1 files changed, 121 insertions, 0 deletions
diff --git a/lib/pubkey/rsa/rsa.cpp b/lib/pubkey/rsa/rsa.cpp
new file mode 100644
index 000000000..199ce6ad8
--- /dev/null
+++ b/lib/pubkey/rsa/rsa.cpp
@@ -0,0 +1,121 @@
+/*
+* RSA
+* (C) 1999-2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/rsa.h>
+#include <botan/parsing.h>
+#include <botan/numthry.h>
+#include <botan/keypair.h>
+#include <future>
+
+namespace Botan {
+
+/*
+* Create a RSA private key
+*/
+RSA_PrivateKey::RSA_PrivateKey(RandomNumberGenerator& rng,
+                               size_t bits, size_t exp)
+   {
+   if(bits < 1024)
+      throw Invalid_Argument(algo_name() + ": Can't make a key that is only " +
+                             std::to_string(bits) + " bits long");
+   if(exp < 3 || exp % 2 == 0)
+      throw Invalid_Argument(algo_name() + ": Invalid encryption exponent");
+
+   e = exp;
+
+   do
+      {
+      p = random_prime(rng, (bits + 1) / 2, e);
+      q = random_prime(rng, bits - p.bits(), e);
+      n = p * q;
+      } while(n.bits() != bits);
+
+   d = inverse_mod(e, lcm(p - 1, q - 1));
+   d1 = d % (p - 1);
+   d2 = d % (q - 1);
+   c = inverse_mod(q, p);
+
+   gen_check(rng);
+   }
+
+/*
+* Check Private RSA Parameters
+*/
+bool RSA_PrivateKey::check_key(RandomNumberGenerator& rng, bool strong) const
+   {
+   if(!IF_Scheme_PrivateKey::check_key(rng, strong))
+      return false;
+
+   if(!strong)
+      return true;
+
+   if((e * d) % lcm(p - 1, q - 1) != 1)
+      return false;
+
+   return KeyPair::signature_consistency_check(rng, *this, "EMSA4(SHA-1)");
+   }
+
+RSA_Private_Operation::RSA_Private_Operation(const RSA_PrivateKey& rsa,
+                                             RandomNumberGenerator& rng) :
+   n(rsa.get_n()),
+   q(rsa.get_q()),
+   c(rsa.get_c()),
+   powermod_e_n(rsa.get_e(), rsa.get_n()),
+   powermod_d1_p(rsa.get_d1(), rsa.get_p()),
+   powermod_d2_q(rsa.get_d2(), rsa.get_q()),
+   mod_p(rsa.get_p())
+   {
+   BigInt k(rng, n.bits() - 1);
+   blinder = Blinder(powermod_e_n(k), inverse_mod(k, n), n);
+   }
+
+BigInt RSA_Private_Operation::private_op(const BigInt& m) const
+   {
+   if(m >= n)
+      throw Invalid_Argument("RSA private op - input is too large");
+
+   auto future_j1 = std::async(std::launch::async, powermod_d1_p, m);
+   BigInt j2 = powermod_d2_q(m);
+   BigInt j1 = future_j1.get();
+
+   j1 = mod_p.reduce(sub_mul(j1, j2, c));
+
+   return mul_add(j1, q, j2);
+   }
+
+secure_vector<byte>
+RSA_Private_Operation::sign(const byte msg[], size_t msg_len,
+                            RandomNumberGenerator& rng)
+   {
+   rng.add_entropy(msg, msg_len);
+
+   /* We don't check signatures against powermod_e_n here because
+      PK_Signer checks verification consistency for all signature
+      algorithms.
+   */
+
+   const BigInt m(msg, msg_len);
+   const BigInt x = blinder.unblind(private_op(blinder.blind(m)));
+   return BigInt::encode_1363(x, n.bytes());
+   }
+
+/*
+* RSA Decryption Operation
+*/
+secure_vector<byte>
+RSA_Private_Operation::decrypt(const byte msg[], size_t msg_len)
+   {
+   const BigInt m(msg, msg_len);
+   const BigInt x = blinder.unblind(private_op(blinder.blind(m)));
+
+   BOTAN_ASSERT(m == powermod_e_n(x),
+                "RSA decrypt passed consistency check");
+
+   return BigInt::encode_locked(x);
+   }
+
+}