RSA Security 5 manual Int BKeyAgreePhase2

		B_KeyAgreePhase2
B_KeyAgreePhase2
int B_KeyAgreePhase2 (
B_ALGORITHM_OBJ algorithmObject,		/* algorithm object */
unsigned char	*output,	/* output data buffer */
unsigned int	*outputLen,	/* length of output data */
unsigned int	maxOutputLen,	/* size of output data buffer */
unsigned char	*input,	/* input data */
unsigned int	inputLen,	/* length of input data */
A_SURRENDER_CTX *surrenderContext		/* surrender context */
);

Description

B_KeyAgreePhase2 performs a round of key agreement as specified by algorithmObject, receiving inputLen bytes from input, which is the other party’s intermediate value. B_KeyAgreePhase2 writes the output to output, which is a buffer supplied by the caller of at least maxOutputLen bytes, and sets outputLen to the number of bytes written to output. If input is the other party’s final intermediate value, output is the agreed-upon key; otherwise, output is a new intermediate value to send to the other party. The surrender context for processing and canceling during lengthy operations is surrenderContext; if its value is (A_SURRENDER_CTX *)NULL_PTR, Crypto- C does not use it.

B_KeyAgreePhase2 may be called one or more times to process intermediate values, depending on how many other parties are involved in the key agreement. For an algorithm like Diffie-Hellman, B_KeyAgreePhase2 is called once.

Return value

Value	Description
0	Operation was successful.
non-zero	see Appendix A, ”Crypto-C Error Types”

C h a p t e r 4 D e t a i l s o f C r y p t o - C F u n c t i o n s 327