HMAC 身份验证 - REST API 参考

Artículo
02/05/2024

可以使用 HMAC-SHA256 身份验证方案对 HTTP 请求进行身份验证。（HMAC 是指基于哈希的消息身份验证代码。）必须通过 TLS 传输这些请求。

必备条件

凭据 - <访问密钥 ID>
机密 - base64 解码的访问密钥值。 base64_decode(<Access Key Value>)

凭据（也称为 id）和机密（也称为 value）的值必须从 Azure 应用配置的实例获取。可以使用 Azure 门户或 Azure CLI 执行此操作。

为每个请求提供身份验证所需的所有 HTTP 标头。至少需要以下标头：

请求标头	说明
主机	Internet 主机和端口号。有关详细信息，请参阅 3.2.2 部分。
日期	发出请求的日期和时间。它与当前的协调世界时（格林威治标准时间）相差不能超过 15 分钟。此值为 HTTP 日期，如 3.3.1 部分所述。
x-ms-date	与上述 `Date` 相同。当代理无法直接访问 `Date` 请求头或代理对其进行修改时，可以改用它。如果同时提供了 `x-ms-date` 和 `Date`，则 `x-ms-date` 优先。
x-ms-content-sha256	请求正文的 base64 编码的 SHA256 哈希。即使没有正文，也必须提供它。 `base64_encode(SHA256(body))`
授权	HMAC-SHA256 方案所需的身份验证信息。本文的后面部分会介绍格式和详细信息。

示例：

Host: {myconfig}.azconfig.io
Date: Fri, 11 May 2018 18:48:36 GMT
x-ms-content-sha256: {SHA256 hash of the request body}
Authorization: HMAC-SHA256 Credential={Access Key ID}&SignedHeaders=x-ms-date;host;x-ms-content-sha256&Signature={Signature}

授权标头

语法

Authorization：HMAC-SHA256Credential=<value>&SignedHeaders=<value>&Signature=<value>

参数	描述
HMAC-SHA256	授权方案。（必需）
凭据	用于计算签名的访问密钥的 ID。（必需）
SignedHeaders	添加到签名的 HTTP 请求头。（必需）
Signature	String-To-Sign 的 base64 编码的 HMACSHA256。（必需）

凭据

用于计算签名的访问密钥的 ID。

签名标头

为请求签名所需的 HTTP 请求头名称（以分号分隔）。这些 HTTP 标头必须与请求一起正确提供。请不要使用空格。

所需的 HTTP 请求标头

x-ms-date[或 Date];host;x-ms-content-sha256

任何其他 HTTP 请求标头也可添加到签名。只需将它们追加到 SignedHeaders 参数中即可。

示例：

x-ms-date;host;x-ms-content-sha256;Content-Type;Accept

签名

String-To-Sign 的 Base64 编码的 HMACSHA256 哈希。它使用由 Credential 标识的访问密钥。 base64_encode(HMACSHA256(String-To-Sign, Secret))

String-To-Sign

它是请求的规范表示形式：

String-To-Sign=

HTTP_METHOD + '\n' + path_and_query + '\n' + signed_headers_values

参数	描述
HTTP_METHOD	与请求一起使用的大写 HTTP 方法名称。有关详细信息，请参阅第 9 部分。
path_and_query	串联在一起的请求绝对 URI 路径和查询字符串。有关详细信息，请参阅 3.3 部分。
signed_headers_values	`SignedHeaders` 中列出的所有 HTTP 请求头的值（以分号分隔）。该格式遵循 `SignedHeaders` 语义。

示例：

string-To-Sign=
            "GET" + '\n' +                                                                                  // VERB
            "/kv?fields=*&api-version=1.0" + '\n' +                                                         // path_and_query
            "Fri, 11 May 2018 18:48:36 GMT;{myconfig}.azconfig.io;{value of ms-content-sha256 header}"      // signed_headers_values

错误

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256, Bearer

原因： 未提供使用 HMAC-SHA256 方案的 Authorization 请求头。

解决方案： 提供有效的 Authorization HTTP 请求头。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="The access token has expired", Bearer

原因：Date 或 x-ms-date 请求头与当前的协调世界时（格林威治标准时间）相差超过 15 分钟。

解决方案： 提供正确的日期和时间。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="Invalid access token date", Bearer

原因：Date 或 x-ms-date 请求头缺失或无效。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="[Credential][SignedHeaders][Signature] is required", Bearer

原因：Authorization 请求头缺少所需的参数。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="Invalid Credential", Bearer

原因： 找不到所提供的 [Host]/[访问密钥 ID]。

解决方案： 检查 Authorization 请求头的 Credential 参数。请确保它是有效的访问密钥 ID，并确保 Host 标头指向已注册的帐户。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="Invalid Signature", Bearer

原因：提供的 Signature 与服务器需要的内容不匹配。

解决方案： 请确保 String-To-Sign 正确无误。请确保 Secret 正确无误且其使用方式正确（在使用之前已进行 base64 解码）。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="Signed request header 'xxx' is not provided", Bearer

原因：Authorization 标头中缺少 SignedHeaders 参数所需的请求头。

解决方案： 提供具有正确值的所需标头。

HTTP/1.1 401 Unauthorized
WWW-Authenticate: HMAC-SHA256 error="invalid_token" error_description="XXX is required as a signed header", Bearer

原因：SignedHeaders 中缺少参数。

解决方案： 查看“签名标头”最低要求。

代码片段

JavaScript

先决条件：Crypto-JS

function signRequest(host,
                     method,      // GET, PUT, POST, DELETE
                     url,         // path+query
                     body,        // request body (undefined of none)
                     credential,  // access key id
                     secret)      // access key value (base64 encoded)
{
        var verb = method.toUpperCase();
        var utcNow = new Date().toUTCString();
        var contentHash = CryptoJS.SHA256(body).toString(CryptoJS.enc.Base64);

        //
        // SignedHeaders
        var signedHeaders = "x-ms-date;host;x-ms-content-sha256"; // Semicolon separated header names

        //
        // String-To-Sign
        var stringToSign =
            verb + '\n' +                              // VERB
            url + '\n' +                               // path_and_query
            utcNow + ';' + host + ';' + contentHash;   // Semicolon separated SignedHeaders values

        //
        // Signature
        var signature = CryptoJS.HmacSHA256(stringToSign, CryptoJS.enc.Base64.parse(secret)).toString(CryptoJS.enc.Base64);

        //
        // Result request headers
        return [
            { name: "x-ms-date", value: utcNow },
            { name: "x-ms-content-sha256", value: contentHash },
            { name: "Authorization", value: "HMAC-SHA256 Credential=" + credential + "&SignedHeaders=" + signedHeaders + "&Signature=" + signature }
        ];
}

C#

using (var client = new HttpClient())
{
    var request = new HttpRequestMessage()
    {
        RequestUri = new Uri("https://{config store name}.azconfig.io/kv?api-version=1.0"),
        Method = HttpMethod.Get
    };

    //
    // Sign the request
    request.Sign(<Credential>, <Secret>);

    await client.SendAsync(request);
}

static class HttpRequestMessageExtensions
{
    public static HttpRequestMessage Sign(this HttpRequestMessage request, string credential, string secret)
    {
        string host = request.RequestUri.Authority;
        string verb = request.Method.ToString().ToUpper();
        DateTimeOffset utcNow = DateTimeOffset.UtcNow;
        string contentHash = Convert.ToBase64String(request.Content.ComputeSha256Hash());

        //
        // SignedHeaders
        string signedHeaders = "date;host;x-ms-content-sha256"; // Semicolon separated header names

        //
        // String-To-Sign
        var stringToSign = $"{verb}\n{request.RequestUri.PathAndQuery}\n{utcNow.ToString("r")};{host};{contentHash}";

        //
        // Signature
        string signature;

        using (var hmac = new HMACSHA256(Convert.FromBase64String(secret)))
        {
            signature = Convert.ToBase64String(hmac.ComputeHash(Encoding.ASCII.GetBytes(stringToSign)));
        }

        //
        // Add headers
        request.Headers.Date = utcNow;
        request.Headers.Add("x-ms-content-sha256", contentHash);
        request.Headers.Authorization = new AuthenticationHeaderValue("HMAC-SHA256", $"Credential={credential}&SignedHeaders={signedHeaders}&Signature={signature}");

        return request;
    }
}

static class HttpContentExtensions
{
    public static byte[] ComputeSha256Hash(this HttpContent content)
    {
        using (var stream = new MemoryStream())
        {
            if (content != null)
            {
                content.CopyToAsync(stream).Wait();
                stream.Seek(0, SeekOrigin.Begin);
            }

            using (var alg = SHA256.Create())
            {
                return alg.ComputeHash(stream.ToArray());
            }
        }
    }
}

Java

public CloseableHttpResponse signRequest(HttpUriRequest request, String credential, String secret)
        throws IOException, URISyntaxException {
    Map<String, String> authHeaders = generateHeader(request, credential, secret);
    authHeaders.forEach(request::setHeader);

    return httpClient.execute(request);
}

private static Map<String, String> generateHeader(HttpUriRequest request, String credential, String secret)
        throws URISyntaxException, IOException {
    String requestTime = GMT_DATE_FORMAT.format(new Date());

    String contentHash = buildContentHash(request);
    // SignedHeaders
    String signedHeaders = "x-ms-date;host;x-ms-content-sha256";

    // Signature
    String methodName = request.getRequestLine().getMethod().toUpperCase();
    URIBuilder uri = new URIBuilder(request.getRequestLine().getUri());
    String scheme = uri.getScheme() + "://";
    String requestPath = uri.toString().substring(scheme.length()).substring(uri.getHost().length());
    String host = new URIBuilder(request.getRequestLine().getUri()).getHost();
    String toSign = String.format("%s\n%s\n%s;%s;%s", methodName, requestPath, requestTime, host, contentHash);

    byte[] decodedKey = Base64.getDecoder().decode(secret);
    String signature = Base64.getEncoder().encodeToString(new HmacUtils(HMAC_SHA_256, decodedKey).hmac(toSign));

    // Compose headers
    Map<String, String> headers = new HashMap<>();
    headers.put("x-ms-date", requestTime);
    headers.put("x-ms-content-sha256", contentHash);

    String authorization = String.format("HMAC-SHA256 Credential=%s, SignedHeaders=%s, Signature=%s",
            credential, signedHeaders, signature);
    headers.put("Authorization", authorization);

    return headers;
}

private static String buildContentHash(HttpUriRequest request) throws IOException {
    String content = "";
    if (request instanceof HttpEntityEnclosingRequest) {
        try {
            StringWriter writer = new StringWriter();
            IOUtils.copy(((HttpEntityEnclosingRequest) request).getEntity().getContent(), writer,
                    StandardCharsets.UTF_8);

            content = writer.toString();
        }
        finally {
            ((HttpEntityEnclosingRequest) request).getEntity().getContent().close();
        }
    }

    byte[] digest = new DigestUtils(SHA_256).digest(content);
    return Base64.getEncoder().encodeToString(digest);
}

Golang

import (
    "bytes"
    "crypto/hmac"
    "crypto/sha256"
    "encoding/base64"
    "io/ioutil"
    "net/http"
    "strings"
    "time"
)

//SignRequest Setup the auth header for accessing Azure App Configuration service
func SignRequest(id string, secret string, req *http.Request) error {
    method := req.Method
    host := req.URL.Host
    pathAndQuery := req.URL.Path
    if req.URL.RawQuery != "" {
        pathAndQuery = pathAndQuery + "?" + req.URL.RawQuery
    }

    content, err := ioutil.ReadAll(req.Body)
    if err != nil {
        return err
    }
    req.Body = ioutil.NopCloser(bytes.NewBuffer(content))

    key, err := base64.StdEncoding.DecodeString(secret)
    if err != nil {
        return err
    }

    timestamp := time.Now().UTC().Format(http.TimeFormat)
    contentHash := getContentHashBase64(content)
    stringToSign := fmt.Sprintf("%s\n%s\n%s;%s;%s", strings.ToUpper(method), pathAndQuery, timestamp, host, contentHash)
    signature := getHmac(stringToSign, key)

    req.Header.Set("x-ms-content-sha256", contentHash)
    req.Header.Set("x-ms-date", timestamp)
    req.Header.Set("Authorization", "HMAC-SHA256 Credential="+id+", SignedHeaders=x-ms-date;host;x-ms-content-sha256, Signature="+signature)

    return nil
}

func getContentHashBase64(content []byte) string {
    hasher := sha256.New()
    hasher.Write(content)
    return base64.StdEncoding.EncodeToString(hasher.Sum(nil))
}

func getHmac(content string, key []byte) string {
    hmac := hmac.New(sha256.New, key)
    hmac.Write([]byte(content))
    return base64.StdEncoding.EncodeToString(hmac.Sum(nil))
}

Python


import base64
import hashlib
import hmac
from datetime import datetime
import six

def sign_request(host,
                method,     # GET, PUT, POST, DELETE
                url,        # Path + Query
                body,       # Request body
                credential, # Access Key ID
                secret):    # Access Key Value
    verb = method.upper()

    utc_now = str(datetime.utcnow().strftime("%a, %d %b %Y %H:%M:%S ")) + "GMT"

    if six.PY2:
        content_digest = hashlib.sha256(bytes(body)).digest()
    else:
        content_digest = hashlib.sha256(bytes(body, 'utf-8')).digest()

    content_hash = base64.b64encode(content_digest).decode('utf-8')

    # Signed Headers
    signed_headers = "x-ms-date;host;x-ms-content-sha256"  # Semicolon separated header names

    # String-To-Sign
    string_to_sign = verb + '\n' + \
                    url + '\n' + \
                    utc_now + ';' + host + ';' + content_hash  # Semicolon separated SignedHeaders values

    # Decode secret
    if six.PY2:
        decoded_secret = base64.b64decode(secret)
        digest = hmac.new(decoded_secret, bytes(
            string_to_sign), hashlib.sha256).digest()
    else:
        decoded_secret = base64.b64decode(secret, validate=True)
        digest = hmac.new(decoded_secret, bytes(
            string_to_sign, 'utf-8'), hashlib.sha256).digest()

    # Signature
    signature = base64.b64encode(digest).decode('utf-8')

    # Result request headers
    return {
        "x-ms-date": utc_now,
        "x-ms-content-sha256": content_hash,
        "Authorization": "HMAC-SHA256 Credential=" + credential + "&SignedHeaders=" + signed_headers + "&Signature=" + signature
    }

PowerShell

function Sign-Request(
    [string] $hostname,
    [string] $method,      # GET, PUT, POST, DELETE
    [string] $url,         # path+query
    [string] $body,        # request body
    [string] $credential,  # access key id
    [string] $secret       # access key value (base64 encoded)
)
{  
    $verb = $method.ToUpperInvariant()
    $utcNow = (Get-Date).ToUniversalTime().ToString("R", [Globalization.DateTimeFormatInfo]::InvariantInfo)
    $contentHash = Compute-SHA256Hash $body

    $signedHeaders = "x-ms-date;host;x-ms-content-sha256";  # Semicolon separated header names

    $stringToSign = $verb + "`n" +
                    $url + "`n" +
                    $utcNow + ";" + $hostname + ";" + $contentHash  # Semicolon separated signedHeaders values

    $signature = Compute-HMACSHA256Hash $secret $stringToSign

    # Return request headers
    return @{
        "x-ms-date" = $utcNow;
        "x-ms-content-sha256" = $contentHash;
        "Authorization" = "HMAC-SHA256 Credential=" + $credential + "&SignedHeaders=" + $signedHeaders + "&Signature=" + $signature
    }
}

function Compute-SHA256Hash(
    [string] $content
)
{
    $sha256 = [System.Security.Cryptography.SHA256]::Create()
    try {
        return [Convert]::ToBase64String($sha256.ComputeHash([Text.Encoding]::ASCII.GetBytes($content)))
    }
    finally {
        $sha256.Dispose()
    }
}

function Compute-HMACSHA256Hash(
    [string] $secret,      # base64 encoded
    [string] $content
)
{
    $hmac = [System.Security.Cryptography.HMACSHA256]::new([Convert]::FromBase64String($secret))
    try {
        return [Convert]::ToBase64String($hmac.ComputeHash([Text.Encoding]::ASCII.GetBytes($content)))
    }
    finally {
        $hmac.Dispose()
    }
}

# Stop if any error occurs
$ErrorActionPreference = "Stop"

$uri = [System.Uri]::new("https://{myconfig}.azconfig.io/kv?api-version=1.0")
$method = "GET"
$body = $null
$credential = "<Credential>"
$secret = "<Secret>"

$headers = Sign-Request $uri.Authority $method $uri.PathAndQuery $body $credential $secret
Invoke-RestMethod -Uri $uri -Method $method -Headers $headers -Body $body

Bash

先决条件：

先决条件	命令	经过测试的版本
Bash	bash	3.5.27、4.4.23
coreutils	tr	8.28
curl	curl	7.55.1、7.58.0
OpenSSL	openssl	1.1.0g、1.1.1a
util-linux	hexdump	2.14.1、2.31.1

#!/bin/bash

sign_request () {
    local host="$1"
    local method="$2"      # GET, PUT, POST, DELETE
    local url="$3"         # path+query
    local body="$4"        # request body
    local credential="$5"  # access key id
    local secret="$6"      # access key value (base64 encoded)

    local verb=$(printf "$method" | tr '[:lower:]' '[:upper:]')
    local utc_now="$(date -u '+%a, %d %b %Y %H:%M:%S GMT')"
    local content_hash="$(printf "$body" | openssl sha256 -binary | base64)"

    local signed_headers="x-ms-date;host;x-ms-content-sha256"  # Semicolon separated header names
    local string_to_sign="$verb\n$url\n$utc_now;$host;$content_hash"  # Semicolon separated signed_headers values

    local decoded_secret="$(printf "$secret" | base64 -d | hexdump -v -e '/1 "%02x"')"
    local signature="$(printf "$string_to_sign" | openssl sha256 -mac HMAC -macopt hexkey:"$decoded_secret" -binary | base64)"

    # Output request headers
    printf '%s\n' \
           "x-ms-date: $utc_now" \
           "x-ms-content-sha256: $content_hash" \
           "Authorization: HMAC-SHA256 Credential=$credential&SignedHeaders=$signed_headers&Signature=$signature"
}

host="{config store name}.azconfig.io"
method="GET"
url="/kv?api-version=1.0"
body=""
credential="<Credential>"
secret="<Secret>"

headers=$(sign_request "$host" "$method" "$url" "$body" "$credential" "$secret")

while IFS= read -r line; do
    header_args+=("-H$line")
done <<< "$headers"
curl -X "$method" -d "$body" "${header_args[@]}" "https://$host$url"

Compartir a través de

HMAC 身份验证 - REST API 参考

必备条件

授权标头

语法

凭据

签名标头

所需的 HTTP 请求标头

签名

String-To-Sign

错误

代码片段

JavaScript

C#

Java

Golang

Python

PowerShell

Bash

Recursos adicionales