From 59a1eb973b1d15b4d037e0658ed33ad937d21efc Mon Sep 17 00:00:00 2001
From: Yehuda Sadeh <yehuda@hq.newdream.net>
Date: Wed, 19 Aug 2009 15:36:16 -0700
Subject: [PATCH] auth: aes decrypt

---
 src/auth/CryptoTools.cc | 65 ++++++++++++++++++++++++++++++-----------
 src/auth/CryptoTools.h  | 35 ++++++++++++++++++++++
 2 files changed, 83 insertions(+), 17 deletions(-)
 create mode 100644 src/auth/CryptoTools.h

diff --git a/src/auth/CryptoTools.cc b/src/auth/CryptoTools.cc
index a8ca967e87d3c..2d1fc3a2f4f58 100644
--- a/src/auth/CryptoTools.cc
+++ b/src/auth/CryptoTools.cc
@@ -12,6 +12,7 @@
  */
 
 #include "AuthTypes.h"
+#include "CryptoTools.h"
 #include "openssl/evp.h"
 #include "openssl/aes.h"
 
@@ -19,12 +20,6 @@
 #define CEPH_CRYPTO_AES      0x1
 
 
-class CryptoHandler {
-public:
-  virtual bool encrypt(EntitySecret& secret, bufferlist& in, bufferlist& out) = 0;
-  virtual bool decrypt(EntitySecret& secret, bufferlist& in, bufferlist& out) = 0;
-};
-
 class CryptoStupid : public CryptoHandler {
 public:
   CryptoStupid() {}
@@ -67,11 +62,12 @@ public:
   bool decrypt(EntitySecret& secret, bufferlist& in, bufferlist& out);
 };
 
-static const char *aes_iv = "cephsageyudagreg";
+static const unsigned char *aes_iv = (const unsigned char *)"cephsageyudagreg";
 
 bool CryptoAES::encrypt(EntitySecret& secret, bufferlist& in, bufferlist& out)
 {
   bufferlist sec_bl = secret.get_secret();
+  const unsigned char *key = (const unsigned char *)sec_bl.c_str();
   int in_len = in.length();
   const unsigned char *in_buf = (const unsigned char *)in.c_str();
   int outlen = (in_len + AES_BLOCK_SIZE) & ~(AES_BLOCK_SIZE -1);
@@ -81,10 +77,9 @@ bool CryptoAES::encrypt(EntitySecret& secret, bufferlist& in, bufferlist& out)
   if (sec_bl.length() < AES_KEY_LEN)
     return false;
 
-  const char *key = sec_bl.c_str();
   EVP_CIPHER_CTX ctx;
   EVP_CIPHER_CTX_init(&ctx);
-  EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, (const unsigned char *)key, (const unsigned char *)aes_iv);
+  EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key, aes_iv);
 
   unsigned char *outbuf = (unsigned char *)outptr.c_str();
 
@@ -102,18 +97,50 @@ bool CryptoAES::encrypt(EntitySecret& secret, bufferlist& in, bufferlist& out)
 
 bool CryptoAES::decrypt(EntitySecret& secret, bufferlist& in, bufferlist& out)
 {
-  return false;
-}
+  bufferlist sec_bl = secret.get_secret();
+  const unsigned char *key = (const unsigned char *)sec_bl.c_str();
 
-static CryptoStupid crypto_stupid;
-static CryptoAES crypto_aes;
+  int in_len = in.length();
+  int dec_len = 0;
+  int last_dec_len = 0;
 
+  bufferptr outptr(in_len);
+  unsigned char *dec_data = (unsigned char *)outptr.c_str();
+  bool result = false;
+
+  EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
+  EVP_CIPHER_CTX_init(ctx);
+
+  int res = EVP_DecryptInit_ex(ctx, EVP_aes_128_cbc(), NULL, key, aes_iv);
+  if (res == 1) {
+    res = EVP_DecryptUpdate(ctx, dec_data,
+           &dec_len, (const unsigned char *)in.c_str(), in.length());
+
+    if (res == 1) {
+      EVP_DecryptFinal_ex(ctx,
+            dec_data + dec_len,
+            &last_dec_len);
+
+            dec_len += last_dec_len;
+      outptr.set_length(dec_len);
+      out.append(outptr);
+      dout(0) << "decrypted size: %d" << dec_len << dendl;
+
+      result = true;
+    } else {
+            dout(0) << "EVP_DecryptUpdate error" << dendl;
+    }
+  } else {
+    dout(0) << "EVP_DecryptInit_ex error" << dendl;
+  }
 
-class CryptoManager {
-public:
-  CryptoHandler *get_crypto(int type);
-};
+  EVP_CIPHER_CTX_free(ctx);
+  EVP_cleanup();
+  return result;
+}
 
+static CryptoStupid crypto_stupid;
+static CryptoAES crypto_aes;
 
 CryptoHandler *CryptoManager::get_crypto(int type)
 {
@@ -126,3 +153,7 @@ CryptoHandler *CryptoManager::get_crypto(int type)
       return NULL;
   }
 }
+
+CryptoManager ceph_crypto_mgr;
+
+
diff --git a/src/auth/CryptoTools.h b/src/auth/CryptoTools.h
new file mode 100644
index 0000000000000..b1860aac26c40
--- /dev/null
+++ b/src/auth/CryptoTools.h
@@ -0,0 +1,35 @@
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2009 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef __CRYPTOTOOLS_H
+#define __CRYPTOTOOLS_H
+
+#define CEPH_CRYPTO_STUPID   0x0
+#define CEPH_CRYPTO_AES      0x1
+
+
+class CryptoHandler {
+public:
+  virtual bool encrypt(EntitySecret& secret, bufferlist& in, bufferlist& out) = 0;
+  virtual bool decrypt(EntitySecret& secret, bufferlist& in, bufferlist& out) = 0;
+};
+
+class CryptoManager {
+public:
+  CryptoHandler *get_crypto(int type);
+};
+
+extern CryptoManager ceph_crypto_mgr;
+
+
+#endif
-- 
2.39.5