签名长度不正确：得到 768 但预期为 512，在 Java 中验证
Signature length not correct: got 768 but was expecting 512, in Java verify
我已经在 java 中发布了一个关于如何加载 RSA 密钥的类似问题。查看 问题的最佳回复以完全理解我的代码的第一部分（方法 getPulicKey，我是说）。
private static PublicKey getPublicKey(String publicKey)
throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
try (PEMParser pp = new PEMParser(new StringReader(publicKey))) {
SubjectPublicKeyInfo subjPubKeyInfo = (SubjectPublicKeyInfo) pp.readObject();
RSAKeyParameters rsa = (RSAKeyParameters) PublicKeyFactory.createKey(subjPubKeyInfo);
RSAPublicKeySpec rsaSpec = new RSAPublicKeySpec(rsa.getModulus(), rsa.getExponent());
KeyFactory kf = KeyFactory.getInstance("RSA");
PublicKey myKey = kf.generatePublic(rsaSpec);
System.out.println(myKey);
return myKey;
}
}
验证方法（下方）引发以下异常
Signature length not correct: got 768 but was expecting 512, in Java verify
在下面的代码中，我对签名进行了解码，因为我认为它是 Base64，但我不确定，抱歉。我不知道我是否可以给你看签名和对象。签名是 1024 位数字和数字的序列。它不以“=”结尾。我要验证的对象是字符串格式的 json 对象。
以下是我编写的验证字符串对象的方法，给定一个符号和一个 publicKey。它调用上面的方法 getPublicKey(...).
public static boolean verify(String object, String sign, String publicKey) throws NoSuchAlgorithmException,
InvalidKeySpecException, IOException, InvalidKeyException, SignatureException {
//object to be verified
//sign is the signature stored in the postgres DB
//publicKey is the public key stored in the postgres DB
Signature signature = Signature.getInstance("SHA256withRSA");
signature.initVerify(getPublicKey(publicKey));
byte[] objectBytes = Base64.getEncoder().encode(object.getBytes("utf-8"));
signature.update(objectBytes);
byte[] signBytes = Base64.getDecoder().decode(sign.getBytes("utf-8"));
System.out.println(signBytes.length); //this line prints 768, with decode. 1024, otherwhise
return signature.verify(signBytes);
}
编辑：
我的同事正在使用以下两个 nodejs 方法（verifySign 和 createSign）。
在下面的nodejs代码中（有工友的方法），我用"createSign"加密了消息"fake message"。符号如下：
5f188225c68dee2ce8de588dfaccb667710da94abb5388deabfe3ad83f7a94a72ee4a3c8c51be26c5b58cdec8c82cf8135c478ad609b7985496e201b23de6c5d03e93dcd9df7b5e2315efbfd2ff6496b0aea3b425bb99c912a16aeb5efb6cefc1e175c32aaf16af3a2baca5b54f974af0f14c853228bc06410e7ad1b2b0ecec19f5aed151389bd9ccebd5e998159d5205d81a7c7e37b502df3eb5229a5fd3492680576ebfa1e76b7c47fb757a9bfb18aa9ea0b71512ab9e1afc8e551ebf6d74a042bd447233953efbf374a3a6a210ead2019b8cc8548bb304979b4bfdc90dce644cb109bbddb75dda9df1322fd8e08ef1144e870324f34d4c826d9a4b64be0442aedc6f3d5f571d7336af212825c4e0216aa5eabab6218d685a3e73d81693149b45af5f1857c4a0e50b396d1a2ea5a3effafcc4e124fd23d0427abfe5509357936ef5e7c7ca4476d6a5ae7a26e9563923a03d0780f0d897039d4d3aa2ce49dc84b31907a50045456acb57edd11a896632969245d0f97fd88dace7eb256099bbc4eedf52b5d53b481b2aeb829101d0089903ea9c3621bcbd763962b84ad57407623b576cc6a9c3328d85e0f7dd78565cd39a6648a68dd6f4334dd3a68e48491ae655601a5c9be7673ae0d3f955431fb21f33c0178ecb9067072a6b1e360ee77a45f8e855e6c545276aefc7ae70b5c7e0f1ec0b66460575e3386f8a4bbf7fd3704
然后，我用 public 密钥 pk 验证它（见下文）。
const PASSPHRASE_KEY = "...";
const crypto = require('crypto');
const prk = "...";
const pk = "-----BEGIN RSA PUBLIC KEY-----\r\n" +
"MIICCgKCAgEA1ht0OqZpP7d/05373OE7pB7yCVGNGzkUEuCneyfOzps6iA03NbvI\r\n" +
"1ZL0Jpp/N3AW73lGdhaoa3X3JE4GsI/bsToVLQwTKmIOC4yjTvBctmFEoyhhTfxW\r\n" +
"s1UHZKl4XZ/7THbRlKHhRaTKyfDAbikkMAxNT/qutLAPjnN1qOwjb1oRq52NP6FJ\r\n" +
"KWTTikz4UeOHroX+Xthn2fJSJDlQ4YMdBbgrZVx5JcHKNuPTKRf5gI8QQKMSA9Q9\r\n" +
"QJRE5OGp7b6dG14ZmOUnUxb00Mp20LgcaGPcuWU+oFsbQaF6W4G4bdkSZRJJXhSg\r\n" +
"d4Q7mahpar94/gnztJmth0GzqTWUYyZIWNqIFoMwuOgeaiDV43zb3uLsRVpRKYYy\r\n" +
"esmzcOy/jTScVLRCD8QRyu9B2wgCkNAVztQOXPCOOa4O1LlVQWaecIs4WPhOqDhi\r\n" +
"KTBhyVkpC1TrrBkp+QMqMqWll1OyVb6k/7uV0qE/i6rHJtjo5v9bcIgYzswyx9CD\r\n" +
"9PKl2Q0L0Jg7TMG+yLDIrLfGeuSeEc4XYJzN7bJcCeiizzu5iU9dQUkrncOrq9jn\r\n" +
"Ub2pM/+A+JqIsoPK3IY/pJKqH4JYpGKhO1iPQF6iXIZT1r3ZgJUSQtzSeyYqhkla\r\n" +
"2uR2BsbPbDqebCuXm3lAsY5w+dujijcn96PKwYha1LsK5sACHuJ79AMCAwEAAQ==\r\n" +
"-----END RSA PUBLIC KEY-----\r\n" +
"";
function createSign(pvt_key, data_unsigned) {
//Create a SHA256 sign generator
const signer = crypto.createSign('SHA256');
//Update context with data to sign
signer.update(data_unsigned);
//Sign the document based to user's private key
return signer.sign({
key: pvt_key,
passphrase: PASSPHRASE_KEY
},
'hex'
);
}
function verifySign(pub_key, signed_data, signature) {
const verifier = crypto.createVerify('sha256');
//Update context with data to verify
verifier.update(signed_data);
//Verify sign with user's public key
const verified = verifier.verify(
pub_key,
signature,
'hex'
);
//Send result
return verified;
}
const phrase = "fake message";
var signMade = createSign(prk, phrase);
console.log("my signature: " + signMade);
//The signature is 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
console.log("was it me to sign that?");
var res = verifySign(pk, phrase, signMade);
console.log(res);
它 returns 是的。但是，如果我传递给 java 方法，请验证以下（相同）参数：
- 对象="fake message"
- sign = 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 c7e0f1ec0b66460575e3386f8a4bbf7fd3704
- public从 pk 复制的密钥（参见上面的节点代码）
java 引发异常：
Signature length not correct: got 768 but was expecting 512
Signature lenght not correct.
您将签名视为 base64 编码，但它不是 - 它只是十六进制。
1024 个字符表示 768 个 base64 编码字节，或 512 个十六进制编码字节。
只要使用十六进制而不是 base64 解码就可以了。
提示这是正确的，并观察到您签名的每个字符都是有效的十六进制数字（如果它实际上是 base64，则极不可能） :
return signer.sign({
key: pvt_key,
passphrase: PASSPHRASE_KEY
},
'hex' // Note this use of 'hex'...
);
我已经在 java 中发布了一个关于如何加载 RSA 密钥的类似问题。查看
private static PublicKey getPublicKey(String publicKey)
throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
try (PEMParser pp = new PEMParser(new StringReader(publicKey))) {
SubjectPublicKeyInfo subjPubKeyInfo = (SubjectPublicKeyInfo) pp.readObject();
RSAKeyParameters rsa = (RSAKeyParameters) PublicKeyFactory.createKey(subjPubKeyInfo);
RSAPublicKeySpec rsaSpec = new RSAPublicKeySpec(rsa.getModulus(), rsa.getExponent());
KeyFactory kf = KeyFactory.getInstance("RSA");
PublicKey myKey = kf.generatePublic(rsaSpec);
System.out.println(myKey);
return myKey;
}
}
验证方法（下方）引发以下异常
Signature length not correct: got 768 but was expecting 512, in Java verify
在下面的代码中，我对签名进行了解码，因为我认为它是 Base64，但我不确定，抱歉。我不知道我是否可以给你看签名和对象。签名是 1024 位数字和数字的序列。它不以“=”结尾。我要验证的对象是字符串格式的 json 对象。 以下是我编写的验证字符串对象的方法，给定一个符号和一个 publicKey。它调用上面的方法 getPublicKey(...).
public static boolean verify(String object, String sign, String publicKey) throws NoSuchAlgorithmException,
InvalidKeySpecException, IOException, InvalidKeyException, SignatureException {
//object to be verified
//sign is the signature stored in the postgres DB
//publicKey is the public key stored in the postgres DB
Signature signature = Signature.getInstance("SHA256withRSA");
signature.initVerify(getPublicKey(publicKey));
byte[] objectBytes = Base64.getEncoder().encode(object.getBytes("utf-8"));
signature.update(objectBytes);
byte[] signBytes = Base64.getDecoder().decode(sign.getBytes("utf-8"));
System.out.println(signBytes.length); //this line prints 768, with decode. 1024, otherwhise
return signature.verify(signBytes);
}
编辑：
我的同事正在使用以下两个 nodejs 方法（verifySign 和 createSign）。
在下面的nodejs代码中（有工友的方法），我用"createSign"加密了消息"fake message"。符号如下：
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
然后，我用 public 密钥 pk 验证它（见下文）。
const PASSPHRASE_KEY = "...";
const crypto = require('crypto');
const prk = "...";
const pk = "-----BEGIN RSA PUBLIC KEY-----\r\n" +
"MIICCgKCAgEA1ht0OqZpP7d/05373OE7pB7yCVGNGzkUEuCneyfOzps6iA03NbvI\r\n" +
"1ZL0Jpp/N3AW73lGdhaoa3X3JE4GsI/bsToVLQwTKmIOC4yjTvBctmFEoyhhTfxW\r\n" +
"s1UHZKl4XZ/7THbRlKHhRaTKyfDAbikkMAxNT/qutLAPjnN1qOwjb1oRq52NP6FJ\r\n" +
"KWTTikz4UeOHroX+Xthn2fJSJDlQ4YMdBbgrZVx5JcHKNuPTKRf5gI8QQKMSA9Q9\r\n" +
"QJRE5OGp7b6dG14ZmOUnUxb00Mp20LgcaGPcuWU+oFsbQaF6W4G4bdkSZRJJXhSg\r\n" +
"d4Q7mahpar94/gnztJmth0GzqTWUYyZIWNqIFoMwuOgeaiDV43zb3uLsRVpRKYYy\r\n" +
"esmzcOy/jTScVLRCD8QRyu9B2wgCkNAVztQOXPCOOa4O1LlVQWaecIs4WPhOqDhi\r\n" +
"KTBhyVkpC1TrrBkp+QMqMqWll1OyVb6k/7uV0qE/i6rHJtjo5v9bcIgYzswyx9CD\r\n" +
"9PKl2Q0L0Jg7TMG+yLDIrLfGeuSeEc4XYJzN7bJcCeiizzu5iU9dQUkrncOrq9jn\r\n" +
"Ub2pM/+A+JqIsoPK3IY/pJKqH4JYpGKhO1iPQF6iXIZT1r3ZgJUSQtzSeyYqhkla\r\n" +
"2uR2BsbPbDqebCuXm3lAsY5w+dujijcn96PKwYha1LsK5sACHuJ79AMCAwEAAQ==\r\n" +
"-----END RSA PUBLIC KEY-----\r\n" +
"";
function createSign(pvt_key, data_unsigned) {
//Create a SHA256 sign generator
const signer = crypto.createSign('SHA256');
//Update context with data to sign
signer.update(data_unsigned);
//Sign the document based to user's private key
return signer.sign({
key: pvt_key,
passphrase: PASSPHRASE_KEY
},
'hex'
);
}
function verifySign(pub_key, signed_data, signature) {
const verifier = crypto.createVerify('sha256');
//Update context with data to verify
verifier.update(signed_data);
//Verify sign with user's public key
const verified = verifier.verify(
pub_key,
signature,
'hex'
);
//Send result
return verified;
}
const phrase = "fake message";
var signMade = createSign(prk, phrase);
console.log("my signature: " + signMade);
//The signature is 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
console.log("was it me to sign that?");
var res = verifySign(pk, phrase, signMade);
console.log(res);
它 returns 是的。但是，如果我传递给 java 方法，请验证以下（相同）参数：
- 对象="fake message"
- sign = 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 c7e0f1ec0b66460575e3386f8a4bbf7fd3704
- public从 pk 复制的密钥（参见上面的节点代码）
java 引发异常：
Signature length not correct: got 768 but was expecting 512 Signature lenght not correct.
您将签名视为 base64 编码，但它不是 - 它只是十六进制。
1024 个字符表示 768 个 base64 编码字节，或 512 个十六进制编码字节。
只要使用十六进制而不是 base64 解码就可以了。
提示这是正确的，并观察到您签名的每个字符都是有效的十六进制数字（如果它实际上是 base64，则极不可能） :
return signer.sign({
key: pvt_key,
passphrase: PASSPHRASE_KEY
},
'hex' // Note this use of 'hex'...
);