github.com/google/go-safeweb@v0.0.0-20231219055052-64d8cfc90fbb/safehttp/plugins/csp/trustedtypes.go (about)

     1  // Copyright 2022 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //	https://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package csp
    16  
    17  import (
    18  	"strings"
    19  
    20  	"github.com/google/go-safeweb/safehttp"
    21  	"github.com/google/go-safeweb/safehttp/plugins/csp/internalunsafecsp"
    22  )
    23  
    24  // TrustedTypesPolicy policy can be used to create a new CSP which makes
    25  // dangerous web API functions secure by default.
    26  //
    27  // See https://web.dev/trusted-types for more info.
    28  type TrustedTypesPolicy struct {
    29  	// ReportURI controls the report-uri directive. If ReportUri is empty, no report-uri
    30  	// directive will be set.
    31  	ReportURI string
    32  }
    33  
    34  // Serialize serializes this policy for use in a Content-Security-Policy header
    35  // or in a Content-Security-Policy-Report-Only header. A nonce will be provided
    36  // to Serialize which can be used in 'nonce-{random-nonce}' values in directives.
    37  func (t TrustedTypesPolicy) Serialize(nonce string, _ safehttp.InterceptorConfig) string {
    38  	var b strings.Builder
    39  	b.WriteString("require-trusted-types-for 'script'")
    40  
    41  	if t.ReportURI != "" {
    42  		b.WriteString("; report-uri ")
    43  		b.WriteString(t.ReportURI)
    44  	}
    45  
    46  	return b.String()
    47  }
    48  
    49  // Match matches strict policies overrides.
    50  func (TrustedTypesPolicy) Match(cfg safehttp.InterceptorConfig) bool {
    51  	_, ok := cfg.(internalunsafecsp.DisableTrustedTypes)
    52  	return ok
    53  }
    54  
    55  // Overridden checks the override level.
    56  func (TrustedTypesPolicy) Overridden(cfg safehttp.InterceptorConfig) (disabled, reportOnly bool) {
    57  	disable := cfg.(internalunsafecsp.DisableTrustedTypes)
    58  	return disable.SkipReports, true
    59  }