// ParseOneCertificateFromPEM attempts to parse one PEM encoded certificate object,
// either a raw x509 certificate or a PKCS #7 structure possibly containing
// multiple certificates, from the top of certsPEM, which itself may
// contain multiple PEM encoded certificate objects.
func ParseOneCertificateFromPEM(certsPEM []byte) ([]*x509.Certificate, []byte, error) {
block, rest := pem.Decode(certsPEM)
if block == nil {
return nil, rest, nil
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
pkcs7data, err := pkcs7.ParsePKCS7(block.Bytes)
if err != nil {
return nil, rest, err
}
if pkcs7data.ContentInfo != "SignedData" {
return nil, rest, errors.New("only PKCS #7 Signed Data Content Info supported for certificate parsing")
}
certs := pkcs7data.Content.SignedData.Certificates
if certs == nil {
return nil, rest, errors.New("PKCS #7 structure contains no certificates")
}
return certs, rest, nil
}
var certs = []*x509.Certificate{cert}
return certs, rest, nil
}
// Given a slice of PKCS #7 content infos containing PKCS #12 Safe Bag Data,
// getBags returns those Safe Bags.
func getBags(authenticatedSafe []asn1.RawValue, password []byte) (bags []safeBag, err error) {
for _, contentInfo := range authenticatedSafe {
var safeContents []safeBag
bagContainer, err := pkcs7.ParsePKCS7(contentInfo.FullBytes)
if err != nil {
return nil, err
}
switch {
case bagContainer.ContentInfo == "Data":
if _, err = asn1.Unmarshal(bagContainer.Content.Data, &safeContents); err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
case bagContainer.ContentInfo == "EncryptedData":
data, err := decrypt(bagContainer.Content.EncryptedData.EncryptedContentInfo.ContentEncryptionAlgorithm,
bagContainer.Content.EncryptedData.EncryptedContentInfo.EncryptedContent, password)
if err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
if _, err = asn1.Unmarshal(data, &safeContents); err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
default:
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("Only support for bags encoded in Data and EncryptedData types"))
}
bags = append(bags, safeContents...)
}
return bags, nil
}
// ParseCertificatesDER parses a DER encoding of a certificate object and possibly private key,
// either PKCS #7, PKCS #12, or raw x509.
func ParseCertificatesDER(certsDER []byte, password string) ([]*x509.Certificate, crypto.Signer, error) {
var certs []*x509.Certificate
var key crypto.Signer
certsDER = bytes.TrimSpace(certsDER)
pkcs7data, err := pkcs7.ParsePKCS7(certsDER)
if err != nil {
pkcs12data, err := pkcs12.ParsePKCS12(certsDER, []byte(password))
if err != nil {
certs, err = x509.ParseCertificates(certsDER)
if err != nil {
return nil, nil, cferr.New(cferr.CertificateError, cferr.DecodeFailed)
}
} else {
key = pkcs12data.PrivateKey
certs = pkcs12data.Certificates
}
} else {
if pkcs7data.ContentInfo != "SignedData" {
return nil, nil, cferr.Wrap(cferr.CertificateError, cferr.DecodeFailed, errors.New("can only extract certificates from signed data content info"))
}
certs = pkcs7data.Content.SignedData.Certificates
}
if certs == nil {
return nil, key, cferr.New(cferr.CertificateError, cferr.DecodeFailed)
}
return certs, key, nil
}
// ParsePKCS12 parses a pkcs12 syntax object
// into a container for a private key, certificate(s), and
// version number
func ParsePKCS12(raw, password []byte) (msg *PKCS12, err error) {
msg = new(PKCS12)
password, err = pbkdf.BMPString(password)
if err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
var Pfx pfx
_, err = asn1.Unmarshal(raw, &Pfx)
if err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
if msg.Version = Pfx.Version; msg.Version != 3 {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("Only support for PKCS #12 PFX version 3"))
}
authSafe, err := pkcs7.ParsePKCS7(Pfx.AuthSafe.FullBytes)
if err != nil {
return nil, err
}
if authSafe.ContentInfo != "Data" {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("No support for AuthSafe Format"))
}
var authenticatedSafe []asn1.RawValue
_, err = asn1.Unmarshal(authSafe.Content.Data, &authenticatedSafe)
if err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
if len(authenticatedSafe) != 2 {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("No support for AuthSafe Format"))
}
var bags []safeBag
bags, err = getBags(authenticatedSafe, password)
if err != nil {
return nil, err
}
if len(bags) > 2 || bags == nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("No support for AuthSafe Format"))
}
certs, pkey, err := parseBags(bags, password)
if err != nil {
return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
}
msg.Certificates = certs
msg.PrivateKey = pkey
return
}