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Webhook Common Rules

For Security Purpose, Binance will add signature for webhook notification. Partner needs to verify the signature using the public key issued from Binance Pay.

Protocol Rules#

The following specifies the rules for calling the Webhook Notification from Binance payment.

RuleDescription
Transfer ModeUse HTTPS for secure transactions.
Submit ModePOST/GET, depends on the API.
Data FormatData submitted and response are both in application/json format.
Char EncodingUse UTF-8 character encoding.
Signature AlgorithmRSA, asymmetric cryptographic algorithm
Signature RequirementSignature-checking is required for requesting and receiving data.
Logic JudgmentDetermine protocol field, service field and transaction status.

Request Header#

AttributesTypeRequiredLimitationDescription
BinancePay-Certificate-SNlongY-MD5 hash value of public key
BinancePay-NoncestringYmust be 32 digitsA random string with 32 bytes, e.g. random ascii decimal within a-z and A-Z and loop 32 times to form a random string
BinancePay-TimestampstringY-time stamp in millis
BinancePay-SignaturestringY-signature, generated by Binance Pay

Verify the Signature#

Build the payload#

Java

String payload = timestamp + "\n" + nonce + "\n" + body + "\n";

PHP

$payload = $headers['Binancepay-Timestamp'] . "\n" . $headers['Binancepay-Nonce'] . "\n" . $entityBody . "\n";

Note:

  • โ€˜\nโ€™ is LF, ASCII value is '0x0A'

Decode the Signature with Base64#

Java

byte[] decodedSignature = Base64.getDecoder().decode(signature);

PHP

$decodedSignature = base64_decode ( $headers['Binancepay-Signature'] );

Verify the content with public key#

Note:

  • Hash algorithm should use SHA256

Sample Java code is here, together with org.bouncycastle toolkit.

 // input: pubKeyStr, decodedSignature, payload    PEMParser pubParser = new PEMParser(new StringReader(pubKeyStr))    SubjectPublicKeyInfo pubKeyObj = (SubjectPublicKeyInfo) pubParser.readObject();    AsymmetricKeyParameter pubKey = PublicKeyFactory.createKey(pubKeyObj);
    byte[] payloadBytes = payload.getBytes(StandardCharsets.UTF_8);    RSADigestSigner verifier = new RSADigestSigner(new SHA256Digest());    verifier.init(false, pubKey);    verifier.update(payloadBytes, 0, payloadBytes.length);
    return verifier.verifySignature(decodedSignature);

PHP

openssl_verify($payload, $decodedSignature, $publicKey, OPENSSL_ALGO_SHA256 );