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/x509_certificate.h"
  22
  23 namespace net {
  24
  25 namespace {
  26
  27 // Maps X509_STORE_CTX_get_error() return values to our cert status flags.
  28 CertStatus MapCertErrorToCertStatus(int err) {
  29   switch (err) {
  30     case X509_V_ERR_SUBJECT_ISSUER_MISMATCH:
  31       return CERT_STATUS_COMMON_NAME_INVALID;
  32     case X509_V_ERR_CERT_NOT_YET_VALID:
  33     case X509_V_ERR_CERT_HAS_EXPIRED:
  34     case X509_V_ERR_CRL_NOT_YET_VALID:
  35     case X509_V_ERR_CRL_HAS_EXPIRED:
  36     case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
  37     case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
  38     case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
  39     case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
  40       return CERT_STATUS_DATE_INVALID;
  41     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
  42     case X509_V_ERR_UNABLE_TO_GET_CRL:
  43     case X509_V_ERR_INVALID_CA:
  44     case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
  45     case X509_V_ERR_INVALID_NON_CA:
  46     case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
  47     case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
  48     case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
  49       return CERT_STATUS_AUTHORITY_INVALID;
  50 #if 0
  51 // TODO(bulach): what should we map to these status?
  52       return CERT_STATUS_NO_REVOCATION_MECHANISM;
  53       return CERT_STATUS_UNABLE_TO_CHECK_REVOCATION;
  54 #endif
  55     case X509_V_ERR_CERT_REVOKED:
  56       return CERT_STATUS_REVOKED;
  57     // All these status are mapped to CERT_STATUS_INVALID.
  58     case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
  59     case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
  60     case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
  61     case X509_V_ERR_CERT_SIGNATURE_FAILURE:
  62     case X509_V_ERR_CRL_SIGNATURE_FAILURE:
  63     case X509_V_ERR_OUT_OF_MEM:
  64     case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
  65     case X509_V_ERR_CERT_CHAIN_TOO_LONG:
  66     case X509_V_ERR_PATH_LENGTH_EXCEEDED:
  67     case X509_V_ERR_INVALID_PURPOSE:
  68     case X509_V_ERR_CERT_UNTRUSTED:
  69     case X509_V_ERR_CERT_REJECTED:
  70     case X509_V_ERR_AKID_SKID_MISMATCH:
  71     case X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH:
  72     case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:
  73     case X509_V_ERR_KEYUSAGE_NO_CERTSIGN:
  74     case X509_V_ERR_KEYUSAGE_NO_CRL_SIGN:
  75     case X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION:
  76     case X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED:
  77     case X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE:
  78     case X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED:
  79     case X509_V_ERR_INVALID_EXTENSION:
  80     case X509_V_ERR_INVALID_POLICY_EXTENSION:
  81     case X509_V_ERR_NO_EXPLICIT_POLICY:
  82     case X509_V_ERR_UNNESTED_RESOURCE:
  83     case X509_V_ERR_APPLICATION_VERIFICATION:
  84       return CERT_STATUS_INVALID;
  85     default:
  86       NOTREACHED() << "Invalid X509 err " << err;
  87       return CERT_STATUS_INVALID;
  88   }
  89 }
  90
  91 // sk_X509_free is a function-style macro, so can't be used as a template
  92 // param directly.
  93 void sk_X509_free_fn(STACK_OF(X509)* st) {
  94   sk_X509_free(st);
  95 }
  96
  97 void GetCertChainInfo(X509_STORE_CTX* store_ctx,
  98                       CertVerifyResult* verify_result) {
  99   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 100   X509* verified_cert = NULL;
 101   std::vector<X509*> verified_chain;
 102   for (int i = 0; i < sk_X509_num(chain); ++i) {
 103     X509* cert = sk_X509_value(chain, i);
 104     if (i == 0) {
 105       verified_cert = cert;
 106     } else {
 107       verified_chain.push_back(cert);
 108     }
 109
 110     // Only check the algorithm status for certificates that are not in the
 111     // trust store.
 112     if (i < store_ctx->last_untrusted) {
 113       int sig_alg = OBJ_obj2nid(cert->sig_alg->algorithm);
 114       if (sig_alg == NID_md2WithRSAEncryption) {
 115         verify_result->has_md2 = true;
 116       } else if (sig_alg == NID_md4WithRSAEncryption) {
 117         verify_result->has_md4 = true;
 118       } else if (sig_alg == NID_md5WithRSAEncryption) {
 119         verify_result->has_md5 = true;
 120       }
 121     }
 122   }
 123
 124   if (verified_cert) {
 125     verify_result->verified_cert =
 126         X509Certificate::CreateFromHandle(verified_cert, verified_chain);
 127   }
 128 }
 129
 130 void AppendPublicKeyHashes(X509_STORE_CTX* store_ctx,
 131                            HashValueVector* hashes) {
 132   STACK_OF(X509)* chain = X509_STORE_CTX_get_chain(store_ctx);
 133   for (int i = 0; i < sk_X509_num(chain); ++i) {
 134     X509* cert = sk_X509_value(chain, i);
 135
 136     std::string der_data;
 137     if (!X509Certificate::GetDEREncoded(cert, &der_data))
 138       continue;
 139
 140     base::StringPiece der_bytes(der_data);
 141     base::StringPiece spki_bytes;
 142     if (!asn1::ExtractSPKIFromDERCert(der_bytes, &spki_bytes))
 143       continue;
 144
 145     HashValue sha1(HASH_VALUE_SHA1);
 146     base::SHA1HashBytes(reinterpret_cast<const uint8*>(spki_bytes.data()),
 147                         spki_bytes.size(), sha1.data());
 148     hashes->push_back(sha1);
 149
 150     HashValue sha256(HASH_VALUE_SHA256);
 151     crypto::SHA256HashString(spki_bytes, sha256.data(), crypto::kSHA256Length);
 152     hashes->push_back(sha256);
 153   }
 154 }
 155
 156 }  // namespace
 157
 158 CertVerifyProcOpenSSL::CertVerifyProcOpenSSL() {}
 159
 160 CertVerifyProcOpenSSL::~CertVerifyProcOpenSSL() {}
 161
 162 bool CertVerifyProcOpenSSL::SupportsAdditionalTrustAnchors() const {
 163   return false;
 164 }
 165
 166 int CertVerifyProcOpenSSL::VerifyInternal(
 167     X509Certificate* cert,
 168     const std::string& hostname,
 169     int flags,
 170     CRLSet* crl_set,
 171     const CertificateList& additional_trust_anchors,
 172     CertVerifyResult* verify_result) {
 173   crypto::EnsureOpenSSLInit();
 174
 175   if (!cert->VerifyNameMatch(hostname))
 176     verify_result->cert_status |= CERT_STATUS_COMMON_NAME_INVALID;
 177
 178   crypto::ScopedOpenSSL<X509_STORE_CTX, X509_STORE_CTX_free> ctx(
 179       X509_STORE_CTX_new());
 180
 181   crypto::ScopedOpenSSL<STACK_OF(X509), sk_X509_free_fn> intermediates(
 182       sk_X509_new_null());
 183   if (!intermediates.get())
 184     return ERR_OUT_OF_MEMORY;
 185
 186   const X509Certificate::OSCertHandles& os_intermediates =
 187       cert->GetIntermediateCertificates();
 188   for (X509Certificate::OSCertHandles::const_iterator it =
 189        os_intermediates.begin(); it != os_intermediates.end(); ++it) {
 190     if (!sk_X509_push(intermediates.get(), *it))
 191       return ERR_OUT_OF_MEMORY;
 192   }
 193   if (X509_STORE_CTX_init(ctx.get(), X509Certificate::cert_store(),
 194                           cert->os_cert_handle(), intermediates.get()) != 1) {
 195     NOTREACHED();
 196     return ERR_FAILED;
 197   }
 198
 199   if (X509_verify_cert(ctx.get()) != 1) {
 200     int x509_error = X509_STORE_CTX_get_error(ctx.get());
 201     CertStatus cert_status = MapCertErrorToCertStatus(x509_error);
 202     LOG(ERROR) << "X509 Verification error "
 203         << X509_verify_cert_error_string(x509_error)
 204         << " : " << x509_error
 205         << " : " << X509_STORE_CTX_get_error_depth(ctx.get())
 206         << " : " << cert_status;
 207     verify_result->cert_status |= cert_status;
 208   }
 209
 210   GetCertChainInfo(ctx.get(), verify_result);
 211   AppendPublicKeyHashes(ctx.get(), &verify_result->public_key_hashes);
 212   if (IsCertStatusError(verify_result->cert_status))
 213     return MapCertStatusToNetError(verify_result->cert_status);
 214
 215   // Currently we only ues OpenSSL's default root CA paths, so treat all
 216   // correctly verified certs as being from a known root.
 217   // TODO(joth): if the motivations described in
 218   // http://src.chromium.org/viewvc/chrome?view=rev&revision=80778 become an
 219   // issue on OpenSSL builds, we will need to embed a hardcoded list of well
 220   // known root CAs, as per the _mac and _win versions.
 221   verify_result->is_issued_by_known_root = true;
 222
 223   return OK;
 224 }
 225
 226 }  // namespace net