关于amazon-web-services:Java实现AWS-S3-V4-Authorization自定义验证

前言

最近在开发文件存储服务，须要合乎s3的协定规范，能够间接接入aws-sdk，本文针对sdk发出请求的鉴权信息进行重新组合再签名验证有效性，sdk版本如下

        <dependency>            <groupId>software.amazon.awssdk</groupId>            <artifactId>s3</artifactId>            <version>2.20.45</version>        </dependency>

算法解析

首先对V4版本签名算法的数据结构及签名流程进行拆解剖析，以申请头签名为示例解说

signature = doSign(waitSignString)

签名示例

申请头签名

AWS4-HMAC-SHA256 Credential=admin/20230530/us-east-1/s3/aws4_request, SignedHeaders=amz-sdk-invocation-id;amz-sdk-request;host;x-amz-content-sha256;x-amz-date, Signature=6f50628a101b46264c7783937be0366762683e0d319830b1844643e40b3b0ed

Url签名

http://localhost:8001/s3/kkk/test.docx?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20230531T024715Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=admin%2F20230531%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=038e2ea71073761aa0370215621599649e9228177c332a0a79f784b1a6d9ee39

数据结构

waitSignString = doHex（【第一局部】+【第二局部】+【第三局部】+【第四局部】），每局部应用\n换行符连贯，第四局部不要加上换行符

第一局部

Algorithm – 用于创立标准申请的哈希的算法，对于 SHA-256，算法是 AWS4-HMAC-SHA256，则这部分的内容固定为

"AWS4-HMAC-SHA256" + "\n"

第二局部

RequestDateTime – 在凭证范畴内应用的日期和工夫，这个工夫为申请收回的工夫，间接从申请头获取x-amz-date即可，这部分内容为

request.getHeader("x-amz-date") + "\n"

第三局部

CredentialScope – 凭证范畴，这会将生成的签名限度在指定的区域和服务范畴内，该字符串采纳以下格局：YYYYMMDD/region/service/aws4_request

这部分由4个内容信息拼接组成

申请工夫的YYYYMMDD格局
存储区域
存储服务
申请头

这些信息咱们都能够从申请头的Authorization凭证提取出Credential局部进行拆分重新组合

        String[] parts = authorization.trim().split("\\,");        String credential = parts[0].split("\\=")[1];        String[] credentials = credential.split("\\/");        String accessKey = credentials[0];        if (!accessKeyId.equals(accessKey)) {            return false;        }        String date = credentials[1];        String region = credentials[2];        String service = credentials[3];        String aws4Request = credentials[4];

这部分内容为

date + "/" + region + "/" + service + "/" + aws4Request + "\n"

第四局部

HashedCanonicalRequest – 标准申请的哈希

这部分内容为

doHex(canonicalRequest)

canonicalRequest具体拆解又能够6小局部组成，每局部应用\n换行符连贯，最初不要加上换行符

<HTTPMethod>\n<CanonicalURI>\n<CanonicalQueryString>\nCanonicalHeaders>\n<SignedHeaders>\n<HashedPayload>

HTTPMethod
代表申请的HTTP办法，例如GET，POST，DELETE，PUT等，间接从request获取即可
这部分内容为
```
String HTTPMethod = request.getMethod() + "\n"
```
CanonicalURI
代表申请的路由局部，例如实现申请为http://localhost:8001/s3/aaaa/ccc.txt，则该局部为/s3/aaaa/ccc.txt
须要进行encode操作，我这里间接获取则省略了这部分
这部分内容为
```
String CanonicalURI = request.getRequestURI().split("\\?")[0] + "\n";
```

CanonicalQueryString

代表申请参数的拼接成字符串key1=value1&key2=value2这种模式，拼接的key须要依照字母排序

value须要进行encode操作，我这里间接获取则省略了这部分

        String queryString = ConvertOp.convert2String(request.getQueryString());        if(!StringUtil.isEmpty(queryString)){            Map<String, String> queryStringMap =  parseQueryParams(queryString);            List<String> keyList = new ArrayList<>(queryStringMap.keySet());            Collections.sort(keyList);            StringBuilder queryStringBuilder = new StringBuilder("");            for (String key:keyList) {                queryStringBuilder.append(key).append("=").append(queryStringMap.get(key)).append("&");            }            queryStringBuilder.deleteCharAt(queryStringBuilder.lastIndexOf("&"));        }    public static Map<String, String> parseQueryParams(String queryString) {        Map<String, String> queryParams = new HashMap<>();        try {            if (queryString != null && !queryString.isEmpty()) {                String[] queryParamsArray = queryString.split("\\&");                for (String param : queryParamsArray) {                    String[] keyValue = param.split("\\=");                    if (keyValue.length == 1) {                        String key = keyValue[0];                        String value = "";                        queryParams.put(key, value);                    }                    else if (keyValue.length == 2) {                        String key = keyValue[0];                        String value = keyValue[1];                        queryParams.put(key, value);                    }                }            }        } catch (Exception e) {            e.printStackTrace();        }        return queryParams;    }

这部分内容为

String CanonicalQueryString = queryStringBuilder.toString() + "\n"

CanonicalHeaders

代表申请头拼接成字符串key:value的模式，每个head局部应用\n换行符连贯，拼接的key须要依照字母排序

签名的申请头从Authorization解析获取

        String signedHeader = parts[1].split("\\=")[1];        String[] signedHeaders = signedHeader.split("\\;");

        String headString = "";        for (String name : signedHeaders) {            headString += name + ":" + request.getHeader(name) + "\n";        }

这部分内容为

String CanonicalHeaders = headString + "\n"

SignedHeaders
代表申请头的key局部，应用;隔开
这部分内容为从Authorization解析中获取
这部分内容为
```
String SignedHeaders = signedHeader + "\n"
```
HashedPayload
代表申请body局部的签名，间接从requet的head提取x-amz-content-sha256内容
这部分内容为
```
String HashedPayload = Stringrequest.getHeader("x-amz-content-sha256")
```

doHex

本局部只是一个字符串转16进制的一个操作

    private String doHex(String data) {        MessageDigest messageDigest;        try {            messageDigest = MessageDigest.getInstance("SHA-256");            messageDigest.update(data.getBytes("UTF-8"));            byte[] digest = messageDigest.digest();            return String.format("%064x", new java.math.BigInteger(1, digest));        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {            e.printStackTrace();        }        return null;    }

签名流程

doSign 的流程为doBytesToHex（doHmacSHA256（signatureKey，waitSignString ））

doBytesToHex为byte转16进制操作

    private String doBytesToHex(byte[] bytes) {        char[] hexChars = new char[bytes.length * 2];        for (int j = 0; j < bytes.length; j++) {            int v = bytes[j] & 0xFF;            hexChars[j * 2] = hexArray[v >>> 4];            hexChars[j * 2 + 1] = hexArray[v & 0x0F];        }        return new String(hexChars).toLowerCase();    }

doHmacSHA256为签名算法

    private byte[] doHmacSHA256(byte[] key, String data) throws Exception {        String algorithm = "HmacSHA256";        Mac mac = Mac.getInstance(algorithm);        mac.init(new SecretKeySpec(key, algorithm));        return mac.doFinal(data.getBytes("UTF8"));    }

signatureKey签名密钥由secretAccessKey，申请工夫，存储区域，存储服务，申请头这5个因素进行叠加签名生成

        byte[] kSecret = ("AWS4" + secretAccessKey).getBytes("UTF8");        byte[] kDate = doHmacSHA256(kSecret, date);        byte[] kRegion = doHmacSHA256(kDate, region);        byte[] kService = doHmacSHA256(kRegion, service);        byte[] signatureKey = doHmacSHA256(kService, aws4Request);

将最终生成的再签名与Authorization中解析出的Signature进行比拟，统一则鉴权胜利

调试地位

调试过程中须要验证每局部的签名是否拼接编码正确，咱们须要和sdk生成的内容进行比对找出问题

调试software.amazon.awssdk.auth.signer.internal包下AbstractAws4Signer类的doSign类，获取stringToSign与你待签名字符串比对差别，源码如下

    protected Builder doSign(SdkHttpFullRequest request, Aws4SignerRequestParams requestParams, T signingParams, ContentChecksum contentChecksum) {        Builder mutableRequest = request.toBuilder();        AwsCredentials sanitizedCredentials = this.sanitizeCredentials(signingParams.awsCredentials());        if (sanitizedCredentials instanceof AwsSessionCredentials) {            this.addSessionCredentials(mutableRequest, (AwsSessionCredentials)sanitizedCredentials);        }        this.addHostHeader(mutableRequest);        this.addDateHeader(mutableRequest, requestParams.getFormattedRequestSigningDateTime());        mutableRequest.firstMatchingHeader("x-amz-content-sha256").filter((h) -> {            return h.equals("required");        }).ifPresent((h) -> {            mutableRequest.putHeader("x-amz-content-sha256", contentChecksum.contentHash());        });        this.putChecksumHeader(signingParams.checksumParams(), contentChecksum.contentFlexibleChecksum(), mutableRequest, contentChecksum.contentHash());        AbstractAws4Signer.CanonicalRequest canonicalRequest = this.createCanonicalRequest(request, mutableRequest, contentChecksum.contentHash(), signingParams.doubleUrlEncode(), signingParams.normalizePath());        String canonicalRequestString = canonicalRequest.string();        String stringToSign = this.createStringToSign(canonicalRequestString, requestParams);        byte[] signingKey = this.deriveSigningKey(sanitizedCredentials, requestParams);        byte[] signature = this.computeSignature(stringToSign, signingKey);        mutableRequest.putHeader("Authorization", this.buildAuthorizationHeader(signature, sanitizedCredentials, requestParams, canonicalRequest));        this.processRequestPayload(mutableRequest, signature, signingKey, requestParams, signingParams, contentChecksum.contentFlexibleChecksum());        return mutableRequest;    }

代码示例

通过拦截器进行验证的过程，残缺代码如下，兼容了一般申请的头部验证和文件下载url的签名验证

@Componentpublic class S3Intecept implements HandlerInterceptor {    @Autowired    private SystemConfig systemConfig;    @Override    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {        boolean flag = false;        String authorization = request.getHeader("Authorization");        if(!StringUtil.isEmpty(authorization)){            flag = validAuthorizationHead(request, systemConfig.getUsername(), systemConfig.getPassword());        }else{            authorization = request.getParameter("X-Amz-Credential");            if(!StringUtil.isEmpty(authorization)){                flag = validAuthorizationUrl(request, systemConfig.getUsername(), systemConfig.getPassword());            }        }        if(!flag){            response.setStatus(HttpStatus.UNAUTHORIZED.value());        }        return flag;    }    public boolean validAuthorizationHead(HttpServletRequest request, String accessKeyId, String secretAccessKey) throws Exception {        String authorization = request.getHeader("Authorization");        String requestDate = request.getHeader("x-amz-date");        String contentHash = request.getHeader("x-amz-content-sha256");        String httpMethod = request.getMethod();        String uri = request.getRequestURI().split("\\?")[0];        String queryString = ConvertOp.convert2String(request.getQueryString());        //示例        //AWS4-HMAC-SHA256 Credential=admin/20230530/us-east-1/s3/aws4_request, SignedHeaders=amz-sdk-invocation-id;amz-sdk-request;host;x-amz-content-sha256;x-amz-date, Signature=6f50628a101b46264c7783937be0366762683e0d319830b1844643e40b3b0ed        ///region authorization拆分        String[] parts = authorization.trim().split("\\,");        //第一局部-凭证范畴        String credential = parts[0].split("\\=")[1];        String[] credentials = credential.split("\\/");        String accessKey = credentials[0];        if (!accessKeyId.equals(accessKey)) {            return false;        }        String date = credentials[1];        String region = credentials[2];        String service = credentials[3];        String aws4Request = credentials[4];        //第二局部-签名头中蕴含哪些字段        String signedHeader = parts[1].split("\\=")[1];        String[] signedHeaders = signedHeader.split("\\;");        //第三局部-生成的签名        String signature = parts[2].split("\\=")[1];        ///endregion        ///region 待签名字符串        String stringToSign = "";        //签名由4局部组成        //1-Algorithm – 用于创立标准申请的哈希的算法。对于 SHA-256，算法是 AWS4-HMAC-SHA256。        stringToSign += "AWS4-HMAC-SHA256" + "\n";        //2-RequestDateTime – 在凭证范畴内应用的日期和工夫。        stringToSign += requestDate + "\n";        //3-CredentialScope – 凭证范畴。这会将生成的签名限度在指定的区域和服务范畴内。该字符串采纳以下格局：YYYYMMDD/region/service/aws4_request        stringToSign += date + "/" + region + "/" + service + "/" + aws4Request + "\n";        //4-HashedCanonicalRequest – 标准申请的哈希。        //<HTTPMethod>\n        //<CanonicalURI>\n        //<CanonicalQueryString>\n        //<CanonicalHeaders>\n        //<SignedHeaders>\n        //<HashedPayload>        String hashedCanonicalRequest = "";        //4.1-HTTP Method        hashedCanonicalRequest += httpMethod + "\n";        //4.2-Canonical URI        hashedCanonicalRequest += uri + "\n";        //4.3-Canonical Query String        if(!StringUtil.isEmpty(queryString)){            Map<String, String> queryStringMap =  parseQueryParams(queryString);            List<String> keyList = new ArrayList<>(queryStringMap.keySet());            Collections.sort(keyList);            StringBuilder queryStringBuilder = new StringBuilder("");            for (String key:keyList) {                queryStringBuilder.append(key).append("=").append(queryStringMap.get(key)).append("&");            }            queryStringBuilder.deleteCharAt(queryStringBuilder.lastIndexOf("&"));            hashedCanonicalRequest += queryStringBuilder.toString() + "\n";        }else{            hashedCanonicalRequest += queryString + "\n";        }        //4.4-Canonical Headers        for (String name : signedHeaders) {            hashedCanonicalRequest += name + ":" + request.getHeader(name) + "\n";        }        hashedCanonicalRequest += "\n";        //4.5-Signed Headers        hashedCanonicalRequest += signedHeader + "\n";        //4.6-Hashed Payload        hashedCanonicalRequest += contentHash;        stringToSign += doHex(hashedCanonicalRequest);        ///endregion        ///region 从新生成签名        //计算签名的key        byte[] kSecret = ("AWS4" + secretAccessKey).getBytes("UTF8");        byte[] kDate = doHmacSHA256(kSecret, date);        byte[] kRegion = doHmacSHA256(kDate, region);        byte[] kService = doHmacSHA256(kRegion, service);        byte[] signatureKey = doHmacSHA256(kService, aws4Request);        //计算签名        byte[] authSignature = doHmacSHA256(signatureKey, stringToSign);        //对签名编码解决        String strHexSignature = doBytesToHex(authSignature);        ///endregion        if (signature.equals(strHexSignature)) {            return true;        }        return false;    }    public boolean validAuthorizationUrl(HttpServletRequest request, String accessKeyId, String secretAccessKey) throws Exception {        String requestDate = request.getParameter("X-Amz-Date");        String contentHash = "UNSIGNED-PAYLOAD";        String httpMethod = request.getMethod();        String uri = request.getRequestURI().split("\\?")[0];        String queryString = ConvertOp.convert2String(request.getQueryString());        //示例        //"http://localhost:8001/s3/kkk/%E6%B1%9F%E5%AE%81%E8%B4%A2%E6%94%BF%E5%B1%80%E9%A1%B9%E7%9B%AE%E5%AF%B9%E6%8E%A5%E6%96%87%E6%A1%A3.docx?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20230531T024715Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=admin%2F20230531%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=038e2ea71073761aa0370215621599649e9228177c332a0a79f784b1a6d9ee39        ///region 参数筹备        //第一局部-凭证范畴        String credential =request.getParameter("X-Amz-Credential");        String[] credentials = credential.split("\\/");        String accessKey = credentials[0];        if (!accessKeyId.equals(accessKey)) {            return false;        }        String date = credentials[1];        String region = credentials[2];        String service = credentials[3];        String aws4Request = credentials[4];        //第二局部-签名头中蕴含哪些字段        String signedHeader = request.getParameter("X-Amz-SignedHeaders");        String[] signedHeaders = signedHeader.split("\\;");        //第三局部-生成的签名        String signature = request.getParameter("X-Amz-Signature");        ///endregion        ///region 验证expire        String expires = request.getParameter("X-Amz-Expires");        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss'Z'");        LocalDateTime startDate = LocalDateTime.parse(requestDate,formatter);        ZoneId zoneId = ZoneId.systemDefault();        ZonedDateTime localDateTime = startDate.atZone(ZoneId.of("UTC")).withZoneSameInstant(zoneId);        startDate = localDateTime.toLocalDateTime();        LocalDateTime endDate = startDate.plusSeconds(ConvertOp.convert2Int(expires));        if(endDate.isBefore(LocalDateTime.now())){            return false;        }        ///endregion        ///region 待签名字符串        String stringToSign = "";        //签名由4局部组成        //1-Algorithm – 用于创立标准申请的哈希的算法。对于 SHA-256，算法是 AWS4-HMAC-SHA256。        stringToSign += "AWS4-HMAC-SHA256" + "\n";        //2-RequestDateTime – 在凭证范畴内应用的日期和工夫。        stringToSign += requestDate + "\n";        //3-CredentialScope – 凭证范畴。这会将生成的签名限度在指定的区域和服务范畴内。该字符串采纳以下格局：YYYYMMDD/region/service/aws4_request        stringToSign += date + "/" + region + "/" + service + "/" + aws4Request + "\n";        //4-HashedCanonicalRequest – 标准申请的哈希。        //<HTTPMethod>\n        //<CanonicalURI>\n        //<CanonicalQueryString>\n        //<CanonicalHeaders>\n        //<SignedHeaders>\n        //<HashedPayload>        String hashedCanonicalRequest = "";        //4.1-HTTP Method        hashedCanonicalRequest += httpMethod + "\n";        //4.2-Canonical URI        hashedCanonicalRequest += uri + "\n";        //4.3-Canonical Query String        if(!StringUtil.isEmpty(queryString)){            Map<String, String> queryStringMap =  parseQueryParams(queryString);            List<String> keyList = new ArrayList<>(queryStringMap.keySet());            Collections.sort(keyList);            StringBuilder queryStringBuilder = new StringBuilder("");            for (String key:keyList) {                if(!key.equals("X-Amz-Signature")){                    queryStringBuilder.append(key).append("=").append(queryStringMap.get(key)).append("&");                }            }            queryStringBuilder.deleteCharAt(queryStringBuilder.lastIndexOf("&"));            hashedCanonicalRequest += queryStringBuilder.toString() + "\n";        }else{            hashedCanonicalRequest += queryString + "\n";        }        //4.4-Canonical Headers        for (String name : signedHeaders) {            hashedCanonicalRequest += name + ":" + request.getHeader(name) + "\n";        }        hashedCanonicalRequest += "\n";        //4.5-Signed Headers        hashedCanonicalRequest += signedHeader + "\n";        //4.6-Hashed Payload        hashedCanonicalRequest += contentHash;        stringToSign += doHex(hashedCanonicalRequest);        ///endregion        ///region 从新生成签名        //计算签名的key        byte[] kSecret = ("AWS4" + secretAccessKey).getBytes("UTF8");        byte[] kDate = doHmacSHA256(kSecret, date);        byte[] kRegion = doHmacSHA256(kDate, region);        byte[] kService = doHmacSHA256(kRegion, service);        byte[] signatureKey = doHmacSHA256(kService, aws4Request);        //计算签名        byte[] authSignature = doHmacSHA256(signatureKey, stringToSign);        //对签名编码解决        String strHexSignature = doBytesToHex(authSignature);        ///endregion        if (signature.equals(strHexSignature)) {            return true;        }        return false;    }    private String doHex(String data) {        MessageDigest messageDigest;        try {            messageDigest = MessageDigest.getInstance("SHA-256");            messageDigest.update(data.getBytes("UTF-8"));            byte[] digest = messageDigest.digest();            return String.format("%064x", new java.math.BigInteger(1, digest));        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {            e.printStackTrace();        }        return null;    }    private byte[] doHmacSHA256(byte[] key, String data) throws Exception {        String algorithm = "HmacSHA256";        Mac mac = Mac.getInstance(algorithm);        mac.init(new SecretKeySpec(key, algorithm));        return mac.doFinal(data.getBytes("UTF8"));    }    final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();    private String doBytesToHex(byte[] bytes) {        char[] hexChars = new char[bytes.length * 2];        for (int j = 0; j < bytes.length; j++) {            int v = bytes[j] & 0xFF;            hexChars[j * 2] = hexArray[v >>> 4];            hexChars[j * 2 + 1] = hexArray[v & 0x0F];        }        return new String(hexChars).toLowerCase();    }    public static Map<String, String> parseQueryParams(String queryString) {        Map<String, String> queryParams = new HashMap<>();        try {            if (queryString != null && !queryString.isEmpty()) {                String[] queryParamsArray = queryString.split("\\&");                for (String param : queryParamsArray) {                    String[] keyValue = param.split("\\=");                    if (keyValue.length == 1) {                        String key = keyValue[0];                        String value = "";                        queryParams.put(key, value);                    }                    else if (keyValue.length == 2) {                        String key = keyValue[0];                        String value = keyValue[1];                        queryParams.put(key, value);                    }                }            }        } catch (Exception e) {            e.printStackTrace();        }        return queryParams;    }}