3rdPartyLibraries/iTechSharp/srcbc/cms/DefaultSignedAttributeTableGenerator.cs
2023-06-21 12:46:23 -04:00

105 lines
2.5 KiB
C#

using System;
using System.Collections;
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Cms;
namespace Org.BouncyCastle.Cms
{
/**
* Default signed attributes generator.
*/
public class DefaultSignedAttributeTableGenerator
: CmsAttributeTableGenerator
{
private readonly Hashtable table;
/**
* Initialise to use all defaults
*/
public DefaultSignedAttributeTableGenerator()
{
table = new Hashtable();
}
/**
* Initialise with some extra attributes or overrides.
*
* @param attributeTable initial attribute table to use.
*/
public DefaultSignedAttributeTableGenerator(
AttributeTable attributeTable)
{
if (attributeTable != null)
{
table = attributeTable.ToHashtable();
}
else
{
table = new Hashtable();
}
}
/**
* Create a standard attribute table from the passed in parameters - this will
* normally include contentType, signingTime, and messageDigest. If the constructor
* using an AttributeTable was used, entries in it for contentType, signingTime, and
* messageDigest will override the generated ones.
*
* @param parameters source parameters for table generation.
*
* @return a filled in Hashtable of attributes.
*/
protected virtual Hashtable createStandardAttributeTable(
IDictionary parameters)
{
Hashtable std = (Hashtable)table.Clone();
if (!std.ContainsKey(CmsAttributes.ContentType))
{
Asn1.Cms.Attribute attr = new Asn1.Cms.Attribute(CmsAttributes.ContentType,
new DerSet((DerObjectIdentifier)parameters[CmsAttributeTableParameter.ContentType]));
std[attr.AttrType] = attr;
}
if (!std.ContainsKey(CmsAttributes.SigningTime))
{
Asn1.Cms.Attribute attr = new Asn1.Cms.Attribute(
CmsAttributes.SigningTime, new DerSet(new Time(DateTime.UtcNow)));
std[attr.AttrType] = attr;
}
if (!std.ContainsKey(CmsAttributes.MessageDigest))
{
byte[] hash = (byte[])parameters[CmsAttributeTableParameter.Digest];
Asn1.Cms.Attribute attr;
if (hash != null)
{
attr = new Asn1.Cms.Attribute(
CmsAttributes.MessageDigest, new DerSet(new DerOctetString(hash)));
}
else
{
attr = new Asn1.Cms.Attribute(
CmsAttributes.MessageDigest, new DerSet(DerNull.Instance));
}
std[attr.AttrType] = attr;
}
return std;
}
/**
* @param parameters source parameters
* @return the populated attribute table
*/
public virtual AttributeTable GetAttributes(
IDictionary parameters)
{
return new AttributeTable(createStandardAttributeTable(parameters));
}
}
}