open-vault/helper/certutil/helpers.go
2016-04-13 14:38:29 -05:00

299 lines
9 KiB
Go

package certutil
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/sha1"
"crypto/x509"
"encoding/json"
"encoding/pem"
"fmt"
"math/big"
"strconv"
"strings"
"github.com/mitchellh/mapstructure"
)
// GetOctalFormatted returns the byte buffer formatted in octal with
// the specified separator between bytes.
// FIXME: where did I originally copy this code from? This ain't octal, it's hex.
func GetOctalFormatted(buf []byte, sep string) string {
var ret bytes.Buffer
for _, cur := range buf {
if ret.Len() > 0 {
fmt.Fprintf(&ret, sep)
}
fmt.Fprintf(&ret, "%02x", cur)
}
return ret.String()
}
func ParseHexFormatted(in, sep string) []byte {
var ret bytes.Buffer
var err error
var inBits int64
inBytes := strings.Split(in, sep)
for _, inByte := range inBytes {
if inBits, err = strconv.ParseInt(inByte, 16, 8); err != nil {
return nil
} else {
ret.WriteByte(byte(inBits))
}
}
return ret.Bytes()
}
// GetSubjKeyID returns the subject key ID, e.g. the SHA1 sum
// of the marshaled public key
func GetSubjKeyID(privateKey crypto.Signer) ([]byte, error) {
if privateKey == nil {
return nil, InternalError{"passed-in private key is nil"}
}
marshaledKey, err := x509.MarshalPKIXPublicKey(privateKey.Public())
if err != nil {
return nil, InternalError{fmt.Sprintf("error marshalling public key: %s", err)}
}
subjKeyID := sha1.Sum(marshaledKey)
return subjKeyID[:], nil
}
// ParsePKIMap takes a map (for instance, the Secret.Data
// returned from the PKI backend) and returns a ParsedCertBundle.
func ParsePKIMap(data map[string]interface{}) (*ParsedCertBundle, error) {
result := &CertBundle{}
err := mapstructure.Decode(data, result)
if err != nil {
return nil, UserError{err.Error()}
}
return result.ToParsedCertBundle()
}
// ParsePKIJSON takes a JSON-encoded string and returns a ParsedCertBundle.
//
// This can be either the output of an
// issue call from the PKI backend or just its data member; or,
// JSON not coming from the PKI backend.
func ParsePKIJSON(input []byte) (*ParsedCertBundle, error) {
result := &CertBundle{}
err := json.Unmarshal(input, &result)
if err == nil {
return result.ToParsedCertBundle()
}
var secret Secret
err = json.Unmarshal(input, &secret)
if err == nil {
return ParsePKIMap(secret.Data)
}
return nil, UserError{"unable to parse out of either secret data or a secret object"}
}
// ParsePEMBundle takes a string of concatenated PEM-format certificate
// and private key values and decodes/parses them, checking validity along
// the way. There must be at max two certificates (a certificate and its
// issuing certificate) and one private key.
func ParsePEMBundle(pemBundle string) (*ParsedCertBundle, error) {
if len(pemBundle) == 0 {
return nil, UserError{"empty pem bundle"}
}
pemBytes := []byte(pemBundle)
var pemBlock *pem.Block
parsedBundle := &ParsedCertBundle{}
for {
pemBlock, pemBytes = pem.Decode(pemBytes)
if pemBlock == nil {
return nil, UserError{"no data found"}
}
if signer, err := x509.ParseECPrivateKey(pemBlock.Bytes); err == nil {
if parsedBundle.PrivateKeyType != UnknownPrivateKey {
return nil, UserError{"more than one private key given; provide only one private key in the bundle"}
}
parsedBundle.PrivateKeyFormat = ECBlock
parsedBundle.PrivateKeyType = ECPrivateKey
parsedBundle.PrivateKeyBytes = pemBlock.Bytes
parsedBundle.PrivateKey = signer
} else if signer, err := x509.ParsePKCS1PrivateKey(pemBlock.Bytes); err == nil {
if parsedBundle.PrivateKeyType != UnknownPrivateKey {
return nil, UserError{"more than one private key given; provide only one private key in the bundle"}
}
parsedBundle.PrivateKeyType = RSAPrivateKey
parsedBundle.PrivateKeyFormat = PKCS1Block
parsedBundle.PrivateKeyBytes = pemBlock.Bytes
parsedBundle.PrivateKey = signer
} else if signer, err := x509.ParsePKCS8PrivateKey(pemBlock.Bytes); err == nil {
parsedBundle.PrivateKeyFormat = PKCS8Block
if parsedBundle.PrivateKeyType != UnknownPrivateKey {
return nil, UserError{"More than one private key given; provide only one private key in the bundle"}
}
switch signer := signer.(type) {
case *rsa.PrivateKey:
parsedBundle.PrivateKey = signer
parsedBundle.PrivateKeyType = RSAPrivateKey
parsedBundle.PrivateKeyBytes = pemBlock.Bytes
case *ecdsa.PrivateKey:
parsedBundle.PrivateKey = signer
parsedBundle.PrivateKeyType = ECPrivateKey
parsedBundle.PrivateKeyBytes = pemBlock.Bytes
}
} else if certificates, err := x509.ParseCertificates(pemBlock.Bytes); err == nil {
switch len(certificates) {
case 0:
return nil, UserError{"pem block cannot be decoded to a private key or certificate"}
case 1:
if parsedBundle.Certificate != nil {
switch {
// We just found the issuing CA
case bytes.Equal(parsedBundle.Certificate.AuthorityKeyId, certificates[0].SubjectKeyId) && certificates[0].IsCA:
parsedBundle.IssuingCABytes = pemBlock.Bytes
parsedBundle.IssuingCA = certificates[0]
// Our saved certificate is actually the issuing CA
case bytes.Equal(parsedBundle.Certificate.SubjectKeyId, certificates[0].AuthorityKeyId) && parsedBundle.Certificate.IsCA:
parsedBundle.IssuingCA = parsedBundle.Certificate
parsedBundle.IssuingCABytes = parsedBundle.CertificateBytes
parsedBundle.CertificateBytes = pemBlock.Bytes
parsedBundle.Certificate = certificates[0]
}
} else {
switch {
// If this case isn't correct, the caller needs to assign
// the values to Certificate/CertificateBytes; assumptions
// made here will not be valid for all cases.
case certificates[0].IsCA:
parsedBundle.IssuingCABytes = pemBlock.Bytes
parsedBundle.IssuingCA = certificates[0]
default:
parsedBundle.CertificateBytes = pemBlock.Bytes
parsedBundle.Certificate = certificates[0]
}
}
default:
return nil, UserError{"too many certificates given; provide a maximum of two certificates in the bundle"}
}
}
if len(pemBytes) == 0 {
break
}
}
return parsedBundle, nil
}
// GeneratePrivateKey generates a private key with the specified type and key bits
func GeneratePrivateKey(keyType string, keyBits int, container ParsedPrivateKeyContainer) error {
var err error
var privateKeyType PrivateKeyType
var privateKeyBytes []byte
var privateKey crypto.Signer
switch keyType {
case "rsa":
privateKeyType = RSAPrivateKey
privateKey, err = rsa.GenerateKey(rand.Reader, keyBits)
if err != nil {
return InternalError{Err: fmt.Sprintf("error generating RSA private key: %v", err)}
}
privateKeyBytes = x509.MarshalPKCS1PrivateKey(privateKey.(*rsa.PrivateKey))
case "ec":
privateKeyType = ECPrivateKey
var curve elliptic.Curve
switch keyBits {
case 224:
curve = elliptic.P224()
case 256:
curve = elliptic.P256()
case 384:
curve = elliptic.P384()
case 521:
curve = elliptic.P521()
default:
return UserError{Err: fmt.Sprintf("unsupported bit length for EC key: %d", keyBits)}
}
privateKey, err = ecdsa.GenerateKey(curve, rand.Reader)
if err != nil {
return InternalError{Err: fmt.Sprintf("error generating EC private key: %v", err)}
}
privateKeyBytes, err = x509.MarshalECPrivateKey(privateKey.(*ecdsa.PrivateKey))
if err != nil {
return InternalError{Err: fmt.Sprintf("error marshalling EC private key: %v", err)}
}
default:
return UserError{Err: fmt.Sprintf("unknown key type: %s", keyType)}
}
container.SetParsedPrivateKey(privateKey, privateKeyType, privateKeyBytes)
return nil
}
// GenerateSerialNumber generates a serial number suitable for a certificate
func GenerateSerialNumber() (*big.Int, error) {
serial, err := rand.Int(rand.Reader, (&big.Int{}).Exp(big.NewInt(2), big.NewInt(159), nil))
if err != nil {
return nil, InternalError{Err: fmt.Sprintf("error generating serial number: %v", err)}
}
return serial, nil
}
// ComparePublicKeys compares two public keys and returns true if they match
func ComparePublicKeys(key1Iface, key2Iface crypto.PublicKey) (bool, error) {
switch key1Iface.(type) {
case *rsa.PublicKey:
key1 := key1Iface.(*rsa.PublicKey)
key2, ok := key2Iface.(*rsa.PublicKey)
if !ok {
return false, fmt.Errorf("key types do not match: %T and %T", key1Iface, key2Iface)
}
if key1.N.Cmp(key2.N) != 0 ||
key1.E != key2.E {
return false, nil
}
return true, nil
case *ecdsa.PublicKey:
key1 := key1Iface.(*ecdsa.PublicKey)
key2, ok := key2Iface.(*ecdsa.PublicKey)
if !ok {
return false, fmt.Errorf("key types do not match: %T and %T", key1Iface, key2Iface)
}
if key1.X.Cmp(key2.X) != 0 ||
key1.Y.Cmp(key2.Y) != 0 {
return false, nil
}
key1Params := key1.Params()
key2Params := key2.Params()
if key1Params.P.Cmp(key2Params.P) != 0 ||
key1Params.N.Cmp(key2Params.N) != 0 ||
key1Params.B.Cmp(key2Params.B) != 0 ||
key1Params.Gx.Cmp(key2Params.Gx) != 0 ||
key1Params.Gy.Cmp(key2Params.Gy) != 0 ||
key1Params.BitSize != key2Params.BitSize {
return false, nil
}
return true, nil
default:
return false, fmt.Errorf("cannot compare key with type %T", key1Iface)
}
}