Request Signing

Certain endpoints require secondary validation prior to the request being accepted for processing. We use Ed25519 based signatures to validate requests. These endpoints will specify the x-signature and x-timestamp headers as additional parameters.

Signing Keys

You will generate the signing key pair when onboarding. You are required to provide us the generated Ed25519 public key to complete onboarding.

You must use the associated Ed25519 signing key (private key) when creating signatures for requests.

Please note that signing keys (Ed25519 private keys) should be stored securely. The signing key should only be used to derive request signatures and should never be sent in a request. Layer2 will never request you share your private key.

Signatures are optional unless explicitly required, but are encouraged for all requests. If a signature is provided, it will be verified.

Generating the Signing Key

You must securely generate an Ed25519 key pair on your own hardware and retain both the public and private portions. Layer2 requires the 64-character (32 bytes) hex-encoded Ed25519 during onboarding.

Code Sample (Python) -

import nacl
import nacl.signing
import secrets

seed = secrets.token_bytes(32)

# Generate a new random signing key
signing_key = nacl.signing.SigningKey(seed)

# Obtain the hex-encoded signing key
print('Signing key:')

# Obtain the hex-encoded verify key for the given signing key
# Use this when onboarding with Layer2
print('Public key:')

Generating the Signing Key

To sign a request, generate a request signature using the Ed25519 private (signing) key you generated during onboarding, and provide it alongside the request in the x-signature header.Signing is a 3 step process (below), details of each field using in signing is explained below.

Step Action Description
1 Concatenate Concatenate the timestamp, method, request path, and body into a string. There are no spaces or other characters between these values. The order of the fields MUST follow the order stipulated here.
2 Sign Take the string from step 1 and generate a signature using your Ed25519 private key
3 Encode Take the signed value and hex-encode the output.

The fields used to generate the signature are as follows. If the conditions below are not met, your signature will not validate. | Field | Description | |---|---| | Timestamp | The number of seconds since the Unix Epoch in UTC, and must be within one minute of the API service's time when the. The same value MUST be also placed in the x-timestamp header. | | Method | Uppercase HTTP verb (GET, PUT, POST, DELETE) | | Request Path | Lowercase path minus the domain, including ALL query parameters and values (ex. /api/v1/accounts/payments/1001-1234/address?type=abc). | | Body | Should be omitted where there is no body (e.g. GET). The stringified HTTP request body. |

Signing Example

You can validate your signing code using the example below;

Field Value
Timestamp 1527380000
Method POST
Request Path /api/v1/accounts/payments/1001-1234/address?type=abc
Body {"amount": "100","paymentreference": "FUND01-00023423","payorid": "0000-0003"}
Signing Key 302e020100300506032b6570042204200df0ce421b0830759ea9bfa727c0f4d0aa7086cfaf26c66e7e85bd10787d5728
Public Key 302a300506032b657003210095de28d850d6be3525384323b5add134dcb9b3bb404f43cbf47dac5e11c351de
Signature Key 51b19da0a23377bbb72222ba78bc32f0ec24404ac24b1a0c8f6942f2eb9e26bd6ffb078b9630a376f45360b74861f29198a81d93c2ae09971969b19532a9a800
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