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authorlloyd <[email protected]>2014-01-10 03:41:59 +0000
committerlloyd <[email protected]>2014-01-10 03:41:59 +0000
commit6894dca64c04936d07048c0e8cbf7e25858548c3 (patch)
tree5d572bfde9fe667dab14e3f04b5285a85d8acd95 /src/lib/block/cascade/cascade.cpp
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/block/cascade/cascade.cpp')
-rw-r--r--src/lib/block/cascade/cascade.cpp98
1 files changed, 98 insertions, 0 deletions
diff --git a/src/lib/block/cascade/cascade.cpp b/src/lib/block/cascade/cascade.cpp
new file mode 100644
index 000000000..f1b1a8f2c
--- /dev/null
+++ b/src/lib/block/cascade/cascade.cpp
@@ -0,0 +1,98 @@
+/*
+* Block Cipher Cascade
+* (C) 2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/cascade.h>
+
+namespace Botan {
+
+void Cascade_Cipher::encrypt_n(const byte in[], byte out[],
+ size_t blocks) const
+ {
+ size_t c1_blocks = blocks * (block_size() / cipher1->block_size());
+ size_t c2_blocks = blocks * (block_size() / cipher2->block_size());
+
+ cipher1->encrypt_n(in, out, c1_blocks);
+ cipher2->encrypt_n(out, out, c2_blocks);
+ }
+
+void Cascade_Cipher::decrypt_n(const byte in[], byte out[],
+ size_t blocks) const
+ {
+ size_t c1_blocks = blocks * (block_size() / cipher1->block_size());
+ size_t c2_blocks = blocks * (block_size() / cipher2->block_size());
+
+ cipher2->decrypt_n(in, out, c2_blocks);
+ cipher1->decrypt_n(out, out, c1_blocks);
+ }
+
+void Cascade_Cipher::key_schedule(const byte key[], size_t)
+ {
+ const byte* key2 = key + cipher1->maximum_keylength();
+
+ cipher1->set_key(key , cipher1->maximum_keylength());
+ cipher2->set_key(key2, cipher2->maximum_keylength());
+ }
+
+void Cascade_Cipher::clear()
+ {
+ cipher1->clear();
+ cipher2->clear();
+ }
+
+std::string Cascade_Cipher::name() const
+ {
+ return "Cascade(" + cipher1->name() + "," + cipher2->name() + ")";
+ }
+
+BlockCipher* Cascade_Cipher::clone() const
+ {
+ return new Cascade_Cipher(cipher1->clone(),
+ cipher2->clone());
+ }
+
+namespace {
+
+size_t euclids_algorithm(size_t a, size_t b)
+ {
+ while(b != 0) // gcd
+ {
+ size_t t = b;
+ b = a % b;
+ a = t;
+ }
+
+ return a;
+ }
+
+size_t block_size_for_cascade(size_t bs, size_t bs2)
+ {
+ if(bs == bs2)
+ return bs;
+
+ size_t gcd = euclids_algorithm(bs, bs2);
+
+ return (bs * bs2) / gcd;
+ }
+
+}
+
+Cascade_Cipher::Cascade_Cipher(BlockCipher* c1, BlockCipher* c2) :
+ cipher1(c1), cipher2(c2)
+ {
+ block = block_size_for_cascade(c1->block_size(), c2->block_size());
+
+ if(block_size() % c1->block_size() || block_size() % c2->block_size())
+ throw Internal_Error("Failure in " + name() + " constructor");
+ }
+
+Cascade_Cipher::~Cascade_Cipher()
+ {
+ delete cipher1;
+ delete cipher2;
+ }
+
+}