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authorlloyd <[email protected]>2009-11-17 07:19:37 +0000
committerlloyd <[email protected]>2009-11-17 07:19:37 +0000
commite00b46cf9c1dcb364ebb7d5968d6ff9dcd600c4e (patch)
tree8ffb8d032f06bbcb7ab376c7469751a25b556dca /src/constructs/aont/package.cpp
parenta98a9ff5f95bd4dca9c1eda11e27e712c869cd66 (diff)
Move most code that relies heavily on Filters into src/filters.
Remove support for (unused) modset settings. Move tss, fpe, cryptobox, and aont to new dir constructs
Diffstat (limited to 'src/constructs/aont/package.cpp')
-rw-r--r--src/constructs/aont/package.cpp120
1 files changed, 120 insertions, 0 deletions
diff --git a/src/constructs/aont/package.cpp b/src/constructs/aont/package.cpp
new file mode 100644
index 000000000..37bad46c8
--- /dev/null
+++ b/src/constructs/aont/package.cpp
@@ -0,0 +1,120 @@
+/*
+* Rivest's Package Tranform
+*
+* (C) 2009 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/package.h>
+#include <botan/filters.h>
+#include <botan/ctr.h>
+#include <botan/loadstor.h>
+#include <botan/xor_buf.h>
+
+namespace Botan {
+
+namespace AllOrNothingTransform {
+
+void package(RandomNumberGenerator& rng,
+ BlockCipher* cipher,
+ const byte input[], u32bit input_len,
+ byte output[])
+ {
+ if(!cipher->valid_keylength(cipher->BLOCK_SIZE))
+ throw Invalid_Argument("AONT::package: Invalid cipher");
+
+ // The all-zero string which is used both as the CTR IV and as K0
+ const std::string all_zeros(cipher->BLOCK_SIZE*2, '0');
+
+ SymmetricKey package_key(rng, cipher->BLOCK_SIZE);
+
+ Pipe pipe(new StreamCipher_Filter(new CTR_BE(cipher), package_key));
+
+ pipe.process_msg(input, input_len);
+ pipe.read(output, pipe.remaining());
+
+ // Set K0 (the all zero key)
+ cipher->set_key(SymmetricKey(all_zeros));
+
+ SecureVector<byte> buf(cipher->BLOCK_SIZE);
+
+ const u32bit blocks =
+ (input_len + cipher->BLOCK_SIZE - 1) / cipher->BLOCK_SIZE;
+
+ byte* final_block = output + input_len;
+ clear_mem(final_block, cipher->BLOCK_SIZE);
+
+ // XOR the hash blocks into the final block
+ for(u32bit i = 0; i != blocks; ++i)
+ {
+ u32bit left = std::min<u32bit>(cipher->BLOCK_SIZE,
+ input_len - cipher->BLOCK_SIZE * i);
+
+ buf.clear();
+ copy_mem(&buf[0], output + cipher->BLOCK_SIZE * i, left);
+
+ for(u32bit j = 0; j != 4; ++j)
+ buf[cipher->BLOCK_SIZE - 1 - j] ^= get_byte(3-j, i);
+
+ cipher->encrypt(buf);
+
+ xor_buf(final_block, buf, cipher->BLOCK_SIZE);
+ }
+
+ // XOR the random package key into the final block
+ xor_buf(final_block, package_key.begin(), cipher->BLOCK_SIZE);
+ }
+
+void unpackage(BlockCipher* cipher,
+ const byte input[], u32bit input_len,
+ byte output[])
+ {
+ if(!cipher->valid_keylength(cipher->BLOCK_SIZE))
+ throw Invalid_Argument("AONT::unpackage: Invalid cipher");
+
+ if(input_len < cipher->BLOCK_SIZE)
+ throw Invalid_Argument("AONT::unpackage: Input too short");
+
+ // The all-zero string which is used both as the CTR IV and as K0
+ const std::string all_zeros(cipher->BLOCK_SIZE*2, '0');
+
+ cipher->set_key(SymmetricKey(all_zeros));
+
+ SecureVector<byte> package_key(cipher->BLOCK_SIZE);
+ SecureVector<byte> buf(cipher->BLOCK_SIZE);
+
+ // Copy the package key (masked with the block hashes)
+ copy_mem(&package_key[0],
+ input + (input_len - cipher->BLOCK_SIZE),
+ cipher->BLOCK_SIZE);
+
+ const u32bit blocks = ((input_len - 1) / cipher->BLOCK_SIZE);
+
+ // XOR the blocks into the package key bits
+ for(u32bit i = 0; i != blocks; ++i)
+ {
+ u32bit left = std::min<u32bit>(cipher->BLOCK_SIZE,
+ input_len - cipher->BLOCK_SIZE * (i+1));
+
+ buf.clear();
+ copy_mem(&buf[0], input + cipher->BLOCK_SIZE * i, left);
+
+ for(u32bit j = 0; j != 4; ++j)
+ buf[cipher->BLOCK_SIZE - 1 - j] ^= get_byte(3-j, i);
+
+ cipher->encrypt(buf);
+
+ xor_buf(&package_key[0], buf, cipher->BLOCK_SIZE);
+ }
+
+ Pipe pipe(new StreamCipher_Filter(new CTR_BE(cipher), package_key));
+
+ pipe.process_msg(input, input_len - cipher->BLOCK_SIZE);
+
+ pipe.read(output, pipe.remaining());
+ }
+
+}
+
+}