in Notation.Plugin.AzureKeyVault/Command/GenerateSignature.cs [44:115]
public async Task<IPluginResponse> RunAsync()
{
// Obtain the certificate chain
var certChain = new X509Certificate2Collection();
X509Certificate2 leafCert;
string? certBundlePath = _request.PluginConfig?.GetValueOrDefault("ca_certs", "");
if (_request.PluginConfig?.GetValueOrDefault("self_signed")?.ToLower() == "true")
{
if (!string.IsNullOrEmpty(certBundlePath))
{
throw new PluginException("Self-signed certificate is specified. Please do not specify the `ca_certs` parameter if it is a self-signed certificate.");
}
// Obtain self-signed leaf certificate from Azure Key Vault
leafCert = await _keyVaultClient.GetCertificateAsync();
certChain.Add(leafCert);
}
else
{
if (string.IsNullOrEmpty(certBundlePath))
{
// Obtain the certificate chain from Azure Key Vault using
// GetSecret permission. Ensure intermediate and root
// certificates are merged into the Key Vault certificate to
// retrieve the full chain.
// reference: https://learn.microsoft.com//azure/key-vault/certificates/create-certificate-signing-request
X509Certificate2Collection? certificateChain;
try
{
certificateChain = await _keyVaultClient.GetCertificateChainAsync();
}
catch (Azure.RequestFailedException ex)
{
if (ex.Message.Contains("does not have secrets get permission"))
{
throw new PluginException("The plugin does not have secrets get permission. Please grant the permission to the credential associated with the plugin or specify the file path of the certificate chain bundle through the `ca_certs` parameter in the plugin config.");
}
throw;
}
// build the certificate chain
certChain = CertificateChain.Build(certificateChain);
leafCert = certChain.First();
}
else
{
// Obtain the certificate bundle from file
// (including the intermediate and root certificates).
var certBundle = CertificateBundle.Create(certBundlePath);
// obtain the leaf certificate from Azure Key Vault
leafCert = await _keyVaultClient.GetCertificateAsync();
// build the certificate chain
certChain.Add(leafCert);
certChain.AddRange(certBundle);
certChain = CertificateChain.Build(certChain);
}
}
// Extract KeySpec from the certificate
var keySpec = leafCert.KeySpec();
// Sign
var signature = await _keyVaultClient.SignAsync(keySpec.ToKeyVaultSignatureAlgorithm(), _request.Payload);
return new GenerateSignatureResponse(
keyId: _request.KeyId,
signature: signature,
signingAlgorithm: keySpec.ToSigningAlgorithm(),
certificateChain: certChain.Select(x => x.RawData).ToList());
}