1 files changed, 137 insertions, 0 deletions
diff --git a/ltc_prng.c b/ltc_prng.c
new file mode 100644
index 0000000..11e95d6
--- /dev/null
+++ b/ltc_prng.c
@@ -0,0 +1,137 @@
+/* Copied from libtomcrypt/src/prngs/sprng.c and modified to
+ * use Dropbear's genrandom(). */
+
+/* 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.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+#include "options.h"
+#include "includes.h"
+#include "random.h"
+#include "ltc_prng.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 DROPBEAR_LTC_PRNG
+
+/**
+  Start the PRNG
+  @param prng     [out] The PRNG state to initialize
+  @return CRYPT_OK if successful
+*/  
+int dropbear_prng_start(prng_state* UNUSED(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 dropbear_prng_add_entropy(const unsigned char* UNUSED(in), unsigned long UNUSED(inlen), prng_state* UNUSED(prng))
+{
+   return CRYPT_OK;
+}
+
+/**
+  Make the PRNG ready to read from
+  @param prng   The PRNG to make active
+  @return CRYPT_OK if successful
+*/  
+int dropbear_prng_ready(prng_state* UNUSED(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 dropbear_prng_read(unsigned char* out, unsigned long outlen, prng_state* UNUSED(prng))
+{
+   LTC_ARGCHK(out != NULL);
+   genrandom(out, outlen);
+   return outlen;
+}
+
+/**
+  Terminate the PRNG
+  @param prng   The PRNG to terminate
+  @return CRYPT_OK if successful
+*/  
+int dropbear_prng_done(prng_state* UNUSED(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 dropbear_prng_export(unsigned char* UNUSED(out), unsigned long* outlen, prng_state* UNUSED(prng))
+{
+   LTC_ARGCHK(outlen != NULL);
+
+   *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 dropbear_prng_import(const unsigned char* UNUSED(in), unsigned long UNUSED(inlen), prng_state* UNUSED(prng))
+{
+   return CRYPT_OK;
+}
+
+/**
+  PRNG self-test
+  @return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled
+*/  
+int dropbear_prng_test(void)
+{
+   return CRYPT_OK;
+}
+
+const struct ltc_prng_descriptor dropbear_prng_desc =
+{
+    "dropbear_prng", 0,
+    &dropbear_prng_start,
+    &dropbear_prng_add_entropy,
+    &dropbear_prng_ready,
+    &dropbear_prng_read,
+    &dropbear_prng_done,
+    &dropbear_prng_export,
+    &dropbear_prng_import,
+    &dropbear_prng_test
+};
+
+
+#endif // DROPBEAR_LTC_PRNG