telegraf/internal/tls/config.go

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2018-05-04 23:33:23 +00:00
package tls
import (
"crypto/tls"
"crypto/x509"
"fmt"
"io/ioutil"
)
// ClientConfig represents the standard client TLS config.
type ClientConfig struct {
TLSCA string `toml:"tls_ca"`
TLSCert string `toml:"tls_cert"`
TLSKey string `toml:"tls_key"`
InsecureSkipVerify bool `toml:"insecure_skip_verify"`
// Deprecated in 1.7; use TLS variables above
SSLCA string `toml:"ssl_ca"`
SSLCert string `toml:"ssl_cert"`
SSLKey string `toml:"ssl_ca"`
}
// ServerConfig represents the standard server TLS config.
type ServerConfig struct {
TLSCert string `toml:"tls_cert"`
TLSKey string `toml:"tls_key"`
TLSAllowedCACerts []string `toml:"tls_allowed_cacerts"`
}
// TLSConfig returns a tls.Config, may be nil without error if TLS is not
// configured.
func (c *ClientConfig) TLSConfig() (*tls.Config, error) {
// Support deprecated variable names
if c.TLSCA == "" && c.SSLCA != "" {
c.TLSCA = c.SSLCA
}
if c.TLSCert == "" && c.SSLCert != "" {
c.TLSCert = c.SSLCert
}
if c.TLSKey == "" && c.SSLKey != "" {
c.TLSKey = c.SSLKey
}
// TODO: return default tls.Config; plugins should not call if they don't
// want TLS, this will require using another option to determine. In the
// case of an HTTP plugin, you could use `https`. Other plugins may need
// the dedicated option `TLSEnable`.
if c.TLSCA == "" && c.TLSKey == "" && c.TLSCert == "" && !c.InsecureSkipVerify {
return nil, nil
}
tlsConfig := &tls.Config{
InsecureSkipVerify: c.InsecureSkipVerify,
Renegotiation: tls.RenegotiateNever,
}
if c.TLSCA != "" {
pool, err := makeCertPool([]string{c.TLSCA})
if err != nil {
return nil, err
}
tlsConfig.RootCAs = pool
}
if c.TLSCert != "" && c.TLSKey != "" {
err := loadCertificate(tlsConfig, c.TLSCert, c.TLSKey)
if err != nil {
return nil, err
}
}
return tlsConfig, nil
}
// TLSConfig returns a tls.Config, may be nil without error if TLS is not
// configured.
func (c *ServerConfig) TLSConfig() (*tls.Config, error) {
if c.TLSCert == "" && c.TLSKey == "" && len(c.TLSAllowedCACerts) == 0 {
return nil, nil
}
tlsConfig := &tls.Config{}
if len(c.TLSAllowedCACerts) != 0 {
pool, err := makeCertPool(c.TLSAllowedCACerts)
if err != nil {
return nil, err
}
tlsConfig.ClientCAs = pool
tlsConfig.ClientAuth = tls.RequireAndVerifyClientCert
}
if c.TLSCert != "" && c.TLSKey != "" {
err := loadCertificate(tlsConfig, c.TLSCert, c.TLSKey)
if err != nil {
return nil, err
}
}
return tlsConfig, nil
}
func makeCertPool(certFiles []string) (*x509.CertPool, error) {
pool := x509.NewCertPool()
for _, certFile := range certFiles {
pem, err := ioutil.ReadFile(certFile)
if err != nil {
return nil, fmt.Errorf(
"could not read certificate %q: %v", certFile, err)
}
ok := pool.AppendCertsFromPEM(pem)
if !ok {
return nil, fmt.Errorf(
"could not parse any PEM certificates %q: %v", certFile, err)
}
}
return pool, nil
}
func loadCertificate(config *tls.Config, certFile, keyFile string) error {
cert, err := tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
return fmt.Errorf(
"could not load keypair %s:%s: %v", certFile, keyFile, err)
}
config.Certificates = []tls.Certificate{cert}
config.BuildNameToCertificate()
return nil
}