5.1.8.1 SHA - SHA256 Digest

The SHA command utilizes the SHA256 Hash algorithm for computing the hash of a message. The primary input to the command is the actual message. The message is submitted to the device in blocks of 1 to 64 bytes. The following procedure is used when no context switching is required:
  1. Issue the SHA command in Start mode. No message is included.
  2. Issue the SHA command in Update mode with 1 to 64 bytes of the message.
  3. Repeat step 2 until the total number of bytes of the message have been submitted.
  4. Issue the SHA command in End mode to complete the SHA256 calculation.
Table 5-25. Input Parameters SHA Standard Mode

Opcode
(1 Byte)

Mode
(1 Byte)

Param2
(2 Bytes)

Data
(Varies by Mode)

Description
0x470x000x00 000 bytesStart mode
0x010x00 [ByteCount]1 to 64 bytesUpdate mode
0x020x00 [ByteCount]0 to 64 bytes

Finalize mode:  Digest placed in Output Buffer and TempKey

0x420x00 [ByteCount]Finalize mode: Digest placed in Output Buffer and Message Digest Buffer
0xC20x00 [ByteCount]Finalize mode: Digest placed in Output Buffer only
Table 5-26. Output Response SHA256 Standard
NameModeSizeDescription
Response0x00, 0x011 byte0x00 if successful, otherwise an error code is received
0x02, 0x42, 0xC2

1 byte
32 bytes

If error code
SHA256 Digest