src/RsaCrtShamirsTrick.h

   1 #ifndef RSACRT_SHAMIRS_TRICK_H
   2 #define RSACRT_SHAMIRS_TRICK_H
   3
   4 #include <utility>
   5 #include <exception>
   6
   7 #include <gmpxx.h>
   8
   9 #include "Rsa.h"
  10
  11 class RsaCrtShamirsTrick
  12 {
  13 public:
  14    class UnableToSignWithShamirsTrick : public std::exception {};
  15
  16    struct KeyPriv {
  17       mpz_class p;
  18       mpz_class q;
  19       mpz_class d;
  20       mpz_class qInv;
  21    };
  22
  23    /**
  24     * Generate a pair of keys (public, private).
  25     */
  26    static std::pair<Rsa::KeyPub, KeyPriv> generateRSAKeys(uint exponent, uint keySizeBits);
  27
  28    /**
  29     * m must not be greater or equal than kPriv.n.
  30     * Use the Shamir's trick to test if a fault has been created during the computation of Sp and Sq.
  31     * If so it throws 'UnableToSignWithShamirsTrick'.
  32     * @param m the message to sign. No padding is used.
  33     */
  34    static mpz_class sign(const mpz_class& m, const KeyPriv& kPriv);
  35
  36    /**
  37     * Sp is altered by flipping its 42nd bit.
  38     * @param m the message to sign. No padding is used.
  39     */
  40    static mpz_class signWithFaultySp(const mpz_class& m, const KeyPriv& kPriv);
  41
  42 private:
  43    static mpz_class sign(const mpz_class& m, const KeyPriv& kPriv, bool withError);
  44 };
  45
  46 #endif