android签名机制4

最新推荐文章于 2023-05-29 00:16:54 发布

HTYBAY

最新推荐文章于 2023-05-29 00:16:54 发布

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接着上篇，继续来分析签名过程，先看张简易的时序图：

主要对签名时的命令行进行分析：
java -jar signapk.jar platform.x509.pem platform.pk8 **.apk ***.apk

注：如果对已签名的apk执行该命令，会重新覆盖已有的签名信息，故印证前面说讲的支持多次签名，以最后一次为准

signapk代码位于android源码路径：

SignApk.java (build\tools\signapk)

是个可执行程序，代码只有514行，具体可参考代码。

 
        public 
         static 
         void 
         main(String[] args) { 
       
        if 
         (args.length !=  
        4 
         && args.length !=  
        5 
        ) { 
       
        System.err.println( 
        "Usage: signapk [-w] " 
         + 
       
        "publickey.x509[.pem] privatekey.pk8 " 
         + 
       
        "input.jar output.jar" 
        ); 
       
        System.exit( 
        2 
        ); 
       
        } 
       
        boolean 
         signWholeFile =  
        false 
        ; 
       
        int 
         argstart =  
        0 
        ; 
       
        if 
         (args[ 
        0 
        ].equals( 
        "-w" 
        )) { 
       
        signWholeFile =  
        true 
        ; 
       
        argstart =  
        1 
        ; 
       
        } 
       
        JarFile inputJar =  
        null 
        ; 
       
        JarOutputStream outputJar =  
        null 
        ; 
       
        FileOutputStream outputFile =  
        null 
        ; 
       
        try 
         { 
       
        X509Certificate publicKey = readPublicKey( 
        new 
         File(args[argstart+ 
        0 
        ])); 
       
        // Assume the certificate is valid for at least an hour. 
       
        long 
         timestamp = publicKey.getNotBefore().getTime() + 3600L *  
        1000 
        ; 
       
        PrivateKey privateKey = readPrivateKey( 
        new 
         File(args[argstart+ 
        1 
        ])); 
       
        inputJar =  
        new 
         JarFile( 
        new 
         File(args[argstart+ 
        2 
        ]),  
        false 
        );   
        // Don't verify. 
       
        OutputStream outputStream =  
        null 
        ; 
       
        if 
         (signWholeFile) { 
       
        outputStream =  
        new 
         ByteArrayOutputStream(); 
       
        }  
        else 
         { 
       
        outputStream = outputFile =  
        new 
         FileOutputStream(args[argstart+ 
        3 
        ]); 
       
        } 
       
        outputJar =  
        new 
         JarOutputStream(outputStream); 
       
        outputJar.setLevel( 
        9 
        ); 
       
        JarEntry je; 
       
        // MANIFEST.MF 
       
        Manifest manifest = addDigestsToManifest(inputJar); 
       
        je =  
        new 
         JarEntry(JarFile.MANIFEST_NAME); 
       
        je.setTime(timestamp); 
       
        outputJar.putNextEntry(je); 
       
        manifest.write(outputJar); 
       
        // CERT.SF 
       
        Signature signature = Signature.getInstance( 
        "SHA1withRSA" 
        ); 
       
        signature.initSign(privateKey); 
       
        je =  
        new 
         JarEntry(CERT_SF_NAME); 
       
        je.setTime(timestamp); 
       
        outputJar.putNextEntry(je); 
       
        writeSignatureFile(manifest, 
       
        new 
         SignatureOutputStream(outputJar, signature)); 
       
        // CERT.RSA 
       
        je =  
        new 
         JarEntry(CERT_RSA_NAME); 
       
        je.setTime(timestamp); 
       
        outputJar.putNextEntry(je); 
       
        writeSignatureBlock(signature, publicKey, outputJar); 
       
        // Everything else 
       
        copyFiles(manifest, inputJar, outputJar, timestamp); 
       
        outputJar.close(); 
       
        outputJar =  
        null 
        ; 
       
        outputStream.flush(); 
       
        if 
         (signWholeFile) { 
       
        outputFile =  
        new 
         FileOutputStream(args[argstart+ 
        3 
        ]); 
       
        signWholeOutputFile(((ByteArrayOutputStream)outputStream).toByteArray(), 
       
        outputFile, publicKey, privateKey); 
       
        } 
       
        }  
        catch 
         (Exception e) { 
       
        e.printStackTrace(); 
       
        System.exit( 
        1 
        ); 
       
        }  
        finally 
         { 
       
        try 
         { 
       
        if 
         (inputJar !=  
        null 
        ) inputJar.close(); 
       
        if 
         (outputFile !=  
        null 
        ) outputFile.close(); 
       
        }  
        catch 
         (IOException e) { 
       
        e.printStackTrace(); 
       
        System.exit( 
        1 
        ); 
       
        } 
       
        } 
       
        }