Break out timestamping from signing logic for people making their own…

… signed URL's.

signer.go

@@ -9,8 +9,6 @@ import (
 	"http"
 	"os"
 	"strings"
-	"strconv"
-	"time"
 )
 
 // A signer simply holds the access & secret access keys
@@ -82,12 +80,10 @@ func (self *Signer) SignRequestV2(req *http.Request, canon func(*http.Request) s
 	req.Form.Del("Signature")
 	req.Form.Del("Timestamp")
 	req.Form.Del("Expires")
-	if req.Form.Get("Timestamp") == "" && req.Form.Get("Expires") == "" {
-		if exp > 0 {
-			req.Form.Set("Expires", strconv.Itoa64(time.Seconds()+exp))
-		} else {
-			req.Form.Set("Expires", time.UTC().Format(ISO8601TimestampFormat))
-		}
+	if exp > 0 {
+      Expires(req, nil, exp)
+	} else {
+      Timestamp(req, nil)
 	}
 
 	var sig []byte
@@ -121,8 +117,7 @@ func (self *Signer) SignRequestV1(req *http.Request, canon func(*http.Request) s
 
 	req.Form.Set("AWSAccessKeyId", self.AccessKey)
 	req.Form.Del("Signature")
-	req.Form.Set("Expires", strconv.Itoa64(time.Seconds()+exp))
-
+  Expires(req, nil, exp)
 	var sig []byte
 	sig, err = self.SignEncoded(crypto.SHA1, canon(req), base64.StdEncoding)
 

timeformats.go

@@ -1,8 +1,36 @@
 package aws
+
+import (
+	"http"
+  "strconv"
+	"time"
+)
 /* 
   Copyright (c) 2010, Abneptis LLC.
   See COPYRIGHT and LICENSE for details.
 */
 
 var SQSTimestampFormat = "2006-01-02T15:04:05MST"
 var ISO8601TimestampFormat = "2006-01-02T15:04:05Z"
+
+// Adds a current timestamp to the request (deleting any present timestamp).
+//  - you may optionally pass in a custom function to create the timestamp value,
+// otherwise we default to time.UTC().
+
+func Timestamp(req *http.Request, t func() *time.Time) {
+	if t == nil {
+		req.Form.Set("Timestamp", time.UTC().Format(ISO8601TimestampFormat))
+	} else {
+		req.Form.Set("Timestamp", t().Format(ISO8601TimestampFormat))
+	}
+}
+
+// Adds an expiration message to the request (as opposed to a timestamp)
+// You may supply a custom time() function, else time.Seconds() is used.
+func Expires(req *http.Request, t func() *time.Time, from_now int64) {
+	if t == nil {
+		req.Form.Set("Expires", strconv.Itoa64(time.Seconds() + from_now))
+	} else {
+		req.Form.Set("Expires", strconv.Itoa64(t().Seconds()+from_now))
+	}
+}