set iv to fixed length of 16byte in kd

3 files changed, 7 insertions, 6 deletions

diff --git a/keyDerivation.cpp b/keyDerivation.cpp
index 406e877..5e5068a 100644
--- a/keyDerivation.cpp
+++ b/keyDerivation.cpp
@@ -133,9 +133,7 @@ void KeyDerivation::generate(satp_prf_label label, seq_nr_t seq_nr, Buffer& key,
   if( err ) 
     cLog.msg(Log::PRIO_ERR) << "KeyDerivation::generate: Failed to reset cipher: " << gpg_strerror( err );
 
-  iv.clearHighBit(129);  
-  
-  err = gcry_cipher_setiv( cipher_ , iv.getBuf().getBuf(), iv.getBuf().getLength());
+  err = gcry_cipher_setiv( cipher_ , iv.getBuf(16).getBuf(), iv.getBuf().getLength());
   if( err )
     cLog.msg(Log::PRIO_ERR) << "KeyDerivation::generate: Failed to set IV: " << gpg_strerror( err );
 
diff --git a/mpi.cpp b/mpi.cpp
index b8a4b6c..6a94f3e 100644
--- a/mpi.cpp
+++ b/mpi.cpp
@@ -127,14 +127,17 @@ void Mpi::clearHighBit(u_int32_t n)
   gcry_mpi_clear_highbit( val_, n );
 }
 
-Buffer Mpi::getBuf() const
+Buffer Mpi::getBuf(u_int32_t min_len) const
 {
   u_int32_t len = 0, written = 0;
   len = gcry_mpi_get_nbits( val_ );
 
   Buffer res(static_cast<u_int32_t>(len/8)+1);
 
-  gcry_mpi_print( GCRYMPI_FMT_STD, res, len, &written, val_ );
+  if(res.getLength() < min_len)
+    res.resizeBack(min_len);
+
+  gcry_mpi_print( GCRYMPI_FMT_STD, res, res.getLength(), &written, val_ );
   return res;
 }
 
diff --git a/mpi.h b/mpi.h
index b423d7c..6121d9c 100644
--- a/mpi.h
+++ b/mpi.h
@@ -55,7 +55,7 @@ public:
   void rShift(u_int8_t n);            // LSB on the right side!
   Mpi mul2exp(u_int32_t e) const;     // value * 2^e
   void clearHighBit(u_int32_t n);
-  Buffer getBuf() const;
+  Buffer getBuf(u_int32_t min_len=0) const;
   u_int32_t getLen() const;
  
 protected: