github.com/blixtra/rkt@v0.8.1-0.20160204105720-ab0d1add1a43/rkt/image/filefetcher.go (about)

     1  // Copyright 2015 The rkt Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package image
    16  
    17  import (
    18  	"errors"
    19  	"fmt"
    20  	"os"
    21  	"path/filepath"
    22  
    23  	"github.com/coreos/rkt/pkg/keystore"
    24  	rktflag "github.com/coreos/rkt/rkt/flag"
    25  	"github.com/coreos/rkt/store"
    26  	"github.com/hashicorp/errwrap"
    27  )
    28  
    29  // fileFetcher is used to fetch files from a local filesystem
    30  type fileFetcher struct {
    31  	InsecureFlags *rktflag.SecFlags
    32  	S             *store.Store
    33  	Ks            *keystore.Keystore
    34  	Debug         bool
    35  }
    36  
    37  // GetHash opens a file, optionally verifies it against passed asc,
    38  // stores it in the store and returns the hash.
    39  func (f *fileFetcher) GetHash(aciPath string, a *asc) (string, error) {
    40  	ensureLogger(f.Debug)
    41  	absPath, err := filepath.Abs(aciPath)
    42  	if err != nil {
    43  		return "", errwrap.Wrap(fmt.Errorf("failed to get an absolute path for %q", aciPath), err)
    44  	}
    45  	aciPath = absPath
    46  
    47  	aciFile, err := f.getFile(aciPath, a)
    48  	if err != nil {
    49  		return "", err
    50  	}
    51  	defer aciFile.Close()
    52  
    53  	key, err := f.S.WriteACI(aciFile, false)
    54  	if err != nil {
    55  		return "", err
    56  	}
    57  
    58  	return key, nil
    59  }
    60  
    61  func (f *fileFetcher) getFile(aciPath string, a *asc) (*os.File, error) {
    62  	if f.InsecureFlags.SkipImageCheck() && f.Ks != nil {
    63  		log.Printf("warning: image signature verification has been disabled")
    64  	}
    65  	if f.InsecureFlags.SkipImageCheck() || f.Ks == nil {
    66  		aciFile, err := os.Open(aciPath)
    67  		if err != nil {
    68  			return nil, errwrap.Wrap(errors.New("error opening ACI file"), err)
    69  		}
    70  		return aciFile, nil
    71  	}
    72  	aciFile, err := f.getVerifiedFile(aciPath, a)
    73  	if err != nil {
    74  		return nil, err
    75  	}
    76  	return aciFile, nil
    77  }
    78  
    79  // fetch opens and verifies the ACI.
    80  func (f *fileFetcher) getVerifiedFile(aciPath string, a *asc) (*os.File, error) {
    81  	f.maybeOverrideAsc(aciPath, a)
    82  	ascFile, err := a.Get()
    83  	if err != nil {
    84  		return nil, errwrap.Wrap(errors.New("error opening signature file"), err)
    85  	}
    86  	defer func() { maybeClose(ascFile) }()
    87  
    88  	aciFile, err := os.Open(aciPath)
    89  	if err != nil {
    90  		return nil, errwrap.Wrap(errors.New("error opening ACI file"), err)
    91  	}
    92  	defer func() { maybeClose(aciFile) }()
    93  
    94  	validator, err := newValidator(aciFile)
    95  	if err != nil {
    96  		return nil, err
    97  	}
    98  
    99  	entity, err := validator.ValidateWithSignature(f.Ks, ascFile)
   100  	if err != nil {
   101  		return nil, errwrap.Wrap(fmt.Errorf("image %q verification failed", validator.GetImageName()), err)
   102  	}
   103  	printIdentities(entity)
   104  
   105  	retAciFile := aciFile
   106  	aciFile = nil
   107  	return retAciFile, nil
   108  }
   109  
   110  func (f *fileFetcher) maybeOverrideAsc(aciPath string, a *asc) {
   111  	if a.Fetcher != nil {
   112  		return
   113  	}
   114  	a.Location = ascPathFromImgPath(aciPath)
   115  	a.Fetcher = &localAscFetcher{}
   116  }