我有一个加密的私钥，我知道密码。
我需要使用 Java 库对其进行解密。
不过我不想使用 BouncyCaSTLe，除非别无选择。根据以往的经验，变化太大，文档不够。
私钥是这样的形式:
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,56F3A98D9CFFA77A
X5h7SUDStF1tL16lRM+AfZb1UBDQ0D1YbQ6vmIlXiK....
.....
/KK5CZmIGw==
-----END RSA PRIVATE KEY-----
我相信关键数据是 Base64 编码的，因为我在 64 个字符后看到 \r\n。
我尝试了以下方法来解密 key :
import java.security.Key;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import javax.crypto.EncryptedPrivateKeyInfo;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
public String decrypt(String keyDataStr, String passwordStr){
// This key data start from "X5... to =="
char [] password=passwordStr.toCharArray();
byte [] keyDataBytes=com.sun.jersey.core.util.Base64.decode(keyDataStr);
PBEKeySpec pbeSpec = new PBEKeySpec(password);
EncryptedPrivateKeyInfo pkinfo = new EncryptedPrivateKeyInfo(keyDataBytes);
SecretKeyFactory skf = SecretKeyFactory.getInstance(pkinfo.getAlgName());
Key secret = skf.generateSecret(pbeSpec);
PKCS8EncodedKeySpec keySpec = pkinfo.getKeySpec(secret);
KeyFactory kf = KeyFactory.getInstance("RSA");
PrivateKey pk=kf.generatePrivate(keySpec);
return pk.toString();
}
我得到这个异常
java.io.IOException: DerInputStream.getLength(): lengthTag=50, too big.
at sun.security.util.DerInputStream.getLength(DerInputStream.java:561)
at sun.security.util.DerValue.init(DerValue.java:365)
at sun.security.util.DerValue.<init>(DerValue.java:294)
at javax.crypto.EncryptedPrivateKeyInfo.<init> (EncryptedPrivateKeyInfo.java:84)
我是否将正确的参数传递给 EncryptedPrivateKeyInfo 构造函数？
我怎样才能让它工作？
我尝试了 Ericsonn 的建议，因为我使用的是 Java 7，所以我做了一个小改动，我无法使用 Base64.getMimeCoder() 而不是我使用了 Base64.decode 并且我收到了这个错误 我在 com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750) 上使用填充密码解密时收到这样的错误输入长度必须是 8 的倍数
static RSAPrivateKey decrypt(String keyDataStr, String ivHex, String password)
throws GeneralSecurityException, UnsupportedEncodingException
{
byte[] pw = password.getBytes(StandardCharsets.UTF_8);
byte[] iv = h2b(ivHex);
SecretKey secret = opensslKDF(pw, iv);
Cipher cipher = Cipher.getInstance("DESede/CBC/NoPadding");
cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
byte [] keyBytes=Base64.decode(keyDataStr.getBytes("UTF-8"));
byte[] pkcs1 = cipher.doFinal(keyBytes);
/* See note for definition of "decodeRSAPrivatePKCS1" */
RSAPrivateCrtKeySpec spec = decodeRSAPrivatePKCS1(pkcs1);
KeyFactory rsa = KeyFactory.getInstance("RSA");
return (RSAPrivateKey) rsa.generatePrivate(spec);
}
private static SecretKey opensslKDF(byte[] pw, byte[] iv)
throws NoSuchAlgorithmException
{
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(pw);
md5.update(iv);
byte[] d0 = md5.digest();
md5.update(d0);
md5.update(pw);
md5.update(iv);
byte[] d1 = md5.digest();
byte[] key = new byte[24];
System.arraycopy(d0, 0, key, 0, 16);
System.arraycopy(d1, 0, key, 16, 8);
return new SecretKeySpec(key, "DESede");
}
private static byte[] h2b(CharSequence s)
{
int len = s.length();
byte[] b = new byte[len / 2];
for (int src = 0, dst = 0; src < len; ++dst) {
int hi = Character.digit(s.charAt(src++), 16);
int lo = Character.digit(s.charAt(src++), 16);
b[dst] = (byte) (hi << 4 | lo);
}
return b;
}
static RSAPrivateCrtKeySpec decodeRSAPrivatePKCS1(byte[] encoded)
{
ByteBuffer input = ByteBuffer.wrap(encoded);
if (der(input, 0x30) != input.remaining())
throw new IllegalArgumentException("Excess data");
if (!BigInteger.ZERO.equals(derint(input)))
throw new IllegalArgumentException("Unsupported version");
BigInteger n = derint(input);
BigInteger e = derint(input);
BigInteger d = derint(input);
BigInteger p = derint(input);
BigInteger q = derint(input);
BigInteger ep = derint(input);
BigInteger eq = derint(input);
BigInteger c = derint(input);
return new RSAPrivateCrtKeySpec(n, e, d, p, q, ep, eq, c);
}
private static BigInteger derint(ByteBuffer input)
{
byte[] value = new byte[der(input, 0x02)];
input.get(value);
return new BigInteger(+1, value);
}
private static int der(ByteBuffer input, int exp)
{
int tag = input.get() & 0xFF;
if (tag != exp)
throw new IllegalArgumentException("Unexpected tag");
int n = input.get() & 0xFF;
if (n < 128)
return n;
n &= 0x7F;
if ((n < 1) || (n > 2))
throw new IllegalArgumentException("Invalid length");
int len = 0;
while (n-- > 0) {
len <<= 8;
len |= input.get() & 0xFF;
}
return len;
}
1640 是 keyDataStr.length() 而 1228 是 keyBytes.length
最佳答案
您需要使用非标准的 OpenSSL 方法来导出解密 key 。然后使用它来解密 PKCS-#1 编码的 key ——您正在使用的不是 PKCS #8 信封。您还需要标题中的 IV 作为这些过程的输入。
看起来像这样:
static RSAPrivateKey decrypt(String keyDataStr, String ivHex, String password)
throws GeneralSecurityException
{
byte[] pw = password.getBytes(StandardCharsets.UTF_8);
byte[] iv = h2b(ivHex);
SecretKey secret = opensslKDF(pw, iv);
Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv));
byte[] pkcs1 = cipher.doFinal(Base64.getMimeDecoder().decode(keyDataStr));
/* See note for definition of "decodeRSAPrivatePKCS1" */
RSAPrivateCrtKeySpec spec = decodeRSAPrivatePKCS1(pkcs1);
KeyFactory rsa = KeyFactory.getInstance("RSA");
return (RSAPrivateKey) rsa.generatePrivate(spec);
}
private static SecretKey opensslKDF(byte[] pw, byte[] iv)
throws NoSuchAlgorithmException
{
MessageDigest md5 = MessageDigest.getInstance("MD5");
md5.update(pw);
md5.update(iv);
byte[] d0 = md5.digest();
md5.update(d0);
md5.update(pw);
md5.update(iv);
byte[] d1 = md5.digest();
byte[] key = new byte[24];
System.arraycopy(d0, 0, key, 0, 16);
System.arraycopy(d1, 0, key, 16, 8);
return new SecretKeySpec(key, "DESede");
}
private static byte[] h2b(CharSequence s)
{
int len = s.length();
byte[] b = new byte[len / 2];
for (int src = 0, dst = 0; src < len; ++dst) {
int hi = Character.digit(s.charAt(src++), 16);
int lo = Character.digit(s.charAt(src++), 16);
b[dst] = (byte) (hi << 4 | lo);
}
return b;
}
这已经是很多代码了，所以我将链接到另一个关于 the decodeRSAPrivatePKCS1() method. 定义的答案。
关于java - 使用 Java 解密 OpenSSL PEM 编码的 RSA 私钥？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35276820/