// Vulnerability label: clean
pragma solidity ^0.4.23;

// File: @ensdomains/dnssec-oracle/contracts/BytesUtils.sol

library BytesUtils {
    /*
    * @dev Returns the keccak-256 hash of a byte range.
    * @param self The byte string to hash.
    * @param offset The position to start hashing at.
    * @param len The number of bytes to hash.
    * @return The hash of the byte range.
    */
    function keccak(bytes memory self, uint offset, uint len) internal pure returns (bytes32 ret) {
        require(offset + len <= self.length);
        assembly {
            ret := sha3(add(add(self, 32), offset), len)
        }
    }


    /*
    * @dev Returns a positive number if `other` comes lexicographically after
    *      `self`, a negative number if it comes before, or zero if the
    *      contents of the two bytes are equal.
    * @param self The first bytes to compare.
    * @param other The second bytes to compare.
    * @return The result of the comparison.
    */
    function compare(bytes memory self, bytes memory other) internal pure returns (int) {
        return compare(self, 0, self.length, other, 0, other.length);
    }

    /*
    * @dev Returns a positive number if `other` comes lexicographically after
    *      `self`, a negative number if it comes before, or zero if the
    *      contents of the two bytes are equal. Comparison is done per-rune,
    *      on unicode codepoints.
    * @param self The first bytes to compare.
    * @param offset The offset of self.
    * @param len    The length of self.
    * @param other The second bytes to compare.
    * @param otheroffset The offset of the other string.
    * @param otherlen    The length of the other string.
    * @return The result of the comparison.
    */
    function compare(bytes memory self, uint offset, uint len, bytes memory other, uint otheroffset, uint otherlen) internal pure returns (int) {
        uint shortest = len;
        if (otherlen < len)
        shortest = otherlen;

        uint selfptr;
        uint otherptr;

        assembly {
            selfptr := add(self, add(offset, 32))
            otherptr := add(other, add(otheroffset, 32))
        }
        for (uint idx = 0; idx < shortest; idx += 32) {
            uint a;
            uint b;
            assembly {
                a := mload(selfptr)
                b := mload(otherptr)
            }
            if (a != b) {
                // Mask out irrelevant bytes and check again
                uint mask;
                if (shortest > 32) {
                    mask = uint256(- 1); // aka 0xffffff....
                } else {
                    mask = ~(2 ** (8 * (32 - shortest + idx)) - 1);
                }
                uint diff = (a & mask) - (b & mask);
                if (diff != 0)
                return int(diff);
            }
            selfptr += 32;
            otherptr += 32;
        }

        return int(len) - int(otherlen);
    }

    /*
    * @dev Returns true if the two byte ranges are equal.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @param otherOffset The offset into the second byte range.
    * @param len The number of bytes to compare
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other, uint otherOffset, uint len) internal pure returns (bool) {
        return keccak(self, offset, len) == keccak(other, otherOffset, len);
    }

    /*
    * @dev Returns true if the two byte ranges are equal with offsets.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @param otherOffset The offset into the second byte range.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other, uint otherOffset) internal pure returns (bool) {
        return keccak(self, offset, self.length - offset) == keccak(other, otherOffset, other.length - otherOffset);
    }

    /*
    * @dev Compares a range of 'self' to all of 'other' and returns True iff
    *      they are equal.
    * @param self The first byte range to compare.
    * @param offset The offset into the first byte range.
    * @param other The second byte range to compare.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, uint offset, bytes memory other) internal pure returns (bool) {
        return self.length >= offset + other.length && equals(self, offset, other, 0, other.length);
    }

    /*
    * @dev Returns true if the two byte ranges are equal.
    * @param self The first byte range to compare.
    * @param other The second byte range to compare.
    * @return True if the byte ranges are equal, false otherwise.
    */
    function equals(bytes memory self, bytes memory other) internal pure returns(bool) {
        return self.length == other.length && equals(self, 0, other, 0, self.length);
    }

    /*
    * @dev Returns the 8-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 8 bits of the string, interpreted as an integer.
    */
    function readUint8(bytes memory self, uint idx) internal pure returns (uint8 ret) {
        require(idx + 1 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 1), idx)), 0xFF)
        }
    }

    /*
    * @dev Returns the 16-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 16 bits of the string, interpreted as an integer.
    */
    function readUint16(bytes memory self, uint idx) internal pure returns (uint16 ret) {
        require(idx + 2 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 2), idx)), 0xFFFF)
        }
    }

    /*
    * @dev Returns the 32-bit number at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bits of the string, interpreted as an integer.
    */
    function readUint32(bytes memory self, uint idx) internal pure returns (uint32 ret) {
        require(idx + 4 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 4), idx)), 0xFFFFFFFF)
        }
    }

    /*
    * @dev Returns the 32 byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bytes of the string.
    */
    function readBytes32(bytes memory self, uint idx) internal pure returns (bytes32 ret) {
        require(idx + 32 <= self.length);
        assembly {
            ret := mload(add(add(self, 32), idx))
        }
    }

    /*
    * @dev Returns the 32 byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes
    * @return The specified 32 bytes of the string.
    */
    function readBytes20(bytes memory self, uint idx) internal pure returns (bytes20 ret) {
        require(idx + 20 <= self.length);
        assembly {
            ret := and(mload(add(add(self, 32), idx)), 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF000000000000000000000000)
        }
    }

    /*
    * @dev Returns the n byte value at the specified index of self.
    * @param self The byte string.
    * @param idx The index into the bytes.
    * @param len The number of bytes.
    * @return The specified 32 bytes of the string.
    */
    function readBytesN(bytes memory self, uint idx, uint len) internal pure returns (bytes20 ret) {
        require(idx + len <= self.length);
        assembly {
            let mask := not(sub(exp(256, sub(32, len)), 1))
            ret := and(mload(add(add(self, 32), idx)),  mask)
        }
    }

    function memcpy(uint dest, uint src, uint len) private pure {
        // Copy word-length chunks while possible
        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /*
    * @dev Copies a substring into a new byte string.
    * @param self The byte string to copy from.
    * @param offset The offset to start copying at.
    * @param len The number of bytes to copy.
    */
    function substring(bytes memory self, uint offset, uint len) internal pure returns(bytes) {
        require(offset + len <= self.length);

        bytes memory ret = new bytes(len);
        uint dest;
        uint src;

        assembly {
            dest := add(ret, 32)
            src := add(add(self, 32), offset)
        }
        memcpy(dest, src, len);

        return ret;
    }

    // Maps characters from 0x30 to 0x7A to their base32 values.
    // 0xFF represents invalid characters in that range.
    bytes constant base32HexTable = hex'00010203040506070809FFFFFFFFFFFFFF0A0B0C0D0E0F101112131415161718191A1B1C1D1E1FFFFFFFFFFFFFFFFFFFFF0A0B0C0D0E0F101112131415161718191A1B1C1D1E1F';

    /**
     * @dev Decodes unpadded base32 data of up to one word in length.
     * @param self The data to decode.
     * @param off Offset into the string to start at.
     * @param len Number of characters to decode.
     * @return The decoded data, left aligned.
     */
    function base32HexDecodeWord(bytes memory self, uint off, uint len) internal pure returns(bytes32) {
        require(len <= 52);

        uint ret = 0;
        for(uint i = 0; i < len; i++) {
            byte char = self[off + i];
            require(char >= 0x30 && char <= 0x7A);
            uint8 decoded = uint8(base32HexTable[uint(char) - 0x30]);
            require(decoded <= 0x20);
            if(i == len - 1) {
                break;
            }
            ret = (ret << 5) | decoded;
        }

        uint bitlen = len * 5;
        if(len % 8 == 0) {
            // Multiple of 8 characters, no padding
            ret = (ret << 5) | decoded;
        } else if(len % 8 == 2) {
            // Two extra characters - 1 byte
            ret = (ret << 3) | (decoded >> 2);
            bitlen -= 2;
        } else if(len % 8 == 4) {
            // Four extra characters - 2 bytes
            ret = (ret << 1) | (decoded >> 4);
            bitlen -= 4;
        } else if(len % 8 == 5) {
            // Five extra characters - 3 bytes
            ret = (ret << 4) | (decoded >> 1);
            bitlen -= 1;
        } else if(len % 8 == 7) {
            // Seven extra characters - 4 bytes
            ret = (ret << 2) | (decoded >> 3);
            bitlen -= 3;
        } else {
            revert();
        }

        return bytes32(ret << (256 - bitlen));
    }
}

// File: @ensdomains/dnssec-oracle/contracts/DNSSEC.sol

interface DNSSEC {

    event AlgorithmUpdated(uint8 id, address addr);
    event DigestUpdated(uint8 id, address addr);
    event NSEC3DigestUpdated(uint8 id, address addr);
    event RRSetUpdated(bytes name, bytes rrset);

    function submitRRSets(bytes memory data, bytes memory proof) public returns (bytes);
    function submitRRSet(bytes memory input, bytes memory sig, bytes memory proof) public returns(bytes memory rrs);
    function deleteRRSet(uint16 deleteType, bytes deleteName, bytes memory nsec, bytes memory sig, bytes memory proof) public;
    function rrdata(uint16 dnstype, bytes memory name) public view returns (uint32, uint64, bytes20);

}

// File: @ensdomains/buffer/contracts/Buffer.sol

/**
* @dev A library for working with mutable byte buffers in Solidity.
*
* Byte buffers are mutable and expandable, and provide a variety of primitives
* for writing to them. At any time you can fetch a bytes object containing the
* current contents of the buffer. The bytes object should not be stored between
* operations, as it may change due to resizing of the buffer.
*/
library Buffer {
    /**
    * @dev Represents a mutable buffer. Buffers have a current value (buf) and
    *      a capacity. The capacity may be longer than the current value, in
    *      which case it can be extended without the need to allocate more memory.
    */
    struct buffer {
        bytes buf;
        uint capacity;
    }

    /**
    * @dev Initializes a buffer with an initial capacity.
    * @param buf The buffer to initialize.
    * @param capacity The number of bytes of space to allocate the buffer.
    * @return The buffer, for chaining.
    */
    function init(buffer memory buf, uint capacity) internal pure returns(buffer memory) {
        if (capacity % 32 != 0) {
            capacity += 32 - (capacity % 32);
        }
        // Allocate space for the buffer data
        buf.capacity = capacity;
        assembly {
            let ptr := mload(0x40)
            mstore(buf, ptr)
            mstore(ptr, 0)
            mstore(0x40, add(ptr, capacity))
        }
        return buf;
    }

    /**
    * @dev Initializes a new buffer from an existing bytes object.
    *      Changes to the buffer may mutate the original value.
    * @param b The bytes object to initialize the buffer with.
    * @return A new buffer.
    */
    function fromBytes(bytes b) internal pure returns(buffer memory) {
        buffer memory buf;
        buf.buf = b;
        buf.capacity = b.length;
        return buf;
    }

    function resize(buffer memory buf, uint capacity) private pure {
        bytes memory oldbuf = buf.buf;
        init(buf, capacity);
        append(buf, oldbuf);
    }

    function max(uint a, uint b) private pure returns(uint) {
        if (a > b) {
            return a;
        }
        return b;
    }

    /**
    * @dev Sets buffer length to 0.
    * @param buf The buffer to truncate.
    * @return The original buffer, for chaining..
    */
    function truncate(buffer memory buf) internal pure returns (buffer memory) {
        assembly {
            let bufptr := mload(buf)
            mstore(bufptr, 0)
        }
        return buf;
    }

    /**
    * @dev Writes a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The start offset to write to.
    * @param data The data to append.
    * @param len The number of bytes to copy.
    * @return The original buffer, for chaining.
    */
    function write(buffer memory buf, uint off, bytes data, uint len) internal pure returns(buffer memory) {
        require(len <= data.length);

        if (off + len + buf.buf.length > buf.capacity) {
            resize(buf, max(buf.capacity, len + off) * 2);
        }

        uint dest;
        uint src;
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Start address = buffer address + offset + sizeof(buffer length)
            dest := add(add(bufptr, 32), off)
            // Update buffer length if we're extending it
            if gt(add(len, off), buflen) {
                mstore(bufptr, add(len, off))
            }
            src := add(data, 32)
        }

        // Copy word-length chunks while possible
        for (; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }

        return buf;
    }

    /**
    * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @param len The number of bytes to copy.
    * @return The original buffer, for chaining.
    */
    function append(buffer memory buf, bytes data, uint len) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, len);
    }

    /**
    * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function append(buffer memory buf, bytes data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, data.length);
    }

    /**
    * @dev Writes a byte to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write the byte at.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function writeUint8(buffer memory buf, uint off, uint8 data) internal pure returns(buffer memory) {
        if (off > buf.capacity) {
            resize(buf, buf.capacity * 2);
        }

        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Address = buffer address + sizeof(buffer length) + off
            let dest := add(add(bufptr, off), 32)
            mstore8(dest, data)
            // Update buffer length if we extended it
            if eq(off, buflen) {
                mstore(bufptr, add(buflen, 1))
            }
        }
        return buf;
    }

    /**
    * @dev Appends a byte to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function appendUint8(buffer memory buf, uint8 data) internal pure returns(buffer memory) {
        return writeUint8(buf, buf.buf.length, data);
    }

    /**
    * @dev Writes up to 32 bytes to the buffer. Resizes if doing so would
    *      exceed the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @param len The number of bytes to write (left-aligned).
    * @return The original buffer, for chaining.
    */
    function write(buffer memory buf, uint off, bytes32 data, uint len) private pure returns(buffer memory) {
        if (len + off > buf.capacity) {
            resize(buf, max(buf.capacity, len) * 2);
        }

        uint mask = 256 ** len - 1;
        // Right-align data
        data = data >> (8 * (32 - len));
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Address = buffer address + sizeof(buffer length) + off + len
            let dest := add(add(bufptr, off), len)
            mstore(dest, or(and(mload(dest), not(mask)), data))
            // Update buffer length if we extended it
            if gt(add(off, len), mload(bufptr)) {
                mstore(bufptr, add(off, len))
            }
        }
        return buf;
    }

    /**
    * @dev Writes a bytes20 to the buffer. Resizes if doing so would exceed the
    *      capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function writeBytes20(buffer memory buf, uint off, bytes20 data) internal pure returns (buffer memory) {
        return write(buf, off, bytes32(data), 20);
    }

    /**
    * @dev Appends a bytes20 to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chhaining.
    */
    function appendBytes20(buffer memory buf, bytes20 data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, bytes32(data), 20);
    }

    /**
    * @dev Appends a bytes32 to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer, for chaining.
    */
    function appendBytes32(buffer memory buf, bytes32 data) internal pure returns (buffer memory) {
        return write(buf, buf.buf.length, data, 32);
    }

    /**
    * @dev Writes an integer to the buffer. Resizes if doing so would exceed
    *      the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param off The offset to write at.
    * @param data The data to append.
    * @param len The number of bytes to write (right-aligned).
    * @return The original buffer, for chaining.
    */
    function writeInt(buffer memory buf, uint off, uint data, uint len) private pure returns(buffer memory) {
        if (len + off > buf.capacity) {
            resize(buf, max(buf.capacity, len + off) * 2);
        }

        uint mask = 256 ** len - 1;
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Address = buffer address + off + sizeof(buffer length) + len
            let dest := add(add(bufptr, off), len)
            mstore(dest, or(and(mload(dest), not(mask)), data))
            // Update buffer length if we extended it
            if gt(add(off, len), mload(bufptr)) {
                mstore(bufptr, add(off, len))
            }
        }
        return buf;
    }
}

// File: @ensdomains/dnssec-oracle/contracts/RRUtils.sol

/**
* @dev RRUtils is a library that provides utilities for parsing DNS resource records.
*/
library RRUtils {
    using BytesUtils for *;
    using Buffer for *;

    /**
    * @dev Returns the number of bytes in the DNS name at 'offset' in 'self'.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The length of the DNS name at 'offset', in bytes.
    */
    function nameLength(bytes memory self, uint offset) internal pure returns(uint) {
        uint idx = offset;
        while (true) {
            assert(idx < self.length);
            uint labelLen = self.readUint8(idx);
            idx += labelLen + 1;
            if (labelLen == 0) {
                break;
            }
        }
        return idx - offset;
    }

    /**
    * @dev Returns a DNS format name at the specified offset of self.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The name.
    */
    function readName(bytes memory self, uint offset) internal pure returns(bytes memory ret) {
        uint len = nameLength(self, offset);
        return self.substring(offset, len);
    }

    /**
    * @dev Returns the number of labels in the DNS name at 'offset' in 'self'.
    * @param self The byte array to read a name from.
    * @param offset The offset to start reading at.
    * @return The number of labels in the DNS name at 'offset', in bytes.
    */
    function labelCount(bytes memory self, uint offset) internal pure returns(uint) {
        uint count = 0;
        while (true) {
            assert(offset < self.length);
            uint labelLen = self.readUint8(offset);
            offset += labelLen + 1;
            if (labelLen == 0) {
                break;
            }
            count += 1;
        }
        return count;
    }

    /**
    * @dev An iterator over resource records.
    */
    struct RRIterator {
        bytes data;
        uint offset;
        uint16 dnstype;
        uint16 class;
        uint32 ttl;
        uint rdataOffset;
        uint nextOffset;
    }

    /**
    * @dev Begins iterating over resource records.
    * @param self The byte string to read from.
    * @param offset The offset to start reading at.
    * @return An iterator object.
    */
    function iterateRRs(bytes memory self, uint offset) internal pure returns (RRIterator memory ret) {
        ret.data = self;
        ret.nextOffset = offset;
        next(ret);
    }

    /**
    * @dev Returns true iff there are more RRs to iterate.
    * @param iter The iterator to check.
    * @return True iff the iterator has finished.
    */
    function done(RRIterator memory iter) internal pure returns(bool) {
        return iter.offset >= iter.data.length;
    }

    /**
    * @dev Moves the iterator to the next resource record.
    * @param iter The iterator to advance.
    */
    function next(RRIterator memory iter) internal pure {
        iter.offset = iter.nextOffset;
        if (iter.offset >= iter.data.length) {
            return;
        }

        // Skip the name
        uint off = iter.offset + nameLength(iter.data, iter.offset);

        // Read type, class, and ttl
        iter.dnstype = iter.data.readUint16(off);
        off += 2;
        iter.class = iter.data.readUint16(off);
        off += 2;
        iter.ttl = iter.data.readUint32(off);
        off += 4;

        // Read the rdata
        uint rdataLength = iter.data.readUint16(off);
        off += 2;
        iter.rdataOffset = off;
        iter.nextOffset = off + rdataLength;
    }

    /**
    * @dev Returns the name of the current record.
    * @param iter The iterator.
    * @return A new bytes object containing the owner name from the RR.
    */
    function name(RRIterator memory iter) internal pure returns(bytes memory) {
        return iter.data.substring(iter.offset, nameLength(iter.data, iter.offset));
    }

    /**
    * @dev Returns the rdata portion of the current record.
    * @param iter The iterator.
    * @return A new bytes object containing the RR's RDATA.
    */
    function rdata(RRIterator memory iter) internal pure returns(bytes memory) {
        return iter.data.substring(iter.rdataOffset, iter.nextOffset - iter.rdataOffset);
    }

    /**
    * @dev Checks if a given RR type exists in a type bitmap.
    * @param self The byte string to read the type bitmap from.
    * @param offset The offset to start reading at.
    * @param rrtype The RR type to check for.
    * @return True if the type is found in the bitmap, false otherwise.
    */
    function checkTypeBitmap(bytes memory self, uint offset, uint16 rrtype) internal pure returns (bool) {
        uint8 typeWindow = uint8(rrtype >> 8);
        uint8 windowByte = uint8((rrtype & 0xff) / 8);
        uint8 windowBitmask = uint8(uint8(1) << (uint8(7) - uint8(rrtype & 0x7)));
        for (uint off = offset; off < self.length;) {
            uint8 window = self.readUint8(off);
            uint8 len = self.readUint8(off + 1);
            if (typeWindow < window) {
                // We've gone past our window; it's not here.
                return false;
            } else if (typeWindow == window) {
                // Check this type bitmap
                if (len * 8 <= windowByte) {
                    // Our type is past the end of the bitmap
                    return false;
                }
                return (self.readUint8(off + windowByte + 2) & windowBitmask) != 0;
            } else {
                // Skip this type bitmap
                off += len + 2;
            }
        }

        return false;
    }

    function compareNames(bytes memory self, bytes memory other) internal pure returns (int) {
        if (self.equals(other)) {
            return 0;
        }

        uint off;
        uint otheroff;
        uint prevoff;
        uint otherprevoff;
        uint counts = labelCount(self, 0);
        uint othercounts = labelCount(other, 0);

        // Keep removing labels from the front of the name until both names are equal length
        while (counts > othercounts) {
            prevoff = off;
            off = progress(self, off);
            counts--;
        }

        while (othercounts > counts) {
            otherprevoff = otheroff;
            otheroff = progress(other, otheroff);
            othercounts--;
        }

        // Compare the last nonequal labels to each other
        while (counts > 0 && !self.equals(off, other, otheroff)) {
            prevoff = off;
            off = progress(self, off);
            otherprevoff = otheroff;
            otheroff = progress(other, otheroff);
            counts -= 1;
        }

        if (off == 0) {
            return -1;
        }
        if(otheroff == 0) {
            return 1;
        }

        return self.compare(prevoff + 1, self.readUint8(prevoff), other, otherprevoff + 1, other.readUint8(otherprevoff));
    }

    function progress(bytes memory body, uint off) internal pure returns(uint) {
        return off + 1 + body.readUint8(off);
    }
}

// File: @ensdomains/ens/contracts/ENS.sol

interface ENS {

    // Logged when the owner of a node assigns a new owner to a subnode.
    event NewOwner(bytes32 indexed node, bytes32 indexed label, address owner);

    // Logged when the owner of a node transfers ownership to a new account.
    event Transfer(bytes32 indexed node, address owner);

    // Logged when the resolver for a node changes.
    event NewResolver(bytes32 indexed node, address resolver);

    // Logged when the TTL of a node changes
    event NewTTL(bytes32 indexed node, uint64 ttl);


    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) public;
    function setResolver(bytes32 node, address resolver) public;
    function setOwner(bytes32 node, address owner) public;
    function setTTL(bytes32 node, uint64 ttl) public;
    function owner(bytes32 node) public view returns (address);
    function resolver(bytes32 node) public view returns (address);
    function ttl(bytes32 node) public view returns (uint64);

}

// File: @ensdomains/ens/contracts/ENSRegistry.sol

/**
 * The ENS registry contract.
 */
contract ENSRegistry is ENS {
    struct Record {
        address owner;
        address resolver;
        uint64 ttl;
    }

    mapping (bytes32 => Record) records;

    // Permits modifications only by the owner of the specified node.
    modifier only_owner(bytes32 node) {
        require(records[node].owner == msg.sender);
        _;
    }

    /**
     * @dev Constructs a new ENS registrar.
     */
    function ENSRegistry() public {
        records[0x0].owner = msg.sender;
    }

    /**
     * @dev Transfers ownership of a node to a new address. May only be called by the current owner of the node.
     * @param node The node to transfer ownership of.
     * @param owner The address of the new owner.
     */
    function setOwner(bytes32 node, address owner) public only_owner(node) {
        Transfer(node, owner);
        records[node].owner = owner;
    }

    /**
     * @dev Transfers ownership of a subnode keccak256(node, label) to a new address. May only be called by the owner of the parent node.
     * @param node The parent node.
     * @param label The hash of the label specifying the subnode.
     * @param owner The address of the new owner.
     */
    function setSubnodeOwner(bytes32 node, bytes32 label, address owner) public only_owner(node) {
        var subnode = keccak256(node, label);
        NewOwner(node, label, owner);
        records[subnode].owner = owner;
    }

    /**
     * @dev Sets the resolver address for the specified node.
     * @param node The node to update.
     * @param resolver The address of the resolver.
     */
    function setResolver(bytes32 node, address resolver) public only_owner(node) {
        NewResolver(node, resolver);
        records[node].resolver = resolver;
    }

    /**
     * @dev Sets the TTL for the specified node.
     * @param node The node to update.
     * @param ttl The TTL in seconds.
     */
    function setTTL(bytes32 node, uint64 ttl) public only_owner(node) {
        NewTTL(node, ttl);
        records[node].ttl = ttl;
    }

    /**
     * @dev Returns the address that owns the specified node.
     * @param node The specified node.
     * @return address of the owner.
     */
    function owner(bytes32 node) public view returns (address) {
        return records[node].owner;
    }

    /**
     * @dev Returns the address of the resolver for the specified node.
     * @param node The specified node.
     * @return address of the resolver.
     */
    function resolver(bytes32 node) public view returns (address) {
        return records[node].resolver;
    }

    /**
     * @dev Returns the TTL of a node, and any records associated with it.
     * @param node The specified node.
     * @return ttl of the node.
     */
    function ttl(bytes32 node) public view returns (uint64) {
        return records[node].ttl;
    }

}

// File: contracts/DNSRegistrar.sol

/**
 * @dev An ENS registrar that allows the owner of a DNS name to claim the
 *      corresponding name in ENS.
 */
contract DNSRegistrar {
    using BytesUtils for bytes;
    using RRUtils for *;
    using Buffer for Buffer.buffer;

    uint16 constant CLASS_INET = 1;
    uint16 constant TYPE_TXT = 16;

    DNSSEC public oracle;
    ENS public ens;
    bytes public rootDomain;
    bytes32 public rootNode;

    event Claim(bytes32 indexed node, address indexed owner, bytes dnsname);

    constructor(DNSSEC _dnssec, ENS _ens, bytes _rootDomain, bytes32 _rootNode) public {
        oracle = _dnssec;
        ens = _ens;
        rootDomain = _rootDomain;
        rootNode = _rootNode;
    }

    /**
     * @dev Claims a name by proving ownership of its DNS equivalent.
     * @param name The name to claim, in DNS wire format.
     * @param proof A DNS RRSet proving ownership of the name. Must be verified
     *        in the DNSSEC oracle before calling. This RRSET must contain a TXT
     *        record for '_ens.' + name, with the value 'a=0x...'. Ownership of
     *        the name will be transferred to the address specified in the TXT
     *        record.
     */
    function claim(bytes name, bytes proof) public {
        bytes32 labelHash = getLabelHash(name);

        address addr = getOwnerAddress(name, proof);

        ens.setSubnodeOwner(rootNode, labelHash, addr);
        emit Claim(keccak256(rootNode, labelHash), addr, name);
    }

    /**
     * @dev Submits proofs to the DNSSEC oracle, then claims a name using those proofs.
     * @param name The name to claim, in DNS wire format.
     * @param input The data to be passed to the Oracle's `submitProofs` function. The last
     *        proof must be the TXT record required by the registrar.
     * @param proof The proof record for the first element in input.
     */
    function proveAndClaim(bytes name, bytes input, bytes proof) public {
        proof = oracle.submitRRSets(input, proof);
        claim(name, proof);
    }

    function getLabelHash(bytes memory name) internal view returns(bytes32) {
        uint len = name.readUint8(0);
        // Check this name is a direct subdomain of the one we're responsible for
        require(name.equals(len + 1, rootDomain));
        return name.keccak(1, len);
    }

    function getOwnerAddress(bytes memory name, bytes memory proof) internal view returns(address) {
        // Add "_ens." to the front of the name.
        Buffer.buffer memory buf;
        buf.init(name.length + 5);
        buf.append("\\x04_ens");
        buf.append(name);
        bytes20 hash;
        uint64 inserted;
        // Check the provided TXT record has been validated by the oracle
        (, inserted, hash) = oracle.rrdata(TYPE_TXT, buf.buf);
        if(hash == bytes20(0) && proof.length == 0) return 0;

        require(hash == bytes20(keccak256(proof)));

        for(RRUtils.RRIterator memory iter = proof.iterateRRs(0); !iter.done(); iter.next()) {
            require(inserted + iter.ttl >= now, "DNS record is stale; refresh or delete it before proceeding.");

            address addr = parseRR(proof, iter.rdataOffset);
            if(addr != 0) {
                return addr;
            }
        }

        return 0;
    }

    function parseRR(bytes memory rdata, uint idx) internal pure returns(address) {
        while(idx < rdata.length) {
            uint len = rdata.readUint8(idx); idx += 1;
            address addr = parseString(rdata, idx, len);
            if(addr != 0) return addr;
            idx += len;
        }

        return 0;
    }

    function parseString(bytes memory str, uint idx, uint len) internal pure returns(address) {
        // TODO: More robust parsing that handles whitespace and multiple key/value pairs
        if(str.readUint32(idx) != 0x613d3078) return 0; // 0x613d3078 == 'a=0x'
        if(len < 44) return 0;
        return hexToAddress(str, idx + 4);
    }

    function hexToAddress(bytes memory str, uint idx) internal pure returns(address) {
        if(str.length - idx < 40) return 0;
        uint ret = 0;
        for(uint i = idx; i < idx + 40; i++) {
            ret <<= 4;
            uint x = str.readUint8(i);
            if(x >= 48 && x < 58) {
                ret |= x - 48;
            } else if(x >= 65 && x < 71) {
                ret |= x - 55;
            } else if(x >= 97 && x < 103) {
                ret |= x - 87;
            } else {
                return 0;
            }
        }
        return address(ret);
    }
}