Initial QSfera import

Server/vendor/github.com/crewjam/saml/xmlenc/xmlenc.go

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+// Package xmlenc is a partial implementation of the xmlenc standard
+// as described in https://www.w3.org/TR/2002/REC-xmlenc-core-20021210/Overview.html.
+// The purpose of this implementation is to support encrypted SAML assertions.
+package xmlenc
+
+import (
+	"crypto/rand"
+	"hash"
+
+	"github.com/beevik/etree"
+)
+
+// RandReader is a thunk that allows test to replace the source of randomness used by
+// this package. By default it is Reader from crypto/rand.
+var RandReader = rand.Reader
+
+// Encrypter is an interface that encrypts things. Given a plaintext it returns an
+// XML EncryptedData or EncryptedKey element. The required type of `key` varies
+// depending on the implementation.
+type Encrypter interface {
+	Encrypt(key interface{}, plaintext []byte, nonce []byte) (*etree.Element, error)
+}
+
+// Decrypter is an interface that decrypts things. The Decrypt() method returns the
+// plaintext version of the EncryptedData or EncryptedKey element passed.
+//
+// You probably don't have to use this interface directly, instead you may call
+// Decrypt() and it will examine the element to determine which Decrypter to use.
+type Decrypter interface {
+	Algorithm() string
+	Decrypt(key interface{}, ciphertextEl *etree.Element) ([]byte, error)
+}
+
+// DigestMethod represents a digest method such as SHA1, etc.
+type DigestMethod interface {
+	Algorithm() string
+	Hash() hash.Hash
+}
+
+var (
+	decrypters    = map[string]Decrypter{}
+	digestMethods = map[string]DigestMethod{}
+)
+
+// RegisterDecrypter registers the specified decrypter to that it can be
+// used with Decrypt().
+func RegisterDecrypter(d Decrypter) {
+	decrypters[d.Algorithm()] = d
+}
+
+// RegisterDigestMethod registers the specified digest method to that it can be
+// used with Decrypt().
+func RegisterDigestMethod(dm DigestMethod) {
+	digestMethods[dm.Algorithm()] = dm
+}
+
+// BlockCipher implements a cipher with a fixed size key like AES or 3DES.
+type BlockCipher interface {
+	Encrypter
+	Decrypter
+	KeySize() int
+}