// get a pre-builded chain
public X509Chain(X509CertificateCollection chain) : this()
{
_chain = new X509CertificateCollection();
_chain.AddRange(chain);
}
public bool Build(X509Certificate leaf)
{
_status = X509ChainStatusFlags.NoError;
if (_chain == null)
{
// chain not supplied - we must build it ourselve
_chain = new X509CertificateCollection();
X509Certificate x = leaf;
X509Certificate tmp = x;
while ((x != null) && (!x.IsSelfSigned))
{
tmp = x; // last valid
_chain.Add(x);
x = FindCertificateParent(x);
}
// find a trusted root
_root = FindCertificateRoot(tmp);
}
else
{
// chain supplied - still have to check signatures!
int last = _chain.Count;
if (last > 0)
{
if (IsParent(leaf, _chain [0]))
{
int i = 1;
for (; i < last; i++)
{
if (!IsParent(_chain [i - 1], _chain [i]))
{
break;
}
}
if (i == last)
{
_root = FindCertificateRoot(_chain [last - 1]);
}
}
}
else
{
// is the leaf a root ? (trusted or untrusted)
_root = FindCertificateRoot(leaf);
}
}
// validate the chain
if ((_chain != null) && (_status == X509ChainStatusFlags.NoError))
{
foreach (X509Certificate x in _chain)
{
// validate dates for each certificate in the chain
// note: we DO NOT check for nested date/time
if (!IsValid(x))
{
return(false);
}
}
// check leaf
if (!IsValid(leaf))
{
// switch status code if the failure is expiration
if (_status == X509ChainStatusFlags.NotTimeNested)
{
_status = X509ChainStatusFlags.NotTimeValid;
}
return(false);
}
// check root
if ((_root != null) && !IsValid(_root))
{
return(false);
}
}
return(_status == X509ChainStatusFlags.NoError);
}
// constructors
public X509Chain()
{
certs = new X509CertificateCollection();
}
public void LoadCertificates(X509CertificateCollection collection)
{
certs.AddRange(collection);
}