Trucking along with S3 signing

common.go

@@ -2,6 +2,7 @@ package awsauth
 
 import (
 	"crypto/hmac"
+	"crypto/sha1"
 	"crypto/sha256"
 	"fmt"
 	"io/ioutil"
@@ -15,12 +16,25 @@ import (
 func serviceAndRegion(host string) (string, string) {
 	var region, service string
 	parts := strings.Split(host, ".")
+
 	service = parts[0]
+
 	if len(parts) >= 4 {
-		region = parts[1]
+		if parts[1] == "s3" {
+			region = parts[0]
+			service = parts[1]
+		} else {
+			region = parts[1]
+		}
 	} else {
-		region = "us-east-1" // default. http://docs.aws.amazon.com/general/latest/gr/rande.html
+		if strings.HasPrefix(parts[0], "s3-") {
+			service = parts[0][:2]
+			region = parts[0][3:]
+		} else {
+			region = "us-east-1" // default. http://docs.aws.amazon.com/general/latest/gr/rande.html
+		}
 	}
+
 	return service, region
 }
 
@@ -51,6 +65,12 @@ func hmacSHA256(key []byte, content string) []byte {
 	return mac.Sum(nil)
 }
 
+func hmacSHA1(key []byte, content string) []byte {
+	mac := hmac.New(sha1.New, key)
+	mac.Write([]byte(content))
+	return mac.Sum(nil)
+}
+
 func hashSHA256(content string) string {
 	h := sha256.New()
 	h.Write([]byte(content))

common_test.go

@@ -14,6 +14,18 @@ func TestCommonFunctions(t *testing.T) {
 		s2, r2 := serviceAndRegion("iam.amazonaws.com")
 		So(s2, ShouldEqual, "iam")
 		So(r2, ShouldEqual, "us-east-1")
+
+		s3, r3 := serviceAndRegion("bucketname.s3.amazonaws.com")
+		So(s3, ShouldEqual, "s3")
+		So(r3, ShouldEqual, "bucketname")
+
+		s4, r4 := serviceAndRegion("s3.amazonaws.com")
+		So(s4, ShouldEqual, "s3")
+		So(r4, ShouldEqual, "us-east-1")
+
+		s5, r5 := serviceAndRegion("s3-us-west-1.amazonaws.com")
+		So(s5, ShouldEqual, "s3")
+		So(r5, ShouldEqual, "us-west-1")
 	})
 
 	Convey("SHA-256 hashes should be properly hex-encoded (base 16)", t, func() {
@@ -33,6 +45,13 @@ func TestCommonFunctions(t *testing.T) {
 
 			So(actual, ShouldResemble, expected)
 		})
+
+		Convey("HMAC-SHA1 should be properly computed", func() {
+			expected := []byte{164, 77, 252, 0, 87, 109, 207, 110, 163, 75, 228, 122, 83, 255, 233, 237, 125, 206, 85, 70}
+			actual := hmacSHA1(key, contents)
+
+			So(actual, ShouldResemble, expected)
+		})
 	})
 
 	Convey("Strings should be properly concatenated with a delimiter", t, func() {

s3.go

@@ -2,9 +2,73 @@ package awsauth
 
 import (
 	"fmt"
+	"net/http"
+	"sort"
+	"strings"
+	"time"
 )
 
 func signatureS3(stringToSign string) string {
 	fmt.Println("TODO")
 	return ""
 }
+
+func canonicalAmzHeadersS3(req *http.Request) string {
+	var headers []string
+
+	for header := range req.Header {
+		standardized := strings.ToLower(strings.TrimSpace(header))
+		if strings.HasPrefix(standardized, "x-amz") {
+			headers = append(headers, standardized)
+		}
+	}
+
+	sort.Strings(headers)
+
+	for i, header := range headers {
+		headers[i] = header + ":" + strings.Replace(req.Header.Get(header), "\n", " ", -1)
+	}
+
+	return strings.Join(headers, "\n") + "\n"
+}
+
+func canonicalResourceS3(req *http.Request) string {
+	res := ""
+
+	if isS3VirtualHostedStyle(req) {
+		_, bucketname := serviceAndRegion(req.Host)
+		res += "/" + bucketname
+	}
+
+	res += req.URL.Path
+
+	for _, subres := range strings.Split(subresourcesS3, ",") {
+		if strings.HasPrefix(req.URL.RawQuery, subres) {
+			res += "?" + subres
+		}
+	}
+
+	return res
+}
+
+func prepareRequestS3(req *http.Request) *http.Request {
+	// TODO: test
+	if req.URL.Path == "" {
+		req.URL.Path += "/"
+	}
+	return req
+}
+
+func isS3VirtualHostedStyle(req *http.Request) bool {
+	service, _ := serviceAndRegion(req.Host)
+	return service == "s3" && strings.Count(req.Host, ".") == 3
+}
+
+func timestampS3() string {
+	return now().Format(timeFormatS3)
+}
+
+const (
+	timeFormatS3   = time.RFC1123Z
+	subresourcesS3 = "acl,lifecycle,location,logging,notification,partNumber,policy,requestPayment,torrent,uploadId,uploads,versionId,versioning,versions,website"
+)

s3_test.go

@@ -1,14 +1,34 @@
 package awsauth
 
 import (
-	//. "github.com/smartystreets/goconvey/convey"
-	//"net/http"
-	//"net/url"
+	. "github.com/smartystreets/goconvey/convey"
+	"net/http"
 	"testing"
-	//"time"
 )
 
 func TestSignatureS3(t *testing.T) {
 	// http://docs.aws.amazon.com/AmazonS3/2006-03-01/dev/RESTAuthentication.html
 
+	Convey("Given a GET request to Amazon S3", t, func() {
+		req, _ := http.NewRequest("GET", "https://bucketname.s3.amazonaws.com/photos/puppy.jpg", nil)
+		req.Header.Set("X-Amz-Meta-Something", "more foobar")
+		req.Header.Set("X-Amz-Date", "foobar")
+		req.Header.Set("X-Foobar", "nanoo-nanoo")
+
+		Convey("The CanonicalizedAmzHeaders should be built properly", func() {
+			actual := canonicalAmzHeadersS3(req)
+			So(actual, ShouldEqual, expectedCanonAmzHeadersS3)
+		})
+
+		Convey("The CanonicalizedResource should be built properly", func() {
+			actual := canonicalResourceS3(req)
+			So(actual, ShouldEqual, expectedCanonResourceS3)
+		})
+	})
 }
+
+var (
+	testCredS3                = &Credentials{"AKIAIOSFODNN7EXAMPLE", "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY"}
+	expectedCanonAmzHeadersS3 = "x-amz-date:foobar\nx-amz-meta-something:more foobar\n"
+	expectedCanonResourceS3   = "/bucketname/photos/puppy.jpg"
+)

sign4.go

@@ -76,8 +76,7 @@ func buildAuthHeaderV4(signature string, meta *metadata) string {
 }
 
 func timestampV4() string {
-	t := now().Format(timeFormatV4)
-	return t
+	return now().Format(timeFormatV4)
 }
 
 func tsDateV4(timestamp string) string {