Merge #1301 Add AES key wrap with padding

3 files changed, 11 insertions, 74 deletions

diff --git a/src/lib/misc/rfc3394/info.txt b/src/lib/misc/rfc3394/info.txt
index ac56ee833..075834219 100644
--- a/src/lib/misc/rfc3394/info.txt
+++ b/src/lib/misc/rfc3394/info.txt
@@ -4,4 +4,5 @@ RFC3394_KEYWRAP -> 20131128
 
 <requires>
 aes
+nist_keywrap
 </requires>
diff --git a/src/lib/misc/rfc3394/rfc3394.cpp b/src/lib/misc/rfc3394/rfc3394.cpp
index 3bb792723..8e69933c7 100644
--- a/src/lib/misc/rfc3394/rfc3394.cpp
+++ b/src/lib/misc/rfc3394/rfc3394.cpp
@@ -6,18 +6,14 @@
 */
 
 #include <botan/rfc3394.h>
+#include <botan/nist_keywrap.h>
 #include <botan/block_cipher.h>
-#include <botan/loadstor.h>
-#include <botan/exceptn.h>
 
 namespace Botan {
 
 secure_vector<uint8_t> rfc3394_keywrap(const secure_vector<uint8_t>& key,
-                                    const SymmetricKey& kek)
+                                       const SymmetricKey& kek)
    {
-   if(key.size() % 8 != 0)
-      throw Invalid_Argument("Bad input key size for NIST key wrap");
-
    if(kek.size() != 16 && kek.size() != 24 && kek.size() != 32)
       throw Invalid_Argument("Bad KEK length " + std::to_string(kek.size()) + " for NIST key wrap");
 
@@ -25,40 +21,12 @@ secure_vector<uint8_t> rfc3394_keywrap(const secure_vector<uint8_t>& key,
    std::unique_ptr<BlockCipher> aes(BlockCipher::create_or_throw(cipher_name));
    aes->set_key(kek);
 
-   const size_t n = key.size() / 8;
-
-   secure_vector<uint8_t> R((n + 1) * 8);
-   secure_vector<uint8_t> A(16);
-
-   for(size_t i = 0; i != 8; ++i)
-      A[i] = 0xA6;
-
-   copy_mem(&R[8], key.data(), key.size());
-
-   for(size_t j = 0; j <= 5; ++j)
-      {
-      for(size_t i = 1; i <= n; ++i)
-         {
-         const uint32_t t = static_cast<uint32_t>((n * j) + i);
-
-         copy_mem(&A[8], &R[8*i], 8);
-
-         aes->encrypt(A.data());
-         copy_mem(&R[8*i], &A[8], 8);
-
-         uint8_t t_buf[4] = { 0 };
-         store_be(t, t_buf);
-         xor_buf(&A[4], t_buf, 4);
-         }
-      }
-
-   copy_mem(R.data(), A.data(), 8);
-
-   return R;
+   std::vector<uint8_t> wrapped = nist_key_wrap(key.data(), key.size(), *aes);
+   return secure_vector<uint8_t>(wrapped.begin(), wrapped.end());
    }
 
 secure_vector<uint8_t> rfc3394_keyunwrap(const secure_vector<uint8_t>& key,
-                                      const SymmetricKey& kek)
+                                         const SymmetricKey& kek)
    {
    if(key.size() < 16 || key.size() % 8 != 0)
       throw Invalid_Argument("Bad input key size for NIST key unwrap");
@@ -70,39 +38,7 @@ secure_vector<uint8_t> rfc3394_keyunwrap(const secure_vector<uint8_t>& key,
    std::unique_ptr<BlockCipher> aes(BlockCipher::create_or_throw(cipher_name));
    aes->set_key(kek);
 
-   const size_t n = (key.size() - 8) / 8;
-
-   secure_vector<uint8_t> R(n * 8);
-   secure_vector<uint8_t> A(16);
-
-   for(size_t i = 0; i != 8; ++i)
-      A[i] = key[i];
-
-   copy_mem(R.data(), &key[8], key.size() - 8);
-
-   for(size_t j = 0; j <= 5; ++j)
-      {
-      for(size_t i = n; i != 0; --i)
-         {
-         const uint32_t t = static_cast<uint32_t>((5 - j) * n + i);
-
-         uint8_t t_buf[4] = { 0 };
-         store_be(t, t_buf);
-
-         xor_buf(&A[4], t_buf, 4);
-
-         copy_mem(&A[8], &R[8*(i-1)], 8);
-
-         aes->decrypt(A.data());
-
-         copy_mem(&R[8*(i-1)], &A[8], 8);
-         }
-      }
-
-   if(load_be<uint64_t>(A.data(), 0) != 0xA6A6A6A6A6A6A6A6)
-      throw Integrity_Failure("NIST key unwrap failed");
-
-   return R;
+   return nist_key_unwrap(key.data(), key.size(), *aes);
    }
 
 }
diff --git a/src/lib/misc/rfc3394/rfc3394.h b/src/lib/misc/rfc3394/rfc3394.h
index 77e602fda..9cfcfaaf6 100644
--- a/src/lib/misc/rfc3394/rfc3394.h
+++ b/src/lib/misc/rfc3394/rfc3394.h
@@ -5,8 +5,8 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#ifndef BOTAN_AES_KEY_WRAP_H_
-#define BOTAN_AES_KEY_WRAP_H_
+#ifndef BOTAN_RFC3394_H_
+#define BOTAN_RFC3394_H_
 
 #include <botan/symkey.h>
 
@@ -21,7 +21,7 @@ namespace Botan {
 * @return key encrypted under kek
 */
 secure_vector<uint8_t> BOTAN_PUBLIC_API(2,0) rfc3394_keywrap(const secure_vector<uint8_t>& key,
-                                              const SymmetricKey& kek);
+                                                             const SymmetricKey& kek);
 
 /**
 * Decrypt a key under a key encryption key using the algorithm
@@ -32,7 +32,7 @@ secure_vector<uint8_t> BOTAN_PUBLIC_API(2,0) rfc3394_keywrap(const secure_vector
 * @return key decrypted under kek
 */
 secure_vector<uint8_t> BOTAN_PUBLIC_API(2,0) rfc3394_keyunwrap(const secure_vector<uint8_t>& key,
-                                                const SymmetricKey& kek);
+                                                               const SymmetricKey& kek);
 
 }