Shamir's trick implementation.

[crypto_lab3.git] / src / RsaCrtShamirsTrick.cpp

diff --git a/src/RsaCrtShamirsTrick.cpp b/src/RsaCrtShamirsTrick.cpp
index 0e01e4b..dffb20f 100644 (file)
--- a/src/RsaCrtShamirsTrick.cpp
+++ b/src/RsaCrtShamirsTrick.cpp
@@ -30,6 +30,16 @@ pair<Rsa::KeyPub, RsaCrtShamirsTrick::KeyPriv> RsaCrtShamirsTrick::generateRSAKe
 }
 
 mpz_class RsaCrtShamirsTrick::sign(const mpz_class& m, const KeyPriv& kPriv)
+{
+   return sign(m, kPriv, false);
+}
+
+mpz_class RsaCrtShamirsTrick::signWithFaultySp(const mpz_class& m, const KeyPriv& kPriv)
+{
+   return sign(m, kPriv, true);
+}
+
+mpz_class RsaCrtShamirsTrick::sign(const mpz_class& m, const KeyPriv& kPriv, bool withError)
 {
    const mpz_class r = Rand::randPrime(64);
 
@@ -40,8 +50,11 @@ mpz_class RsaCrtShamirsTrick::sign(const mpz_class& m, const KeyPriv& kPriv)
    const mpz_class sqExponent = kPriv.d % ((kPriv.q - 1) * (r - 1)); // d mod phi(q * r).
 
    mpz_class spr, sqr;
-   mpz_powm(spr.get_mpz_t(), m.get_mpz_t(), spExponent.get_mpz_t(), pr.get_mpz_t());
-   mpz_powm(sqr.get_mpz_t(), m.get_mpz_t(), sqExponent.get_mpz_t(), qr.get_mpz_t());
+   mpz_powm(spr.get_mpz_t(), m.get_mpz_t(), spExponent.get_mpz_t(), pr.get_mpz_t()); // spr = m^exp mod p*r.
+   mpz_powm(sqr.get_mpz_t(), m.get_mpz_t(), sqExponent.get_mpz_t(), qr.get_mpz_t()); // sqr = m^exp mod q*r.
+
+   if (withError)
+      mpz_combit(spr.get_mpz_t(), 42); // Flip the fourty second bit.
 
    if (spr % r != sqr % r)
       throw UnableToSignWithShamirsTrick();
@@ -51,16 +64,3 @@ mpz_class RsaCrtShamirsTrick::sign(const mpz_class& m, const KeyPriv& kPriv)
 
    return sq + ((kPriv.qInv * (sp - sq)) % kPriv.p) * kPriv.q;
 }
-
-mpz_class RsaCrtShamirsTrick::signWithFaultySp(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());
-
-   mpz_combit(sp.get_mpz_t(), 42); // Flip the fourty second bit.
-
-   return sq + ((kPriv.qInv * (sp - sq)) % kPriv.p) * kPriv.q;*/
-   return sp;
-}