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authorlloyd <[email protected]>2008-11-08 19:46:52 +0000
committerlloyd <[email protected]>2008-11-08 19:46:52 +0000
commitf1c459725da56fd8ed5766e7779300182fa26bcf (patch)
tree32295cec92df1155563ae8a535dc695d6800d7f6 /src/stream/salsa20/salsa20.cpp
parent8dba7b5264403e781bbb86ff61850e4377dca7b9 (diff)
Split ciphers into block and stream ciphers. Move base class headers
Diffstat (limited to 'src/stream/salsa20/salsa20.cpp')
-rw-r--r--src/stream/salsa20/salsa20.cpp215
1 files changed, 215 insertions, 0 deletions
diff --git a/src/stream/salsa20/salsa20.cpp b/src/stream/salsa20/salsa20.cpp
new file mode 100644
index 000000000..c2c8f289f
--- /dev/null
+++ b/src/stream/salsa20/salsa20.cpp
@@ -0,0 +1,215 @@
+/*************************************************
+* Salsa20 Source File *
+* (C) 1999-2008 Jack Lloyd *
+*************************************************/
+
+#include <botan/salsa20.h>
+#include <botan/mem_ops.h>
+#include <botan/xor_buf.h>
+#include <botan/loadstor.h>
+#include <botan/parsing.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Generate Salsa20 cipher stream *
+*************************************************/
+void salsa20(byte output[64], const u32bit input[16])
+ {
+ u32bit x00 = input[0];
+ u32bit x01 = input[1];
+ u32bit x02 = input[2];
+ u32bit x03 = input[3];
+ u32bit x04 = input[4];
+ u32bit x05 = input[5];
+ u32bit x06 = input[6];
+ u32bit x07 = input[7];
+ u32bit x08 = input[8];
+ u32bit x09 = input[9];
+ u32bit x10 = input[10];
+ u32bit x11 = input[11];
+ u32bit x12 = input[12];
+ u32bit x13 = input[13];
+ u32bit x14 = input[14];
+ u32bit x15 = input[15];
+
+ for(u32bit i = 0; i != 10; ++i)
+ {
+ x04 ^= rotate_left(x00 + x12, 7);
+ x08 ^= rotate_left(x04 + x00, 9);
+ x12 ^= rotate_left(x08 + x04, 13);
+ x00 ^= rotate_left(x12 + x08, 18);
+ x09 ^= rotate_left(x05 + x01, 7);
+ x13 ^= rotate_left(x09 + x05, 9);
+ x01 ^= rotate_left(x13 + x09, 13);
+ x05 ^= rotate_left(x01 + x13, 18);
+ x14 ^= rotate_left(x10 + x06, 7);
+ x02 ^= rotate_left(x14 + x10, 9);
+ x06 ^= rotate_left(x02 + x14, 13);
+ x10 ^= rotate_left(x06 + x02, 18);
+ x03 ^= rotate_left(x15 + x11, 7);
+ x07 ^= rotate_left(x03 + x15, 9);
+ x11 ^= rotate_left(x07 + x03, 13);
+ x15 ^= rotate_left(x11 + x07, 18);
+
+ x01 ^= rotate_left(x00 + x03, 7);
+ x02 ^= rotate_left(x01 + x00, 9);
+ x03 ^= rotate_left(x02 + x01, 13);
+ x00 ^= rotate_left(x03 + x02, 18);
+ x06 ^= rotate_left(x05 + x04, 7);
+ x07 ^= rotate_left(x06 + x05, 9);
+ x04 ^= rotate_left(x07 + x06, 13);
+ x05 ^= rotate_left(x04 + x07, 18);
+ x11 ^= rotate_left(x10 + x09, 7);
+ x08 ^= rotate_left(x11 + x10, 9);
+ x09 ^= rotate_left(x08 + x11, 13);
+ x10 ^= rotate_left(x09 + x08, 18);
+ x12 ^= rotate_left(x15 + x14, 7);
+ x13 ^= rotate_left(x12 + x15, 9);
+ x14 ^= rotate_left(x13 + x12, 13);
+ x15 ^= rotate_left(x14 + x13, 18);
+ }
+
+ store_le(x00 + input[ 0], output + 4 * 0);
+ store_le(x01 + input[ 1], output + 4 * 1);
+ store_le(x02 + input[ 2], output + 4 * 2);
+ store_le(x03 + input[ 3], output + 4 * 3);
+ store_le(x04 + input[ 4], output + 4 * 4);
+ store_le(x05 + input[ 5], output + 4 * 5);
+ store_le(x06 + input[ 6], output + 4 * 6);
+ store_le(x07 + input[ 7], output + 4 * 7);
+ store_le(x08 + input[ 8], output + 4 * 8);
+ store_le(x09 + input[ 9], output + 4 * 9);
+ store_le(x10 + input[10], output + 4 * 10);
+ store_le(x11 + input[11], output + 4 * 11);
+ store_le(x12 + input[12], output + 4 * 12);
+ store_le(x13 + input[13], output + 4 * 13);
+ store_le(x14 + input[14], output + 4 * 14);
+ store_le(x15 + input[15], output + 4 * 15);
+ }
+
+}
+
+/*************************************************
+* Combine cipher stream with message *
+*************************************************/
+void Salsa20::cipher(const byte in[], byte out[], u32bit length)
+ {
+ while(length >= buffer.size() - position)
+ {
+ xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+ length -= (buffer.size() - position);
+ in += (buffer.size() - position);
+ out += (buffer.size() - position);
+ salsa20(buffer.begin(), state);
+
+ ++state[8];
+ if(!state[8]) // if overflow in state[8]
+ ++state[9]; // carry to state[9]
+
+ position = 0;
+ }
+
+ xor_buf(out, in, buffer.begin() + position, length);
+
+ position += length;
+ }
+
+/*************************************************
+* Salsa20 Key Schedule *
+*************************************************/
+void Salsa20::key(const byte key[], u32bit length)
+ {
+ static const u32bit TAU[] =
+ { 0x61707865, 0x3120646e, 0x79622d36, 0x6b206574 };
+
+ static const u32bit SIGMA[] =
+ { 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574 };
+
+ clear();
+
+ if(length == 16)
+ {
+ state[0] = TAU[0];
+ state[1] = load_le<u32bit>(key, 0);
+ state[2] = load_le<u32bit>(key, 1);
+ state[3] = load_le<u32bit>(key, 2);
+ state[4] = load_le<u32bit>(key, 3);
+ state[5] = TAU[1];
+ state[10] = TAU[2];
+ state[11] = load_le<u32bit>(key, 0);
+ state[12] = load_le<u32bit>(key, 1);
+ state[13] = load_le<u32bit>(key, 2);
+ state[14] = load_le<u32bit>(key, 3);
+ state[15] = TAU[3];
+ }
+ else if(length == 32)
+ {
+ state[0] = SIGMA[0];
+ state[1] = load_le<u32bit>(key, 0);
+ state[2] = load_le<u32bit>(key, 1);
+ state[3] = load_le<u32bit>(key, 2);
+ state[4] = load_le<u32bit>(key, 3);
+ state[5] = SIGMA[1];
+ state[10] = SIGMA[2];
+ state[11] = load_le<u32bit>(key, 4);
+ state[12] = load_le<u32bit>(key, 5);
+ state[13] = load_le<u32bit>(key, 6);
+ state[14] = load_le<u32bit>(key, 7);
+ state[15] = SIGMA[3];
+ }
+
+ const byte ZERO[8] = { 0 };
+ resync(ZERO, sizeof(ZERO));
+ }
+
+/*************************************************
+* Return the name of this type *
+*************************************************/
+void Salsa20::resync(const byte iv[], u32bit length)
+ {
+ if(length != IV_LENGTH)
+ throw Invalid_IV_Length(name(), length);
+
+ state[6] = load_le<u32bit>(iv, 0);
+ state[7] = load_le<u32bit>(iv, 1);
+ state[8] = 0;
+ state[9] = 0;
+
+ salsa20(buffer.begin(), state);
+ ++state[8];
+ if(!state[8]) // if overflow in state[8]
+ ++state[9]; // carry to state[9]
+
+ position = 0;
+ }
+
+/*************************************************
+* Return the name of this type *
+*************************************************/
+std::string Salsa20::name() const
+ {
+ return "Salsa20";
+ }
+
+/*************************************************
+* Clear memory of sensitive data *
+*************************************************/
+void Salsa20::clear() throw()
+ {
+ state.clear();
+ buffer.clear();
+ position = 0;
+ }
+
+/*************************************************
+* Salsa20 Constructor *
+*************************************************/
+Salsa20::Salsa20() : StreamCipher(16, 32, 16, 8)
+ {
+ clear();
+ }
+
+}