From 49ff83922bf6125b217eb02f699143da2da192ea Mon Sep 17 00:00:00 2001
From: BrownBear2 <->
Date: Thu, 13 Feb 2014 21:53:20 +0100
Subject: [PATCH] added romix kdf and cfb for aes

---
 CMakeLists.txt            |  1 +
 include/fc/crypto/aes.hpp |  2 ++
 src/crypto/aes.cpp        | 47 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5b43894..7514473 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -132,6 +132,7 @@ set( fc_sources
      src/crypto/elliptic.cpp
      src/crypto/salsa20.cpp
      src/crypto/scrypt.cpp
+     src/crypto/romix.cpp
      src/network/tcp_socket.cpp
      src/network/udp_socket.cpp
      src/network/http/http_connection.cpp
diff --git a/include/fc/crypto/aes.hpp b/include/fc/crypto/aes.hpp
index 8d4d043..70fdc7c 100644
--- a/include/fc/crypto/aes.hpp
+++ b/include/fc/crypto/aes.hpp
@@ -41,6 +41,8 @@ namespace fc {
                     unsigned char *iv, unsigned char *ciphertext);
     int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
                     unsigned char *iv, unsigned char *plaintext);
+    int aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+                    unsigned char *iv, unsigned char *plaintext);
 
     std::vector<char> aes_encrypt( const fc::sha512& key, const std::vector<char>& plain_text  );
     std::vector<char> aes_decrypt( const fc::sha512& key, const std::vector<char>& cipher_text );
diff --git a/src/crypto/aes.cpp b/src/crypto/aes.cpp
index 72315f3..3f0933f 100644
--- a/src/crypto/aes.cpp
+++ b/src/crypto/aes.cpp
@@ -248,7 +248,54 @@ int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *ke
     return plaintext_len;
 }
 
+int aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+              unsigned char *iv, unsigned char *plaintext)
+{
+    evp_cipher_ctx ctx( EVP_CIPHER_CTX_new() );
+    int len = 0;
+    int plaintext_len = 0;
 
+    /* Create and initialise the context */
+    if(!ctx)
+    {
+        FC_THROW_EXCEPTION( exception, "error allocating evp cipher context",
+                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
+    }
+
+    /* Initialise the decryption operation. IMPORTANT - ensure you use a key
+    *    * and IV size appropriate for your cipher
+    *       * In this example we are using 256 bit AES (i.e. a 256 bit key). The
+    *          * IV size for *most* modes is the same as the block size. For AES this
+    *             * is 128 bits */
+    if(1 != EVP_DecryptInit_ex(ctx, EVP_aes_256_cfb128(), NULL, key, iv))
+    {
+        FC_THROW_EXCEPTION( exception, "error durring aes 256 cbc decrypt init",
+                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
+    }
+
+    /* Provide the message to be decrypted, and obtain the plaintext output.
+    *    * EVP_DecryptUpdate can be called multiple times if necessary
+    *       */
+    if(1 != EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len))
+    {
+        FC_THROW_EXCEPTION( exception, "error durring aes 256 cbc decrypt update",
+                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
+    }
+
+    plaintext_len = len;
+
+    /* Finalise the decryption. Further plaintext bytes may be written at
+    *    * this stage.
+    *       */
+    if(1 != EVP_DecryptFinal_ex(ctx, plaintext + len, &len))
+    {
+        FC_THROW_EXCEPTION( exception, "error durring aes 256 cbc decrypt final",
+                           ("s", ERR_error_string( ERR_get_error(), nullptr) ) );
+    }
+    plaintext_len += len;
+
+    return plaintext_len;
+}
 
 std::vector<char> aes_encrypt( const fc::sha512& key, const std::vector<char>& plain_text  )
 {