azure-container-networking/server/tls/tlscertificate_retriever_li...

104 строки
2.8 KiB
Go

// Copyright 2020 Microsoft. All rights reserved.
package tls
import (
"crypto"
"crypto/x509"
"encoding/pem"
"fmt"
"os"
)
const (
CertLabel = "CERTIFICATE"
PrivateKeyLabel = "PRIVATE KEY"
)
type linuxTlsCertificateRetriever struct {
pemBlock []*pem.Block
settings TlsSettings
}
// GetCertificate Returns the certificate associated with the pem
func (fcert *linuxTlsCertificateRetriever) GetCertificate() (*x509.Certificate, error) {
for _, block := range fcert.pemBlock {
if block.Type == CertLabel {
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, fmt.Errorf("Failed to parse certificate at location %s with error %+v", fcert.settings.TLSCertificatePath, err)
}
if !cert.IsCA {
return cert, nil
}
}
}
return nil, fmt.Errorf("No Certificate block found")
}
// GetPrivateKey Returns the private key associated with the pem
func (fcert *linuxTlsCertificateRetriever) GetPrivateKey() (crypto.PrivateKey, error) {
for _, block := range fcert.pemBlock {
if block.Type == PrivateKeyLabel {
pk, err := x509.ParsePKCS8PrivateKey(block.Bytes)
if err != nil {
return nil, fmt.Errorf("Could not parse private key %+v", err)
}
return pk, nil
}
}
return nil, fmt.Errorf("No private key found in certificate bundle located at %s", fcert.settings.TLSCertificatePath)
}
// ReadFile reads a from disk
func (fcert *linuxTlsCertificateRetriever) readFile() ([]byte, error) {
content, err := os.ReadFile(fcert.settings.TLSCertificatePath)
if err != nil {
return nil, fmt.Errorf("Error reading file from path %s with error: %+v ", fcert.settings.TLSCertificatePath, err)
}
return content, nil
}
// Parses a file to PEM format
func (fcert *linuxTlsCertificateRetriever) parsePEMFile(content []byte) error {
pemBlocks := make([]*pem.Block, 0)
var pemBlock *pem.Block
nextPemBlock := content
for {
pemBlock, nextPemBlock = pem.Decode(nextPemBlock)
if pemBlock == nil {
break
}
pemBlocks = append(pemBlocks, pemBlock)
}
if len(pemBlocks) < 2 {
return fmt.Errorf("Invalid PEM format located at %s", fcert.settings.TLSCertificatePath)
}
fcert.pemBlock = pemBlocks
return nil
}
// NewTlsCertificateRetriever creates a TlsCertificateRetriever
// NewTlsCertificateRetriever depends on the pem being available
// linux users generally store certificates at /etc/ssl/certs/
func NewTlsCertificateRetriever(settings TlsSettings) (TlsCertificateRetriever, error) {
linuxCertStoreRetriever := &linuxTlsCertificateRetriever{
settings: settings,
}
content, err := linuxCertStoreRetriever.readFile()
if err != nil {
return nil, fmt.Errorf("Failed to read file with error %+v", err)
}
if err := linuxCertStoreRetriever.parsePEMFile(content); err != nil {
return nil, fmt.Errorf("Failed to parse PEM file with error %+v", err)
}
return linuxCertStoreRetriever, nil
}