RSA Security 5 manual Int BDigestInit

B_DigestInit

B_DigestInit

B_DigestInit

int B_DigestInit (
B_ALGORITHM_OBJ	algorithmObject,	/* algorithm object */
B_KEY_OBJ	keyObject,	/* key object */
B_ALGORITHM_CHOOSER algorithmChooser,		/* algorithm chooser */
A_SURRENDER_CTX	*surrenderContext	/* surrender context */
);

Description

B_DigestInit initializes algorithmObject for computing a message digest using the algorithm specified by a previous call to B_SetAlgorithmInfo. The chooser for selecting the algorithm method is algorithmChooser. The key object for supplying the key information is keyObject; it should be (B_KEY_OBJ)NULL_PTR for keyless digesting algorithms. 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.

only needs to be called once to set up a digest algorithm. The B_DigestUpdate routine can be called multiple times to process blocks of data, and B_DigestFinal is called once to process the last block which includes producing the result. After B_DigestFinal is called, B_DigestUpdate can be called to start digesting another sequence of blocks. There is no need to call B_DigestInit again.

Return value

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

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