1 files changed, 161 insertions, 0 deletions
diff --git a/src/ltc/prngs/sprng.c b/src/ltc/prngs/sprng.c
new file mode 100644
index 00000000..7e1865f4
--- /dev/null
+++ b/src/ltc/prngs/sprng.c
@@ -0,0 +1,161 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+#include "tomcrypt.h"
+
+/**
+   @file sprng.c
+   Secure PRNG, Tom St Denis
+*/
+
+/* A secure PRNG using the RNG functions.  Basically this is a
+ * wrapper that allows you to use a secure RNG as a PRNG
+ * in the various other functions.
+ */
+
+#ifdef LTC_SPRNG
+
+const struct ltc_prng_descriptor sprng_desc =
+{
+    "sprng", 0,
+    &sprng_start,
+    &sprng_add_entropy,
+    &sprng_ready,
+    &sprng_read,
+    &sprng_done,
+    &sprng_export,
+    &sprng_import,
+    &sprng_test
+};
+
+/**
+  Start the PRNG
+  @param prng     [out] The PRNG state to initialize
+  @return CRYPT_OK if successful
+*/
+int sprng_start(prng_state *prng)
+{
+   LTC_UNUSED_PARAM(prng);
+   return CRYPT_OK;
+}
+
+/**
+  Add entropy to the PRNG state
+  @param in       The data to add
+  @param inlen    Length of the data to add
+  @param prng     PRNG state to update
+  @return CRYPT_OK if successful
+*/
+int sprng_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng)
+{
+   LTC_UNUSED_PARAM(in);
+   LTC_UNUSED_PARAM(inlen);
+   LTC_UNUSED_PARAM(prng);
+   return CRYPT_OK;
+}
+
+/**
+  Make the PRNG ready to read from
+  @param prng   The PRNG to make active
+  @return CRYPT_OK if successful
+*/
+int sprng_ready(prng_state *prng)
+{
+   LTC_UNUSED_PARAM(prng);
+   return CRYPT_OK;
+}
+
+/**
+  Read from the PRNG
+  @param out      Destination
+  @param outlen   Length of output
+  @param prng     The active PRNG to read from
+  @return Number of octets read
+*/
+unsigned long sprng_read(unsigned char *out, unsigned long outlen, prng_state *prng)
+{
+   LTC_ARGCHK(out != NULL);
+   LTC_UNUSED_PARAM(prng);
+   return rng_get_bytes(out, outlen, NULL);
+}
+
+/**
+  Terminate the PRNG
+  @param prng   The PRNG to terminate
+  @return CRYPT_OK if successful
+*/
+int sprng_done(prng_state *prng)
+{
+   LTC_UNUSED_PARAM(prng);
+   return CRYPT_OK;
+}
+
+/**
+  Export the PRNG state
+  @param out       [out] Destination
+  @param outlen    [in/out] Max size and resulting size of the state
+  @param prng      The PRNG to export
+  @return CRYPT_OK if successful
+*/
+int sprng_export(unsigned char *out, unsigned long *outlen, prng_state *prng)
+{
+   LTC_ARGCHK(outlen != NULL);
+   LTC_UNUSED_PARAM(out);
+   LTC_UNUSED_PARAM(prng);
+
+   *outlen = 0;
+   return CRYPT_OK;
+}
+
+/**
+  Import a PRNG state
+  @param in       The PRNG state
+  @param inlen    Size of the state
+  @param prng     The PRNG to import
+  @return CRYPT_OK if successful
+*/
+int sprng_import(const unsigned char *in, unsigned long inlen, prng_state *prng)
+{
+  LTC_UNUSED_PARAM(in);
+  LTC_UNUSED_PARAM(inlen);
+  LTC_UNUSED_PARAM(prng);
+   return CRYPT_OK;
+}
+
+/**
+  PRNG self-test
+  @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled
+*/
+int sprng_test(void)
+{
+#ifndef LTC_TEST
+   return CRYPT_NOP;
+#else
+   prng_state st;
+   unsigned char en[] = { 0x01, 0x02, 0x03, 0x04 };
+   unsigned char out[1000];
+   int err;
+
+   if ((err = sprng_start(&st)) != CRYPT_OK)                         return err;
+   if ((err = sprng_add_entropy(en, sizeof(en), &st)) != CRYPT_OK)   return err;
+   if ((err = sprng_ready(&st)) != CRYPT_OK)                         return err;
+   if (sprng_read(out, 500, &st) != 500)                             return CRYPT_ERROR_READPRNG; /* skip 500 bytes */
+   if ((err = sprng_done(&st)) != CRYPT_OK)                          return err;
+
+   return CRYPT_OK;
+#endif
+}
+
+#endif
+
+
+
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */