From a031b83a09a8628435317a03f199cdc18b78262f Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Wed, 1 Nov 2017 11:24:59 -0400 Subject: Initial checkin from CRI-O repo Signed-off-by: Matthew Heon --- .../github.com/opencontainers/go-digest/digest.go | 154 +++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 vendor/github.com/opencontainers/go-digest/digest.go (limited to 'vendor/github.com/opencontainers/go-digest/digest.go') diff --git a/vendor/github.com/opencontainers/go-digest/digest.go b/vendor/github.com/opencontainers/go-digest/digest.go new file mode 100644 index 000000000..69e1d2b54 --- /dev/null +++ b/vendor/github.com/opencontainers/go-digest/digest.go @@ -0,0 +1,154 @@ +// Copyright 2017 Docker, Inc. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package digest + +import ( + "fmt" + "hash" + "io" + "regexp" + "strings" +) + +// 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. +type Digest string + +// NewDigest returns a Digest from alg and a hash.Hash object. +func NewDigest(alg Algorithm, h hash.Hash) Digest { + return NewDigestFromBytes(alg, h.Sum(nil)) +} + +// 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 NewDigestFromBytes(alg Algorithm, p []byte) Digest { + return Digest(fmt.Sprintf("%s:%x", alg, p)) +} + +// NewDigestFromHex returns a Digest from alg and a the hex encoded digest. +func NewDigestFromHex(alg, hex string) Digest { + return Digest(fmt.Sprintf("%s:%s", alg, hex)) +} + +// DigestRegexp matches valid digest types. +var DigestRegexp = regexp.MustCompile(`[a-zA-Z0-9-_+.]+:[a-fA-F0-9]+`) + +// DigestRegexpAnchored matches valid digest types, anchored to the start and end of the match. +var DigestRegexpAnchored = regexp.MustCompile(`^` + DigestRegexp.String() + `$`) + +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") +) + +// Parse parses s and returns the validated digest object. An error will +// be returned if the format is invalid. +func Parse(s string) (Digest, error) { + d := Digest(s) + return d, d.Validate() +} + +// FromReader consumes the content of rd until io.EOF, returning canonical digest. +func FromReader(rd io.Reader) (Digest, error) { + return Canonical.FromReader(rd) +} + +// FromBytes digests the input and returns a Digest. +func FromBytes(p []byte) Digest { + return Canonical.FromBytes(p) +} + +// FromString digests the input and returns a Digest. +func FromString(s string) Digest { + return Canonical.FromString(s) +} + +// Validate checks that the contents of d is a valid digest, returning an +// error if not. +func (d Digest) Validate() error { + s := string(d) + + i := strings.Index(s, ":") + + // validate i then run through regexp + if i < 0 || i+1 == len(s) || !DigestRegexpAnchored.MatchString(s) { + return ErrDigestInvalidFormat + } + + algorithm := Algorithm(s[:i]) + if !algorithm.Available() { + return ErrDigestUnsupported + } + + // Digests much always be hex-encoded, ensuring that their hex portion will + // always be size*2 + if algorithm.Size()*2 != len(s[i+1:]) { + return ErrDigestInvalidLength + } + + return nil +} + +// Algorithm returns the algorithm portion of the digest. This will panic if +// the underlying digest is not in a valid format. +func (d Digest) Algorithm() Algorithm { + return Algorithm(d[:d.sepIndex()]) +} + +// Verifier returns a writer object that can be used to verify a stream of +// content against the digest. If the digest is invalid, the method will panic. +func (d Digest) Verifier() Verifier { + return hashVerifier{ + hash: d.Algorithm().Hash(), + digest: d, + } +} + +// Hex returns the hex digest portion of the digest. This will panic if the +// underlying digest is not in a valid format. +func (d Digest) Hex() string { + return string(d[d.sepIndex()+1:]) +} + +func (d Digest) String() string { + return string(d) +} + +func (d Digest) sepIndex() int { + i := strings.Index(string(d), ":") + + if i < 0 { + panic(fmt.Sprintf("no ':' separator in digest %q", d)) + } + + return i +} -- cgit v1.2.3-54-g00ecf