func validateEmail(ctx context.Context, address string, resolver bdns.DNSResolver) (prob *probs.ProblemDetails) { emails, err := mail.ParseAddressList(address) if err != nil { return probs.InvalidEmail(unparseableEmailDetail) } if len(emails) > 1 { return probs.InvalidEmail(multipleAddressDetail) } splitEmail := strings.SplitN(emails[0].Address, "@", -1) domain := strings.ToLower(splitEmail[len(splitEmail)-1]) var resultMX []string var resultA []net.IP var errMX, errA error var wg sync.WaitGroup wg.Add(2) go func() { resultMX, errMX = resolver.LookupMX(ctx, domain) wg.Done() }() go func() { resultA, errA = resolver.LookupHost(ctx, domain) wg.Done() }() wg.Wait() // We treat timeouts as non-failures for best-effort email validation // See: https://github.com/letsencrypt/boulder/issues/2260 if problemIsTimeout(errMX) || problemIsTimeout(errA) { return nil } if errMX != nil { prob := bdns.ProblemDetailsFromDNSError(errMX) prob.Type = probs.InvalidEmailProblem return prob } else if len(resultMX) > 0 { return nil } if errA != nil { prob := bdns.ProblemDetailsFromDNSError(errA) prob.Type = probs.InvalidEmailProblem return prob } else if len(resultA) > 0 { return nil } return probs.InvalidEmail(emptyDNSResponseDetail) }
func validateEmail(ctx context.Context, address string, resolver bdns.DNSResolver) (prob *probs.ProblemDetails) { emails, err := mail.ParseAddressList(address) if err != nil { return probs.InvalidEmail(unparseableEmailDetail) } if len(emails) > 1 { return probs.InvalidEmail(multipleAddressDetail) } splitEmail := strings.SplitN(emails[0].Address, "@", -1) domain := strings.ToLower(splitEmail[len(splitEmail)-1]) var resultMX []string var resultA []net.IP var errMX, errA error var wg sync.WaitGroup wg.Add(2) go func() { resultMX, errMX = resolver.LookupMX(ctx, domain) wg.Done() }() go func() { resultA, errA = resolver.LookupHost(ctx, domain) wg.Done() }() wg.Wait() if errMX != nil { prob := bdns.ProblemDetailsFromDNSError(errMX) prob.Type = probs.InvalidEmailProblem return prob } else if len(resultMX) > 0 { return nil } if errA != nil { prob := bdns.ProblemDetailsFromDNSError(errA) prob.Type = probs.InvalidEmailProblem return prob } else if len(resultA) > 0 { return nil } return probs.InvalidEmail(emptyDNSResponseDetail) }