1 files changed, 62 insertions, 0 deletions
diff --git a/src/pbkdf/pbkdf2/pbkdf2.cpp b/src/pbkdf/pbkdf2/pbkdf2.cpp
new file mode 100644
index 000000000..e88a5749a
--- /dev/null
+++ b/src/pbkdf/pbkdf2/pbkdf2.cpp
@@ -0,0 +1,62 @@
+/*
+* PBKDF2
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/pbkdf2.h>
+#include <botan/get_byte.h>
+#include <botan/internal/xor_buf.h>
+
+namespace Botan {
+
+/*
+* Return a PKCS #5 PBKDF2 derived key
+*/
+OctetString PKCS5_PBKDF2::derive_key(u32bit key_len,
+                                     const std::string& passphrase,
+                                     const byte salt[], u32bit salt_size,
+                                     u32bit iterations) const
+   {
+   if(iterations == 0)
+      throw Invalid_Argument("PKCS#5 PBKDF2: Invalid iteration count");
+
+   if(passphrase.length() == 0)
+      throw Invalid_Argument("PKCS#5 PBKDF2: Empty passphrase is invalid");
+
+   mac->set_key(reinterpret_cast<const byte*>(passphrase.data()),
+                passphrase.length());
+
+   SecureVector<byte> key(key_len);
+
+   byte* T = key.begin();
+
+   u32bit counter = 1;
+   while(key_len)
+      {
+      u32bit T_size = std::min(mac->OUTPUT_LENGTH, key_len);
+      SecureVector<byte> U(mac->OUTPUT_LENGTH);
+
+      mac->update(salt, salt_size);
+      for(u32bit j = 0; j != 4; ++j)
+         mac->update(get_byte(j, counter));
+      mac->final(U);
+      xor_buf(T, U, T_size);
+
+      for(u32bit j = 1; j != iterations; ++j)
+         {
+         mac->update(U);
+         mac->final(U);
+         xor_buf(T, U, T_size);
+         }
+
+      key_len -= T_size;
+      T += T_size;
+      ++counter;
+      }
+
+   return key;
+   }
+
+}