address comments

weed/s3api/auto_signature_v4_test.go

@@ -6,13 +6,10 @@ import (
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
-	"net/url"
 	"sort"
-	"strconv"
 	"strings"
 	"sync"
 	"testing"
@@ -210,6 +207,53 @@ func mustNewPresignedRequest(iam *IdentityAccessManagement, method string, urlSt
 	return req
 }
 
+// preSignV4 adds presigned URL parameters to the request
+func preSignV4(iam *IdentityAccessManagement, req *http.Request, accessKey, secretKey string, expires int64) error {
+	// Create credential scope
+	now := time.Now().UTC()
+	dateStr := now.Format(iso8601Format)
+
+	// Create credential header
+	scope := fmt.Sprintf("%s/%s/%s/%s", now.Format(yyyymmdd), "us-east-1", "s3", "aws4_request")
+	credential := fmt.Sprintf("%s/%s", accessKey, scope)
+
+	// Get the query parameters
+	query := req.URL.Query()
+	query.Set("X-Amz-Algorithm", signV4Algorithm)
+	query.Set("X-Amz-Credential", credential)
+	query.Set("X-Amz-Date", dateStr)
+	query.Set("X-Amz-Expires", fmt.Sprintf("%d", expires))
+	query.Set("X-Amz-SignedHeaders", "host")
+
+	// Set the query on the URL (without signature yet)
+	req.URL.RawQuery = query.Encode()
+
+	// Get the payload hash
+	hashedPayload := getContentSha256Cksum(req)
+
+	// Extract signed headers
+	extractedSignedHeaders := make(http.Header)
+	extractedSignedHeaders["host"] = []string{req.Host}
+
+	// Get canonical request
+	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, hashedPayload, req.URL.RawQuery, req.URL.Path, req.Method)
+
+	// Get string to sign
+	stringToSign := getStringToSign(canonicalRequest, now, scope)
+
+	// Get signing key
+	signingKey := getSigningKey(secretKey, now.Format(yyyymmdd), "us-east-1", "s3")
+
+	// Calculate signature
+	signature := getSignature(signingKey, stringToSign)
+
+	// Add signature to query
+	query.Set("X-Amz-Signature", signature)
+	req.URL.RawQuery = query.Encode()
+
+	return nil
+}
+
 // Returns new HTTP request object.
 func newTestRequest(method, urlStr string, contentLength int64, body io.ReadSeeker) (*http.Request, error) {
 	if method == "" {
@@ -459,47 +503,6 @@ func signRequestV4(req *http.Request, accessKey, secretKey string) error {
 	return nil
 }
 
-// preSignV4 presign the request, in accordance with
-// http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-query-string-auth.html.
-func preSignV4(iam *IdentityAccessManagement, req *http.Request, accessKeyID, secretAccessKey string, expires int64) error {
-	// Presign is not needed for anonymous credentials.
-	if accessKeyID == "" || secretAccessKey == "" {
-		return errors.New("Presign cannot be generated without access and secret keys")
-	}
-
-	region := "us-east-1"
-	date := time.Now().UTC()
-	scope := getScope(date, region)
-	credential := fmt.Sprintf("%s/%s", accessKeyID, scope)
-
-	// Set URL query.
-	query := req.URL.Query()
-	query.Set("X-Amz-Algorithm", signV4Algorithm)
-	query.Set("X-Amz-Date", date.Format(iso8601Format))
-	query.Set("X-Amz-Expires", strconv.FormatInt(expires, 10))
-	query.Set("X-Amz-SignedHeaders", "host")
-	query.Set("X-Amz-Credential", credential)
-	query.Set("X-Amz-Content-Sha256", unsignedPayload)
-
-	// "host" is the only header required to be signed for Presigned URLs.
-	extractedSignedHeaders := make(http.Header)
-	extractedSignedHeaders.Set("host", req.Host)
-
-	queryStr := strings.Replace(query.Encode(), "+", "%20", -1)
-	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, unsignedPayload, queryStr, req.URL.Path, req.Method)
-	stringToSign := getStringToSign(canonicalRequest, date, scope)
-	signingKey := getSigningKey(secretAccessKey, date.Format(yyyymmdd), region, "s3")
-	signature := getSignature(signingKey, stringToSign)
-
-	req.URL.RawQuery = query.Encode()
-
-	// Add signature header to RawQuery.
-	req.URL.RawQuery += "&X-Amz-Signature=" + url.QueryEscape(signature)
-
-	// Construct the final presigned URL.
-	return nil
-}
-
 // 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