// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package pkix contains shared, low level structures used for ASN.1 parsing // and serialization of X.509 certificates, CRL and OCSP.
package pkix import ( "encoding/asn1" "encoding/hex" "fmt" "math/big" "time" ) // AlgorithmIdentifier represents the ASN.1 structure of the same name. See RFC // 5280, section 4.1.1.2. type AlgorithmIdentifier struct { Algorithm asn1.ObjectIdentifier Parameters asn1.RawValue `asn1:"optional"` } type RDNSequence []RelativeDistinguishedNameSET var attributeTypeNames = map[string]string{ "2.5.4.6": "C", "2.5.4.10": "O", "2.5.4.11": "OU", "2.5.4.3": "CN", "2.5.4.5": "SERIALNUMBER", "2.5.4.7": "L", "2.5.4.8": "ST", "2.5.4.9": "STREET", "2.5.4.17": "POSTALCODE", } // String returns a string representation of the sequence r, // roughly following the RFC 2253 Distinguished Names syntax. func (r RDNSequence) String() string { s := "" for i := 0; i < len(r); i++ { rdn := r[len(r)-1-i] if i > 0 { s += "," } for j, tv := range rdn { if j > 0 { s += "+" } oidString := tv.Type.String() typeName, ok := attributeTypeNames[oidString] if !ok { derBytes, err := asn1.Marshal(tv.Value) if err == nil { s += oidString + "=#" + hex.EncodeToString(derBytes) continue // No value escaping necessary. } typeName = oidString } valueString := fmt.Sprint(tv.Value) escaped := make([]rune, 0, len(valueString)) for k, c := range valueString { escape := false switch c { case ',', '+', '"', '\\', '<', '>', ';': escape = true case ' ': escape = k == 0 || k == len(valueString)-1 case '#': escape = k == 0 } if escape { escaped = append(escaped, '\\', c) } else { escaped = append(escaped, c) } } s += typeName + "=" + string(escaped) } } return s } type RelativeDistinguishedNameSET []AttributeTypeAndValue // AttributeTypeAndValue mirrors the ASN.1 structure of the same name in // RFC 5280, Section 4.1.2.4. type AttributeTypeAndValue struct { Type asn1.ObjectIdentifier Value interface{} } // AttributeTypeAndValueSET represents a set of ASN.1 sequences of // AttributeTypeAndValue sequences from RFC 2986 (PKCS #10). type AttributeTypeAndValueSET struct { Type asn1.ObjectIdentifier Value [][]AttributeTypeAndValue `asn1:"set"` } // Extension represents the ASN.1 structure of the same name. See RFC // 5280, section 4.2. type Extension struct { Id asn1.ObjectIdentifier Critical bool `asn1:"optional"` Value []byte } // Name represents an X.509 distinguished name. This only includes the common // elements of a DN. Note that Name is only an approximation of the X.509 // structure. If an accurate representation is needed, asn1.Unmarshal the raw // subject or issuer as an RDNSequence. type Name struct { Country, Organization, OrganizationalUnit []string Locality, Province []string StreetAddress, PostalCode []string SerialNumber, CommonName string // Names contains all parsed attributes. When parsing distinguished names, // this can be used to extract non-standard attributes that are not parsed // by this package. When marshaling to RDNSequences, the Names field is // ignored, see ExtraNames. Names []AttributeTypeAndValue // ExtraNames contains attributes to be copied, raw, into any marshaled // distinguished names. Values override any attributes with the same OID. // The ExtraNames field is not populated when parsing, see Names. ExtraNames []AttributeTypeAndValue } // FillFromRDNSequence populates n from the provided RDNSequence. // Multi-entry RDNs are flattened, all entries are added to the // relevant n fields, and the grouping is not preserved. func (n *Name) FillFromRDNSequence(rdns *RDNSequence) { for _, rdn := range *rdns { if len(rdn) == 0 { continue } for _, atv := range rdn { n.Names = append(n.Names, atv) value, ok := atv.Value.(string) if !ok { continue } t := atv.Type if len(t) == 4 && t[0] == 2 && t[1] == 5 && t[2] == 4 { switch t[3] { case 3: n.CommonName = value case 5: n.SerialNumber = value case 6: n.Country = append(n.Country, value) case 7: n.Locality = append(n.Locality, value) case 8: n.Province = append(n.Province, value) case 9: n.StreetAddress = append(n.StreetAddress, value) case 10: n.Organization = append(n.Organization, value) case 11: n.OrganizationalUnit = append(n.OrganizationalUnit, value) case 17: n.PostalCode = append(n.PostalCode, value) } } } } } var ( oidCountry = []int{2, 5, 4, 6} oidOrganization = []int{2, 5, 4, 10} oidOrganizationalUnit = []int{2, 5, 4, 11} oidCommonName = []int{2, 5, 4, 3} oidSerialNumber = []int{2, 5, 4, 5} oidLocality = []int{2, 5, 4, 7} oidProvince = []int{2, 5, 4, 8} oidStreetAddress = []int{2, 5, 4, 9} oidPostalCode = []int{2, 5, 4, 17} ) // appendRDNs appends a relativeDistinguishedNameSET to the given RDNSequence // and returns the new value. The relativeDistinguishedNameSET contains an // attributeTypeAndValue for each of the given values. See RFC 5280, A.1, and // search for AttributeTypeAndValue. func (n Name) appendRDNs(in RDNSequence, values []string, oid asn1.ObjectIdentifier) RDNSequence { if len(values) == 0 || oidInAttributeTypeAndValue(oid, n.ExtraNames) { return in } s := make([]AttributeTypeAndValue, len(values)) for i, value := range values { s[i].Type = oid s[i].Value = value } return append(in, s) } // ToRDNSequence converts n into a single RDNSequence. The following // attributes are encoded as multi-value RDNs: // // - Country // - Organization // - OrganizationalUnit // - Locality // - Province // - StreetAddress // - PostalCode // // Each ExtraNames entry is encoded as an individual RDN. func (n Name) ToRDNSequence() (ret RDNSequence) { ret = n.appendRDNs(ret, n.Country, oidCountry) ret = n.appendRDNs(ret, n.Province, oidProvince) ret = n.appendRDNs(ret, n.Locality, oidLocality) ret = n.appendRDNs(ret, n.StreetAddress, oidStreetAddress) ret = n.appendRDNs(ret, n.PostalCode, oidPostalCode) ret = n.appendRDNs(ret, n.Organization, oidOrganization) ret = n.appendRDNs(ret, n.OrganizationalUnit, oidOrganizationalUnit) if len(n.CommonName) > 0 { ret = n.appendRDNs(ret, []string{n.CommonName}, oidCommonName) } if len(n.SerialNumber) > 0 { ret = n.appendRDNs(ret, []string{n.SerialNumber}, oidSerialNumber) } for _, atv := range n.ExtraNames { ret = append(ret, []AttributeTypeAndValue{atv}) } return ret } // String returns the string form of n, roughly following // the RFC 2253 Distinguished Names syntax. func (n Name) String() string { var rdns RDNSequence // If there are no ExtraNames, surface the parsed value (all entries in // Names) instead. if n.ExtraNames == nil { for _, atv := range n.Names { t := atv.Type if len(t) == 4 && t[0] == 2 && t[1] == 5 && t[2] == 4 { switch t[3] { case 3, 5, 6, 7, 8, 9, 10, 11, 17: // These attributes were already parsed into named fields. continue } } // Place non-standard parsed values at the beginning of the sequence // so they will be at the end of the string. See Issue 39924. rdns = append(rdns, []AttributeTypeAndValue{atv}) } } rdns = append(rdns, n.ToRDNSequence()...) return rdns.String() } // oidInAttributeTypeAndValue reports whether a type with the given OID exists // in atv. func oidInAttributeTypeAndValue(oid asn1.ObjectIdentifier, atv []AttributeTypeAndValue) bool { for _, a := range atv { if a.Type.Equal(oid) { return true } } return false } // CertificateList represents the ASN.1 structure of the same name. See RFC // 5280, section 5.1. Use Certificate.CheckCRLSignature to verify the // signature. type CertificateList struct { TBSCertList TBSCertificateList SignatureAlgorithm AlgorithmIdentifier SignatureValue asn1.BitString } // HasExpired reports whether certList should have been updated by now. func (certList *CertificateList) HasExpired(now time.Time) bool { return !now.Before(certList.TBSCertList.NextUpdate) } // TBSCertificateList represents the ASN.1 structure of the same name. See RFC // 5280, section 5.1. type TBSCertificateList struct { Raw asn1.RawContent Version int `asn1:"optional,default:0"` Signature AlgorithmIdentifier Issuer RDNSequence ThisUpdate time.Time NextUpdate time.Time `asn1:"optional"` RevokedCertificates []RevokedCertificate `asn1:"optional"` Extensions []Extension `asn1:"tag:0,optional,explicit"` } // RevokedCertificate represents the ASN.1 structure of the same name. See RFC // 5280, section 5.1. type RevokedCertificate struct { SerialNumber *big.Int RevocationTime time.Time Extensions []Extension `asn1:"optional"` }