signV4: Move pkg/signature to pkg/s3/signature4

Cleanup and move this to relevant path.

pkg/s3/signature4/v4-errors.go

@@ -0,0 +1,57 @@
+/*
+ * Minio Cloud Storage, (C) 2015, 2016 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 signature4
+
+import (
+	"fmt"
+
+	"github.com/minio/minio/pkg/probe"
+)
+
+type errFunc func(msg string, a ...string) *probe.Error
+
+// generic error factory which wraps around probe.NewError()
+func errFactory() errFunc {
+	return func(msg string, a ...string) *probe.Error {
+		return probe.NewError(fmt.Errorf("%s, Args: %s", msg, a)).Untrace()
+	}
+}
+
+// Various signature v4 errors.
+var (
+	ErrPolicyAlreadyExpired  = errFactory()
+	ErrInvalidRegion         = errFactory()
+	ErrInvalidDateFormat     = errFactory()
+	ErrInvalidService        = errFactory()
+	ErrInvalidRequestVersion = errFactory()
+	ErrMissingFields         = errFactory()
+	ErrMissingCredTag        = errFactory()
+	ErrCredMalformed         = errFactory()
+	ErrMissingSignTag        = errFactory()
+	ErrMissingSignHeadersTag = errFactory()
+	ErrMissingDateHeader     = errFactory()
+	ErrMalformedDate         = errFactory()
+	ErrMalformedExpires      = errFactory()
+	ErrAuthHeaderEmpty       = errFactory()
+	ErrUnsuppSignAlgo        = errFactory()
+	ErrMissingExpiresQuery   = errFactory()
+	ErrExpiredPresignRequest = errFactory()
+	ErrSignDoesNotMath       = errFactory()
+	ErrInvalidAccessKeyID    = errFactory()
+	ErrInvalidSecretKey      = errFactory()
+	ErrRegionISEmpty         = errFactory()
+)