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/sha2.h"
  16 #include "net/base/net_errors.h"
  17 #include "net/cert/asn1_util.h"
  18 #include "net/cert/cert_status_flags.h"
  19 #include "net/cert/cert_verifier.h"
  20 #include "net/cert/cert_verify_result.h"
  21 #include "net/cert/test_root_certs.h"
  22 #include "net/cert/x509_certificate.h"
  23
  24 namespace net {
  25
  26 namespace {
  27
  28 // Maps X509_STORE_CTX_get_error() return values to our cert status flags.
  29 CertStatus MapCertErrorToCertStatus(int err) {
  30   switch (err) {
  31     case X509_V_ERR_SUBJECT_ISSUER_MISMATCH:
  32       return CERT_STATUS_COMMON_NAME_INVALID;
  33     case X509_V_ERR_CERT_NOT_YET_VALID:
  34     case X509_V_ERR_CERT_HAS_EXPIRED:
  35     case X509_V_ERR_CRL_NOT_YET_VALID:
  36     case X509_V_ERR_CRL_HAS_EXPIRED:
  37     case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
  38     case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
  39     case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
  40     case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
  41       return CERT_STATUS_DATE_INVALID;
  42     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
  43     case X509_V_ERR_UNABLE_TO_GET_CRL:
  44     case X509_V_ERR_INVALID_CA:
  45     case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
  46     case X509_V_ERR_INVALID_NON_CA:
  47     case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
  48     case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
  49     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
  50       return CERT_STATUS_AUTHORITY_INVALID;
  51 #if 0
  52 // TODO(bulach): what should we map to these status?
  53       return CERT_STATUS_NO_REVOCATION_MECHANISM;
  54       return CERT_STATUS_UNABLE_TO_CHECK_REVOCATION;
  55 #endif
  56     case X509_V_ERR_CERT_REVOKED:
  57       return CERT_STATUS_REVOKED;
  58     // All these status are mapped to CERT_STATUS_INVALID.
  59     case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
  60     case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
  61     case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
  62     case X509_V_ERR_CERT_SIGNATURE_FAILURE:
  63     case X509_V_ERR_CRL_SIGNATURE_FAILURE:
  64     case X509_V_ERR_OUT_OF_MEM:
  65     case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
  66     case X509_V_ERR_CERT_CHAIN_TOO_LONG:
  67     case X509_V_ERR_PATH_LENGTH_EXCEEDED:
  68     case X509_V_ERR_INVALID_PURPOSE:
  69     case X509_V_ERR_CERT_UNTRUSTED:
  70     case X509_V_ERR_CERT_REJECTED:
  71     case X509_V_ERR_AKID_SKID_MISMATCH:
  72     case X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH:
  73     case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:
  74     case X509_V_ERR_KEYUSAGE_NO_CERTSIGN:
  75     case X509_V_ERR_KEYUSAGE_NO_CRL_SIGN:
  76     case X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION:
  77     case X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED:
  78     case X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE:
  79     case X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED:
  80     case X509_V_ERR_INVALID_EXTENSION:
  81     case X509_V_ERR_INVALID_POLICY_EXTENSION:
  82     case X509_V_ERR_NO_EXPLICIT_POLICY:
  83     case X509_V_ERR_UNNESTED_RESOURCE:
  84     case X509_V_ERR_APPLICATION_VERIFICATION:
  85       return CERT_STATUS_INVALID;
  86     default:
  87       NOTREACHED() << "Invalid X509 err " << err;
  88       return CERT_STATUS_INVALID;
  89   }
  90 }
  91
  92 // sk_X509_free is a function-style macro, so can't be used as a template
  93 // param directly.
  94 void sk_X509_free_fn(STACK_OF(X509)* st) {
  95   sk_X509_free(st);
  96 }
  97
  98 void GetCertChainInfo(X509_STORE_CTX* store_ctx,
  99                       CertVerifyResult* verify_result) {
 100   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 101   X509* verified_cert = NULL;
 102   std::vector<X509*> verified_chain;
 103   for (int i = 0; i < sk_X509_num(chain); ++i) {
 104     X509* cert = sk_X509_value(chain, i);
 105     if (i == 0) {
 106       verified_cert = cert;
 107     } else {
 108       verified_chain.push_back(cert);
 109     }
 110
 111     // Only check the algorithm status for certificates that are not in the
 112     // trust store.
 113     if (i < store_ctx->last_untrusted) {
 114       int sig_alg = OBJ_obj2nid(cert->sig_alg->algorithm);
 115       if (sig_alg == NID_md2WithRSAEncryption) {
 116         verify_result->has_md2 = true;
 117       } else if (sig_alg == NID_md4WithRSAEncryption) {
 118         verify_result->has_md4 = true;
 119       } else if (sig_alg == NID_md5WithRSAEncryption) {
 120         verify_result->has_md5 = true;
 121       }
 122     }
 123   }
 124
 125   // Set verify_result->verified_cert and
 126   // verify_result->is_issued_by_known_root.
 127   if (verified_cert) {
 128     verify_result->verified_cert =
 129         X509Certificate::CreateFromHandle(verified_cert, verified_chain);
 130
 131     // For OpenSSL builds, only certificates used for unit tests are treated
 132     // as not issued by known roots. The only way to determine whether a
 133     // certificate is issued by a known root using OpenSSL is to examine
 134     // distro-and-release specific hardcoded lists.
 135     verify_result->is_issued_by_known_root = true;
 136     if (TestRootCerts::HasInstance()) {
 137       X509* root = NULL;
 138       if (verified_chain.empty()) {
 139         root = verified_cert;
 140       } else {
 141         root = verified_chain.back();
 142       }
 143       TestRootCerts* root_certs = TestRootCerts::GetInstance();
 144       if (root_certs->Contains(root))
 145           verify_result->is_issued_by_known_root = false;
 146     }
 147   }
 148 }
 149
 150 void AppendPublicKeyHashes(X509_STORE_CTX* store_ctx,
 151                            HashValueVector* hashes) {
 152   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 153   for (int i = 0; i < sk_X509_num(chain); ++i) {
 154     X509* cert = sk_X509_value(chain, i);
 155
 156     std::string der_data;
 157     if (!X509Certificate::GetDEREncoded(cert, &der_data))
 158       continue;
 159
 160     base::StringPiece der_bytes(der_data);
 161     base::StringPiece spki_bytes;
 162     if (!asn1::ExtractSPKIFromDERCert(der_bytes, &spki_bytes))
 163       continue;
 164
 165     HashValue sha1(HASH_VALUE_SHA1);
 166     base::SHA1HashBytes(reinterpret_cast<const uint8*>(spki_bytes.data()),
 167                         spki_bytes.size(), sha1.data());
 168     hashes->push_back(sha1);
 169
 170     HashValue sha256(HASH_VALUE_SHA256);
 171     crypto::SHA256HashString(spki_bytes, sha256.data(), crypto::kSHA256Length);
 172     hashes->push_back(sha256);
 173   }
 174 }
 175
 176 }  // namespace
 177
 178 CertVerifyProcOpenSSL::CertVerifyProcOpenSSL() {}
 179
 180 CertVerifyProcOpenSSL::~CertVerifyProcOpenSSL() {}
 181
 182 bool CertVerifyProcOpenSSL::SupportsAdditionalTrustAnchors() const {
 183   return false;
 184 }
 185
 186 int CertVerifyProcOpenSSL::VerifyInternal(
 187     X509Certificate* cert,
 188     const std::string& hostname,
 189     int flags,
 190     CRLSet* crl_set,
 191     const CertificateList& additional_trust_anchors,
 192     CertVerifyResult* verify_result) {
 193   crypto::EnsureOpenSSLInit();
 194
 195   if (!cert->VerifyNameMatch(hostname,
 196                              &verify_result->common_name_fallback_used)) {
 197     verify_result->cert_status |= CERT_STATUS_COMMON_NAME_INVALID;
 198   }
 199
 200   crypto::ScopedOpenSSL<X509_STORE_CTX, X509_STORE_CTX_free> ctx(
 201       X509_STORE_CTX_new());
 202
 203   crypto::ScopedOpenSSL<STACK_OF(X509), sk_X509_free_fn> intermediates(
 204       sk_X509_new_null());
 205   if (!intermediates.get())
 206     return ERR_OUT_OF_MEMORY;
 207
 208   const X509Certificate::OSCertHandles& os_intermediates =
 209       cert->GetIntermediateCertificates();
 210   for (X509Certificate::OSCertHandles::const_iterator it =
 211        os_intermediates.begin(); it != os_intermediates.end(); ++it) {
 212     if (!sk_X509_push(intermediates.get(), *it))
 213       return ERR_OUT_OF_MEMORY;
 214   }
 215   if (X509_STORE_CTX_init(ctx.get(), X509Certificate::cert_store(),
 216                           cert->os_cert_handle(), intermediates.get()) != 1) {
 217     NOTREACHED();
 218     return ERR_FAILED;
 219   }
 220
 221   if (X509_verify_cert(ctx.get()) != 1) {
 222     int x509_error = X509_STORE_CTX_get_error(ctx.get());
 223     CertStatus cert_status = MapCertErrorToCertStatus(x509_error);
 224     LOG(ERROR) << "X509 Verification error "
 225         << X509_verify_cert_error_string(x509_error)
 226         << " : " << x509_error
 227         << " : " << X509_STORE_CTX_get_error_depth(ctx.get())
 228         << " : " << cert_status;
 229     verify_result->cert_status |= cert_status;
 230   }
 231
 232   GetCertChainInfo(ctx.get(), verify_result);
 233   AppendPublicKeyHashes(ctx.get(), &verify_result->public_key_hashes);
 234   if (IsCertStatusError(verify_result->cert_status))
 235     return MapCertStatusToNetError(verify_result->cert_status);
 236
 237   return OK;
 238 }
 239
 240 }  // namespace net