X-Git-Url: http://git.euphorik.ch/?a=blobdiff_plain;f=src%2FRsaCrt.cpp;h=b07801338575ecc550b40a00d8aab945deb5f084;hb=2745bc6570ac32789650336b8c84a52d1883c62a;hp=9e2c3c9d81ba89ac3ffbc7b6db883e9a7af5d20a;hpb=91989c2627abc2cdf511f17169e4f862dc55e838;p=crypto_lab3.git

diff --git a/src/RsaCrt.cpp b/src/RsaCrt.cpp
index 9e2c3c9..b078013 100644
--- a/src/RsaCrt.cpp
+++ b/src/RsaCrt.cpp
@@ -7,24 +7,26 @@ using namespace std;
 
 pair<Rsa::KeyPub, RsaCrt::KeyPriv> RsaCrt::generateRSAKeys(uint exponent, uint keySizeBits)
 {
-   mpz_class phi;
+   mpz_class phi, d;
    Rsa::KeyPub kPub;
    KeyPriv kPriv;
 
    do
    {
-      kPub.e = kPriv.e = exponent;
+      kPub.e = exponent;
       kPriv.p = Rand::randPrime(keySizeBits / 2);
       kPriv.q = Rand::randPrime(keySizeBits / 2);
 
-      kPriv.n = kPub.n = kPriv.p * kPriv.q;
+      kPub.n = kPriv.p * kPriv.q;
       phi = (kPriv.p - 1) * (kPriv.q - 1);
 
-   } while (mpz_invert(kPriv.d.get_mpz_t(), kPub.e.get_mpz_t(), phi.get_mpz_t()) == 0);
+   // d = e^-1 (mode phi).
+   } while (mpz_invert(d.get_mpz_t(), kPub.e.get_mpz_t(), phi.get_mpz_t()) == 0);
 
-   kPriv.dp = kPriv.d % (kPriv.p - 1);
-   kPriv.dq = kPriv.d % (kPriv.q - 1);
+   kPriv.dp = d % (kPriv.p - 1);
+   kPriv.dq = d % (kPriv.q - 1);
 
+   // qInv = q^-1 (mod p)
    mpz_invert(kPriv.qInv.get_mpz_t(), kPriv.q.get_mpz_t(), kPriv.p.get_mpz_t());
 
    return make_pair(kPub, kPriv);
@@ -39,3 +41,17 @@ mpz_class RsaCrt::sign(const mpz_class& m, const KeyPriv& kPriv)
 
    return sq + ((kPriv.qInv * (sp - sq)) % kPriv.p) * kPriv.q;
 }
+
+mpz_class RsaCrt::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;
+}
+
+