Add support for SSE-S3 server side encryption with vault (#6192)

Add support for sse-s3 encryption with vault as KMS.

Also refactoring code to make use of headers and functions defined in
crypto package and clean up duplicated code.

vendor/github.com/hashicorp/hcl/parse.go

@@ -0,0 +1,39 @@
+package hcl
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/hcl/hcl/ast"
+	hclParser "github.com/hashicorp/hcl/hcl/parser"
+	jsonParser "github.com/hashicorp/hcl/json/parser"
+)
+
+// ParseBytes accepts as input byte slice and returns ast tree.
+//
+// Input can be either JSON or HCL
+func ParseBytes(in []byte) (*ast.File, error) {
+	return parse(in)
+}
+
+// ParseString accepts input as a string and returns ast tree.
+func ParseString(input string) (*ast.File, error) {
+	return parse([]byte(input))
+}
+
+func parse(in []byte) (*ast.File, error) {
+	switch lexMode(in) {
+	case lexModeHcl:
+		return hclParser.Parse(in)
+	case lexModeJson:
+		return jsonParser.Parse(in)
+	}
+
+	return nil, fmt.Errorf("unknown config format")
+}
+
+// Parse parses the given input and returns the root object.
+//
+// The input format can be either HCL or JSON.
+func Parse(input string) (*ast.File, error) {
+	return parse([]byte(input))
+}