Beispiel #1
0
        private CBORObject ObjectFromByteArray(byte[] data, int lengthHint)
        {
            CBORObject cbor = CBORObject.FromRaw(data);

            if (this.stringRefs != null)
            {
                this.stringRefs.AddStringIfNeeded(cbor, lengthHint);
            }
            return(cbor);
        }
Beispiel #2
0
        internal CBORObject ParseJSONArray(int depth)
        {
            // Assumes that the last character read was '['
            if (depth > 1000)
            {
                this.RaiseError("Too deeply nested");
            }
            var myArrayList = new List <CBORObject>();
            var seenComma   = false;
            var nextchar    = new int[1];

            while (true)
            {
                int c = this.SkipWhitespaceJSON();
                if (c == ']')
                {
                    if (seenComma)
                    {
                        // Situation like '[0,1,]'
                        this.RaiseError("Trailing comma");
                    }
                    return(CBORObject.FromRaw(myArrayList));
                }
                if (c == ',')
                {
                    // Situation like '[,0,1,2]' or '[0,,1]'
                    this.RaiseError("Empty array element");
                }
                myArrayList.Add(
                    this.NextJSONValue(
                        c,
                        nextchar,
                        depth));
                c = nextchar[0];
                switch (c)
                {
                case ',':
                    seenComma = true;
                    break;

                case ']':
                    return(CBORObject.FromRaw(myArrayList));

                default: this.RaiseError("Expected a ',' or ']'");
                    break;
                }
            }
        }
Beispiel #3
0
        private CBORObject ParseJSONObject(int depth)
        {
            // Assumes that the last character read was '{'
            if (depth > 1000)
            {
                this.RaiseError("Too deeply nested");
            }
            int        c;
            CBORObject key = null;
            CBORObject obj;
            var        nextchar  = new int[1];
            var        seenComma = false;
            var        myHashMap = new Dictionary <CBORObject, CBORObject>();

            while (true)
            {
                c = this.SkipWhitespaceJSON();
                switch (c)
                {
                case -1:
                    this.RaiseError("A JSON object must end with '}'");
                    break;

                case '}':
                    if (seenComma)
                    {
                        // Situation like '{"0"=>1,}'
                        this.RaiseError("Trailing comma");
                        return(null);
                    }
                    return(CBORObject.FromRaw(myHashMap));

                default: {
                    // Read the next string
                    if (c < 0)
                    {
                        this.RaiseError("Unexpected end of data");
                        return(null);
                    }
                    if (c != '"')
                    {
                        this.RaiseError("Expected a string as a key");
                        return(null);
                    }
                    // Parse a string that represents the object's key
                    // The tokenizer already checked the string for invalid
                    // surrogate pairs, so just call the CBORObject
                    // constructor directly
                    obj = CBORObject.FromRaw(this.NextJSONString());
                    key = obj;
                    if (!this.options.AllowDuplicateKeys &&
                        myHashMap.ContainsKey(obj))
                    {
                        this.RaiseError("Key already exists: " + key);
                        return(null);
                    }
                    break;
                }
                }
                if (this.SkipWhitespaceJSON() != ':')
                {
                    this.RaiseError("Expected a ':' after a key");
                }
                // NOTE: Will overwrite existing value
                myHashMap[key] = this.NextJSONValue(
                    this.SkipWhitespaceJSON(),
                    nextchar,
                    depth);
                switch (nextchar[0])
                {
                case ',':
                    seenComma = true;
                    break;

                case '}':
                    return(CBORObject.FromRaw(myHashMap));

                default: this.RaiseError("Expected a ',' or '}'");
                    break;
                }
            }
        }
Beispiel #4
0
        private CBORObject NextJSONValue(
            int firstChar,
            int[] nextChar,
            int depth)
        {
            int        c   = firstChar;
            CBORObject obj = null;

            if (c < 0)
            {
                this.RaiseError("Unexpected end of data");
            }
            switch (c)
            {
            case '"': {
                // Parse a string
                // The tokenizer already checked the string for invalid
                // surrogate pairs, so just call the CBORObject
                // constructor directly
                obj         = CBORObject.FromRaw(this.NextJSONString());
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case '{': {
                // Parse an object
                obj         = this.ParseJSONObject(depth + 1);
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case '[': {
                // Parse an array
                obj         = this.ParseJSONArray(depth + 1);
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case 't': {
                // Parse true
                if (this.endPos - this.index <= 2 ||
                    (((int)this.bytes[this.index]) & 0xFF) != 'r' ||
                    (((int)this.bytes[this.index + 1]) & 0xFF) != 'u' ||
                    (((int)this.bytes[this.index + 2]) & 0xFF) != 'e')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                this.index += 3;
                nextChar[0] = this.SkipWhitespaceJSON();
                return(CBORObject.True);
            }

            case 'f': {
                // Parse false
                if (this.endPos - this.index <= 3 ||
                    (((int)this.bytes[this.index]) & 0xFF) != 'a' ||
                    (((int)this.bytes[this.index + 1]) & 0xFF) != 'l' ||
                    (((int)this.bytes[this.index + 2]) & 0xFF) != 's' ||
                    (((int)this.bytes[this.index + 3]) & 0xFF) != 'e')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                this.index += 4;
                nextChar[0] = this.SkipWhitespaceJSON();
                return(CBORObject.False);
            }

            case 'n': {
                // Parse null
                if (this.endPos - this.index <= 2 ||
                    (((int)this.bytes[this.index]) & 0xFF) != 'u' ||
                    (((int)this.bytes[this.index + 1]) & 0xFF) != 'l' ||
                    (((int)this.bytes[this.index + 2]) & 0xFF) != 'l')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                this.index += 3;
                nextChar[0] = this.SkipWhitespaceJSON();
                return(CBORObject.Null);
            }

            case '-': {
                // Parse a negative number
                return(this.NextJSONNegativeNumber(nextChar));
            }

            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9': {
                // Parse a nonnegative number
                return(this.NextJSONNonnegativeNumber(c, nextChar));
            }

            default:
                this.RaiseError("Value can't be parsed.");
                break;
            }
            return(null);
        }
Beispiel #5
0
        public CBORObject ReadForFirstByte(int firstbyte)
        {
            if (this.depth > 500)
            {
                throw new CBORException("Too deeply nested");
            }
            if (firstbyte < 0)
            {
                throw new CBORException("Premature end of data");
            }
            if (firstbyte == 0xff)
            {
                throw new CBORException("Unexpected break code encountered");
            }
            int        type       = (firstbyte >> 5) & 0x07;
            int        additional = firstbyte & 0x1f;
            long       uadditional;
            CBORObject fixedObject;

            if (this.options.Ctap2Canonical)
            {
                if (additional >= 0x1c)
                {
                    // NOTE: Includes stop byte and indefinite length data items
                    throw new CBORException("Invalid canonical CBOR encountered");
                }
                // Check if this represents a fixed object (NOTE: All fixed objects
                // comply with CTAP2 canonical CBOR).
                fixedObject = CBORObject.GetFixedObject(firstbyte);
                if (fixedObject != null)
                {
                    return(fixedObject);
                }
                if (type == 6)
                {
                    throw new CBORException("Tags not allowed in canonical CBOR");
                }
                uadditional = ReadDataLength(
                    this.stream,
                    firstbyte,
                    type,
                    type == 7);
                if (type == 0)
                {
                    return((uadditional >> 63) != 0 ?
                           CBORObject.FromObject(ToUnsignedEInteger(uadditional)) :
                           CBORObject.FromObject(uadditional));
                }
                else if (type == 1)
                {
                    return((uadditional >> 63) != 0 ? CBORObject.FromObject(
                               ToUnsignedEInteger(uadditional).Add(1).Negate()) :
                           CBORObject.FromObject((-uadditional) - 1L));
                }
                else if (type == 7)
                {
                    if (additional < 24)
                    {
                        return(CBORObject.FromSimpleValue(additional));
                    }
                    else if (additional == 24 && uadditional < 32)
                    {
                        throw new CBORException("Invalid simple value encoding");
                    }
                    else if (additional == 24)
                    {
                        return(CBORObject.FromSimpleValue((int)uadditional));
                    }
                    else if (additional == 25)
                    {
                        return(CBORObject.FromFloatingPointBits(uadditional, 2));
                    }
                    else if (additional == 26)
                    {
                        return(CBORObject.FromFloatingPointBits(uadditional, 4));
                    }
                    else if (additional == 27)
                    {
                        return(CBORObject.FromFloatingPointBits(uadditional, 8));
                    }
                }
                else if (type >= 2 && type <= 5)
                {
                    return(this.ReadStringArrayMap(type, uadditional));
                }
                throw new CBORException("Unexpected data encountered");
            }
            int expectedLength = CBORObject.GetExpectedLength(firstbyte);

            // Data checks
            if (expectedLength == -1)
            {
                // if the head byte is invalid
                throw new CBORException("Unexpected data encountered");
            }
            // Check if this represents a fixed object
            fixedObject = CBORObject.GetFixedObject(firstbyte);
            if (fixedObject != null)
            {
                return(fixedObject);
            }
            // Read fixed-length data
            byte[] data = null;
            if (expectedLength != 0)
            {
                data = new byte[expectedLength];
                // include the first byte because GetFixedLengthObject
                // will assume it exists for some head bytes
                data[0] = unchecked ((byte)firstbyte);
                if (expectedLength > 1 &&
                    this.stream.Read(data, 1, expectedLength - 1) != expectedLength
                    - 1)
                {
                    throw new CBORException("Premature end of data");
                }
                CBORObject cbor = CBORObject.GetFixedLengthObject(firstbyte, data);
                if (this.stringRefs != null && (type == 2 || type == 3))
                {
                    this.stringRefs.AddStringIfNeeded(cbor, expectedLength - 1);
                }
                return(cbor);
            }
            if (additional == 31)
            {
                // Indefinite-length for major types 2 to 5 (other major
                // types were already handled in the call to
                // GetFixedLengthObject).
                switch (type)
                {
                case 2: {
                    // Streaming byte string
                    using (var ms = new MemoryStream()) {
                        // Requires same type as this one
                        while (true)
                        {
                            int nextByte = this.stream.ReadByte();
                            if (nextByte == 0xff)
                            {
                                // break if the "break" code was read
                                break;
                            }
                            long len = ReadDataLength(this.stream, nextByte, 2);
                            if ((len >> 63) != 0 || len > Int32.MaxValue)
                            {
                                throw new CBORException("Length" + ToUnsignedEInteger(len)
                                                        +
                                                        " is bigger than supported ");
                            }
                            if (nextByte != 0x40)
                            {
                                // NOTE: 0x40 means the empty byte string
                                ReadByteData(this.stream, len, ms);
                            }
                        }
                        if (ms.Position > Int32.MaxValue)
                        {
                            throw new
                                  CBORException("Length of bytes to be streamed is bigger" +
                                                "\u0020than supported ");
                        }
                        data = ms.ToArray();
                        return(CBORObject.FromRaw(data));
                    }
                }

                case 3: {
                    // Streaming text string
                    var builder = new StringBuilder();
                    while (true)
                    {
                        int nextByte = this.stream.ReadByte();
                        if (nextByte == 0xff)
                        {
                            // break if the "break" code was read
                            break;
                        }
                        long len = ReadDataLength(this.stream, nextByte, 3);
                        if ((len >> 63) != 0 || len > Int32.MaxValue)
                        {
                            throw new CBORException("Length" + ToUnsignedEInteger(len) +
                                                    " is bigger than supported");
                        }
                        if (nextByte != 0x60)
                        {
                            // NOTE: 0x60 means the empty string
                            if (PropertyMap.ExceedsKnownLength(this.stream, len))
                            {
                                throw new CBORException("Premature end of data");
                            }
                            switch (
                                DataUtilities.ReadUtf8(
                                    this.stream,
                                    (int)len,
                                    builder,
                                    false))
                            {
                            case -1:
                                throw new CBORException("Invalid UTF-8");

                            case -2:
                                throw new CBORException("Premature end of data");
                            }
                        }
                    }
                    return(CBORObject.FromRaw(builder.ToString()));
                }

                case 4: {
                    CBORObject cbor    = CBORObject.NewArray();
                    var        vtindex = 0;
                    // Indefinite-length array
                    while (true)
                    {
                        int headByte = this.stream.ReadByte();
                        if (headByte < 0)
                        {
                            throw new CBORException("Premature end of data");
                        }
                        if (headByte == 0xff)
                        {
                            // Break code was read
                            break;
                        }
                        ++this.depth;
                        CBORObject o = this.ReadForFirstByte(
                            headByte);
                        --this.depth;
                        cbor.Add(o);
                        ++vtindex;
                    }
                    return(cbor);
                }

                case 5: {
                    CBORObject cbor = CBORObject.NewMap();
                    // Indefinite-length map
                    while (true)
                    {
                        int headByte = this.stream.ReadByte();
                        if (headByte < 0)
                        {
                            throw new CBORException("Premature end of data");
                        }
                        if (headByte == 0xff)
                        {
                            // Break code was read
                            break;
                        }
                        ++this.depth;
                        CBORObject key   = this.ReadForFirstByte(headByte);
                        CBORObject value = this.ReadInternal();
                        --this.depth;
                        if (!this.options.AllowDuplicateKeys)
                        {
                            if (cbor.ContainsKey(key))
                            {
                                throw new CBORException("Duplicate key already exists");
                            }
                        }
                        cbor[key] = value;
                    }
                    return(cbor);
                }

                default: throw new CBORException("Unexpected data encountered");
                }
            }
            EInteger bigintAdditional = EInteger.Zero;

            uadditional = ReadDataLength(this.stream, firstbyte, type);
            // The following doesn't check for major types 0 and 1,
            // since all of them are fixed-length types and are
            // handled in the call to GetFixedLengthObject.
            if (type >= 2 && type <= 5)
            {
                return(this.ReadStringArrayMap(type, uadditional));
            }
            if (type == 6) // Tagged item
            {
                var haveFirstByte = false;
                var newFirstByte  = -1;
                if (this.options.ResolveReferences && (uadditional >> 32) == 0)
                {
                    // NOTE: HandleItemTag treats only certain tags up to 256 specially
                    this.HandleItemTag(uadditional);
                }
                ++this.depth;
                CBORObject o = haveFirstByte ? this.ReadForFirstByte(
                    newFirstByte) : this.ReadInternal();
                --this.depth;
                if ((uadditional >> 63) != 0)
                {
                    return(CBORObject.FromObjectAndTag(o,
                                                       ToUnsignedEInteger(uadditional)));
                }
                if (uadditional < 65536)
                {
                    if (this.options.ResolveReferences)
                    {
                        int uaddl = uadditional >= 257 ? 257 : (uadditional < 0 ? 0 :
                                                                (int)uadditional);
                        switch (uaddl)
                        {
                        case 256:
                            // string tag
                            this.stringRefs.Pop();
                            break;

                        case 25:
                            // stringref tag
                            if (o.IsTagged || o.Type != CBORType.Integer)
                            {
                                throw new CBORException("stringref must be an unsigned" +
                                                        "\u0020integer");
                            }
                            return(this.stringRefs.GetString(o.AsEIntegerValue()));
                        }
                    }
                    return(CBORObject.FromObjectAndTag(
                               o,
                               (int)uadditional));
                }
                return(CBORObject.FromObjectAndTag(
                           o,
                           (EInteger)uadditional));
            }
            throw new CBORException("Unexpected data encountered");
        }
Beispiel #6
0
        private CBORObject ReadStringArrayMap(int type, long uadditional)
        {
            bool canonical = this.options.Ctap2Canonical;

            if (type == 2) // Byte string
            {
                if ((uadditional >> 31) != 0)
                {
                    throw new CBORException("Length of " +
                                            ToUnsignedEInteger(uadditional).ToString() + " is bigger" +
                                            "\u0020than supported");
                }
                int hint = (uadditional > Int32.MaxValue ||
                            (uadditional >> 63) != 0) ? Int32.MaxValue : (int)uadditional;
                byte[] data = ReadByteData(this.stream, uadditional, null);
                return(this.ObjectFromByteArray(data, hint));
            }
            if (type == 3) // Text string
            {
                if ((uadditional >> 31) != 0)
                {
                    throw new CBORException("Length of " +
                                            ToUnsignedEInteger(uadditional).ToString() + " is bigger" +
                                            "\u0020than supported");
                }
                if (PropertyMap.ExceedsKnownLength(this.stream, uadditional))
                {
                    throw new CBORException("Premature end of data");
                }
                var builder = new StringBuilder();
                switch (
                    DataUtilities.ReadUtf8(
                        this.stream,
                        (int)uadditional,
                        builder,
                        false))
                {
                case -1:
                    throw new CBORException("Invalid UTF-8");

                case -2:
                    throw new CBORException("Premature end of data");
                }
                CBORObject cbor = CBORObject.FromRaw(builder.ToString());
                if (this.stringRefs != null)
                {
                    int hint = (uadditional > Int32.MaxValue || (uadditional >> 63) !=
                                0) ? Int32.MaxValue : (int)uadditional;
                    this.stringRefs.AddStringIfNeeded(cbor, hint);
                }
                return(cbor);
            }
            if (type == 4) // Array
            {
                if (this.options.Ctap2Canonical && this.depth >= 4)
                {
                    throw new CBORException("Depth too high in canonical CBOR");
                }
                CBORObject cbor = CBORObject.NewArray();
                if ((uadditional >> 31) != 0)
                {
                    throw new CBORException("Length of " +
                                            ToUnsignedEInteger(uadditional).ToString() + " is bigger than" +
                                            "\u0020supported");
                }
                if (PropertyMap.ExceedsKnownLength(this.stream, uadditional))
                {
                    throw new CBORException("Remaining data too small for array" +
                                            "\u0020length");
                }
                ++this.depth;
                for (long i = 0; i < uadditional; ++i)
                {
                    cbor.Add(
                        this.ReadInternal());
                }
                --this.depth;
                return(cbor);
            }
            if (type == 5) // Map, type 5
            {
                if (this.options.Ctap2Canonical && this.depth >= 4)
                {
                    throw new CBORException("Depth too high in canonical CBOR");
                }
                CBORObject cbor = CBORObject.NewMap();
                if ((uadditional >> 31) != 0)
                {
                    throw new CBORException("Length of " +
                                            ToUnsignedEInteger(uadditional).ToString() + " is bigger than" +
                                            "\u0020supported");
                }
                if (PropertyMap.ExceedsKnownLength(this.stream, uadditional))
                {
                    throw new CBORException("Remaining data too small for map" +
                                            "\u0020length");
                }
                CBORObject             lastKey  = null;
                IComparer <CBORObject> comparer = CBORCanonical.Comparer;
                for (long i = 0; i < uadditional; ++i)
                {
                    ++this.depth;
                    CBORObject key   = this.ReadInternal();
                    CBORObject value = this.ReadInternal();
                    --this.depth;
                    if (this.options.Ctap2Canonical && lastKey != null)
                    {
                        int cmp = comparer.Compare(lastKey, key);
                        if (cmp > 0)
                        {
                            throw new CBORException("Map key not in canonical order");
                        }
                        else if (cmp == 0)
                        {
                            throw new CBORException("Duplicate map key");
                        }
                    }
                    if (!this.options.AllowDuplicateKeys)
                    {
                        if (cbor.ContainsKey(key))
                        {
                            throw new CBORException("Duplicate key already exists");
                        }
                    }
                    lastKey   = key;
                    cbor[key] = value;
                }
                return(cbor);
            }
            return(null);
        }
Beispiel #7
0
        private CBORObject NextJSONValue(
            int firstChar,
            int[] nextChar,
            int depth)
        {
            string     str;
            int        c   = firstChar;
            CBORObject obj = null;

            if (c < 0)
            {
                this.RaiseError("Unexpected end of data");
            }
            switch (c)
            {
            case '"': {
                // Parse a string
                // The tokenizer already checked the string for invalid
                // surrogate pairs, so just call the CBORObject
                // constructor directly
                obj         = CBORObject.FromRaw(this.NextJSONString());
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case '{': {
                // Parse an object
                obj         = this.ParseJSONObject(depth + 1);
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case '[': {
                // Parse an array
                obj         = this.ParseJSONArray(depth + 1);
                nextChar[0] = this.SkipWhitespaceJSON();
                return(obj);
            }

            case 't': {
                // Parse true
                if ((c = this.ReadChar()) != 'r' || (c = this.ReadChar()) != 'u' ||
                    (c = this.ReadChar()) != 'e')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                c = this.ReadChar();
                if (c == 0x20 || c == 0x0a || c == 0x0d || c == 0x09)
                {
                    nextChar[0] = this.SkipWhitespaceJSON();
                }
                else if (this.jsonSequenceMode && depth == 0)
                {
                    nextChar[0] = c;
                    this.RaiseError("JSON whitespace expected after top-level " +
                                    "number in JSON sequence");
                }
                else
                {
                    nextChar[0] = c;
                }
                return(CBORObject.True);
            }

            case 'f': {
                // Parse false
                if ((c = this.ReadChar()) != 'a' || (c = this.ReadChar()) != 'l' ||
                    (c = this.ReadChar()) != 's' || (c = this.ReadChar()) != 'e')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                c = this.ReadChar();
                if (c == 0x20 || c == 0x0a || c == 0x0d || c == 0x09)
                {
                    nextChar[0] = this.SkipWhitespaceJSON();
                }
                else if (this.jsonSequenceMode && depth == 0)
                {
                    nextChar[0] = c;
                    this.RaiseError("JSON whitespace expected after top-level " +
                                    "number in JSON sequence");
                }
                else
                {
                    nextChar[0] = c;
                }
                return(CBORObject.False);
            }

            case 'n': {
                // Parse null
                if ((c = this.ReadChar()) != 'u' || (c = this.ReadChar()) != 'l' ||
                    (c = this.ReadChar()) != 'l')
                {
                    this.RaiseError("Value can't be parsed.");
                }
                c = this.ReadChar();
                if (c == 0x20 || c == 0x0a || c == 0x0d || c == 0x09)
                {
                    nextChar[0] = this.SkipWhitespaceJSON();
                }
                else if (this.jsonSequenceMode && depth == 0)
                {
                    nextChar[0] = c;
                    this.RaiseError("JSON whitespace expected after top-level " +
                                    "number in JSON sequence");
                }
                else
                {
                    nextChar[0] = c;
                }
                return(CBORObject.Null);
            }

            case '-': {
                // Parse a negative number
                return(this.NextJSONNegativeNumber(nextChar, depth));
            }

            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9': {
                // Parse a nonnegative number
                int cval    = c - '0';
                int cstart  = c;
                var needObj = true;
                c = this.ReadChar();
                if (!(c == '-' || c == '+' || c == '.' || (c >= '0' && c <= '9') ||
                      c == 'e' || c == 'E'))
                {
                    // Optimize for common case where JSON number
                    // is a single digit without sign or exponent
                    obj     = CBORDataUtilities.ParseSmallNumber(cval, this.options);
                    needObj = false;
                }
                else if (c >= '0' && c <= '9')
                {
                    int csecond = c;
                    if (cstart == '0')
                    {
                        // Leading zero followed by any digit is not allowed
                        this.RaiseError("JSON number can't be parsed.");
                    }
                    cval = (cval * 10) + (int)(c - '0');
                    c    = this.ReadChar();
                    if (c >= '0' && c <= '9')
                    {
                        var digits = 2;
                        var ctmp   = new int[10];
                        ctmp[0] = cstart;
                        ctmp[1] = csecond;
                        while (digits < 9 && (c >= '0' && c <= '9'))
                        {
                            cval           = (cval * 10) + (int)(c - '0');
                            ctmp[digits++] = c;
                            c = this.ReadChar();
                        }
                        if (c == 'e' || c == 'E' || c == '.' || (c >= '0' && c <= '9'))
                        {
                            // Not an all-digit number, or too long
                            this.sb = this.sb ?? new StringBuilder();
                            this.sb.Remove(0, this.sb.Length);
                            for (var vi = 0; vi < digits; ++vi)
                            {
                                this.sb.Append((char)ctmp[vi]);
                            }
                        }
                        else
                        {
                            obj     = CBORDataUtilities.ParseSmallNumber(cval, this.options);
                            needObj = false;
                        }
                    }
                    else if (!(c == '-' || c == '+' || c == '.' || c == 'e' || c
                               == 'E'))
                    {
                        // Optimize for common case where JSON number
                        // is two digits without sign, decimal point, or exponent
                        obj     = CBORDataUtilities.ParseSmallNumber(cval, this.options);
                        needObj = false;
                    }
                    else
                    {
                        this.sb = this.sb ?? new StringBuilder();
                        this.sb.Remove(0, this.sb.Length);
                        this.sb.Append((char)cstart);
                        this.sb.Append((char)csecond);
                    }
                }
                else
                {
                    this.sb = this.sb ?? new StringBuilder();
                    this.sb.Remove(0, this.sb.Length);
                    this.sb.Append((char)cstart);
                }
                if (needObj)
                {
                    var charbuf    = new char[32];
                    var charbufptr = 0;
                    while (
                        c == '-' || c == '+' || c == '.' || (c >= '0' && c <= '9') ||
                        c == 'e' || c == 'E')
                    {
                        charbuf[charbufptr++] = (char)c;
                        if (charbufptr >= 32)
                        {
                            this.sb.Append(charbuf, 0, 32);
                            charbufptr = 0;
                        }
                        c = this.ReadChar();
                    }
                    if (charbufptr > 0)
                    {
                        this.sb.Append(charbuf, 0, charbufptr);
                    }
                    // check if character can validly appear after a JSON number
                    if (c != ',' && c != ']' && c != '}' && c != -1 &&
                        c != 0x20 && c != 0x0a && c != 0x0d && c != 0x09)
                    {
                        this.RaiseError("Invalid character after JSON number");
                    }
                    str = this.sb.ToString();
                    obj = CBORDataUtilities.ParseJSONNumber(str, this.options);
                    if (obj == null)
                    {
                        string errstr = (str.Length <= 100) ? str : (str.Substring(0,
                                                                                   100) + "...");
                        this.RaiseError("JSON number can't be parsed. " + errstr);
                    }
                }
                if (c == 0x20 || c == 0x0a || c == 0x0d || c == 0x09)
                {
                    nextChar[0] = this.SkipWhitespaceJSON();
                }
                else if (this.jsonSequenceMode && depth == 0)
                {
                    nextChar[0] = c;
                    this.RaiseError("JSON whitespace expected after top-level " +
                                    "number in JSON sequence");
                }
                else
                {
                    nextChar[0] = c;
                }
                return(obj);
            }

            default: this.RaiseError("Value can't be parsed.");
                break;
            }
            return(null);
        }