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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/stream/ofb
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/stream/ofb')
-rw-r--r--src/lib/stream/ofb/info.txt6
-rw-r--r--src/lib/stream/ofb/ofb.cpp93
-rw-r--r--src/lib/stream/ofb/ofb.h56
3 files changed, 155 insertions, 0 deletions
diff --git a/src/lib/stream/ofb/info.txt b/src/lib/stream/ofb/info.txt
new file mode 100644
index 000000000..11b6bfb27
--- /dev/null
+++ b/src/lib/stream/ofb/info.txt
@@ -0,0 +1,6 @@
+define OFB 20131128
+
+<requires>
+block
+stream
+</requires>
diff --git a/src/lib/stream/ofb/ofb.cpp b/src/lib/stream/ofb/ofb.cpp
new file mode 100644
index 000000000..1137a58af
--- /dev/null
+++ b/src/lib/stream/ofb/ofb.cpp
@@ -0,0 +1,93 @@
+/*
+* OFB Mode
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/ofb.h>
+#include <botan/internal/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*
+* OFB Constructor
+*/
+OFB::OFB(BlockCipher* ciph) : permutation(ciph)
+ {
+ position = 0;
+ buffer.resize(permutation->block_size());
+ }
+
+/*
+* OFB Destructor
+*/
+OFB::~OFB()
+ {
+ delete permutation;
+ }
+
+/*
+* Zeroize
+*/
+void OFB::clear()
+ {
+ permutation->clear();
+ zeroise(buffer);
+ position = 0;
+ }
+
+/*
+* Set the key
+*/
+void OFB::key_schedule(const byte key[], size_t key_len)
+ {
+ permutation->set_key(key, key_len);
+
+ // Set a default all-zeros IV
+ set_iv(nullptr, 0);
+ }
+
+/*
+* Return the name of this type
+*/
+std::string OFB::name() const
+ {
+ return ("OFB(" + permutation->name() + ")");
+ }
+
+/*
+* CTR-BE Encryption/Decryption
+*/
+void OFB::cipher(const byte in[], byte out[], size_t length)
+ {
+ while(length >= buffer.size() - position)
+ {
+ xor_buf(out, in, &buffer[position], buffer.size() - position);
+ length -= (buffer.size() - position);
+ in += (buffer.size() - position);
+ out += (buffer.size() - position);
+ permutation->encrypt(buffer);
+ position = 0;
+ }
+ xor_buf(out, in, &buffer[position], length);
+ position += length;
+ }
+
+/*
+* Set CTR-BE IV
+*/
+void OFB::set_iv(const byte iv[], size_t iv_len)
+ {
+ if(!valid_iv_length(iv_len))
+ throw Invalid_IV_Length(name(), iv_len);
+
+ zeroise(buffer);
+ buffer_insert(buffer, 0, iv, iv_len);
+
+ permutation->encrypt(buffer);
+ position = 0;
+ }
+
+}
diff --git a/src/lib/stream/ofb/ofb.h b/src/lib/stream/ofb/ofb.h
new file mode 100644
index 000000000..9d4fd882f
--- /dev/null
+++ b/src/lib/stream/ofb/ofb.h
@@ -0,0 +1,56 @@
+/*
+* OFB Mode
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_OUTPUT_FEEDBACK_MODE_H__
+#define BOTAN_OUTPUT_FEEDBACK_MODE_H__
+
+#include <botan/stream_cipher.h>
+#include <botan/block_cipher.h>
+
+namespace Botan {
+
+/**
+* Output Feedback Mode
+*/
+class BOTAN_DLL OFB : public StreamCipher
+ {
+ public:
+ void cipher(const byte in[], byte out[], size_t length);
+
+ void set_iv(const byte iv[], size_t iv_len);
+
+ bool valid_iv_length(size_t iv_len) const
+ { return (iv_len <= permutation->block_size()); }
+
+ Key_Length_Specification key_spec() const
+ {
+ return permutation->key_spec();
+ }
+
+ std::string name() const;
+
+ OFB* clone() const
+ { return new OFB(permutation->clone()); }
+
+ void clear();
+
+ /**
+ * @param cipher the underlying block cipher to use
+ */
+ OFB(BlockCipher* cipher);
+ ~OFB();
+ private:
+ void key_schedule(const byte key[], size_t key_len);
+
+ BlockCipher* permutation;
+ secure_vector<byte> buffer;
+ size_t position;
+ };
+
+}
+
+#endif