authelia/internal/utils/crypto.go

576 lines
17 KiB
Go

package utils
import (
"bytes"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"errors"
"fmt"
"math/big"
"net"
"os"
"path/filepath"
"strings"
"time"
"github.com/authelia/authelia/v4/internal/configuration/schema"
"github.com/authelia/authelia/v4/internal/logging"
)
// PEMBlockType represent an enum of the existing PEM block types.
type PEMBlockType int
const (
// Certificate block type.
Certificate PEMBlockType = iota
// PrivateKey block type.
PrivateKey
)
// GenerateCertificate generate a certificate given a private key. RSA, Ed25519 and ECDSA are officially supported.
func GenerateCertificate(privateKeyBuilder PrivateKeyBuilder, hosts []string, validFrom time.Time, validFor time.Duration, isCA bool) ([]byte, []byte, error) {
privateKey, err := privateKeyBuilder.Build()
if err != nil {
return nil, nil, fmt.Errorf("unable to build private key: %w", err)
}
notBefore := validFrom
notAfter := validFrom.Add(validFor)
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
if err != nil {
return nil, nil, fmt.Errorf("failed to generate serial number: %v", err)
}
template := x509.Certificate{
SerialNumber: serialNumber,
Subject: pkix.Name{
Organization: []string{"Acme Co"},
},
NotBefore: notBefore,
NotAfter: notAfter,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
BasicConstraintsValid: true,
}
for _, h := range hosts {
if ip := net.ParseIP(h); ip != nil {
template.IPAddresses = append(template.IPAddresses, ip)
} else {
template.DNSNames = append(template.DNSNames, h)
}
}
if isCA {
template.IsCA = true
template.KeyUsage |= x509.KeyUsageCertSign
}
certDERBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(privateKey), privateKey)
if err != nil {
return nil, nil, fmt.Errorf("failed to create certificate: %v", err)
}
certPEMBytes, err := ConvertDERToPEM(certDERBytes, Certificate)
if err != nil {
return nil, nil, fmt.Errorf("failed to convert certificate in DER format into PEM: %v", err)
}
keyDERBytes, err := x509.MarshalPKCS8PrivateKey(privateKey)
if err != nil {
return nil, nil, fmt.Errorf("failed to marshal private key: %v", err)
}
keyPEMBytes, err := ConvertDERToPEM(keyDERBytes, PrivateKey)
if err != nil {
return nil, nil, fmt.Errorf("faile to convert certificate in DER format into PEM: %v", err)
}
return certPEMBytes, keyPEMBytes, nil
}
// ConvertDERToPEM convert certificate in DER format into PEM format.
func ConvertDERToPEM(der []byte, blockType PEMBlockType) ([]byte, error) {
var buf bytes.Buffer
var blockTypeStr string
switch blockType {
case Certificate:
blockTypeStr = "CERTIFICATE"
case PrivateKey:
blockTypeStr = "PRIVATE KEY"
default:
return nil, fmt.Errorf("unknown PEM block type %d", blockType)
}
if err := pem.Encode(&buf, &pem.Block{Type: blockTypeStr, Bytes: der}); err != nil {
return nil, fmt.Errorf("failed to encode DER data into PEM: %v", err)
}
return buf.Bytes(), nil
}
func publicKey(privateKey any) any {
switch k := privateKey.(type) {
case *rsa.PrivateKey:
return &k.PublicKey
case *ecdsa.PrivateKey:
return &k.PublicKey
case ed25519.PrivateKey:
return k.Public().(ed25519.PublicKey)
default:
return nil
}
}
// PrivateKeyBuilder interface for a private key builder.
type PrivateKeyBuilder interface {
Build() (any, error)
}
// RSAKeyBuilder builder of RSA private key.
type RSAKeyBuilder struct {
keySizeInBits int
}
// WithKeySize configure the key size to use with RSA.
func (rkb RSAKeyBuilder) WithKeySize(bits int) RSAKeyBuilder {
rkb.keySizeInBits = bits
return rkb
}
// Build a RSA private key.
func (rkb RSAKeyBuilder) Build() (any, error) {
return rsa.GenerateKey(rand.Reader, rkb.keySizeInBits)
}
// Ed25519KeyBuilder builder of Ed25519 private key.
type Ed25519KeyBuilder struct{}
// Build an Ed25519 private key.
func (ekb Ed25519KeyBuilder) Build() (any, error) {
_, priv, err := ed25519.GenerateKey(rand.Reader)
return priv, err
}
// ECDSAKeyBuilder builder of ECDSA private key.
type ECDSAKeyBuilder struct {
curve elliptic.Curve
}
// WithCurve configure the curve to use for the ECDSA private key.
func (ekb ECDSAKeyBuilder) WithCurve(curve elliptic.Curve) ECDSAKeyBuilder {
ekb.curve = curve
return ekb
}
// Build an ECDSA private key.
func (ekb ECDSAKeyBuilder) Build() (any, error) {
return ecdsa.GenerateKey(ekb.curve, rand.Reader)
}
// ParseX509FromPEM parses PEM bytes and returns a PKCS key.
func ParseX509FromPEM(data []byte) (key any, err error) {
block, _ := pem.Decode(data)
if block == nil {
return nil, errors.New("failed to parse PEM block containing the key")
}
switch block.Type {
case BlockTypeRSAPrivateKey:
key, err = x509.ParsePKCS1PrivateKey(block.Bytes)
case BlockTypeECDSAPrivateKey:
key, err = x509.ParseECPrivateKey(block.Bytes)
case BlockTypePKCS8PrivateKey:
key, err = x509.ParsePKCS8PrivateKey(block.Bytes)
case BlockTypeRSAPublicKey:
key, err = x509.ParsePKCS1PublicKey(block.Bytes)
case BlockTypePKIXPublicKey:
key, err = x509.ParsePKIXPublicKey(block.Bytes)
case BlockTypeCertificate:
key, err = x509.ParseCertificate(block.Bytes)
default:
return nil, fmt.Errorf("unknown block type: %s", block.Type)
}
if err != nil {
return nil, err
}
return key, nil
}
// CastX509AsCertificate converts an interface to an *x509.Certificate.
func CastX509AsCertificate(c any) (certificate *x509.Certificate, ok bool) {
switch t := c.(type) {
case x509.Certificate:
return &t, true
case *x509.Certificate:
return t, true
default:
return nil, false
}
}
// IsX509PrivateKey returns true if the provided interface is an rsa.PrivateKey, ecdsa.PrivateKey, or ed25519.PrivateKey.
func IsX509PrivateKey(i any) bool {
switch i.(type) {
case rsa.PrivateKey, *rsa.PrivateKey, ecdsa.PrivateKey, *ecdsa.PrivateKey, ed25519.PrivateKey, *ed25519.PrivateKey:
return true
default:
return false
}
}
// NewTLSConfig generates a tls.Config from a schema.TLSConfig and a x509.CertPool.
func NewTLSConfig(config *schema.TLSConfig, certPool *x509.CertPool) (tlsConfig *tls.Config) {
var certificates []tls.Certificate
if config.CertificateChain.HasCertificates() && config.PrivateKey != nil {
certificates = []tls.Certificate{
{
Certificate: config.CertificateChain.CertificatesRaw(),
Leaf: config.CertificateChain.Leaf(),
PrivateKey: config.PrivateKey,
},
}
}
return &tls.Config{
ServerName: config.ServerName,
InsecureSkipVerify: config.SkipVerify, //nolint:gosec // Informed choice by user. Off by default.
MinVersion: config.MinimumVersion.MinVersion(),
MaxVersion: config.MinimumVersion.MaxVersion(),
RootCAs: certPool,
Certificates: certificates,
}
}
// NewX509CertPool generates a x509.CertPool from the system PKI and the directory specified.
func NewX509CertPool(directory string) (certPool *x509.CertPool, warnings []error, errors []error) {
certPool, err := x509.SystemCertPool()
if err != nil {
warnings = append(warnings, fmt.Errorf("could not load system certificate pool which may result in untrusted certificate issues: %v", err))
certPool = x509.NewCertPool()
}
logger := logging.Logger()
logger.Tracef("Starting scan of directory %s for certificates", directory)
if directory != "" {
certsFileInfo, err := os.ReadDir(directory)
if err != nil {
errors = append(errors, fmt.Errorf("could not read certificates from directory %v", err))
} else {
for _, certFileInfo := range certsFileInfo {
nameLower := strings.ToLower(certFileInfo.Name())
if !certFileInfo.IsDir() && (strings.HasSuffix(nameLower, ".cer") || strings.HasSuffix(nameLower, ".crt") || strings.HasSuffix(nameLower, ".pem")) {
certPath := filepath.Join(directory, certFileInfo.Name())
logger.Tracef("Found possible cert %s, attempting to add it to the pool", certPath)
certBytes, err := os.ReadFile(certPath)
if err != nil {
errors = append(errors, fmt.Errorf("could not read certificate %v", err))
} else if ok := certPool.AppendCertsFromPEM(certBytes); !ok {
errors = append(errors, fmt.Errorf("could not import certificate %s", certFileInfo.Name()))
}
}
}
}
}
logger.Tracef("Finished scan of directory %s for certificates", directory)
return certPool, warnings, errors
}
// WriteCertificateBytesToPEM writes a certificate/csr to a file in the PEM format.
func WriteCertificateBytesToPEM(cert []byte, path string, csr bool) (err error) {
out, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return fmt.Errorf("failed to open %s for writing: %w", path, err)
}
blockType := BlockTypeCertificate
if csr {
blockType = BlockTypeCertificateRequest
}
if err = pem.Encode(out, &pem.Block{Bytes: cert, Type: blockType}); err != nil {
_ = out.Close()
return err
}
return out.Close()
}
// WriteKeyToPEM writes a key that can be encoded as a PEM to a file in the PEM format.
func WriteKeyToPEM(key any, path string, pkcs8 bool) (err error) {
pemBlock, err := PEMBlockFromX509Key(key, pkcs8)
if err != nil {
return err
}
out, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return fmt.Errorf("failed to open %s for writing: %w", path, err)
}
if err = pem.Encode(out, pemBlock); err != nil {
_ = out.Close()
return err
}
return out.Close()
}
// PEMBlockFromX509Key turns a PublicKey or PrivateKey into a pem.Block.
func PEMBlockFromX509Key(key any, pkcs8 bool) (pemBlock *pem.Block, err error) {
var (
data []byte
blockType string
)
switch k := key.(type) {
case *rsa.PrivateKey:
if pkcs8 {
blockType = BlockTypePKCS8PrivateKey
data, err = x509.MarshalPKCS8PrivateKey(key)
break
}
blockType = BlockTypeRSAPrivateKey
data = x509.MarshalPKCS1PrivateKey(k)
case *ecdsa.PrivateKey:
if pkcs8 {
blockType = BlockTypePKCS8PrivateKey
data, err = x509.MarshalPKCS8PrivateKey(key)
break
}
blockType = BlockTypeECDSAPrivateKey
data, err = x509.MarshalECPrivateKey(k)
case ed25519.PrivateKey:
blockType = BlockTypePKCS8PrivateKey
data, err = x509.MarshalPKCS8PrivateKey(k)
case *rsa.PublicKey:
if pkcs8 {
blockType = BlockTypePKIXPublicKey
data, err = x509.MarshalPKIXPublicKey(key)
break
}
blockType = BlockTypeRSAPublicKey
data = x509.MarshalPKCS1PublicKey(k)
case *ecdsa.PublicKey, ed25519.PublicKey:
blockType = BlockTypePKIXPublicKey
data, err = x509.MarshalPKIXPublicKey(k)
default:
err = fmt.Errorf("failed to match key type: %T", k)
}
if err != nil {
return nil, fmt.Errorf("failed to marshal key: %w", err)
}
return &pem.Block{
Type: blockType,
Bytes: data,
}, nil
}
// KeySigAlgorithmFromString returns a x509.PublicKeyAlgorithm and x509.SignatureAlgorithm given a keyAlgorithm and signatureAlgorithm string.
func KeySigAlgorithmFromString(keyAlgorithm, signatureAlgorithm string) (keyAlg x509.PublicKeyAlgorithm, sigAlg x509.SignatureAlgorithm) {
keyAlg = PublicKeyAlgorithmFromString(keyAlgorithm)
if keyAlg == x509.UnknownPublicKeyAlgorithm {
return x509.UnknownPublicKeyAlgorithm, x509.UnknownSignatureAlgorithm
}
switch keyAlg {
case x509.RSA:
return keyAlg, RSASignatureAlgorithmFromString(signatureAlgorithm)
case x509.ECDSA:
return keyAlg, ECDSASignatureAlgorithmFromString(signatureAlgorithm)
case x509.Ed25519:
return keyAlg, x509.PureEd25519
default:
return keyAlg, x509.UnknownSignatureAlgorithm
}
}
// PublicKeyAlgorithmFromString returns a x509.PublicKeyAlgorithm given an appropriate string.
func PublicKeyAlgorithmFromString(algorithm string) (alg x509.PublicKeyAlgorithm) {
switch strings.ToUpper(algorithm) {
case KeyAlgorithmRSA:
return x509.RSA
case KeyAlgorithmECDSA:
return x509.ECDSA
case KeyAlgorithmEd25519:
return x509.Ed25519
default:
return x509.UnknownPublicKeyAlgorithm
}
}
// RSASignatureAlgorithmFromString returns a x509.SignatureAlgorithm for the RSA x509.PublicKeyAlgorithm given an
// algorithm string.
func RSASignatureAlgorithmFromString(algorithm string) (alg x509.SignatureAlgorithm) {
switch strings.ToUpper(algorithm) {
case HashAlgorithmSHA1:
return x509.SHA1WithRSA
case HashAlgorithmSHA256:
return x509.SHA256WithRSA
case HashAlgorithmSHA384:
return x509.SHA384WithRSA
case HashAlgorithmSHA512:
return x509.SHA512WithRSA
default:
return x509.UnknownSignatureAlgorithm
}
}
// ECDSASignatureAlgorithmFromString returns a x509.SignatureAlgorithm for the ECDSA x509.PublicKeyAlgorithm given an
// algorithm string.
func ECDSASignatureAlgorithmFromString(algorithm string) (alg x509.SignatureAlgorithm) {
switch strings.ToUpper(algorithm) {
case HashAlgorithmSHA1:
return x509.ECDSAWithSHA1
case HashAlgorithmSHA256:
return x509.ECDSAWithSHA256
case HashAlgorithmSHA384:
return x509.ECDSAWithSHA384
case HashAlgorithmSHA512:
return x509.ECDSAWithSHA512
default:
return x509.UnknownSignatureAlgorithm
}
}
// EllipticCurveFromString turns a string into an elliptic.Curve.
func EllipticCurveFromString(curveString string) (curve elliptic.Curve) {
switch strings.ToUpper(curveString) {
case EllipticCurveAltP224, EllipticCurveP224:
return elliptic.P224()
case EllipticCurveAltP256, EllipticCurveP256:
return elliptic.P256()
case EllipticCurveAltP384, EllipticCurveP384:
return elliptic.P384()
case EllipticCurveAltP521, EllipticCurveP521:
return elliptic.P521()
default:
return nil
}
}
// PublicKeyFromPrivateKey returns a PublicKey when provided with a PrivateKey.
func PublicKeyFromPrivateKey(privateKey any) (publicKey any) {
switch k := privateKey.(type) {
case *rsa.PrivateKey:
return &k.PublicKey
case *ecdsa.PrivateKey:
return &k.PublicKey
case ed25519.PrivateKey:
return k.Public().(ed25519.PublicKey)
default:
return nil
}
}
// X509ParseKeyUsage parses a list of key usages. If provided with an empty list returns a default of Key Encipherment
// and Digital Signature unless ca is true in which case it returns Cert Sign.
func X509ParseKeyUsage(keyUsages []string, ca bool) (keyUsage x509.KeyUsage) {
if len(keyUsages) == 0 {
keyUsage = x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature
if ca {
keyUsage |= x509.KeyUsageCertSign
}
return keyUsage
}
for _, keyUsageString := range keyUsages {
switch strings.ToLower(keyUsageString) {
case "digitalsignature", "digital_signature":
keyUsage |= x509.KeyUsageDigitalSignature
case "keyencipherment", "key_encipherment":
keyUsage |= x509.KeyUsageKeyEncipherment
case "dataencipherment", "data_encipherment":
keyUsage |= x509.KeyUsageDataEncipherment
case "keyagreement", "key_agreement":
keyUsage |= x509.KeyUsageKeyAgreement
case "certsign", "cert_sign", "certificatesign", "certificate_sign":
keyUsage |= x509.KeyUsageCertSign
case "crlsign", "crl_sign":
keyUsage |= x509.KeyUsageCRLSign
case "encipheronly", "encipher_only":
keyUsage |= x509.KeyUsageEncipherOnly
case "decipheronly", "decipher_only":
keyUsage |= x509.KeyUsageDecipherOnly
}
}
return keyUsage
}
// X509ParseExtendedKeyUsage parses a list of extended key usages. If provided with an empty list returns a default of
// Server Auth unless ca is true in which case it returns a default of Any.
func X509ParseExtendedKeyUsage(extKeyUsages []string, ca bool) (extKeyUsage []x509.ExtKeyUsage) {
if len(extKeyUsages) == 0 {
if ca {
extKeyUsage = []x509.ExtKeyUsage{x509.ExtKeyUsageAny}
} else {
extKeyUsage = []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}
}
return extKeyUsage
}
loop:
for _, extKeyUsageString := range extKeyUsages {
switch strings.ToLower(extKeyUsageString) {
case "any":
extKeyUsage = []x509.ExtKeyUsage{x509.ExtKeyUsageAny}
break loop
case "serverauth", "server_auth":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageServerAuth)
case "clientauth", "client_auth":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageClientAuth)
case "codesigning", "code_signing":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageCodeSigning)
case "emailprotection", "email_protection":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageEmailProtection)
case "ipsecendsystem", "ipsec_endsystem", "ipsec_end_system":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageIPSECEndSystem)
case "ipsectunnel", "ipsec_tunnel":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageIPSECTunnel)
case "ipsecuser", "ipsec_user":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageIPSECUser)
case "ocspsigning", "ocsp_signing":
extKeyUsage = append(extKeyUsage, x509.ExtKeyUsageOCSPSigning)
}
}
return extKeyUsage
}