package crc32

Import Path
	hash/crc32 (on golang.org and go.dev)

Dependency Relation
	imports 6 packages, and imported by 3 packages

Involved Source Files Package crc32 implements the 32-bit cyclic redundancy check, or CRC-32, checksum. See https://en.wikipedia.org/wiki/Cyclic_redundancy_check for information. Polynomials are represented in LSB-first form also known as reversed representation. See https://en.wikipedia.org/wiki/Mathematics_of_cyclic_redundancy_checks#Reversed_representations_and_reciprocal_polynomials for information. crc32_amd64.go crc32_generic.go crc32_amd64.s
Code Examples package main import ( "fmt" "hash/crc32" ) func main() { // In this package, the CRC polynomial is represented in reversed notation, // or LSB-first representation. // // LSB-first representation is a hexadecimal number with n bits, in which the // most significant bit represents the coefficient of x⁰ and the least significant // bit represents the coefficient of xⁿ⁻¹ (the coefficient for xⁿ is implicit). // // For example, CRC32-Q, as defined by the following polynomial, // x³²+ x³¹+ x²⁴+ x²²+ x¹⁶+ x¹⁴+ x⁸+ x⁷+ x⁵+ x³+ x¹+ x⁰ // has the reversed notation 0b11010101100000101000001010000001, so the value // that should be passed to MakeTable is 0xD5828281. crc32q := crc32.MakeTable(0xD5828281) fmt.Printf("%08x\n", crc32.Checksum([]byte("Hello world"), crc32q)) }
Package-Level Type Names (only one)
/* sort by: | */
Table is a 256-word table representing the polynomial for efficient processing. func MakeTable(poly uint32) *Table func Checksum(data []byte, tab *Table) uint32 func New(tab *Table) hash.Hash32 func Update(crc uint32, tab *Table, p []byte) uint32 var IEEETable *Table
Package-Level Functions (total 6)
Checksum returns the CRC-32 checksum of data using the polynomial represented by the Table.
ChecksumIEEE returns the CRC-32 checksum of data using the IEEE polynomial.
MakeTable returns a Table constructed from the specified polynomial. The contents of this Table must not be modified.
New creates a new hash.Hash32 computing the CRC-32 checksum using the polynomial represented by the Table. Its Sum method will lay the value out in big-endian byte order. The returned Hash32 also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.
NewIEEE creates a new hash.Hash32 computing the CRC-32 checksum using the IEEE polynomial. Its Sum method will lay the value out in big-endian byte order. The returned Hash32 also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.
Update returns the result of adding the bytes in p to the crc.
Package-Level Variables (only one)
IEEETable is the table for the IEEE polynomial.
Package-Level Constants (total 4)
Castagnoli's polynomial, used in iSCSI. Has better error detection characteristics than IEEE. https://dx.doi.org/10.1109/26.231911
IEEE is by far and away the most common CRC-32 polynomial. Used by ethernet (IEEE 802.3), v.42, fddi, gzip, zip, png, ...
Koopman's polynomial. Also has better error detection characteristics than IEEE. https://dx.doi.org/10.1109/DSN.2002.1028931
The size of a CRC-32 checksum in bytes.