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authorlloyd <[email protected]>2008-09-28 19:29:24 +0000
committerlloyd <[email protected]>2008-09-28 19:29:24 +0000
commit9bcfe627321ddc81691b835dffaa6324ac4684a4 (patch)
treefe5e8ae9813b853549558b59833022e87e83981b /src/pk_pad/emsa2/emsa2.cpp
parent9822a701516396b7de4e41339faecd48ff8dc8ff (diff)
Move all modules into src/ directory
Diffstat (limited to 'src/pk_pad/emsa2/emsa2.cpp')
-rw-r--r--src/pk_pad/emsa2/emsa2.cpp106
1 files changed, 106 insertions, 0 deletions
diff --git a/src/pk_pad/emsa2/emsa2.cpp b/src/pk_pad/emsa2/emsa2.cpp
new file mode 100644
index 000000000..24292d390
--- /dev/null
+++ b/src/pk_pad/emsa2/emsa2.cpp
@@ -0,0 +1,106 @@
+/*************************************************
+* EMSA2 Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#include <botan/emsa2.h>
+#include <botan/hash_id.h>
+#include <botan/lookup.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* EMSA2 Encode Operation *
+*************************************************/
+SecureVector<byte> emsa2_encoding(const MemoryRegion<byte>& msg,
+ u32bit output_bits,
+ const MemoryRegion<byte>& empty_hash,
+ byte hash_id)
+ {
+ const u32bit HASH_SIZE = empty_hash.size();
+
+ u32bit output_length = (output_bits + 1) / 8;
+
+ if(msg.size() != HASH_SIZE)
+ throw Encoding_Error("EMSA2::encoding_of: Bad input length");
+ if(output_length < HASH_SIZE + 4)
+ throw Encoding_Error("EMSA2::encoding_of: Output length is too small");
+
+ bool empty = true;
+ for(u32bit j = 0; j != HASH_SIZE; ++j)
+ if(empty_hash[j] != msg[j])
+ empty = false;
+
+ SecureVector<byte> output(output_length);
+
+ output[0] = (empty ? 0x4B : 0x6B);
+ output[output_length - 3 - HASH_SIZE] = 0xBA;
+ set_mem(output + 1, output_length - 4 - HASH_SIZE, 0xBB);
+ output.copy(output_length - (HASH_SIZE + 2), msg, msg.size());
+ output[output_length-2] = hash_id;
+ output[output_length-1] = 0xCC;
+
+ return output;
+ }
+
+}
+
+/*************************************************
+* EMSA2 Update Operation *
+*************************************************/
+void EMSA2::update(const byte input[], u32bit length)
+ {
+ hash->update(input, length);
+ }
+
+/*************************************************
+* Return the raw (unencoded) data *
+*************************************************/
+SecureVector<byte> EMSA2::raw_data()
+ {
+ return hash->final();
+ }
+
+/*************************************************
+* EMSA2 Encode Operation *
+*************************************************/
+SecureVector<byte> EMSA2::encoding_of(const MemoryRegion<byte>& msg,
+ u32bit output_bits,
+ RandomNumberGenerator&)
+ {
+ return emsa2_encoding(msg, output_bits, empty_hash, hash_id);
+ }
+
+/*************************************************
+* EMSA2 Verify Operation *
+*************************************************/
+bool EMSA2::verify(const MemoryRegion<byte>& coded,
+ const MemoryRegion<byte>& raw,
+ u32bit key_bits) throw()
+ {
+ try
+ {
+ return (coded == emsa2_encoding(raw, key_bits,
+ empty_hash, hash_id));
+ }
+ catch(...)
+ {
+ return false;
+ }
+ }
+
+/*************************************************
+* EMSA2 Constructor *
+*************************************************/
+EMSA2::EMSA2(const std::string& hash_name)
+ {
+ hash_id = ieee1363_hash_id(hash_name);
+ if(hash_id == 0)
+ throw Encoding_Error("EMSA2 cannot be used with " + hash->name());
+ hash = get_hash(hash_name);
+ empty_hash = hash->final();
+ }
+
+}