PAYOK Signature Generator

Yaak plugin to generate PAYOK RSA-SHA256 digital signatures directly inside your requests.

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Template Functions

payok.signature

Generates the sign header value. The plugin reads the request body automatically — no need to copy it into the arguments.

Setup:

1. In the Headers tab, add a header named sign
2. In the value field, type payok and select payok.signature from autocomplete
3. Fill in the dialog:
   • Endpoint Path — e.g. /api-pay/payment/V3.2/order/create-api
   • Private Key — your PKCS#8 RSA private key in Base64, or an environment variable reference
4. Click Save

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payok.timestamp

Generates the current ISO8601 timestamp (e.g. 2024-01-15T10:30:00.123Z).

In the request body, place your cursor inside the requestTime value and select payok.timestamp from the template tag autocomplete.

{ "requestTime": "${[ payok.timestamp() ]}" }

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payok.uuid

Generates a UUID for fields like merchantOrderId that must be unique per request.

{ "merchantOrderId": "${[ payok.uuid() ]}" }

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How caching works

payok.signature expires both caches before rendering the body. This guarantees:

1. Uniqueness — each request send gets a fresh UUID and timestamp, even when requests are sent in rapid succession.
2. Consistency — the body used to compute the signature is identical to the body sent in the request.

payok.signature renders
  → expires UUID + timestamp caches
  → renders body → payok.uuid() and payok.timestamp() generate fresh values and cache them
  → signs body with those values

Yaak sends actual request
  → renders body → payok.uuid() and payok.timestamp() return cached values  ✓

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Private Key Formats

Both formats are accepted:

MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSj...

-----BEGIN PRIVATE KEY-----
MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSj...
-----END PRIVATE KEY-----

If your key starts with -----BEGIN RSA PRIVATE KEY----- (PKCS#1), convert it first:

openssl pkcs8 -topk8 -nocrypt -in rsa_private.pem -out pkcs8_private.pem

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Signing Algorithm

message   = <request_body_string> + "&" + <endpoint_path>
signature = Base64( RSA-SHA256-sign(privateKey, message) )