Documentation
¶
Index ¶
- Constants
- Variables
- type Algorithm
- func (a Algorithm) Available() bool
- func (a Algorithm) FromBytes(p []byte) Digest
- func (a Algorithm) FromReader(rd io.Reader) (Digest, error)
- func (a Algorithm) Hash() hash.Hash
- func (a Algorithm) New() Digester
- func (a *Algorithm) Set(value string) error
- func (a Algorithm) Size() int
- func (a Algorithm) String() string
- type Digest
- type Digester
Constants ¶
const (
// DigestSha256EmptyTar is the canonical sha256 digest of empty data
DigestSha256EmptyTar = "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
)
Variables ¶
var ( // ErrDigestInvalidFormat returned when digest format invalid. ErrDigestInvalidFormat = fmt.Errorf("invalid checksum digest format") // ErrDigestInvalidLength returned when digest has invalid length. ErrDigestInvalidLength = fmt.Errorf("invalid checksum digest length") // ErrDigestUnsupported returned when the digest algorithm is unsupported. ErrDigestUnsupported = fmt.Errorf("unsupported digest algorithm") )
var DigestRegexp = regexp.MustCompile(`[a-zA-Z0-9-_+.]+:[a-fA-F0-9]+`)
DigestRegexp matches valid digest types.
var DigestRegexpAnchored = regexp.MustCompile(`^` + DigestRegexp.String() + `$`)
DigestRegexpAnchored matches valid digest types, anchored to the start and end of the match.
Functions ¶
This section is empty.
Types ¶
type Algorithm ¶
type Algorithm string
Algorithm identifies and implementation of a digester by an identifier. Note the that this defines both the hash algorithm used and the string encoding.
const ( SHA256 Algorithm = "sha256" // sha256 with hex encoding SHA384 Algorithm = "sha384" // sha384 with hex encoding SHA512 Algorithm = "sha512" // sha512 with hex encoding // Canonical is the primary digest algorithm used with the distribution // project. Other digests may be used but this one is the primary storage // digest. Canonical = SHA256 )
supported digest types
func (Algorithm) Available ¶
Available returns true if the digest type is available for use. If this returns false, New and Hash will return nil.
func (Algorithm) FromReader ¶
FromReader returns the digest of the reader using the algorithm.
func (Algorithm) Hash ¶
Hash returns a new hash as used by the algorithm. If not available, the method will panic. Check Algorithm.Available() before calling.
func (Algorithm) New ¶
New returns a new digester for the specified algorithm. If the algorithm does not have a digester implementation, nil will be returned. This can be checked by calling Available before calling New.
type Digest ¶
type Digest string
Digest allows simple protection of hex formatted digest strings, prefixed by their algorithm. Strings of type Digest have some guarantee of being in the correct format and it provides quick access to the components of a digest string.
The following is an example of the contents of Digest types:
sha256:7173b809ca12ec5dee4506cd86be934c4596dd234ee82c0662eac04a8c2c71dc
This allows to abstract the digest behind this type and work only in those terms.
func FromReader ¶
FromReader returns the most valid digest for the underlying content using the canonical digest algorithm.
func NewDigestFromBytes ¶
NewDigestFromBytes returns a new digest from the byte contents of p. Typically, this can come from hash.Hash.Sum(...) or xxx.SumXXX(...) functions. This is also useful for rebuilding digests from binary serializations.
func NewDigestFromHex ¶
NewDigestFromHex returns a Digest from alg and a the hex encoded digest.
func ParseDigest ¶
ParseDigest parses s and returns the validated digest object. An error will be returned if the format is invalid.
func (Digest) Algorithm ¶
Algorithm returns the algorithm portion of the digest. This will panic if the underlying digest is not in a valid format.
type Digester ¶
type Digester interface {
Hash() hash.Hash // provides direct access to underlying hash instance.
Digest() Digest
}
Digester calculates the digest of written data. Writes should go directly to the return value of Hash, while calling Digest will return the current value of the digest.
Source Files