2 files changed, 8 insertions, 4 deletions
diff --git a/src/mac/hmac/hmac.cpp b/src/mac/hmac/hmac.cpp
index 06923138a..fc35e26ea 100644
--- a/src/mac/hmac/hmac.cpp
+++ b/src/mac/hmac/hmac.cpp
@@ -84,10 +84,7 @@ MessageAuthenticationCode* HMAC::clone() const
 /*
 * HMAC Constructor
 */
-HMAC::HMAC(HashFunction* hash_in) :
-   MessageAuthenticationCode(hash_in->output_length(),
-                             0, 2*hash_in->hash_block_size()),
-   hash(hash_in)
+HMAC::HMAC(HashFunction* hash_in) : hash(hash_in)
    {
    if(hash->hash_block_size() == 0)
       throw Invalid_Argument("HMAC cannot be used with " + hash->name());
diff --git a/src/mac/hmac/hmac.h b/src/mac/hmac/hmac.h
index 33af62f6a..b76a058f4 100644
--- a/src/mac/hmac/hmac.h
+++ b/src/mac/hmac/hmac.h
@@ -23,6 +23,13 @@ class BOTAN_DLL HMAC : public MessageAuthenticationCode
       std::string name() const;
       MessageAuthenticationCode* clone() const;
 
+      size_t output_length() const { return hash->output_length(); }
+
+      Key_Length_Specification key_spec() const
+         {
+         return Key_Length_Specification(0, 2*hash->hash_block_size());
+         }
+
       /**
       * @param hash the hash to use for HMACing
       */