Add rng command which can dump RNG outputs or raw entropy samples

3 files changed, 53 insertions, 0 deletions

diff --git a/src/cmd/apps.h b/src/cmd/apps.h
index 280ee46a0..d72220322 100644
--- a/src/cmd/apps.h
+++ b/src/cmd/apps.h
@@ -29,6 +29,7 @@ DEFINE_APP(cert_verify);
 DEFINE_APP(ocsp_check);
 DEFINE_APP(pkcs10);
 DEFINE_APP(read_ssh);
+DEFINE_APP(rng);
 DEFINE_APP(self_sig);
 DEFINE_APP(tls_client);
 DEFINE_APP(tls_server);
diff --git a/src/cmd/main.cpp b/src/cmd/main.cpp
index cd42658b9..92ecc051e 100644
--- a/src/cmd/main.cpp
+++ b/src/cmd/main.cpp
@@ -161,6 +161,7 @@ int main(int argc, char* argv[])
       CALL_APP(fpe);
       CALL_APP(hash);
       CALL_APP(keygen);
+      CALL_APP(rng);
       CALL_APP(read_ssh);
       CALL_APP(speed);
 
diff --git a/src/cmd/rng.cpp b/src/cmd/rng.cpp
new file mode 100644
index 000000000..e2a7a8270
--- /dev/null
+++ b/src/cmd/rng.cpp
@@ -0,0 +1,51 @@
+/*
+* (C) 2014 Jack Lloyd
+*
+* Distributed under the terms in doc/license.rst
+*/
+
+#include "apps.h"
+#include <botan/libstate.h>
+
+int rng_main(int argc, char* argv[])
+   {
+   if(argc == 1)
+      {
+      std::cout << "Usage: " << argv[0] << " [--raw-entropy] [n]\n";
+      return 1;
+      }
+
+   try
+      {
+      const size_t amt = to_u32bit(argv[argc-1]);
+      const bool raw = (argc == 3 && std::string(argv[1]) == "--raw-entropy");
+
+      if(!raw)
+         {
+         AutoSeeded_RNG rng;
+         std::cout << hex_encode(rng.random_vec(amt)) << "\n";
+         }
+      else
+         {
+         double total_collected = 0;
+
+         Entropy_Accumulator accum(
+            [amt,&total_collected](const byte in[], size_t in_len, double entropy_estimate)
+            {
+            std::cout << "Collected estimated "<< entropy_estimate << " bits in "
+                      << hex_encode(in, in_len) << "\n";
+            total_collected += entropy_estimate;
+            return total_collected >= amt;
+            });
+
+         global_state().poll_available_sources(accum);
+         }
+      }
+   catch(std::exception& e)
+      {
+      std::cout << "Error: " << e.what() << "\n";
+      return 1;
+      }
+
+   return 0;
+   }