restic/vendor/github.com/minio/minio-go/utils.go

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2017-07-23 12:24:45 +00:00
/*
* Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2015 Minio, 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
*
* http://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 minio
import (
"crypto/md5"
"crypto/sha256"
"encoding/xml"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"regexp"
"strings"
"time"
"github.com/minio/minio-go/pkg/s3utils"
)
// xmlDecoder provide decoded value in xml.
func xmlDecoder(body io.Reader, v interface{}) error {
d := xml.NewDecoder(body)
return d.Decode(v)
}
// sum256 calculate sha256 sum for an input byte array.
func sum256(data []byte) []byte {
hash := sha256.New()
hash.Write(data)
return hash.Sum(nil)
}
// sumMD5 calculate sumMD5 sum for an input byte array.
func sumMD5(data []byte) []byte {
hash := md5.New()
hash.Write(data)
return hash.Sum(nil)
}
// getEndpointURL - construct a new endpoint.
func getEndpointURL(endpoint string, secure bool) (*url.URL, error) {
if strings.Contains(endpoint, ":") {
host, _, err := net.SplitHostPort(endpoint)
if err != nil {
return nil, err
}
if !s3utils.IsValidIP(host) && !s3utils.IsValidDomain(host) {
msg := "Endpoint: " + endpoint + " does not follow ip address or domain name standards."
return nil, ErrInvalidArgument(msg)
}
} else {
if !s3utils.IsValidIP(endpoint) && !s3utils.IsValidDomain(endpoint) {
msg := "Endpoint: " + endpoint + " does not follow ip address or domain name standards."
return nil, ErrInvalidArgument(msg)
}
}
// If secure is false, use 'http' scheme.
scheme := "https"
if !secure {
scheme = "http"
}
// Construct a secured endpoint URL.
endpointURLStr := scheme + "://" + endpoint
endpointURL, err := url.Parse(endpointURLStr)
if err != nil {
return nil, err
}
// Validate incoming endpoint URL.
if err := isValidEndpointURL(*endpointURL); err != nil {
return nil, err
}
return endpointURL, nil
}
// closeResponse close non nil response with any response Body.
// convenient wrapper to drain any remaining data on response body.
//
// Subsequently this allows golang http RoundTripper
// to re-use the same connection for future requests.
func closeResponse(resp *http.Response) {
// Callers should close resp.Body when done reading from it.
// If resp.Body is not closed, the Client's underlying RoundTripper
// (typically Transport) may not be able to re-use a persistent TCP
// connection to the server for a subsequent "keep-alive" request.
if resp != nil && resp.Body != nil {
// Drain any remaining Body and then close the connection.
// Without this closing connection would disallow re-using
// the same connection for future uses.
// - http://stackoverflow.com/a/17961593/4465767
io.Copy(ioutil.Discard, resp.Body)
resp.Body.Close()
}
}
var emptySHA256 = sum256(nil)
// Sentinel URL is the default url value which is invalid.
var sentinelURL = url.URL{}
// Verify if input endpoint URL is valid.
func isValidEndpointURL(endpointURL url.URL) error {
if endpointURL == sentinelURL {
return ErrInvalidArgument("Endpoint url cannot be empty.")
}
if endpointURL.Path != "/" && endpointURL.Path != "" {
return ErrInvalidArgument("Endpoint url cannot have fully qualified paths.")
}
if strings.Contains(endpointURL.Host, ".s3.amazonaws.com") {
if !s3utils.IsAmazonEndpoint(endpointURL) {
return ErrInvalidArgument("Amazon S3 endpoint should be 's3.amazonaws.com'.")
}
}
if strings.Contains(endpointURL.Host, ".googleapis.com") {
if !s3utils.IsGoogleEndpoint(endpointURL) {
return ErrInvalidArgument("Google Cloud Storage endpoint should be 'storage.googleapis.com'.")
}
}
return nil
}
// Verify if input expires value is valid.
func isValidExpiry(expires time.Duration) error {
expireSeconds := int64(expires / time.Second)
if expireSeconds < 1 {
return ErrInvalidArgument("Expires cannot be lesser than 1 second.")
}
if expireSeconds > 604800 {
return ErrInvalidArgument("Expires cannot be greater than 7 days.")
}
return nil
}
// make a copy of http.Header
func cloneHeader(h http.Header) http.Header {
h2 := make(http.Header, len(h))
for k, vv := range h {
vv2 := make([]string, len(vv))
copy(vv2, vv)
h2[k] = vv2
}
return h2
}
// Filter relevant response headers from
// the HEAD, GET http response. The function takes
// a list of headers which are filtered out and
// returned as a new http header.
func filterHeader(header http.Header, filterKeys []string) (filteredHeader http.Header) {
filteredHeader = cloneHeader(header)
for _, key := range filterKeys {
filteredHeader.Del(key)
}
return filteredHeader
}
// regCred matches credential string in HTTP header
var regCred = regexp.MustCompile("Credential=([A-Z0-9]+)/")
// regCred matches signature string in HTTP header
var regSign = regexp.MustCompile("Signature=([[0-9a-f]+)")
// Redact out signature value from authorization string.
func redactSignature(origAuth string) string {
if !strings.HasPrefix(origAuth, signV4Algorithm) {
// Set a temporary redacted auth
return "AWS **REDACTED**:**REDACTED**"
}
/// Signature V4 authorization header.
// Strip out accessKeyID from:
// Credential=<access-key-id>/<date>/<aws-region>/<aws-service>/aws4_request
newAuth := regCred.ReplaceAllString(origAuth, "Credential=**REDACTED**/")
// Strip out 256-bit signature from: Signature=<256-bit signature>
return regSign.ReplaceAllString(newAuth, "Signature=**REDACTED**")
}
// Get default location returns the location based on the input
// URL `u`, if region override is provided then all location
// defaults to regionOverride.
//
// If no other cases match then the location is set to `us-east-1`
// as a last resort.
func getDefaultLocation(u url.URL, regionOverride string) (location string) {
if regionOverride != "" {
return regionOverride
}
if s3utils.IsAmazonChinaEndpoint(u) {
return "cn-north-1"
}
if s3utils.IsAmazonGovCloudEndpoint(u) {
return "us-gov-west-1"
}
// Default to location to 'us-east-1'.
return "us-east-1"
}