BN_bn2dec
buf = BN_bn2dec(num);
t = BN_bn2dec(b);
char *BN_bn2dec(const BIGNUM */*a*/);
p1 = BN_bn2dec(t1);
p2 = BN_bn2dec(t2);
p1 = BN_bn2dec(nbytes);
char *p = BN_bn2dec(n->number);
char *p = BN_bn2dec(n);