Merge GH #489 Add support probabilistic DSA & ECDSA

4 files changed, 23 insertions, 11 deletions

diff --git a/src/lib/pubkey/dsa/dsa.cpp b/src/lib/pubkey/dsa/dsa.cpp
index 471189cd8..c7d44c73a 100644
--- a/src/lib/pubkey/dsa/dsa.cpp
+++ b/src/lib/pubkey/dsa/dsa.cpp
@@ -1,6 +1,7 @@
 /*
 * DSA
 * (C) 1999-2010,2014 Jack Lloyd
+* (C) 2016 René Korthaus
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -10,7 +11,9 @@
 #include <botan/keypair.h>
 #include <botan/pow_mod.h>
 #include <botan/reducer.h>
-#include <botan/rfc6979.h>
+#if defined(BOTAN_HAS_RFC6979_GENERATOR)
+  #include <botan/rfc6979.h>
+#endif
 #include <future>
 
 namespace Botan {
@@ -84,7 +87,7 @@ class DSA_Signature_Operation : public PK_Ops::Signature_with_EMSA
          m_x(dsa.get_x()),
          m_powermod_g_p(dsa.group_g(), dsa.group_p()),
          m_mod_q(dsa.group_q()),
-         m_hash(hash_for_deterministic_signature(emsa))
+         m_emsa(emsa)
          {
          }
 
@@ -99,19 +102,23 @@ class DSA_Signature_Operation : public PK_Ops::Signature_with_EMSA
       const BigInt& m_x;
       Fixed_Base_Power_Mod m_powermod_g_p;
       Modular_Reducer m_mod_q;
-      std::string m_hash;
+      std::string m_emsa;
    };
 
 secure_vector<byte>
 DSA_Signature_Operation::raw_sign(const byte msg[], size_t msg_len,
-                                  RandomNumberGenerator&)
+                                  RandomNumberGenerator& rng)
    {
    BigInt i(msg, msg_len);
 
    while(i >= m_q)
       i -= m_q;
 
-   const BigInt k = generate_rfc6979_nonce(m_x, m_q, i, m_hash);
+#if defined(BOTAN_HAS_RFC6979_GENERATOR)
+   const BigInt k = generate_rfc6979_nonce(m_x, m_q, i, hash_for_deterministic_signature(m_emsa));
+#else
+   const BigInt k = BigInt::random_integer(rng, 1, m_q);
+#endif
 
    auto future_r = std::async(std::launch::async,
                               [&]() { return m_mod_q.reduce(m_powermod_g_p(k)); });
diff --git a/src/lib/pubkey/dsa/info.txt b/src/lib/pubkey/dsa/info.txt
index 6e0259ce2..94802ed59 100644
--- a/src/lib/pubkey/dsa/info.txt
+++ b/src/lib/pubkey/dsa/info.txt
@@ -5,5 +5,4 @@ dl_algo
 dl_group
 keypair
 numbertheory
-rfc6979
 </requires>
diff --git a/src/lib/pubkey/ecdsa/ecdsa.cpp b/src/lib/pubkey/ecdsa/ecdsa.cpp
index 4a4b0c037..53b5982e0 100644
--- a/src/lib/pubkey/ecdsa/ecdsa.cpp
+++ b/src/lib/pubkey/ecdsa/ecdsa.cpp
@@ -3,6 +3,7 @@
 * (C) 2007 Manuel Hartl, FlexSecure GmbH
 *     2007 Falko Strenzke, FlexSecure GmbH
 *     2008-2010,2015 Jack Lloyd
+*     2016 René Korthaus
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -10,7 +11,9 @@
 #include <botan/internal/pk_utils.h>
 #include <botan/ecdsa.h>
 #include <botan/keypair.h>
-#include <botan/rfc6979.h>
+#if defined(BOTAN_HAS_RFC6979_GENERATOR)
+  #include <botan/rfc6979.h>
+#endif
 
 namespace Botan {
 
@@ -43,7 +46,7 @@ class ECDSA_Signature_Operation : public PK_Ops::Signature_with_EMSA
          m_base_point(ecdsa.domain().get_base_point(), m_order),
          m_x(ecdsa.private_value()),
          m_mod_order(m_order),
-         m_hash(hash_for_deterministic_signature(emsa))
+         m_emsa(emsa)
          {
          }
 
@@ -59,7 +62,7 @@ class ECDSA_Signature_Operation : public PK_Ops::Signature_with_EMSA
       Blinded_Point_Multiply m_base_point;
       const BigInt& m_x;
       Modular_Reducer m_mod_order;
-      std::string m_hash;
+      std::string m_emsa;
    };
 
 secure_vector<byte>
@@ -68,7 +71,11 @@ ECDSA_Signature_Operation::raw_sign(const byte msg[], size_t msg_len,
    {
    const BigInt m(msg, msg_len);
 
-   const BigInt k = generate_rfc6979_nonce(m_x, m_order, m, m_hash);
+#if defined(BOTAN_HAS_RFC6979_GENERATOR)
+   const BigInt k = generate_rfc6979_nonce(m_x, m_order, m, hash_for_deterministic_signature(m_emsa));
+#else
+   const BigInt k = BigInt::random_integer(rng, 1, m_order);
+#endif
 
    const PointGFp k_times_P = m_base_point.blinded_multiply(k, rng);
    const BigInt r = m_mod_order.reduce(k_times_P.get_affine_x());
diff --git a/src/lib/pubkey/ecdsa/info.txt b/src/lib/pubkey/ecdsa/info.txt
index e7941d53d..e98913897 100644
--- a/src/lib/pubkey/ecdsa/info.txt
+++ b/src/lib/pubkey/ecdsa/info.txt
@@ -7,5 +7,4 @@ ecc_key
 keypair
 numbertheory
 rng
-rfc6979
 </requires>