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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/modes/cfb/cfb.cpp
parent9822a701516396b7de4e41339faecd48ff8dc8ff (diff)
Move all modules into src/ directory
Diffstat (limited to 'src/modes/cfb/cfb.cpp')
-rw-r--r--src/modes/cfb/cfb.cpp142
1 files changed, 142 insertions, 0 deletions
diff --git a/src/modes/cfb/cfb.cpp b/src/modes/cfb/cfb.cpp
new file mode 100644
index 000000000..dbfbff6ae
--- /dev/null
+++ b/src/modes/cfb/cfb.cpp
@@ -0,0 +1,142 @@
+/*************************************************
+* CFB Mode Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#include <botan/cfb.h>
+#include <botan/lookup.h>
+#include <botan/parsing.h>
+#include <botan/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Check the feedback size *
+*************************************************/
+void check_feedback(u32bit BLOCK_SIZE, u32bit FEEDBACK_SIZE, u32bit bits,
+ const std::string& name)
+ {
+ if(FEEDBACK_SIZE == 0 || FEEDBACK_SIZE > BLOCK_SIZE || bits % 8 != 0)
+ throw Invalid_Argument(name + ": Invalid feedback size " +
+ to_string(bits));
+ }
+
+}
+
+/*************************************************
+* CFB Encryption Constructor *
+*************************************************/
+CFB_Encryption::CFB_Encryption(const std::string& cipher_name,
+ u32bit fback_bits) :
+ BlockCipherMode(cipher_name, "CFB", block_size_of(cipher_name), 1),
+ FEEDBACK_SIZE(fback_bits ? fback_bits / 8: BLOCK_SIZE)
+ {
+ check_feedback(BLOCK_SIZE, FEEDBACK_SIZE, fback_bits, name());
+ }
+
+/*************************************************
+* CFB Encryption Constructor *
+*************************************************/
+CFB_Encryption::CFB_Encryption(const std::string& cipher_name,
+ const SymmetricKey& key,
+ const InitializationVector& iv,
+ u32bit fback_bits) :
+ BlockCipherMode(cipher_name, "CFB", block_size_of(cipher_name), 1),
+ FEEDBACK_SIZE(fback_bits ? fback_bits / 8: BLOCK_SIZE)
+ {
+ check_feedback(BLOCK_SIZE, FEEDBACK_SIZE, fback_bits, name());
+ set_key(key);
+ set_iv(iv);
+ }
+
+/*************************************************
+* Encrypt data in CFB mode *
+*************************************************/
+void CFB_Encryption::write(const byte input[], u32bit length)
+ {
+ while(length)
+ {
+ u32bit xored = std::min(FEEDBACK_SIZE - position, length);
+ xor_buf(buffer + position, input, xored);
+ send(buffer + position, xored);
+ input += xored;
+ length -= xored;
+ position += xored;
+ if(position == FEEDBACK_SIZE)
+ feedback();
+ }
+ }
+
+/*************************************************
+* Do the feedback *
+*************************************************/
+void CFB_Encryption::feedback()
+ {
+ for(u32bit j = 0; j != BLOCK_SIZE - FEEDBACK_SIZE; ++j)
+ state[j] = state[j + FEEDBACK_SIZE];
+ state.copy(BLOCK_SIZE - FEEDBACK_SIZE, buffer, FEEDBACK_SIZE);
+ cipher->encrypt(state, buffer);
+ position = 0;
+ }
+
+/*************************************************
+* CFB Decryption Constructor *
+*************************************************/
+CFB_Decryption::CFB_Decryption(const std::string& cipher_name,
+ u32bit fback_bits) :
+ BlockCipherMode(cipher_name, "CFB", block_size_of(cipher_name), 1),
+ FEEDBACK_SIZE(fback_bits ? fback_bits / 8 : BLOCK_SIZE)
+ {
+ check_feedback(BLOCK_SIZE, FEEDBACK_SIZE, fback_bits, name());
+ }
+
+/*************************************************
+* CFB Decryption Constructor *
+*************************************************/
+CFB_Decryption::CFB_Decryption(const std::string& cipher_name,
+ const SymmetricKey& key,
+ const InitializationVector& iv,
+ u32bit fback_bits) :
+ BlockCipherMode(cipher_name, "CFB", block_size_of(cipher_name), 1),
+ FEEDBACK_SIZE(fback_bits ? fback_bits / 8 : BLOCK_SIZE)
+ {
+ check_feedback(BLOCK_SIZE, FEEDBACK_SIZE, fback_bits, name());
+ set_key(key);
+ set_iv(iv);
+ }
+
+/*************************************************
+* Decrypt data in CFB mode *
+*************************************************/
+void CFB_Decryption::write(const byte input[], u32bit length)
+ {
+ while(length)
+ {
+ u32bit xored = std::min(FEEDBACK_SIZE - position, length);
+ xor_buf(buffer + position, input, xored);
+ send(buffer + position, xored);
+ buffer.copy(position, input, xored);
+ input += xored;
+ length -= xored;
+ position += xored;
+ if(position == FEEDBACK_SIZE)
+ feedback();
+ }
+ }
+
+/*************************************************
+* Do the feedback *
+*************************************************/
+void CFB_Decryption::feedback()
+ {
+ for(u32bit j = 0; j != BLOCK_SIZE - FEEDBACK_SIZE; ++j)
+ state[j] = state[j + FEEDBACK_SIZE];
+ state.copy(BLOCK_SIZE - FEEDBACK_SIZE, buffer, FEEDBACK_SIZE);
+ cipher->encrypt(state, buffer);
+ position = 0;
+ }
+
+}