namespace System.Security.Cryptography.X509Certificates {
- public class X509Chain {
+ public class X509Chain : IDisposable {
- private StoreLocation location;
- private X509ChainElementCollection elements;
- private X509ChainPolicy policy;
- private X509ChainStatus[] status;
+ X509ChainImpl impl;
static X509ChainStatus[] Empty = new X509ChainStatus [0];
- // RFC3280 variables
- private int max_path_length;
- private X500DistinguishedName working_issuer_name;
-// private string working_public_key_algorithm;
- private AsymmetricAlgorithm working_public_key;
+ internal X509ChainImpl Impl {
+ get {
+ X509Helper2.ThrowIfContextInvalid (impl);
+ return impl;
+ }
+ }
- // other flags
- private X509ChainElement bce_restriction;
+ internal bool IsValid {
+ get { return X509Helper2.IsValid (impl); }
+ }
+
+ internal void ThrowIfContextInvalid ()
+ {
+ X509Helper2.ThrowIfContextInvalid (impl);
+ }
// constructors
public X509Chain (bool useMachineContext)
{
- location = useMachineContext ? StoreLocation.LocalMachine : StoreLocation.CurrentUser;
- elements = new X509ChainElementCollection ();
- policy = new X509ChainPolicy ();
+ impl = X509Helper2.CreateChainImpl (useMachineContext);
+ }
+
+ internal X509Chain (X509ChainImpl impl)
+ {
+ X509Helper2.ThrowIfContextInvalid (impl);
+ this.impl = impl;
}
[MonoTODO ("Mono's X509Chain is fully managed. All handles are invalid.")]
[MonoTODO ("Mono's X509Chain is fully managed. Always returns IntPtr.Zero.")]
public IntPtr ChainContext {
- get { return IntPtr.Zero; }
+ get {
+ if (impl != null && impl.IsValid)
+ return impl.Handle;
+ return IntPtr.Zero;
+ }
}
public X509ChainElementCollection ChainElements {
- get { return elements; }
+ get { return Impl.ChainElements; }
}
public X509ChainPolicy ChainPolicy {
- get { return policy; }
- set { policy = value; }
+ get { return Impl.ChainPolicy; }
+ set { Impl.ChainPolicy = value; }
}
public X509ChainStatus[] ChainStatus {
- get {
- if (status == null)
- return Empty;
- return status;
- }
- }
+ get { return Impl.ChainStatus; }
+ }
// methods
[MonoTODO ("Not totally RFC3280 compliant, but neither is MS implementation...")]
public bool Build (X509Certificate2 certificate)
{
- if (certificate == null)
- throw new ArgumentException ("certificate");
-
- Reset ();
- X509ChainStatusFlags flag;
- try {
- flag = BuildChainFrom (certificate);
- ValidateChain (flag);
- }
- catch (CryptographicException ce) {
- throw new ArgumentException ("certificate", ce);
- }
-
- X509ChainStatusFlags total = X509ChainStatusFlags.NoError;
- ArrayList list = new ArrayList ();
- // build "global" ChainStatus from the ChainStatus of every ChainElements
- foreach (X509ChainElement ce in elements) {
- foreach (X509ChainStatus cs in ce.ChainElementStatus) {
- // we MUST avoid duplicates in the "global" list
- if ((total & cs.Status) != cs.Status) {
- list.Add (cs);
- total |= cs.Status;
- }
- }
- }
- // and if required add some
- if (flag != X509ChainStatusFlags.NoError) {
- list.Insert (0, new X509ChainStatus (flag));
- }
- status = (X509ChainStatus[]) list.ToArray (typeof (X509ChainStatus));
-
- // (fast path) this ignore everything we have checked
- if ((status.Length == 0) || (ChainPolicy.VerificationFlags == X509VerificationFlags.AllFlags))
- return true;
-
- bool result = true;
- // now check if exclude some verification for the "end result" (boolean)
- foreach (X509ChainStatus cs in status) {
- switch (cs.Status) {
- case X509ChainStatusFlags.UntrustedRoot:
- case X509ChainStatusFlags.PartialChain:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.AllowUnknownCertificateAuthority) != 0);
- break;
- case X509ChainStatusFlags.NotTimeValid:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreNotTimeValid) != 0);
- break;
- // FIXME - from here we needs new test cases for all cases
- case X509ChainStatusFlags.NotTimeNested:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreNotTimeNested) != 0);
- break;
- case X509ChainStatusFlags.InvalidBasicConstraints:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreInvalidBasicConstraints) != 0);
- break;
- case X509ChainStatusFlags.InvalidPolicyConstraints:
- case X509ChainStatusFlags.NoIssuanceChainPolicy:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreInvalidPolicy) != 0);
- break;
- case X509ChainStatusFlags.InvalidNameConstraints:
- case X509ChainStatusFlags.HasNotSupportedNameConstraint:
- case X509ChainStatusFlags.HasNotPermittedNameConstraint:
- case X509ChainStatusFlags.HasExcludedNameConstraint:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreInvalidName) != 0);
- break;
- case X509ChainStatusFlags.InvalidExtension:
- // not sure ?!?
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreWrongUsage) != 0);
- break;
- //
- // ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreRootRevocationUnknown) != 0)
- // ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreEndRevocationUnknown) != 0)
- case X509ChainStatusFlags.CtlNotTimeValid:
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreCtlNotTimeValid) != 0);
- break;
- case X509ChainStatusFlags.CtlNotSignatureValid:
- // ?
- break;
- // ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreCtlSignerRevocationUnknown) != 0);
- case X509ChainStatusFlags.CtlNotValidForUsage:
- // FIXME - does IgnoreWrongUsage apply to CTL (it doesn't have Ctl in it's name like the others)
- result &= ((ChainPolicy.VerificationFlags & X509VerificationFlags.IgnoreWrongUsage) != 0);
- break;
- default:
- result = false;
- break;
- }
- // once we have one failure there's no need to check further
- if (!result)
- return false;
- }
-
- // every "problem" was excluded
- return true;
+ return Impl.Build (certificate);
}
public void Reset ()
{
- // note: this call doesn't Reset the X509ChainPolicy
- if ((status != null) && (status.Length != 0))
- status = null;
- if (elements.Count > 0)
- elements.Clear ();
- if (user_root_store != null) {
- user_root_store.Close ();
- user_root_store = null;
- }
- if (root_store != null) {
- root_store.Close ();
- root_store = null;
- }
- if (user_ca_store != null) {
- user_ca_store.Close ();
- user_ca_store = null;
- }
- if (ca_store != null) {
- ca_store.Close ();
- ca_store = null;
- }
- roots = null;
- cas = null;
- collection = null;
- bce_restriction = null;
- working_public_key = null;
+ Impl.Reset ();
}
// static methods
#endif
}
- // private stuff
-
- private X509Certificate2Collection roots;
- private X509Certificate2Collection cas;
- private X509Store root_store;
- private X509Store ca_store;
- private X509Store user_root_store;
- private X509Store user_ca_store;
-
- private X509Certificate2Collection Roots {
- get {
- if (roots == null) {
- X509Certificate2Collection c = new X509Certificate2Collection ();
- X509Store store = LMRootStore;
- if (location == StoreLocation.CurrentUser)
- c.AddRange (UserRootStore.Certificates);
- c.AddRange (store.Certificates);
- roots = c;
- }
- return roots;
- }
- }
-
- private X509Certificate2Collection CertificateAuthorities {
- get {
- if (cas == null) {
- X509Certificate2Collection c = new X509Certificate2Collection ();
- X509Store store = LMCAStore;
- if (location == StoreLocation.CurrentUser)
- c.AddRange (UserCAStore.Certificates);
- c.AddRange (store.Certificates);
- cas = c;
- }
- return cas;
- }
- }
-
- private X509Store LMRootStore {
- get {
- if (root_store == null) {
- root_store = new X509Store (StoreName.Root, StoreLocation.LocalMachine);
- try {
- root_store.Open (OpenFlags.OpenExistingOnly | OpenFlags.ReadOnly);
- } catch {
- }
- }
- return root_store;
- }
- }
-
- private X509Store UserRootStore {
- get {
- if (user_root_store == null) {
- user_root_store = new X509Store (StoreName.Root, StoreLocation.CurrentUser);
- try {
- user_root_store.Open (OpenFlags.OpenExistingOnly | OpenFlags.ReadOnly);
- } catch {
- }
- }
- return user_root_store;
- }
- }
-
- private X509Store LMCAStore {
- get {
- if (ca_store == null) {
- ca_store = new X509Store (StoreName.CertificateAuthority, StoreLocation.LocalMachine);
- try {
- ca_store.Open (OpenFlags.OpenExistingOnly | OpenFlags.ReadOnly);
- } catch {
- }
- }
- return ca_store;
- }
- }
-
- private X509Store UserCAStore {
- get {
- if (user_ca_store == null) {
- user_ca_store = new X509Store (StoreName.CertificateAuthority, StoreLocation.CurrentUser);
- try {
- user_ca_store.Open (OpenFlags.OpenExistingOnly | OpenFlags.ReadOnly);
- } catch {
- }
- }
- return user_ca_store;
- }
- }
- // *** certificate chain/path building stuff ***
-
- private X509Certificate2Collection collection;
-
- // we search local user (default) or machine certificate store
- // and in the extra certificate supplied in ChainPolicy.ExtraStore
- private X509Certificate2Collection CertificateCollection {
- get {
- if (collection == null) {
- collection = new X509Certificate2Collection (ChainPolicy.ExtraStore);
- collection.AddRange (Roots);
- collection.AddRange (CertificateAuthorities);
- }
- return collection;
- }
- }
-
- // This is a non-recursive chain/path building algorithm.
- //
- // At this stage we only checks for PartialChain, Cyclic and UntrustedRoot errors are they
- // affect the path building (other errors are verification errors).
- //
- // Note that the order match the one we need to match MS and not the one defined in RFC3280,
- // we also include the trusted root certificate (trust anchor in RFC3280) in the list.
- // (this isn't an issue, just keep that in mind if you look at the source and the RFC)
- private X509ChainStatusFlags BuildChainFrom (X509Certificate2 certificate)
- {
- elements.Add (certificate);
-
- while (!IsChainComplete (certificate)) {
- certificate = FindParent (certificate);
-
- if (certificate == null)
- return X509ChainStatusFlags.PartialChain;
-
- if (elements.Contains (certificate))
- return X509ChainStatusFlags.Cyclic;
-
- elements.Add (certificate);
- }
-
- // roots may be supplied (e.g. in the ExtraStore) so we need to confirm their
- // trustiness (what a cute word) in the trusted root collection
- if (!Roots.Contains (certificate))
- elements [elements.Count - 1].StatusFlags |= X509ChainStatusFlags.UntrustedRoot;
-
- return X509ChainStatusFlags.NoError;
- }
-
-
- private X509Certificate2 SelectBestFromCollection (X509Certificate2 child, X509Certificate2Collection c)
- {
- switch (c.Count) {
- case 0:
- return null;
- case 1:
- return c [0];
- default:
- // multiple candidate, keep only the ones that are still valid
- X509Certificate2Collection time_valid = c.Find (X509FindType.FindByTimeValid, ChainPolicy.VerificationTime, false);
- switch (time_valid.Count) {
- case 0:
- // that's too restrictive, let's revert and try another thing...
- time_valid = c;
- break;
- case 1:
- return time_valid [0];
- default:
- break;
- }
-
- // again multiple candidates, let's find the AKI that match the SKI (if we have one)
- string aki = GetAuthorityKeyIdentifier (child);
- if (String.IsNullOrEmpty (aki)) {
- return time_valid [0]; // FIXME: out of luck, you get the first one
- }
- foreach (X509Certificate2 parent in time_valid) {
- string ski = GetSubjectKeyIdentifier (parent);
- // if both id are available then they must match
- if (aki == ski)
- return parent;
- }
- return time_valid [0]; // FIXME: out of luck, you get the first one
- }
- }
-
- private X509Certificate2 FindParent (X509Certificate2 certificate)
- {
- X509Certificate2Collection subset = CertificateCollection.Find (X509FindType.FindBySubjectDistinguishedName, certificate.Issuer, false);
- string aki = GetAuthorityKeyIdentifier (certificate);
- if ((aki != null) && (aki.Length > 0)) {
- subset.AddRange (CertificateCollection.Find (X509FindType.FindBySubjectKeyIdentifier, aki, false));
- }
- X509Certificate2 parent = SelectBestFromCollection (certificate, subset);
- // if parent==certificate we're looping but it's not (probably) a bug and not a true cyclic (over n certs)
- return certificate.Equals (parent) ? null : parent;
- }
-
- private bool IsChainComplete (X509Certificate2 certificate)
+ public void Dispose ()
{
- // the chain is complete if we have a self-signed certificate
- if (!IsSelfIssued (certificate))
- return false;
-
- // we're very limited to what we can do without certificate extensions
- if (certificate.Version < 3)
- return true;
-
- // check that Authority Key Identifier == Subject Key Identifier
- // e.g. it will be different if a self-signed certificate is part (not the end) of the chain
- string ski = GetSubjectKeyIdentifier (certificate);
- if (String.IsNullOrEmpty (ski))
- return true;
- string aki = GetAuthorityKeyIdentifier (certificate);
- if (String.IsNullOrEmpty (aki))
- return true;
- // if both id are available then they must match
- return (aki == ski);
+ Dispose (true);
+ GC.SuppressFinalize (this);
}
- // check for "self-issued" certificate - without verifying the signature
- // note that self-issued doesn't always mean it's a root certificate!
- private bool IsSelfIssued (X509Certificate2 certificate)
+ protected virtual void Dispose (bool disposing)
{
- return (certificate.Issuer == certificate.Subject);
- }
-
-
- // *** certificate chain/path validation stuff ***
-
- // Currently a subset of RFC3280 (hopefully a full implementation someday)
- private void ValidateChain (X509ChainStatusFlags flag)
- {
- // 'n' should be the root certificate...
- int n = elements.Count - 1;
- X509Certificate2 certificate = elements [n].Certificate;
-
- // ... and, if so, must be treated outside the chain...
- if (((flag & X509ChainStatusFlags.PartialChain) == 0)) {
- Process (n);
- // deal with the case where the chain == the root certificate
- // (which isn't for RFC3280) part of the chain
- if (n == 0) {
- elements [0].UncompressFlags ();
- return;
- }
- // skip the root certificate when processing the chain (in 6.1.3)
- n--;
- }
- // ... unless the chain is a partial one (then we start with that one)
-
- // 6.1.1 - Inputs
- // 6.1.1.a - a prospective certificate path of length n (i.e. elements)
- // 6.1.1.b - the current date/time (i.e. ChainPolicy.VerificationTime)
- // 6.1.1.c - user-initial-policy-set (i.e. ChainPolicy.CertificatePolicy)
- // 6.1.1.d - the trust anchor information (i.e. certificate, unless it's a partial chain)
- // 6.1.1.e - initial-policy-mapping-inhibit (NOT SUPPORTED BY THE API)
- // 6.1.1.f - initial-explicit-policy (NOT SUPPORTED BY THE API)
- // 6.1.1.g - initial-any-policy-inhibit (NOT SUPPORTED BY THE API)
-
- // 6.1.2 - Initialization (incomplete)
- // 6.1.2.a-f - policy stuff, some TODO, some not supported
- // 6.1.2.g - working public key algorithm
-// working_public_key_algorithm = certificate.PublicKey.Oid.Value;
- // 6.1.2.h-i - our key contains both the "working public key" and "working public key parameters" data
- working_public_key = certificate.PublicKey.Key;
- // 6.1.2.j - working issuer name
- working_issuer_name = certificate.IssuerName;
- // 6.1.2.k - this integer is initialized to n, is decremented for each non-self-issued, certificate and
- // may be reduced to the value in the path length constraint field
- max_path_length = n;
-
- // 6.1.3 - Basic Certificate Processing
- // note: loop looks reversed (the list is) but we process this part just like RFC3280 does
- for (int i = n; i > 0; i--) {
- Process (i);
- // 6.1.4 - preparation for certificate i+1 (for not with i+1, or i-1 in our loop)
- PrepareForNextCertificate (i);
+ if (impl != null) {
+ impl.Dispose ();
+ impl = null;
}
- Process (0);
-
- // 6.1.3.a.3 - revocation checks
- CheckRevocationOnChain (flag);
-
- // 6.1.5 - Wrap-up procedure
- WrapUp ();
}
- private void Process (int n)
+ ~X509Chain ()
{
- X509ChainElement element = elements [n];
- X509Certificate2 certificate = element.Certificate;
-
- // pre-step: DSA certificates may inherit the parameters of their CA
- if ((n != elements.Count - 1) && (certificate.MonoCertificate.KeyAlgorithm == "1.2.840.10040.4.1")) {
- if (certificate.MonoCertificate.KeyAlgorithmParameters == null) {
- X509Certificate2 parent = elements [n+1].Certificate;
- certificate.MonoCertificate.KeyAlgorithmParameters = parent.MonoCertificate.KeyAlgorithmParameters;
- }
- }
-
- bool root = (working_public_key == null);
- // 6.1.3.a.1 - check signature (with special case to deal with root certificates)
- if (!IsSignedWith (certificate, root ? certificate.PublicKey.Key : working_public_key)) {
- // another special case where only an end-entity is available and can't be verified.
- // In this case we do not report an invalid signature (since this is unknown)
- if (root || (n != elements.Count - 1) || IsSelfIssued (certificate)) {
- element.StatusFlags |= X509ChainStatusFlags.NotSignatureValid;
- }
- }
-
- // 6.1.3.a.2 - check validity period
- if ((ChainPolicy.VerificationTime < certificate.NotBefore) ||
- (ChainPolicy.VerificationTime > certificate.NotAfter)) {
- element.StatusFlags |= X509ChainStatusFlags.NotTimeValid;
- }
- // TODO - for X509ChainStatusFlags.NotTimeNested (needs global structure)
-
- // note: most of them don't apply to the root certificate
- if (root) {
- return;
- }
-
- // 6.1.3.a.3 - revocation check (we're doing at the last stage)
- // note: you revoke a trusted root by removing it from your trusted store (i.e. no CRL can do this job)
-
- // 6.1.3.a.4 - check certificate issuer name
- if (!X500DistinguishedName.AreEqual (certificate.IssuerName, working_issuer_name)) {
- // NOTE: this is not the "right" error flag, but it's the closest one defined
- element.StatusFlags |= X509ChainStatusFlags.InvalidNameConstraints;
- }
-
- if (!IsSelfIssued (certificate) && (n != 0)) {
- // TODO 6.1.3.b - subject name in the permitted_subtrees ...
- // TODO 6.1.3.c - subject name not within excluded_subtrees...
-
- // TODO - check for X509ChainStatusFlags.InvalidNameConstraint
- // TODO - check for X509ChainStatusFlags.HasNotSupportedNameConstraint
- // TODO - check for X509ChainStatusFlags.HasNotPermittedNameConstraint
- // TODO - check for X509ChainStatusFlags.HasExcludedNameConstraint
- }
-
- // TODO 6.1.3.d - check if certificate policies extension is present
- //if (false) {
- // TODO - for X509ChainStatusFlags.InvalidPolicyConstraints
- // using X509ChainPolicy.ApplicationPolicy and X509ChainPolicy.CertificatePolicy
-
- // TODO - check for X509ChainStatusFlags.NoIssuanceChainPolicy
-
- //} else {
- // TODO 6.1.3.e - set valid_policy_tree to NULL
- //}
-
- // TODO 6.1.3.f - verify explict_policy > 0 if valid_policy_tree != NULL
- }
-
- // CTL == Certificate Trust List / NOT SUPPORTED
- // TODO - check for X509ChainStatusFlags.CtlNotTimeValid
- // TODO - check for X509ChainStatusFlags.CtlNotSignatureValid
- // TODO - check for X509ChainStatusFlags.CtlNotValidForUsage
-
- private void PrepareForNextCertificate (int n)
- {
- X509ChainElement element = elements [n];
- X509Certificate2 certificate = element.Certificate;
-
- // TODO 6.1.4.a-b
-
- // 6.1.4.c
- working_issuer_name = certificate.SubjectName;
- // 6.1.4.d-e - our key includes both the public key and it's parameters
- working_public_key = certificate.PublicKey.Key;
- // 6.1.4.f
-// working_public_key_algorithm = certificate.PublicKey.Oid.Value;
-
- // TODO 6.1.4.g-j
-
- // 6.1.4.k - Verify that the certificate is a CA certificate
- X509BasicConstraintsExtension bce = (certificate.Extensions["2.5.29.19"] as X509BasicConstraintsExtension);
- if (bce != null) {
- if (!bce.CertificateAuthority) {
- element.StatusFlags |= X509ChainStatusFlags.InvalidBasicConstraints;
- }
- } else if (certificate.Version >= 3) {
- // recent (v3+) CA certificates must include BCE
- element.StatusFlags |= X509ChainStatusFlags.InvalidBasicConstraints;
- }
-
- // 6.1.4.l - if the certificate isn't self-issued...
- if (!IsSelfIssued (certificate)) {
- // ... verify that max_path_length > 0
- if (max_path_length > 0) {
- max_path_length--;
- } else {
- // to match MS the reported status must be against the certificate
- // with the BCE and not where the path is too long. It also means
- // that this condition has to be reported only once
- if (bce_restriction != null) {
- bce_restriction.StatusFlags |= X509ChainStatusFlags.InvalidBasicConstraints;
- }
- }
- }
-
- // 6.1.4.m - if pathLengthConstraint is present...
- if ((bce != null) && (bce.HasPathLengthConstraint)) {
- // ... and is less that max_path_length, set max_path_length to it's value
- if (bce.PathLengthConstraint < max_path_length) {
- max_path_length = bce.PathLengthConstraint;
- bce_restriction = element;
- }
- }
-
- // 6.1.4.n - if key usage extension is present...
- X509KeyUsageExtension kue = (certificate.Extensions["2.5.29.15"] as X509KeyUsageExtension);
- if (kue != null) {
- // ... verify keyCertSign is set
- X509KeyUsageFlags success = X509KeyUsageFlags.KeyCertSign;
- if ((kue.KeyUsages & success) != success)
- element.StatusFlags |= X509ChainStatusFlags.NotValidForUsage;
- }
-
- // 6.1.4.o - recognize and process other critical extension present in the certificate
- ProcessCertificateExtensions (element);
- }
-
- private void WrapUp ()
- {
- X509ChainElement element = elements [0];
- X509Certificate2 certificate = element.Certificate;
-
- // 6.1.5.a - TODO if certificate n (our 0) wasn't self issued and explicit_policy != 0
- if (IsSelfIssued (certificate)) {
- // TODO... decrement explicit_policy by 1
- }
-
- // 6.1.5.b - TODO
-
- // 6.1.5.c,d,e - not required by the X509Chain implementation
-
- // 6.1.5.f - recognize and process other critical extension present in the certificate
- ProcessCertificateExtensions (element);
-
- // 6.1.5.g - TODO
-
- // uncompressed the flags into several elements
- for (int i = elements.Count - 1; i >= 0; i--) {
- elements [i].UncompressFlags ();
- }
- }
-
- private void ProcessCertificateExtensions (X509ChainElement element)
- {
- foreach (X509Extension ext in element.Certificate.Extensions) {
- if (ext.Critical) {
- switch (ext.Oid.Value) {
- case "2.5.29.15": // X509KeyUsageExtension
- case "2.5.29.19": // X509BasicConstraintsExtension
- // we processed this extension
- break;
- default:
- // note: Under Windows XP MS implementation seems to ignore
- // certificate with unknown critical extensions.
- element.StatusFlags |= X509ChainStatusFlags.InvalidExtension;
- break;
- }
- }
- }
- }
-
- private bool IsSignedWith (X509Certificate2 signed, AsymmetricAlgorithm pubkey)
- {
- if (pubkey == null)
- return false;
- // Sadly X509Certificate2 doesn't expose the signature nor the tbs (to be signed) structure
- MX.X509Certificate mx = signed.MonoCertificate;
- return (mx.VerifySignature (pubkey));
- }
-
- private string GetSubjectKeyIdentifier (X509Certificate2 certificate)
- {
- X509SubjectKeyIdentifierExtension ski = (certificate.Extensions["2.5.29.14"] as X509SubjectKeyIdentifierExtension);
- return (ski == null) ? String.Empty : ski.SubjectKeyIdentifier;
- }
-
- // System.dll v2 doesn't have a class to deal with the AuthorityKeyIdentifier extension
- static string GetAuthorityKeyIdentifier (X509Certificate2 certificate)
- {
- return GetAuthorityKeyIdentifier (certificate.MonoCertificate.Extensions ["2.5.29.35"]);
- }
-
- // but anyway System.dll v2 doesn't expose CRL in any way so...
- static string GetAuthorityKeyIdentifier (MX.X509Crl crl)
- {
- return GetAuthorityKeyIdentifier (crl.Extensions ["2.5.29.35"]);
- }
-
- static string GetAuthorityKeyIdentifier (MX.X509Extension ext)
- {
- if (ext == null)
- return String.Empty;
- MX.Extensions.AuthorityKeyIdentifierExtension aki = new MX.Extensions.AuthorityKeyIdentifierExtension (ext);
- byte[] id = aki.Identifier;
- if (id == null)
- return String.Empty;
- StringBuilder sb = new StringBuilder ();
- foreach (byte b in id)
- sb.Append (b.ToString ("X02"));
- return sb.ToString ();
- }
-
- // we check the revocation only once we have built the complete chain
- private void CheckRevocationOnChain (X509ChainStatusFlags flag)
- {
- bool partial = ((flag & X509ChainStatusFlags.PartialChain) != 0);
- bool online;
-
- switch (ChainPolicy.RevocationMode) {
- case X509RevocationMode.Online:
- // default
- online = true;
- break;
- case X509RevocationMode.Offline:
- online = false;
- break;
- case X509RevocationMode.NoCheck:
- return;
- default:
- throw new InvalidOperationException (Locale.GetText ("Invalid revocation mode."));
- }
-
- bool unknown = partial;
- // from the root down to the end-entity
- for (int i = elements.Count - 1; i >= 0; i--) {
- bool check = true;
-
- switch (ChainPolicy.RevocationFlag) {
- case X509RevocationFlag.EndCertificateOnly:
- check = (i == 0);
- break;
- case X509RevocationFlag.EntireChain:
- check = true;
- break;
- case X509RevocationFlag.ExcludeRoot:
- // default
- check = (i != (elements.Count - 1));
- // anyway, who's gonna sign that the root is invalid ?
- break;
- }
-
- X509ChainElement element = elements [i];
-
- // we can't assume the revocation status if the certificate is bad (e.g. invalid signature)
- if (!unknown)
- unknown |= ((element.StatusFlags & X509ChainStatusFlags.NotSignatureValid) != 0);
-
- if (unknown) {
- // we can skip the revocation checks as we can't be sure of them anyway
- element.StatusFlags |= X509ChainStatusFlags.RevocationStatusUnknown;
- element.StatusFlags |= X509ChainStatusFlags.OfflineRevocation;
- } else if (check && !partial && !IsSelfIssued (element.Certificate)) {
- // check for revocation (except for the trusted root and self-issued certs)
- element.StatusFlags |= CheckRevocation (element.Certificate, i+1, online);
- // if revoked, then all others following in the chain are unknown...
- unknown |= ((element.StatusFlags & X509ChainStatusFlags.Revoked) != 0);
- }
- }
- }
-
- // This isn't how RFC3280 (section 6.3) deals with CRL, but then we don't (yet) support DP, deltas...
- private X509ChainStatusFlags CheckRevocation (X509Certificate2 certificate, int ca, bool online)
- {
- X509ChainStatusFlags result = X509ChainStatusFlags.RevocationStatusUnknown;
- X509ChainElement element = elements [ca];
- X509Certificate2 ca_cert = element.Certificate;
-
- // find the CRL from the "right" CA
- while (IsSelfIssued (ca_cert) && (ca < elements.Count - 1)) {
- // try with this self-issued
- result = CheckRevocation (certificate, ca_cert, online);
- if (result != X509ChainStatusFlags.RevocationStatusUnknown)
- break;
- ca++;
- element = elements [ca];
- ca_cert = element.Certificate;
- }
- if (result == X509ChainStatusFlags.RevocationStatusUnknown)
- result = CheckRevocation (certificate, ca_cert, online);
- return result;
- }
-
- private X509ChainStatusFlags CheckRevocation (X509Certificate2 certificate, X509Certificate2 ca_cert, bool online)
- {
- // change this if/when we support OCSP
- X509KeyUsageExtension kue = (ca_cert.Extensions["2.5.29.15"] as X509KeyUsageExtension);
- if (kue != null) {
- // ... verify CrlSign is set
- X509KeyUsageFlags success = X509KeyUsageFlags.CrlSign;
- if ((kue.KeyUsages & success) != success) {
- // FIXME - we should try to find an alternative CA that has the CrlSign bit
- return X509ChainStatusFlags.RevocationStatusUnknown;
- }
- }
-
- MX.X509Crl crl = FindCrl (ca_cert);
-
- if ((crl == null) && online) {
- // FIXME - download and install new CRL
- // then you get a second chance
- // crl = FindCrl (ca_cert, ref valid, ref out_of_date);
-
- // We need to get the subjectAltName and an URI from there (or use OCSP)
- // X509KeyUsageExtension subjectAltName = (ca_cert.Extensions["2.5.29.17"] as X509KeyUsageExtension);
- }
-
- if (crl != null) {
- // validate the digital signature on the CRL using the CA public key
- // note #1: we can't use X509Crl.VerifySignature(X509Certificate) because it duplicates
- // checks and we loose the "why" of the failure
- // note #2: we do this before other tests as an invalid signature could be a hacked CRL
- // (so anything within can't be trusted)
- if (!crl.VerifySignature (ca_cert.PublicKey.Key)) {
- return X509ChainStatusFlags.RevocationStatusUnknown;
- }
-
- MX.X509Crl.X509CrlEntry entry = crl.GetCrlEntry (certificate.MonoCertificate);
- if (entry != null) {
- // We have an entry for this CRL that includes an unknown CRITICAL extension
- // See [X.509 7.3] NOTE 4
- if (!ProcessCrlEntryExtensions (entry))
- return X509ChainStatusFlags.Revoked;
-
- // FIXME - a little more is involved
- if (entry.RevocationDate <= ChainPolicy.VerificationTime)
- return X509ChainStatusFlags.Revoked;
- }
-
- // are we overdue for a CRL update ? if so we can't be sure of any certificate status
- if (crl.NextUpdate < ChainPolicy.VerificationTime)
- return X509ChainStatusFlags.RevocationStatusUnknown | X509ChainStatusFlags.OfflineRevocation;
-
- // we have a CRL that includes an unknown CRITICAL extension
- // we put this check at the end so we do not "hide" any Revoked flags
- if (!ProcessCrlExtensions (crl)) {
- return X509ChainStatusFlags.RevocationStatusUnknown;
- }
- } else {
- return X509ChainStatusFlags.RevocationStatusUnknown;
- }
-
- return X509ChainStatusFlags.NoError;
- }
-
- static MX.X509Crl CheckCrls (string subject, string ski, MX.X509Store store)
- {
- if (store == null)
- return null;
-
- var crls = store.Crls;
- foreach (MX.X509Crl crl in crls) {
- if (crl.IssuerName == subject && (ski.Length == 0 || ski == GetAuthorityKeyIdentifier (crl)))
- return crl;
- }
- return null; // No CRL found
- }
-
- private MX.X509Crl FindCrl (X509Certificate2 caCertificate)
- {
- string subject = caCertificate.SubjectName.Decode (X500DistinguishedNameFlags.None);
- string ski = GetSubjectKeyIdentifier (caCertificate);
-
- // consider that the LocalMachine directories could not exists... and cannot be created by the user
- MX.X509Crl result = CheckCrls (subject, ski, LMCAStore.Store);
- if (result != null)
- return result;
- if (location == StoreLocation.CurrentUser) {
- result = CheckCrls (subject, ski, UserCAStore.Store);
- if (result != null)
- return result;
- }
-
- // consider that the LocalMachine directories could not exists... and cannot be created by the user
- result = CheckCrls (subject, ski, LMRootStore.Store);
- if (result != null)
- return result;
- if (location == StoreLocation.CurrentUser) {
- result = CheckCrls (subject, ski, UserRootStore.Store);
- if (result != null)
- return result;
- }
- return null;
- }
-
- private bool ProcessCrlExtensions (MX.X509Crl crl)
- {
- foreach (MX.X509Extension ext in crl.Extensions) {
- if (ext.Critical) {
- switch (ext.Oid) {
- case "2.5.29.20": // cRLNumber
- case "2.5.29.35": // authorityKeyIdentifier
- // we processed/know about this extension
- break;
- default:
- return false;
- }
- }
- }
- return true;
- }
-
- private bool ProcessCrlEntryExtensions (MX.X509Crl.X509CrlEntry entry)
- {
- foreach (MX.X509Extension ext in entry.Extensions) {
- if (ext.Critical) {
- switch (ext.Oid) {
- case "2.5.29.21": // cRLReason
- // we processed/know about this extension
- break;
- default:
- return false;
- }
- }
- }
- return true;
+ Dispose (false);
}
}
}
projects / mono.git / blobdiff