Merge pull request #164 from bhaskar-apple/BS-QRCodeParser

Base45 to a Set up payload

src/setup_payload/Base45.cpp

@@ -29,11 +29,14 @@
 
 #include "Base45.h"
 
+#include <iostream>
+
 using namespace std;
 
 namespace chip {
 
 static const int kBase45ChunkLen = 3;
+static const int kBytesChunkLen  = 2;
 
 string base45Encode(const uint8_t * buf, size_t buf_len)
 {
@@ -46,7 +49,8 @@ string base45Encode(const uint8_t * buf, size_t buf_len)
 
     // eat little-endian uint16_ts from the byte array
     // encode as 3 base45 characters
-    while (buf_len >= 2)
+
+    while (buf_len >= kBytesChunkLen)
     {
         int next = buf[0] + buf[1] * 256;
 
@@ -55,8 +59,8 @@ string base45Encode(const uint8_t * buf, size_t buf_len)
             result += codes[next % radix];
             next /= radix;
         }
-        buf += 2;
-        buf_len -= 2;
+        buf += kBytesChunkLen;
+        buf_len -= kBytesChunkLen;
     }
     // handle leftover byte, if any
     if (buf_len != 0)
@@ -156,6 +160,7 @@ CHIP_ERROR base45Decode(string base45, vector<uint8_t> & result)
     //  base45 characters
     if (base45.length() % kBase45ChunkLen == 1)
     {
+        fprintf(stderr, "\nFailed decoding base45. Input was too short. %lu", base45.length());
         return CHIP_ERROR_INVALID_MESSAGE_LENGTH;
     }
     result.clear();

src/setup_payload/QRCodeSetupPayloadGenerator.cpp

@@ -37,6 +37,7 @@ static void populateBits(uint8_t * bits, int & offset, uint64_t input, size_t nu
     // do nothing in the case where we've overflowed. should never happen
     if (offset + numberOfBits > kTotalPayloadDataSizeInBits || input >= 1u << numberOfBits)
     {
+        fprintf(stderr, "Overflow while trying to generate a QR Code. Bailing.");
         return;
     }
 
@@ -86,7 +87,11 @@ string QRCodeSetupPayloadGenerator::payloadBinaryRepresentation()
         }
         return binary;
     }
-    return string();
+    else
+    {
+        fprintf(stderr, "\nFailed encoding invalid payload\n");
+        return string();
+    }
 }
 
 string QRCodeSetupPayloadGenerator::payloadBase45Representation()
@@ -99,5 +104,9 @@ string QRCodeSetupPayloadGenerator::payloadBase45Representation()
 
         return base45Encode(bits, sizeof(bits) / sizeof(bits[0]));
     }
-    return string();
+    else
+    {
+        fprintf(stderr, "\nFailed encoding invalid payload\n");
+        return string();
+    }
 }

src/setup_payload/QRCodeSetupPayloadGenerator.h

@@ -29,7 +29,6 @@
 
 #include "SetupPayload.h"
 
-#include <bitset>
 #include <string>
 using namespace std;
 

src/setup_payload/QRCodeSetupPayloadParser.cpp

@@ -0,0 +1,123 @@
+/**
+ *
+ *    <COPYRIGHT>
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+/**
+ *    @file
+ *      This file describes a QRCode Setup Payload parser based on the
+ *      CHIP specification.
+ */
+
+#include "QRCodeSetupPayloadParser.h"
+#include "Base45.h"
+
+#include <core/CHIPError.h>
+#include <iostream>
+#include <vector>
+
+using namespace chip;
+using namespace std;
+
+// Populate numberOfBits into dest from buf starting at startIndex
+static CHIP_ERROR readBits(vector<uint8_t> buf, int & index, uint64_t & dest, size_t numberOfBitsToRead)
+{
+    dest = 0;
+    if (index + numberOfBitsToRead > buf.size() * 8 || numberOfBitsToRead > sizeof(uint64_t) * 8)
+    {
+        fprintf(stderr, "Error parsing QR code. startIndex %d numberOfBitsToLoad %zu buf_len %zu ", index, numberOfBitsToRead,
+                buf.size());
+        return CHIP_ERROR_INVALID_ARGUMENT;
+    }
+
+    int currentIndex = index;
+    for (size_t bitsRead = 0; bitsRead < numberOfBitsToRead; bitsRead++)
+    {
+        if (buf[currentIndex / 8] & (1 << (currentIndex % 8)))
+        {
+            dest |= (1 << bitsRead);
+        }
+        currentIndex++;
+    }
+    index += numberOfBitsToRead;
+    return CHIP_NO_ERROR;
+}
+
+CHIP_ERROR QRCodeSetupPayloadParser::populatePayload(SetupPayload & outPayload)
+{
+    vector<uint8_t> buf = vector<uint8_t>();
+
+    CHIP_ERROR result = base45Decode(mBase45Representation, buf);
+
+    if (CHIP_NO_ERROR != result)
+    {
+        fprintf(stderr, "Decoding of base45 string failed");
+        return result;
+    }
+
+    int indexToReadFrom = 0;
+    uint64_t dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kVersionFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.version = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kVendorIDFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.vendorID = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kProductIDFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.productID = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kCustomFlowRequiredFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.requiresCustomFlow = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kRendezvousInfoFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.rendezvousInformation = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kPayloadDiscriminatorFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.discriminator = dest;
+
+    result = readBits(buf, indexToReadFrom, dest, kSetupPINCodeFieldLengthInBits);
+    if (result != CHIP_NO_ERROR)
+    {
+        return result;
+    }
+    outPayload.setUpPINCode = dest;
+
+    return result;
+}

src/setup_payload/QRCodeSetupPayloadParser.h

@@ -0,0 +1,46 @@
+/**
+ *
+ *    <COPYRIGHT>
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+/**
+ *    @file
+ *      This file describes a QRCode Setup Payload parser based on the
+ *      CHIP specification.
+ */
+
+#include "SetupPayload.h"
+
+#include <core/CHIPError.h>
+#include <string>
+using namespace std;
+
+namespace chip {
+
+/**
+ * @class QRCodeSetupPayloadParser
+ * A class that can be used to convert a base45 encoded payload to a SetupPayload object
+ * */
+class QRCodeSetupPayloadParser
+{
+private:
+    string mBase45Representation;
+
+public:
+    QRCodeSetupPayloadParser(string base45Representation) : mBase45Representation(base45Representation){};
+    CHIP_ERROR populatePayload(SetupPayload & outPayload);
+};
+
+}; // namespace chip

src/setup_payload/SetupPayload.cpp

@@ -47,14 +47,20 @@ bool SetupPayload::isValid()
     {
         return false;
     }
-    // make sure the rendezvousInformation only uses allowed values
-    // i.e it must be > 0 and set to 1 or a power of 2.
-    uint16_t rezInfo = rendezvousInformation;
-    if (rezInfo == 0 || (rezInfo != 1 && (rezInfo & (rezInfo - 1)) != 0))
+
+    if (version == 0 && rendezvousInformation == 0 && discriminator == 0 && setUpPINCode == 0)
     {
         return false;
     }
+
     return true;
 }
 
+bool SetupPayload::operator==(const SetupPayload & input)
+{
+    return this->version == input.version && this->vendorID == input.vendorID && this->productID == input.productID &&
+        this->requiresCustomFlow == input.requiresCustomFlow && this->rendezvousInformation == input.rendezvousInformation &&
+        this->discriminator == input.discriminator && this->setUpPINCode == input.setUpPINCode;
+}
+
 } // namespace chip

src/setup_payload/SetupPayload.h

@@ -25,6 +25,9 @@
 #define _SETUP_PAYLOAD_H_
 
 #include <stdint.h>
+#include <string>
+
+using namespace std;
 
 namespace chip {
 // TODO this shuould point to the spec
@@ -55,7 +58,11 @@ class SetupPayload
     uint32_t setUpPINCode;
 
     // Test that the Setup Payload is within expected value ranges
+    SetupPayload() :
+        version(0), vendorID(0), productID(0), requiresCustomFlow(0), rendezvousInformation(0), discriminator(0), setUpPINCode(0){};
+
     bool isValid();
+    bool operator==(const SetupPayload & input);
 };
 
 }; // namespace chip

src/setup_payload/tests/Makefile.am

@@ -70,7 +70,7 @@ TESTS_ENVIRONMENT                              = \
 # Source, compiler, and linker options for test programs.
 
 TestQrCode_LDADD                               = $(COMMON_LDADD)
-TestQrCode_SOURCES                             = tests.cpp
+TestQrCode_SOURCES                             = tests_qrcode.cpp
 
 if CHIP_BUILD_COVERAGE
 CLEANFILES                                     = $(wildcard *.gcda *.gcno)