Vendor dependencies for azure backend

vendor/github.com/Azure/azure-sdk-for-go/storage/blobsasuri.go

@@ -0,0 +1,106 @@
+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)
+	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 := "https,http"
+	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" {
+		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")
+}