3 files changed, 121 insertions, 0 deletions
diff --git a/src/lib/hash/checksum/adler32/adler32.cpp b/src/lib/hash/checksum/adler32/adler32.cpp
new file mode 100644
index 000000000..f2385c5b8
--- /dev/null
+++ b/src/lib/hash/checksum/adler32/adler32.cpp
@@ -0,0 +1,83 @@
+/*
+* Adler32
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/hash_utils.h>
+#include <botan/adler32.h>
+
+namespace Botan {
+
+BOTAN_REGISTER_HASH_NOARGS(Adler32);
+
+namespace {
+
+void adler32_update(const byte input[], size_t length,
+                    u16bit& S1, u16bit& S2)
+   {
+   u32bit S1x = S1;
+   u32bit S2x = S2;
+
+   while(length >= 16)
+      {
+      S1x += input[ 0]; S2x += S1x;
+      S1x += input[ 1]; S2x += S1x;
+      S1x += input[ 2]; S2x += S1x;
+      S1x += input[ 3]; S2x += S1x;
+      S1x += input[ 4]; S2x += S1x;
+      S1x += input[ 5]; S2x += S1x;
+      S1x += input[ 6]; S2x += S1x;
+      S1x += input[ 7]; S2x += S1x;
+      S1x += input[ 8]; S2x += S1x;
+      S1x += input[ 9]; S2x += S1x;
+      S1x += input[10]; S2x += S1x;
+      S1x += input[11]; S2x += S1x;
+      S1x += input[12]; S2x += S1x;
+      S1x += input[13]; S2x += S1x;
+      S1x += input[14]; S2x += S1x;
+      S1x += input[15]; S2x += S1x;
+      input += 16;
+      length -= 16;
+      }
+
+   for(size_t j = 0; j != length; ++j)
+      {
+      S1x += input[j];
+      S2x += S1x;
+      }
+
+   S1 = S1x % 65521;
+   S2 = S2x % 65521;
+   }
+
+}
+
+/*
+* Update an Adler32 Checksum
+*/
+void Adler32::add_data(const byte input[], size_t length)
+   {
+   const size_t PROCESS_AMOUNT = 5552;
+
+   while(length >= PROCESS_AMOUNT)
+      {
+      adler32_update(input, PROCESS_AMOUNT, S1, S2);
+      input += PROCESS_AMOUNT;
+      length -= PROCESS_AMOUNT;
+      }
+
+   adler32_update(input, length, S1, S2);
+   }
+
+/*
+* Finalize an Adler32 Checksum
+*/
+void Adler32::final_result(byte output[])
+   {
+   store_be(output, S2, S1);
+   clear();
+   }
+
+}
diff --git a/src/lib/hash/checksum/adler32/adler32.h b/src/lib/hash/checksum/adler32/adler32.h
new file mode 100644
index 000000000..f3767b786
--- /dev/null
+++ b/src/lib/hash/checksum/adler32/adler32.h
@@ -0,0 +1,37 @@
+/*
+* Adler32
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_ADLER32_H__
+#define BOTAN_ADLER32_H__
+
+#include <botan/hash.h>
+
+namespace Botan {
+
+/**
+* The Adler32 checksum, used in zlib
+*/
+class BOTAN_DLL Adler32 : public HashFunction
+   {
+   public:
+      std::string name() const { return "Adler32"; }
+      size_t output_length() const { return 4; }
+      HashFunction* clone() const { return new Adler32; }
+
+      void clear() { S1 = 1; S2 = 0; }
+
+      Adler32() { clear(); }
+      ~Adler32() { clear(); }
+   private:
+      void add_data(const byte[], size_t);
+      void final_result(byte[]);
+      u16bit S1, S2;
+   };
+
+}
+
+#endif
diff --git a/src/lib/hash/checksum/adler32/info.txt b/src/lib/hash/checksum/adler32/info.txt
new file mode 100644
index 000000000..26ca8b255
--- /dev/null
+++ b/src/lib/hash/checksum/adler32/info.txt
@@ -0,0 +1 @@
+define ADLER32 20131128