add kdf1 implementation according to iso-18033 (preparation for ecies)

4 files changed, 81 insertions, 0 deletions

diff --git a/src/lib/kdf/kdf.cpp b/src/lib/kdf/kdf.cpp
index 7f4488d32..66296bf96 100644
--- a/src/lib/kdf/kdf.cpp
+++ b/src/lib/kdf/kdf.cpp
@@ -21,6 +21,10 @@
 #include <botan/kdf2.h>
 #endif
 
+#if defined(BOTAN_HAS_KDF1_18033)
+#include <botan/kdf1_iso18033.h>
+#endif
+
 #if defined(BOTAN_HAS_TLS_V10_PRF)
 #include <botan/prf_tls.h>
 #endif
@@ -89,6 +93,10 @@ BOTAN_REGISTER_KDF_1HASH(KDF1, "KDF1");
 BOTAN_REGISTER_KDF_1HASH(KDF2, "KDF2");
 #endif
 
+#if defined(BOTAN_HAS_KDF1_18033)
+BOTAN_REGISTER_KDF_1HASH( KDF1_18033, "KDF1-18033" );
+#endif
+
 #if defined(BOTAN_HAS_TLS_V10_PRF)
 BOTAN_REGISTER_KDF_NOARGS(TLS_PRF, "TLS-PRF");
 #endif
diff --git a/src/lib/kdf/kdf1_iso18033/info.txt b/src/lib/kdf/kdf1_iso18033/info.txt
new file mode 100644
index 000000000..507a04561
--- /dev/null
+++ b/src/lib/kdf/kdf1_iso18033/info.txt
@@ -0,0 +1 @@
+define KDF1_18033 20160128
diff --git a/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.cpp b/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.cpp
new file mode 100644
index 000000000..3ff717993
--- /dev/null
+++ b/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.cpp
@@ -0,0 +1,35 @@
+/*
+* KDF1 from ISO 18033
+* (C) 2016 Philipp Weber
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/kdf1_iso18033.h>
+
+namespace Botan {
+
+size_t KDF1_18033::kdf(byte key[], size_t key_len,
+                       const byte secret[], size_t secret_len,
+                       const byte salt[], size_t salt_len) const
+   {
+   u32bit counter = 0;
+   secure_vector<byte> h;
+
+   size_t offset = 0;
+   while(offset != key_len && counter != 0xFFFFFFFF)
+      {
+      m_hash->update(secret, secret_len);
+      m_hash->update_be(counter++);
+      m_hash->update(salt, salt_len);
+      m_hash->final(h);
+
+      const size_t added = std::min(h.size(), key_len - offset);
+      copy_mem(&key[offset], h.data(), added);
+      offset += added;
+      }
+
+   return offset;
+   }
+
+}
diff --git a/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.h b/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.h
new file mode 100644
index 000000000..6ec7ead8e
--- /dev/null
+++ b/src/lib/kdf/kdf1_iso18033/kdf1_iso18033.h
@@ -0,0 +1,37 @@
+/*
+* KDF1 from ISO 18033
+* (C) 2016 Philipp Weber
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_KDF1_18033_H__
+#define BOTAN_KDF1_18033_H__
+
+#include <botan/kdf.h>
+#include <botan/hash.h>
+
+namespace Botan {
+
+/**
+* KDF1, from IEEE 1363
+*/
+class BOTAN_DLL KDF1_18033 : public KDF
+   {
+   public:
+      std::string name() const override { return "KDF1-18033(" + m_hash->name() + ")"; }
+
+      KDF* clone() const override { return new KDF1_18033(m_hash->clone()); }
+
+      size_t kdf(byte key[], size_t key_len,
+                 const byte secret[], size_t secret_len,
+                 const byte salt[], size_t salt_len) const override;
+
+      KDF1_18033(HashFunction* h) : m_hash(h) {}
+   private:
+      std::unique_ptr<HashFunction> m_hash;
+   };
+
+}
+
+#endif