigned char*)buf, len);
         memcpy(buf, mybuf, len);
     } else {
         char *end = buf + len;
@@ -127,8 +128,9 @@ void encrypt(char *buf, int len) {
 
 void decrypt(char *buf, int len) {
     if (_method == RC4_ENC) {
+        int outlen;
         unsigned char mybuf[BUF_SIZE];
-        RC4(&rc4_key, len, (unsigned char *) buf, mybuf);
+        EVP_CipherUpdate(&ctx, mybuf, &outlen, (unsigned char*) buf, len);
         memcpy(buf, mybuf, len);
     } else {
         char *end = buf + len;
@@ -154,13 +156,24 @@ int recv_decrypt(int sock, char *buf, int len, int flags) {
     return result;
 }
 
-void get_table(const char* key) {
+void get_table(const char* pass) {
     if (_method == RC4_ENC) {
-        RC4_set_key(&rc4_key, strlen(key), (unsigned char *) key);
+        unsigned char key[EVP_MAX_KEY_LENGTH];
+        unsigned char iv[EVP_MAX_IV_LENGTH];
+        int key_len = EVP_BytesToKey(EVP_rc4(), EVP_md5(), NULL, (unsigned char*) pass, 
+                strlen(pass), 1, key, iv);
+        EVP_CIPHER_CTX_init(&ctx);
+        EVP_CipherInit_ex(&ctx, EVP_rc4(), NULL, NULL, NULL, 1);
+        if (!EVP_CIPHER_CTX_set_key_length(&ctx, key_len)) {
+            LOGE("Invalid key length: %d", key_len);
+            EVP_CIPHER_CTX_cleanup(&ctx);
+            exit(EXIT_FAILURE);
+        }
+        EVP_CipherInit_ex(&ctx, NULL, NULL, key, iv, 1);
     } else {
         uint8_t *table = encrypt_table;
-        uint8_t *tmp_hash = MD5((const uint8_t*)key, strlen(key), NULL);
-        _a = htole64(*(uint64_t *)tmp_hash);
+        uint8_t *tmp_hash = MD5((unsigned char *) pass, strlen(pass), NULL);
+        _a = htole64(*(uint64_t *) tmp_hash);
         uint32_t i;
 
         for(i = 0; i < 256; ++i) {

jni/shadowsocks/encrypt.h

@@ -5,7 +5,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <openssl/md5.h>
-#include <openssl/rc4.h>
+#include <openssl/evp.h>
 #include <endian.h>
 
 #define BUF_SIZE 4096
@@ -15,7 +15,7 @@
 
 unsigned char encrypt_table[256];
 unsigned char decrypt_table[256];
-RC4_KEY rc4_key;
+EVP_CIPHER_CTX ctx;
 
 void get_table(const char* key);
 void encrypt(char *buf, int len);