Go语言将Modulus指数转换为X.509证书

Question

我已经看到了很多有关如何将X.509转换为指数模量的示例，但是我没有看到相反的例子。

我从关键端点获得的值如下所示：

{"keys":    [{"alg":"RS256","e":"AQAB","n":"ok6rvXu95337IxsDXrKzlIqw_I_zPDG8JyEw2CTOtNMoDi1QzpXQVMGj2snNEmvNYaCTmFf51I-EDgeFLLexr40jzBXlg72quV4aw4yiNuxkigW0gMA92OmaT2jMRIdDZM8mVokoxyPfLub2YnXHFq0XuUUgkX_TlutVhgGbyPN0M12teYZtMYo2AUzIRggONhHvnibHP0CPWDjCwSfp3On1Recn4DPxbn3DuGslF2myalmCtkujNcrhHLhwYPP-yZFb8e0XSNTcQvXaQxAqmnWH6NXcOtaeWMQe43PNTAyNinhndgI8ozG3Hz-1NzHssDH_yk6UYFSszhDbWAzyqw","kid":"wyMwK4A6CL9Qw11uofVeyQ119XyX-xykymkkXygZ5OM","kty":"RSA","use":"sig"},{"alg":"RS256","e":"AQAB","n":"nXv6FSAcMjuanQ2hIIUb8Vkqe94t98kPh2T8-0j6-Jq8pOclgKdtVeIZcBE9F_XiuJvg4b6WVs-uvA-pS8mmMvQ21xU5Q_37Cojv8v_QlHWETHwEJdXXiY2Xq5LgXDSwEhhdDZHSMQYDuvhp_P6nl2LNqqUvJkjoFWcnn2btgSIUQROIaDdxtx7_2h4oUi5u11BGSF2SZZiEpDAKT08Htv3uwXdwDA6ll99fbi8X8RmH5oY_tIZTeIzu50qHxElPewoYO8QrJYsO9oFcCPMHGxYWjXQEa-QZYgo0wS9zRIkeJc5kshc4-9Uhv2DVIjk_-ofGlML9ieggGyillBKptw","kid":"GRF55Lbzgg4sANCmER-sm55eX_qUOpY8UTptDmDG_6U","kty":"RSA","use":"sig"}]}

我认为这是关键：

ok6rvXu95337IxsDXrKzlIqw_I_zPDG8JyEw2CTOtNMoDi1QzpXQVMGj2snNEmvNYaCTmFf51I-EDgeFLLexr40jzBXlg72quV4aw4yiNuxkigW0gMA92OmaT2jMRIdDZM8mVokoxyPfLub2YnXHFq0XuUUgkX_TlutVhgGbyPN0M12teYZtMYo2AUzIRggONhHvnibHP0CPWDjCwSfp3On1Recn4DPxbn3DuGslF2myalmCtkujNcrhHLhwYPP-yZFb8e0XSNTcQvXaQxAqmnWH6NXcOtaeWMQe43PNTAyNinhndgI8ozG3Hz-1NzHssDH_yk6UYFSszhDbWAzyqw

var key = "ok6rvXu95337IxsDXrKzlIqw_I_zPDG8JyEw2CTOtNMoDi1QzpXQVMGj2snNEmvNYaCTmFf51I-EDgeFLLexr40jzBXlg72quV4aw4yiNuxkigW0gMA92OmaT2jMRIdDZM8mVokoxyPfLub2YnXHFq0XuUUgkX_TlutVhgGbyPN0M12teYZtMYo2AUzIRggONhHvnibHP0CPWDjCwSfp3On1Recn4DPxbn3DuGslF2myalmCtkujNcrhHLhwYPP-yZFb8e0XSNTcQvXaQxAqmnWH6NXcOtaeWMQe43PNTAyNinhndgI8ozG3Hz-1NzHssDH_yk6UYFSszhDbWAzyqw"

如果有人能指出我正确的方向，请使用GO语言。我还将它放在Go Lang游乐场上，以便其他人可以使用它。

Answer 1

您可以将值直接放入rsa.PublicKey，可以按原样使用。由于要将其编码为pem编码的x.509，因此可以使用该x509.MarshalPKIXPublicKey函数封送der块，并使用pem包对其进行编码。

解开示例中的第一个键后jwk：

// decode the base64 bytes for n
nb, err := base64.RawURLEncoding.DecodeString(jwk["n"])
if err != nil {
    log.Fatal(err)
}

e := 65537
// The default exponent is usually 65537, so just compare the
// base64 for [1,0,1] or [0,1,0,1]
if jwk["e"] != "AQAB" && jwk["e"] != "AAEAAQ" {
    // still need to decode the big-endian int
    log.Fatal("need to deocde e:", jwk["e"])
}

pk := &rsa.PublicKey{
    N: new(big.Int).SetBytes(nb),
    E: e,
}

der, err := x509.MarshalPKIXPublicKey(pk)
if err != nil {
    log.Fatal(err)
}

block := &pem.Block{
    Type:  "RSA PUBLIC KEY",
    Bytes: der,
}

var out bytes.Buffer
pem.Encode(&out, block)
fmt.Println(out.String())

将输出：

-----BEGIN RSA PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAok6rvXu95337IxsDXrKz
lIqw/I/zPDG8JyEw2CTOtNMoDi1QzpXQVMGj2snNEmvNYaCTmFf51I+EDgeFLLex
r40jzBXlg72quV4aw4yiNuxkigW0gMA92OmaT2jMRIdDZM8mVokoxyPfLub2YnXH
Fq0XuUUgkX/TlutVhgGbyPN0M12teYZtMYo2AUzIRggONhHvnibHP0CPWDjCwSfp
3On1Recn4DPxbn3DuGslF2myalmCtkujNcrhHLhwYPP+yZFb8e0XSNTcQvXaQxAq
mnWH6NXcOtaeWMQe43PNTAyNinhndgI8ozG3Hz+1NzHssDH/yk6UYFSszhDbWAzy
qwIDAQAB
-----END RSA PUBLIC KEY-----

https://play.golang.org/p/Ch6Nr9F6Ik