Shamir's trick implementation.

[crypto_lab3.git] / src / RsaCrt.cpp

diff --git a/src/RsaCrt.cpp b/src/RsaCrt.cpp
index 0a9273e..869fce5 100644 (file)
--- a/src/RsaCrt.cpp
+++ b/src/RsaCrt.cpp
@@ -34,22 +34,23 @@ pair<Rsa::KeyPub, RsaCrt::KeyPriv> RsaCrt::generateRSAKeys(uint exponent, uint k
 
 mpz_class RsaCrt::sign(const mpz_class& m, const KeyPriv& kPriv)
 {
-   mpz_class sp, sq;
-
-   mpz_powm_sec(sp.get_mpz_t(), m.get_mpz_t(), kPriv.dp.get_mpz_t(), kPriv.p.get_mpz_t());
-   mpz_powm_sec(sq.get_mpz_t(), m.get_mpz_t(), kPriv.dq.get_mpz_t(), kPriv.q.get_mpz_t());
-
-   return sq + ((kPriv.qInv * (sp - sq)) % kPriv.p) * kPriv.q;
+   return sign(m, kPriv, false);
 }
 
 mpz_class RsaCrt::signWithFaultySp(const mpz_class& m, const KeyPriv& kPriv)
+{
+   return sign(m, kPriv, true);
+}
+
+mpz_class RsaCrt::sign(const mpz_class& m, const KeyPriv& kPriv, bool withError)
 {
    mpz_class sp, sq;
 
    mpz_powm_sec(sp.get_mpz_t(), m.get_mpz_t(), kPriv.dp.get_mpz_t(), kPriv.p.get_mpz_t());
    mpz_powm_sec(sq.get_mpz_t(), m.get_mpz_t(), kPriv.dq.get_mpz_t(), kPriv.q.get_mpz_t());
 
-   mpz_combit(sp.get_mpz_t(), 42); // Flip the fourty second bit.
+   if (withError)
+      mpz_combit(sp.get_mpz_t(), 42); // Flip the fourty second bit.
 
    return sq + ((kPriv.qInv * (sp - sq)) % kPriv.p) * kPriv.q;
 }