php实现rsa签名和验签

这两天在弄某支付接口相关的东西,以前没做过这块,在签名和验签的过程中遇到了一些问题,记下来.

首先生成一个1024位的私钥:

openssl genrsa -out private.pem 1024

然后根据私钥导出公钥

openssl rsa -in private.pem -pubout -out public.pem

php的openssl扩展里已经封装好了签名和验签的方法,分别是openssl\_sign和openssl\_verify.

function sign($data){
    $p = openssl_pkey_get_private(file_get_contents('private.pem'));
    openssl_sign($data, $signature, $p);
    openssl_free_key($p);
    return bin2hex($signature);
}

function verify($data, $sign){
    $p = openssl_pkey_get_public(file_get_contents('public.pem'));
    $verify = openssl_verify($data, hex2bin($sign), $p);
    openssl_free_key($p);
    return $verify > 0;
}

实际情况是测试接口并没有提供公私钥,而是提供了公/私钥指数,模数.通过java的RSAPrivateKeySpec和RSAPublicKeySpec来实现签名和验签,遂写了一个jar用命令行来调用:

package org;
        
import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.Signature;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
        
/**
    * @author eslizn
    *
    */
public class SignVerify {
        
        /**
        * @param args
        * @throws Exception
        */
        public static void main(String[] args) throws Exception {
            if(args.length == 4 && args[0].equals("sign")){
                System.out.println(Sign(args[1], new BigInteger(args[2], 16), new BigInteger(args[3], 16)));
                System.exit(0);
            }
        
            if(args.length == 5 && args[0].equals("verify")){
                System.out.println(Verify(args[1], args[2], new BigInteger(args[3], 16), new BigInteger(args[4], 16)) ? "1" : "0");
                System.exit(0);
            }
        }
        
        /**
        * Sign
        *
        * @param data
        * @param mod
        * @param exp
        * @return
        * @throws Exception
        */
        public static String Sign(String data, BigInteger mod, BigInteger exp) throws Exception{
            RSAPrivateKeySpec spec = new RSAPrivateKeySpec(mod, exp);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey signKey = keyFactory.generatePrivate(spec);
            Signature signature = Signature.getInstance("SHA1withRSA");
            signature.initSign(signKey);
            signature.update(data.getBytes());
            return byteArray2HexString(signature.sign());
        }
        
        /**
        * Verify
        *
        * @param data
        * @param sign
        * @param mod
        * @param exp
        * @return
        * @throws Exception
        */
        public static boolean Verify(String data, String sign, BigInteger mod, BigInteger exp) throws Exception{
            RSAPublicKeySpec spec = new RSAPublicKeySpec(mod, exp);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            java.security.PublicKey verifyKey = keyFactory.generatePublic(spec);
            Signature verifier = Signature.getInstance("SHA1withRSA");
            verifier.initVerify(verifyKey);
            verifier.update(data.getBytes());
            return verifier.verify(hexString2ByteArray(sign));
        }
        
        public static byte[] hexString2ByteArray(String hexStr){
            if (hexStr == null)
                return null;
            if (hexStr.length() % 2 != 0)
                return null;
            byte data[] = new byte[hexStr.length() / 2];
            for (int i = 0; i < hexStr.length() / 2; i++){
                char hc = hexStr.charAt(2 * i);
                char lc = hexStr.charAt(2 * i + 1);
                byte hb = hexChar2Byte(hc);
                byte lb = hexChar2Byte(lc);
                if (hb < 0 || lb < 0)
                    return null;
                int n = hb << 4;
                data[i] = (byte)(n + lb);
            }
        return data;
    }
        
    public static byte hexChar2Byte(char c){
        if (c >= '0' && c <= '9')
            return (byte)(c - 48);
        if (c >= 'a' && c <= 'f')
            return (byte)((c - 97) + 10);
        if (c >= 'A' && c <= 'F')
            return (byte)((c - 65) + 10);
        else
            return -1;
    }
        
    public static String byteArray2HexString(byte arr[]){
        StringBuilder sbd = new StringBuilder();
        byte arr$[] = arr;
        int len$ = arr$.length;
        for (int i$ = 0; i$ < len$; i$++){
        byte b = arr$[i$];
        String tmp = Integer.toHexString(0xff & b);
        if (tmp.length() < 2)
            tmp = (new StringBuilder()).append("0").append(tmp).toString();
            sbd.append(tmp);
        }
        return sbd.toString();
    }
}

巧合的是写完后通过沟通,对方要我们自行生成一对公私钥后将其中的公/私钥指数和模数发给他们.有的时候可能有的办法比技术实现更方便.附上取公/私钥指数和模数的代码:

function getPrivate($file){
    $p = openssl_pkey_get_private(file_get_contents($file));
    $res = openssl_pkey_get_details($p);
    var_dump($res);
    openssl_free_key($p);
    return array(
        'n' => bin2hex($res['rsa']['n']),#模数
        'e' => bin2hex($res['rsa']['e']),#公钥指数
        'd' => bin2hex($res['rsa']['d']),#私钥指数
    );
}