The Prediction of Serial Number in OpenSSL’s X.509 Certificate

Algorithm 1

The function of RAND_add. RAND_add(void b, int n, double entropy).

Input: n, b, where b is divided into 20-byte-length block bi

//entropy is 0 by default

//md is 20-byte states; s is 1023 bytes PRNG states

for i=1 to n do

 t=size()-1

 =SHA1

 s[p:p+t mod 1023]=s[p:p+t mod 1023] [0:t]

 p=p+t+1 mod 1023

end for

q=min(q+size(b), 1023)

return , s, p, q