java - Can SHA-1 algorithm be computed on a stream? With low memory footprint?

Question

I am looking for a way to compute SHA-1 checksums of very large files without having to fully load them into memory at once.

I don't know the details of the SHA-1 implementation and therefore would like to know if it is even possible to do that.

If you know the SAX XML parser, then what I look for would be something similar: Computing the SHA-1 checksum by only always loading a small part into memory at a time.

All the examples I found, at least in Java, always depend on fully loading the file/byte array/string into memory.

If you even know implementations (any language), then please let me know!

Answer 1

The Java docs say to use a MessageDigest class to compute SHA-1 on any arbitrary size data.