Fix http auth header parsing (#34936)

Using `strings.EqualFold` is wrong in many cases.

modules/base/tool.go

@@ -8,13 +8,10 @@ import (
 	"crypto/sha1"
 	"crypto/sha256"
 	"crypto/subtle"
-	"encoding/base64"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"hash"
 	"strconv"
-	"strings"
 	"time"
 
 	"code.gitea.io/gitea/modules/setting"
@@ -36,19 +33,6 @@ func ShortSha(sha1 string) string {
 	return util.TruncateRunes(sha1, 10)
 }
 
-// BasicAuthDecode decode basic auth string
-func BasicAuthDecode(encoded string) (string, string, error) {
-	s, err := base64.StdEncoding.DecodeString(encoded)
-	if err != nil {
-		return "", "", err
-	}
-
-	if username, password, ok := strings.Cut(string(s), ":"); ok {
-		return username, password, nil
-	}
-	return "", "", errors.New("invalid basic authentication")
-}
-
 // VerifyTimeLimitCode verify time limit code
 func VerifyTimeLimitCode(now time.Time, data string, minutes int, code string) bool {
 	if len(code) <= 18 {

modules/base/tool_test.go

@@ -26,25 +26,6 @@ func TestShortSha(t *testing.T) {
 	assert.Equal(t, "veryverylo", ShortSha("veryverylong"))
 }
 
-func TestBasicAuthDecode(t *testing.T) {
-	_, _, err := BasicAuthDecode("?")
-	assert.Equal(t, "illegal base64 data at input byte 0", err.Error())
-
-	user, pass, err := BasicAuthDecode("Zm9vOmJhcg==")
-	assert.NoError(t, err)
-	assert.Equal(t, "foo", user)
-	assert.Equal(t, "bar", pass)
-
-	_, _, err = BasicAuthDecode("aW52YWxpZA==")
-	assert.Error(t, err)
-
-	_, _, err = BasicAuthDecode("invalid")
-	assert.Error(t, err)
-
-	_, _, err = BasicAuthDecode("YWxpY2U=") // "alice", no colon
-	assert.Error(t, err)
-}
-
 func TestVerifyTimeLimitCode(t *testing.T) {
 	defer test.MockVariableValue(&setting.InstallLock, true)()
 	initGeneralSecret := func(secret string) {