Add Command::rng()

for when a command wants an RNG but doesn't much care what kind.

This adds a place where a future --rng-type= option can be consulted
to eg use the system RNG or a user seeded DRBG.

9 files changed, 42 insertions, 58 deletions

diff --git a/src/cli/bench.cpp b/src/cli/bench.cpp
index 1928b50d0..0d77ac2ec 100644
--- a/src/cli/bench.cpp
+++ b/src/cli/bench.cpp
@@ -17,7 +17,6 @@
 #include <botan/hash.h>
 #include <botan/mac.h>
 #include <botan/cipher_mode.h>
-#include <botan/auto_rng.h>
 
 #if defined(BOTAN_HAS_PUBLIC_KEY_CRYPTO)
   #include <botan/pkcs8.h>
@@ -339,9 +338,6 @@ class Benchmark : public Command
 
    private:
 
-      Botan::AutoSeeded_RNG m_rng;
-      Botan::RandomNumberGenerator& rng() { return m_rng; }
-
       template<typename T>
       using bench_fn = std::function<void (T&,
                                            std::string,
diff --git a/src/cli/cli.h b/src/cli/cli.h
index 85d6770ba..f55316b9d 100644
--- a/src/cli/cli.h
+++ b/src/cli/cli.h
@@ -10,6 +10,11 @@
 #include <botan/build.h>
 #include <botan/parsing.h>
 #include <botan/rng.h>
+#include <botan/auto_rng.h>
+
+#if defined(BOTAN_HAS_SYSTEM_RNG)
+  #include <botan/system_rng.h>
+#endif
 
 #include <fstream>
 #include <iostream>
@@ -445,6 +450,16 @@ class Command
          output().write(reinterpret_cast<const char*>(vec.data()), vec.size());
          }
 
+      Botan::RandomNumberGenerator& rng()
+         {
+         if(m_rng == nullptr)
+            {
+            m_rng.reset(new Botan::AutoSeeded_RNG);
+            }
+
+         return *m_rng;
+         }
+
    private:
       // set in constructor
       std::string m_spec;
@@ -463,6 +478,7 @@ class Command
       std::unique_ptr<std::ofstream> m_output_stream;
       std::unique_ptr<std::ofstream> m_error_output_stream;
 
+      std::unique_ptr<Botan::RandomNumberGenerator> m_rng;
 
    public:
       // the registry interface:
diff --git a/src/cli/math.cpp b/src/cli/math.cpp
index c6f40e785..07b809d19 100644
--- a/src/cli/math.cpp
+++ b/src/cli/math.cpp
@@ -10,7 +10,6 @@
 
 #include <botan/reducer.h>
 #include <botan/numthry.h>
-#include <botan/auto_rng.h>
 #include <iterator>
 
 namespace Botan_CLI {
@@ -22,14 +21,12 @@ class Gen_Prime : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          const size_t bits = get_arg_sz("bits");
          const size_t cnt = get_arg_sz("count");
 
          for(size_t i = 0; i != cnt; ++i)
             {
-            const Botan::BigInt p = Botan::random_prime(rng, bits);
+            const Botan::BigInt p = Botan::random_prime(rng(), bits);
             output() << p << "\n";
             }
          }
@@ -46,8 +43,7 @@ class Is_Prime : public Command
          {
          Botan::BigInt n(get_arg("n"));
          const size_t prob = get_arg_sz("prob");
-         Botan::AutoSeeded_RNG rng;
-         const bool prime = Botan::is_prime(n, rng, prob);
+         const bool prime = Botan::is_prime(n, rng(), prob);
 
          output() << n << " is " << (prime ? "probably prime" : "composite") << "\n";
          }
@@ -68,9 +64,7 @@ class Factor : public Command
          {
          Botan::BigInt n(get_arg("n"));
 
-         Botan::AutoSeeded_RNG rng;
-
-         std::vector<Botan::BigInt> factors = factorize(n, rng);
+         std::vector<Botan::BigInt> factors = factorize(n, rng());
          std::sort(factors.begin(), factors.end());
 
          output() << n << ": ";
diff --git a/src/cli/pubkey.cpp b/src/cli/pubkey.cpp
index 2616f6065..fcda6d21e 100644
--- a/src/cli/pubkey.cpp
+++ b/src/cli/pubkey.cpp
@@ -9,7 +9,6 @@
 
 #if defined(BOTAN_HAS_PUBLIC_KEY_CRYPTO)
 
-#include <botan/auto_rng.h>
 #include <botan/base64.h>
 
 #include <botan/pk_keys.h>
@@ -114,8 +113,7 @@ class PK_Keygen : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-         std::unique_ptr<Botan::Private_Key> key(do_keygen(get_arg("algo"), get_arg("params"), rng));
+         std::unique_ptr<Botan::Private_Key> key(do_keygen(get_arg("algo"), get_arg("params"), rng()));
 
          const std::string pass = get_arg("passphrase");
          const bool der_out = flag_set("der-out");
@@ -173,10 +171,8 @@ class PK_Sign : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          std::unique_ptr<Botan::Private_Key> key(Botan::PKCS8::load_key(get_arg("key"),
-                                                                        rng,
+                                                                        rng(),
                                                                         get_arg("passphrase")));
 
          if(!key)
@@ -234,20 +230,18 @@ class Gen_DL_Group : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          const size_t pbits = get_arg_sz("pbits");
 
          const std::string type = get_arg("type");
 
          if(type == "strong")
             {
-            Botan::DL_Group grp(rng, Botan::DL_Group::Strong, pbits);
+            Botan::DL_Group grp(rng(), Botan::DL_Group::Strong, pbits);
             output() << grp.PEM_encode(Botan::DL_Group::ANSI_X9_42);
             }
          else if(type == "subgroup")
             {
-            Botan::DL_Group grp(rng, Botan::DL_Group::Prime_Subgroup, pbits, get_arg_sz("qbits"));
+            Botan::DL_Group grp(rng(), Botan::DL_Group::Prime_Subgroup, pbits, get_arg_sz("qbits"));
             output() << grp.PEM_encode(Botan::DL_Group::ANSI_X9_42);
             }
          else
@@ -266,11 +260,9 @@ class PKCS8_Tool : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          std::unique_ptr<Botan::Private_Key> key(
             Botan::PKCS8::load_key(get_arg("key"),
-                                   rng,
+                                   rng(),
                                    get_arg("pass-in")));
 
          const std::chrono::milliseconds pbe_millis(get_arg_sz("pbe-millis"));
@@ -300,7 +292,7 @@ class PKCS8_Tool : public Command
                   }
                else
                   {
-                  write_output(Botan::PKCS8::BER_encode(*key, rng, pass, pbe_millis, pbe));
+                  write_output(Botan::PKCS8::BER_encode(*key, rng(), pass, pbe_millis, pbe));
                   }
                }
             else
@@ -311,7 +303,7 @@ class PKCS8_Tool : public Command
                   }
                else
                   {
-                  output() << Botan::PKCS8::PEM_encode(*key, rng, pass, pbe_millis, pbe);
+                  output() << Botan::PKCS8::PEM_encode(*key, rng(), pass, pbe_millis, pbe);
                   }
                }
             }
diff --git a/src/cli/tls_client.cpp b/src/cli/tls_client.cpp
index 1f69473c1..0d584dee0 100644
--- a/src/cli/tls_client.cpp
+++ b/src/cli/tls_client.cpp
@@ -9,7 +9,6 @@
 #if defined(BOTAN_HAS_TLS) && defined(BOTAN_TARGET_OS_HAS_SOCKETS)
 
 #include <botan/tls_client.h>
-#include <botan/auto_rng.h>
 #include <botan/hex.h>
 
 #if defined(BOTAN_HAS_TLS_SQLITE3_SESSION_MANAGER)
@@ -44,7 +43,6 @@ class TLS_Client : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
          Botan::TLS::Policy policy; // TODO read from a file
 
          // TODO client cert auth
@@ -57,12 +55,12 @@ class TLS_Client : public Command
 
          if(!sessions_db.empty())
             {
-            session_mgr.reset(new Botan::TLS::Session_Manager_SQLite(sessions_passphrase, rng, sessions_db));
+            session_mgr.reset(new Botan::TLS::Session_Manager_SQLite(sessions_passphrase, rng(), sessions_db));
             }
 #endif
          if(!session_mgr)
             {
-            session_mgr.reset(new Botan::TLS::Session_Manager_In_Memory(rng));
+            session_mgr.reset(new Botan::TLS::Session_Manager_In_Memory(rng()));
             }
 
          Basic_Credentials_Manager creds;
@@ -96,7 +94,7 @@ class TLS_Client : public Command
                                    *session_mgr,
                                    creds,
                                    policy,
-                                   rng,
+                                   rng(),
                                    Botan::TLS::Server_Information(host, port),
                                    version,
                                    protocols_to_offer);
diff --git a/src/cli/tls_proxy.cpp b/src/cli/tls_proxy.cpp
index e28ef14bc..1457700cf 100644
--- a/src/cli/tls_proxy.cpp
+++ b/src/cli/tls_proxy.cpp
@@ -401,8 +401,7 @@ class TLS_Proxy : public Command
 
          const size_t num_threads = get_arg_sz("threads") || std::thread::hardware_concurrency() || 2;
 
-         Botan::AutoSeeded_RNG rng;
-         Basic_Credentials_Manager creds(rng, server_crt, server_key);
+         Basic_Credentials_Manager creds(rng(), server_crt, server_key);
 
          Botan::TLS::Policy policy; // TODO: Read policy from text file
 
@@ -419,12 +418,12 @@ class TLS_Proxy : public Command
 
          if(!sessions_db.empty())
             {
-            session_mgr.reset(new Botan::TLS::Session_Manager_SQLite(sessions_passphrase, rng, sessions_db));
+            session_mgr.reset(new Botan::TLS::Session_Manager_SQLite(sessions_passphrase, rng(), sessions_db));
             }
 #endif
          if(!session_mgr)
             {
-            session_mgr.reset(new Botan::TLS::Session_Manager_In_Memory(rng));
+            session_mgr.reset(new Botan::TLS::Session_Manager_In_Memory(rng()));
             }
 
          tls_proxy_server server(io, listen_port, server_endpoint_iterator, creds, policy, *session_mgr);
diff --git a/src/cli/tls_server.cpp b/src/cli/tls_server.cpp
index f6a3a311e..f83f008f7 100644
--- a/src/cli/tls_server.cpp
+++ b/src/cli/tls_server.cpp
@@ -11,7 +11,6 @@
 
 #include <botan/tls_server.h>
 #include <botan/hex.h>
-#include <botan/auto_rng.h>
 #include "credentials.h"
 
 #include <list>
@@ -48,13 +47,11 @@ class TLS_Server : public Command
 
          const bool is_tcp = (transport == "tcp");
 
-         Botan::AutoSeeded_RNG rng;
-
          Botan::TLS::Policy policy; // TODO read policy from file
 
-         Botan::TLS::Session_Manager_In_Memory session_manager(rng); // TODO sqlite3
+         Botan::TLS::Session_Manager_In_Memory session_manager(rng()); // TODO sqlite3
 
-         Basic_Credentials_Manager creds(rng, server_crt, server_key);
+         Basic_Credentials_Manager creds(rng(), server_crt, server_key);
 
          auto protocol_chooser = [](const std::vector<std::string>& protocols) -> std::string {
             for(size_t i = 0; i != protocols.size(); ++i)
@@ -116,7 +113,7 @@ class TLS_Server : public Command
                                       session_manager,
                                       creds,
                                       policy,
-                                      rng,
+                                      rng(),
                                       protocol_chooser,
                                       !is_tcp);
 
diff --git a/src/cli/utils.cpp b/src/cli/utils.cpp
index 9302ec5d0..ac2d62396 100644
--- a/src/cli/utils.cpp
+++ b/src/cli/utils.cpp
@@ -235,8 +235,7 @@ class Generate_Bcrypt : public Command
          const std::string password = get_arg("password");
          const size_t wf = get_arg_sz("work_factor");
 
-         Botan::AutoSeeded_RNG rng;
-         output() << Botan::generate_bcrypt(password, rng, wf) << "\n";
+         output() << Botan::generate_bcrypt(password, rng(), wf) << "\n";
          }
    };
 
diff --git a/src/cli/x509.cpp b/src/cli/x509.cpp
index add73a466..7cac858a7 100644
--- a/src/cli/x509.cpp
+++ b/src/cli/x509.cpp
@@ -8,7 +8,6 @@
 
 #if defined(BOTAN_HAS_X509_CERTIFICATES)
 
-#include <botan/auto_rng.h>
 #include <botan/certstor.h>
 #include <botan/pkcs8.h>
 #include <botan/x509_ca.h>
@@ -30,13 +29,11 @@ class Sign_Cert : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          Botan::X509_Certificate ca_cert(get_arg("ca_cert"));
 
          std::unique_ptr<Botan::PKCS8_PrivateKey> key(
             Botan::PKCS8::load_key(get_arg("ca_key"),
-                                   rng,
+                                   rng(),
                                    get_arg("ca_key_pass")));
 
          if(!key)
@@ -54,7 +51,7 @@ class Sign_Cert : public Command
 
          Botan::X509_Time end_time(now + days(get_arg_sz("duration")));
 
-         Botan::X509_Certificate new_cert = ca.sign_request(req, rng,
+         Botan::X509_Certificate new_cert = ca.sign_request(req, rng(),
                                                             start_time, end_time);
 
          output() << new_cert.PEM_encode();
@@ -153,11 +150,9 @@ class Gen_Self_Signed : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          std::unique_ptr<Botan::Private_Key> key(
             Botan::PKCS8::load_key(get_arg("key"),
-                                   rng,
+                                   rng(),
                                    get_arg("key-pass")));
 
          if(!key)
@@ -175,7 +170,7 @@ class Gen_Self_Signed : public Command
             opts.CA_key();
 
          Botan::X509_Certificate cert =
-            Botan::X509::create_self_signed_cert(opts, *key, get_arg("hash"), rng);
+            Botan::X509::create_self_signed_cert(opts, *key, get_arg("hash"), rng());
 
          output() << cert.PEM_encode();
          }
@@ -191,11 +186,9 @@ class Generate_PKCS10 : public Command
 
       void go() override
          {
-         Botan::AutoSeeded_RNG rng;
-
          std::unique_ptr<Botan::Private_Key> key(
             Botan::PKCS8::load_key(get_arg("key"),
-                                   rng,
+                                   rng(),
                                    get_arg("key-pass")));
 
          if(!key)
@@ -211,7 +204,7 @@ class Generate_PKCS10 : public Command
          Botan::PKCS10_Request req =
             Botan::X509::create_cert_req(opts, *key,
                                          get_arg("hash"),
-                                         rng);
+                                         rng());
 
          output() << req.PEM_encode();
          }