PutObject handler gets initial support for signature v4, working

pkg/server/api/signature.go

@@ -0,0 +1,85 @@
+/*
+ * Minimalist Object Storage, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package api
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"github.com/minio/minio/pkg/auth"
+	"github.com/minio/minio/pkg/donut"
+	"github.com/minio/minio/pkg/iodine"
+)
+
+const (
+	authHeaderPrefix = "AWS4-HMAC-SHA256"
+)
+
+// StripAccessKeyID - strip only access key id from auth header
+func StripAccessKeyID(ah string) (string, error) {
+	if ah == "" {
+		return "", errors.New("Missing auth header")
+	}
+	authFields := strings.Split(ah, ",")
+	if len(authFields) != 3 {
+		return "", errors.New("Missing fields in Auth header")
+	}
+	authPrefixFields := strings.Fields(authFields[0])
+	if len(authPrefixFields) != 2 {
+		return "", errors.New("Missing fields in Auth header")
+	}
+	if authPrefixFields[0] != authHeaderPrefix {
+		return "", errors.New("Missing fields is Auth header")
+	}
+	credentials := strings.Split(authPrefixFields[1], "=")
+	if len(credentials) != 2 {
+		return "", errors.New("Missing fields in Auth header")
+	}
+	if len(strings.Split(authFields[1], "=")) != 2 {
+		return "", errors.New("Missing fields in Auth header")
+	}
+	if len(strings.Split(authFields[2], "=")) != 2 {
+		return "", errors.New("Missing fields in Auth header")
+	}
+	accessKeyID := strings.Split(credentials[1], "/")[0]
+	if !auth.IsValidAccessKey(accessKeyID) {
+		return "", errors.New("Invalid access key")
+	}
+	return accessKeyID, nil
+}
+
+// InitSignatureV4 initializing signature verification
+func InitSignatureV4(req *http.Request) (*donut.Signature, error) {
+	// strip auth from authorization header
+	ah := req.Header.Get("Authorization")
+	accessKeyID, err := StripAccessKeyID(ah)
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	authConfig, err := auth.LoadConfig()
+	if _, ok := authConfig.Users[accessKeyID]; !ok {
+		return nil, errors.New("Access ID not found")
+	}
+	signature := &donut.Signature{
+		AccessKeyID:     authConfig.Users[accessKeyID].AccessKeyID,
+		SecretAccessKey: authConfig.Users[accessKeyID].SecretAccessKey,
+		AuthHeader:      ah,
+		Request:         req,
+	}
+	return signature, nil
+}