merged

1 files changed, 277 insertions, 0 deletions

diff --git a/extra/yassl/taocrypt/src/dsa.cpp b/extra/yassl/taocrypt/src/dsa.cpp
new file mode 100644
index 00000000000..4716ebb22df
--- /dev/null
+++ b/extra/yassl/taocrypt/src/dsa.cpp
@@ -0,0 +1,277 @@
+/* dsa.cpp                                
+ *
+ * Copyright (C) 2003 Sawtooth Consulting Ltd.
+ *
+ * This file is part of yaSSL.
+ *
+ * yaSSL is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * yaSSL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+
+#include "runtime.hpp"
+#include "dsa.hpp"
+#include "sha.hpp"
+#include "asn.hpp"
+#include "modarith.hpp"
+#include "stdexcept.hpp"
+
+#include "algebra.cpp"   // for GCC 3.2 on aix ?
+
+
+namespace TaoCrypt {
+
+
+void DSA_PublicKey::Swap(DSA_PublicKey& other)
+{
+    p_.Swap(other.p_);
+    q_.Swap(other.q_);
+    g_.Swap(other.g_);
+    y_.Swap(other.y_);
+}
+
+
+DSA_PublicKey::DSA_PublicKey(const DSA_PublicKey& other)
+    : p_(other.p_), q_(other.q_), g_(other.g_), y_(other.y_)
+{}
+
+
+DSA_PublicKey& DSA_PublicKey::operator=(const DSA_PublicKey& that)
+{
+    DSA_PublicKey tmp(that);
+    Swap(tmp);
+    return *this;
+}
+
+
+DSA_PublicKey::DSA_PublicKey(Source& source)
+{
+    Initialize(source);
+}
+
+
+void DSA_PublicKey::Initialize(Source& source)
+{
+    DSA_Public_Decoder decoder(source);
+    decoder.Decode(*this);
+}
+
+
+void DSA_PublicKey::Initialize(const Integer& p, const Integer& q,
+                               const Integer& g, const Integer& y)
+{
+    p_ = p;
+    q_ = q;
+    g_ = g;
+    y_ = y;
+}
+   
+
+const Integer& DSA_PublicKey::GetModulus() const
+{
+    return p_;
+}
+
+const Integer& DSA_PublicKey::GetSubGroupOrder() const
+{
+    return q_;
+}
+
+
+const Integer& DSA_PublicKey::GetSubGroupGenerator() const
+{
+    return g_;
+}
+
+
+const Integer& DSA_PublicKey::GetPublicPart() const
+{
+    return y_;
+}
+
+
+void DSA_PublicKey::SetModulus(const Integer& p)
+{
+    p_ = p;
+}
+
+
+void DSA_PublicKey::SetSubGroupOrder(const Integer& q)
+{
+    q_ = q;
+}
+
+
+void DSA_PublicKey::SetSubGroupGenerator(const Integer& g)
+{
+    g_ = g;
+}
+
+
+void DSA_PublicKey::SetPublicPart(const Integer& y)
+{
+    y_ = y;
+}
+
+
+word32 DSA_PublicKey::SignatureLength() const
+{
+    return GetSubGroupOrder().ByteCount() * 2;  // r and s
+}
+
+
+
+DSA_PrivateKey::DSA_PrivateKey(Source& source)
+{
+    Initialize(source);
+}
+
+
+void DSA_PrivateKey::Initialize(Source& source)
+{
+    DSA_Private_Decoder decoder(source);
+    decoder.Decode(*this);
+}
+
+
+void DSA_PrivateKey::Initialize(const Integer& p, const Integer& q,
+                                const Integer& g, const Integer& y,
+                                const Integer& x)
+{
+    DSA_PublicKey::Initialize(p, q, g, y);
+    x_ = x;
+}
+
+
+const Integer& DSA_PrivateKey::GetPrivatePart() const
+{
+    return x_;
+}
+
+
+void DSA_PrivateKey::SetPrivatePart(const Integer& x)
+{
+    x_ = x;
+}
+
+
+DSA_Signer::DSA_Signer(const DSA_PrivateKey& key)
+    : key_(key)
+{}
+
+
+word32 DSA_Signer::Sign(const byte* sha_digest, byte* sig,
+                        RandomNumberGenerator& rng)
+{
+    const Integer& p = key_.GetModulus();
+    const Integer& q = key_.GetSubGroupOrder();
+    const Integer& g = key_.GetSubGroupGenerator();
+    const Integer& x = key_.GetPrivatePart();
+
+    Integer k(rng, 1, q - 1);
+
+    r_ =  a_exp_b_mod_c(g, k, p);
+    r_ %= q;
+
+    Integer H(sha_digest, SHA::DIGEST_SIZE);  // sha Hash(m)
+
+    Integer kInv = k.InverseMod(q);
+    s_ = (kInv * (H + x*r_)) % q;
+
+    assert(!!r_ && !!s_);
+
+    int rSz = r_.ByteCount();
+
+    if (rSz == 19) {
+        sig[0] = 0;
+        sig++;
+    }
+    
+    r_.Encode(sig,  rSz);
+
+    int sSz = s_.ByteCount();
+
+    if (sSz == 19) {
+        sig[rSz] = 0;
+        sig++;
+    }
+
+    s_.Encode(sig + rSz, sSz);
+
+    return 40;
+}
+
+
+DSA_Verifier::DSA_Verifier(const DSA_PublicKey& key)
+    : key_(key)
+{}
+
+
+bool DSA_Verifier::Verify(const byte* sha_digest, const byte* sig)
+{
+    const Integer& p = key_.GetModulus();
+    const Integer& q = key_.GetSubGroupOrder();
+    const Integer& g = key_.GetSubGroupGenerator();
+    const Integer& y = key_.GetPublicPart();
+
+    int sz = q.ByteCount();
+
+    r_.Decode(sig, sz);
+    s_.Decode(sig + sz, sz);
+
+    if (r_ >= q || r_ < 1 || s_ >= q || s_ < 1)
+        return false;
+
+    Integer H(sha_digest, SHA::DIGEST_SIZE);  // sha Hash(m)
+
+    Integer w = s_.InverseMod(q);
+    Integer u1 = (H  * w) % q;
+    Integer u2 = (r_ * w) % q;
+
+    // verify r == ((g^u1 * y^u2) mod p) mod q
+    ModularArithmetic ma(p);
+    Integer v = ma.CascadeExponentiate(g, u1, y, u2);
+    v %= q;
+
+    return r_ == v;
+}
+
+
+
+
+const Integer& DSA_Signer::GetR() const
+{
+    return r_;
+}
+
+
+const Integer& DSA_Signer::GetS() const
+{
+    return s_;
+}
+
+
+const Integer& DSA_Verifier::GetR() const
+{
+    return r_;
+}
+
+
+const Integer& DSA_Verifier::GetS() const
+{
+    return s_;
+}
+
+
+} // namespace