go.mod: bump osbuild/images to 0.55

vendor/github.com/letsencrypt/boulder/strictyaml/yaml.go

@@ -0,0 +1,46 @@
+// Package strictyaml provides a strict YAML unmarshaller based on `go-yaml/yaml`
+package strictyaml
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Unmarshal takes a byte array and an interface passed by reference. The
+// d.Decode will read the next YAML-encoded value from its input and store it in
+// the value pointed to by yamlObj. Any config keys from the incoming YAML
+// document which do not correspond to expected keys in the config struct will
+// result in errors.
+//
+// TODO(https://github.com/go-yaml/yaml/issues/639): Replace this function with
+// yaml.Unmarshal once a more ergonomic way to set unmarshal options is added
+// upstream.
+func Unmarshal(b []byte, yamlObj interface{}) error {
+	r := bytes.NewReader(b)
+
+	d := yaml.NewDecoder(r)
+	d.KnownFields(true)
+
+	// d.Decode will mutate yamlObj
+	err := d.Decode(yamlObj)
+
+	if err != nil {
+		// io.EOF is returned when the YAML document is empty.
+		if errors.Is(err, io.EOF) {
+			return fmt.Errorf("unmarshalling YAML, bytes cannot be nil: %w", err)
+		}
+		return fmt.Errorf("unmarshalling YAML: %w", err)
+	}
+
+	// As bytes are read by the decoder, the length of the byte buffer should
+	// decrease. If it doesn't, there's a problem.
+	if r.Len() != 0 {
+		return fmt.Errorf("yaml object of size %d bytes had %d bytes of unexpected unconsumed trailers", r.Size(), r.Len())
+	}
+
+	return nil
+}