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restic/vendor/github.com/minio/minio-go/pkg/s3utils/utils.go
2017-09-13 14:09:48 +02:00

277 lines
8.8 KiB
Go

/*
* Minio Go Library for Amazon S3 Compatible Cloud Storage (C) 2016 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 s3utils
import (
"bytes"
"encoding/hex"
"errors"
"net"
"net/url"
"regexp"
"sort"
"strings"
"unicode/utf8"
)
// Sentinel URL is the default url value which is invalid.
var sentinelURL = url.URL{}
// IsValidDomain validates if input string is a valid domain name.
func IsValidDomain(host string) bool {
// See RFC 1035, RFC 3696.
host = strings.TrimSpace(host)
if len(host) == 0 || len(host) > 255 {
return false
}
// host cannot start or end with "-"
if host[len(host)-1:] == "-" || host[:1] == "-" {
return false
}
// host cannot start or end with "_"
if host[len(host)-1:] == "_" || host[:1] == "_" {
return false
}
// host cannot start or end with a "."
if host[len(host)-1:] == "." || host[:1] == "." {
return false
}
// All non alphanumeric characters are invalid.
if strings.ContainsAny(host, "`~!@#$%^&*()+={}[]|\\\"';:><?/") {
return false
}
// No need to regexp match, since the list is non-exhaustive.
// We let it valid and fail later.
return true
}
// IsValidIP parses input string for ip address validity.
func IsValidIP(ip string) bool {
return net.ParseIP(ip) != nil
}
// IsVirtualHostSupported - verifies if bucketName can be part of
// virtual host. Currently only Amazon S3 and Google Cloud Storage
// would support this.
func IsVirtualHostSupported(endpointURL url.URL, bucketName string) bool {
if endpointURL == sentinelURL {
return false
}
// bucketName can be valid but '.' in the hostname will fail SSL
// certificate validation. So do not use host-style for such buckets.
if endpointURL.Scheme == "https" && strings.Contains(bucketName, ".") {
return false
}
// Return true for all other cases
return IsAmazonEndpoint(endpointURL) || IsGoogleEndpoint(endpointURL)
}
// AmazonS3Host - regular expression used to determine if an arg is s3 host.
var AmazonS3Host = regexp.MustCompile("^s3[.-]?(.*?)\\.amazonaws\\.com$")
// IsAmazonEndpoint - Match if it is exactly Amazon S3 endpoint.
func IsAmazonEndpoint(endpointURL url.URL) bool {
if IsAmazonChinaEndpoint(endpointURL) {
return true
}
if IsAmazonGovCloudEndpoint(endpointURL) {
return true
}
return AmazonS3Host.MatchString(endpointURL.Host)
}
// IsAmazonGovCloudEndpoint - Match if it is exactly Amazon S3 GovCloud endpoint.
func IsAmazonGovCloudEndpoint(endpointURL url.URL) bool {
if endpointURL == sentinelURL {
return false
}
return (endpointURL.Host == "s3-us-gov-west-1.amazonaws.com" ||
IsAmazonFIPSGovCloudEndpoint(endpointURL))
}
// IsAmazonFIPSGovCloudEndpoint - Match if it is exactly Amazon S3 FIPS GovCloud endpoint.
func IsAmazonFIPSGovCloudEndpoint(endpointURL url.URL) bool {
if endpointURL == sentinelURL {
return false
}
return endpointURL.Host == "s3-fips-us-gov-west-1.amazonaws.com"
}
// IsAmazonChinaEndpoint - Match if it is exactly Amazon S3 China endpoint.
// Customers who wish to use the new Beijing Region are required
// to sign up for a separate set of account credentials unique to
// the China (Beijing) Region. Customers with existing AWS credentials
// will not be able to access resources in the new Region, and vice versa.
// For more info https://aws.amazon.com/about-aws/whats-new/2013/12/18/announcing-the-aws-china-beijing-region/
func IsAmazonChinaEndpoint(endpointURL url.URL) bool {
if endpointURL == sentinelURL {
return false
}
return endpointURL.Host == "s3.cn-north-1.amazonaws.com.cn"
}
// IsGoogleEndpoint - Match if it is exactly Google cloud storage endpoint.
func IsGoogleEndpoint(endpointURL url.URL) bool {
if endpointURL == sentinelURL {
return false
}
return endpointURL.Host == "storage.googleapis.com"
}
// Expects ascii encoded strings - from output of urlEncodePath
func percentEncodeSlash(s string) string {
return strings.Replace(s, "/", "%2F", -1)
}
// QueryEncode - encodes query values in their URL encoded form. In
// addition to the percent encoding performed by urlEncodePath() used
// here, it also percent encodes '/' (forward slash)
func QueryEncode(v url.Values) string {
if v == nil {
return ""
}
var buf bytes.Buffer
keys := make([]string, 0, len(v))
for k := range v {
keys = append(keys, k)
}
sort.Strings(keys)
for _, k := range keys {
vs := v[k]
prefix := percentEncodeSlash(EncodePath(k)) + "="
for _, v := range vs {
if buf.Len() > 0 {
buf.WriteByte('&')
}
buf.WriteString(prefix)
buf.WriteString(percentEncodeSlash(EncodePath(v)))
}
}
return buf.String()
}
// if object matches reserved string, no need to encode them
var reservedObjectNames = regexp.MustCompile("^[a-zA-Z0-9-_.~/]+$")
// EncodePath encode the strings from UTF-8 byte representations to HTML hex escape sequences
//
// This is necessary since regular url.Parse() and url.Encode() functions do not support UTF-8
// non english characters cannot be parsed due to the nature in which url.Encode() is written
//
// This function on the other hand is a direct replacement for url.Encode() technique to support
// pretty much every UTF-8 character.
func EncodePath(pathName string) string {
if reservedObjectNames.MatchString(pathName) {
return pathName
}
var encodedPathname string
for _, s := range pathName {
if 'A' <= s && s <= 'Z' || 'a' <= s && s <= 'z' || '0' <= s && s <= '9' { // §2.3 Unreserved characters (mark)
encodedPathname = encodedPathname + string(s)
continue
}
switch s {
case '-', '_', '.', '~', '/': // §2.3 Unreserved characters (mark)
encodedPathname = encodedPathname + string(s)
continue
default:
len := utf8.RuneLen(s)
if len < 0 {
// if utf8 cannot convert return the same string as is
return pathName
}
u := make([]byte, len)
utf8.EncodeRune(u, s)
for _, r := range u {
hex := hex.EncodeToString([]byte{r})
encodedPathname = encodedPathname + "%" + strings.ToUpper(hex)
}
}
}
return encodedPathname
}
// We support '.' with bucket names but we fallback to using path
// style requests instead for such buckets.
var (
validBucketName = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9\.\-\_\:]{1,61}[A-Za-z0-9]$`)
validBucketNameStrict = regexp.MustCompile(`^[a-z0-9][a-z0-9\.\-]{1,61}[a-z0-9]$`)
ipAddress = regexp.MustCompile(`^(\d+\.){3}\d+$`)
)
// Common checker for both stricter and basic validation.
func checkBucketNameCommon(bucketName string, strict bool) (err error) {
if strings.TrimSpace(bucketName) == "" {
return errors.New("Bucket name cannot be empty")
}
if len(bucketName) < 3 {
return errors.New("Bucket name cannot be smaller than 3 characters")
}
if len(bucketName) > 63 {
return errors.New("Bucket name cannot be greater than 63 characters")
}
if ipAddress.MatchString(bucketName) {
return errors.New("Bucket name cannot be an ip address")
}
if strings.Contains(bucketName, "..") {
return errors.New("Bucket name contains invalid characters")
}
if strict {
if !validBucketNameStrict.MatchString(bucketName) {
err = errors.New("Bucket name contains invalid characters")
}
return err
}
if !validBucketName.MatchString(bucketName) {
err = errors.New("Bucket name contains invalid characters")
}
return err
}
// CheckValidBucketName - checks if we have a valid input bucket name.
func CheckValidBucketName(bucketName string) (err error) {
return checkBucketNameCommon(bucketName, false)
}
// CheckValidBucketNameStrict - checks if we have a valid input bucket name.
// This is a stricter version.
// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingBucket.html
func CheckValidBucketNameStrict(bucketName string) (err error) {
return checkBucketNameCommon(bucketName, true)
}
// CheckValidObjectNamePrefix - checks if we have a valid input object name prefix.
// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
func CheckValidObjectNamePrefix(objectName string) error {
if len(objectName) > 1024 {
return errors.New("Object name cannot be greater than 1024 characters")
}
if !utf8.ValidString(objectName) {
return errors.New("Object name with non UTF-8 strings are not supported")
}
return nil
}
// CheckValidObjectName - checks if we have a valid input object name.
// - http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingMetadata.html
func CheckValidObjectName(objectName string) error {
if strings.TrimSpace(objectName) == "" {
return errors.New("Object name cannot be empty")
}
return CheckValidObjectNamePrefix(objectName)
}