Microsoft Graph：如何在客户端凭据流中获取带有证书的访问令牌？（而不是使用 client_secret）

Question

目标

我想使用证书而不是 Microsoft Graph 的客户端密钥来验证我的守护程序应用程序，并希望了解成功验证所需的确切请求。

使用以下资源：

• https://learn.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow#second-case-access-token-request-with-a-certificate
• https://learn.microsoft.com/en-us/graph/auth-v2-service
• https://laurakokkarinen.com/authenticating-to-office-365-apis-with-a-certificate-step-by-step/
• https://winprotocoldoc.blob.core.windows.net/developmentwindowsarchives/MS-OAPX/%5BMS-OAPX%5D.pdf

您的应用程序的 Azure AD 配置是否存在错误？

所有 Azure AD 配置均已事先使用client-secret. 证书公钥也已提前上传：

请求与问题

我设法创建了这个请求（租户 ID、客户端 ID、证书只是虚拟的）

价值观：

grant_type: : urn:ietf:params:oauth:client-assertion-type:jwt-bearer
client_assertion_type: logon_cert
client_id: my-client-id-from-azure
scope: https://graph.microsoft.com/.default
client_assertionJWT 包含

• 标头：（x5t 包含上传证书中的 base64 编码证书 sha1 指纹，请参见上图）

  {
    "typ": "JWT",
    "x5t": "QUY4RjBERERGMDBBOURGRUQ0MzkzODRGQTYzMjhFQ0FBRDNBOEUzNw",
    "alg": "RS256"
  }
  

• 有效负载：

  {
    "iss": "my-client-id-from-azure",
    "sub": "my-client-id-from-azure",
    "scope": "https://graph.microsoft.com/.default",
    "aud": "https://login.microsoftonline.com/my-tenant-id/oauth2/v2.0/token",
    "iat": 1625591612,
    "nbf": 1625591612,
    "exp": 1625595212,
    "jti": "some-dynamically-generated-uuid"
  }
  

要求：

POST https://login.microsoftonline.com/my-tenant-id/oauth2/v2.0/token
Content-Type: application/x-www-form-urlencoded; charset=UTF-8

client_assertion_type=urn%3Aietf%3Aparams%3Aoauth%3Aclient-assertion-type%3Ajwt-bearer&client_assertion=eyJ0eXAiOiJKV1QiLCJ4NXQiOiJSRFUwTUVRd016RkdOakpGTUVOQk5UaEVPVFpGTXpBNFFrRkZNMFUzTmpFd01USkVPRFUwUWc9PSIsImFsZyI6IlJTMjU2In0.eyJpc3MiOiJteS1jbGllbnQtaWQtZnJvbS1henVyZSIsInNjb3BlIjoiaHR0cHM6Ly9ncmFwaC5taWNyb3NvZnQuY29tLy5kZWZhdWx0IiwiYXVkIjoiaHR0cHM6Ly9sb2dpbi5taWNyb3NvZnRvbmxpbmUuY29tL215LXRlbmFudC1pZC9vYXV0aDIvdjIuMC90b2tlbiIsImlhdCI6MTYyNTY2MDU3MywibmJmIjoxNjI1NjYwNTczLCJzdWIiOiJteS1jbGllbnQtaWQtZnJvbS1henVyZSIsImp0aSI6IjlhZTQwYTk2LTliMTgtNDRhOS1hOWM3LWE3NDZjMjA4OGUxMyIsImV4cCI6MTYyNTY2NDE3M30.pw81FeQirjIsnXGlLSLDG5Cz4rIdOuF54M8fPmDlubNs0-DoHpkj9OdrCXlCPDWvQLaYAs3mH9kcSP-Z4rf-NgaiCF-ECL-iA2xxvQ3n8JSDeaPPkLd6tMAKeMm5sEIcap7RJ8Fnt1kCflVAOIuYCh_zijJd9etQj-2wfbtiHnHtlpg6n0-4u7oj9wAx2naIU6J4dtgdIPypBTfwxyXtZWy0nkM8jde6Jr7CqVVlECdf7wyGwN1Jhwf6PeihKn8peQKaXzVnMmLpcCmjNENnTRM5PmhEQkCGOOR4hMJkdfCONWmOtSoRlndhCQypBQM-fzl_-sDviXNjAYKvrYTUM-kwZZBqKyzdekqMnxxwnaKmF1uGVnrSjad_AfW0A9Vg9UpaqGvsbe8Doq15I7KE46kzd4y3fDoibDQG-qaYL8LYKcrVUDkTw_PNfiyihlcaGjBvHVaMBsYhJJlNnohktO0OES0WO0iUlj_M0PuOF7JxYsPAQZM5uZGPTRCQhen_8khQ8z70C2YYz965kCROL9-WC53Ezbt1R0QjHR4UupV3CtQfZe_BkTG8vYu7SMWbxDEGZKb6cRsTCgzqmd6l3f6OGojQA_EAvFJpL0kw0d_tfYnY4ZkyLdcI3G3fMyhicm7qmkiq7ZRdnGL2uCl-tpxsoLD7UbvVPD3CS_LNAp4&client_id=my-client-id-from-azure&scope=https%3A%2F%2Fgraph.microsoft.com%2F.default&grant_type=client_credentials

回复：

我期待一个访问令牌，相反，我得到一个401 Unauthorized说明

{
  "error": "invalid_client",
  "error_description": "AADSTS700027: Client assertion contains an invalid signature. [Reason - The key was not found., Thumbprint of key used by client: 'some-other-thumbprint', Please visit the Azure Portal, Graph Explorer or directly use MS Graph to see configured keys for app Id 'my-app-id'. Review the documentation at https://learn.microsoft.com/en-us/graph/deployments to determine the corresponding service endpoint and https://learn.microsoft.com/en-us/graph/api/application-get?view=graph-rest-1.0&tabs=http to build a query request URL, such as 'https://graph.microsoft.com/beta/applications/my-app-id']\r\nTrace ID: some-uuid\r\nCorrelation ID: some-other-uuid\r\nTimestamp: 2021-07-07 12:25:46Z",
  "error_codes": [
    700027
  ],
  "timestamp": "2021-07-06 12:25:46Z",
  "trace_id": "some-uuid",
  "correlation_id": "some-other-uuid",
  "error_uri": "https://login.microsoftonline.com/error?code=700027"
}

我不知道问题是什么。

问题：

我究竟做错了什么？

Answer 1

所以问题出在x5t标题的创建方式上。

hex我误解了在编码之前明确说明指纹是 a 的文档base64：

对于这样的指纹204C837E10143C1428D7911CB60ED0075C3E1062，字符串需要被视为十六进制二进制，而不是简单的字符串。

示例（PHP）：

伪代码：

// load certificate
certificate = load_file('/path/to/cert.pem')
// fingerprint is hex string 204C837E10143C1428D7911CB60ED0075C3E1062
certificate_fingerprint_hex_string = x509fingerprint($certificate)

// hexademical string is being converted to binary format
certificate_fingerprint_binary = hex_to_binary(certificate_fingerprint_hex_string)

// binary format gets base64 encoded (not base64url) to IEyDfhAUPBQo15Ectg7QB1w+EGI=
x5t = base64_encode(certificate_fingerprint_binary)

请求（文件）

Method和headers

POST https://login.microsoftonline.com/my-tenant-id/oauth2/v2.0/token
Content-Type: application/x-www-form-urlencoded; charset=UTF-8

正文（尚未根据 Content-Type 进行格式化）

• client_id：my-client-id-from-azure
• client_assertion_type：urn:ietf:params:oauth:client-assertion-type:jwt- bearer
• client_assertion：请参阅下面的JWT单击此处了解详细信息
• grant_type：client_credentials
• scope：https://graph.microsoft.com/.default

客户端断言

• 标头：（x5t包含上传证书中的 base64 编码证书 sha1 指纹，请参见上图）

  {
    "typ": "JWT",
    "x5t": "IEyDfhAUPBQo15Ectg7QB1w+EGI=",
    "alg": "RS256"
  }
  

• 有效负载：

  {
    "iss": "my-client-id-from-azure",
    "sub": "my-client-id-from-azure",
    "scope": "https://graph.microsoft.com/.default",
    "aud": "https://login.microsoftonline.com/my-tenant-id/oauth2/v2.0/token",
    "iat": 1625591612,
    "nbf": 1625591612,
    "exp": 1625595212,
    "jti": "some-dynamically-generated-uuid"
  }