open-vault/helper/certutil/types.go

430 lines
13 KiB
Go

// Package certutil contains helper functions that are mostly used
// with the PKI backend but can be generally useful. Functionality
// includes helpers for converting a certificate/private key bundle
// between DER and PEM, printing certificate serial numbers, and more.
//
// Functionality specific to the PKI backend includes some types
// and helper methods to make requesting certificates from the
// backend easy.
package certutil
import (
"crypto"
"crypto/tls"
"crypto/x509"
"encoding/pem"
"fmt"
"strings"
)
// Secret is used to attempt to unmarshal a Vault secret
// JSON response, as a convenience
type Secret struct {
Data map[string]interface{} `json:"data"`
}
// The type of of the Private Key referenced in CertBundle
// and ParsedCertBundle. This uses colloquial names rather than
// official names, to eliminate confusion
type PrivateKeyType int
const (
UnknownPrivateKey = iota
RSAPrivateKey
ECPrivateKey
)
// TLSUsage controls whether the intended usage of a *tls.Config
// returned from ParsedCertBundle.GetTLSConfig is for server use,
// client use, or both, which affects which values are set
type TLSUsage int
const (
TLSUnknown TLSUsage = 0
TLSServer TLSUsage = 1 << iota
TLSClient
)
// UserError represents an error generated due to invalid user input
type UserError struct {
Err string
}
func (e UserError) Error() string {
return e.Err
}
// InternalError represents an error generated internally,
// presumably not due to invalid user input
type InternalError struct {
Err string
}
func (e InternalError) Error() string {
return e.Err
}
// CertBundle contains a key type, a PEM-encoded private key,
// a PEM-encoded certificate, and a string-encoded serial number,
// returned from a successful Issue request
type CertBundle struct {
PrivateKeyType string `json:"private_key_type" structs:"private_key_type" mapstructure:"private_key_type"`
Certificate string `json:"certificate" structs:"certificate" mapstructure:"certificate"`
IssuingCA string `json:"issuing_ca" structs:"issuing_ca" mapstructure:"issuing_ca"`
PrivateKey string `json:"private_key" structs:"private_key" mapstructure:"private_key"`
SerialNumber string `json:"serial_number" structs:"serial_number" mapstructure:"serial_number"`
}
// ParsedCertBundle contains a key type, a DER-encoded private key,
// and a DER-encoded certificate
type ParsedCertBundle struct {
PrivateKeyType int
PrivateKeyBytes []byte
PrivateKey crypto.Signer
IssuingCABytes []byte
IssuingCA *x509.Certificate
CertificateBytes []byte
Certificate *x509.Certificate
}
// CSRBundle contains a key type, a PEM-encoded private key,
// and a PEM-encoded CSR
type CSRBundle struct {
PrivateKeyType string `json:"private_key_type" structs:"private_key_type" mapstructure:"private_key_type"`
CSR string `json:"csr" structs:"csr" mapstructure:"csr"`
PrivateKey string `json:"private_key" structs:"private_key" mapstructure:"private_key"`
}
// ParsedCSRBundle contains a key type, a DER-encoded private key,
// and a DER-encoded certificate request
type ParsedCSRBundle struct {
PrivateKeyType int
PrivateKeyBytes []byte
PrivateKey crypto.Signer
CSRBytes []byte
CSR *x509.CertificateRequest
}
// ToParsedCertBundle converts a string-based certificate bundle
// to a byte-based raw certificate bundle
func (c *CertBundle) ToParsedCertBundle() (*ParsedCertBundle, error) {
result := &ParsedCertBundle{}
var err error
var pemBlock *pem.Block
if len(c.PrivateKey) > 0 {
pemBlock, _ = pem.Decode([]byte(c.PrivateKey))
if pemBlock == nil {
return nil, UserError{"Error decoding private key from cert bundle"}
}
result.PrivateKeyBytes = pemBlock.Bytes
switch c.PrivateKeyType {
case "ec":
result.PrivateKeyType = ECPrivateKey
case "rsa":
result.PrivateKeyType = RSAPrivateKey
default:
// Try to figure it out and correct
if _, err := x509.ParseECPrivateKey(pemBlock.Bytes); err == nil {
result.PrivateKeyType = ECPrivateKey
c.PrivateKeyType = "ec"
} else if _, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes); err == nil {
result.PrivateKeyType = RSAPrivateKey
c.PrivateKeyType = "rsa"
} else {
return nil, UserError{fmt.Sprintf("Unknown private key type in bundle: %s", c.PrivateKeyType)}
}
}
result.PrivateKey, err = result.getSigner()
if err != nil {
return nil, UserError{fmt.Sprintf("Error getting signer: %s", err)}
}
}
if len(c.Certificate) > 0 {
pemBlock, _ = pem.Decode([]byte(c.Certificate))
if pemBlock == nil {
return nil, UserError{"Error decoding certificate from cert bundle"}
}
result.CertificateBytes = pemBlock.Bytes
result.Certificate, err = x509.ParseCertificate(result.CertificateBytes)
if err != nil {
return nil, UserError{"Error encountered parsing certificate bytes from raw bundle"}
}
}
if len(c.IssuingCA) > 0 {
pemBlock, _ = pem.Decode([]byte(c.IssuingCA))
if pemBlock == nil {
return nil, UserError{"Error decoding issuing CA from cert bundle"}
}
result.IssuingCABytes = pemBlock.Bytes
result.IssuingCA, err = x509.ParseCertificate(result.IssuingCABytes)
if err != nil {
return nil, UserError{fmt.Sprintf("Error parsing CA certificate: %s", err)}
}
}
if len(c.SerialNumber) == 0 && len(c.Certificate) > 0 {
c.SerialNumber = GetOctalFormatted(result.Certificate.SerialNumber.Bytes(), ":")
}
return result, nil
}
// ToCertBundle converts a byte-based raw DER certificate bundle
// to a PEM-based string certificate bundle
func (p *ParsedCertBundle) ToCertBundle() (*CertBundle, error) {
result := &CertBundle{}
block := pem.Block{
Type: "CERTIFICATE",
}
if p.Certificate != nil {
result.SerialNumber = strings.TrimSpace(GetOctalFormatted(p.Certificate.SerialNumber.Bytes(), ":"))
}
if p.CertificateBytes != nil && len(p.CertificateBytes) > 0 {
block.Bytes = p.CertificateBytes
result.Certificate = strings.TrimSpace(string(pem.EncodeToMemory(&block)))
}
if p.IssuingCABytes != nil && len(p.IssuingCABytes) > 0 {
block.Bytes = p.IssuingCABytes
result.IssuingCA = strings.TrimSpace(string(pem.EncodeToMemory(&block)))
}
if p.PrivateKeyBytes != nil && len(p.PrivateKeyBytes) > 0 {
block.Bytes = p.PrivateKeyBytes
switch p.PrivateKeyType {
case RSAPrivateKey:
result.PrivateKeyType = "rsa"
block.Type = "RSA PRIVATE KEY"
case ECPrivateKey:
result.PrivateKeyType = "ec"
block.Type = "EC PRIVATE KEY"
default:
return nil, InternalError{"Could not determine private key type when creating block"}
}
result.PrivateKey = strings.TrimSpace(string(pem.EncodeToMemory(&block)))
}
return result, nil
}
// GetSigner returns a crypto.Signer corresponding to the private key
// contained in this ParsedCertBundle. The Signer contains a Public() function
// for getting the corresponding public. The Signer can also be
// type-converted to private keys
func (p *ParsedCertBundle) getSigner() (crypto.Signer, error) {
var signer crypto.Signer
var err error
if p.PrivateKeyBytes == nil || len(p.PrivateKeyBytes) == 0 {
return nil, UserError{"Given parsed cert bundle does not have private key information"}
}
switch p.PrivateKeyType {
case ECPrivateKey:
signer, err = x509.ParseECPrivateKey(p.PrivateKeyBytes)
if err != nil {
return nil, UserError{fmt.Sprintf("Unable to parse CA's private EC key: %s", err)}
}
case RSAPrivateKey:
signer, err = x509.ParsePKCS1PrivateKey(p.PrivateKeyBytes)
if err != nil {
return nil, UserError{fmt.Sprintf("Unable to parse CA's private RSA key: %s", err)}
}
default:
return nil, UserError{"Unable to determine type of private key; only RSA and EC are supported"}
}
return signer, nil
}
// ToParsedCSRBundle converts a string-based CSR bundle
// to a byte-based raw CSR bundle
func (c *CSRBundle) ToParsedCSRBundle() (*ParsedCSRBundle, error) {
result := &ParsedCSRBundle{}
var err error
var pemBlock *pem.Block
if len(c.PrivateKey) > 0 {
pemBlock, _ = pem.Decode([]byte(c.PrivateKey))
if pemBlock == nil {
return nil, UserError{"Error decoding private key from cert bundle"}
}
result.PrivateKeyBytes = pemBlock.Bytes
switch c.PrivateKeyType {
case "ec":
result.PrivateKeyType = ECPrivateKey
case "rsa":
result.PrivateKeyType = RSAPrivateKey
default:
// Try to figure it out and correct
if _, err := x509.ParseECPrivateKey(pemBlock.Bytes); err == nil {
result.PrivateKeyType = ECPrivateKey
c.PrivateKeyType = "ec"
} else if _, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes); err == nil {
result.PrivateKeyType = RSAPrivateKey
c.PrivateKeyType = "rsa"
} else {
return nil, UserError{fmt.Sprintf("Unknown private key type in bundle: %s", c.PrivateKeyType)}
}
}
result.PrivateKey, err = result.getSigner()
if err != nil {
return nil, UserError{fmt.Sprintf("Error getting signer: %s", err)}
}
}
if len(c.CSR) > 0 {
pemBlock, _ = pem.Decode([]byte(c.CSR))
if pemBlock == nil {
return nil, UserError{"Error decoding certificate from cert bundle"}
}
result.CSRBytes = pemBlock.Bytes
result.CSR, err = x509.ParseCertificateRequest(result.CSRBytes)
if err != nil {
return nil, UserError{"Error encountered parsing certificate bytes from raw bundle"}
}
}
return result, nil
}
// ToCSRBundle converts a byte-based raw DER certificate bundle
// to a PEM-based string certificate bundle
func (p *ParsedCSRBundle) ToCSRBundle() (*CSRBundle, error) {
result := &CSRBundle{}
block := pem.Block{
Type: "CERTIFICATE REQUEST",
}
if p.CSRBytes != nil && len(p.CSRBytes) > 0 {
block.Bytes = p.CSRBytes
result.CSR = strings.TrimSpace(string(pem.EncodeToMemory(&block)))
}
if p.PrivateKeyBytes != nil && len(p.PrivateKeyBytes) > 0 {
block.Bytes = p.PrivateKeyBytes
switch p.PrivateKeyType {
case RSAPrivateKey:
result.PrivateKeyType = "rsa"
block.Type = "RSA PRIVATE KEY"
case ECPrivateKey:
result.PrivateKeyType = "ec"
block.Type = "EC PRIVATE KEY"
default:
return nil, InternalError{"Could not determine private key type when creating block"}
}
result.PrivateKey = strings.TrimSpace(string(pem.EncodeToMemory(&block)))
}
return result, nil
}
// GetSigner returns a crypto.Signer corresponding to the private key
// contained in this ParsedCSRBundle. The Signer contains a Public() function
// for getting the corresponding public. The Signer can also be
// type-converted to private keys
func (p *ParsedCSRBundle) getSigner() (crypto.Signer, error) {
var signer crypto.Signer
var err error
if p.PrivateKeyBytes == nil || len(p.PrivateKeyBytes) == 0 {
return nil, UserError{"Given parsed cert bundle does not have private key information"}
}
switch p.PrivateKeyType {
case ECPrivateKey:
signer, err = x509.ParseECPrivateKey(p.PrivateKeyBytes)
if err != nil {
return nil, UserError{fmt.Sprintf("Unable to parse CA's private EC key: %s", err)}
}
case RSAPrivateKey:
signer, err = x509.ParsePKCS1PrivateKey(p.PrivateKeyBytes)
if err != nil {
return nil, UserError{fmt.Sprintf("Unable to parse CA's private RSA key: %s", err)}
}
default:
return nil, UserError{"Unable to determine type of private key; only RSA and EC are supported"}
}
return signer, nil
}
// GetTLSConfig returns a TLS config generally suitable for client
// authentiation. The returned TLS config can be modified slightly
// to be made suitable for a server requiring client authentication;
// specifically, you should set the value of ClientAuth in the returned
// config to match your needs.
func (p *ParsedCertBundle) GetTLSConfig(usage TLSUsage) (*tls.Config, error) {
tlsCert := tls.Certificate{
Certificate: [][]byte{},
}
tlsConfig := &tls.Config{
NextProtos: []string{"http/1.1"},
}
if p.Certificate != nil {
tlsCert.Leaf = p.Certificate
}
if p.PrivateKey != nil {
tlsCert.PrivateKey = p.PrivateKey
}
if p.CertificateBytes != nil && len(p.CertificateBytes) > 0 {
tlsCert.Certificate = append(tlsCert.Certificate, p.CertificateBytes)
}
if p.IssuingCABytes != nil && len(p.IssuingCABytes) > 0 {
tlsCert.Certificate = append(tlsCert.Certificate, p.IssuingCABytes)
// Technically we only need one cert, but this doesn't duplicate code
certBundle, err := p.ToCertBundle()
if err != nil {
return nil, fmt.Errorf("Error converting parsed bundle to string bundle when getting TLS config: %s", err)
}
caPool := x509.NewCertPool()
ok := caPool.AppendCertsFromPEM([]byte(certBundle.IssuingCA))
if !ok {
return nil, fmt.Errorf("Could not append CA certificate")
}
if usage&TLSServer > 0 {
tlsConfig.ClientCAs = caPool
tlsConfig.ClientAuth = tls.VerifyClientCertIfGiven
}
if usage&TLSClient > 0 {
tlsConfig.RootCAs = caPool
}
}
if tlsCert.Certificate != nil && len(tlsCert.Certificate) > 0 {
tlsConfig.Certificates = []tls.Certificate{tlsCert}
tlsConfig.BuildNameToCertificate()
}
return tlsConfig, nil
}
// IssueData is a structure that is suitable for marshaling into a request;
// either via JSON, or into a map[string]interface{} via the structs package
type IssueData struct {
TTL string `json:"ttl" structs:"ttl" mapstructure:"ttl"`
CommonName string `json:"common_name" structs:"common_name" mapstructure:"common_name"`
AltNames string `json:"alt_names" structs:"alt_names" mapstructure:"alt_names"`
IPSANs string `json:"ip_sans" structs:"ip_sans" mapstructure:"ip_sans"`
CSR string `json:"csr" structs:"csr" mapstructure:"csr"`
}