go_S-MIME/cms/protocol/contentinfo.go

56 lines
1.3 KiB
Go

// Package protocol implemets parts of cryptographic message syntax RFC 5652.
// This package is mostly for handling of the asn1 sturctures of cms. For
// de/encryption and signing/verfiying use to package cms.
package protocol
import (
"encoding/asn1"
"fmt"
asn "git.ma-al.com/goc_marek/go_S-MIME/asn1"
"git.ma-al.com/goc_marek/go_S-MIME/b64"
)
// ContentInfo ::= SEQUENCE {
// contentType ContentType,
// content [0] EXPLICIT ANY DEFINED BY contentType }
//
// ContentType ::= OBJECT IDENTIFIER
type ContentInfo struct {
ContentType asn1.ObjectIdentifier
Content asn1.RawValue `asn1:"explicit,tag:0"`
}
// ParseContentInfo parses DER-encoded ASN.1 data and returns ContentInfo.
func ParseContentInfo(der []byte) (ci ContentInfo, err error) {
if err != nil {
return
}
var rest []byte
if rest, err = asn.Unmarshal(der, &ci); err != nil {
return
}
if len(rest) > 0 {
fmt.Println(ErrTrailingData)
//err = ErrTrailingData
}
return
}
// DER returns the DER-encoded ASN.1 data.
func (ci ContentInfo) DER() ([]byte, error) {
return asn.Marshal(ci)
}
// Base64 encodes the DER-encoded ASN.1 data in base64 for use in S/MIME.
func (ci ContentInfo) Base64() ([]byte, error) {
der, err := ci.DER()
if err != nil {
return nil, err
}
return b64.EncodeBase64(der)
}