diff --git a/hash/hmac.cpp b/hash/hmac.cpp
index 5ec56544..94845c9a 100644
--- a/hash/hmac.cpp
+++ b/hash/hmac.cpp
@@ -32,14 +32,15 @@ static const uint8_t OFILL = 0x5C;
 
 
 //-----------------------------------------------------------------------------
-HMAC::HMAC (const uint8_t *restrict key, size_t len)
+template <class T>
+HMAC<T>::HMAC (const uint8_t *restrict key, size_t len)
 {
     CHECK (key);
 
     static_assert (sizeof (m_ikey) == sizeof (m_okey), "key padding must match");
 
     // If the key is larger than the blocklength, use the hash of the key
-    if (len > 64) {
+    if (len > T::BLOCK_SIZE) {
         m_hash.update (key, len);
         m_hash.finish ();
 
@@ -74,16 +75,18 @@ HMAC::HMAC (const uint8_t *restrict key, size_t len)
 
 
 //-----------------------------------------------------------------------------
+template <class T>
 void
-HMAC::update (const void *restrict data, size_t len)
+HMAC<T>::update (const void *restrict data, size_t len)
 {
     m_hash.update ((const uint8_t*)data, len);
 }
 
 
 //-----------------------------------------------------------------------------
+template <class T>
 void
-HMAC::finish (void)
+HMAC<T>::finish (void)
 {
     m_hash.finish ();
     auto d = m_hash.digest ();
@@ -96,8 +99,9 @@ HMAC::finish (void)
 
 
 //-----------------------------------------------------------------------------
+template <class T>
 void
-HMAC::reset (void)
+HMAC<T>::reset (void)
 {
     m_hash.reset ();
     m_hash.update (m_ikey.data (), m_ikey.size ());
@@ -105,8 +109,17 @@ HMAC::reset (void)
 
 
 //-----------------------------------------------------------------------------
-HMAC::digest_t
-HMAC::digest (void)
+template <class T>
+typename HMAC<T>::digest_t
+HMAC<T>::digest (void)
 {
     return m_hash.digest ();
 }
+
+
+//-----------------------------------------------------------------------------
+#include "md5.hpp"
+#include "sha1.hpp"
+
+template class HMAC<util::hash::MD5>;
+template class HMAC<util::hash::SHA1>;
diff --git a/hash/hmac.hpp b/hash/hmac.hpp
index e187acb4..ede1e758 100644
--- a/hash/hmac.hpp
+++ b/hash/hmac.hpp
@@ -20,13 +20,16 @@
 #ifndef __UTIL_HASH_HMAC_HPP
 #define __UTIL_HASH_HMAC_HPP
 
-#include "md5.hpp"
+#include <array>
+#include <cstdint>
+#include <cstdlib>
 
 namespace util { namespace hash {
+    template <class T>
     /// RFC 2104 key-hashing for message authentication
     class HMAC {
     public:
-        using digest_t = MD5::digest_t;
+        using digest_t = typename T::digest_t;
 
         HMAC (const uint8_t *key, size_t);
 
@@ -37,10 +40,10 @@ namespace util { namespace hash {
         digest_t digest (void);
 
     private:
-        std::array<uint8_t,64> m_ikey;
-        std::array<uint8_t,64> m_okey;
+        std::array<uint8_t,T::BLOCK_SIZE> m_ikey;
+        std::array<uint8_t,T::BLOCK_SIZE> m_okey;
 
-        MD5 m_hash;
+        T m_hash;
     };
 } }
 
diff --git a/hash/md5.hpp b/hash/md5.hpp
index 0d1ee238..885c49dc 100644
--- a/hash/md5.hpp
+++ b/hash/md5.hpp
@@ -29,6 +29,8 @@ namespace util {
         class MD5 {
             public:
                 typedef std::array<uint8_t,16> digest_t;
+                static const size_t BLOCK_SIZE  = 64;
+                static const size_t DIGEST_SIZE = 16;
 
             public:
                 MD5();
diff --git a/hash/sha1.hpp b/hash/sha1.hpp
index 424c5461..c9b229be 100644
--- a/hash/sha1.hpp
+++ b/hash/sha1.hpp
@@ -31,6 +31,8 @@ namespace util { namespace hash {
     class SHA1 {
     public:
         typedef std::array<uint8_t,20> digest_t;
+        static const size_t BLOCK_SIZE  = 64;
+        static const size_t DIGEST_SIZE = 20;
 
     public:
         SHA1();
diff --git a/test/hmac.cpp b/test/hmac.cpp
index fb478ed7..1468e12e 100644
--- a/test/hmac.cpp
+++ b/test/hmac.cpp
@@ -1,6 +1,9 @@
 #include "hash/hmac.hpp"
-#include "types.hpp"
+
 #include "debug.hpp"
+#include "hash/md5.hpp"
+#include "hash/sha1.hpp"
+#include "types.hpp"
 
 #include <cstring>
 #include <iostream>
@@ -17,26 +20,50 @@ to_vector (const char *str)
 }
 
 
+//-----------------------------------------------------------------------------
+template <class T>
+bool
+test_hmac (const std::vector<uint8_t> &key,
+           const std::vector<uint8_t> &dat,
+           const std::vector<uint8_t> &res)
+{
+    util::hash::HMAC<T> h (key.data (), key.size ());
+    h.update (dat.data (), dat.size ());
+    h.finish ();
+
+    auto ours = h.digest ();
+
+    return std::equal (ours.begin (), ours.end (), res.begin ());
+}
+
+
+typedef bool (*test_func) (const std::vector<uint8_t>&,
+                           const std::vector<uint8_t>&,
+                           const std::vector<uint8_t>&);
+
 //-----------------------------------------------------------------------------
 static const struct {
     std::vector<uint8_t> key;
     std::vector<uint8_t> dat;
-    HMAC::digest_t res;
+    std::vector<uint8_t> res;
+    test_func            fun;
 } TESTS[] = {
     // RFC 2104 test data, MD5
     {
         { 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
           0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b  },
         { 'H', 'i', ' ', 'T', 'h', 'e', 'r', 'e' },
-        { { 0x92, 0x94, 0x72, 0x7a, 0x36, 0x38, 0xbb, 0x1c,
-            0x13, 0xf4, 0x8e, 0xf8, 0x15, 0x8b, 0xfc, 0x9d } }
+        { 0x92, 0x94, 0x72, 0x7a, 0x36, 0x38, 0xbb, 0x1c,
+          0x13, 0xf4, 0x8e, 0xf8, 0x15, 0x8b, 0xfc, 0x9d },
+        &test_hmac<util::hash::MD5>
     },
 
     {
         to_vector ("Jefe"),
         to_vector ("what do ya want for nothing?"),
-        { { 0x75, 0x0c, 0x78, 0x3e, 0x6a, 0xb0, 0xb5, 0x03,
-            0xea, 0xa8, 0x6e, 0x31, 0x0a, 0x5d, 0xb7, 0x38 } }
+        { 0x75, 0x0c, 0x78, 0x3e, 0x6a, 0xb0, 0xb5, 0x03,
+          0xea, 0xa8, 0x6e, 0x31, 0x0a, 0x5d, 0xb7, 0x38 },
+        &test_hmac<util::hash::MD5>
     },
 
     {
@@ -49,8 +76,9 @@ static const struct {
           0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD,
           0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD, 0xDD,
           0xDD, 0xDD },
-        { { 0x56, 0xbe, 0x34, 0x52, 0x1d, 0x14, 0x4c, 0x88,
-            0xdb, 0xb8, 0xc7, 0x33, 0xf0, 0xe8, 0xb3, 0xf6 } }
+        { 0x56, 0xbe, 0x34, 0x52, 0x1d, 0x14, 0x4c, 0x88,
+          0xdb, 0xb8, 0xc7, 0x33, 0xf0, 0xe8, 0xb3, 0xf6 },
+        &test_hmac<util::hash::MD5>
     },
 
     // RFC 2202 test data, MD5
@@ -66,16 +94,18 @@ static const struct {
           0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD,
           0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD, 0xCD,
           0xCD, 0xCD },
-        { { 0x69, 0x7e, 0xaf, 0x0a, 0xca, 0x3a, 0x3a, 0xea,
-            0x3a, 0x75, 0x16, 0x47, 0x46, 0xff, 0xaa, 0x79 } }
+        { 0x69, 0x7e, 0xaf, 0x0a, 0xca, 0x3a, 0x3a, 0xea,
+          0x3a, 0x75, 0x16, 0x47, 0x46, 0xff, 0xaa, 0x79 },
+        &test_hmac<util::hash::MD5>
     },
 
     {
         { 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
           0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c },
         to_vector ("Test With Truncation"),
-        { { 0x56, 0x46, 0x1e, 0xf2, 0x34, 0x2e, 0xdc, 0x00,
-            0xf9, 0xba, 0xb9, 0x95, 0x69, 0x0e, 0xfd, 0x4c } }
+        { 0x56, 0x46, 0x1e, 0xf2, 0x34, 0x2e, 0xdc, 0x00,
+          0xf9, 0xba, 0xb9, 0x95, 0x69, 0x0e, 0xfd, 0x4c },
+        &test_hmac<util::hash::MD5>
         // digest-96: 0x56461ef2342edc00f9bab995
     },
 
@@ -91,8 +121,9 @@ static const struct {
           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa },
         to_vector ("Test Using Larger Than Block-Size Key - Hash Key First"),
-        { { 0x6b, 0x1a, 0xb7, 0xfe, 0x4b, 0xd7, 0xbf, 0x8f,
-            0x0b, 0x62, 0xe6, 0xce, 0x61, 0xb9, 0xd0, 0xcd } }
+        { 0x6b, 0x1a, 0xb7, 0xfe, 0x4b, 0xd7, 0xbf, 0x8f,
+          0x0b, 0x62, 0xe6, 0xce, 0x61, 0xb9, 0xd0, 0xcd },
+        &test_hmac<util::hash::MD5>
     },
 
     {
@@ -107,9 +138,131 @@ static const struct {
           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
           0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa },
         to_vector ("Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data"),
-        { { 0x6f, 0x63, 0x0f, 0xad, 0x67, 0xcd, 0xa0, 0xee,
-            0x1f, 0xb1, 0xf5, 0x62, 0xdb, 0x3a, 0xa5, 0x3e } }
-    }
+        { 0x6f, 0x63, 0x0f, 0xad, 0x67, 0xcd, 0xa0, 0xee,
+          0x1f, 0xb1, 0xf5, 0x62, 0xdb, 0x3a, 0xa5, 0x3e },
+        &test_hmac<util::hash::MD5>
+    },
+
+    // RFC 2202 test data, SHA1
+    {
+        { 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+          0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
+          0x0b, 0x0b, 0x0b, 0x0b },
+        to_vector ("Hi There"),
+        { 0xb6, 0x17, 0x31, 0x86, 0x55, 0x05, 0x72, 0x64,
+          0xe2, 0x8b, 0xc0, 0xb6, 0xfb, 0x37, 0x8c, 0x8e,
+          0xf1, 0x46, 0xbe, 0x00 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        to_vector ("Jefe"),
+        to_vector ("what do ya want for nothing?"),
+        { 0xef, 0xfc, 0xdf, 0x6a, 0xe5, 0xeb, 0x2f, 0xa2,
+          0xd2, 0x74, 0x16, 0xd5, 0xf1, 0x84, 0xdf, 0x9c,
+          0x25, 0x9a, 0x7c, 0x79 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa },
+        { 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd, 0xdd,
+          0xdd, 0xdd },
+        { 0x12, 0x5d, 0x73, 0x42, 0xb9, 0xac, 0x11, 0xcd,
+          0x91, 0xa3, 0x9a, 0xf4, 0x8a, 0xa1, 0x7b, 0x4f,
+          0x63, 0xf1, 0x75, 0xd3 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+          0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10,
+          0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+          0x19 },
+        { 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd, 0xcd,
+          0xcd, 0xcd },
+        { 0x4c, 0x90, 0x07, 0xf4, 0x02, 0x62, 0x50, 0xc6,
+          0xbc, 0x84, 0x14, 0xf9, 0xbf, 0x50, 0xc8, 0x6c,
+          0x2d, 0x72, 0x35, 0xda },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+          0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
+          0x0c, 0x0c, 0x0c, 0x0c },
+        to_vector ("Test With Truncation"),
+        { 0x4c, 0x1a, 0x03, 0x42, 0x4b, 0x55, 0xe0, 0x7f,
+          0xe7, 0xf2, 0x7b, 0xe1, 0xd5, 0x8b, 0xb9, 0x32,
+          0x4a, 0x9a, 0x5a, 0x04 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa },
+        to_vector ("Test Using Larger Than Block-Size Key - Hash Key First"),
+        { 0xaa, 0x4a, 0xe5, 0xe1, 0x52, 0x72, 0xd0, 0x0e,
+          0x95, 0x70, 0x56, 0x37, 0xce, 0x8a, 0x3b, 0x55,
+          0xed, 0x40, 0x21, 0x12 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa },
+        to_vector ("Test Using Larger Than Block-Size Key - Hash Key First"),
+        { 0xaa, 0x4a, 0xe5, 0xe1, 0x52, 0x72, 0xd0, 0x0e,
+          0x95, 0x70, 0x56, 0x37, 0xce, 0x8a, 0x3b, 0x55,
+          0xed, 0x40, 0x21, 0x12 },
+        &test_hmac<util::hash::SHA1>
+    },
+
+    {
+        { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
+          0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa },
+        to_vector ("Test Using Larger Than Block-Size Key and Larger Than One Block-Size Data"),
+        { 0xe8, 0xe9, 0x9d, 0x0f, 0x45, 0x23, 0x7d, 0x78,
+          0x6d, 0x6b, 0xba, 0xa7, 0x96, 0x5c, 0x78, 0x08,
+          0xbb, 0xff, 0x1a, 0x91 },
+        &test_hmac<util::hash::SHA1>
+    },
 };
 
 
@@ -121,11 +274,8 @@ main (int, char**)
     for (const auto &t: TESTS) {
         std::cerr << i++ << ": " << t.key.size () << ", " << t.dat.size () << '\n';
 
-        util::hash::HMAC h (t.key.data (), t.key.size ());
-        h.update (t.dat.data (), t.dat.size ());
-        h.finish ();
 
-        if (h.digest () != t.res)
+        if (!t.fun (t.key, t.dat, t.res))
             return EXIT_FAILURE;
     }