apisix/doc/plugins/hmac-auth.md

• 中文

Summary

• Name
• Attributes
• How To Enable
• Test Plugin
• Disable Plugin

Name

hmac-auth is an authentication plugin that need to work with consumer. Add HMAC Authentication to a service or route.

The consumer then adds its key to request header to verify its request.

Attributes

Name	Type	Requirement	Default	Valid	Description
access_key	string	required			Different consumer objects should have different values, and it should be unique. If different consumers use the same access_key, a request matching exception will occur.
secret_key	string	required			Use as a pair with access_key.
algorithm	string	optional	"hmac-sha256"	["hmac-sha1", "hmac-sha256", "hmac-sha512"]	Encryption algorithm.
clock_skew	integer	optional	0		The clock skew allowed by the signature in seconds. For example, if the time is allowed to skew by 10 seconds, then it should be set to 10. especially, 0 means not checking Date
signed_headers	array[string]	optional			Restrict the headers that are added to the encrypted calculation. After the specified, the client request can only specify the headers within this range. When this item is empty, all the headers specified by the client request will be added to the encrypted calculation
keep_headers	boolean	optional	false	[ true, false ]	Whether it is necessary to keep the request headers of X-HMAC-SIGNATURE, X-HMAC-ALGORITHM and X-HMAC-SIGNED-HEADERS in the http request after successful authentication. true: means to keep the http request header, false: means to remove the http request header.

How To Enable

1. set a consumer and config the value of the hmac-auth option

curl http://127.0.0.1:9080/apisix/admin/consumers -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "username": "jack",
    "plugins": {
        "hmac-auth": {
            "access_key": "user-key",
            "secret_key": "my-secret-key",
            "clock_skew": 10,
            "signed_headers": ["User-Agent", "Accept-Language", "x-custom-a"]
        }
    }
}'

2. add a Route or add a Service , and enable the hmac-auth plugin

curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "uri": "/index.html",
    "plugins": {
        "hmac-auth": {}
    },
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "39.97.63.215:80": 1
        }
    }
}'

Test Plugin

generate signature:

The calculation formula of the signature is signature = HMAC-SHAx-HEX(secret_key, signing_string). From the formula, it can be seen that in order to obtain the signature, two parameters, SECRET_KEY and signing_STRING, are required. Where secret_key is configured by the corresponding consumer, the calculation formula of signing_STRING is signing_string = signing_string = HTTP Method + \n + HTTP URI + \n + canonical_query_string + \n + access_key + \n + Date + \n + signed_headers_string.

1. HTTP Method : Refers to the GET, PUT, POST and other request methods defined in the HTTP protocol, and must be in all uppercase.
2. HTTP URI : HTTP URI requirements must start with "/", those that do not start with "/" need to be added, and the empty path is "/".
3. Date : Date in http header(GMT format).
4. canonical_query_string :canonical_query_string is the result of encoding the query in the URL (query is the string "key1 = valve1 & key2 = valve2" after the "?" in the URL).
5. signed_headers_string :signed_headers_string is the result of obtaining the fields specified by the client from the request header and concatenating the strings in order.

The coding steps are as follows:

• Extract the query item in the URL, that is, the string "key1 = valve1 & key2 = valve2" after the "?" in the URL.
• Split the query into several items according to the & separator, each item is in the form of key=value or only key.
• Encoding each item after disassembly is divided into the following two situations.
  • When the item has only key, the conversion formula is UriEncode(key) + "=".
  • When the item is in the form of key=value, the conversion formula is in the form of UriEncode(key) + "=" + UriEncode(value). Here value can be an empty string.
  • After converting each item, sort by key in lexicographic order (ASCII code from small to large), and connect them with the & symbol to generate the corresponding canonical_query_string.

The signed_headers_string generation steps are as follows:

• Obtain the headers specified to be added to the calculation from the request header. For details, please refer to the placement of SIGNED_HEADERS in the next section Use the generated signature to make a request attempt.
• Take out the headers specified by SIGNED_HEADERS in order from the request header, and splice them together in order of name:value. After splicing, a signed_headers_string is generated.

HeaderKey1 + ":" + HeaderValue1 + "\n"\+
HeaderKey2 + ":" + HeaderValue2 + "\n"\+
...
HeaderKeyN + ":" + HeaderValueN

Here is a full example：

GET
/hello
your-access-key
Mon, 28 Sep 2020 06:48:57 GMT
x-custom-header:value

Use the generated signature to try the request

Note: ACCESS_KEY, SIGNATURE, ALGORITHM, DATE, SIGNED_HEADERS respectively represent the corresponding variables Note: SIGNED_HEADERS is the headers specified by the client to join the encryption calculation

• The signature information is put together in the request header Authorization field:

$ curl http://127.0.0.1:9080/index.html -H 'Authorization: hmac-auth-v1# + ACCESS_KEY + # + base64_encode(SIGNATURE) + # + ALGORITHM + # + DATE + # + SIGNED_HEADERS' -i
HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 13175
...
Accept-Ranges: bytes

<!DOCTYPE html>
<html lang="cn">
...

• The signature information is separately placed in the request header:

$ curl http://127.0.0.1:9080/index.html -H 'X-HMAC-SIGNATURE: base64_encode(SIGNATURE)' -H 'X-HMAC-ALGORITHM: ALGORITHM' -H 'Date: DATE' -H 'X-HMAC-ACCESS-KEY: ACCESS_KEY' -H 'X-HMAC-SIGNED-HEADERS: SIGNED_HEADERS' -i
HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 13175
...
Accept-Ranges: bytes

<!DOCTYPE html>
<html lang="cn">

Custom header key

We can customize header key for auth parameters by adding the attribute configuration of the plugin under plugin_attr in conf / config.yaml.

plugin_attr:
  hmac-auth:
    signature_key: X-APISIX-HMAC-SIGNATURE
    algorithm_key: X-APISIX-HMAC-ALGORITHM
    date_key: X-APISIX-DATE
    access_key: X-APISIX-HMAC-ACCESS-KEY
    signed_headers_key: X-APISIX-HMAC-SIGNED-HEADERS

After customizing the header, request example:

$ curl http://127.0.0.1:9080/index.html -H 'X-APISIX-HMAC-SIGNATURE: base64_encode(SIGNATURE)' -H 'X-APISIX-HMAC-ALGORITHM: ALGORITHM' -H 'X-APISIX-DATE: DATE' -H 'X-APISIX-HMAC-ACCESS-KEY: ACCESS_KEY' -H 'X-APISIX-HMAC-SIGNED-HEADERS: SIGNED_HEADERS' -i
HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 13175
...
Accept-Ranges: bytes

<!DOCTYPE html>
<html lang="cn">

Disable Plugin

When you want to disable the hmac-auth plugin, it is very simple, you can delete the corresponding json configuration in the plugin configuration, no need to restart the service, it will take effect immediately:

$ curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
    "uri": "/index.html",
    "plugins": {},
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "39.97.63.215:80": 1
        }
    }
}'