net/cert/cert_verify_proc_openssl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/cert/cert_verify_proc_openssl.h"
   6
   7 #include <openssl/x509v3.h>
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/logging.h"
  13 #include "base/sha1.h"
  14 #include "crypto/openssl_util.h"
  15 #include "crypto/scoped_openssl_types.h"
  16 #include "crypto/sha2.h"
  17 #include "net/base/net_errors.h"
  18 #include "net/cert/asn1_util.h"
  19 #include "net/cert/cert_status_flags.h"
  20 #include "net/cert/cert_verifier.h"
  21 #include "net/cert/cert_verify_result.h"
  22 #include "net/cert/test_root_certs.h"
  23 #include "net/cert/x509_certificate.h"
  24
  25 namespace net {
  26
  27 namespace {
  28
  29 // Maps X509_STORE_CTX_get_error() return values to our cert status flags.
  30 CertStatus MapCertErrorToCertStatus(int err) {
  31   switch (err) {
  32     case X509_V_ERR_SUBJECT_ISSUER_MISMATCH:
  33       return CERT_STATUS_COMMON_NAME_INVALID;
  34     case X509_V_ERR_CERT_NOT_YET_VALID:
  35     case X509_V_ERR_CERT_HAS_EXPIRED:
  36     case X509_V_ERR_CRL_NOT_YET_VALID:
  37     case X509_V_ERR_CRL_HAS_EXPIRED:
  38     case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
  39     case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
  40     case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
  41     case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
  42       return CERT_STATUS_DATE_INVALID;
  43     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
  44     case X509_V_ERR_UNABLE_TO_GET_CRL:
  45     case X509_V_ERR_INVALID_CA:
  46     case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
  47     case X509_V_ERR_INVALID_NON_CA:
  48     case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
  49     case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
  50     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
  51       return CERT_STATUS_AUTHORITY_INVALID;
  52 #if 0
  53 // TODO(bulach): what should we map to these status?
  54       return CERT_STATUS_NO_REVOCATION_MECHANISM;
  55       return CERT_STATUS_UNABLE_TO_CHECK_REVOCATION;
  56 #endif
  57     case X509_V_ERR_CERT_REVOKED:
  58       return CERT_STATUS_REVOKED;
  59     // All these status are mapped to CERT_STATUS_INVALID.
  60     case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
  61     case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
  62     case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
  63     case X509_V_ERR_CERT_SIGNATURE_FAILURE:
  64     case X509_V_ERR_CRL_SIGNATURE_FAILURE:
  65     case X509_V_ERR_OUT_OF_MEM:
  66     case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
  67     case X509_V_ERR_CERT_CHAIN_TOO_LONG:
  68     case X509_V_ERR_PATH_LENGTH_EXCEEDED:
  69     case X509_V_ERR_INVALID_PURPOSE:
  70     case X509_V_ERR_CERT_UNTRUSTED:
  71     case X509_V_ERR_CERT_REJECTED:
  72     case X509_V_ERR_AKID_SKID_MISMATCH:
  73     case X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH:
  74     case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:
  75     case X509_V_ERR_KEYUSAGE_NO_CERTSIGN:
  76     case X509_V_ERR_KEYUSAGE_NO_CRL_SIGN:
  77     case X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION:
  78     case X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED:
  79     case X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE:
  80     case X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED:
  81     case X509_V_ERR_INVALID_EXTENSION:
  82     case X509_V_ERR_INVALID_POLICY_EXTENSION:
  83     case X509_V_ERR_NO_EXPLICIT_POLICY:
  84     case X509_V_ERR_UNNESTED_RESOURCE:
  85     case X509_V_ERR_APPLICATION_VERIFICATION:
  86       return CERT_STATUS_INVALID;
  87     default:
  88       NOTREACHED() << "Invalid X509 err " << err;
  89       return CERT_STATUS_INVALID;
  90   }
  91 }
  92
  93 // sk_X509_free is a function-style macro, so can't be used as a template
  94 // param directly.
  95 void sk_X509_free_fn(STACK_OF(X509)* st) {
  96   sk_X509_free(st);
  97 }
  98
  99 void GetCertChainInfo(X509_STORE_CTX* store_ctx,
 100                       CertVerifyResult* verify_result) {
 101   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 102   X509* verified_cert = NULL;
 103   std::vector<X509*> verified_chain;
 104   for (size_t i = 0; i < sk_X509_num(chain); ++i) {
 105     X509* cert = sk_X509_value(chain, i);
 106     if (i == 0) {
 107       verified_cert = cert;
 108     } else {
 109       verified_chain.push_back(cert);
 110     }
 111
 112     // Only check the algorithm status for certificates that are not in the
 113     // trust store.
 114     if (i < static_cast<size_t>(store_ctx->last_untrusted)) {
 115       int sig_alg = OBJ_obj2nid(cert->sig_alg->algorithm);
 116       if (sig_alg == NID_md2WithRSAEncryption) {
 117         verify_result->has_md2 = true;
 118       } else if (sig_alg == NID_md4WithRSAEncryption) {
 119         verify_result->has_md4 = true;
 120       } else if (sig_alg == NID_md5WithRSAEncryption ||
 121                  sig_alg == NID_md5WithRSA) {
 122         verify_result->has_md5 = true;
 123       } else if (sig_alg == NID_sha1WithRSAEncryption ||
 124                  sig_alg == NID_dsaWithSHA || sig_alg == NID_dsaWithSHA1 ||
 125                  sig_alg == NID_dsaWithSHA1_2 || sig_alg == NID_sha1WithRSA ||
 126                  sig_alg == NID_ecdsa_with_SHA1) {
 127         verify_result->has_sha1 = true;
 128       }
 129     }
 130   }
 131
 132   // Set verify_result->verified_cert and
 133   // verify_result->is_issued_by_known_root.
 134   if (verified_cert) {
 135     verify_result->verified_cert =
 136         X509Certificate::CreateFromHandle(verified_cert, verified_chain);
 137
 138     // For OpenSSL builds, only certificates used for unit tests are treated
 139     // as not issued by known roots. The only way to determine whether a
 140     // certificate is issued by a known root using OpenSSL is to examine
 141     // distro-and-release specific hardcoded lists.
 142     verify_result->is_issued_by_known_root = true;
 143     if (TestRootCerts::HasInstance()) {
 144       X509* root = NULL;
 145       if (verified_chain.empty()) {
 146         root = verified_cert;
 147       } else {
 148         root = verified_chain.back();
 149       }
 150       TestRootCerts* root_certs = TestRootCerts::GetInstance();
 151       if (root_certs->Contains(root))
 152           verify_result->is_issued_by_known_root = false;
 153     }
 154   }
 155 }
 156
 157 void AppendPublicKeyHashes(X509_STORE_CTX* store_ctx,
 158                            HashValueVector* hashes) {
 159   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 160   for (size_t i = 0; i < sk_X509_num(chain); ++i) {
 161     X509* cert = sk_X509_value(chain, i);
 162
 163     std::string der_data;
 164     if (!X509Certificate::GetDEREncoded(cert, &der_data))
 165       continue;
 166
 167     base::StringPiece der_bytes(der_data);
 168     base::StringPiece spki_bytes;
 169     if (!asn1::ExtractSPKIFromDERCert(der_bytes, &spki_bytes))
 170       continue;
 171
 172     HashValue sha1(HASH_VALUE_SHA1);
 173     base::SHA1HashBytes(reinterpret_cast<const uint8_t*>(spki_bytes.data()),
 174                         spki_bytes.size(), sha1.data());
 175     hashes->push_back(sha1);
 176
 177     HashValue sha256(HASH_VALUE_SHA256);
 178     crypto::SHA256HashString(spki_bytes, sha256.data(), crypto::kSHA256Length);
 179     hashes->push_back(sha256);
 180   }
 181 }
 182
 183 }  // namespace
 184
 185 CertVerifyProcOpenSSL::CertVerifyProcOpenSSL() {}
 186
 187 CertVerifyProcOpenSSL::~CertVerifyProcOpenSSL() {}
 188
 189 bool CertVerifyProcOpenSSL::SupportsAdditionalTrustAnchors() const {
 190   return false;
 191 }
 192
 193 bool CertVerifyProcOpenSSL::SupportsOCSPStapling() const {
 194   return false;
 195 }
 196
 197 int CertVerifyProcOpenSSL::VerifyInternal(
 198     X509Certificate* cert,
 199     const std::string& hostname,
 200     const std::string& ocsp_response,
 201     int flags,
 202     CRLSet* crl_set,
 203     const CertificateList& additional_trust_anchors,
 204     CertVerifyResult* verify_result) {
 205   crypto::EnsureOpenSSLInit();
 206
 207   if (!cert->VerifyNameMatch(hostname,
 208                              &verify_result->common_name_fallback_used)) {
 209     verify_result->cert_status |= CERT_STATUS_COMMON_NAME_INVALID;
 210   }
 211
 212   crypto::ScopedOpenSSL<X509_STORE_CTX, X509_STORE_CTX_free> ctx(
 213       X509_STORE_CTX_new());
 214
 215   crypto::ScopedOpenSSL<STACK_OF(X509), sk_X509_free_fn> intermediates(
 216       sk_X509_new_null());
 217   if (!intermediates.get())
 218     return ERR_OUT_OF_MEMORY;
 219
 220   const X509Certificate::OSCertHandles& os_intermediates =
 221       cert->GetIntermediateCertificates();
 222   for (X509Certificate::OSCertHandles::const_iterator it =
 223        os_intermediates.begin(); it != os_intermediates.end(); ++it) {
 224     if (!sk_X509_push(intermediates.get(), *it))
 225       return ERR_OUT_OF_MEMORY;
 226   }
 227   if (X509_STORE_CTX_init(ctx.get(), X509Certificate::cert_store(),
 228                           cert->os_cert_handle(), intermediates.get()) != 1) {
 229     NOTREACHED();
 230     return ERR_FAILED;
 231   }
 232
 233   if (X509_verify_cert(ctx.get()) != 1) {
 234     int x509_error = X509_STORE_CTX_get_error(ctx.get());
 235     CertStatus cert_status = MapCertErrorToCertStatus(x509_error);
 236     LOG(ERROR) << "X509 Verification error "
 237         << X509_verify_cert_error_string(x509_error)
 238         << " : " << x509_error
 239         << " : " << X509_STORE_CTX_get_error_depth(ctx.get())
 240         << " : " << cert_status;
 241     verify_result->cert_status |= cert_status;
 242   }
 243
 244   GetCertChainInfo(ctx.get(), verify_result);
 245   AppendPublicKeyHashes(ctx.get(), &verify_result->public_key_hashes);
 246   if (IsCertStatusError(verify_result->cert_status))
 247     return MapCertStatusToNetError(verify_result->cert_status);
 248
 249   return OK;
 250 }
 251
 252 }  // namespace net