1 files changed, 157 insertions, 0 deletions
diff --git a/src/lib/kdf/sp800_108/sp800_108.cpp b/src/lib/kdf/sp800_108/sp800_108.cpp
new file mode 100644
index 000000000..873db814c
--- /dev/null
+++ b/src/lib/kdf/sp800_108/sp800_108.cpp
@@ -0,0 +1,157 @@
+/*
+* KDFs defined in NIST SP 800-108
+* (C) 2016 Kai Michaelis
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/sp800_108.h>
+#include <botan/hmac.h>
+
+namespace Botan {
+
+SP800_108_Counter* SP800_108_Counter::make(const Spec& spec)
+   {
+   if(auto mac = MessageAuthenticationCode::create(spec.arg(0)))
+      return new SP800_108_Counter(mac.release());
+
+   if(auto mac = MessageAuthenticationCode::create("HMAC(" + spec.arg(0) + ")"))
+      return new SP800_108_Counter(mac.release());
+
+   return nullptr;
+   }
+
+size_t SP800_108_Counter::kdf(byte key[], size_t key_len,
+                              const byte secret[], size_t secret_len,
+                              const byte salt[], size_t salt_len) const
+   {
+      const std::size_t prf_len =  m_prf->output_length();
+      byte *p = key;
+      uint32_t counter = 1;
+      secure_vector<byte> tmp;
+
+      m_prf->set_key(secret, secret_len);
+
+      while(p < key + key_len && counter != 0)
+         {
+         const std::size_t to_copy = std::min< std::size_t >(key + key_len - p, prf_len);
+         byte be_cnt[4] = { 0 };
+
+         store_be(counter, be_cnt);
+
+         m_prf->update(be_cnt,4);
+         m_prf->update(salt, salt_len);
+         m_prf->final(tmp);
+
+         std::move(tmp.begin(), tmp.begin() + to_copy, p);
+         ++counter;
+
+         if (counter == 0)
+            throw Invalid_Argument("Can't process more than 4GB");
+
+         p += to_copy;
+         }
+
+   return key_len;
+   }
+
+SP800_108_Feedback* SP800_108_Feedback::make(const Spec& spec)
+   {
+   if(auto mac = MessageAuthenticationCode::create(spec.arg(0)))
+      return new SP800_108_Feedback(mac.release());
+
+   if(auto mac = MessageAuthenticationCode::create("HMAC(" + spec.arg(0) + ")"))
+      return new SP800_108_Feedback(mac.release());
+
+   return nullptr;
+   }
+
+size_t SP800_108_Feedback::kdf(byte key[], size_t key_len,
+                               const byte secret[], size_t secret_len,
+                               const byte salt[], size_t salt_len) const
+   {
+      const std::size_t prf_len =  m_prf->output_length();
+      const std::size_t iv_len = (salt_len >= prf_len ? prf_len : 0);
+
+      byte *p = key;
+      uint32_t counter = 1;
+      secure_vector< byte > prev(salt, salt + iv_len);
+      secure_vector< byte > ctx(salt + iv_len, salt + salt_len);
+
+      m_prf->set_key(secret, secret_len);
+
+      while(p < key + key_len && counter != 0)
+         {
+         const std::size_t to_copy = std::min< std::size_t >(key + key_len - p, prf_len);
+         byte be_cnt[4] = { 0 };
+
+         store_be(counter, be_cnt);
+
+         m_prf->update(prev);
+         m_prf->update(be_cnt,4);
+         m_prf->update(ctx);
+         m_prf->final(prev);
+
+         std::copy(prev.begin(), prev.begin() + to_copy, p);
+         ++counter;
+
+         if (counter == 0)
+            throw Invalid_Argument("Can't process more than 4GB");
+
+         p += to_copy;
+         }
+
+   return key_len;
+   }
+
+SP800_108_Pipeline* SP800_108_Pipeline::make(const Spec& spec)
+   {
+   if(auto mac = MessageAuthenticationCode::create(spec.arg(0)))
+      return new SP800_108_Pipeline(mac.release());
+
+   if(auto mac = MessageAuthenticationCode::create("HMAC(" + spec.arg(0) + ")"))
+      return new SP800_108_Pipeline(mac.release());
+
+   return nullptr;
+   }
+
+size_t SP800_108_Pipeline::kdf(byte key[], size_t key_len,
+                    const byte secret[], size_t secret_len,
+                    const byte salt[], size_t salt_len) const
+   {
+      const std::size_t prf_len =  m_prf->output_length();
+      byte *p = key;
+      uint32_t counter = 1;
+      secure_vector<byte> ai(salt, salt + salt_len), ki;
+
+      m_prf->set_key(secret,secret_len);
+
+      while(p < key + key_len && counter != 0)
+         {
+         // A(i)
+         m_prf->update(ai);
+         m_prf->final(ai);
+
+         // K(i)
+         const std::size_t to_copy = std::min< std::size_t >(key + key_len - p, prf_len);
+         byte be_cnt[4] = { 0 };
+
+         store_be(counter, be_cnt);
+
+         m_prf->update(ai);
+         m_prf->update(be_cnt,4);
+         m_prf->update(salt, salt_len);
+         m_prf->final(ki);
+
+         std::copy(ki.begin(), ki.begin() + to_copy, p);
+         ++counter;
+
+         if (counter == 0)
+            throw Invalid_Argument("Can't process more than 4GB");
+
+         p += to_copy;
+         }
+
+   return key_len;
+   }
+}