83Plus:BCALLs:8090

Synopsis

Official Name: MD5Update

Other Name: CalculateMD5

BCALL Address: 8090

Calculates the MD5 checksum

Inputs

• BC: The length of the data
• HL: The location of the data

Outputs

• 8269: (4 bytes) Holds the length in bits of the data hashed so far.
• 8292: (16 bytes) Will be changed to contain the new (incremental) MD5 hash of the data you gave it

Destroys

83Plus:RAM:8259: (16 bytes) Alternate registers (roughly equivalent to the AA, BB, CC, and DD registers specified in the MD5 standard.) 83Plus:RAM:83A5: (64 bytes) Buffer holding data to be hashed.

Comments

This B_CALL incrementally changes the md5 "registers" for the data you give it. But it does not add the size word that is required to generate official MD5 hashes, you have to do this yourself if you want official hashes.

Example

B_CALL InitializeMD5
ld bc,0040h
ld hl,SomeAddress
B_CALL CalculateMD5

Credits and Contributions

• FloppusMaximus: For testing that this B_CALL also work with lengths unequal to 64 bytes