README
¶
polyval
This module implements POLYVAL per RFC 8452.
The universal hash function POLYVAL is the byte-wise reverse of GHASH.
Installation
go get github.com/ericlagergren/polyval@latest
Performance
The x86-64 and ARMv8 assembly backends run at about 0.25 cycles per byte. The x86-64 implementation requires SSE2 and PCLMULQDQ instructions. The ARMv8 implementation requires NEON and PMULL.
The default Go implementation will be selected if the CPU does
not support either assembly implementation. (This implementation
can also be selected with the purego build tag.) It is much
slower at around 9 cycles per byte.
Security
Disclosure
This project uses full disclosure. If you find a security bug in an implementation, please e-mail me or create a GitHub issue.
Disclaimer
You should only use cryptography libraries that have been reviewed by cryptographers or cryptography engineers. While I am a cryptography engineer, I'm not your cryptography engineer, and I have not had this project reviewed by any other cryptographers.
Documentation
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Overview ¶
Package polyval implements POLYVAL per RFC 8452.
The universal hash function POLYVAL is the byte-wise reverse of GHASH.
Index ¶
- Constants
- func Sum(key, data []byte) [Size]byte
- type Polyval
- func (p *Polyval) BlockSize() int
- func (p *Polyval) Init(key []byte) error
- func (p *Polyval) MarshalBinary() ([]byte, error)
- func (p *Polyval) Reset()
- func (p *Polyval) Size() int
- func (p *Polyval) Sum(b []byte) []byte
- func (p *Polyval) UnmarshalBinary(data []byte) error
- func (p *Polyval) Update(blocks []byte)
Constants ¶
const (
// Size is the size in bytes of a POLYVAL checksum.
Size = 16
)
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Polyval ¶
type Polyval struct {
// contains filtered or unexported fields
}
Polyval is an implementation of POLYVAL.
It operates similar to the standard library's Hash interface, but only accepts full blocks. Callers should pad the input accordingly.
POLYVAL is similar to GHASH. It operates in GF(2^128) defined by the irreducible polynomial
x^128 + x^127 + x^126 + x^121 + 1.
The field has characteristic 2, so addition is performed with XOR. Multiplication is polynomial multiplication reduced modulo the polynomial.
For more information on POLYVAL, see [rfc8452].
func (*Polyval) Init ¶
Init initializes a Polyval.
The key must be exactly 16 bytes long and cannot be all zero.
func (*Polyval) MarshalBinary ¶
MarshalBinary implements BinaryMarshaler.
It does not return an error.
func (*Polyval) Sum ¶
Sum appends the current hash to b and returns the resulting slice.
It does not change the underlying hash state.
func (*Polyval) UnmarshalBinary ¶
Unmarshalbinary implements BinaryUnmarshaler.
data must be exactly 160 bytes.
Source Files
Directories