tpf_SHA512_Update: Update message digest value

Use this function to update the 64-byte message digest value that is built by using Secure Hashing Algorithm 512 (SHA-512).

Last updated

Added in 2019.

Format

#include  <tpf/tpfapi.h>
int tpf_SHA512_Update(struct tpf_SHA512_CTX *dctx,
                      void *tpf_data_in,
                      int tpf_data_len);
dctx
A pointer to the tpf_SHA512_CTX structure.
tpf_data_in
A pointer to the data to be hashed.
tpf_data_len
The length of the data to be hashed. Valid values for this parameter are 0 - 1000000.

Normal return

TPF_DIGEST_OK
The message digest was successfully updated.

Error return

If an error occurred, one of the following error codes is returned:
TPF_SHA_CTX_BAD
The pointer to the tpf_SHA512_CTX structure is not valid because the pointer is bad or does not point to a valid SHA-512 structure.
TPF_SHA_PTR_BAD
The pointer to the data to be hashed is not valid because the pointer is bad or the storage pointed to is not addressable.
TPF_SHA_LEN_BAD
The length of the data to be hashed is not valid.
TPF_SHA_HARDWARE_NOT_INSTALLED
The CP Assist for Cryptographic Function (CPACF) is not available on the processor or does not support the SHA-512 algorithm.
TPF_SHA_STATE_CHECK
The message digest computation was issued before cryptographic restart processing completed.

Programming considerations

  • The CPACF must be installed and support the SHA-512 algorithm on the processor that the function call is issued from.
  • Use the tpf_SHA512_Init, tpf_SHA512_Update, and tpf_SHA512_Final functions to create a message digest for discontiguous data.
  • If the data to be hashed exists in contiguous storage, use the tpf_SHA512_Digest function to create the message digest.
  • If this function is called from an assembly language program through the CALLC macro, include the ICPACF.MAC DSECT in the program to define the function return codes.

Examples

The following example creates a message digest from discontiguous data. 
#include  <tpf/tpfapi.h>
     {
          char plain_text1[];
          char plain_text2[];
          struct tpf_SHA512_CTX *dctx;
          int size, rc;
          char md[64]="";

          dctx = tpf_SHA512_Init();
          if (dctx == TPF_DIGEST_NOALLOC)
             exit(0);
          rc = tpf_SHA512_Update(dctx, plain_text1, size);
          rc = tpf_SHA512_Update(dctx, plain_text2, size);
          rc = tpf_SHA512_Final(md, dctx);
     }