1 files changed, 35 insertions, 0 deletions

diff --git a/nacl/curvecp/crypto_block.c b/nacl/curvecp/crypto_block.c
new file mode 100644
index 00000000..5c7cf35e
--- /dev/null
+++ b/nacl/curvecp/crypto_block.c
@@ -0,0 +1,35 @@
+#include "crypto_block.h"
+#include "crypto_uint64.h"
+#include "uint64_unpack.h"
+#include "uint64_pack.h"
+
+/*
+TEA with double-size words.
+XXX: Switch to crypto_block_aes256.
+XXX: Build crypto_stream_aes256 on top of crypto_block_aes256.
+*/
+
+int crypto_block(
+  unsigned char *out,
+  const unsigned char *in,
+  const unsigned char *k
+)
+{
+  crypto_uint64 v0 = uint64_unpack(in + 0);
+  crypto_uint64 v1 = uint64_unpack(in + 8);
+  crypto_uint64 k0 = uint64_unpack(k + 0);
+  crypto_uint64 k1 = uint64_unpack(k + 8);
+  crypto_uint64 k2 = uint64_unpack(k + 16);
+  crypto_uint64 k3 = uint64_unpack(k + 24);
+  crypto_uint64 sum = 0;
+  crypto_uint64 delta = 0x9e3779b97f4a7c15;
+  int i;
+  for (i = 0;i < 32;++i) {
+    sum += delta;
+    v0 += ((v1<<7) + k0) ^ (v1 + sum) ^ ((v1>>12) + k1);
+    v1 += ((v0<<16) + k2) ^ (v0 + sum) ^ ((v0>>8) + k3);
+  }
+  uint64_pack(out + 0,v0);
+  uint64_pack(out + 8,v1);
+  return 0;
+}