package poly1305

Import Path
	vendor/golang.org/x/crypto/internal/poly1305 (on go.dev)

Dependency Relation
	imports 3 packages, and imported by one package


Involved Source Files

	
		Package poly1305 implements Poly1305 one-time message authentication code as
		specified in https://cr.yp.to/mac/poly1305-20050329.pdf.
		
		Poly1305 is a fast, one-time authentication function. It is infeasible for an
		attacker to generate an authenticator for a message without the key. However, a
		key must only be used for a single message. Authenticating two different
		messages with the same key allows an attacker to forge authenticators for other
		messages with the same key.
		
		Poly1305 was originally coupled with AES in order to make Poly1305-AES. AES was
		used with a fixed key in order to generate one-time keys from an nonce.
		However, in this package AES isn't used and the one-time key is specified
		directly.

	    sum_amd64.go
	    sum_generic.go
	    sum_amd64.s


Package-Level Type Names (only one)


	/* sort by:  |  */
	
		MAC is an io.Writer computing an authentication tag
		of the data written to it.
		
		MAC cannot be used like common hash.Hash implementations,
		because using a poly1305 key twice breaks its security.
		Therefore writing data to a running MAC after calling
		Sum or Verify causes it to panic.

		
			
				Size returns the number of bytes Sum will return.

			
				Sum computes the authenticator of all data written to the
				message authentication code.

			
				Verify returns whether the authenticator of all data written to
				the message authentication code matches the expected value.

			
				Write adds more data to the running message authentication code.
				It never returns an error.
				
				It must not be called after the first call of Sum or Verify.

		
			*MAC : internal/bisect.Writer
			*MAC : io.Writer
		
			func New(key *[32]byte) *MAC




Package-Level Functions (total 3)


	
		New returns a new MAC computing an authentication
		tag of all data written to it with the given key.
		This allows writing the message progressively instead
		of passing it as a single slice. Common users should use
		the Sum function instead.
		
		The key must be unique for each message, as authenticating
		two different messages with the same key allows an attacker
		to forge messages at will.


	
		Sum generates an authenticator for msg using a one-time key and puts the
		16-byte result into out. Authenticating two different messages with the same
		key allows an attacker to forge messages at will.


	
		Verify returns true if mac is a valid authenticator for m with the given key.




Package-Level Constants (only one)


	
		TagSize is the size, in bytes, of a poly1305 authenticator.