SHA2FINAL224, SHA2FINAL256, SHA2FINAL384, and SHA2FINAL512

Use a token initialized by the corresponding SHA2INIT function to complete a SHA-2 hash of a series of texts and return a CHAR string with that hash value.

t: A token returned by a previous invocation of SHA2INITx or SHA2UPDATEx.
p: A pointer that specifies the address of a buffer to be added to the hash.
n: An expression that specifies the length (in bytes) of that buffer. It must have a computational type and will be converted to type size_t.

The length returned is one eighth of the bit length in the function name, so, for example, SHA2FINAL256 returns a CHAR(32) value.

These functions generate code that executes the KIMD and KLMD assembler instructions.

Examples

The following example performs a 256-bit SHA-2 hash of a file that is read one line at a time into a CHARACTER variable c.

        dcl token     pointer;
        dcl encoded   char(32);
        token = sha2init256();
        on endfile(input);
        do loop;
          read file(input) into(c);
          if endfile(input) then leave;
          token = sha2update256(token, addrdata(c), length(c));
        end;
        encoded = sha2final256(token, sysnull(), 0);

In the example, all the SHA function calls are in the same block of code. This is not necessary: the calls can occur in a set of routines as long as they all use the same token created by the SHA2INIT call.