> For the complete documentation index, see [llms.txt](https://help.santesuite.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.santesuite.org/developers/server-plugins/implementing-.net-features/service-definitions/data-signing-service.md).

# Data Signing Service

`IDataSigningService` in assembly SanteDB.Core.Api version 3.0.1980.0

## Summary

Contract for services which can sign data using configured digital signature algorithms

### Description

Implementers of this service contract are responsible for computing and validating digital signatures against arbitrary data streams. Implementers of this service are responsible for maintaining (or acquiring) a master list of keys which can be used for data signing, and validating digital signatures.

Implementers should also use the [IDataSigningCertificateManagerService](http://santesuite.org/assets/doc/net/html/T_SanteDB_Core_Security_Services_IDataSigningCertificateManagerService.htm) to support key identifiers which are indicated as a secure application/device identifier

## Operations

| Operation                 | Response/Return   | Input/Parameter                                                                                                                                      | Description                                               |
| ------------------------- | ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------- |
| GetNamedSignatureSettings | SignatureSettings | *String* **systemKeyId**                                                                                                                             | Get the siganture algorithm for the system configured key |
| GetSignatureSettings      | SignatureSettings | <p><em>Byte\[]</em> <strong>certificateThumbprint</strong><br><em>SignatureAlgorithm</em> <strong>signatureAlgorithm</strong></p>                    | Get the signature algorithm for the configured thumbprint |
| SignData                  | Byte\[]           | <p><em>Byte\[]</em> <strong>data</strong><br><em>String</em> <strong>systemKeyId</strong></p>                                                        | Sign with the configured system key                       |
| SignData                  | Byte\[]           | <p><em>Byte\[]</em> <strong>data</strong><br><em>SignatureSettings</em> <strong>settings</strong></p>                                                | Sign with the configured system key                       |
| Verify                    | Boolean           | <p><em>Byte\[]</em> <strong>data</strong><br><em>Byte\[]</em> <strong>signature</strong><br><em>String</em> <strong>systemKeyId</strong></p>         | Verifies the digital signature of the data                |
| Verify                    | Boolean           | <p><em>Byte\[]</em> <strong>data</strong><br><em>Byte\[]</em> <strong>signature</strong><br><em>SignatureSettings</em> <strong>settings</strong></p> | Verifies the digital signature of the data                |

## Implementations

### DefaultDataSigningService - (SanteDB.Core.Api)

Default data signing service

#### Description

This digital signature service uses the keys configured in the [SecurityConfigurationSection](http://santesuite.org/assets/doc/net/html/T_SanteDB_Core_Security_Configuration_SecurityConfigurationSection.htm) to sign data based on the type of signature algorithm in the [SecurityConfigurationSection](http://santesuite.org/assets/doc/net/html/T_SanteDB_Core_Security_Configuration_SecurityConfigurationSection.htm). Supported signature algorithms are:

* HMAC256 (HMAC + SHA256) using shared secrets
* RS256 (RSA+SHA256) using X.509 certificates (generation of a signature requires private key)
* RS512 (RSA+SHA512)

#### Service Registration

```markup
...
<section xsi:type="ApplicationServiceContextConfigurationSection" threadPoolSize="4">
	<serviceProviders>
		...
		<add type="SanteDB.Core.Security.DefaultDataSigningService, SanteDB.Core.Api, Version=3.0.1980.0, Culture=neutral, PublicKeyToken=null" />
		...
	</serviceProviders>
```

## Example Implementation

```csharp
/// Example Implementation
using SanteDB.Core.Security.Services;
/// Other usings here
public class MyDataSigningService : SanteDB.Core.Security.Services.IDataSigningService { 
	public String ServiceName => "My own IDataSigningService service";
	/// <summary>
	/// Get the siganture algorithm for the system configured key
	/// </summary>
	public SignatureSettings GetNamedSignatureSettings(String systemKeyId){
		throw new System.NotImplementedException();
	}
	/// <summary>
	/// Get the signature algorithm for the configured thumbprint
	/// </summary>
	public SignatureSettings GetSignatureSettings(Byte[] certificateThumbprint,SignatureAlgorithm signatureAlgorithm){
		throw new System.NotImplementedException();
	}
	/// <summary>
	/// Sign  with the configured system key
	/// </summary>
	public Byte[] SignData(Byte[] data,String systemKeyId){
		throw new System.NotImplementedException();
	}
	/// <summary>
	/// Sign  with the configured system key
	/// </summary>
	public Byte[] SignData(Byte[] data,SignatureSettings settings){
		throw new System.NotImplementedException();
	}
	/// <summary>
	/// Verifies the digital signature of the data
	/// </summary>
	public Boolean Verify(Byte[] data,Byte[] signature,String systemKeyId){
		throw new System.NotImplementedException();
	}
	/// <summary>
	/// Verifies the digital signature of the data
	/// </summary>
	public Boolean Verify(Byte[] data,Byte[] signature,SignatureSettings settings){
		throw new System.NotImplementedException();
	}
}
```

## References

* [IDataSigningService C# Documentation](http://santesuite.org/assets/doc/net/html/T_SanteDB_Core_Security_Services_IDataSigningService.htm)
* [DefaultDataSigningService C# Documentation](http://santesuite.org/assets/doc/net/html/T_SanteDB_Core_Security_DefaultDataSigningService.htm)