vendor: revendor

vendor/github.com/russellhaering/goxmldsig/etreeutils/namespace.go

@@ -0,0 +1,252 @@
+package etreeutils
+
+import (
+	"errors"
+
+	"fmt"
+
+	"sort"
+
+	"github.com/beevik/etree"
+)
+
+const (
+	defaultPrefix = ""
+	xmlnsPrefix   = "xmlns"
+	xmlPrefix     = "xml"
+
+	XMLNamespace   = "http://www.w3.org/XML/1998/namespace"
+	XMLNSNamespace = "http://www.w3.org/2000/xmlns/"
+)
+
+var (
+	DefaultNSContext = NSContext{
+		prefixes: map[string]string{
+			defaultPrefix: XMLNamespace,
+			xmlPrefix:     XMLNamespace,
+			xmlnsPrefix:   XMLNSNamespace,
+		},
+	}
+
+	EmptyNSContext = NSContext{}
+
+	ErrReservedNamespace       = errors.New("disallowed declaration of reserved namespace")
+	ErrInvalidDefaultNamespace = errors.New("invalid default namespace declaration")
+	ErrTraversalHalted         = errors.New("traversal halted")
+)
+
+type ErrUndeclaredNSPrefix struct {
+	Prefix string
+}
+
+func (e ErrUndeclaredNSPrefix) Error() string {
+	return fmt.Sprintf("undeclared namespace prefix: '%s'", e.Prefix)
+}
+
+type NSContext struct {
+	prefixes map[string]string
+}
+
+func (ctx NSContext) SubContext(el *etree.Element) (NSContext, error) {
+	// The subcontext should inherit existing declared prefixes
+	prefixes := make(map[string]string, len(ctx.prefixes)+4)
+	for k, v := range ctx.prefixes {
+		prefixes[k] = v
+	}
+
+	// Merge new namespace declarations on top of existing ones.
+	for _, attr := range el.Attr {
+		if attr.Space == xmlnsPrefix {
+			// This attribute is a namespace declaration of the form "xmlns:<prefix>"
+
+			// The 'xml' namespace may only be re-declared with the name 'http://www.w3.org/XML/1998/namespace'
+			if attr.Key == xmlPrefix && attr.Value != XMLNamespace {
+				return ctx, ErrReservedNamespace
+			}
+
+			// The 'xmlns' namespace may not be re-declared
+			if attr.Key == xmlnsPrefix {
+				return ctx, ErrReservedNamespace
+			}
+
+			prefixes[attr.Key] = attr.Value
+		} else if attr.Space == defaultPrefix && attr.Key == xmlnsPrefix {
+			// This attribute is a default namespace declaration
+
+			// The xmlns namespace value may not be declared as the default namespace
+			if attr.Value == XMLNSNamespace {
+				return ctx, ErrInvalidDefaultNamespace
+			}
+
+			prefixes[defaultPrefix] = attr.Value
+		}
+	}
+
+	return NSContext{prefixes: prefixes}, nil
+}
+
+// LookupPrefix attempts to find a declared namespace for the specified prefix. If the prefix
+// is an empty string this will be the default namespace for this context. If the prefix is
+// undeclared in this context an ErrUndeclaredNSPrefix will be returned.
+func (ctx NSContext) LookupPrefix(prefix string) (string, error) {
+	if namespace, ok := ctx.prefixes[prefix]; ok {
+		return namespace, nil
+	}
+
+	return "", ErrUndeclaredNSPrefix{
+		Prefix: prefix,
+	}
+}
+
+func nsTraverse(ctx NSContext, el *etree.Element, handle func(NSContext, *etree.Element) error) error {
+	ctx, err := ctx.SubContext(el)
+	if err != nil {
+		return err
+	}
+
+	err = handle(ctx, el)
+	if err != nil {
+		return err
+	}
+
+	// Recursively traverse child elements.
+	for _, child := range el.ChildElements() {
+		err := nsTraverse(ctx, child, handle)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func detachWithNamespaces(ctx NSContext, el *etree.Element) (*etree.Element, error) {
+	ctx, err := ctx.SubContext(el)
+	if err != nil {
+		return nil, err
+	}
+
+	el = el.Copy()
+
+	// Build a new attribute list
+	attrs := make([]etree.Attr, 0, len(el.Attr))
+
+	// First copy over anything that isn't a namespace declaration
+	for _, attr := range el.Attr {
+		if attr.Space == xmlnsPrefix {
+			continue
+		}
+
+		if attr.Space == defaultPrefix && attr.Key == xmlnsPrefix {
+			continue
+		}
+
+		attrs = append(attrs, attr)
+	}
+
+	// Append all in-context namespace declarations
+	for prefix, namespace := range ctx.prefixes {
+		// Skip the implicit "xml" and "xmlns" prefix declarations
+		if prefix == xmlnsPrefix || prefix == xmlPrefix {
+			continue
+		}
+
+		// Also skip declararing the default namespace as XMLNamespace
+		if prefix == defaultPrefix && namespace == XMLNamespace {
+			continue
+		}
+
+		if prefix != defaultPrefix {
+			attrs = append(attrs, etree.Attr{
+				Space: xmlnsPrefix,
+				Key:   prefix,
+				Value: namespace,
+			})
+		} else {
+			attrs = append(attrs, etree.Attr{
+				Key:   xmlnsPrefix,
+				Value: namespace,
+			})
+		}
+	}
+
+	sort.Sort(SortedAttrs(attrs))
+
+	el.Attr = attrs
+
+	return el, nil
+}
+
+// NSSelectOne conducts a depth-first search for an element with the specified namespace
+// and tag. If such an element is found, a new *etree.Element is returned which is a
+// copy of the found element, but with all in-context namespace declarations attached
+// to the element as attributes.
+func NSSelectOne(el *etree.Element, namespace, tag string) (*etree.Element, error) {
+	var found *etree.Element
+
+	err := nsTraverse(DefaultNSContext, el, func(ctx NSContext, el *etree.Element) error {
+		currentNS, err := ctx.LookupPrefix(el.Space)
+		if err != nil {
+			return err
+		}
+
+		// Base case, el is the sought after element.
+		if currentNS == namespace && el.Tag == tag {
+			found, err = detachWithNamespaces(ctx, el)
+			return ErrTraversalHalted
+		}
+
+		return nil
+	})
+
+	if err != nil && err != ErrTraversalHalted {
+		return nil, err
+	}
+
+	return found, nil
+}
+
+// NSFindIterate conducts a depth-first traversal searching for elements with the
+// specified tag in the specified namespace. For each such element, the passed
+// handler function is invoked. If the handler function returns an error
+// traversal is immediately halted. If the error returned by the handler is
+// ErrTraversalHalted then nil will be returned by NSFindIterate. If any other
+// error is returned by the handler, that error will be returned by NSFindIterate.
+func NSFindIterate(el *etree.Element, namespace, tag string, handle func(*etree.Element) error) error {
+	err := nsTraverse(DefaultNSContext, el, func(ctx NSContext, el *etree.Element) error {
+		currentNS, err := ctx.LookupPrefix(el.Space)
+		if err != nil {
+			return err
+		}
+
+		// Base case, el is the sought after element.
+		if currentNS == namespace && el.Tag == tag {
+			return handle(el)
+		}
+
+		return nil
+	})
+
+	if err != nil && err != ErrTraversalHalted {
+		return err
+	}
+
+	return nil
+}
+
+// NSFindOne conducts a depth-first search for the specified element. If such an element
+// is found a reference to it is returned.
+func NSFindOne(el *etree.Element, namespace, tag string) (*etree.Element, error) {
+	var found *etree.Element
+
+	err := NSFindIterate(el, namespace, tag, func(el *etree.Element) error {
+		found = el
+		return ErrTraversalHalted
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return found, nil
+}

vendor/github.com/russellhaering/goxmldsig/etreeutils/sort.go

@@ -0,0 +1,43 @@
+package etreeutils
+
+import "github.com/beevik/etree"
+
+type SortedAttrs []etree.Attr
+
+func (a SortedAttrs) Len() int {
+	return len(a)
+}
+
+func (a SortedAttrs) Swap(i, j int) {
+	a[i], a[j] = a[j], a[i]
+}
+
+func (a SortedAttrs) Less(i, j int) bool {
+	// As I understand it: any "xmlns" attribute should come first, followed by any
+	// any "xmlns:prefix" attributes, presumably ordered by prefix. Lastly any other
+	// attributes in lexicographical order.
+	if a[i].Space == defaultPrefix && a[i].Key == xmlnsPrefix {
+		return true
+	}
+
+	if a[j].Space == defaultPrefix && a[j].Key == xmlnsPrefix {
+		return false
+	}
+
+	if a[i].Space == xmlnsPrefix {
+		if a[j].Space == xmlnsPrefix {
+			return a[i].Key < a[j].Key
+		}
+		return true
+	}
+
+	if a[j].Space == xmlnsPrefix {
+		return false
+	}
+
+	if a[i].Space == a[j].Space {
+		return a[i].Key < a[j].Key
+	}
+
+	return a[i].Space < a[j].Space
+}