Moved salsa20_set_key to a separate file. Inlined salsa20_hash into salsa20_crypt.

1 files changed, 88 insertions, 0 deletions

diff --git a/salsa20-set-key.c b/salsa20-set-key.c
new file mode 100644
index 00000000..ecb0a213
--- /dev/null
+++ b/salsa20-set-key.c
@@ -0,0 +1,88 @@
+/* salsa20-set-key.c
+ *
+ * The Salsa20 stream cipher.
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2012 Simon Josefsson, Niels Möller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/* Based on:
+   salsa20-ref.c version 20051118
+   D. J. Bernstein
+   Public domain.
+*/
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+
+#include "salsa20.h"
+
+#include "macros.h"
+
+void
+salsa20_set_key(struct salsa20_ctx *ctx,
+		unsigned length, const uint8_t *key)
+{
+  static const uint32_t sigma[4] = {
+    /* "expand 32-byte k" */
+    0x61707865, 0x3320646e, 0x79622d32, 0x6b206574
+  };
+  static const uint32_t tau[4] = {
+    /* "expand 16-byte k" */
+    0x61707865, 0x3120646e, 0x79622d36, 0x6b206574
+  };
+  const uint32_t *constants;
+  
+  assert (length == SALSA20_MIN_KEY_SIZE || length == SALSA20_MAX_KEY_SIZE);
+
+  ctx->input[1] = LE_READ_UINT32(key + 0);
+  ctx->input[2] = LE_READ_UINT32(key + 4);
+  ctx->input[3] = LE_READ_UINT32(key + 8);
+  ctx->input[4] = LE_READ_UINT32(key + 12);
+  if (length == SALSA20_MAX_KEY_SIZE) { /* recommended */
+    ctx->input[11] = LE_READ_UINT32(key + 16);
+    ctx->input[12] = LE_READ_UINT32(key + 20);
+    ctx->input[13] = LE_READ_UINT32(key + 24);
+    ctx->input[14] = LE_READ_UINT32(key + 28);
+    constants = sigma;
+  } else { /* kbits == 128 */
+    ctx->input[11] = ctx->input[1];
+    ctx->input[12] = ctx->input[2];
+    ctx->input[13] = ctx->input[3];
+    ctx->input[14] = ctx->input[4];
+    constants = tau;
+  }
+  ctx->input[0]  = constants[0];
+  ctx->input[5]  = constants[1];
+  ctx->input[10] = constants[2];
+  ctx->input[15] = constants[3];
+}
+
+void
+salsa20_set_iv(struct salsa20_ctx *ctx, const uint8_t *iv)
+{
+  ctx->input[6] = LE_READ_UINT32(iv + 0);
+  ctx->input[7] = LE_READ_UINT32(iv + 4);
+  ctx->input[8] = 0;
+  ctx->input[9] = 0;
+}