src/qt/paymentrequestplus.cpp

   1 // Copyright (c) 2011-2016 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 //
   6 // Wraps dumb protocol buffer paymentRequest
   7 // with some extra methods
   8 //
   9
  10 #include "paymentrequestplus.h"
  11
  12 #include "util.h"
  13
  14 #include <stdexcept>
  15
  16 #include <openssl/x509_vfy.h>
  17
  18 #include <QDateTime>
  19 #include <QDebug>
  20 #include <QSslCertificate>
  21
  22 class SSLVerifyError : public std::runtime_error
  23 {
  24 public:
  25     SSLVerifyError(std::string err) : std::runtime_error(err) { }
  26 };
  27
  28 bool PaymentRequestPlus::parse(const QByteArray& data)
  29 {
  30     bool parseOK = paymentRequest.ParseFromArray(data.data(), data.size());
  31     if (!parseOK) {
  32         qWarning() << "PaymentRequestPlus::parse: Error parsing payment request";
  33         return false;
  34     }
  35     if (paymentRequest.payment_details_version() > 1) {
  36         qWarning() << "PaymentRequestPlus::parse: Received up-version payment details, version=" << paymentRequest.payment_details_version();
  37         return false;
  38     }
  39
  40     parseOK = details.ParseFromString(paymentRequest.serialized_payment_details());
  41     if (!parseOK)
  42     {
  43         qWarning() << "PaymentRequestPlus::parse: Error parsing payment details";
  44         paymentRequest.Clear();
  45         return false;
  46     }
  47     return true;
  48 }
  49
  50 bool PaymentRequestPlus::SerializeToString(std::string* output) const
  51 {
  52     return paymentRequest.SerializeToString(output);
  53 }
  54
  55 bool PaymentRequestPlus::IsInitialized() const
  56 {
  57     return paymentRequest.IsInitialized();
  58 }
  59
  60 bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) const
  61 {
  62     merchant.clear();
  63
  64     if (!IsInitialized())
  65         return false;
  66
  67     // One day we'll support more PKI types, but just
  68     // x509 for now:
  69     const EVP_MD* digestAlgorithm = nullptr;
  70     if (paymentRequest.pki_type() == "x509+sha256") {
  71         digestAlgorithm = EVP_sha256();
  72     }
  73     else if (paymentRequest.pki_type() == "x509+sha1") {
  74         digestAlgorithm = EVP_sha1();
  75     }
  76     else if (paymentRequest.pki_type() == "none") {
  77         qWarning() << "PaymentRequestPlus::getMerchant: Payment request: pki_type == none";
  78         return false;
  79     }
  80     else {
  81         qWarning() << "PaymentRequestPlus::getMerchant: Payment request: unknown pki_type " << QString::fromStdString(paymentRequest.pki_type());
  82         return false;
  83     }
  84
  85     payments::X509Certificates certChain;
  86     if (!certChain.ParseFromString(paymentRequest.pki_data())) {
  87         qWarning() << "PaymentRequestPlus::getMerchant: Payment request: error parsing pki_data";
  88         return false;
  89     }
  90
  91     std::vector<X509*> certs;
  92     const QDateTime currentTime = QDateTime::currentDateTime();
  93     for (int i = 0; i < certChain.certificate_size(); i++) {
  94         QByteArray certData(certChain.certificate(i).data(), certChain.certificate(i).size());
  95         QSslCertificate qCert(certData, QSsl::Der);
  96         if (currentTime < qCert.effectiveDate() || currentTime > qCert.expiryDate()) {
  97             qWarning() << "PaymentRequestPlus::getMerchant: Payment request: certificate expired or not yet active: " << qCert;
  98             return false;
  99         }
 100 #if QT_VERSION >= 0x050000
 101         if (qCert.isBlacklisted()) {
 102             qWarning() << "PaymentRequestPlus::getMerchant: Payment request: certificate blacklisted: " << qCert;
 103             return false;
 104         }
 105 #endif
 106         const unsigned char *data = (const unsigned char *)certChain.certificate(i).data();
 107         X509 *cert = d2i_X509(nullptr, &data, certChain.certificate(i).size());
 108         if (cert)
 109             certs.push_back(cert);
 110     }
 111     if (certs.empty()) {
 112         qWarning() << "PaymentRequestPlus::getMerchant: Payment request: empty certificate chain";
 113         return false;
 114     }
 115
 116     // The first cert is the signing cert, the rest are untrusted certs that chain
 117     // to a valid root authority. OpenSSL needs them separately.
 118     STACK_OF(X509) *chain = sk_X509_new_null();
 119     for (int i = certs.size() - 1; i > 0; i--) {
 120         sk_X509_push(chain, certs[i]);
 121     }
 122     X509 *signing_cert = certs[0];
 123
 124     // Now create a "store context", which is a single use object for checking,
 125     // load the signing cert into it and verify.
 126     X509_STORE_CTX *store_ctx = X509_STORE_CTX_new();
 127     if (!store_ctx) {
 128         qWarning() << "PaymentRequestPlus::getMerchant: Payment request: error creating X509_STORE_CTX";
 129         return false;
 130     }
 131
 132     char *website = nullptr;
 133     bool fResult = true;
 134     try
 135     {
 136         if (!X509_STORE_CTX_init(store_ctx, certStore, signing_cert, chain))
 137         {
 138             int error = X509_STORE_CTX_get_error(store_ctx);
 139             throw SSLVerifyError(X509_verify_cert_error_string(error));
 140         }
 141
 142         // Now do the verification!
 143         int result = X509_verify_cert(store_ctx);
 144         if (result != 1) {
 145             int error = X509_STORE_CTX_get_error(store_ctx);
 146             // For testing payment requests, we allow self signed root certs!
 147             // This option is just shown in the UI options, if -help-debug is enabled.
 148             if (!(error == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT && gArgs.GetBoolArg("-allowselfsignedrootcertificates", DEFAULT_SELFSIGNED_ROOTCERTS))) {
 149                 throw SSLVerifyError(X509_verify_cert_error_string(error));
 150             } else {
 151                qDebug() << "PaymentRequestPlus::getMerchant: Allowing self signed root certificate, because -allowselfsignedrootcertificates is true.";
 152             }
 153         }
 154         X509_NAME *certname = X509_get_subject_name(signing_cert);
 155
 156         // Valid cert; check signature:
 157         payments::PaymentRequest rcopy(paymentRequest); // Copy
 158         rcopy.set_signature(std::string(""));
 159         std::string data_to_verify;                     // Everything but the signature
 160         rcopy.SerializeToString(&data_to_verify);
 161
 162 #if HAVE_DECL_EVP_MD_CTX_NEW
 163         EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 164         if (!ctx) throw SSLVerifyError("Error allocating OpenSSL context.");
 165 #else
 166         EVP_MD_CTX _ctx;
 167         EVP_MD_CTX *ctx;
 168         ctx = &_ctx;
 169 #endif
 170         EVP_PKEY *pubkey = X509_get_pubkey(signing_cert);
 171         EVP_MD_CTX_init(ctx);
 172         if (!EVP_VerifyInit_ex(ctx, digestAlgorithm, nullptr) ||
 173             !EVP_VerifyUpdate(ctx, data_to_verify.data(), data_to_verify.size()) ||
 174             !EVP_VerifyFinal(ctx, (const unsigned char*)paymentRequest.signature().data(), (unsigned int)paymentRequest.signature().size(), pubkey)) {
 175             throw SSLVerifyError("Bad signature, invalid payment request.");
 176         }
 177 #if HAVE_DECL_EVP_MD_CTX_NEW
 178         EVP_MD_CTX_free(ctx);
 179 #endif
 180
 181         // OpenSSL API for getting human printable strings from certs is baroque.
 182         int textlen = X509_NAME_get_text_by_NID(certname, NID_commonName, nullptr, 0);
 183         website = new char[textlen + 1];
 184         if (X509_NAME_get_text_by_NID(certname, NID_commonName, website, textlen + 1) == textlen && textlen > 0) {
 185             merchant = website;
 186         }
 187         else {
 188             throw SSLVerifyError("Bad certificate, missing common name.");
 189         }
 190         // TODO: detect EV certificates and set merchant = business name instead of unfriendly NID_commonName ?
 191     }
 192     catch (const SSLVerifyError& err) {
 193         fResult = false;
 194         qWarning() << "PaymentRequestPlus::getMerchant: SSL error: " << err.what();
 195     }
 196
 197     delete[] website;
 198     X509_STORE_CTX_free(store_ctx);
 199     for (unsigned int i = 0; i < certs.size(); i++)
 200         X509_free(certs[i]);
 201
 202     return fResult;
 203 }
 204
 205 QList<std::pair<CScript,CAmount> > PaymentRequestPlus::getPayTo() const
 206 {
 207     QList<std::pair<CScript,CAmount> > result;
 208     for (int i = 0; i < details.outputs_size(); i++)
 209     {
 210         const unsigned char* scriptStr = (const unsigned char*)details.outputs(i).script().data();
 211         CScript s(scriptStr, scriptStr+details.outputs(i).script().size());
 212
 213         result.append(std::make_pair(s, details.outputs(i).amount()));
 214     }
 215     return result;
 216 }