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crypto/x509: add code for dealing with PKIX public keys.

We also have functions for dealing with PKCS#1 private keys. This
change adds functions for PKIX /public/ keys. Most of the time one
won't be parsing them because they usually come in certificates, but
marshaling them happens and I've previously copied the code from
x509.go for this.

R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/5286042
This commit is contained in:
Adam Langley 2011-10-14 15:11:21 -04:00
parent e74dcbeb0f
commit b3812bf6db
4 changed files with 199 additions and 95 deletions

View File

@ -7,6 +7,7 @@ include ../../../Make.inc
TARG=crypto/x509
GOFILES=\
cert_pool.go\
pkcs1.go\
verify.go\
x509.go\

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@ -0,0 +1,122 @@
// 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 x509
import (
"asn1"
"big"
"os"
"crypto/rsa"
)
// pkcs1PrivateKey is a structure which mirrors the PKCS#1 ASN.1 for an RSA private key.
type pkcs1PrivateKey struct {
Version int
N *big.Int
E int
D *big.Int
P *big.Int
Q *big.Int
// We ignore these values, if present, because rsa will calculate them.
Dp *big.Int `asn1:"optional"`
Dq *big.Int `asn1:"optional"`
Qinv *big.Int `asn1:"optional"`
AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional"`
}
type pkcs1AdditionalRSAPrime struct {
Prime *big.Int
// We ignore these values because rsa will calculate them.
Exp *big.Int
Coeff *big.Int
}
// ParsePKCS1PrivateKey returns an RSA private key from its ASN.1 PKCS#1 DER encoded form.
func ParsePKCS1PrivateKey(der []byte) (key *rsa.PrivateKey, err os.Error) {
var priv pkcs1PrivateKey
rest, err := asn1.Unmarshal(der, &priv)
if len(rest) > 0 {
err = asn1.SyntaxError{"trailing data"}
return
}
if err != nil {
return
}
if priv.Version > 1 {
return nil, os.NewError("x509: unsupported private key version")
}
if priv.N.Sign() <= 0 || priv.D.Sign() <= 0 || priv.P.Sign() <= 0 || priv.Q.Sign() <= 0 {
return nil, os.NewError("private key contains zero or negative value")
}
key = new(rsa.PrivateKey)
key.PublicKey = rsa.PublicKey{
E: priv.E,
N: priv.N,
}
key.D = priv.D
key.Primes = make([]*big.Int, 2+len(priv.AdditionalPrimes))
key.Primes[0] = priv.P
key.Primes[1] = priv.Q
for i, a := range priv.AdditionalPrimes {
if a.Prime.Sign() <= 0 {
return nil, os.NewError("private key contains zero or negative prime")
}
key.Primes[i+2] = a.Prime
// We ignore the other two values because rsa will calculate
// them as needed.
}
err = key.Validate()
if err != nil {
return nil, err
}
key.Precompute()
return
}
// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
key.Precompute()
version := 0
if len(key.Primes) > 2 {
version = 1
}
priv := pkcs1PrivateKey{
Version: version,
N: key.N,
E: key.PublicKey.E,
D: key.D,
P: key.Primes[0],
Q: key.Primes[1],
Dp: key.Precomputed.Dp,
Dq: key.Precomputed.Dq,
Qinv: key.Precomputed.Qinv,
}
priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
for i, values := range key.Precomputed.CRTValues {
priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
priv.AdditionalPrimes[i].Exp = values.Exp
priv.AdditionalPrimes[i].Coeff = values.Coeff
}
b, _ := asn1.Marshal(priv)
return b
}
// rsaPublicKey reflects the ASN.1 structure of a PKCS#1 public key.
type rsaPublicKey struct {
N *big.Int
E int
}

View File

@ -20,108 +20,59 @@ import (
"time"
)
// pkcs1PrivateKey is a structure which mirrors the PKCS#1 ASN.1 for an RSA private key.
type pkcs1PrivateKey struct {
Version int
N *big.Int
E int
D *big.Int
P *big.Int
Q *big.Int
// We ignore these values, if present, because rsa will calculate them.
Dp *big.Int `asn1:"optional"`
Dq *big.Int `asn1:"optional"`
Qinv *big.Int `asn1:"optional"`
AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional"`
// pkixPublicKey reflects a PKIX public key structure. See SubjectPublicKeyInfo
// in RFC 3280.
type pkixPublicKey struct {
Algo pkix.AlgorithmIdentifier
BitString asn1.BitString
}
type pkcs1AdditionalRSAPrime struct {
Prime *big.Int
// We ignore these values because rsa will calculate them.
Exp *big.Int
Coeff *big.Int
}
// ParsePKCS1PrivateKey returns an RSA private key from its ASN.1 PKCS#1 DER encoded form.
func ParsePKCS1PrivateKey(der []byte) (key *rsa.PrivateKey, err os.Error) {
var priv pkcs1PrivateKey
rest, err := asn1.Unmarshal(der, &priv)
if len(rest) > 0 {
err = asn1.SyntaxError{"trailing data"}
// ParsePKIXPublicKey parses a DER encoded public key. These values are
// typically found in PEM blocks with "BEGIN PUBLIC KEY".
func ParsePKIXPublicKey(derBytes []byte) (pub interface{}, err os.Error) {
var pki publicKeyInfo
if _, err = asn1.Unmarshal(derBytes, &pki); err != nil {
return
}
if err != nil {
return
algo := getPublicKeyAlgorithmFromOID(pki.Algorithm.Algorithm)
if algo == UnknownPublicKeyAlgorithm {
return nil, os.NewError("ParsePKIXPublicKey: unknown public key algorithm")
}
if priv.Version > 1 {
return nil, os.NewError("x509: unsupported private key version")
}
if priv.N.Sign() <= 0 || priv.D.Sign() <= 0 || priv.P.Sign() <= 0 || priv.Q.Sign() <= 0 {
return nil, os.NewError("private key contains zero or negative value")
}
key = new(rsa.PrivateKey)
key.PublicKey = rsa.PublicKey{
E: priv.E,
N: priv.N,
}
key.D = priv.D
key.Primes = make([]*big.Int, 2+len(priv.AdditionalPrimes))
key.Primes[0] = priv.P
key.Primes[1] = priv.Q
for i, a := range priv.AdditionalPrimes {
if a.Prime.Sign() <= 0 {
return nil, os.NewError("private key contains zero or negative prime")
}
key.Primes[i+2] = a.Prime
// We ignore the other two values because rsa will calculate
// them as needed.
}
err = key.Validate()
if err != nil {
return nil, err
}
key.Precompute()
return
return parsePublicKey(algo, &pki)
}
// MarshalPKCS1PrivateKey converts a private key to ASN.1 DER encoded form.
func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
key.Precompute()
// MarshalPKIXPublicKey serialises a public key to DER-encoded PKIX format.
func MarshalPKIXPublicKey(pub interface{}) ([]byte, os.Error) {
var pubBytes []byte
version := 0
if len(key.Primes) > 2 {
version = 1
switch pub := pub.(type) {
case *rsa.PublicKey:
pubBytes, _ = asn1.Marshal(rsaPublicKey{
N: pub.N,
E: pub.E,
})
default:
return nil, os.NewError("MarshalPKIXPublicKey: unknown public key type")
}
priv := pkcs1PrivateKey{
Version: version,
N: key.N,
E: key.PublicKey.E,
D: key.D,
P: key.Primes[0],
Q: key.Primes[1],
Dp: key.Precomputed.Dp,
Dq: key.Precomputed.Dq,
Qinv: key.Precomputed.Qinv,
pkix := pkixPublicKey{
Algo: pkix.AlgorithmIdentifier{
Algorithm: []int{1, 2, 840, 113549, 1, 1, 1},
// This is a NULL parameters value which is technically
// superfluous, but most other code includes it and, by
// doing this, we match their public key hashes.
Parameters: asn1.RawValue{
Tag: 5,
},
},
BitString: asn1.BitString{
Bytes: pubBytes,
BitLength: 8 * len(pubBytes),
},
}
priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
for i, values := range key.Precomputed.CRTValues {
priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
priv.AdditionalPrimes[i].Exp = values.Exp
priv.AdditionalPrimes[i].Coeff = values.Coeff
}
b, _ := asn1.Marshal(priv)
return b
ret, _ := asn1.Marshal(pkix)
return ret, nil
}
// These structures reflect the ASN.1 structure of X.509 certificates.:
@ -485,11 +436,6 @@ type basicConstraints struct {
MaxPathLen int `asn1:"optional"`
}
type rsaPublicKey struct {
N *big.Int
E int
}
// RFC 5280 4.2.1.4
type policyInformation struct {
Policy asn1.ObjectIdentifier

View File

@ -6,6 +6,7 @@ package x509
import (
"asn1"
"bytes"
"big"
"crypto/dsa"
"crypto/rand"
@ -34,6 +35,40 @@ func TestParsePKCS1PrivateKey(t *testing.T) {
}
}
func TestParsePKIXPublicKey(t *testing.T) {
block, _ := pem.Decode([]byte(pemPublicKey))
pub, err := ParsePKIXPublicKey(block.Bytes)
if err != nil {
t.Errorf("Failed to parse RSA public key: %s", err)
return
}
rsaPub, ok := pub.(*rsa.PublicKey)
if !ok {
t.Errorf("Value returned from ParsePKIXPublicKey was not an RSA public key")
return
}
pubBytes2, err := MarshalPKIXPublicKey(rsaPub)
if err != nil {
t.Errorf("Failed to marshal RSA public key for the second time: %s", err)
return
}
if !bytes.Equal(pubBytes2, block.Bytes) {
t.Errorf("Reserialization of public key didn't match. got %x, want %x", pubBytes2, block.Bytes)
}
}
var pemPublicKey = `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3VoPN9PKUjKFLMwOge6+
wnDi8sbETGIx2FKXGgqtAKpzmem53kRGEQg8WeqRmp12wgp74TGpkEXsGae7RS1k
enJCnma4fii+noGH7R0qKgHvPrI2Bwa9hzsH8tHxpyM3qrXslOmD45EH9SxIDUBJ
FehNdaPbLP1gFyahKMsdfxFJLUvbUycuZSJ2ZnIgeVxwm4qbSvZInL9Iu4FzuPtg
fINKcbbovy1qq4KvPIrXzhbY3PWDc6btxCf3SE0JdE1MCPThntB62/bLMSQ7xdDR
FF53oIpvxe/SCOymfWq/LW849Ytv3Xwod0+wzAP8STXG4HSELS4UedPYeHJJJYcZ
+QIDAQAB
-----END PUBLIC KEY-----
`
var pemPrivateKey = `-----BEGIN RSA PRIVATE KEY-----
MIIBOgIBAAJBALKZD0nEffqM1ACuak0bijtqE2QrI/KLADv7l3kK3ppMyCuLKoF0
fd7Ai2KW5ToIwzFofvJcS/STa6HA5gQenRUCAwEAAQJBAIq9amn00aS0h/CrjXqu