tls.go

     1  // Copyright 2017 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build boringcrypto
     6  
     7  // Package fipstls allows control over whether crypto/tls requires FIPS-approved settings.
     8  // This package only exists with GOEXPERIMENT=boringcrypto, but the effects are independent
     9  // of the use of BoringCrypto.
    10  package fipstls
    11  
    12  import (
    13  	"internal/stringslite"
    14  	"sync/atomic"
    15  )
    16  
    17  var required atomic.Bool
    18  
    19  // Force forces crypto/tls to restrict TLS configurations to FIPS-approved settings.
    20  // By design, this call is impossible to undo (except in tests).
    21  //
    22  // Note that this call has an effect even in programs using
    23  // standard crypto (that is, even when Enabled = false).
    24  func Force() {
    25  	required.Store(true)
    26  }
    27  
    28  // Abandon allows non-FIPS-approved settings.
    29  // If called from a non-test binary, it panics.
    30  func Abandon() {
    31  	// Note: Not using boring.UnreachableExceptTests because we want
    32  	// this test to happen even when boring.Enabled = false.
    33  	name := runtime_arg0()
    34  	// Allow _test for Go command, .test for Bazel,
    35  	// NaClMain for NaCl (where all binaries run as NaClMain),
    36  	// and empty string for Windows (where runtime_arg0 can't easily find the name).
    37  	// Since this is an internal package, testing that this isn't used on the
    38  	// other operating systems should suffice to catch any mistakes.
    39  	if !stringslite.HasSuffix(name, "_test") && !stringslite.HasSuffix(name, ".test") && name != "NaClMain" && name != "" {
    40  		panic("fipstls: invalid use of Abandon in " + name)
    41  	}
    42  	required.Store(false)
    43  }
    44  
    45  // provided by runtime
    46  func runtime_arg0() string
    47  
    48  // Required reports whether FIPS-approved settings are required.
    49  func Required() bool {
    50  	return required.Load()
    51  }
    52
View as plain text