examples/common/chip-app-server/QRCodeUtil.cpp

   1 /*
   2  *
   3  *    Copyright (c) 2020 Project CHIP Authors
   4  *    All rights reserved.
   5  *
   6  *    Licensed under the Apache License, Version 2.0 (the "License");
   7  *    you may not use this file except in compliance with the License.
   8  *    You may obtain a copy of the License at
   9  *
  10  *        http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *    Unless required by applicable law or agreed to in writing, software
  13  *    distributed under the License is distributed on an "AS IS" BASIS,
  14  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *    See the License for the specific language governing permissions and
  16  *    limitations under the License.
  17  */
  18
  19 #include "QRCodeUtil.h"
  20
  21 #include <platform/CHIPDeviceLayer.h>
  22
  23 #include <setup_payload/QRCodeSetupPayloadGenerator.h>
  24 #include <support/CodeUtils.h>
  25 #include <support/ScopedBuffer.h>
  26 #include <support/logging/CHIPLogging.h>
  27
  28 constexpr char qrCodeBaseUrl[]                   = "https://dhrishi.github.io/connectedhomeip/qrcode.html";
  29 constexpr char specialCharsUnreservedInRfc3986[] = "-._~";
  30
  31 void PrintQRCode(chip::RendezvousInformationFlags rendezvousFlags)
  32 {
  33     uint32_t setupPinCode;
  34     std::string QRCode;
  35
  36     if (GetQRCode(setupPinCode, QRCode, rendezvousFlags) == CHIP_NO_ERROR)
  37     {
  38         ChipLogProgress(AppServer, "SetupPINCode: [%" PRIu32 "]", setupPinCode);
  39         ChipLogProgress(AppServer, "SetupQRCode:  [%s]", QRCode.c_str());
  40
  41         chip::Platform::ScopedMemoryBuffer<char> qrCodeBuffer;
  42         const size_t qrCodeBufferMaxSize = 3 * QRCode.size() + 1;
  43         qrCodeBuffer.Alloc(qrCodeBufferMaxSize);
  44         if (EncodeQRCodeToUrl(QRCode.c_str(), QRCode.size(), &qrCodeBuffer[0], qrCodeBufferMaxSize) == CHIP_NO_ERROR)
  45         {
  46             ChipLogProgress(AppServer, "Copy/paste the below URL in a browser to see the QR Code:\n\t%s?data=%s", qrCodeBaseUrl,
  47                             &qrCodeBuffer[0]);
  48         }
  49     }
  50     else
  51     {
  52         ChipLogError(AppServer, "Getting QR code failed!");
  53     }
  54 }
  55
  56 CHIP_ERROR GetQRCode(uint32_t & setupPinCode, std::string & QRCode, chip::RendezvousInformationFlags rendezvousFlags)
  57 {
  58     using namespace ::chip::DeviceLayer;
  59
  60     CHIP_ERROR err = CHIP_NO_ERROR;
  61     chip::SetupPayload payload;
  62
  63     payload.version               = 1;
  64     payload.rendezvousInformation = rendezvousFlags;
  65
  66     err = ConfigurationMgr().GetSetupPinCode(payload.setUpPINCode);
  67     VerifyOrExit(err == CHIP_NO_ERROR,
  68                  ChipLogProgress(AppServer, "ConfigurationMgr().GetSetupPinCode() failed: %s", chip::ErrorStr(err)));
  69     setupPinCode = payload.setUpPINCode;
  70
  71     err = ConfigurationMgr().GetSetupDiscriminator(payload.discriminator);
  72     VerifyOrExit(err == CHIP_NO_ERROR,
  73                  ChipLogProgress(AppServer, "ConfigurationMgr().GetSetupDiscriminator() failed: %s", chip::ErrorStr(err)));
  74
  75     err = ConfigurationMgr().GetVendorId(payload.vendorID);
  76     VerifyOrExit(err == CHIP_NO_ERROR,
  77                  ChipLogProgress(AppServer, "ConfigurationMgr().GetVendorId() failed: %s", chip::ErrorStr(err)));
  78
  79     err = ConfigurationMgr().GetProductId(payload.productID);
  80     VerifyOrExit(err == CHIP_NO_ERROR,
  81                  ChipLogProgress(AppServer, "ConfigurationMgr().GetProductId() failed: %s", chip::ErrorStr(err)));
  82
  83     // TODO: Usage of STL will significantly increase the image size, this should be changed to more efficient method for
  84     // generating payload
  85     err = chip::QRCodeSetupPayloadGenerator(payload).payloadBase41Representation(QRCode);
  86     VerifyOrExit(err == CHIP_NO_ERROR, ChipLogProgress(AppServer, "Generating QR Code failed: %s", chip::ErrorStr(err)));
  87
  88 exit:
  89     return err;
  90 }
  91
  92 static inline bool isCharUnreservedInRfc3986(const char c)
  93 {
  94     return isalpha(c) || isdigit(c) || (strchr(specialCharsUnreservedInRfc3986, c) != nullptr);
  95 }
  96
  97 CHIP_ERROR EncodeQRCodeToUrl(const char * QRCode, size_t len, char * url, size_t maxSize)
  98 {
  99     const char upperHexDigits[] = "0123456789ABCDEF";
 100     CHIP_ERROR err              = CHIP_NO_ERROR;
 101     size_t i = 0, j = 0;
 102
 103     VerifyOrExit((QRCode != nullptr) && (url != nullptr), err = CHIP_ERROR_INVALID_ARGUMENT);
 104
 105     for (i = 0; i < len; ++i)
 106     {
 107         unsigned char c = QRCode[i];
 108         if (isCharUnreservedInRfc3986(c))
 109         {
 110
 111             VerifyOrExit((j + 1) < maxSize, err = CHIP_ERROR_BUFFER_TOO_SMALL);
 112
 113             url[j++] = c;
 114         }
 115         else
 116         {
 117
 118             VerifyOrExit((j + 3) < maxSize, err = CHIP_ERROR_BUFFER_TOO_SMALL);
 119
 120             url[j++] = '%';
 121             url[j++] = upperHexDigits[(c & 0xf0) >> 4];
 122             url[j++] = upperHexDigits[(c & 0x0f)];
 123         }
 124     }
 125
 126     url[j] = '\0';
 127
 128 exit:
 129     return err;
 130 }