Add prime and dl_group command line tools.

Some cleanups in random_prime. Increase probability in prime tests from
1/2**64 to 1/2**128. Also break out of the sieve loop early if it has
failed.

2 files changed, 133 insertions, 0 deletions

diff --git a/src/cmd/dl_group.cpp b/src/cmd/dl_group.cpp
new file mode 100644
index 000000000..2db65ded2
--- /dev/null
+++ b/src/cmd/dl_group.cpp
@@ -0,0 +1,85 @@
+/*
+* (C) 2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include "apps.h"
+
+#if defined(BOTAN_HAS_DL_GROUP)
+
+#include <botan/dl_group.h>
+#include <fstream>
+
+namespace {
+
+std::string read_file_contents(const std::string& filename)
+   {
+   std::ifstream in(filename.c_str());
+   if(!in.good())
+      throw std::runtime_error("Failure reading " + filename);
+
+   std::vector<std::string> contents;
+   size_t total_size = 0;
+   while(in.good())
+      {
+      std::string line;
+      std::getline(in, line);
+      total_size += line.size();
+      contents.push_back(std::move(line));
+      }
+
+   std::string res;
+   contents.reserve(total_size);
+   for(auto&& line : contents)
+      res += line;
+   return res;
+   }
+
+int dl_group(int argc, char* argv[])
+   {
+   if(argc < 2)
+      {
+      std::cout << "Usage: " << argv[0] << " [create bits|info file]" << std::endl;
+      return 1;
+      }
+
+   const std::string cmd = argv[1];
+
+   if(cmd == "create")
+      {
+      AutoSeeded_RNG rng;
+      const size_t bits = to_u32bit(argv[2]);
+
+      const DL_Group::PrimeType prime_type = DL_Group::Strong;
+      //const DL_Group::PrimeType prime_type = DL_Group::Prime_Subgroup;
+
+      DL_Group grp(rng, prime_type, bits);
+
+      std::cout << grp.PEM_encode(DL_Group::DSA_PARAMETERS);
+      }
+   else if(cmd == "info")
+      {
+      DL_Group grp;
+      std::string pem = read_file_contents(argv[2]);
+      std::cout << pem << "\n";
+
+      std::cout << "DL_Group " << grp.get_p().bits() << " bits\n";
+      std::cout << "p=" << grp.get_p() << "\n";
+      std::cout << "q=" << grp.get_q() << "\n";
+      std::cout << "g=" << grp.get_g() << "\n";
+      }
+   else
+      {
+      std::cout << "ERROR: Unknown command\n";
+      return 1;
+      }
+
+   return 0;
+   }
+
+REGISTER_APP(dl_group);
+
+}
+
+#endif
diff --git a/src/cmd/prime.cpp b/src/cmd/prime.cpp
new file mode 100644
index 000000000..61f535dd7
--- /dev/null
+++ b/src/cmd/prime.cpp
@@ -0,0 +1,48 @@
+/*
+* (C) 2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include "apps.h"
+
+#if defined(BOTAN_HAS_NUMBERTHEORY)
+
+#include <botan/numthry.h>
+
+#include <algorithm>
+#include <iostream>
+
+namespace {
+
+int prime(int argc, char* argv[])
+   {
+   if(argc < 2)
+      {
+      std::cout << "Usage: " << argv[0] << " bits count" << std::endl;
+      return 1;
+      }
+
+   AutoSeeded_RNG rng;
+   const size_t bits = to_u32bit(argv[1]);
+   const size_t cnt = argv[2] != nullptr ? to_u32bit(argv[2]) : 1;
+
+   for(size_t i = 0; i != cnt; ++i)
+      {
+      const BigInt p = random_prime(rng, bits);
+      std::cout << p << "\n";
+
+      if(p.bits() != bits)
+         {
+         std::cout << "Result not exactly requested bit size, got " << p.bits() << "\n";
+         }
+      }
+
+   return 0;
+   }
+
+}
+
+REGISTER_APP(prime);
+
+#endif