1 files changed, 126 insertions, 0 deletions
diff --git a/old/botan/src/engine/openssl/ossl_dsa.cpp b/old/botan/src/engine/openssl/ossl_dsa.cpp
new file mode 100644
index 0000000..bfffb87
--- /dev/null
+++ b/old/botan/src/engine/openssl/ossl_dsa.cpp
@@ -0,0 +1,126 @@
+/*
+* OpenSSL DSA Engine
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/eng_ossl.h>
+#include <botan/bn_wrap.h>
+#include <openssl/opensslv.h>
+
+#if OPENSSL_VERSION_NUMBER < 0x0090700F
+  #error Your OpenSSL install is too old, upgrade to 0.9.7 or later
+#endif
+
+namespace Botan {
+
+#if defined(BOTAN_HAS_DSA)
+
+namespace {
+
+/*
+* OpenSSL DSA Operation
+*/
+class OpenSSL_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 OpenSSL_DSA_Op(*this); }
+
+      OpenSSL_DSA_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 OSSL_BN x, y, p, q, g;
+      OSSL_BN_CTX ctx;
+   };
+
+/*
+* OpenSSL DSA Verify Operation
+*/
+bool OpenSSL_DSA_Op::verify(const byte msg[], u32bit msg_len,
+                            const byte sig[], u32bit sig_len) const
+   {
+   const u32bit q_bytes = q.bytes();
+
+   if(sig_len != 2*q_bytes || msg_len > q_bytes)
+      return false;
+
+   OSSL_BN r(sig, q_bytes);
+   OSSL_BN s(sig + q_bytes, q_bytes);
+   OSSL_BN i(msg, msg_len);
+
+   if(BN_is_zero(r.value) || BN_cmp(r.value, q.value) >= 0)
+      return false;
+   if(BN_is_zero(s.value) || BN_cmp(s.value, q.value) >= 0)
+      return false;
+
+   if(BN_mod_inverse(s.value, s.value, q.value, ctx.value) == 0)
+      return false;
+
+   OSSL_BN si;
+   BN_mod_mul(si.value, s.value, i.value, q.value, ctx.value);
+   BN_mod_exp(si.value, g.value, si.value, p.value, ctx.value);
+
+   OSSL_BN sr;
+   BN_mod_mul(sr.value, s.value, r.value, q.value, ctx.value);
+   BN_mod_exp(sr.value, y.value, sr.value, p.value, ctx.value);
+
+   BN_mod_mul(si.value, si.value, sr.value, p.value, ctx.value);
+   BN_nnmod(si.value, si.value, q.value, ctx.value);
+
+   if(BN_cmp(si.value, r.value) == 0)
+      return true;
+   return false;
+   }
+
+/*
+* OpenSSL DSA Sign Operation
+*/
+SecureVector<byte> OpenSSL_DSA_Op::sign(const byte in[], u32bit length,
+                                        const BigInt& k_bn) const
+   {
+   if(BN_is_zero(x.value))
+      throw Internal_Error("OpenSSL_DSA_Op::sign: No private key");
+
+   OSSL_BN i(in, length);
+   OSSL_BN k(k_bn);
+
+   OSSL_BN r;
+   BN_mod_exp(r.value, g.value, k.value, p.value, ctx.value);
+   BN_nnmod(r.value, r.value, q.value, ctx.value);
+
+   BN_mod_inverse(k.value, k.value, q.value, ctx.value);
+
+   OSSL_BN s;
+   BN_mul(s.value, x.value, r.value, ctx.value);
+   BN_add(s.value, s.value, i.value);
+   BN_mod_mul(s.value, s.value, k.value, q.value, ctx.value);
+
+   if(BN_is_zero(r.value) || BN_is_zero(s.value))
+      throw Internal_Error("OpenSSL_DSA_Op::sign: r or s was zero");
+
+   const u32bit q_bytes = q.bytes();
+
+   SecureVector<byte> output(2*q_bytes);
+   r.encode(output, q_bytes);
+   s.encode(output + q_bytes, q_bytes);
+   return output;
+   }
+
+}
+
+/*
+* Acquire a DSA op
+*/
+DSA_Operation* OpenSSL_Engine::dsa_op(const DL_Group& group, const BigInt& y,
+                                      const BigInt& x) const
+   {
+   return new OpenSSL_DSA_Op(group, y, x);
+   }
+#endif
+
+}