goc_marek/go_S-MIME
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Added support for ECDH in enveloped data with ECDSA certificates.

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- fixed parsing of choice(was compatible with Apple mail.app which tagged kari explicitly)
- minor fixes
This commit is contained in:
InfiniteLoopSpace 2018-12-10 17:18:29 +01:00
parent 58514b0041
commit 5f34d82562
15 changed files with 702 additions and 168 deletions
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2
README.md
View File

@ -19,7 +19,7 @@ It supports enveloped data with AES in CBC mode. Decryption also works with (3)D
This is covered in
- Cryptographic Message Syntax (CMS) Authenticated-Enveloped-Data Content Type [rfc5083](https://tools.ietf.org/html/rfc5083)
- Using ChaCha20-Poly1305 Authenticated Encryption in the Cryptographic Message Syntax (CMS) [rfc8103](https://tools.ietf.org/html/rfc8103)
- Using AES-CCM and AES-GCM Authenticated Encryption in the Cryptographic Message Syntax (CMS) [rfc5084](https://tools.ietf.org/html/rfc 5084)
- Using AES-CCM and AES-GCM Authenticated Encryption in the Cryptographic Message Syntax (CMS) [rfc5084](https://tools.ietf.org/html/rfc5084)
## Examples

18
asn1/asn1.go
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@ -760,7 +760,7 @@ func parseField(v reflect.Value, bytes []byte, initOffset int, params fieldParam
if err != nil {
return
}
if params.explicit {
if params.explicit && !params.choice {
expectedClass := ClassContextSpecific
if params.application {
expectedClass = ClassApplication
@ -968,19 +968,13 @@ func parseField(v reflect.Value, bytes []byte, initOffset int, params fieldParam
}
innerOffset := 0
if params.choice {
if !params.explicit {
innerBytes = bytes[initOffset:]
}
}
for i := 0; i < structType.NumField(); i++ {
field := structType.Field(i)
if params.choice {
tag := parseFieldParameters(field.Tag.Get("asn1")).tag
if tag != nil && t.tag == *tag || t.class != ClassContextSpecific && tag == nil {
if tag == nil || params.set {
innerBytes = bytes[initOffset:offset]
}
innerOffset, err = parseField(val.Field(i), innerBytes, innerOffset, fieldParameters{})
return
}
continue
}
if i == 0 && field.Type == rawContentsType {
continue
}

6
asn1/marshal.go
View File

@ -482,9 +482,6 @@ func makeBody(value reflect.Value, params fieldParameters) (e encoder, err error
m := make([]encoder, n1)
for i := 0; i < n1; i++ {
fp := parseFieldParameters(t.Field(i + startingField).Tag.Get("asn1"))
if params.explicit && params.choice {
fp.explicit = true
}
m[i], err = makeField(v.Field(i+startingField), fp)
if err != nil {
return nil, err
@ -501,9 +498,6 @@ func makeBody(value reflect.Value, params fieldParameters) (e encoder, err error
var fp fieldParameters
fp.choice = params.choice
if params.choice && params.set {
fp.explicit = true
}
switch l := v.Len(); l {
case 0:

12
cms/cms.go
View File

@ -65,7 +65,11 @@ func (cms *CMS) Encrypt(data []byte, recipients []*x509.Certificate) (der []byte
var reciInfos []protocol.RecipientInfo
for _, recipient := range recipients {
rInfo := protocol.NewRecipientInfo(recipient, key)
var rInfo protocol.RecipientInfo
rInfo, err = protocol.NewRecipientInfo(recipient, key)
if err != nil {
return
}
reciInfos = append(reciInfos, rInfo)
}
@ -90,7 +94,11 @@ func (cms *CMS) AuthEncrypt(data []byte, recipients []*x509.Certificate) (der []
var reciInfos []protocol.RecipientInfo
for _, recipient := range recipients {
rInfo := protocol.NewRecipientInfo(recipient, key)
var rInfo protocol.RecipientInfo
rInfo, err = protocol.NewRecipientInfo(recipient, key)
if err != nil {
return
}
reciInfos = append(reciInfos, rInfo)
}

85
cms/cms_test.go
View File

@ -3,10 +3,13 @@ package cms
import (
"bytes"
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"log"
"strings"
"testing"
openssl "github.com/InfiniteLoopSpace/go_S-MIME/openssl"
@ -26,62 +29,103 @@ var (
CommonName: "leaf.example.com",
}))
ecKey, _ = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
leafECC = intermediate.Issue(pki.Subject(pkix.Name{
CommonName: "leaf.example.com",
}), pki.PrivateKey(ecKey))
keyPair = tls.Certificate{
Certificate: [][]byte{leaf.Certificate.Raw, intermediate.Certificate.Raw, root.Certificate.Raw},
PrivateKey: leaf.PrivateKey.(crypto.PrivateKey),
Leaf: leaf.Certificate,
}
keyPairECC = tls.Certificate{
Certificate: [][]byte{leafECC.Certificate.Raw, intermediate.Certificate.Raw, root.Certificate.Raw},
PrivateKey: leafECC.PrivateKey.(crypto.PrivateKey),
Leaf: leafECC.Certificate,
}
keyPairs = []tls.Certificate{}
keyPairsOpenssl = []tls.Certificate{}
)
func TestMain(m *testing.M) {
keyPairs = []tls.Certificate{keyPair, keyPairECC}
version, err := openssl.Openssl(nil, "version")
if err == nil {
keyPairsOpenssl = append(keyPairsOpenssl, keyPair)
}
if strings.HasPrefix(string(version), "OpenSSL 1.1") {
openssl.SMIME = "cms"
keyPairsOpenssl = append(keyPairsOpenssl, keyPairECC)
}
m.Run()
}
func TestAuthEnrypt(t *testing.T) {
cms, err := New(keyPair)
for _, keypair := range keyPairs {
cms, err := New(keypair)
if err != nil {
t.Error(err)
}
plaintext := []byte("Hallo Welt!")
ciphertext, err := cms.AuthEncrypt(plaintext, []*x509.Certificate{leaf.Certificate})
ciphertext, err := cms.AuthEncrypt(plaintext, []*x509.Certificate{keypair.Leaf})
if err != nil {
t.Error(err)
}
plain, err := cms.AuthDecrypt(ciphertext)
if err != nil {
log.Fatal(err)
t.Error(err)
}
if !bytes.Equal(plaintext, plain) {
t.Fatal("Encryption and decryption are not inverse")
}
}
}
func TestEnryptDecrypt(t *testing.T) {
cms, err := New(keyPair)
for _, keypair := range keyPairs {
cms, err := New(keypair)
if err != nil {
t.Error(err)
}
plaintext := []byte("Hallo Welt!")
ciphertext, err := cms.Encrypt(plaintext, []*x509.Certificate{leaf.Certificate})
ciphertext, err := cms.Encrypt(plaintext, []*x509.Certificate{keypair.Leaf})
if err != nil {
t.Error(err)
}
plain, err := cms.Decrypt(ciphertext)
if err != nil {
log.Fatal(err)
t.Error(err)
}
if !bytes.Equal(plaintext, plain) {
t.Fatal("Encryption and decryption are not inverse")
}
}
}
func TestSignVerify(t *testing.T) {
cms, err := New(keyPair)
for _, keypair := range keyPairs {
cms, err := New(keypair)
if err != nil {
t.Error(err)
}
@ -99,17 +143,20 @@ func TestSignVerify(t *testing.T) {
if err != nil {
t.Error(err)
}
}
}
func TestEncryptOpenSSL(t *testing.T) {
for _, keypair := range keyPairsOpenssl {
message := []byte("Hallo Welt!")
der, err := openssl.Encrypt(message, leaf.Certificate, "-outform", "DER")
der, err := openssl.Encrypt(message, keypair.Leaf, "-outform", "DER")
if err != nil {
t.Error(err)
}
cms, err := New(keyPair)
cms, err := New(keypair)
plain, err := cms.Decrypt(der)
if err != nil {
t.Error(err)
@ -118,18 +165,21 @@ func TestEncryptOpenSSL(t *testing.T) {
if !bytes.Equal(message, plain) {
t.Fatal("Encryption and decryption are not inverse")
}
}
}
func TestDecryptOpenSSL(t *testing.T) {
for _, keypair := range keyPairsOpenssl {
message := []byte("Hallo Welt!")
cms, _ := New()
ciphertext, err := cms.Encrypt(message, []*x509.Certificate{leaf.Certificate})
ciphertext, err := cms.Encrypt(message, []*x509.Certificate{keypair.Leaf})
if err != nil {
t.Error(err)
}
plain, err := openssl.Decrypt(ciphertext, leaf.PrivateKey, "-inform", "DER")
plain, err := openssl.Decrypt(ciphertext, keypair.PrivateKey, "-inform", "DER")
if err != nil {
t.Error(err)
}
@ -137,12 +187,15 @@ func TestDecryptOpenSSL(t *testing.T) {
if !bytes.Equal(message, plain) {
t.Fatal("Encryption and decryption are not inverse")
}
}
}
func TestSignOpenSSL(t *testing.T) {
for _, keypair := range keyPairsOpenssl {
message := []byte("Hallo Welt")
sig, err := openssl.SignDetached(message, leaf.Certificate, leaf.PrivateKey, []*x509.Certificate{intermediate.Certificate}, "-outform", "DER")
sig, err := openssl.SignDetached(message, keypair.Leaf, keypair.PrivateKey, []*x509.Certificate{intermediate.Certificate}, "-outform", "DER")
if err != nil {
t.Error(err)
}
@ -157,10 +210,13 @@ func TestSignOpenSSL(t *testing.T) {
if err != nil {
t.Error(err)
}
}
}
func TestVerifyOpenSSL(t *testing.T) {
cms, err := New(keyPair)
for _, keypair := range keyPairsOpenssl {
cms, err := New(keypair)
if err != nil {
t.Error(err)
}
@ -184,4 +240,5 @@ func TestVerifyOpenSSL(t *testing.T) {
if !bytes.Equal(msg, sig) {
t.Fatal("Signed message and message do not agree!")
}
}
}

218
cms/protocol/ecdh.go Normal file
View File

@ -0,0 +1,218 @@
package protocol
import (
"crypto"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"encoding/asn1"
"encoding/binary"
"errors"
"math/big"
"github.com/InfiniteLoopSpace/go_S-MIME/oid"
)
var errUnsupported = errors.New("Unsupported hash function")
// ECDHsharedSecret computes shared secret with ephemeral static ECDH
func ECDHsharedSecret(curve elliptic.Curve, priv []byte, pubX, pubY *big.Int) []byte {
x, _ := curve.ScalarMult(pubX, pubY, priv)
return x.Bytes()
}
// ANSIx963KDF implents ANSI X9.63 key derivation function
func ANSIx963KDF(sharedSecret, sharedInfo []byte, keyLen int, hash crypto.Hash) (key []byte, err error) {
ctr := make([]byte, 4)
ctr[3] = 0x01
if hash == 0 || !hash.Available() {
return nil, errUnsupported
}
h := hash.New()
for i := 0; i < keyLen/hash.Size()+1; i++ {
h.Reset()
h.Write(sharedSecret)
h.Write(ctr)
h.Write(sharedInfo)
key = append(key, h.Sum(nil)...)
// Increment counter
for i := len(ctr) - 1; i >= 0; i-- {
ctr[i]++
if ctr[i] != 0 {
break
}
}
}
return key[:keyLen], nil
}
func encryptKeyECDH(key []byte, recipient *x509.Certificate) (kari KeyAgreeRecipientInfo, err error) {
keyWrapAlgorithm := oid.KeyWrap{KeyWrapAlgorithm: oid.AES128Wrap}
keyEncryptionAlgorithm := oid.DHSinglePassstdDHsha256kdfscheme
hash := oid.KDFHashAlgorithm[keyEncryptionAlgorithm.String()]
kari.UKM = make([]byte, 8)
rand.Read(kari.UKM)
kari.Version = 3
kari.Originator.OriginatorKey.Algorithm = pkix.AlgorithmIdentifier{Algorithm: oid.ECPublicKey}
// check recipient key
if recipient.PublicKeyAlgorithm != x509.ECDSA {
err = errors.New("Recipient certficiate has wrong public key algorithm, expected ECDSA")
return
}
pubKey, ok := recipient.PublicKey.(*ecdsa.PublicKey)
if !ok {
err = errors.New("Can not parse public key of recipient")
return
}
// genrate ephemeral public key and key encryption key
priv, x, y, err := elliptic.GenerateKey(pubKey.Curve, rand.Reader)
if err != nil {
return
}
ephPubKey := elliptic.Marshal(pubKey.Curve, x, y)
kari.Originator.OriginatorKey.PublicKey = asn1.BitString{Bytes: ephPubKey, BitLength: len(ephPubKey) * 8}
sharedSecret := ECDHsharedSecret(pubKey.Curve, priv, pubKey.X, pubKey.Y)
keyLenBigEnd := make([]byte, 4)
binary.BigEndian.PutUint32(keyLenBigEnd, uint32(keyWrapAlgorithm.KeyLen())*8)
sharedInfo := ECCCMSSharedInfo{KeyInfo: keyWrapAlgorithm.AlgorithmIdentifier(),
SuppPubInfo: keyLenBigEnd,
EntityUInfo: kari.UKM}
sharedInfoDER, err := asn1.Marshal(sharedInfo)
kek, err := ANSIx963KDF(sharedSecret, sharedInfoDER, keyWrapAlgorithm.KeyLen(), hash)
if err != nil {
return
}
// encrypt key
keyWrapAlgorithm.KEK = kek
encKey, err := keyWrapAlgorithm.Wrap(key)
if err != nil {
return
}
keyWrapAlgorithmIdentifier, err := RawValue(keyWrapAlgorithm.AlgorithmIdentifier())
if err != nil {
return
}
kari.KeyEncryptionAlgorithm = pkix.AlgorithmIdentifier{Algorithm: keyEncryptionAlgorithm,
Parameters: keyWrapAlgorithmIdentifier}
ias, err := NewIssuerAndSerialNumber(recipient)
karID := KeyAgreeRecipientIdentifier{IAS: ias}
kari.RecipientEncryptedKeys = append(kari.RecipientEncryptedKeys, RecipientEncryptedKey{RID: karID, EncryptedKey: encKey})
return
}
// ECCCMSSharedInfo ECC-CMS-SharedInfo ::= SEQUENCE {
// keyInfo AlgorithmIdentifier,
// entityUInfo [0] EXPLICIT OCTET STRING OPTIONAL,
// suppPubInfo [2] EXPLICIT OCTET STRING }
type ECCCMSSharedInfo struct {
KeyInfo pkix.AlgorithmIdentifier
EntityUInfo []byte `asn1:"optional,explicit,tag:0"`
SuppPubInfo []byte `asn1:"explicit,tag:2"`
}
func (kari *KeyAgreeRecipientInfo) decryptKey(keyPair tls.Certificate) (key []byte, err error) {
// check for ec key
if kari.Version != 3 {
err = errors.New("Version not supported")
return
}
if !kari.Originator.OriginatorKey.Algorithm.Algorithm.Equal(oid.ECPublicKey) {
err = errors.New("Orginator key algorithm not supported")
return
}
pubKey, ok := keyPair.Leaf.PublicKey.(*ecdsa.PublicKey)
if !ok {
err = errors.New("Can not parse public key of recipient")
return
}
x, y := elliptic.Unmarshal(pubKey.Curve, kari.Originator.OriginatorKey.PublicKey.Bytes)
// genrate ephemeral public key and key encryption key
priv := keyPair.PrivateKey.(*ecdsa.PrivateKey)
privateKeyBytes := keyPair.PrivateKey.(*ecdsa.PrivateKey).D.Bytes()
paddedPrivateKey := make([]byte, (priv.Curve.Params().N.BitLen()+7)/8)
copy(paddedPrivateKey[len(paddedPrivateKey)-len(privateKeyBytes):], privateKeyBytes)
sharedSecret := ECDHsharedSecret(pubKey.Curve, paddedPrivateKey, x, y)
hash, ok := oid.KDFHashAlgorithm[kari.KeyEncryptionAlgorithm.Algorithm.String()]
if !ok {
err = errors.New("Unsupported key derivation hash algorithm")
return
}
var keyWrapAlgorithmIdentifier pkix.AlgorithmIdentifier
asn1.Unmarshal(kari.KeyEncryptionAlgorithm.Parameters.FullBytes, &keyWrapAlgorithmIdentifier)
keyWrapAlgorithm := oid.KeyWrap{KeyWrapAlgorithm: keyWrapAlgorithmIdentifier.Algorithm}
//
keyLenBigEnd := make([]byte, 4)
binary.BigEndian.PutUint32(keyLenBigEnd, uint32(keyWrapAlgorithm.KeyLen())*8)
sharedInfo := ECCCMSSharedInfo{KeyInfo: keyWrapAlgorithmIdentifier,
SuppPubInfo: keyLenBigEnd,
EntityUInfo: kari.UKM}
sharedInfoDER, err := asn1.Marshal(sharedInfo)
kek, err := ANSIx963KDF(sharedSecret, sharedInfoDER, keyWrapAlgorithm.KeyLen(), hash)
if err != nil {
return
}
keyWrapAlgorithm.KEK = kek
// encrypt key
ias, err := NewIssuerAndSerialNumber(keyPair.Leaf)
if err != nil {
return
}
for i := range kari.RecipientEncryptedKeys {
if kari.RecipientEncryptedKeys[i].RID.IAS.Equal(ias) {
key, err = keyWrapAlgorithm.UnWrap(kari.RecipientEncryptedKeys[i].EncryptedKey)
return
}
}
err = ErrNoKeyFound
return
}

2
cms/protocol/envelopeddata.go
View File

@ -58,7 +58,7 @@ func (ed *EnvelopedData) decryptKey(keyPair tls.Certificate) (key []byte, err er
for i := range ed.RecipientInfos {
key, err = ed.RecipientInfos[i].decryptKey(keyPair)
if key != nil {
if key != nil || err != ErrNoKeyFound {
return
}
}

41
cms/protocol/reciepientinfo.go
View File

@ -33,8 +33,14 @@ type RecipientInfo struct {
func (recInfo *RecipientInfo) decryptKey(keyPair tls.Certificate) (key []byte, err error) {
return recInfo.KTRI.decryptKey(keyPair)
key, err = recInfo.KTRI.decryptKey(keyPair)
if key != nil {
return
}
key, err = recInfo.KARI.decryptKey(keyPair)
return
}
//KeyTransRecipientInfo ::= SEQUENCE {
@ -102,7 +108,7 @@ type RecipientIdentifier struct {
}
// NewRecipientInfo creates RecipientInfo for giben recipient and key.
func NewRecipientInfo(recipient *x509.Certificate, key []byte) RecipientInfo {
func NewRecipientInfo(recipient *x509.Certificate, key []byte) (info RecipientInfo, err error) {
version := 0 //issuerAndSerialNumber
rid := RecipientIdentifier{}
@ -118,24 +124,35 @@ func NewRecipientInfo(recipient *x509.Certificate, key []byte) RecipientInfo {
rid.SKI = recipient.SubjectKeyId
}
kea := oid.PublicKeyAlgorithmToEncrytionAlgorithm[recipient.PublicKeyAlgorithm]
if _, ok := oid.PublicKeyAlgorithmToEncrytionAlgorithm[recipient.PublicKeyAlgorithm]; !ok {
log.Fatal("NewRecipientInfo: PublicKeyAlgorithm not supported")
switch recipient.PublicKeyAlgorithm {
case x509.RSA:
var encrypted []byte
encrypted, err = encryptKeyRSA(key, recipient)
if err != nil {
return
}
encrypted, _ := encryptKey(key, recipient)
info := RecipientInfo{
info = RecipientInfo{
KTRI: KeyTransRecipientInfo{
Version: version,
Rid: rid,
KeyEncryptionAlgorithm: kea,
KeyEncryptionAlgorithm: pkix.AlgorithmIdentifier{Algorithm: oid.EncryptionAlgorithmRSA},
EncryptedKey: encrypted,
}}
return info
case x509.ECDSA:
var kari KeyAgreeRecipientInfo
kari, err = encryptKeyECDH(key, recipient)
if err != nil {
return
}
info = RecipientInfo{KARI: kari}
default:
err = errors.New("Public key algorithm not supported")
}
return
}
func encryptKey(key []byte, recipient *x509.Certificate) ([]byte, error) {
func encryptKeyRSA(key []byte, recipient *x509.Certificate) ([]byte, error) {
if pub := recipient.PublicKey.(*rsa.PublicKey); pub != nil {
return rsa.EncryptPKCS1v15(rand.Reader, pub, key)
}

8
cms/protocol/signeddata.go
View File

@ -379,8 +379,12 @@ func (sd *SignedData) Verify(Opts x509.VerifyOptions, detached []byte) (chains [
return
}
}
err = cert.CheckSignature(signer.X509SignatureAlgorithm(), signedMessage, signer.Signature)
var sigAlg x509.SignatureAlgorithm
sigAlg, err = signer.X509SignatureAlgorithm()
if err != nil {
return
}
err = cert.CheckSignature(sigAlg, signedMessage, signer.Signature)
if err != nil {
return
}

10
cms/protocol/signerinfo.go
View File

@ -6,6 +6,7 @@ import (
"crypto/x509"
"crypto/x509/pkix"
"encoding/asn1"
"fmt"
"time"
asn "github.com/InfiniteLoopSpace/go_S-MIME/asn1"
@ -83,13 +84,18 @@ func (si SignerInfo) Hash() (crypto.Hash, error) {
// X509SignatureAlgorithm gets the x509.SignatureAlgorithm that should be used
// for verifying this SignerInfo's signature.
func (si SignerInfo) X509SignatureAlgorithm() x509.SignatureAlgorithm {
func (si SignerInfo) X509SignatureAlgorithm() (sigAlg x509.SignatureAlgorithm, err error) {
var (
sigOID = si.SignatureAlgorithm.Algorithm.String()
digestOID = si.DigestAlgorithm.Algorithm.String()
)
sigAlg, ok := oid.SignatureAlgorithms[sigOID][digestOID]
return oid.SignatureAlgorithms[sigOID][digestOID]
if !ok {
err = fmt.Errorf("Signature algorithm with OID %s in combination with digest with OID %s not supported", sigOID, digestOID)
}
return
}
// GetContentTypeAttribute gets the signed ContentType attribute from the

163
oid/key_wrap.go Normal file
View File

@ -0,0 +1,163 @@
package oid
import (
"crypto/aes"
"crypto/cipher"
"crypto/subtle"
"crypto/x509/pkix"
"encoding/asn1"
"encoding/binary"
"errors"
)
// KeyWrap wraps and unwraps key with the key encrytion key (KEK) for a given (KeyWrapAlgorithm)
type KeyWrap struct {
KEK []byte
KeyWrapAlgorithm asn1.ObjectIdentifier
}
// Wrap wraps the content encryption key (cek)
func (kw *KeyWrap) Wrap(cek []byte) (ciphertext []byte, err error) {
var block cipher.Block
switch kw.KeyWrapAlgorithm.String() {
case AES128Wrap.String(), AES192Wrap.String(), AES256Wrap.String():
block, err = aes.NewCipher(kw.KEK)
if err != nil {
return
}
}
return Wrap(block, cek)
}
// UnWrap unwraps the encrypted key (encKey)
func (kw *KeyWrap) UnWrap(encKey []byte) (cek []byte, err error) {
var block cipher.Block
switch kw.KeyWrapAlgorithm.String() {
case AES128Wrap.String(), AES192Wrap.String(), AES256Wrap.String():
block, err = aes.NewCipher(kw.KEK)
if err != nil {
return
}
}
return Unwrap(block, encKey)
}
// KeyLen returns the key lenght of the key wrap algorithm
func (kw *KeyWrap) KeyLen() (len int) {
switch kw.KeyWrapAlgorithm.String() {
case AES128Wrap.String():
len = 16
case AES192Wrap.String():
len = 24
case AES256Wrap.String():
len = 32
}
return
}
// AlgorithmIdentifier returns the OID of the key wrap algorithm
func (kw *KeyWrap) AlgorithmIdentifier() (algID pkix.AlgorithmIdentifier) {
switch kw.KeyWrapAlgorithm.String() {
case AES128Wrap.String(), AES192Wrap.String(), AES256Wrap.String():
algID = pkix.AlgorithmIdentifier{Algorithm: kw.KeyWrapAlgorithm}
}
return
}
// defaultIV from RFC-3394
var defaultIV = []byte{0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6}
// Wrap encrypts the content encryption key (cek) with the given AES cipher (block), using the AES Key Wrap algorithm (RFC-3394)
func Wrap(block cipher.Block, cek []byte) (encKey []byte, err error) {
if len(cek)%8 != 0 {
return nil, errors.New("Lenght of cek must be in 8-byte blocks")
}
// 1. Initialize variables
// Set A = IV, an initial value (see 2.2.3)
B := make([]byte, 16)
copy(B, defaultIV)
// For i = 1 to n
// R[i] = P[i]
encKey = make([]byte, len(cek)+8)
copy(encKey[8:], cek)
n := len(cek) / 8
// 2. Calculate intermediate values.
for j := 0; j <= 5; j++ {
for i := 1; i <= n; i++ {
// B = AES(K, A | R[i])
copy(B[8:], encKey[i*8:(i+1)*8])
block.Encrypt(B, B)
// A = MSB(64, B) ^ t where t = (n*j)+i
t := uint64(n*j + i)
b := binary.BigEndian.Uint64(B[:8]) ^ t
binary.BigEndian.PutUint64(B[:8], b)
// R[i] = LSB(64, B)
copy(encKey[i*8:(i+1)*8], B[8:])
}
}
// 3. Output the results.
copy(encKey[:8], B[:8])
return
}
// Unwrap decrypts the provided encrypted key (encKey) with the given AES cipher (block), using the AES Key Wrap algorithm (RFC-3394).
// Returns an error if validation fails.
func Unwrap(block cipher.Block, encKey []byte) (cek []byte, err error) {
if len(cek)%8 != 0 {
return nil, errors.New("Length of encKey must multiple 8-bytes")
}
//Initialize variables
B := make([]byte, 16)
copy(B, encKey[:8])
cek = make([]byte, len(encKey)-8)
copy(cek, encKey[8:])
n := (len(encKey) / 8) - 1
//Compute intermediate values
for j := 5; j >= 0; j-- {
for i := n; i >= 1; i-- {
// B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i
copy(B[8:], cek[(i-1)*8:i*8])
t := uint64(n*j + i)
b := binary.BigEndian.Uint64(B[:8]) ^ t
binary.BigEndian.PutUint64(B[:8], b)
block.Decrypt(B, B)
// A = MSB(64, B)
// R[i] = LSB(64, B)
copy(cek[(i-1)*8:i*8], B[8:])
}
}
if subtle.ConstantTimeCompare(B[:8], defaultIV) != 1 {
return nil, errors.New("Integrity check failed - unexpected IV")
}
//Output
return
}

47
oid/oid.go
View File

@ -30,6 +30,11 @@ var (
var (
SignatureAlgorithmRSA = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
SignatureAlgorithmECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
SignatureAlgorithmECDSAwithSHA1 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 1}
SignatureAlgorithmECDSAwithSHA224 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 1}
SignatureAlgorithmECDSAwithSHA256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 2}
SignatureAlgorithmECDSAwithSHA384 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 3}
SignatureAlgorithmECDSAwithSHA512 = asn1.ObjectIdentifier{1, 2, 840, 10045, 4, 3, 4}
)
// Public Key Encryption OIDs
@ -51,6 +56,27 @@ var (
SubjectKeyIdentifier = asn1.ObjectIdentifier{2, 5, 29, 14}
)
// Elliptic curve public key OID
var (
ECPublicKey = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
)
// DH Key Derivation Schemes OIDs
var (
DHSinglePassstdDHsha1kdfscheme = asn1.ObjectIdentifier{1, 3, 133, 16, 840, 63, 0, 2}
DHSinglePassstdDHsha224kdfscheme = asn1.ObjectIdentifier{1, 3, 132, 1, 11, 0}
DHSinglePassstdDHsha256kdfscheme = asn1.ObjectIdentifier{1, 3, 132, 1, 11, 1}
DHSinglePassstdDHsha384kdfscheme = asn1.ObjectIdentifier{1, 3, 132, 1, 11, 2}
DHSinglePassstdDHsha512kdfscheme = asn1.ObjectIdentifier{1, 3, 132, 1, 11, 3}
)
// Key wrap algorithm OIDs
var (
AES128Wrap = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 1, 5}
AES192Wrap = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 1, 25}
AES256Wrap = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 1, 45}
)
// DigestAlgorithmToHash maps digest OIDs to crypto.Hash values.
var DigestAlgorithmToHash = map[string]crypto.Hash{
DigestAlgorithmSHA1.String(): crypto.SHA1,
@ -113,6 +139,18 @@ var SignatureAlgorithms = map[string]map[string]x509.SignatureAlgorithm{
DigestAlgorithmSHA384.String(): x509.ECDSAWithSHA384,
DigestAlgorithmSHA512.String(): x509.ECDSAWithSHA512,
},
SignatureAlgorithmECDSAwithSHA1.String(): map[string]x509.SignatureAlgorithm{
DigestAlgorithmSHA1.String(): x509.ECDSAWithSHA1,
},
SignatureAlgorithmECDSAwithSHA256.String(): map[string]x509.SignatureAlgorithm{
DigestAlgorithmSHA256.String(): x509.ECDSAWithSHA256,
},
SignatureAlgorithmECDSAwithSHA384.String(): map[string]x509.SignatureAlgorithm{
DigestAlgorithmSHA384.String(): x509.ECDSAWithSHA384,
},
SignatureAlgorithmECDSAwithSHA512.String(): map[string]x509.SignatureAlgorithm{
DigestAlgorithmSHA512.String(): x509.ECDSAWithSHA512,
},
}
// PublicKeyAlgorithmToSignatureAlgorithm maps certificate public key
@ -127,3 +165,12 @@ var PublicKeyAlgorithmToSignatureAlgorithm = map[x509.PublicKeyAlgorithm]pkix.Al
var PublicKeyAlgorithmToEncrytionAlgorithm = map[x509.PublicKeyAlgorithm]pkix.AlgorithmIdentifier{
x509.RSA: pkix.AlgorithmIdentifier{Algorithm: EncryptionAlgorithmRSA},
}
// KDFHashAlgorithm key derivation schemes to its hash algorithms
var KDFHashAlgorithm = map[string]crypto.Hash{
DHSinglePassstdDHsha1kdfscheme.String(): crypto.SHA1,
DHSinglePassstdDHsha224kdfscheme.String(): crypto.SHA224,
DHSinglePassstdDHsha256kdfscheme.String(): crypto.SHA256,
DHSinglePassstdDHsha384kdfscheme.String(): crypto.SHA384,
DHSinglePassstdDHsha512kdfscheme.String(): crypto.SHA512,
}

16
oid/symmetric_ciphers.go
View File

@ -32,9 +32,10 @@ var (
AEADChaCha20Poly1305 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 16, 3, 18}
)
var symmetricKeyLen = map[string]int{
EncryptionAlgorithmDESCBC.String(): 7,
EncryptionAlgorithmDESEDE3CBC.String(): 21,
// SymmetricKeyLen maps the encryption algorithm to its key length
var SymmetricKeyLen = map[string]int{
EncryptionAlgorithmDESCBC.String(): 8,
EncryptionAlgorithmDESEDE3CBC.String(): 24,
EncryptionAlgorithmAES128CBC.String(): 16,
EncryptionAlgorithmAES256CBC.String(): 32,
//AEAD
@ -46,7 +47,7 @@ var symmetricKeyLen = map[string]int{
func (e *EncryptionAlgorithm) Encrypt(plaintext []byte) (ciphertext []byte, err error) {
if e.Key == nil {
e.Key = make([]byte, symmetricKeyLen[e.EncryptionAlgorithmIdentifier.String()])
e.Key = make([]byte, SymmetricKeyLen[e.EncryptionAlgorithmIdentifier.String()])
rand.Read(e.Key)
}
@ -71,7 +72,7 @@ func (e *EncryptionAlgorithm) Encrypt(plaintext []byte) (ciphertext []byte, err
switch e.EncryptionAlgorithmIdentifier.String() {
case EncryptionAlgorithmAES128CBC.String(), EncryptionAlgorithmAES256CBC.String():
if e.IV == nil {
e.IV = make([]byte, len(e.Key))
e.IV = make([]byte, blockCipher.BlockSize())
rand.Read(e.IV)
}
@ -180,7 +181,6 @@ func (e *EncryptionAlgorithm) Decrypt(ciphertext []byte) (plaintext []byte, err
switch e.EncryptionAlgorithmIdentifier.String() {
case EncryptionAlgorithmAES128CBC.String(), EncryptionAlgorithmAES256CBC.String(), EncryptionAlgorithmDESCBC.String(), EncryptionAlgorithmDESEDE3CBC.String():
e.IV = e.ContentEncryptionAlgorithmIdentifier.Parameters.Bytes
blockMode = cipher.NewCBCDecrypter(blockCipher, e.IV)
case EncryptionAlgorithmAES128GCM.String():
aead, err = cipher.NewGCM(blockCipher)
@ -198,7 +198,6 @@ func (e *EncryptionAlgorithm) Decrypt(ciphertext []byte) (plaintext []byte, err
case EncryptionAlgorithmAES128CBC.String(), EncryptionAlgorithmAES256CBC.String(), EncryptionAlgorithmDESCBC.String(), EncryptionAlgorithmDESEDE3CBC.String():
plaintext = make([]byte, len(ciphertext))
blockMode.CryptBlocks(plaintext, ciphertext)
return unpad(plaintext, blockMode.BlockSize())
case EncryptionAlgorithmAES128GCM.String(), AEADChaCha20Poly1305.String():
var cipher []byte
@ -247,6 +246,9 @@ func unpad(data []byte, blocklen int) ([]byte, error) {
// the last byte is the length of padding
padlen := int(data[len(data)-1])
if padlen > blocklen {
return nil, fmt.Errorf("pad len %d is bigger than block len len %d", padlen, blocklen)
}
// check padding integrity, all bytes should be the same
pad := data[len(data)-padlen:]

60
openssl/openssl.go
View File

@ -4,26 +4,29 @@ package openssl
import (
"bytes"
"crypto"
"crypto/rsa"
"crypto/x509"
"encoding/pem"
"fmt"
"io/ioutil"
"os"
"os/exec"
"strings"
)
// SMIME is the commpand used for openssl smime, can be replaces with cms
var SMIME = "smime"
//Encrypt a message with openssl
func Encrypt(in []byte, cert *x509.Certificate, opts ...string) (der []byte, err error) {
tmp, err := ioutil.TempFile("", "example")
defer os.Remove(tmp.Name())
tmpKey, err := ioutil.TempFile("", "example")
defer os.Remove(tmpKey.Name())
pem.Encode(tmp, &pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw})
pem.Encode(tmpKey, &pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw})
param := []string{"smime", "-encrypt", "-aes128"}
param := []string{SMIME, "-encrypt", "-aes128"}
param = append(param, opts...)
param = append(param, tmp.Name())
param = append(param, tmpKey.Name())
der, err = openssl(in, param...)
return
@ -32,20 +35,24 @@ func Encrypt(in []byte, cert *x509.Certificate, opts ...string) (der []byte, err
//Decrypt a message with openssl
func Decrypt(in []byte, key crypto.PrivateKey, opts ...string) (plain []byte, err error) {
tmp, err := ioutil.TempFile("", "example")
defer os.Remove(tmp.Name())
tmpKey, err := ioutil.TempFile("", "example")
defer os.Remove(tmpKey.Name())
pem.Encode(tmp, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key.(*rsa.PrivateKey))})
keyDER, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return
}
pem.Encode(tmpKey, &pem.Block{Type: "PRIVATE KEY", Bytes: keyDER})
param := []string{"smime", "-decrypt"}
param := []string{SMIME, "-decrypt"}
param = append(param, opts...)
param = append(param, []string{"-decrypt", "-inkey", tmp.Name()}...)
param = append(param, []string{"-inkey", tmpKey.Name()}...)
plain, err = openssl(in, param...)
return
}
//Create a detached signature with openssl
// SignDetached creates a detached signature with openssl
func SignDetached(in []byte, cert *x509.Certificate, key crypto.PrivateKey, interm []*x509.Certificate, opts ...string) (plain []byte, err error) {
tmpCert, err := ioutil.TempFile("", "example")
@ -56,7 +63,11 @@ func SignDetached(in []byte, cert *x509.Certificate, key crypto.PrivateKey, inte
tmpKey, err := ioutil.TempFile("", "example")
defer os.Remove(tmpKey.Name())
pem.Encode(tmpKey, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key.(*rsa.PrivateKey))})
keyDER, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return
}
pem.Encode(tmpKey, &pem.Block{Type: "PRIVATE KEY", Bytes: keyDER})
tmpInterm, err := ioutil.TempFile("", "example")
defer os.Remove(tmpInterm.Name())
@ -65,7 +76,7 @@ func SignDetached(in []byte, cert *x509.Certificate, key crypto.PrivateKey, inte
pem.Encode(tmpInterm, &pem.Block{Type: "CERTIFICATE", Bytes: i.Raw})
}
param := []string{"smime", "-sign", "-nodetach"}
param := []string{SMIME, "-sign", "-nodetach"}
param = append(param, opts...)
param = append(param, []string{"-signer", tmpCert.Name(), "-inkey", tmpKey.Name(), "-certfile", tmpInterm.Name()}...)
plain, err = openssl(in, param...)
@ -73,7 +84,7 @@ func SignDetached(in []byte, cert *x509.Certificate, key crypto.PrivateKey, inte
return
}
//Create a signature with openssl
// Sign creates a signature with openssl
func Sign(in []byte, cert *x509.Certificate, key crypto.PrivateKey, interm []*x509.Certificate, opts ...string) (plain []byte, err error) {
tmpCert, err := ioutil.TempFile("", "example")
@ -84,7 +95,11 @@ func Sign(in []byte, cert *x509.Certificate, key crypto.PrivateKey, interm []*x5
tmpKey, err := ioutil.TempFile("", "example")
defer os.Remove(tmpKey.Name())
pem.Encode(tmpKey, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key.(*rsa.PrivateKey))})
keyDER, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return
}
pem.Encode(tmpKey, &pem.Block{Type: "PRIVATE KEY", Bytes: keyDER})
tmpInterm, err := ioutil.TempFile("", "example")
defer os.Remove(tmpInterm.Name())
@ -93,7 +108,7 @@ func Sign(in []byte, cert *x509.Certificate, key crypto.PrivateKey, interm []*x5
pem.Encode(tmpInterm, &pem.Block{Type: "CERTIFICATE", Bytes: i.Raw})
}
param := []string{"smime", "-sign"}
param := []string{SMIME, "-sign"}
param = append(param, opts...)
param = append(param, []string{"-signer", tmpCert.Name(), "-inkey", tmpKey.Name(), "-certfile", tmpInterm.Name()}...)
plain, err = openssl(in, param...)
@ -109,7 +124,7 @@ func Verify(in []byte, ca *x509.Certificate, opts ...string) (plain []byte, err
pem.Encode(tmpCA, &pem.Block{Type: "CERTIFICATE", Bytes: ca.Raw})
param := []string{"smime", "-verify"}
param := []string{SMIME, "-verify"}
param = append(param, opts...)
param = append(param, []string{"-CAfile", tmpCA.Name()}...)
plain, err = openssl(in, param...)
@ -117,6 +132,11 @@ func Verify(in []byte, ca *x509.Certificate, opts ...string) (plain []byte, err
return
}
// Openssl runs the openssl command with given args
func Openssl(stdin []byte, args ...string) ([]byte, error) {
return openssl(stdin, args...)
}
func openssl(stdin []byte, args ...string) ([]byte, error) {
cmd := exec.Command("openssl", args...)
@ -133,5 +153,9 @@ func openssl(stdin []byte, args ...string) ([]byte, error) {
return nil, err
}
if strings.Contains(errs.String(), "Error") {
return nil, fmt.Errorf("error running %s (%s):\n ", cmd.Args, errs.String())
}
return out.Bytes(), nil
}

2
smime/smime_test.go
View File

@ -234,7 +234,7 @@ Y0ZB9qANMAsGA1UdDzEEAwIAEA==
-----END PRIVATE KEY-----`
//https://github.com/fullsailor/pkcs7/issues/9
func TestiTunesReceipt(t *testing.T) {
func TestSampleiTunesReceipt(t *testing.T) {
b, err := base64.StdEncoding.DecodeString(strings.TrimSpace(iTunesReceipt))
if err != nil {