3 #if MONO_SECURITY_ALIAS
4 extern alias MonoSecurity;
7 extern alias PrebuiltSystem;
10 #if MONO_SECURITY_ALIAS
11 using MonoSecurity::Mono.Security.Interface;
12 using MSX = MonoSecurity::Mono.Security.X509;
13 using MonoSecurity::Mono.Security.X509.Extensions;
15 using Mono.Security.Interface;
16 using MSX = Mono.Security.X509;
17 using Mono.Security.X509.Extensions;
20 using XX509CertificateCollection = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509CertificateCollection;
21 using XX509Chain = PrebuiltSystem::System.Security.Cryptography.X509Certificates.X509Chain;
23 using XX509CertificateCollection = System.Security.Cryptography.X509Certificates.X509CertificateCollection;
24 using XX509Chain = System.Security.Cryptography.X509Certificates.X509Chain;
29 using System.Threading;
30 using System.Collections;
31 using System.Collections.Generic;
32 using System.Collections.Specialized;
33 using System.Configuration;
34 using System.Net.Configuration;
35 using System.Text.RegularExpressions;
36 using System.Security.Cryptography.X509Certificates;
38 using System.Globalization;
39 using System.Net.Security;
40 using System.Diagnostics;
42 namespace Mono.Net.Security
44 internal static class SystemCertificateValidator
46 static bool is_macosx;
48 static X509RevocationMode revocation_mode;
51 static SystemCertificateValidator ()
58 is_macosx = System.IO.File.Exists (OSX509Certificates.SecurityLibrary);
62 revocation_mode = X509RevocationMode.NoCheck;
64 string str = Environment.GetEnvironmentVariable ("MONO_X509_REVOCATION_MODE");
65 if (String.IsNullOrEmpty (str))
67 revocation_mode = (X509RevocationMode)Enum.Parse (typeof(X509RevocationMode), str, true);
73 public static X509Chain CreateX509Chain (XX509CertificateCollection certs)
75 var chain = new X509Chain ();
76 chain.ChainPolicy = new X509ChainPolicy ();
79 chain.ChainPolicy.RevocationMode = revocation_mode;
82 for (int i = 1; i < certs.Count; i++) {
83 chain.ChainPolicy.ExtraStore.Add (certs [i]);
89 static bool BuildX509Chain (XX509CertificateCollection certs, X509Chain chain, ref SslPolicyErrors errors, ref int status11)
97 var leaf = (X509Certificate2)certs [0];
101 ok = chain.Build (leaf);
103 errors |= GetErrorsFromChain (chain);
104 } catch (Exception e) {
105 Console.Error.WriteLine ("ERROR building certificate chain: {0}", e);
106 Console.Error.WriteLine ("Please, report this problem to the Mono team");
107 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
112 status11 = GetStatusFromChain (chain);
114 status11 = -2146762485; // TRUST_E_FAIL - generic
121 static bool CheckUsage (XX509CertificateCollection certs, string host, ref SslPolicyErrors errors, ref int status11)
124 var leaf = certs[0] as X509Certificate2;
126 leaf = new X509Certificate2 (certs[0]);
127 // for OSX and iOS we're using the native API to check for the SSL server policy and host names
129 if (!CheckCertificateUsage (leaf)) {
130 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
131 status11 = -2146762490; //CERT_E_PURPOSE 0x800B0106
135 if (!string.IsNullOrEmpty (host) && !CheckServerIdentity (leaf, host)) {
136 errors |= SslPolicyErrors.RemoteCertificateNameMismatch;
137 status11 = -2146762481; // CERT_E_CN_NO_MATCH 0x800B010F
145 static bool EvaluateSystem (XX509CertificateCollection certs, XX509CertificateCollection anchors, string host, X509Chain chain, ref SslPolicyErrors errors, ref int status11)
147 var leaf = certs [0];
151 result = AndroidPlatform.TrustEvaluateSsl (certs);
153 // chain.Build() + GetErrorsFromChain() (above) will ALWAYS fail on
154 // Android (there are no mozroots or preinstalled root certificates),
155 // thus `errors` will ALWAYS have RemoteCertificateChainErrors.
156 // Android just verified the chain; clear RemoteCertificateChainErrors.
157 errors &= ~SslPolicyErrors.RemoteCertificateChainErrors;
161 // Attempt to use OSX certificates
162 // Ideally we should return the SecTrustResult
163 OSX509Certificates.SecTrustResult trustResult = OSX509Certificates.SecTrustResult.Deny;
165 trustResult = OSX509Certificates.TrustEvaluateSsl (certs, anchors, host);
166 // We could use the other values of trustResult to pass this extra information
167 // to the .NET 2 callback for values like SecTrustResult.Confirm
168 result = (trustResult == OSX509Certificates.SecTrustResult.Proceed ||
169 trustResult == OSX509Certificates.SecTrustResult.Unspecified);
172 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
177 // TrustEvaluateSsl was successful so there's no trust error
178 // IOW we discard our own chain (since we trust OSX one instead)
181 // callback and DefaultCertificatePolicy needs this since 'result' is not specified
182 status11 = (int)trustResult;
183 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
186 result = BuildX509Chain (certs, chain, ref errors, ref status11);
193 public static bool Evaluate (
194 MonoTlsSettings settings, string host, XX509CertificateCollection certs,
195 X509Chain chain, ref SslPolicyErrors errors, ref int status11)
197 if (!CheckUsage (certs, host, ref errors, ref status11))
200 if (settings != null && settings.SkipSystemValidators)
203 var anchors = settings != null ? settings.TrustAnchors : null;
204 return EvaluateSystem (certs, anchors, host, chain, ref errors, ref status11);
207 internal static bool NeedsChain (MonoTlsSettings settings)
214 if (!CertificateValidationHelper.SupportsX509Chain)
216 if (settings != null)
217 return !settings.SkipSystemValidators || settings.CallbackNeedsCertificateChain;
224 static int GetStatusFromChain (X509Chain chain)
227 foreach (var status in chain.ChainStatus) {
228 X509ChainStatusFlags flags = status.Status;
229 if (flags == X509ChainStatusFlags.NoError)
233 if ((flags & X509ChainStatusFlags.NotTimeValid) != 0)
235 // CERT_E_VALIDITYPERIODNESTING
236 else if ((flags & X509ChainStatusFlags.NotTimeNested) != 0)
239 else if ((flags & X509ChainStatusFlags.Revoked) != 0)
241 // TRUST_E_CERT_SIGNATURE
242 else if ((flags & X509ChainStatusFlags.NotSignatureValid) != 0)
244 // CERT_E_WRONG_USAGE
245 else if ((flags & X509ChainStatusFlags.NotValidForUsage) != 0)
247 // CERT_E_UNTRUSTEDROOT
248 else if ((flags & X509ChainStatusFlags.UntrustedRoot) != 0)
250 // CRYPT_E_NO_REVOCATION_CHECK
251 else if ((flags & X509ChainStatusFlags.RevocationStatusUnknown) != 0)
254 else if ((flags & X509ChainStatusFlags.Cyclic) != 0)
256 // TRUST_E_FAIL - generic
257 else if ((flags & X509ChainStatusFlags.InvalidExtension) != 0)
259 // CERT_E_UNTRUSTEDROOT
260 else if ((flags & X509ChainStatusFlags.InvalidPolicyConstraints) != 0)
262 // TRUST_E_BASIC_CONSTRAINTS
263 else if ((flags & X509ChainStatusFlags.InvalidBasicConstraints) != 0)
265 // CERT_E_INVALID_NAME
266 else if ((flags & X509ChainStatusFlags.InvalidNameConstraints) != 0)
268 // CERT_E_INVALID_NAME
269 else if ((flags & X509ChainStatusFlags.HasNotSupportedNameConstraint) != 0)
271 // CERT_E_INVALID_NAME
272 else if ((flags & X509ChainStatusFlags.HasNotDefinedNameConstraint) != 0)
274 // CERT_E_INVALID_NAME
275 else if ((flags & X509ChainStatusFlags.HasNotPermittedNameConstraint) != 0)
277 // CERT_E_INVALID_NAME
278 else if ((flags & X509ChainStatusFlags.HasExcludedNameConstraint) != 0)
281 else if ((flags & X509ChainStatusFlags.PartialChain) != 0)
284 else if ((flags & X509ChainStatusFlags.CtlNotTimeValid) != 0)
286 // TRUST_E_CERT_SIGNATURE
287 else if ((flags & X509ChainStatusFlags.CtlNotSignatureValid) != 0)
289 // CERT_E_WRONG_USAGE
290 else if ((flags & X509ChainStatusFlags.CtlNotValidForUsage) != 0)
292 // CRYPT_E_NO_REVOCATION_CHECK
293 else if ((flags & X509ChainStatusFlags.OfflineRevocation) != 0)
295 // CERT_E_ISSUERCHAINING
296 else if ((flags & X509ChainStatusFlags.NoIssuanceChainPolicy) != 0)
299 result = 0x800B010B; // TRUST_E_FAIL - generic
301 break; // Exit the loop on the first error
306 static SslPolicyErrors GetErrorsFromChain (X509Chain chain)
308 SslPolicyErrors errors = SslPolicyErrors.None;
309 foreach (var status in chain.ChainStatus) {
310 if (status.Status == X509ChainStatusFlags.NoError)
312 errors |= SslPolicyErrors.RemoteCertificateChainErrors;
320 static X509KeyUsageFlags s_flags = X509KeyUsageFlags.DigitalSignature |
321 X509KeyUsageFlags.KeyAgreement |
322 X509KeyUsageFlags.KeyEncipherment;
323 // Adapted to System 2.0+ from TlsServerCertificate.cs
324 //------------------------------
325 // Note: this method only works for RSA certificates
326 // DH certificates requires some changes - does anyone use one ?
327 static bool CheckCertificateUsage (X509Certificate2 cert)
330 // certificate extensions are required for this
331 // we "must" accept older certificates without proofs
332 if (cert.Version < 3)
335 X509KeyUsageExtension kux = (cert.Extensions ["2.5.29.15"] as X509KeyUsageExtension);
336 X509EnhancedKeyUsageExtension eku = (cert.Extensions ["2.5.29.37"] as X509EnhancedKeyUsageExtension);
337 if (kux != null && eku != null) {
338 // RFC3280 states that when both KeyUsageExtension and
339 // ExtendedKeyUsageExtension are present then BOTH should
341 if ((kux.KeyUsages & s_flags) == 0)
343 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
344 eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
345 } else if (kux != null) {
346 return ((kux.KeyUsages & s_flags) != 0);
347 } else if (eku != null) {
348 // Server Authentication (1.3.6.1.5.5.7.3.1) or
349 // Netscape Server Gated Crypto (2.16.840.1.113730.4)
350 return eku.EnhancedKeyUsages ["1.3.6.1.5.5.7.3.1"] != null ||
351 eku.EnhancedKeyUsages ["2.16.840.1.113730.4.1"] != null;
354 // last chance - try with older (deprecated) Netscape extensions
355 X509Extension ext = cert.Extensions ["2.16.840.1.113730.1.1"];
357 string text = ext.NetscapeCertType (false);
358 return text.IndexOf ("SSL Server Authentication", StringComparison.Ordinal) != -1;
361 } catch (Exception e) {
362 Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
363 Console.Error.WriteLine ("Please, report this problem to the Mono team");
368 // RFC2818 - HTTP Over TLS, Section 3.1
369 // http://www.ietf.org/rfc/rfc2818.txt
371 // 1. if present MUST use subjectAltName dNSName as identity
372 // 1.1. if multiples entries a match of any one is acceptable
373 // 1.2. wildcard * is acceptable
374 // 2. URI may be an IP address -> subjectAltName.iPAddress
375 // 2.1. exact match is required
376 // 3. Use of the most specific Common Name (CN=) in the Subject
377 // 3.1 Existing practice but DEPRECATED
378 static bool CheckServerIdentity (X509Certificate2 cert, string targetHost)
381 var mcert = new MSX.X509Certificate (cert.RawData);
382 MSX.X509Extension ext = mcert.Extensions ["2.5.29.17"];
385 SubjectAltNameExtension subjectAltName = new SubjectAltNameExtension (ext);
386 // 1.1 - multiple dNSName
387 foreach (string dns in subjectAltName.DNSNames) {
388 // 1.2 TODO - wildcard support
389 if (Match (targetHost, dns))
393 foreach (string ip in subjectAltName.IPAddresses) {
394 // 2.1. Exact match required
395 if (ip == targetHost)
399 // 3. Common Name (CN=)
400 return CheckDomainName (mcert.SubjectName, targetHost);
401 } catch (Exception e) {
402 Console.Error.WriteLine ("ERROR processing certificate: {0}", e);
403 Console.Error.WriteLine ("Please, report this problem to the Mono team");
408 static bool CheckDomainName (string subjectName, string targetHost)
410 string domainName = String.Empty;
411 Regex search = new Regex (@"CN\s*=\s*([^,]*)");
412 MatchCollection elements = search.Matches (subjectName);
413 if (elements.Count == 1) {
414 if (elements [0].Success)
415 domainName = elements [0].Groups [1].Value.ToString ();
418 return Match (targetHost, domainName);
421 // ensure the pattern is valid wrt to RFC2595 and RFC2818
422 // http://www.ietf.org/rfc/rfc2595.txt
423 // http://www.ietf.org/rfc/rfc2818.txt
424 static bool Match (string hostname, string pattern)
426 // check if this is a pattern
427 int index = pattern.IndexOf ('*');
429 // not a pattern, do a direct case-insensitive comparison
430 return (String.Compare (hostname, pattern, true, CultureInfo.InvariantCulture) == 0);
433 // check pattern validity
434 // A "*" wildcard character MAY be used as the left-most name component in the certificate.
436 // unless this is the last char (valid)
437 if (index != pattern.Length - 1) {
438 // then the next char must be a dot .'.
439 if (pattern [index + 1] != '.')
443 // only one (A) wildcard is supported
444 int i2 = pattern.IndexOf ('*', index + 1);
448 // match the end of the pattern
449 string end = pattern.Substring (index + 1);
450 int length = hostname.Length - end.Length;
451 // no point to check a pattern that is longer than the hostname
455 if (String.Compare (hostname, length, end, 0, end.Length, true, CultureInfo.InvariantCulture) != 0)
458 // special case, we start with the wildcard
460 // ensure we hostname non-matched part (start) doesn't contain a dot
461 int i3 = hostname.IndexOf ('.');
462 return ((i3 == -1) || (i3 >= (hostname.Length - end.Length)));
465 // match the start of the pattern
466 string start = pattern.Substring (0, index);
467 return (String.Compare (hostname, 0, start, 0, start.Length, true, CultureInfo.InvariantCulture) == 0);