niki/vendor/github.com/golang-jwt/jwt/rsa_utils.go

package jwt

import (
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"errors"
)

var (
	ErrKeyMustBePEMEncoded = errors.New("Invalid Key: Key must be a PEM encoded PKCS1 or PKCS8 key")

	ErrNotRSAPrivateKey = errors.New("Key is not a valid RSA private key")

	ErrNotRSAPublicKey = errors.New("Key is not a valid RSA public key")
)

// Parse PEM encoded PKCS1 or PKCS8 private key

func ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error) {

	var err error

	// Parse PEM block

	var block *pem.Block

	if block, _ = pem.Decode(key); block == nil {

		return nil, ErrKeyMustBePEMEncoded

	}

	var parsedKey interface{}

	if parsedKey, err = x509.ParsePKCS1PrivateKey(block.Bytes); err != nil {

		if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {

			return nil, err

		}

	}

	var pkey *rsa.PrivateKey

	var ok bool

	if pkey, ok = parsedKey.(*rsa.PrivateKey); !ok {

		return nil, ErrNotRSAPrivateKey

	}

	return pkey, nil

}

// Parse PEM encoded PKCS1 or PKCS8 private key protected with password

func ParseRSAPrivateKeyFromPEMWithPassword(key []byte, password string) (*rsa.PrivateKey, error) {

	var err error

	// Parse PEM block

	var block *pem.Block

	if block, _ = pem.Decode(key); block == nil {

		return nil, ErrKeyMustBePEMEncoded

	}

	var parsedKey interface{}

	var blockDecrypted []byte

	if blockDecrypted, err = x509.DecryptPEMBlock(block, []byte(password)); err != nil {

		return nil, err

	}

	if parsedKey, err = x509.ParsePKCS1PrivateKey(blockDecrypted); err != nil {

		if parsedKey, err = x509.ParsePKCS8PrivateKey(blockDecrypted); err != nil {

			return nil, err

		}

	}

	var pkey *rsa.PrivateKey

	var ok bool

	if pkey, ok = parsedKey.(*rsa.PrivateKey); !ok {

		return nil, ErrNotRSAPrivateKey

	}

	return pkey, nil

}

// Parse PEM encoded PKCS1 or PKCS8 public key

func ParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error) {

	var err error

	// Parse PEM block

	var block *pem.Block

	if block, _ = pem.Decode(key); block == nil {

		return nil, ErrKeyMustBePEMEncoded

	}

	// Parse the key

	var parsedKey interface{}

	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {

		if cert, err := x509.ParseCertificate(block.Bytes); err == nil {

			parsedKey = cert.PublicKey

		} else {

			return nil, err

		}

	}

	var pkey *rsa.PublicKey

	var ok bool

	if pkey, ok = parsedKey.(*rsa.PublicKey); !ok {

		return nil, ErrNotRSAPublicKey

	}

	return pkey, nil

}