添加 github.com/pion/dtls 代码

dtls-2.0.9/pkg/crypto/signaturehash/errors.go

@@ -0,0 +1,9 @@
+package signaturehash
+
+import "errors"
+
+var (
+	errNoAvailableSignatureSchemes = errors.New("connection can not be created, no SignatureScheme satisfy this Config")
+	errInvalidSignatureAlgorithm   = errors.New("invalid signature algorithm")
+	errInvalidHashAlgorithm        = errors.New("invalid hash algorithm")
+)