github.com/letsencrypt/boulder@v0.20251208.0/va/utf8filter.go (about)

     1  package va
     2  
     3  import (
     4  	"strings"
     5  	"unicode/utf8"
     6  
     7  	"github.com/letsencrypt/boulder/probs"
     8  )
     9  
    10  // replaceInvalidUTF8 replaces all invalid UTF-8 encodings with
    11  // Unicode REPLACEMENT CHARACTER.
    12  func replaceInvalidUTF8(input []byte) string {
    13  	if utf8.Valid(input) {
    14  		return string(input)
    15  	}
    16  
    17  	var b strings.Builder
    18  
    19  	// Ranging over a string in Go produces runes. When the range keyword
    20  	// encounters an invalid UTF-8 encoding, it returns REPLACEMENT CHARACTER.
    21  	for _, v := range string(input) {
    22  		b.WriteRune(v)
    23  	}
    24  	return b.String()
    25  }
    26  
    27  // Call replaceInvalidUTF8 on all string fields of a ProblemDetails
    28  // and return the result.
    29  func filterProblemDetails(prob *probs.ProblemDetails) *probs.ProblemDetails {
    30  	if prob == nil {
    31  		return nil
    32  	}
    33  	return &probs.ProblemDetails{
    34  		Type:       probs.ProblemType(replaceInvalidUTF8([]byte(prob.Type))),
    35  		Detail:     replaceInvalidUTF8([]byte(prob.Detail)),
    36  		HTTPStatus: prob.HTTPStatus,
    37  	}
    38  }