Add a simple update_be to BufferedComputation that takes an integer

and writes the bytes to the stream in big-endian order. Use it in
KDF2, MGF1, and FPE.

2 files changed, 3 insertions, 6 deletions

diff --git a/src/kdf/kdf2/kdf2.cpp b/src/kdf/kdf2/kdf2.cpp
index b10077e35..51b9e41ea 100644
--- a/src/kdf/kdf2/kdf2.cpp
+++ b/src/kdf/kdf2/kdf2.cpp
@@ -6,7 +6,6 @@
 */
 
 #include <botan/kdf2.h>
-#include <botan/get_byte.h>
 
 namespace Botan {
 
@@ -23,9 +22,9 @@ SecureVector<byte> KDF2::derive(size_t out_len,
    while(out_len && counter)
       {
       hash->update(secret, secret_len);
-      for(size_t i = 0; i != 4; ++i)
-         hash->update(get_byte(i, counter));
+      hash->update_be(counter);
       hash->update(P, P_len);
+
       SecureVector<byte> hash_result = hash->final();
 
       size_t added = std::min(hash_result.size(), out_len);
diff --git a/src/kdf/mgf1/mgf1.cpp b/src/kdf/mgf1/mgf1.cpp
index 6dc028bad..7d949c2b8 100644
--- a/src/kdf/mgf1/mgf1.cpp
+++ b/src/kdf/mgf1/mgf1.cpp
@@ -6,7 +6,6 @@
 */
 
 #include <botan/mgf1.h>
-#include <botan/get_byte.h>
 #include <botan/exceptn.h>
 #include <botan/internal/xor_buf.h>
 #include <algorithm>
@@ -25,8 +24,7 @@ void MGF1::mask(const byte in[], size_t in_len, byte out[],
    while(out_len)
       {
       hash->update(in, in_len);
-      for(size_t i = 0; i != 4; ++i)
-         hash->update(get_byte(i, counter));
+      hash->update_be(counter);
       SecureVector<byte> buffer = hash->final();
 
       size_t xored = std::min<size_t>(buffer.size(), out_len);