vendor

vendor/github.com/cloudflare/cfssl/crypto/pkcs7/pkcs7.go

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+// Package pkcs7 implements the subset of the CMS PKCS #7 datatype that is typically
+// used to package certificates and CRLs.  Using openssl, every certificate converted
+// to PKCS #7 format from another encoding such as PEM conforms to this implementation.
+// reference: https://www.openssl.org/docs/man1.1.0/apps/crl2pkcs7.html
+//
+//			PKCS #7 Data type, reference: https://tools.ietf.org/html/rfc2315
+//
+// The full pkcs#7 cryptographic message syntax allows for cryptographic enhancements,
+// for example data can be encrypted and signed and then packaged through pkcs#7 to be
+// sent over a network and then verified and decrypted.  It is asn1, and the type of
+// PKCS #7 ContentInfo, which comprises the PKCS #7 structure, is:
+//
+//			ContentInfo ::= SEQUENCE {
+//				contentType ContentType,
+//				content [0] EXPLICIT ANY DEFINED BY contentType OPTIONAL
+//			}
+//
+// There are 6 possible ContentTypes, data, signedData, envelopedData,
+// signedAndEnvelopedData, digestedData, and encryptedData.  Here signedData, Data, and encrypted
+// Data are implemented, as the degenerate case of signedData without a signature is the typical
+// format for transferring certificates and CRLS, and Data and encryptedData are used in PKCS #12
+// formats.
+// The ContentType signedData has the form:
+//
+//
+//			signedData ::= SEQUENCE {
+//				version Version,
+//				digestAlgorithms DigestAlgorithmIdentifiers,
+//				contentInfo ContentInfo,
+//				certificates [0] IMPLICIT ExtendedCertificatesAndCertificates OPTIONAL
+//				crls [1] IMPLICIT CertificateRevocationLists OPTIONAL,
+//				signerInfos SignerInfos
+//			}
+//
+// As of yet signerInfos and digestAlgorithms are not parsed, as they are not relevant to
+// this system's use of PKCS #7 data.  Version is an integer type, note that PKCS #7 is
+// recursive, this second layer of ContentInfo is similar ignored for our degenerate
+// usage.  The ExtendedCertificatesAndCertificates type consists of a sequence of choices
+// between PKCS #6 extended certificates and x509 certificates.  Any sequence consisting
+// of any number of extended certificates is not yet supported in this implementation.
+//
+// The ContentType Data is simply a raw octet string and is parsed directly into a Go []byte slice.
+//
+// The ContentType encryptedData is the most complicated and its form can be gathered by
+// the go type below.  It essentially contains a raw octet string of encrypted data and an
+// algorithm identifier for use in decrypting this data.
+package pkcs7
+
+import (
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+
+	cferr "github.com/cloudflare/cfssl/errors"
+)
+
+// Types used for asn1 Unmarshaling.
+
+type signedData struct {
+	Version          int
+	DigestAlgorithms asn1.RawValue
+	ContentInfo      asn1.RawValue
+	Certificates     asn1.RawValue `asn1:"optional" asn1:"tag:0"`
+	Crls             asn1.RawValue `asn1:"optional"`
+	SignerInfos      asn1.RawValue
+}
+
+type initPKCS7 struct {
+	Raw         asn1.RawContent
+	ContentType asn1.ObjectIdentifier
+	Content     asn1.RawValue `asn1:"tag:0,explicit,optional"`
+}
+
+// Object identifier strings of the three implemented PKCS7 types.
+const (
+	ObjIDData          = "1.2.840.113549.1.7.1"
+	ObjIDSignedData    = "1.2.840.113549.1.7.2"
+	ObjIDEncryptedData = "1.2.840.113549.1.7.6"
+)
+
+// PKCS7 represents the ASN1 PKCS #7 Content type.  It contains one of three
+// possible types of Content objects, as denoted by the object identifier in
+// the ContentInfo field, the other two being nil.  SignedData
+// is the degenerate SignedData Content info without signature used
+// to hold certificates and crls.  Data is raw bytes, and EncryptedData
+// is as defined in PKCS #7 standard.
+type PKCS7 struct {
+	Raw         asn1.RawContent
+	ContentInfo string
+	Content     Content
+}
+
+// Content implements three of the six possible PKCS7 data types.  Only one is non-nil.
+type Content struct {
+	Data          []byte
+	SignedData    SignedData
+	EncryptedData EncryptedData
+}
+
+// SignedData defines the typical carrier of certificates and crls.
+type SignedData struct {
+	Raw          asn1.RawContent
+	Version      int
+	Certificates []*x509.Certificate
+	Crl          *pkix.CertificateList
+}
+
+// Data contains raw bytes.  Used as a subtype in PKCS12.
+type Data struct {
+	Bytes []byte
+}
+
+// EncryptedData contains encrypted data.  Used as a subtype in PKCS12.
+type EncryptedData struct {
+	Raw                  asn1.RawContent
+	Version              int
+	EncryptedContentInfo EncryptedContentInfo
+}
+
+// EncryptedContentInfo is a subtype of PKCS7EncryptedData.
+type EncryptedContentInfo struct {
+	Raw                        asn1.RawContent
+	ContentType                asn1.ObjectIdentifier
+	ContentEncryptionAlgorithm pkix.AlgorithmIdentifier
+	EncryptedContent           []byte `asn1:"tag:0,optional"`
+}
+
+// ParsePKCS7 attempts to parse the DER encoded bytes of a
+// PKCS7 structure.
+func ParsePKCS7(raw []byte) (msg *PKCS7, err error) {
+
+	var pkcs7 initPKCS7
+	_, err = asn1.Unmarshal(raw, &pkcs7)
+	if err != nil {
+		return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+	}
+
+	msg = new(PKCS7)
+	msg.Raw = pkcs7.Raw
+	msg.ContentInfo = pkcs7.ContentType.String()
+	switch {
+	case msg.ContentInfo == ObjIDData:
+		msg.ContentInfo = "Data"
+		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &msg.Content.Data)
+		if err != nil {
+			return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+		}
+	case msg.ContentInfo == ObjIDSignedData:
+		msg.ContentInfo = "SignedData"
+		var signedData signedData
+		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &signedData)
+		if err != nil {
+			return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+		}
+		if len(signedData.Certificates.Bytes) != 0 {
+			msg.Content.SignedData.Certificates, err = x509.ParseCertificates(signedData.Certificates.Bytes)
+			if err != nil {
+				return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+			}
+		}
+		if len(signedData.Crls.Bytes) != 0 {
+			msg.Content.SignedData.Crl, err = x509.ParseDERCRL(signedData.Crls.Bytes)
+			if err != nil {
+				return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+			}
+		}
+		msg.Content.SignedData.Version = signedData.Version
+		msg.Content.SignedData.Raw = pkcs7.Content.Bytes
+	case msg.ContentInfo == ObjIDEncryptedData:
+		msg.ContentInfo = "EncryptedData"
+		var encryptedData EncryptedData
+		_, err = asn1.Unmarshal(pkcs7.Content.Bytes, &encryptedData)
+		if err != nil {
+			return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, err)
+		}
+		if encryptedData.Version != 0 {
+			return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("Only support for PKCS #7 encryptedData version 0"))
+		}
+		msg.Content.EncryptedData = encryptedData
+
+	default:
+		return nil, cferr.Wrap(cferr.CertificateError, cferr.ParseFailed, errors.New("Attempt to parse PKCS# 7 Content not of type data, signed data or encrypted data"))
+	}
+
+	return msg, nil
+
+}