Let p1 and p2 be pointers to buffers formatted as described previously representing the first and second flows of the key negotiation. In the previous problem you assembled and hashed the concatenation of all of p1 followed by all of p2 up to and including X but excluding Auth_B. The data Auth_B purportedly contains Bobs RSA signature of this hash. Write a function int flow12_authb_verify(void *p1, void *p2) that returns 0 if the signature does not verify and non-zero if it does verify. To verify an RSA signature, you raise the signature to the public exponent (mod the modulus), which should evaluate to the thing that was signed. If the result is the same number as the hash, then the hash (and therefore the data) is verified. Bobs public key will be given in the C starter code in hex. You will have to call BN_hex2bn in order to convert it to a BIGNUM. To use BN_hex2bn you allocate a BIGNUM, which returns a pointer bn, and then you pass a pointer to this pointer: BN_hex2bn(&bn, hexstring). You will need to allocate and free your BIGNUMs in this problem. You will also need to allocate and free a BN_CTX.