1 files changed, 93 insertions, 0 deletions
diff --git a/csprng.c b/csprng.c
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+++ b/csprng.c
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+/* 
+ * csprng.c
+ * ------------------------------
+ *
+ * HAL interface to Cryptech CSPRNG/TRNG.
+ * 
+ * Authors: Joachim Strömbergson, Paul Selkirk, Rob Austein
+ * Copyright (c) 2014-2015, SUNET
+ * 
+ * Redistribution and use in source and binary forms, with or 
+ * without modification, are permitted provided that the following 
+ * conditions are met: 
+ * 
+ * 1. Redistributions of source code must retain the above copyright 
+ *    notice, this list of conditions and the following disclaimer. 
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright 
+ *    notice, this list of conditions and the following disclaimer in 
+ *    the documentation and/or other materials provided with the 
+ *    distribution. 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#if 0
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#endif
+
+#include "cryptech.h"
+
+#ifndef WAIT_FOR_CSPRNG_VALID
+#define WAIT_FOR_CSPRNG_VALID	1
+#endif
+
+hal_error_t hal_random(void *buffer, const size_t length)
+{
+  uint8_t temp[4], *buf = buffer;
+  hal_error_t err;
+  size_t i;
+
+  for (i = 0; i < length; i += 4) {
+    const int last = (length - i) < 4;
+
+    if (WAIT_FOR_CSPRNG_VALID && (err = hal_io_wait_valid(CSPRNG_ADDR_STATUS)) != HAL_OK)
+      return err;
+
+    if ((err = hal_io_read(CSPRNG_ADDR_RANDOM, (last ? temp : &buf[i]), 4)) != HAL_OK)
+      return err;
+
+    if (last)
+      for (; i < length; i++)
+        buf[i] = temp[i&3];
+  }
+
+  for (i = 0, buf = buffer; i < length; i++, buf++)
+    if (*buf != 0)
+      return HAL_OK;
+
+  return HAL_ERROR_CSPRNG_ZEROED;
+}
+
+/*
+ * "Any programmer who fails to comply with the standard naming, formatting,
+ *  or commenting conventions should be shot.  If it so happens that it is
+ *  inconvenient to shoot him, then he is to be politely requested to recode
+ *  his program in adherence to the above standard."
+ *                      -- Michael Spier, Digital Equipment Corporation
+ *
+ * Local variables:
+ * indent-tabs-mode: nil
+ * End:
+ */