Move all modules into src/ directory

7 files changed, 681 insertions, 0 deletions

diff --git a/src/engine/gnump/eng_gmp.cpp b/src/engine/gnump/eng_gmp.cpp
new file mode 100644
index 000000000..a0e18e059
--- /dev/null
+++ b/src/engine/gnump/eng_gmp.cpp
@@ -0,0 +1,377 @@
+/*************************************************
+* GMP Engine Source File                         *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/eng_gmp.h>
+#include <botan/gmp_wrap.h>
+#include <gmp.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* GMP IF Operation                               *
+*************************************************/
+class GMP_IF_Op : public IF_Operation
+   {
+   public:
+      BigInt public_op(const BigInt&) const;
+      BigInt private_op(const BigInt&) const;
+
+      IF_Operation* clone() const { return new GMP_IF_Op(*this); }
+
+      GMP_IF_Op(const BigInt& e_bn, const BigInt& n_bn, const BigInt&,
+                const BigInt& p_bn, const BigInt& q_bn, const BigInt& d1_bn,
+                const BigInt& d2_bn, const BigInt& c_bn) :
+         e(e_bn), n(n_bn), p(p_bn), q(q_bn), d1(d1_bn), d2(d2_bn), c(c_bn) {}
+   private:
+      const GMP_MPZ e, n, p, q, d1, d2, c;
+   };
+
+/*************************************************
+* GMP IF Public Operation                        *
+*************************************************/
+BigInt GMP_IF_Op::public_op(const BigInt& i_bn) const
+   {
+   GMP_MPZ i(i_bn);
+   mpz_powm(i.value, i.value, e.value, n.value);
+   return i.to_bigint();
+   }
+
+/*************************************************
+* GMP IF Private Operation                       *
+*************************************************/
+BigInt GMP_IF_Op::private_op(const BigInt& i_bn) const
+   {
+   if(mpz_cmp_ui(p.value, 0) == 0)
+      throw Internal_Error("GMP_IF_Op::private_op: No private key");
+
+   GMP_MPZ j1, j2, h(i_bn);
+
+   mpz_powm(j1.value, h.value, d1.value, p.value);
+   mpz_powm(j2.value, h.value, d2.value, q.value);
+   mpz_sub(h.value, j1.value, j2.value);
+   mpz_mul(h.value, h.value, c.value);
+   mpz_mod(h.value, h.value, p.value);
+   mpz_mul(h.value, h.value, q.value);
+   mpz_add(h.value, h.value, j2.value);
+   return h.to_bigint();
+   }
+
+/*************************************************
+* GMP DSA Operation                              *
+*************************************************/
+class GMP_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 GMP_DSA_Op(*this); }
+
+      GMP_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 GMP_MPZ x, y, p, q, g;
+   };
+
+/*************************************************
+* GMP DSA Verify Operation                       *
+*************************************************/
+bool GMP_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;
+
+   GMP_MPZ r(sig, q_bytes);
+   GMP_MPZ s(sig + q_bytes, q_bytes);
+   GMP_MPZ i(msg, msg_len);
+
+   if(mpz_cmp_ui(r.value, 0) <= 0 || mpz_cmp(r.value, q.value) >= 0)
+      return false;
+   if(mpz_cmp_ui(s.value, 0) <= 0 || mpz_cmp(s.value, q.value) >= 0)
+      return false;
+
+   if(mpz_invert(s.value, s.value, q.value) == 0)
+      return false;
+
+   GMP_MPZ si;
+   mpz_mul(si.value, s.value, i.value);
+   mpz_mod(si.value, si.value, q.value);
+   mpz_powm(si.value, g.value, si.value, p.value);
+
+   GMP_MPZ sr;
+   mpz_mul(sr.value, s.value, r.value);
+   mpz_mod(sr.value, sr.value, q.value);
+   mpz_powm(sr.value, y.value, sr.value, p.value);
+
+   mpz_mul(si.value, si.value, sr.value);
+   mpz_mod(si.value, si.value, p.value);
+   mpz_mod(si.value, si.value, q.value);
+
+   if(mpz_cmp(si.value, r.value) == 0)
+      return true;
+   return false;
+   }
+
+/*************************************************
+* GMP DSA Sign Operation                         *
+*************************************************/
+SecureVector<byte> GMP_DSA_Op::sign(const byte in[], u32bit length,
+                                    const BigInt& k_bn) const
+   {
+   if(mpz_cmp_ui(x.value, 0) == 0)
+      throw Internal_Error("GMP_DSA_Op::sign: No private key");
+
+   GMP_MPZ i(in, length);
+   GMP_MPZ k(k_bn);
+
+   GMP_MPZ r;
+   mpz_powm(r.value, g.value, k.value, p.value);
+   mpz_mod(r.value, r.value, q.value);
+
+   mpz_invert(k.value, k.value, q.value);
+
+   GMP_MPZ s;
+   mpz_mul(s.value, x.value, r.value);
+   mpz_add(s.value, s.value, i.value);
+   mpz_mul(s.value, s.value, k.value);
+   mpz_mod(s.value, s.value, q.value);
+
+   if(mpz_cmp_ui(r.value, 0) == 0 || mpz_cmp_ui(s.value, 0) == 0)
+      throw Internal_Error("GMP_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;
+   }
+
+/*************************************************
+* 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;
+   }
+
+/*************************************************
+* GMP ElGamal Operation                          *
+*************************************************/
+class GMP_ELG_Op : public ELG_Operation
+   {
+   public:
+      SecureVector<byte> encrypt(const byte[], u32bit, const BigInt&) const;
+      BigInt decrypt(const BigInt&, const BigInt&) const;
+
+      ELG_Operation* clone() const { return new GMP_ELG_Op(*this); }
+
+      GMP_ELG_Op(const DL_Group& group, const BigInt& y1, const BigInt& x1) :
+         x(x1), y(y1), g(group.get_g()), p(group.get_p()) {}
+   private:
+      GMP_MPZ x, y, g, p;
+   };
+
+/*************************************************
+* GMP ElGamal Encrypt Operation                  *
+*************************************************/
+SecureVector<byte> GMP_ELG_Op::encrypt(const byte in[], u32bit length,
+                                       const BigInt& k_bn) const
+   {
+   GMP_MPZ i(in, length);
+
+   if(mpz_cmp(i.value, p.value) >= 0)
+      throw Invalid_Argument("GMP_ELG_Op: Input is too large");
+
+   GMP_MPZ a, b, k(k_bn);
+
+   mpz_powm(a.value, g.value, k.value, p.value);
+   mpz_powm(b.value, y.value, k.value, p.value);
+   mpz_mul(b.value, b.value, i.value);
+   mpz_mod(b.value, b.value, p.value);
+
+   const u32bit p_bytes = p.bytes();
+   SecureVector<byte> output(2*p_bytes);
+   a.encode(output, p_bytes);
+   b.encode(output + p_bytes, p_bytes);
+   return output;
+   }
+
+/*************************************************
+* GMP ElGamal Decrypt Operation                  *
+*************************************************/
+BigInt GMP_ELG_Op::decrypt(const BigInt& a_bn, const BigInt& b_bn) const
+   {
+   if(mpz_cmp_ui(x.value, 0) == 0)
+      throw Internal_Error("GMP_ELG_Op::decrypt: No private key");
+
+   GMP_MPZ a(a_bn), b(b_bn);
+
+   if(mpz_cmp(a.value, p.value) >= 0 || mpz_cmp(b.value, p.value) >= 0)
+      throw Invalid_Argument("GMP_ELG_Op: Invalid message");
+
+   mpz_powm(a.value, a.value, x.value, p.value);
+   mpz_invert(a.value, a.value, p.value);
+   mpz_mul(a.value, a.value, b.value);
+   mpz_mod(a.value, a.value, p.value);
+   return a.to_bigint();
+   }
+
+/*************************************************
+* GMP DH Operation                               *
+*************************************************/
+class GMP_DH_Op : public DH_Operation
+   {
+   public:
+      BigInt agree(const BigInt& i) const;
+      DH_Operation* clone() const { return new GMP_DH_Op(*this); }
+
+      GMP_DH_Op(const DL_Group& group, const BigInt& x_bn) :
+         x(x_bn), p(group.get_p()) {}
+   private:
+      GMP_MPZ x, p;
+   };
+
+/*************************************************
+* GMP DH Key Agreement Operation                 *
+*************************************************/
+BigInt GMP_DH_Op::agree(const BigInt& i_bn) const
+   {
+   GMP_MPZ i(i_bn);
+   mpz_powm(i.value, i.value, x.value, p.value);
+   return i.to_bigint();
+   }
+
+}
+
+/*************************************************
+* GMP_Engine Constructor                         *
+*************************************************/
+GMP_Engine::GMP_Engine()
+   {
+   set_memory_hooks();
+   }
+
+/*************************************************
+* Acquire an IF op                               *
+*************************************************/
+IF_Operation* GMP_Engine::if_op(const BigInt& e, const BigInt& n,
+                                const BigInt& d, const BigInt& p,
+                                const BigInt& q, const BigInt& d1,
+                                const BigInt& d2, const BigInt& c) const
+   {
+   return new GMP_IF_Op(e, n, d, p, q, d1, d2, c);
+   }
+
+/*************************************************
+* Acquire a DSA op                               *
+*************************************************/
+DSA_Operation* GMP_Engine::dsa_op(const DL_Group& group, const BigInt& y,
+                                  const BigInt& x) const
+   {
+   return new GMP_DSA_Op(group, y, x);
+   }
+
+/*************************************************
+* 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);
+   }
+
+/*************************************************
+* Acquire an ElGamal op                          *
+*************************************************/
+ELG_Operation* GMP_Engine::elg_op(const DL_Group& group, const BigInt& y,
+                                  const BigInt& x) const
+   {
+   return new GMP_ELG_Op(group, y, x);
+   }
+
+/*************************************************
+* Acquire a DH op                                *
+*************************************************/
+DH_Operation* GMP_Engine::dh_op(const DL_Group& group, const BigInt& x) const
+   {
+   return new GMP_DH_Op(group, x);
+   }
+
+}
diff --git a/src/engine/gnump/eng_gmp.h b/src/engine/gnump/eng_gmp.h
new file mode 100644
index 000000000..b8b2081fa
--- /dev/null
+++ b/src/engine/gnump/eng_gmp.h
@@ -0,0 +1,43 @@
+/*************************************************
+* GMP Engine Header File                         *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#ifndef BOTAN_ENGINE_GMP_H__
+#define BOTAN_ENGINE_GMP_H__
+
+#include <botan/engine.h>
+
+namespace Botan {
+
+/*************************************************
+* GMP Engine                                     *
+*************************************************/
+class GMP_Engine : public Engine
+   {
+   public:
+      IF_Operation* if_op(const BigInt&, const BigInt&, const BigInt&,
+                          const BigInt&, const BigInt&, const BigInt&,
+                          const BigInt&, const BigInt&) const;
+
+      DSA_Operation* dsa_op(const DL_Group&, const BigInt&,
+                            const BigInt&) const;
+
+      NR_Operation* nr_op(const DL_Group&, const BigInt&, const BigInt&) const;
+
+      ELG_Operation* elg_op(const DL_Group&, const BigInt&,
+                            const BigInt&) const;
+
+      DH_Operation* dh_op(const DL_Group&, const BigInt&) const;
+
+      Modular_Exponentiator* mod_exp(const BigInt&,
+                                     Power_Mod::Usage_Hints) const;
+
+      GMP_Engine();
+   private:
+      static void set_memory_hooks();
+   };
+
+}
+
+#endif
diff --git a/src/engine/gnump/gmp_mem.cpp b/src/engine/gnump/gmp_mem.cpp
new file mode 100644
index 000000000..ea8ef4d3b
--- /dev/null
+++ b/src/engine/gnump/gmp_mem.cpp
@@ -0,0 +1,60 @@
+/*************************************************
+* GNU MP Memory Handlers Source File             *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/eng_gmp.h>
+#include <cstring>
+#include <gmp.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Allocator used by GNU MP                       *
+*************************************************/
+Allocator* gmp_alloc = 0;
+
+/*************************************************
+* Allocation Function for GNU MP                 *
+*************************************************/
+void* gmp_malloc(size_t n)
+   {
+   return gmp_alloc->allocate(n);
+   }
+
+/*************************************************
+* Reallocation Function for GNU MP               *
+*************************************************/
+void* gmp_realloc(void* ptr, size_t old_n, size_t new_n)
+   {
+   void* new_buf = gmp_alloc->allocate(new_n);
+   std::memcpy(new_buf, ptr, std::min(old_n, new_n));
+   gmp_alloc->deallocate(ptr, old_n);
+   return new_buf;
+   }
+
+/*************************************************
+* Deallocation Function for GNU MP               *
+*************************************************/
+void gmp_free(void* ptr, size_t n)
+   {
+   gmp_alloc->deallocate(ptr, n);
+   }
+
+}
+
+/*************************************************
+* Set the GNU MP memory functions                *
+*************************************************/
+void GMP_Engine::set_memory_hooks()
+   {
+   if(gmp_alloc == 0)
+      {
+      gmp_alloc = Allocator::get(true);
+      mp_set_memory_functions(gmp_malloc, gmp_realloc, gmp_free);
+      }
+   }
+
+}
diff --git a/src/engine/gnump/gmp_powm.cpp b/src/engine/gnump/gmp_powm.cpp
new file mode 100644
index 000000000..a5e3d1c0d
--- /dev/null
+++ b/src/engine/gnump/gmp_powm.cpp
@@ -0,0 +1,51 @@
+/*************************************************
+* GMP Modular Exponentiation Source File         *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/eng_gmp.h>
+#include <botan/gmp_wrap.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* GMP Modular Exponentiator                      *
+*************************************************/
+class GMP_Modular_Exponentiator : public Modular_Exponentiator
+   {
+   public:
+      void set_base(const BigInt& b) { base = b; }
+      void set_exponent(const BigInt& e) { exp = e; }
+      BigInt execute() const;
+      Modular_Exponentiator* copy() const
+         { return new GMP_Modular_Exponentiator(*this); }
+
+      GMP_Modular_Exponentiator(const BigInt& n) : mod(n) {}
+   private:
+      GMP_MPZ base, exp, mod;
+   };
+
+/*************************************************
+* Compute the result                             *
+*************************************************/
+BigInt GMP_Modular_Exponentiator::execute() const
+   {
+   GMP_MPZ r;
+   mpz_powm(r.value, base.value, exp.value, mod.value);
+   return r.to_bigint();
+   }
+
+}
+
+/*************************************************
+* Return the GMP-based modular exponentiator     *
+*************************************************/
+Modular_Exponentiator* GMP_Engine::mod_exp(const BigInt& n,
+                                           Power_Mod::Usage_Hints) const
+   {
+   return new GMP_Modular_Exponentiator(n);
+   }
+
+}
diff --git a/src/engine/gnump/gmp_wrap.cpp b/src/engine/gnump/gmp_wrap.cpp
new file mode 100644
index 000000000..4c73c2562
--- /dev/null
+++ b/src/engine/gnump/gmp_wrap.cpp
@@ -0,0 +1,96 @@
+/*************************************************
+* GMP Wrapper Source File                        *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/gmp_wrap.h>
+
+#define GNU_MP_VERSION_CODE_FOR(a,b,c) ((a << 16) | (b << 8) | (c))
+
+#define GNU_MP_VERSION_CODE \
+   GNU_MP_VERSION_CODE_FOR(__GNU_MP_VERSION, __GNU_MP_VERSION_MINOR, \
+                           __GNU_MP_VERSION_PATCHLEVEL)
+
+#if GNU_MP_VERSION_CODE < GNU_MP_VERSION_CODE_FOR(4,1,0)
+  #error Your GNU MP install is too old, upgrade to 4.1 or later
+#endif
+
+namespace Botan {
+
+/*************************************************
+* GMP_MPZ Constructor                            *
+*************************************************/
+GMP_MPZ::GMP_MPZ(const BigInt& in)
+   {
+   mpz_init(value);
+   if(in != 0)
+      mpz_import(value, in.sig_words(), -1, sizeof(word), 0, 0, in.data());
+   }
+
+/*************************************************
+* GMP_MPZ Constructor                            *
+*************************************************/
+GMP_MPZ::GMP_MPZ(const byte in[], u32bit length)
+   {
+   mpz_init(value);
+   mpz_import(value, length, 1, 1, 0, 0, in);
+   }
+
+/*************************************************
+* GMP_MPZ Copy Constructor                       *
+*************************************************/
+GMP_MPZ::GMP_MPZ(const GMP_MPZ& other)
+   {
+   mpz_init_set(value, other.value);
+   }
+
+/*************************************************
+* GMP_MPZ Destructor                             *
+*************************************************/
+GMP_MPZ::~GMP_MPZ()
+   {
+   mpz_clear(value);
+   }
+
+/*************************************************
+* GMP_MPZ Assignment Operator                    *
+*************************************************/
+GMP_MPZ& GMP_MPZ::operator=(const GMP_MPZ& other)
+   {
+   mpz_set(value, other.value);
+   return (*this);
+   }
+
+/*************************************************
+* Export the mpz_t as a bytestring               *
+*************************************************/
+void GMP_MPZ::encode(byte out[], u32bit length) const
+   {
+   size_t dummy = 0;
+   mpz_export(out + (length - bytes()), &dummy, 1, 1, 0, 0, value);
+   }
+
+/*************************************************
+* Return the number of significant bytes         *
+*************************************************/
+u32bit GMP_MPZ::bytes() const
+   {
+   return ((mpz_sizeinbase(value, 2) + 7) / 8);
+   }
+
+/*************************************************
+* GMP to BigInt Conversions                      *
+*************************************************/
+BigInt GMP_MPZ::to_bigint() const
+   {
+   BigInt out(BigInt::Positive, (bytes() + sizeof(word) - 1) / sizeof(word));
+   size_t dummy = 0;
+   mpz_export(out.get_reg(), &dummy, -1, sizeof(word), 0, 0, value);
+
+   if(mpz_sgn(value) < 0)
+      out.flip_sign();
+
+   return out;
+   }
+
+}
diff --git a/src/engine/gnump/gmp_wrap.h b/src/engine/gnump/gmp_wrap.h
new file mode 100644
index 000000000..09a8590c4
--- /dev/null
+++ b/src/engine/gnump/gmp_wrap.h
@@ -0,0 +1,36 @@
+/*************************************************
+* GMP MPZ Wrapper Header File                    *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#ifndef BOTAN_GMP_MPZ_WRAP_H__
+#define BOTAN_GMP_MPZ_WRAP_H__
+
+#include <botan/bigint.h>
+#include <gmp.h>
+
+namespace Botan {
+
+/*************************************************
+* Lightweight GMP mpz_t Wrapper                  *
+*************************************************/
+class GMP_MPZ
+   {
+   public:
+      mpz_t value;
+
+      BigInt to_bigint() const;
+      void encode(byte[], u32bit) const;
+      u32bit bytes() const;
+
+      GMP_MPZ& operator=(const GMP_MPZ&);
+
+      GMP_MPZ(const GMP_MPZ&);
+      GMP_MPZ(const BigInt& = 0);
+      GMP_MPZ(const byte[], u32bit);
+      ~GMP_MPZ();
+   };
+
+}
+
+#endif
diff --git a/src/engine/gnump/modinfo.txt b/src/engine/gnump/modinfo.txt
new file mode 100644
index 000000000..e65e411fd
--- /dev/null
+++ b/src/engine/gnump/modinfo.txt
@@ -0,0 +1,18 @@
+realname "GMP Engine"
+
+define ENGINE_GNU_MP
+
+load_on request
+
+<add>
+eng_gmp.cpp
+gmp_wrap.cpp
+gmp_mem.cpp
+gmp_powm.cpp
+eng_gmp.h
+gmp_wrap.h
+</add>
+
+<libs>
+all -> gmp
+</libs>