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")
)

// ParseRSAPrivateKeyFromPEM parses a PEM encoded PKCS1 or PKCS8 private key
funcParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error) {
varerrerror

// Parse PEM block
varblock*pem.Block
ifblock, _=pem.Decode(key); block==nil {
returnnil, ErrKeyMustBePEMEncoded
 }

varparsedKeyinterface{}
ifparsedKey, err=x509.ParsePKCS1PrivateKey(block.Bytes); err!=nil {
ifparsedKey, err=x509.ParsePKCS8PrivateKey(block.Bytes); err!=nil {
returnnil, err
 }
 }

varpkey*rsa.PrivateKey
varokbool
ifpkey, ok=parsedKey.(*rsa.PrivateKey); !ok {
returnnil, ErrNotRSAPrivateKey
 }

returnpkey, nil
}

// ParseRSAPrivateKeyFromPEMWithPassword parses a PEM encoded PKCS1 or PKCS8 private key protected with password
//
// Deprecated: This function is deprecated and should not be used anymore. It uses the deprecated x509.DecryptPEMBlock
// function, which was deprecated since RFC 1423 is regarded insecure by design. Unfortunately, there is no alternative
// in the Go standard library for now. See https://github.com/golang/go/issues/8860.
funcParseRSAPrivateKeyFromPEMWithPassword(key []byte, passwordstring) (*rsa.PrivateKey, error) {
varerrerror

// Parse PEM block
varblock*pem.Block
ifblock, _=pem.Decode(key); block==nil {
returnnil, ErrKeyMustBePEMEncoded
 }

varparsedKeyinterface{}

varblockDecrypted []byte
ifblockDecrypted, err=x509.DecryptPEMBlock(block, []byte(password)); err!=nil {
returnnil, err
 }

ifparsedKey, err=x509.ParsePKCS1PrivateKey(blockDecrypted); err!=nil {
ifparsedKey, err=x509.ParsePKCS8PrivateKey(blockDecrypted); err!=nil {
returnnil, err
 }
 }

varpkey*rsa.PrivateKey
varokbool
ifpkey, ok=parsedKey.(*rsa.PrivateKey); !ok {
returnnil, ErrNotRSAPrivateKey
 }

returnpkey, nil
}

// ParseRSAPublicKeyFromPEM parses a certificate or a PEM encoded PKCS1 or PKIX public key
funcParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error) {
varerrerror

// Parse PEM block
varblock*pem.Block
ifblock, _=pem.Decode(key); block==nil {
returnnil, ErrKeyMustBePEMEncoded
 }

// Parse the key
varparsedKeyinterface{}
ifparsedKey, err=x509.ParsePKIXPublicKey(block.Bytes); err!=nil {
ifcert, err:=x509.ParseCertificate(block.Bytes); err==nil {
parsedKey=cert.PublicKey
 } else {
ifparsedKey, err=x509.ParsePKCS1PublicKey(block.Bytes); err!=nil {
returnnil, err
 }
 }
 }

varpkey*rsa.PublicKey
varokbool
ifpkey, ok=parsedKey.(*rsa.PublicKey); !ok {
returnnil, ErrNotRSAPublicKey
 }

returnpkey, nil
}