1 files changed, 105 insertions, 0 deletions
diff --git a/src/engine/gnump/gmp_nr.cpp b/src/engine/gnump/gmp_nr.cpp
new file mode 100644
index 000000000..97b7e5554
--- /dev/null
+++ b/src/engine/gnump/gmp_nr.cpp
@@ -0,0 +1,105 @@
+/*************************************************
+* GMP NR Engine Source File                      *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/eng_gmp.h>
+#include <botan/gmp_wrap.h>
+#include <gmp.h>
+
+namespace Botan {
+
+#if defined(BOTAN_HAS_NYBERG_RUEPPEL)
+
+namespace {
+
+/*************************************************
+* GMP NR Operation                               *
+*************************************************/
+class GMP_NR_Op : public NR_Operation
+   {
+   public:
+      SecureVector<byte> verify(const byte[], u32bit) const;
+      SecureVector<byte> sign(const byte[], u32bit, const BigInt&) const;
+
+      NR_Operation* clone() const { return new GMP_NR_Op(*this); }
+
+      GMP_NR_Op(const DL_Group& group, const BigInt& y1, const BigInt& x1) :
+         x(x1), y(y1), p(group.get_p()), q(group.get_q()), g(group.get_g()) {}
+   private:
+      const GMP_MPZ x, y, p, q, g;
+   };
+
+/*************************************************
+* GMP NR Verify Operation                        *
+*************************************************/
+SecureVector<byte> GMP_NR_Op::verify(const byte sig[], u32bit sig_len) const
+   {
+   const u32bit q_bytes = q.bytes();
+
+   if(sig_len != 2*q_bytes)
+      return false;
+
+   GMP_MPZ c(sig, q_bytes);
+   GMP_MPZ d(sig + q_bytes, q_bytes);
+
+   if(mpz_cmp_ui(c.value, 0) <= 0 || mpz_cmp(c.value, q.value) >= 0 ||
+                                     mpz_cmp(d.value, q.value) >= 0)
+      throw Invalid_Argument("GMP_NR_Op::verify: Invalid signature");
+
+   GMP_MPZ i1, i2;
+   mpz_powm(i1.value, g.value, d.value, p.value);
+   mpz_powm(i2.value, y.value, c.value, p.value);
+   mpz_mul(i1.value, i1.value, i2.value);
+   mpz_mod(i1.value, i1.value, p.value);
+   mpz_sub(i1.value, c.value, i1.value);
+   mpz_mod(i1.value, i1.value, q.value);
+   return BigInt::encode(i1.to_bigint());
+   }
+
+/*************************************************
+* GMP NR Sign Operation                          *
+*************************************************/
+SecureVector<byte> GMP_NR_Op::sign(const byte in[], u32bit length,
+                                    const BigInt& k_bn) const
+   {
+   if(mpz_cmp_ui(x.value, 0) == 0)
+      throw Internal_Error("GMP_NR_Op::sign: No private key");
+
+   GMP_MPZ f(in, length);
+   GMP_MPZ k(k_bn);
+
+   if(mpz_cmp(f.value, q.value) >= 0)
+      throw Invalid_Argument("GMP_NR_Op::sign: Input is out of range");
+
+   GMP_MPZ c, d;
+   mpz_powm(c.value, g.value, k.value, p.value);
+   mpz_add(c.value, c.value, f.value);
+   mpz_mod(c.value, c.value, q.value);
+   mpz_mul(d.value, x.value, c.value);
+   mpz_sub(d.value, k.value, d.value);
+   mpz_mod(d.value, d.value, q.value);
+
+   if(mpz_cmp_ui(c.value, 0) == 0)
+      throw Internal_Error("Default_NR_Op::sign: c was zero");
+
+   const u32bit q_bytes = q.bytes();
+   SecureVector<byte> output(2*q_bytes);
+   c.encode(output, q_bytes);
+   d.encode(output + q_bytes, q_bytes);
+   return output;
+   }
+
+}
+
+/*************************************************
+* Acquire a NR op                                *
+*************************************************/
+NR_Operation* GMP_Engine::nr_op(const DL_Group& group, const BigInt& y,
+                                const BigInt& x) const
+   {
+   return new GMP_NR_Op(group, y, x);
+   }
+#endif
+
+}