(Perl) ebay: Add Digital Signature to HTTP Request

See more eBay Examples

Demonstrates how to add a digital signature to an ebay HTTP request.

For more information, see https://developer.ebay.com/develop/guides/digital-signatures-for-apis

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# Note: Ebay provides a Key Management API
# See https://developer.ebay.com/api-docs/developer/key-management/overview.html

# The following test keys can be used: 
# 
# Ed25519 
# 
# Private Key:
# 
# -----BEGIN PRIVATE KEY-----
# MC4CAQAwBQYDK2VwBCIEIJ+DYvh6SEqVTm50DFtMDoQikTmiCqirVv9mWG9qfSnF
# -----END PRIVATE KEY-----

$strPrivateKey = "MC4CAQAwBQYDK2VwBCIEIJ+DYvh6SEqVTm50DFtMDoQikTmiCqirVv9mWG9qfSnF";

# 
# Public Key:
# 
# -----BEGIN PUBLIC KEY-----
# MCowBQYDK2VwAyEAJrQLj5P/89iXES9+vFgrIy29clF9CC/oPPsw3c5D0bs=
# -----END PUBLIC KEY-----

$strPublicKey = "MCowBQYDK2VwAyEAJrQLj5P/89iXES9+vFgrIy29clF9CC/oPPsw3c5D0bs=";

# This example assumes you got a JWE for your given private key from the Ebay Key Management REST API.
# This JWE is just for example:
$strJwe = "eyJ6aXAiOiJERUYiLCJlbmMiOiJBMjU2R0NNIiwidGFnIjoiSXh2dVRMb0FLS0hlS0Zoa3BxQ05CUSIsImFsZyI6IkEyNTZHQ01LVyIsIml2IjoiaFd3YjNoczk2QzEyOTNucCJ9.2o02pR9SoTF4g_5qRXZm6tF4H52TarilIAKxoVUqjd8.3qaF0KJN-rFHHm_P.AMUAe9PPduew09mANIZ-O_68CCuv6EIx096rm9WyLZnYz5N1WFDQ3jP0RBkbaOtQZHImMSPXIHVaB96RWshLuJsUgCKmTAwkPVCZv3zhLxZVxMXtPUuJ-ppVmPIv0NzznWCOU5Kvb9Xux7ZtnlvLXgwOFEix-BaWNomUAazbsrUCbrp514GIea3butbyxXLNi6R9TJUNh8V2uan-optT1MMyS7eMQnVGL5rYBULk.9K5ucUqAu0DqkkhgubsHHw";

$sbBody = chilkat::CkStringBuilder->new();
$sbBody->Append("{\"hello\": \"world\"}");

print "Body of request:" . "\r\n";
print $sbBody->getAsString() . "\r\n";

# -------------------------------------------------
# Build the signature base string...

$sbSigBase = chilkat::CkStringBuilder->new();

$sbSigBase->Append("\"content-digest\": sha-256=:");
$sbSigBase->Append($sbBody->getHash("sha256","base64","utf-8"));
$sbSigBase->Append(":\n");

$sbSigBase->Append("\"x-ebay-signature-key\": ");
$sbSigBase->Append($strJwe);
$sbSigBase->Append("\n");

$sbSigBase->Append('\'@method\': POST\n');

# This is the path part of the URL without query params...
$sbSigBase->Append('\'@path\': ');
$sbSigBase->Append("/verifysignature");
$sbSigBase->Append("\n");

# The is the domain, such as "api.ebay.com" w/ port if the port is something unusual.
# In this example, we're testing against a local docker test server (see the info at https://developer.ebay.com/develop/guides/digital-signatures-for-apis)
# Normally, I think it would just be "api.ebay.com" instead of "localhost:8080".
$sbSigBase->Append('\'@authority\': ');
$sbSigBase->Append("localhost:8080");
$sbSigBase->Append("\n");

$sbSigBase->Append('\'@signature-params\': ');

$sbSigInput = chilkat::CkStringBuilder->new();
$sbSigInput->Append('(\'content-digest\' \'x-ebay-signature-key\' \'@method\' \'@path\' \'@authority\')');
$sbSigInput->Append(";created=");

$dt = chilkat::CkDateTime->new();
$dt->SetFromCurrentSystemTime();
$unixTimeNow = $dt->getAsUnixTimeStr(0);
$sbSigInput->Append($unixTimeNow);

$sbSigBase->AppendSb($sbSigInput);

# -------------------------------------------------
# Sign the signature base string using the Ed25519 private key

$bdPrivKey = chilkat::CkBinData->new();
$bdPrivKey->AppendEncoded($strPrivateKey,"base64");

$privKey = chilkat::CkPrivateKey->new();
$success = $privKey->LoadAnyFormat($bdPrivKey,"");
if ($success == 0) {
    print $privKey->lastErrorText() . "\r\n";
    exit;
}

$bdToBeSigned = chilkat::CkBinData->new();
$bdToBeSigned->AppendSb($sbSigBase,"utf-8");

$eddsa = chilkat::CkEdDSA->new();
$sigBase64 = $eddsa->signBdENC($bdToBeSigned,"base64",$privKey);
if ($eddsa->get_LastMethodSuccess() == 0) {
    print $eddsa->lastErrorText() . "\r\n";
    exit;
}

print "sigBase64:" . "\r\n";
print $sigBase64 . "\r\n";

# ----------------------------------------------------------
# Send the JSON POST

$http = chilkat::CkHttp->new();

$http->SetRequestHeader("x-ebay-signature-key",$strJwe);

$sbContentDigestHdr = chilkat::CkStringBuilder->new();
$sbContentDigestHdr->Append("sha-256=:");
$sbContentDigestHdr->Append($sbBody->getHash("sha256","base64","utf-8"));
$sbContentDigestHdr->Append(":");
$http->SetRequestHeader("Content-Digest",$sbContentDigestHdr->getAsString());

$sbSigHdr = chilkat::CkStringBuilder->new();
$sbSigHdr->Append("sig1=:");
$sbSigHdr->Append($sigBase64);
$sbSigHdr->Append(":");
$http->SetRequestHeader("Signature",$sbSigHdr->getAsString());

$sbSigInput->Prepend("sig1=");
$http->SetRequestHeader("Signature-Input",$sbSigInput->getAsString());

# Add this header to make eBay actually check the signature.
$http->SetRequestHeader("x-ebay-enforce-signature","true");

# Set the OAuth2 access token to add the "Authorization: Bearer <access_token>" to the header.
$http->put_AuthToken("your_oauth2_access_token");

# The signature base string constructed above is valid if we send this POST to "http://localhost:8080/verifysignature"
# Normally, you'll send your POST to some api.ebay.com endpoint.
$url = "http://localhost:8080/verifysignature";

# resp is a HttpResponse
$resp = $http->PostJson2("http://localhost:8080/verifysignature","application/json",$sbBody->getAsString());
if ($http->get_LastMethodSuccess() == 0) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

print "Response status code: " . $resp->get_StatusCode() . "\r\n";
print "Response body:" . "\r\n";
print $resp->bodyStr() . "\r\n";