Upgrade dependent version: github.com/open-policy-agent/opa (#5315)

Upgrade dependent version: github.com/open-policy-agent/opa v0.18.0 -> v0.45.0

Signed-off-by: hongzhouzi <hongzhouzi@kubesphere.io>

Signed-off-by: hongzhouzi <hongzhouzi@kubesphere.io>

vendor/github.com/open-policy-agent/opa/bundle/hash.go

@@ -0,0 +1,141 @@
+// Copyright 2020 The OPA Authors.  All rights reserved.
+// Use of this source code is governed by an Apache2
+// license that can be found in the LICENSE file.
+
+package bundle
+
+import (
+	"bytes"
+	"crypto/md5"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/json"
+	"fmt"
+	"hash"
+	"io"
+	"sort"
+	"strings"
+)
+
+// HashingAlgorithm represents a subset of hashing algorithms implemented in Go
+type HashingAlgorithm string
+
+// Supported values for HashingAlgorithm
+const (
+	MD5       HashingAlgorithm = "MD5"
+	SHA1      HashingAlgorithm = "SHA-1"
+	SHA224    HashingAlgorithm = "SHA-224"
+	SHA256    HashingAlgorithm = "SHA-256"
+	SHA384    HashingAlgorithm = "SHA-384"
+	SHA512    HashingAlgorithm = "SHA-512"
+	SHA512224 HashingAlgorithm = "SHA-512-224"
+	SHA512256 HashingAlgorithm = "SHA-512-256"
+)
+
+// String returns the string representation of a HashingAlgorithm
+func (alg HashingAlgorithm) String() string {
+	return string(alg)
+}
+
+// SignatureHasher computes a signature digest for a file with (structured or unstructured) data and policy
+type SignatureHasher interface {
+	HashFile(v interface{}) ([]byte, error)
+}
+
+type hasher struct {
+	h func() hash.Hash // hash function factory
+}
+
+// NewSignatureHasher returns a signature hasher suitable for a particular hashing algorithm
+func NewSignatureHasher(alg HashingAlgorithm) (SignatureHasher, error) {
+	h := &hasher{}
+
+	switch alg {
+	case MD5:
+		h.h = md5.New
+	case SHA1:
+		h.h = sha1.New
+	case SHA224:
+		h.h = sha256.New224
+	case SHA256:
+		h.h = sha256.New
+	case SHA384:
+		h.h = sha512.New384
+	case SHA512:
+		h.h = sha512.New
+	case SHA512224:
+		h.h = sha512.New512_224
+	case SHA512256:
+		h.h = sha512.New512_256
+	default:
+		return nil, fmt.Errorf("unsupported hashing algorithm: %s", alg)
+	}
+
+	return h, nil
+}
+
+// HashFile hashes the file content, JSON or binary, both in golang native format.
+func (h *hasher) HashFile(v interface{}) ([]byte, error) {
+	hf := h.h()
+	walk(v, hf)
+	return hf.Sum(nil), nil
+}
+
+// walk hashes the file content, JSON or binary, both in golang native format.
+//
+// Computation for unstructured documents is a hash of the document.
+//
+// Computation for the types of structured JSON document is as follows:
+//
+// object: Hash {, then each key (in alphabetical order) and digest of the value, then comma (between items) and finally }.
+//
+// array: Hash [, then digest of the value, then comma (between items) and finally ].
+func walk(v interface{}, h io.Writer) {
+
+	switch x := v.(type) {
+	case map[string]interface{}:
+		_, _ = h.Write([]byte("{"))
+
+		var keys []string
+		for k := range x {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+
+		for i, key := range keys {
+			if i > 0 {
+				_, _ = h.Write([]byte(","))
+			}
+
+			_, _ = h.Write(encodePrimitive(key))
+			_, _ = h.Write([]byte(":"))
+			walk(x[key], h)
+		}
+
+		_, _ = h.Write([]byte("}"))
+	case []interface{}:
+		_, _ = h.Write([]byte("["))
+
+		for i, e := range x {
+			if i > 0 {
+				_, _ = h.Write([]byte(","))
+			}
+			walk(e, h)
+		}
+
+		_, _ = h.Write([]byte("]"))
+	case []byte:
+		_, _ = h.Write(x)
+	default:
+		_, _ = h.Write(encodePrimitive(x))
+	}
+}
+
+func encodePrimitive(v interface{}) []byte {
+	var buf bytes.Buffer
+	encoder := json.NewEncoder(&buf)
+	encoder.SetEscapeHTML(false)
+	_ = encoder.Encode(v)
+	return []byte(strings.Trim(buf.String(), "\n"))
+}