Struct botan::HashFunction

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pub struct HashFunction { /* private fields */ }

Expand description

A hash function object

Implementations§

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impl HashFunction

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pub fn new(name: &str) -> Result<HashFunction>

Create a new hash function

Errors

Will fail if the named hash is not known

Examples

assert!(botan::HashFunction::new("SHA-256").is_ok());
assert!(botan::HashFunction::new("Hash9000").is_err());

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pub fn algo_name(&self) -> Result<String>

Return the name of this algorithm which may or may not exactly match what was provided to new()

Examples

let hash = botan::HashFunction::new("SHA-384").unwrap();
assert_eq!(hash.algo_name().unwrap(), "SHA-384");

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pub fn output_length(&self) -> Result<usize>

Return the output length of the hash function, in bytes

Examples

let hash = botan::HashFunction::new("SHA-256").unwrap();
assert_eq!(hash.output_length().unwrap(), 32);

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pub fn block_size(&self) -> Result<usize>

Return the block length of the hash function, in bytes

Examples

let hash = botan::HashFunction::new("SHA-256").unwrap();
assert_eq!(hash.block_size().unwrap(), 64);

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pub fn update(&mut self, data: &[u8]) -> Result<()>

Add data to a hash computation, may be called many times

Examples

let mut hash = botan::HashFunction::new("SHA-256").unwrap();
hash.update(&[1,2,3]).unwrap();
hash.update(&[4,5,6]).unwrap();

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pub fn finish(&mut self) -> Result<Vec<u8>>

Finalize the computation, returning the hash of the message

Examples

let mut hash = botan::HashFunction::new("SHA-256").unwrap();
hash.update(&[1,2,3]).unwrap();
hash.update(&[4,5,6]).unwrap();
let digest = hash.finish().unwrap();

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pub fn clear(&mut self) -> Result<()>

Clear the internal state of the hash function. It acts as if it was newly created, and is ready to compute a new digest. Basically the same as calling final, but without returning a result.

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pub fn duplicate(&self) -> Result<HashFunction>

Copy hash object state to a new object, allowing prefixes of messages to be hashed. This function is also called by clone.

Errors

Should not fail but might due to unexpected error

Examples

let mut hash = botan::HashFunction::new("SHA-256").unwrap();
hash.update(&[1,2,3]);
let mut hash2 = hash.duplicate().unwrap();
hash2.update(&[4,5,6]);
let result1 = hash.finish().unwrap(); // hash of 1,2,3
let result2 = hash2.finish().unwrap(); // hash of 1,2,3,4,5,6