113 lines
2.5 KiB
Go
113 lines
2.5 KiB
Go
// Copyright 2015 CoreOS, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package omaha
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import (
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"crypto/sha1"
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"crypto/sha256"
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"encoding/base64"
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"errors"
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"io"
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"os"
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"path/filepath"
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)
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var (
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PackageHashMismatchError = errors.New("package hash is invalid")
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PackageSizeMismatchError = errors.New("package size is invalid")
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)
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// Package represents a single downloadable file. The Sha256 attribute
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// is not a standard part of the Omaha protocol which only uses Sha1.
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type Package struct {
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Name string `xml:"name,attr"`
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Sha1 string `xml:"hash,attr"`
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Sha256 string `xml:"sha256,attr,omitempty"`
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Size uint64 `xml:"size,attr"`
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Required bool `xml:"required,attr"`
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}
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func (p *Package) FromPath(name string) error {
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f, err := os.Open(name)
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if err != nil {
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return err
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}
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defer f.Close()
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err = p.FromReader(f)
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if err != nil {
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return err
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}
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p.Name = filepath.Base(name)
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return nil
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}
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func (p *Package) FromReader(r io.Reader) error {
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sha1b64, sha256b64, n, err := multihash(r)
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if err != nil {
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return err
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}
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p.Sha1 = sha1b64
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p.Sha256 = sha256b64
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p.Size = uint64(n)
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return nil
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}
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func (p *Package) Verify(dir string) error {
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f, err := os.Open(filepath.Join(dir, p.Name))
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if err != nil {
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return err
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}
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defer f.Close()
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return p.VerifyReader(f)
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}
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func (p *Package) VerifyReader(r io.Reader) error {
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sha1b64, sha256b64, n, err := multihash(r)
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if err != nil {
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return err
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}
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if p.Size != uint64(n) {
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return PackageSizeMismatchError
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}
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if p.Sha1 != sha1b64 {
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return PackageHashMismatchError
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}
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// Allow Sha256 to be empty since it is a protocol extension.
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if p.Sha256 != "" && p.Sha256 != sha256b64 {
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return PackageHashMismatchError
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}
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return nil
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}
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func multihash(r io.Reader) (sha1b64, sha256b64 string, n int64, err error) {
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h1 := sha1.New()
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h256 := sha256.New()
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if n, err = io.Copy(io.MultiWriter(h1, h256), r); err != nil {
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return
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}
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sha1b64 = base64.StdEncoding.EncodeToString(h1.Sum(nil))
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sha256b64 = base64.StdEncoding.EncodeToString(h256.Sum(nil))
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return
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}
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