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package storage
import (
"errors"
"fmt"
"net/url"
"strings"
"time"
)
// GetSASURIWithSignedIPAndProtocol creates an URL to the specified blob which contains the Shared
// Access Signature with specified permissions and expiration time. Also includes signedIPRange and allowed protocols.
// If old API version is used but no signedIP is passed (ie empty string) then this should still work.
// We only populate the signedIP when it non-empty.
//
// See https://msdn.microsoft.com/en-us/library/azure/ee395415.aspx
func (b *Blob) GetSASURIWithSignedIPAndProtocol(expiry time.Time, permissions string, signedIPRange string, HTTPSOnly bool) (string, error) {
var (
signedPermissions = permissions
blobURL = b.GetURL()
)
canonicalizedResource, err := b.Container.bsc.client.buildCanonicalizedResource(blobURL, b.Container.bsc.auth, true)
if err != nil {
return "", err
}
// "The canonicalizedresouce portion of the string is a canonical path to the signed resource.
// It must include the service name (blob, table, queue or file) for version 2015-02-21 or
// later, the storage account name, and the resource name, and must be URL-decoded.
// -- https://msdn.microsoft.com/en-us/library/azure/dn140255.aspx
// We need to replace + with %2b first to avoid being treated as a space (which is correct for query strings, but not the path component).
canonicalizedResource = strings.Replace(canonicalizedResource, "+", "%2b", -1)
canonicalizedResource, err = url.QueryUnescape(canonicalizedResource)
if err != nil {
return "", err
}
signedExpiry := expiry.UTC().Format(time.RFC3339)
//If blob name is missing, resource is a container
signedResource := "c"
if len(b.Name) > 0 {
signedResource = "b"
}
protocols := ""
if HTTPSOnly {
protocols = "https"
}
stringToSign, err := blobSASStringToSign(b.Container.bsc.client.apiVersion, canonicalizedResource, signedExpiry, signedPermissions, signedIPRange, protocols)
if err != nil {
return "", err
}
sig := b.Container.bsc.client.computeHmac256(stringToSign)
sasParams := url.Values{
"sv": {b.Container.bsc.client.apiVersion},
"se": {signedExpiry},
"sr": {signedResource},
"sp": {signedPermissions},
"sig": {sig},
}
if b.Container.bsc.client.apiVersion >= "2015-04-05" {
if protocols != "" {
sasParams.Add("spr", protocols)
}
if signedIPRange != "" {
sasParams.Add("sip", signedIPRange)
}
}
sasURL, err := url.Parse(blobURL)
if err != nil {
return "", err
}
sasURL.RawQuery = sasParams.Encode()
return sasURL.String(), nil
}
// GetSASURI creates an URL to the specified blob which contains the Shared
// Access Signature with specified permissions and expiration time.
//
// See https://msdn.microsoft.com/en-us/library/azure/ee395415.aspx
func (b *Blob) GetSASURI(expiry time.Time, permissions string) (string, error) {
return b.GetSASURIWithSignedIPAndProtocol(expiry, permissions, "", false)
}
func blobSASStringToSign(signedVersion, canonicalizedResource, signedExpiry, signedPermissions string, signedIP string, protocols string) (string, error) {
var signedStart, signedIdentifier, rscc, rscd, rsce, rscl, rsct string
if signedVersion >= "2015-02-21" {
canonicalizedResource = "/blob" + canonicalizedResource
}
// https://msdn.microsoft.com/en-us/library/azure/dn140255.aspx#Anchor_12
if signedVersion >= "2015-04-05" {
return fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s", signedPermissions, signedStart, signedExpiry, canonicalizedResource, signedIdentifier, signedIP, protocols, signedVersion, rscc, rscd, rsce, rscl, rsct), nil
}
// reference: http://msdn.microsoft.com/en-us/library/azure/dn140255.aspx
if signedVersion >= "2013-08-15" {
return fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s", signedPermissions, signedStart, signedExpiry, canonicalizedResource, signedIdentifier, signedVersion, rscc, rscd, rsce, rscl, rsct), nil
}
return "", errors.New("storage: not implemented SAS for versions earlier than 2013-08-15")
}