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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/constructs/rfc3394/rfc3394.cpp
parent9efa3be92442afb3d0b69890a36c7f122df18eda (diff)
Move lib into src
Diffstat (limited to 'src/lib/constructs/rfc3394/rfc3394.cpp')
-rw-r--r--src/lib/constructs/rfc3394/rfc3394.cpp122
1 files changed, 122 insertions, 0 deletions
diff --git a/src/lib/constructs/rfc3394/rfc3394.cpp b/src/lib/constructs/rfc3394/rfc3394.cpp
new file mode 100644
index 000000000..cfe95f40b
--- /dev/null
+++ b/src/lib/constructs/rfc3394/rfc3394.cpp
@@ -0,0 +1,122 @@
+/*
+* AES Key Wrap (RFC 3394)
+* (C) 2011 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/rfc3394.h>
+#include <botan/algo_factory.h>
+#include <botan/block_cipher.h>
+#include <botan/loadstor.h>
+#include <botan/exceptn.h>
+#include <botan/internal/xor_buf.h>
+#include <memory>
+
+namespace Botan {
+
+namespace {
+
+BlockCipher* make_aes(size_t keylength,
+ Algorithm_Factory& af)
+ {
+ if(keylength == 16)
+ return af.make_block_cipher("AES-128");
+ else if(keylength == 24)
+ return af.make_block_cipher("AES-192");
+ else if(keylength == 32)
+ return af.make_block_cipher("AES-256");
+ else
+ throw std::invalid_argument("Bad KEK length for NIST keywrap");
+ }
+
+}
+
+secure_vector<byte> rfc3394_keywrap(const secure_vector<byte>& key,
+ const SymmetricKey& kek,
+ Algorithm_Factory& af)
+ {
+ if(key.size() % 8 != 0)
+ throw std::invalid_argument("Bad input key size for NIST key wrap");
+
+ std::unique_ptr<BlockCipher> aes(make_aes(kek.length(), af));
+ aes->set_key(kek);
+
+ const size_t n = key.size() / 8;
+
+ secure_vector<byte> R((n + 1) * 8);
+ secure_vector<byte> A(16);
+
+ for(size_t i = 0; i != 8; ++i)
+ A[i] = 0xA6;
+
+ copy_mem(&R[8], &key[0], key.size());
+
+ for(size_t j = 0; j <= 5; ++j)
+ {
+ for(size_t i = 1; i <= n; ++i)
+ {
+ const u32bit t = (n * j) + i;
+
+ copy_mem(&A[8], &R[8*i], 8);
+
+ aes->encrypt(&A[0]);
+ copy_mem(&R[8*i], &A[8], 8);
+
+ byte t_buf[4] = { 0 };
+ store_be(t, t_buf);
+ xor_buf(&A[4], &t_buf[0], 4);
+ }
+ }
+
+ copy_mem(&R[0], &A[0], 8);
+
+ return R;
+ }
+
+secure_vector<byte> rfc3394_keyunwrap(const secure_vector<byte>& key,
+ const SymmetricKey& kek,
+ Algorithm_Factory& af)
+ {
+ if(key.size() < 16 || key.size() % 8 != 0)
+ throw std::invalid_argument("Bad input key size for NIST key unwrap");
+
+ std::unique_ptr<BlockCipher> aes(make_aes(kek.length(), af));
+ aes->set_key(kek);
+
+ const size_t n = (key.size() - 8) / 8;
+
+ secure_vector<byte> R(n * 8);
+ secure_vector<byte> A(16);
+
+ for(size_t i = 0; i != 8; ++i)
+ A[i] = key[i];
+
+ copy_mem(&R[0], &key[8], key.size() - 8);
+
+ for(size_t j = 0; j <= 5; ++j)
+ {
+ for(size_t i = n; i != 0; --i)
+ {
+ const u32bit t = (5 - j) * n + i;
+
+ byte t_buf[4] = { 0 };
+ store_be(t, t_buf);
+
+ xor_buf(&A[4], &t_buf[0], 4);
+
+ copy_mem(&A[8], &R[8*(i-1)], 8);
+
+ aes->decrypt(&A[0]);
+
+ copy_mem(&R[8*(i-1)], &A[8], 8);
+ }
+ }
+
+ if(load_be<u64bit>(&A[0], 0) != 0xA6A6A6A6A6A6A6A6)
+ throw Integrity_Failure("NIST key unwrap failed");
+
+ return R;
+ }
+
+}