Move last pieces of algorithm-specific code from general 'pubkey' module

into algorithm-specific directories. (Dependencies still remain on these
in core/libstate, though).

4 files changed, 142 insertions, 9 deletions

diff --git a/src/pubkey/dsa/dsa_core.h b/src/pubkey/dsa/dsa_core.h
index 467f3c23f..d1aa413e5 100644
--- a/src/pubkey/dsa/dsa_core.h
+++ b/src/pubkey/dsa/dsa_core.h
@@ -6,8 +6,7 @@
 #ifndef BOTAN_DSA_CORE_H__
 #define BOTAN_DSA_CORE_H__
 
-#include <botan/bigint.h>
-#include <botan/pk_ops.h>
+#include <botan/dsa_op.h>
 #include <botan/dl_group.h>
 
 namespace Botan {
diff --git a/src/pubkey/dsa/dsa_op.cpp b/src/pubkey/dsa/dsa_op.cpp
new file mode 100644
index 000000000..8b6e5403b
--- /dev/null
+++ b/src/pubkey/dsa/dsa_op.cpp
@@ -0,0 +1,81 @@
+/*************************************************
+* DSA Operations Source File                     *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/dsa_op.h>
+#include <botan/eng_def.h>
+
+namespace Botan {
+
+/*************************************************
+* Default_DSA_Op Constructor                     *
+*************************************************/
+Default_DSA_Op::Default_DSA_Op(const DL_Group& grp, const BigInt& y1,
+                               const BigInt& x1) : x(x1), y(y1), group(grp)
+   {
+   powermod_g_p = Fixed_Base_Power_Mod(group.get_g(), group.get_p());
+   powermod_y_p = Fixed_Base_Power_Mod(y, group.get_p());
+   mod_p = Modular_Reducer(group.get_p());
+   mod_q = Modular_Reducer(group.get_q());
+   }
+
+/*************************************************
+* Default DSA Verify Operation                   *
+*************************************************/
+bool Default_DSA_Op::verify(const byte msg[], u32bit msg_len,
+                            const byte sig[], u32bit sig_len) const
+   {
+   const BigInt& q = group.get_q();
+
+   if(sig_len != 2*q.bytes() || msg_len > q.bytes())
+      return false;
+
+   BigInt r(sig, q.bytes());
+   BigInt s(sig + q.bytes(), q.bytes());
+   BigInt i(msg, msg_len);
+
+   if(r <= 0 || r >= q || s <= 0 || s >= q)
+      return false;
+
+   s = inverse_mod(s, q);
+   s = mod_p.multiply(powermod_g_p(mod_q.multiply(s, i)),
+                      powermod_y_p(mod_q.multiply(s, r)));
+
+   return (mod_q.reduce(s) == r);
+   }
+
+/*************************************************
+* Default DSA Sign Operation                     *
+*************************************************/
+SecureVector<byte> Default_DSA_Op::sign(const byte in[], u32bit length,
+                                        const BigInt& k) const
+   {
+   if(x == 0)
+      throw Internal_Error("Default_DSA_Op::sign: No private key");
+
+   const BigInt& q = group.get_q();
+   BigInt i(in, length);
+
+   BigInt r = mod_q.reduce(powermod_g_p(k));
+   BigInt s = mod_q.multiply(inverse_mod(k, q), mul_add(x, r, i));
+
+   if(r.is_zero() || s.is_zero())
+      throw Internal_Error("Default_DSA_Op::sign: r or s was zero");
+
+   SecureVector<byte> output(2*q.bytes());
+   r.binary_encode(output + (output.size() / 2 - r.bytes()));
+   s.binary_encode(output + (output.size() - s.bytes()));
+   return output;
+   }
+
+/*************************************************
+* Acquire a DSA op                               *
+*************************************************/
+DSA_Operation* Default_Engine::dsa_op(const DL_Group& group, const BigInt& y,
+                                      const BigInt& x) const
+   {
+   return new Default_DSA_Op(group, y, x);
+   }
+
+}
diff --git a/src/pubkey/dsa/dsa_op.h b/src/pubkey/dsa/dsa_op.h
new file mode 100644
index 000000000..98e671bf0
--- /dev/null
+++ b/src/pubkey/dsa/dsa_op.h
@@ -0,0 +1,51 @@
+/*************************************************
+* DSA Operations Header File                     *
+* (C) 1999-2008 Jack Lloyd                       *
+*************************************************/
+
+#ifndef BOTAN_DSA_OPS_H__
+#define BOTAN_DSA_OPS_H__
+
+#include <botan/numthry.h>
+#include <botan/pow_mod.h>
+#include <botan/reducer.h>
+#include <botan/dl_group.h>
+
+namespace Botan {
+
+/*************************************************
+* DSA Operation                                  *
+*************************************************/
+class BOTAN_DLL DSA_Operation
+   {
+   public:
+      virtual bool verify(const byte[], u32bit,
+                          const byte[], u32bit) const = 0;
+      virtual SecureVector<byte> sign(const byte[], u32bit,
+                                      const BigInt&) const = 0;
+      virtual DSA_Operation* clone() const = 0;
+      virtual ~DSA_Operation() {}
+   };
+
+/*************************************************
+* Botan's Default DSA Operation                  *
+*************************************************/
+class BOTAN_DLL Default_DSA_Op : public DSA_Operation
+   {
+   public:
+      bool verify(const byte[], u32bit, const byte[], u32bit) const;
+      SecureVector<byte> sign(const byte[], u32bit, const BigInt&) const;
+
+      DSA_Operation* clone() const { return new Default_DSA_Op(*this); }
+
+      Default_DSA_Op(const DL_Group&, const BigInt&, const BigInt&);
+   private:
+      const BigInt x, y;
+      const DL_Group group;
+      Fixed_Base_Power_Mod powermod_g_p, powermod_y_p;
+      Modular_Reducer mod_p, mod_q;
+   };
+
+}
+
+#endif
diff --git a/src/pubkey/dsa/info.txt b/src/pubkey/dsa/info.txt
index e98f33ca9..f1b505800 100644
--- a/src/pubkey/dsa/info.txt
+++ b/src/pubkey/dsa/info.txt
@@ -4,13 +4,6 @@ define DSA
 
 load_on auto
 
-<add>
-dsa.cpp
-dsa.h
-dsa_core.cpp
-dsa_core.h
-</add>
-
 <requires>
 asn1
 bigint
@@ -19,3 +12,12 @@ keypair
 numbertheory
 pubkey
 </requires>
+
+<add>
+dsa.cpp
+dsa.h
+dsa_core.cpp
+dsa_core.h
+dsa_op.cpp
+dsa_op.h
+</add>