Merge "Add big integer library""

This patch merges the 3 commits in master branch into one

11 files changed, 2561 insertions, 0 deletions

diff --git a/third_party/bigint/BigInteger.cc b/third_party/bigint/BigInteger.cc
new file mode 100644
index 0000000000..bac578f974
--- /dev/null
+++ b/third_party/bigint/BigInteger.cc
@@ -0,0 +1,443 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigInteger.hh"
+
+void BigInteger::operator =(const BigInteger &x) {
+	// Calls like a = a have no effect
+	if (this == &x)
+		return;
+	// Copy sign
+	sign = x.sign;
+	// Copy the rest
+	mag = x.mag;
+}
+
+BigInteger::BigInteger(const Blk *b, Index blen, Sign s) : mag(b, blen) {
+	switch (s) {
+	case zero:
+		if (!mag.isZero())
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigInteger::BigInteger(const Blk *, Index, Sign): Cannot use a sign of zero with a nonzero magnitude";
+#endif
+		sign = zero;
+		break;
+	case positive:
+	case negative:
+		// If the magnitude is zero, force the sign to zero.
+		sign = mag.isZero() ? zero : s;
+		break;
+	default:
+		/* g++ seems to be optimizing out this case on the assumption
+		 * that the sign is a valid member of the enumeration.  Oh well. */
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigInteger::BigInteger(const Blk *, Index, Sign): Invalid sign";
+#endif
+	}
+}
+
+BigInteger::BigInteger(const BigUnsigned &x, Sign s) : mag(x) {
+	switch (s) {
+	case zero:
+		if (!mag.isZero())
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Cannot use a sign of zero with a nonzero magnitude";
+#endif
+		sign = zero;
+		break;
+	case positive:
+	case negative:
+		// If the magnitude is zero, force the sign to zero.
+		sign = mag.isZero() ? zero : s;
+		break;
+	default:
+		/* g++ seems to be optimizing out this case on the assumption
+		 * that the sign is a valid member of the enumeration.  Oh well. */
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigInteger::BigInteger(const BigUnsigned &, Sign): Invalid sign";
+#endif
+	}
+}
+
+/* CONSTRUCTION FROM PRIMITIVE INTEGERS
+ * Same idea as in BigUnsigned.cc, except that negative input results in a
+ * negative BigInteger instead of an exception. */
+
+// Done longhand to let us use initialization.
+BigInteger::BigInteger(unsigned long  x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+BigInteger::BigInteger(unsigned int   x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+BigInteger::BigInteger(unsigned short x) : mag(x) { sign = mag.isZero() ? zero : positive; }
+
+// For signed input, determine the desired magnitude and sign separately.
+
+namespace {
+	template <class X, class UX>
+	BigInteger::Blk magOf(X x) {
+		/* UX(...) cast needed to stop short(-2^15), which negates to
+		 * itself, from sign-extending in the conversion to Blk. */
+		return BigInteger::Blk(x < 0 ? UX(-x) : x);
+	}
+	template <class X>
+	BigInteger::Sign signOf(X x) {
+		return (x == 0) ? BigInteger::zero
+			: (x > 0) ? BigInteger::positive
+			: BigInteger::negative;
+	}
+}
+
+BigInteger::BigInteger(long  x) : sign(signOf(x)), mag(magOf<long , unsigned long >(x)) {}
+BigInteger::BigInteger(int   x) : sign(signOf(x)), mag(magOf<int  , unsigned int  >(x)) {}
+BigInteger::BigInteger(short x) : sign(signOf(x)), mag(magOf<short, unsigned short>(x)) {}
+
+// CONVERSION TO PRIMITIVE INTEGERS
+
+/* Reuse BigUnsigned's conversion to an unsigned primitive integer.
+ * The friend is a separate function rather than
+ * BigInteger::convertToUnsignedPrimitive to avoid requiring BigUnsigned to
+ * declare BigInteger. */
+template <class X>
+inline X convertBigUnsignedToPrimitiveAccess(const BigUnsigned &a) {
+	return a.convertToPrimitive<X>();
+}
+
+template <class X>
+X BigInteger::convertToUnsignedPrimitive() const {
+	if (sign == negative)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigInteger::to<Primitive>: "
+			"Cannot convert a negative integer to an unsigned type";
+#endif
+	else
+		return convertBigUnsignedToPrimitiveAccess<X>(mag);
+}
+
+/* Similar to BigUnsigned::convertToPrimitive, but split into two cases for
+ * nonnegative and negative numbers. */
+template <class X, class UX>
+X BigInteger::convertToSignedPrimitive() const {
+	if (sign == zero)
+		return 0;
+	else if (mag.getLength() == 1) {
+		// The single block might fit in an X.  Try the conversion.
+		Blk b = mag.getBlock(0);
+		if (sign == positive) {
+			X x = X(b);
+			if (x >= 0 && Blk(x) == b)
+				return x;
+		} else {
+			X x = -X(b);
+			/* UX(...) needed to avoid rejecting conversion of
+			 * -2^15 to a short. */
+			if (x < 0 && Blk(UX(-x)) == b)
+				return x;
+		}
+		// Otherwise fall through.
+	}
+#ifdef FOXIT_CHROME_BUILD
+    abort();
+#else
+	throw "BigInteger::to<Primitive>: "
+		"Value is too big to fit in the requested type";
+#endif
+}
+
+unsigned long  BigInteger::toUnsignedLong () const { return convertToUnsignedPrimitive<unsigned long >       (); }
+unsigned int   BigInteger::toUnsignedInt  () const { return convertToUnsignedPrimitive<unsigned int  >       (); }
+unsigned short BigInteger::toUnsignedShort() const { return convertToUnsignedPrimitive<unsigned short>       (); }
+long           BigInteger::toLong         () const { return convertToSignedPrimitive  <long , unsigned long> (); }
+int            BigInteger::toInt          () const { return convertToSignedPrimitive  <int  , unsigned int>  (); }
+short          BigInteger::toShort        () const { return convertToSignedPrimitive  <short, unsigned short>(); }
+
+// COMPARISON
+BigInteger::CmpRes BigInteger::compareTo(const BigInteger &x) const {
+	// A greater sign implies a greater number
+	if (sign < x.sign)
+		return less;
+	else if (sign > x.sign)
+		return greater;
+	else switch (sign) {
+		// If the signs are the same...
+	case zero:
+		return equal; // Two zeros are equal
+	case positive:
+		// Compare the magnitudes
+		return mag.compareTo(x.mag);
+	case negative:
+		// Compare the magnitudes, but return the opposite result
+		return CmpRes(-mag.compareTo(x.mag));
+	default:
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigInteger internal error";
+#endif
+	}
+}
+
+/* COPY-LESS OPERATIONS
+ * These do some messing around to determine the sign of the result,
+ * then call one of BigUnsigned's copy-less operations. */
+
+// See remarks about aliased calls in BigUnsigned.cc .
+#define DTRT_ALIASED(cond, op) \
+	if (cond) { \
+		BigInteger tmpThis; \
+		tmpThis.op; \
+		*this = tmpThis; \
+		return; \
+	}
+
+void BigInteger::add(const BigInteger &a, const BigInteger &b) {
+	DTRT_ALIASED(this == &a || this == &b, add(a, b));
+	// If one argument is zero, copy the other.
+	if (a.sign == zero)
+		operator =(b);
+	else if (b.sign == zero)
+		operator =(a);
+	// If the arguments have the same sign, take the
+	// common sign and add their magnitudes.
+	else if (a.sign == b.sign) {
+		sign = a.sign;
+		mag.add(a.mag, b.mag);
+	} else {
+		// Otherwise, their magnitudes must be compared.
+		switch (a.mag.compareTo(b.mag)) {
+		case equal:
+			// If their magnitudes are the same, copy zero.
+			mag = 0;
+			sign = zero;
+			break;
+			// Otherwise, take the sign of the greater, and subtract
+			// the lesser magnitude from the greater magnitude.
+		case greater:
+			sign = a.sign;
+			mag.subtract(a.mag, b.mag);
+			break;
+		case less:
+			sign = b.sign;
+			mag.subtract(b.mag, a.mag);
+			break;
+		}
+	}
+}
+
+void BigInteger::subtract(const BigInteger &a, const BigInteger &b) {
+	// Notice that this routine is identical to BigInteger::add,
+	// if one replaces b.sign by its opposite.
+	DTRT_ALIASED(this == &a || this == &b, subtract(a, b));
+	// If a is zero, copy b and flip its sign.  If b is zero, copy a.
+	if (a.sign == zero) {
+		mag = b.mag;
+		// Take the negative of _b_'s, sign, not ours.
+		// Bug pointed out by Sam Larkin on 2005.03.30.
+		sign = Sign(-b.sign);
+	} else if (b.sign == zero)
+		operator =(a);
+	// If their signs differ, take a.sign and add the magnitudes.
+	else if (a.sign != b.sign) {
+		sign = a.sign;
+		mag.add(a.mag, b.mag);
+	} else {
+		// Otherwise, their magnitudes must be compared.
+		switch (a.mag.compareTo(b.mag)) {
+			// If their magnitudes are the same, copy zero.
+		case equal:
+			mag = 0;
+			sign = zero;
+			break;
+			// If a's magnitude is greater, take a.sign and
+			// subtract a from b.
+		case greater:
+			sign = a.sign;
+			mag.subtract(a.mag, b.mag);
+			break;
+			// If b's magnitude is greater, take the opposite
+			// of b.sign and subtract b from a.
+		case less:
+			sign = Sign(-b.sign);
+			mag.subtract(b.mag, a.mag);
+			break;
+		}
+	}
+}
+
+void BigInteger::multiply(const BigInteger &a, const BigInteger &b) {
+	DTRT_ALIASED(this == &a || this == &b, multiply(a, b));
+	// If one object is zero, copy zero and return.
+	if (a.sign == zero || b.sign == zero) {
+		sign = zero;
+		mag = 0;
+		return;
+	}
+	// If the signs of the arguments are the same, the result
+	// is positive, otherwise it is negative.
+	sign = (a.sign == b.sign) ? positive : negative;
+	// Multiply the magnitudes.
+	mag.multiply(a.mag, b.mag);
+}
+
+/*
+ * DIVISION WITH REMAINDER
+ * Please read the comments before the definition of
+ * `BigUnsigned::divideWithRemainder' in `BigUnsigned.cc' for lots of
+ * information you should know before reading this function.
+ *
+ * Following Knuth, I decree that x / y is to be
+ * 0 if y==0 and floor(real-number x / y) if y!=0.
+ * Then x % y shall be x - y*(integer x / y).
+ *
+ * Note that x = y * (x / y) + (x % y) always holds.
+ * In addition, (x % y) is from 0 to y - 1 if y > 0,
+ * and from -(|y| - 1) to 0 if y < 0.  (x % y) = x if y = 0.
+ *
+ * Examples: (q = a / b, r = a % b)
+ *	a	b	q	r
+ *	===	===	===	===
+ *	4	3	1	1
+ *	-4	3	-2	2
+ *	4	-3	-2	-2
+ *	-4	-3	1	-1
+ */
+void BigInteger::divideWithRemainder(const BigInteger &b, BigInteger &q) {
+	// Defend against aliased calls;
+	// same idea as in BigUnsigned::divideWithRemainder .
+	if (this == &q)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigInteger::divideWithRemainder: Cannot write quotient and remainder into the same variable";
+#endif
+	if (this == &b || &q == &b) {
+		BigInteger tmpB(b);
+		divideWithRemainder(tmpB, q);
+		return;
+	}
+
+	// Division by zero gives quotient 0 and remainder *this
+	if (b.sign == zero) {
+		q.mag = 0;
+		q.sign = zero;
+		return;
+	}
+	// 0 / b gives quotient 0 and remainder 0
+	if (sign == zero) {
+		q.mag = 0;
+		q.sign = zero;
+		return;
+	}
+
+	// Here *this != 0, b != 0.
+
+	// Do the operands have the same sign?
+	if (sign == b.sign) {
+		// Yes: easy case.  Quotient is zero or positive.
+		q.sign = positive;
+	} else {
+		// No: harder case.  Quotient is negative.
+		q.sign = negative;
+		// Decrease the magnitude of the dividend by one.
+		mag--;
+		/*
+		 * We tinker with the dividend before and with the
+		 * quotient and remainder after so that the result
+		 * comes out right.  To see why it works, consider the following
+		 * list of examples, where A is the magnitude-decreased
+		 * a, Q and R are the results of BigUnsigned division
+		 * with remainder on A and |b|, and q and r are the
+		 * final results we want:
+		 *
+		 *	a	A	b	Q	R	q	r
+		 *	-3	-2	3	0	2	-1	0
+		 *	-4	-3	3	1	0	-2	2
+		 *	-5	-4	3	1	1	-2	1
+		 *	-6	-5	3	1	2	-2	0
+		 *
+		 * It appears that we need a total of 3 corrections:
+		 * Decrease the magnitude of a to get A.  Increase the
+		 * magnitude of Q to get q (and make it negative).
+		 * Find r = (b - 1) - R and give it the desired sign.
+		 */
+	}
+
+	// Divide the magnitudes.
+	mag.divideWithRemainder(b.mag, q.mag);
+
+	if (sign != b.sign) {
+		// More for the harder case (as described):
+		// Increase the magnitude of the quotient by one.
+		q.mag++;
+		// Modify the remainder.
+		mag.subtract(b.mag, mag);
+		mag--;
+	}
+
+	// Sign of the remainder is always the sign of the divisor b.
+	sign = b.sign;
+
+	// Set signs to zero as necessary.  (Thanks David Allen!)
+	if (mag.isZero())
+		sign = zero;
+	if (q.mag.isZero())
+		q.sign = zero;
+
+	// WHEW!!!
+}
+
+// Negation
+void BigInteger::negate(const BigInteger &a) {
+	DTRT_ALIASED(this == &a, negate(a));
+	// Copy a's magnitude
+	mag = a.mag;
+	// Copy the opposite of a.sign
+	sign = Sign(-a.sign);
+}
+
+// INCREMENT/DECREMENT OPERATORS
+
+// Prefix increment
+void BigInteger::operator ++() {
+	if (sign == negative) {
+		mag--;
+		if (mag == 0)
+			sign = zero;
+	} else {
+		mag++;
+		sign = positive; // if not already
+	}
+}
+
+// Postfix increment: same as prefix
+void BigInteger::operator ++(int) {
+	operator ++();
+}
+
+// Prefix decrement
+void BigInteger::operator --() {
+	if (sign == positive) {
+		mag--;
+		if (mag == 0)
+			sign = zero;
+	} else {
+		mag++;
+		sign = negative;
+	}
+}
+
+// Postfix decrement: same as prefix
+void BigInteger::operator --(int) {
+	operator --();
+}
+
diff --git a/third_party/bigint/BigInteger.hh b/third_party/bigint/BigInteger.hh
new file mode 100644
index 0000000000..a239d3c954
--- /dev/null
+++ b/third_party/bigint/BigInteger.hh
@@ -0,0 +1,241 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGINTEGER_H
+#define BIGINTEGER_H
+
+#include "BigUnsigned.hh"
+
+/* A BigInteger object represents a signed integer of size limited only by
+ * available memory.  BigUnsigneds support most mathematical operators and can
+ * be converted to and from most primitive integer types.
+ *
+ * A BigInteger is just an aggregate of a BigUnsigned and a sign.  (It is no
+ * longer derived from BigUnsigned because that led to harmful implicit
+ * conversions.) */
+class BigInteger {
+
+public:
+	typedef BigUnsigned::Blk Blk;
+	typedef BigUnsigned::Index Index;
+	typedef BigUnsigned::CmpRes CmpRes;
+	static const CmpRes
+		less    = BigUnsigned::less   ,
+		equal   = BigUnsigned::equal  ,
+		greater = BigUnsigned::greater;
+	// Enumeration for the sign of a BigInteger.
+	enum Sign { negative = -1, zero = 0, positive = 1 };
+
+protected:
+	Sign sign;
+	BigUnsigned mag;
+
+public:
+	// Constructs zero.
+	BigInteger() : sign(zero), mag() {}
+
+	// Copy constructor
+	BigInteger(const BigInteger &x) : sign(x.sign), mag(x.mag) {};
+
+	// Assignment operator
+	void operator=(const BigInteger &x);
+
+	// Constructor that copies from a given array of blocks with a sign.
+	BigInteger(const Blk *b, Index blen, Sign s);
+
+	// Nonnegative constructor that copies from a given array of blocks.
+	BigInteger(const Blk *b, Index blen) : mag(b, blen) {
+		sign = mag.isZero() ? zero : positive;
+	}
+
+	// Constructor from a BigUnsigned and a sign
+	BigInteger(const BigUnsigned &x, Sign s);
+
+	// Nonnegative constructor from a BigUnsigned
+	BigInteger(const BigUnsigned &x) : mag(x) {
+		sign = mag.isZero() ? zero : positive;
+	}
+
+	// Constructors from primitive integer types
+	BigInteger(unsigned long  x);
+	BigInteger(         long  x);
+	BigInteger(unsigned int   x);
+	BigInteger(         int   x);
+	BigInteger(unsigned short x);
+	BigInteger(         short x);
+
+	/* Converters to primitive integer types
+	 * The implicit conversion operators caused trouble, so these are now
+	 * named. */
+	unsigned long  toUnsignedLong () const;
+	long           toLong         () const;
+	unsigned int   toUnsignedInt  () const;
+	int            toInt          () const;
+	unsigned short toUnsignedShort() const;
+	short          toShort        () const;
+protected:
+	// Helper
+	template <class X> X convertToUnsignedPrimitive() const;
+	template <class X, class UX> X convertToSignedPrimitive() const;
+public:
+
+	// ACCESSORS
+	Sign getSign() const { return sign; }
+	/* The client can't do any harm by holding a read-only reference to the
+	 * magnitude. */
+	const BigUnsigned &getMagnitude() const { return mag; }
+
+	// Some accessors that go through to the magnitude
+	Index getLength() const { return mag.getLength(); }
+	Index getCapacity() const { return mag.getCapacity(); }
+	Blk getBlock(Index i) const { return mag.getBlock(i); }
+	bool isZero() const { return sign == zero; } // A bit special
+
+	// COMPARISONS
+
+	// Compares this to x like Perl's <=>
+	CmpRes compareTo(const BigInteger &x) const;
+
+	// Ordinary comparison operators
+	bool operator ==(const BigInteger &x) const {
+		return sign == x.sign && mag == x.mag;
+	}
+	bool operator !=(const BigInteger &x) const { return !operator ==(x); };
+	bool operator < (const BigInteger &x) const { return compareTo(x) == less   ; }
+	bool operator <=(const BigInteger &x) const { return compareTo(x) != greater; }
+	bool operator >=(const BigInteger &x) const { return compareTo(x) != less   ; }
+	bool operator > (const BigInteger &x) const { return compareTo(x) == greater; }
+
+	// OPERATORS -- See the discussion in BigUnsigned.hh.
+	void add     (const BigInteger &a, const BigInteger &b);
+	void subtract(const BigInteger &a, const BigInteger &b);
+	void multiply(const BigInteger &a, const BigInteger &b);
+	/* See the comment on BigUnsigned::divideWithRemainder.  Semantics
+	 * differ from those of primitive integers when negatives and/or zeros
+	 * are involved. */
+	void divideWithRemainder(const BigInteger &b, BigInteger &q);
+	void negate(const BigInteger &a);
+	
+	/* Bitwise operators are not provided for BigIntegers.  Use
+	 * getMagnitude to get the magnitude and operate on that instead. */
+
+	BigInteger operator +(const BigInteger &x) const;
+	BigInteger operator -(const BigInteger &x) const;
+	BigInteger operator *(const BigInteger &x) const;
+	BigInteger operator /(const BigInteger &x) const;
+	BigInteger operator %(const BigInteger &x) const;
+	BigInteger operator -() const;
+
+	void operator +=(const BigInteger &x);
+	void operator -=(const BigInteger &x);
+	void operator *=(const BigInteger &x);
+	void operator /=(const BigInteger &x);
+	void operator %=(const BigInteger &x);
+	void flipSign();
+
+	// INCREMENT/DECREMENT OPERATORS
+	void operator ++(   );
+	void operator ++(int);
+	void operator --(   );
+	void operator --(int);
+};
+
+// NORMAL OPERATORS
+/* These create an object to hold the result and invoke
+ * the appropriate put-here operation on it, passing
+ * this and x.  The new object is then returned. */
+inline BigInteger BigInteger::operator +(const BigInteger &x) const {
+	BigInteger ans;
+	ans.add(*this, x);
+	return ans;
+}
+inline BigInteger BigInteger::operator -(const BigInteger &x) const {
+	BigInteger ans;
+	ans.subtract(*this, x);
+	return ans;
+}
+inline BigInteger BigInteger::operator *(const BigInteger &x) const {
+	BigInteger ans;
+	ans.multiply(*this, x);
+	return ans;
+}
+inline BigInteger BigInteger::operator /(const BigInteger &x) const {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigInteger::operator /: division by zero";
+#endif
+	BigInteger q, r;
+	r = *this;
+	r.divideWithRemainder(x, q);
+	return q;
+}
+inline BigInteger BigInteger::operator %(const BigInteger &x) const {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigInteger::operator %: division by zero";
+#endif
+	BigInteger q, r;
+	r = *this;
+	r.divideWithRemainder(x, q);
+	return r;
+}
+inline BigInteger BigInteger::operator -() const {
+	BigInteger ans;
+	ans.negate(*this);
+	return ans;
+}
+
+/*
+ * ASSIGNMENT OPERATORS
+ * 
+ * Now the responsibility for making a temporary copy if necessary
+ * belongs to the put-here operations.  See Assignment Operators in
+ * BigUnsigned.hh.
+ */
+inline void BigInteger::operator +=(const BigInteger &x) {
+	add(*this, x);
+}
+inline void BigInteger::operator -=(const BigInteger &x) {
+	subtract(*this, x);
+}
+inline void BigInteger::operator *=(const BigInteger &x) {
+	multiply(*this, x);
+}
+inline void BigInteger::operator /=(const BigInteger &x) {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigInteger::operator /=: division by zero";
+#endif
+	/* The following technique is slightly faster than copying *this first
+	 * when x is large. */
+	BigInteger q;
+	divideWithRemainder(x, q);
+	// *this contains the remainder, but we overwrite it with the quotient.
+	*this = q;
+}
+inline void BigInteger::operator %=(const BigInteger &x) {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigInteger::operator %=: division by zero";
+#endif
+	BigInteger q;
+	// Mods *this by x.  Don't care about quotient left in q.
+	divideWithRemainder(x, q);
+}
+// This one is trivial
+inline void BigInteger::flipSign() {
+	sign = Sign(-sign);
+}
+
+#endif
diff --git a/third_party/bigint/BigIntegerLibrary.hh b/third_party/bigint/BigIntegerLibrary.hh
new file mode 100644
index 0000000000..2027804dfb
--- /dev/null
+++ b/third_party/bigint/BigIntegerLibrary.hh
@@ -0,0 +1,14 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+// This header file includes all of the library header files.
+
+#include "NumberlikeArray.hh"
+#include "BigUnsigned.hh"
+#include "BigInteger.hh"
+#include "BigUnsignedInABase.hh"
+#include "BigIntegerUtils.hh"
+
diff --git a/third_party/bigint/BigIntegerUtils.cc b/third_party/bigint/BigIntegerUtils.cc
new file mode 100644
index 0000000000..fac8ac34b1
--- /dev/null
+++ b/third_party/bigint/BigIntegerUtils.cc
@@ -0,0 +1,60 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigIntegerUtils.hh"
+#include "BigUnsignedInABase.hh"
+
+std::string bigUnsignedToString(const BigUnsigned &x) {
+	return std::string(BigUnsignedInABase(x, 10));
+}
+
+std::string bigIntegerToString(const BigInteger &x) {
+	return (x.getSign() == BigInteger::negative)
+		? (std::string("-") + bigUnsignedToString(x.getMagnitude()))
+		: (bigUnsignedToString(x.getMagnitude()));
+}
+
+BigUnsigned stringToBigUnsigned(const std::string &s) {
+	return BigUnsigned(BigUnsignedInABase(s, 10));
+}
+
+BigInteger stringToBigInteger(const std::string &s) {
+	// Recognize a sign followed by a BigUnsigned.
+	return (s[0] == '-') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)), BigInteger::negative)
+		: (s[0] == '+') ? BigInteger(stringToBigUnsigned(s.substr(1, s.length() - 1)))
+		: BigInteger(stringToBigUnsigned(s));
+}
+
+std::ostream &operator <<(std::ostream &os, const BigUnsigned &x) {
+	BigUnsignedInABase::Base base;
+	long osFlags = os.flags();
+	if (osFlags & os.dec)
+		base = 10;
+	else if (osFlags & os.hex) {
+		base = 16;
+		if (osFlags & os.showbase)
+			os << "0x";
+	} else if (osFlags & os.oct) {
+		base = 8;
+		if (osFlags & os.showbase)
+			os << '0';
+	} else
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "std::ostream << BigUnsigned: Could not determine the desired base from output-stream flags";
+#endif
+	std::string s = std::string(BigUnsignedInABase(x, base));
+	os << s;
+	return os;
+}
+
+std::ostream &operator <<(std::ostream &os, const BigInteger &x) {
+	if (x.getSign() == BigInteger::negative)
+		os << '-';
+	os << x.getMagnitude();
+	return os;
+}
diff --git a/third_party/bigint/BigIntegerUtils.hh b/third_party/bigint/BigIntegerUtils.hh
new file mode 100644
index 0000000000..d2f81f48ab
--- /dev/null
+++ b/third_party/bigint/BigIntegerUtils.hh
@@ -0,0 +1,78 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGINTEGERUTILS_H
+#define BIGINTEGERUTILS_H
+
+#include "BigInteger.hh"
+#include <string>
+#include <iostream>
+
+/* This file provides:
+ * - Convenient std::string <-> BigUnsigned/BigInteger conversion routines
+ * - std::ostream << operators for BigUnsigned/BigInteger */
+
+// std::string conversion routines.  Base 10 only.
+std::string bigUnsignedToString(const BigUnsigned &x);
+std::string bigIntegerToString(const BigInteger &x);
+BigUnsigned stringToBigUnsigned(const std::string &s);
+BigInteger stringToBigInteger(const std::string &s);
+
+// Creates a BigInteger from data such as `char's; read below for details.
+template <class T>
+BigInteger dataToBigInteger(const T* data, BigInteger::Index length, BigInteger::Sign sign);
+
+// Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'.
+std::ostream &operator <<(std::ostream &os, const BigUnsigned &x);
+
+// Outputs x to os, obeying the flags `dec', `hex', `bin', and `showbase'.
+// My somewhat arbitrary policy: a negative sign comes before a base indicator (like -0xFF).
+std::ostream &operator <<(std::ostream &os, const BigInteger &x);
+
+// BEGIN TEMPLATE DEFINITIONS.
+
+/*
+ * Converts binary data to a BigInteger.
+ * Pass an array `data', its length, and the desired sign.
+ *
+ * Elements of `data' may be of any type `T' that has the following
+ * two properties (this includes almost all integral types):
+ *
+ * (1) `sizeof(T)' correctly gives the amount of binary data in one
+ * value of `T' and is a factor of `sizeof(Blk)'.
+ *
+ * (2) When a value of `T' is casted to a `Blk', the low bytes of
+ * the result contain the desired binary data.
+ */
+template <class T>
+BigInteger dataToBigInteger(const T* data, BigInteger::Index length, BigInteger::Sign sign) {
+	// really ceiling(numBytes / sizeof(BigInteger::Blk))
+	unsigned int pieceSizeInBits = 8 * sizeof(T);
+	unsigned int piecesPerBlock = sizeof(BigInteger::Blk) / sizeof(T);
+	unsigned int numBlocks = (length + piecesPerBlock - 1) / piecesPerBlock;
+
+	// Allocate our block array
+	BigInteger::Blk *blocks = new BigInteger::Blk[numBlocks];
+
+	BigInteger::Index blockNum, pieceNum, pieceNumHere;
+
+	// Convert
+	for (blockNum = 0, pieceNum = 0; blockNum < numBlocks; blockNum++) {
+		BigInteger::Blk curBlock = 0;
+		for (pieceNumHere = 0; pieceNumHere < piecesPerBlock && pieceNum < length;
+			pieceNumHere++, pieceNum++)
+			curBlock |= (BigInteger::Blk(data[pieceNum]) << (pieceSizeInBits * pieceNumHere));
+		blocks[blockNum] = curBlock;
+	}
+
+	// Create the BigInteger.
+	BigInteger x(blocks, numBlocks, sign);
+
+	delete [] blocks;
+	return x;
+}
+
+#endif
diff --git a/third_party/bigint/BigUnsigned.cc b/third_party/bigint/BigUnsigned.cc
new file mode 100644
index 0000000000..863fadcb39
--- /dev/null
+++ b/third_party/bigint/BigUnsigned.cc
@@ -0,0 +1,727 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigUnsigned.hh"
+
+// Memory management definitions have moved to the bottom of NumberlikeArray.hh.
+
+// The templates used by these constructors and converters are at the bottom of
+// BigUnsigned.hh.
+
+BigUnsigned::BigUnsigned(unsigned long  x) { initFromPrimitive      (x); }
+BigUnsigned::BigUnsigned(unsigned int   x) { initFromPrimitive      (x); }
+BigUnsigned::BigUnsigned(unsigned short x) { initFromPrimitive      (x); }
+BigUnsigned::BigUnsigned(         long  x) { initFromSignedPrimitive(x); }
+BigUnsigned::BigUnsigned(         int   x) { initFromSignedPrimitive(x); }
+BigUnsigned::BigUnsigned(         short x) { initFromSignedPrimitive(x); }
+
+unsigned long  BigUnsigned::toUnsignedLong () const { return convertToPrimitive      <unsigned long >(); }
+unsigned int   BigUnsigned::toUnsignedInt  () const { return convertToPrimitive      <unsigned int  >(); }
+unsigned short BigUnsigned::toUnsignedShort() const { return convertToPrimitive      <unsigned short>(); }
+long           BigUnsigned::toLong         () const { return convertToSignedPrimitive<         long >(); }
+int            BigUnsigned::toInt          () const { return convertToSignedPrimitive<         int  >(); }
+short          BigUnsigned::toShort        () const { return convertToSignedPrimitive<         short>(); }
+
+// BIT/BLOCK ACCESSORS
+
+void BigUnsigned::setBlock(Index i, Blk newBlock) {
+	if (newBlock == 0) {
+		if (i < len) {
+			blk[i] = 0;
+			zapLeadingZeros();
+		}
+		// If i >= len, no effect.
+	} else {
+		if (i >= len) {
+			// The nonzero block extends the number.
+			allocateAndCopy(i+1);
+			// Zero any added blocks that we aren't setting.
+			for (Index j = len; j < i; j++)
+				blk[j] = 0;
+			len = i+1;
+		}
+		blk[i] = newBlock;
+	}
+}
+
+/* Evidently the compiler wants BigUnsigned:: on the return type because, at
+ * that point, it hasn't yet parsed the BigUnsigned:: on the name to get the
+ * proper scope. */
+BigUnsigned::Index BigUnsigned::bitLength() const {
+	if (isZero())
+		return 0;
+	else {
+		Blk leftmostBlock = getBlock(len - 1);
+		Index leftmostBlockLen = 0;
+		while (leftmostBlock != 0) {
+			leftmostBlock >>= 1;
+			leftmostBlockLen++;
+		}
+		return leftmostBlockLen + (len - 1) * N;
+	}
+}
+
+void BigUnsigned::setBit(Index bi, bool newBit) {
+	Index blockI = bi / N;
+	Blk block = getBlock(blockI), mask = Blk(1) << (bi % N);
+	block = newBit ? (block | mask) : (block & ~mask);
+	setBlock(blockI, block);
+}
+
+// COMPARISON
+BigUnsigned::CmpRes BigUnsigned::compareTo(const BigUnsigned &x) const {
+	// A bigger length implies a bigger number.
+	if (len < x.len)
+		return less;
+	else if (len > x.len)
+		return greater;
+	else {
+		// Compare blocks one by one from left to right.
+		Index i = len;
+		while (i > 0) {
+			i--;
+			if (blk[i] == x.blk[i])
+				continue;
+			else if (blk[i] > x.blk[i])
+				return greater;
+			else
+				return less;
+		}
+		// If no blocks differed, the numbers are equal.
+		return equal;
+	}
+}
+
+// COPY-LESS OPERATIONS
+
+/*
+ * On most calls to copy-less operations, it's safe to read the inputs little by
+ * little and write the outputs little by little.  However, if one of the
+ * inputs is coming from the same variable into which the output is to be
+ * stored (an "aliased" call), we risk overwriting the input before we read it.
+ * In this case, we first compute the result into a temporary BigUnsigned
+ * variable and then copy it into the requested output variable *this.
+ * Each put-here operation uses the DTRT_ALIASED macro (Do The Right Thing on
+ * aliased calls) to generate code for this check.
+ * 
+ * I adopted this approach on 2007.02.13 (see Assignment Operators in
+ * BigUnsigned.hh).  Before then, put-here operations rejected aliased calls
+ * with an exception.  I think doing the right thing is better.
+ * 
+ * Some of the put-here operations can probably handle aliased calls safely
+ * without the extra copy because (for example) they process blocks strictly
+ * right-to-left.  At some point I might determine which ones don't need the
+ * copy, but my reasoning would need to be verified very carefully.  For now
+ * I'll leave in the copy.
+ */
+#define DTRT_ALIASED(cond, op) \
+	if (cond) { \
+		BigUnsigned tmpThis; \
+		tmpThis.op; \
+		*this = tmpThis; \
+		return; \
+	}
+
+
+
+void BigUnsigned::add(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, add(a, b));
+	// If one argument is zero, copy the other.
+	if (a.len == 0) {
+		operator =(b);
+		return;
+	} else if (b.len == 0) {
+		operator =(a);
+		return;
+	}
+	// Some variables...
+	// Carries in and out of an addition stage
+	bool carryIn, carryOut;
+	Blk temp;
+	Index i;
+	// a2 points to the longer input, b2 points to the shorter
+	const BigUnsigned *a2, *b2;
+	if (a.len >= b.len) {
+		a2 = &a;
+		b2 = &b;
+	} else {
+		a2 = &b;
+		b2 = &a;
+	}
+	// Set prelimiary length and make room in this BigUnsigned
+	len = a2->len + 1;
+	allocate(len);
+	// For each block index that is present in both inputs...
+	for (i = 0, carryIn = false; i < b2->len; i++) {
+		// Add input blocks
+		temp = a2->blk[i] + b2->blk[i];
+		// If a rollover occurred, the result is less than either input.
+		// This test is used many times in the BigUnsigned code.
+		carryOut = (temp < a2->blk[i]);
+		// If a carry was input, handle it
+		if (carryIn) {
+			temp++;
+			carryOut |= (temp == 0);
+		}
+		blk[i] = temp; // Save the addition result
+		carryIn = carryOut; // Pass the carry along
+	}
+	// If there is a carry left over, increase blocks until
+	// one does not roll over.
+	for (; i < a2->len && carryIn; i++) {
+		temp = a2->blk[i] + 1;
+		carryIn = (temp == 0);
+		blk[i] = temp;
+	}
+	// If the carry was resolved but the larger number
+	// still has blocks, copy them over.
+	for (; i < a2->len; i++)
+		blk[i] = a2->blk[i];
+	// Set the extra block if there's still a carry, decrease length otherwise
+	if (carryIn)
+		blk[i] = 1;
+	else
+		len--;
+}
+
+void BigUnsigned::subtract(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, subtract(a, b));
+	if (b.len == 0) {
+		// If b is zero, copy a.
+		operator =(a);
+		return;
+	} else if (a.len < b.len)
+		// If a is shorter than b, the result is negative.
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned::subtract: "
+			"Negative result in unsigned calculation";
+#endif
+	// Some variables...
+	bool borrowIn, borrowOut;
+	Blk temp;
+	Index i;
+	// Set preliminary length and make room
+	len = a.len;
+	allocate(len);
+	// For each block index that is present in both inputs...
+	for (i = 0, borrowIn = false; i < b.len; i++) {
+		temp = a.blk[i] - b.blk[i];
+		// If a reverse rollover occurred,
+		// the result is greater than the block from a.
+		borrowOut = (temp > a.blk[i]);
+		// Handle an incoming borrow
+		if (borrowIn) {
+			borrowOut |= (temp == 0);
+			temp--;
+		}
+		blk[i] = temp; // Save the subtraction result
+		borrowIn = borrowOut; // Pass the borrow along
+	}
+	// If there is a borrow left over, decrease blocks until
+	// one does not reverse rollover.
+	for (; i < a.len && borrowIn; i++) {
+		borrowIn = (a.blk[i] == 0);
+		blk[i] = a.blk[i] - 1;
+	}
+	/* If there's still a borrow, the result is negative.
+	 * Throw an exception, but zero out this object so as to leave it in a
+	 * predictable state. */
+	if (borrowIn) {
+		len = 0;
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned::subtract: Negative result in unsigned calculation";
+#endif
+	} else
+		// Copy over the rest of the blocks
+		for (; i < a.len; i++)
+			blk[i] = a.blk[i];
+	// Zap leading zeros
+	zapLeadingZeros();
+}
+
+/*
+ * About the multiplication and division algorithms:
+ *
+ * I searched unsucessfully for fast C++ built-in operations like the `b_0'
+ * and `c_0' Knuth describes in Section 4.3.1 of ``The Art of Computer
+ * Programming'' (replace `place' by `Blk'):
+ *
+ *    ``b_0[:] multiplication of a one-place integer by another one-place
+ *      integer, giving a two-place answer;
+ *
+ *    ``c_0[:] division of a two-place integer by a one-place integer,
+ *      provided that the quotient is a one-place integer, and yielding
+ *      also a one-place remainder.''
+ *
+ * I also missed his note that ``[b]y adjusting the word size, if
+ * necessary, nearly all computers will have these three operations
+ * available'', so I gave up on trying to use algorithms similar to his.
+ * A future version of the library might include such algorithms; I
+ * would welcome contributions from others for this.
+ *
+ * I eventually decided to use bit-shifting algorithms.  To multiply `a'
+ * and `b', we zero out the result.  Then, for each `1' bit in `a', we
+ * shift `b' left the appropriate amount and add it to the result.
+ * Similarly, to divide `a' by `b', we shift `b' left varying amounts,
+ * repeatedly trying to subtract it from `a'.  When we succeed, we note
+ * the fact by setting a bit in the quotient.  While these algorithms
+ * have the same O(n^2) time complexity as Knuth's, the ``constant factor''
+ * is likely to be larger.
+ *
+ * Because I used these algorithms, which require single-block addition
+ * and subtraction rather than single-block multiplication and division,
+ * the innermost loops of all four routines are very similar.  Study one
+ * of them and all will become clear.
+ */
+
+/*
+ * This is a little inline function used by both the multiplication
+ * routine and the division routine.
+ *
+ * `getShiftedBlock' returns the `x'th block of `num << y'.
+ * `y' may be anything from 0 to N - 1, and `x' may be anything from
+ * 0 to `num.len'.
+ *
+ * Two things contribute to this block:
+ *
+ * (1) The `N - y' low bits of `num.blk[x]', shifted `y' bits left.
+ *
+ * (2) The `y' high bits of `num.blk[x-1]', shifted `N - y' bits right.
+ *
+ * But we must be careful if `x == 0' or `x == num.len', in
+ * which case we should use 0 instead of (2) or (1), respectively.
+ *
+ * If `y == 0', then (2) contributes 0, as it should.  However,
+ * in some computer environments, for a reason I cannot understand,
+ * `a >> b' means `a >> (b % N)'.  This means `num.blk[x-1] >> (N - y)'
+ * will return `num.blk[x-1]' instead of the desired 0 when `y == 0';
+ * the test `y == 0' handles this case specially.
+ */
+inline BigUnsigned::Blk getShiftedBlock(const BigUnsigned &num,
+	BigUnsigned::Index x, unsigned int y) {
+	BigUnsigned::Blk part1 = (x == 0 || y == 0) ? 0 : (num.blk[x - 1] >> (BigUnsigned::N - y));
+	BigUnsigned::Blk part2 = (x == num.len) ? 0 : (num.blk[x] << y);
+	return part1 | part2;
+}
+
+void BigUnsigned::multiply(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, multiply(a, b));
+	// If either a or b is zero, set to zero.
+	if (a.len == 0 || b.len == 0) {
+		len = 0;
+		return;
+	}
+	/*
+	 * Overall method:
+	 *
+	 * Set this = 0.
+	 * For each 1-bit of `a' (say the `i2'th bit of block `i'):
+	 *    Add `b << (i blocks and i2 bits)' to *this.
+	 */
+	// Variables for the calculation
+	Index i, j, k;
+	unsigned int i2;
+	Blk temp;
+	bool carryIn, carryOut;
+	// Set preliminary length and make room
+	len = a.len + b.len;
+	allocate(len);
+	// Zero out this object
+	for (i = 0; i < len; i++)
+		blk[i] = 0;
+	// For each block of the first number...
+	for (i = 0; i < a.len; i++) {
+		// For each 1-bit of that block...
+		for (i2 = 0; i2 < N; i2++) {
+			if ((a.blk[i] & (Blk(1) << i2)) == 0)
+				continue;
+			/*
+			 * Add b to this, shifted left i blocks and i2 bits.
+			 * j is the index in b, and k = i + j is the index in this.
+			 *
+			 * `getShiftedBlock', a short inline function defined above,
+			 * is now used for the bit handling.  It replaces the more
+			 * complex `bHigh' code, in which each run of the loop dealt
+			 * immediately with the low bits and saved the high bits to
+			 * be picked up next time.  The last run of the loop used to
+			 * leave leftover high bits, which were handled separately.
+			 * Instead, this loop runs an additional time with j == b.len.
+			 * These changes were made on 2005.01.11.
+			 */
+			for (j = 0, k = i, carryIn = false; j <= b.len; j++, k++) {
+				/*
+				 * The body of this loop is very similar to the body of the first loop
+				 * in `add', except that this loop does a `+=' instead of a `+'.
+				 */
+				temp = blk[k] + getShiftedBlock(b, j, i2);
+				carryOut = (temp < blk[k]);
+				if (carryIn) {
+					temp++;
+					carryOut |= (temp == 0);
+				}
+				blk[k] = temp;
+				carryIn = carryOut;
+			}
+			// No more extra iteration to deal with `bHigh'.
+			// Roll-over a carry as necessary.
+			for (; carryIn; k++) {
+				blk[k]++;
+				carryIn = (blk[k] == 0);
+			}
+		}
+	}
+	// Zap possible leading zero
+	if (blk[len - 1] == 0)
+		len--;
+}
+
+/*
+ * DIVISION WITH REMAINDER
+ * This monstrous function mods *this by the given divisor b while storing the
+ * quotient in the given object q; at the end, *this contains the remainder.
+ * The seemingly bizarre pattern of inputs and outputs was chosen so that the
+ * function copies as little as possible (since it is implemented by repeated
+ * subtraction of multiples of b from *this).
+ * 
+ * "modWithQuotient" might be a better name for this function, but I would
+ * rather not change the name now.
+ */
+void BigUnsigned::divideWithRemainder(const BigUnsigned &b, BigUnsigned &q) {
+	/* Defending against aliased calls is more complex than usual because we
+	 * are writing to both *this and q.
+	 * 
+	 * It would be silly to try to write quotient and remainder to the
+	 * same variable.  Rule that out right away. */
+	if (this == &q)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned::divideWithRemainder: Cannot write quotient and remainder into the same variable";
+#endif
+	/* Now *this and q are separate, so the only concern is that b might be
+	 * aliased to one of them.  If so, use a temporary copy of b. */
+	if (this == &b || &q == &b) {
+		BigUnsigned tmpB(b);
+		divideWithRemainder(tmpB, q);
+		return;
+	}
+
+	/*
+	 * Knuth's definition of mod (which this function uses) is somewhat
+	 * different from the C++ definition of % in case of division by 0.
+	 *
+	 * We let a / 0 == 0 (it doesn't matter much) and a % 0 == a, no
+	 * exceptions thrown.  This allows us to preserve both Knuth's demand
+	 * that a mod 0 == a and the useful property that
+	 * (a / b) * b + (a % b) == a.
+	 */
+	if (b.len == 0) {
+		q.len = 0;
+		return;
+	}
+
+	/*
+	 * If *this.len < b.len, then *this < b, and we can be sure that b doesn't go into
+	 * *this at all.  The quotient is 0 and *this is already the remainder (so leave it alone).
+	 */
+	if (len < b.len) {
+		q.len = 0;
+		return;
+	}
+
+	// At this point we know (*this).len >= b.len > 0.  (Whew!)
+
+	/*
+	 * Overall method:
+	 *
+	 * For each appropriate i and i2, decreasing:
+	 *    Subtract (b << (i blocks and i2 bits)) from *this, storing the
+	 *      result in subtractBuf.
+	 *    If the subtraction succeeds with a nonnegative result:
+	 *        Turn on bit i2 of block i of the quotient q.
+	 *        Copy subtractBuf back into *this.
+	 *    Otherwise bit i2 of block i remains off, and *this is unchanged.
+	 * 
+	 * Eventually q will contain the entire quotient, and *this will
+	 * be left with the remainder.
+	 *
+	 * subtractBuf[x] corresponds to blk[x], not blk[x+i], since 2005.01.11.
+	 * But on a single iteration, we don't touch the i lowest blocks of blk
+	 * (and don't use those of subtractBuf) because these blocks are
+	 * unaffected by the subtraction: we are subtracting
+	 * (b << (i blocks and i2 bits)), which ends in at least `i' zero
+	 * blocks. */
+	// Variables for the calculation
+	Index i, j, k;
+	unsigned int i2;
+	Blk temp;
+	bool borrowIn, borrowOut;
+
+	/*
+	 * Make sure we have an extra zero block just past the value.
+	 *
+	 * When we attempt a subtraction, we might shift `b' so
+	 * its first block begins a few bits left of the dividend,
+	 * and then we'll try to compare these extra bits with
+	 * a nonexistent block to the left of the dividend.  The
+	 * extra zero block ensures sensible behavior; we need
+	 * an extra block in `subtractBuf' for exactly the same reason.
+	 */
+	Index origLen = len; // Save real length.
+	/* To avoid an out-of-bounds access in case of reallocation, allocate
+	 * first and then increment the logical length. */
+	allocateAndCopy(len + 1);
+	len++;
+	blk[origLen] = 0; // Zero the added block.
+
+	// subtractBuf holds part of the result of a subtraction; see above.
+	Blk *subtractBuf = new Blk[len];
+
+	// Set preliminary length for quotient and make room
+	q.len = origLen - b.len + 1;
+	q.allocate(q.len);
+	// Zero out the quotient
+	for (i = 0; i < q.len; i++)
+		q.blk[i] = 0;
+
+	// For each possible left-shift of b in blocks...
+	i = q.len;
+	while (i > 0) {
+		i--;
+		// For each possible left-shift of b in bits...
+		// (Remember, N is the number of bits in a Blk.)
+		q.blk[i] = 0;
+		i2 = N;
+		while (i2 > 0) {
+			i2--;
+			/*
+			 * Subtract b, shifted left i blocks and i2 bits, from *this,
+			 * and store the answer in subtractBuf.  In the for loop, `k == i + j'.
+			 *
+			 * Compare this to the middle section of `multiply'.  They
+			 * are in many ways analogous.  See especially the discussion
+			 * of `getShiftedBlock'.
+			 */
+			for (j = 0, k = i, borrowIn = false; j <= b.len; j++, k++) {
+				temp = blk[k] - getShiftedBlock(b, j, i2);
+				borrowOut = (temp > blk[k]);
+				if (borrowIn) {
+					borrowOut |= (temp == 0);
+					temp--;
+				}
+				// Since 2005.01.11, indices of `subtractBuf' directly match those of `blk', so use `k'.
+				subtractBuf[k] = temp; 
+				borrowIn = borrowOut;
+			}
+			// No more extra iteration to deal with `bHigh'.
+			// Roll-over a borrow as necessary.
+			for (; k < origLen && borrowIn; k++) {
+				borrowIn = (blk[k] == 0);
+				subtractBuf[k] = blk[k] - 1;
+			}
+			/*
+			 * If the subtraction was performed successfully (!borrowIn),
+			 * set bit i2 in block i of the quotient.
+			 *
+			 * Then, copy the portion of subtractBuf filled by the subtraction
+			 * back to *this.  This portion starts with block i and ends--
+			 * where?  Not necessarily at block `i + b.len'!  Well, we
+			 * increased k every time we saved a block into subtractBuf, so
+			 * the region of subtractBuf we copy is just [i, k).
+			 */
+			if (!borrowIn) {
+				q.blk[i] |= (Blk(1) << i2);
+				while (k > i) {
+					k--;
+					blk[k] = subtractBuf[k];
+				}
+			} 
+		}
+	}
+	// Zap possible leading zero in quotient
+	if (q.blk[q.len - 1] == 0)
+		q.len--;
+	// Zap any/all leading zeros in remainder
+	zapLeadingZeros();
+	// Deallocate subtractBuf.
+	// (Thanks to Brad Spencer for noticing my accidental omission of this!)
+	delete [] subtractBuf;
+}
+
+/* BITWISE OPERATORS
+ * These are straightforward blockwise operations except that they differ in
+ * the output length and the necessity of zapLeadingZeros. */
+
+void BigUnsigned::bitAnd(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, bitAnd(a, b));
+	// The bitwise & can't be longer than either operand.
+	len = (a.len >= b.len) ? b.len : a.len;
+	allocate(len);
+	Index i;
+	for (i = 0; i < len; i++)
+		blk[i] = a.blk[i] & b.blk[i];
+	zapLeadingZeros();
+}
+
+void BigUnsigned::bitOr(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, bitOr(a, b));
+	Index i;
+	const BigUnsigned *a2, *b2;
+	if (a.len >= b.len) {
+		a2 = &a;
+		b2 = &b;
+	} else {
+		a2 = &b;
+		b2 = &a;
+	}
+	allocate(a2->len);
+	for (i = 0; i < b2->len; i++)
+		blk[i] = a2->blk[i] | b2->blk[i];
+	for (; i < a2->len; i++)
+		blk[i] = a2->blk[i];
+	len = a2->len;
+	// Doesn't need zapLeadingZeros.
+}
+
+void BigUnsigned::bitXor(const BigUnsigned &a, const BigUnsigned &b) {
+	DTRT_ALIASED(this == &a || this == &b, bitXor(a, b));
+	Index i;
+	const BigUnsigned *a2, *b2;
+	if (a.len >= b.len) {
+		a2 = &a;
+		b2 = &b;
+	} else {
+		a2 = &b;
+		b2 = &a;
+	}
+	allocate(a2->len);
+	for (i = 0; i < b2->len; i++)
+		blk[i] = a2->blk[i] ^ b2->blk[i];
+	for (; i < a2->len; i++)
+		blk[i] = a2->blk[i];
+	len = a2->len;
+	zapLeadingZeros();
+}
+
+void BigUnsigned::bitShiftLeft(const BigUnsigned &a, int b) {
+	DTRT_ALIASED(this == &a, bitShiftLeft(a, b));
+	if (b < 0) {
+		if (b << 1 == 0)
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigUnsigned::bitShiftLeft: "
+				"Pathological shift amount not implemented";
+#endif
+		else {
+			bitShiftRight(a, -b);
+			return;
+		}
+	}
+	Index shiftBlocks = b / N;
+	unsigned int shiftBits = b % N;
+	// + 1: room for high bits nudged left into another block
+	len = a.len + shiftBlocks + 1;
+	allocate(len);
+	Index i, j;
+	for (i = 0; i < shiftBlocks; i++)
+		blk[i] = 0;
+	for (j = 0, i = shiftBlocks; j <= a.len; j++, i++)
+		blk[i] = getShiftedBlock(a, j, shiftBits);
+	// Zap possible leading zero
+	if (blk[len - 1] == 0)
+		len--;
+}
+
+void BigUnsigned::bitShiftRight(const BigUnsigned &a, int b) {
+	DTRT_ALIASED(this == &a, bitShiftRight(a, b));
+	if (b < 0) {
+		if (b << 1 == 0)
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigUnsigned::bitShiftRight: "
+				"Pathological shift amount not implemented";
+#endif
+		else {
+			bitShiftLeft(a, -b);
+			return;
+		}
+	}
+	// This calculation is wacky, but expressing the shift as a left bit shift
+	// within each block lets us use getShiftedBlock.
+	Index rightShiftBlocks = (b + N - 1) / N;
+	unsigned int leftShiftBits = N * rightShiftBlocks - b;
+	// Now (N * rightShiftBlocks - leftShiftBits) == b
+	// and 0 <= leftShiftBits < N.
+	if (rightShiftBlocks >= a.len + 1) {
+		// All of a is guaranteed to be shifted off, even considering the left
+		// bit shift.
+		len = 0;
+		return;
+	}
+	// Now we're allocating a positive amount.
+	// + 1: room for high bits nudged left into another block
+	len = a.len + 1 - rightShiftBlocks;
+	allocate(len);
+	Index i, j;
+	for (j = rightShiftBlocks, i = 0; j <= a.len; j++, i++)
+		blk[i] = getShiftedBlock(a, j, leftShiftBits);
+	// Zap possible leading zero
+	if (blk[len - 1] == 0)
+		len--;
+}
+
+// INCREMENT/DECREMENT OPERATORS
+
+// Prefix increment
+void BigUnsigned::operator ++() {
+	Index i;
+	bool carry = true;
+	for (i = 0; i < len && carry; i++) {
+		blk[i]++;
+		carry = (blk[i] == 0);
+	}
+	if (carry) {
+		// Allocate and then increase length, as in divideWithRemainder
+		allocateAndCopy(len + 1);
+		len++;
+		blk[i] = 1;
+	}
+}
+
+// Postfix increment: same as prefix
+void BigUnsigned::operator ++(int) {
+	operator ++();
+}
+
+// Prefix decrement
+void BigUnsigned::operator --() {
+	if (len == 0)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned::operator --(): Cannot decrement an unsigned zero";
+#endif
+	Index i;
+	bool borrow = true;
+	for (i = 0; borrow; i++) {
+		borrow = (blk[i] == 0);
+		blk[i]--;
+	}
+	// Zap possible leading zero (there can only be one)
+	if (blk[len - 1] == 0)
+		len--;
+}
+
+// Postfix decrement: same as prefix
+void BigUnsigned::operator --(int) {
+	operator --();
+}
diff --git a/third_party/bigint/BigUnsigned.hh b/third_party/bigint/BigUnsigned.hh
new file mode 100644
index 0000000000..accd4d6782
--- /dev/null
+++ b/third_party/bigint/BigUnsigned.hh
@@ -0,0 +1,456 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGUNSIGNED_H
+#define BIGUNSIGNED_H
+
+#include "NumberlikeArray.hh"
+
+/* A BigUnsigned object represents a nonnegative integer of size limited only by
+ * available memory.  BigUnsigneds support most mathematical operators and can
+ * be converted to and from most primitive integer types.
+ *
+ * The number is stored as a NumberlikeArray of unsigned longs as if it were
+ * written in base 256^sizeof(unsigned long).  The least significant block is
+ * first, and the length is such that the most significant block is nonzero. */
+class BigUnsigned : protected NumberlikeArray<unsigned long> {
+
+public:
+	// Enumeration for the result of a comparison.
+	enum CmpRes { less = -1, equal = 0, greater = 1 };
+
+	// BigUnsigneds are built with a Blk type of unsigned long.
+	typedef unsigned long Blk;
+
+	typedef NumberlikeArray<Blk>::Index Index;
+	using NumberlikeArray<Blk>::N;
+
+protected:
+	// Creates a BigUnsigned with a capacity; for internal use.
+	BigUnsigned(int, Index c) : NumberlikeArray<Blk>(0, c) {}
+
+	// Decreases len to eliminate any leading zero blocks.
+	void zapLeadingZeros() { 
+		while (len > 0 && blk[len - 1] == 0)
+			len--;
+	}
+
+public:
+	// Constructs zero.
+	BigUnsigned() : NumberlikeArray<Blk>() {}
+
+	// Copy constructor
+	BigUnsigned(const BigUnsigned &x) : NumberlikeArray<Blk>(x) {}
+
+	// Assignment operator
+	void operator=(const BigUnsigned &x) {
+		NumberlikeArray<Blk>::operator =(x);
+	}
+
+	// Constructor that copies from a given array of blocks.
+	BigUnsigned(const Blk *b, Index blen) : NumberlikeArray<Blk>(b, blen) {
+		// Eliminate any leading zeros we may have been passed.
+		zapLeadingZeros();
+	}
+
+	// Destructor.  NumberlikeArray does the delete for us.
+	~BigUnsigned() {}
+	
+	// Constructors from primitive integer types
+	BigUnsigned(unsigned long  x);
+	BigUnsigned(         long  x);
+	BigUnsigned(unsigned int   x);
+	BigUnsigned(         int   x);
+	BigUnsigned(unsigned short x);
+	BigUnsigned(         short x);
+protected:
+	// Helpers
+	template <class X> void initFromPrimitive      (X x);
+	template <class X> void initFromSignedPrimitive(X x);
+public:
+
+	/* Converters to primitive integer types
+	 * The implicit conversion operators caused trouble, so these are now
+	 * named. */
+	unsigned long  toUnsignedLong () const;
+	long           toLong         () const;
+	unsigned int   toUnsignedInt  () const;
+	int            toInt          () const;
+	unsigned short toUnsignedShort() const;
+	short          toShort        () const;
+protected:
+	// Helpers
+	template <class X> X convertToSignedPrimitive() const;
+	template <class X> X convertToPrimitive      () const;
+public:
+
+	// BIT/BLOCK ACCESSORS
+
+	// Expose these from NumberlikeArray directly.
+	using NumberlikeArray<Blk>::getCapacity;
+	using NumberlikeArray<Blk>::getLength;
+
+	/* Returns the requested block, or 0 if it is beyond the length (as if
+	 * the number had 0s infinitely to the left). */
+	Blk getBlock(Index i) const { return i >= len ? 0 : blk[i]; }
+	/* Sets the requested block.  The number grows or shrinks as necessary. */
+	void setBlock(Index i, Blk newBlock);
+
+	// The number is zero if and only if the canonical length is zero.
+	bool isZero() const { return NumberlikeArray<Blk>::isEmpty(); }
+
+	/* Returns the length of the number in bits, i.e., zero if the number
+	 * is zero and otherwise one more than the largest value of bi for
+	 * which getBit(bi) returns true. */
+	Index bitLength() const;
+	/* Get the state of bit bi, which has value 2^bi.  Bits beyond the
+	 * number's length are considered to be 0. */
+	bool getBit(Index bi) const {
+		return (getBlock(bi / N) & (Blk(1) << (bi % N))) != 0;
+	}
+	/* Sets the state of bit bi to newBit.  The number grows or shrinks as
+	 * necessary. */
+	void setBit(Index bi, bool newBit);
+
+	// COMPARISONS
+
+	// Compares this to x like Perl's <=>
+	CmpRes compareTo(const BigUnsigned &x) const;
+
+	// Ordinary comparison operators
+	bool operator ==(const BigUnsigned &x) const {
+		return NumberlikeArray<Blk>::operator ==(x);
+	}
+	bool operator !=(const BigUnsigned &x) const {
+		return NumberlikeArray<Blk>::operator !=(x);
+	}
+	bool operator < (const BigUnsigned &x) const { return compareTo(x) == less   ; }
+	bool operator <=(const BigUnsigned &x) const { return compareTo(x) != greater; }
+	bool operator >=(const BigUnsigned &x) const { return compareTo(x) != less   ; }
+	bool operator > (const BigUnsigned &x) const { return compareTo(x) == greater; }
+
+	/*
+	 * BigUnsigned and BigInteger both provide three kinds of operators.
+	 * Here ``big-integer'' refers to BigInteger or BigUnsigned.
+	 *
+	 * (1) Overloaded ``return-by-value'' operators:
+	 *     +, -, *, /, %, unary -, &, |, ^, <<, >>.
+	 * Big-integer code using these operators looks identical to code using
+	 * the primitive integer types.  These operators take one or two
+	 * big-integer inputs and return a big-integer result, which can then
+	 * be assigned to a BigInteger variable or used in an expression.
+	 * Example:
+	 *     BigInteger a(1), b = 1;
+	 *     BigInteger c = a + b;
+	 *
+	 * (2) Overloaded assignment operators:
+	 *     +=, -=, *=, /=, %=, flipSign, &=, |=, ^=, <<=, >>=, ++, --.
+	 * Again, these are used on big integers just like on ints.  They take
+	 * one writable big integer that both provides an operand and receives a
+	 * result.  Most also take a second read-only operand.
+	 * Example:
+	 *     BigInteger a(1), b(1);
+	 *     a += b;
+	 *
+	 * (3) Copy-less operations: `add', `subtract', etc.
+	 * These named methods take operands as arguments and store the result
+	 * in the receiver (*this), avoiding unnecessary copies and allocations.
+	 * `divideWithRemainder' is special: it both takes the dividend from and
+	 * stores the remainder into the receiver, and it takes a separate
+	 * object in which to store the quotient.  NOTE: If you are wondering
+	 * why these don't return a value, you probably mean to use the
+	 * overloaded return-by-value operators instead.
+	 * 
+	 * Examples:
+	 *     BigInteger a(43), b(7), c, d;
+	 *
+	 *     c = a + b;   // Now c == 50.
+	 *     c.add(a, b); // Same effect but without the two copies.
+	 *
+	 *     c.divideWithRemainder(b, d);
+	 *     // 50 / 7; now d == 7 (quotient) and c == 1 (remainder).
+	 *
+	 *     // ``Aliased'' calls now do the right thing using a temporary
+	 *     // copy, but see note on `divideWithRemainder'.
+	 *     a.add(a, b); 
+	 */
+
+	// COPY-LESS OPERATIONS
+
+	// These 8: Arguments are read-only operands, result is saved in *this.
+	void add(const BigUnsigned &a, const BigUnsigned &b);
+	void subtract(const BigUnsigned &a, const BigUnsigned &b);
+	void multiply(const BigUnsigned &a, const BigUnsigned &b);
+	void bitAnd(const BigUnsigned &a, const BigUnsigned &b);
+	void bitOr(const BigUnsigned &a, const BigUnsigned &b);
+	void bitXor(const BigUnsigned &a, const BigUnsigned &b);
+	/* Negative shift amounts translate to opposite-direction shifts,
+	 * except for -2^(8*sizeof(int)-1) which is unimplemented. */
+	void bitShiftLeft(const BigUnsigned &a, int b);
+	void bitShiftRight(const BigUnsigned &a, int b);
+
+	/* `a.divideWithRemainder(b, q)' is like `q = a / b, a %= b'.
+	 * / and % use semantics similar to Knuth's, which differ from the
+	 * primitive integer semantics under division by zero.  See the
+	 * implementation in BigUnsigned.cc for details.
+	 * `a.divideWithRemainder(b, a)' throws an exception: it doesn't make
+	 * sense to write quotient and remainder into the same variable. */
+	void divideWithRemainder(const BigUnsigned &b, BigUnsigned &q);
+
+	/* `divide' and `modulo' are no longer offered.  Use
+	 * `divideWithRemainder' instead. */
+
+	// OVERLOADED RETURN-BY-VALUE OPERATORS
+	BigUnsigned operator +(const BigUnsigned &x) const;
+	BigUnsigned operator -(const BigUnsigned &x) const;
+	BigUnsigned operator *(const BigUnsigned &x) const;
+	BigUnsigned operator /(const BigUnsigned &x) const;
+	BigUnsigned operator %(const BigUnsigned &x) const;
+	/* OK, maybe unary minus could succeed in one case, but it really
+	 * shouldn't be used, so it isn't provided. */
+	BigUnsigned operator &(const BigUnsigned &x) const;
+	BigUnsigned operator |(const BigUnsigned &x) const;
+	BigUnsigned operator ^(const BigUnsigned &x) const;
+	BigUnsigned operator <<(int b) const;
+	BigUnsigned operator >>(int b) const;
+
+	// OVERLOADED ASSIGNMENT OPERATORS
+	void operator +=(const BigUnsigned &x);
+	void operator -=(const BigUnsigned &x);
+	void operator *=(const BigUnsigned &x);
+	void operator /=(const BigUnsigned &x);
+	void operator %=(const BigUnsigned &x);
+	void operator &=(const BigUnsigned &x);
+	void operator |=(const BigUnsigned &x);
+	void operator ^=(const BigUnsigned &x);
+	void operator <<=(int b);
+	void operator >>=(int b);
+
+	/* INCREMENT/DECREMENT OPERATORS
+	 * To discourage messy coding, these do not return *this, so prefix
+	 * and postfix behave the same. */
+	void operator ++(   );
+	void operator ++(int);
+	void operator --(   );
+	void operator --(int);
+
+	// Helper function that needs access to BigUnsigned internals
+	friend Blk getShiftedBlock(const BigUnsigned &num, Index x,
+			unsigned int y);
+
+	// See BigInteger.cc.
+	template <class X>
+	friend X convertBigUnsignedToPrimitiveAccess(const BigUnsigned &a);
+};
+
+/* Implementing the return-by-value and assignment operators in terms of the
+ * copy-less operations.  The copy-less operations are responsible for making
+ * any necessary temporary copies to work around aliasing. */
+
+inline BigUnsigned BigUnsigned::operator +(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.add(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator -(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.subtract(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator *(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.multiply(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator /(const BigUnsigned &x) const {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigUnsigned::operator /: division by zero";
+#endif
+	BigUnsigned q, r;
+	r = *this;
+	r.divideWithRemainder(x, q);
+	return q;
+}
+inline BigUnsigned BigUnsigned::operator %(const BigUnsigned &x) const {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigUnsigned::operator %: division by zero";
+#endif
+	BigUnsigned q, r;
+	r = *this;
+	r.divideWithRemainder(x, q);
+	return r;
+}
+inline BigUnsigned BigUnsigned::operator &(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.bitAnd(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator |(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.bitOr(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator ^(const BigUnsigned &x) const {
+	BigUnsigned ans;
+	ans.bitXor(*this, x);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator <<(int b) const {
+	BigUnsigned ans;
+	ans.bitShiftLeft(*this, b);
+	return ans;
+}
+inline BigUnsigned BigUnsigned::operator >>(int b) const {
+	BigUnsigned ans;
+	ans.bitShiftRight(*this, b);
+	return ans;
+}
+
+inline void BigUnsigned::operator +=(const BigUnsigned &x) {
+	add(*this, x);
+}
+inline void BigUnsigned::operator -=(const BigUnsigned &x) {
+	subtract(*this, x);
+}
+inline void BigUnsigned::operator *=(const BigUnsigned &x) {
+	multiply(*this, x);
+}
+inline void BigUnsigned::operator /=(const BigUnsigned &x) {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigUnsigned::operator /=: division by zero";
+#endif
+	/* The following technique is slightly faster than copying *this first
+	 * when x is large. */
+	BigUnsigned q;
+	divideWithRemainder(x, q);
+	// *this contains the remainder, but we overwrite it with the quotient.
+	*this = q;
+}
+inline void BigUnsigned::operator %=(const BigUnsigned &x) {
+	if (x.isZero())
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+        throw "BigUnsigned::operator %=: division by zero";
+#endif
+	BigUnsigned q;
+	// Mods *this by x.  Don't care about quotient left in q.
+	divideWithRemainder(x, q);
+}
+inline void BigUnsigned::operator &=(const BigUnsigned &x) {
+	bitAnd(*this, x);
+}
+inline void BigUnsigned::operator |=(const BigUnsigned &x) {
+	bitOr(*this, x);
+}
+inline void BigUnsigned::operator ^=(const BigUnsigned &x) {
+	bitXor(*this, x);
+}
+inline void BigUnsigned::operator <<=(int b) {
+	bitShiftLeft(*this, b);
+}
+inline void BigUnsigned::operator >>=(int b) {
+	bitShiftRight(*this, b);
+}
+
+/* Templates for conversions of BigUnsigned to and from primitive integers.
+ * BigInteger.cc needs to instantiate convertToPrimitive, and the uses in
+ * BigUnsigned.cc didn't do the trick; I think g++ inlined convertToPrimitive
+ * instead of generating linkable instantiations.  So for consistency, I put
+ * all the templates here. */
+
+// CONSTRUCTION FROM PRIMITIVE INTEGERS
+
+/* Initialize this BigUnsigned from the given primitive integer.  The same
+ * pattern works for all primitive integer types, so I put it into a template to
+ * reduce code duplication.  (Don't worry: this is protected and we instantiate
+ * it only with primitive integer types.)  Type X could be signed, but x is
+ * known to be nonnegative. */
+template <class X>
+void BigUnsigned::initFromPrimitive(X x) {
+	if (x == 0)
+		; // NumberlikeArray already initialized us to zero.
+	else {
+		// Create a single block.  blk is NULL; no need to delete it.
+		cap = 1;
+		blk = new Blk[1];
+		len = 1;
+		blk[0] = Blk(x);
+	}
+}
+
+/* Ditto, but first check that x is nonnegative.  I could have put the check in
+ * initFromPrimitive and let the compiler optimize it out for unsigned-type
+ * instantiations, but I wanted to avoid the warning stupidly issued by g++ for
+ * a condition that is constant in *any* instantiation, even if not in all. */
+template <class X>
+void BigUnsigned::initFromSignedPrimitive(X x) {
+	if (x < 0)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned constructor: "
+			"Cannot construct a BigUnsigned from a negative number";
+#endif
+	else
+		initFromPrimitive(x);
+}
+
+// CONVERSION TO PRIMITIVE INTEGERS
+
+/* Template with the same idea as initFromPrimitive.  This might be slightly
+ * slower than the previous version with the masks, but it's much shorter and
+ * clearer, which is the library's stated goal. */
+template <class X>
+X BigUnsigned::convertToPrimitive() const {
+	if (len == 0)
+		// The number is zero; return zero.
+		return 0;
+	else if (len == 1) {
+		// The single block might fit in an X.  Try the conversion.
+		X x = X(blk[0]);
+		// Make sure the result accurately represents the block.
+		if (Blk(x) == blk[0])
+			// Successful conversion.
+			return x;
+		// Otherwise fall through.
+	}
+#ifdef FOXIT_CHROME_BUILD
+    abort();
+#else
+	throw "BigUnsigned::to<Primitive>: "
+		"Value is too big to fit in the requested type";
+#endif
+}
+
+/* Wrap the above in an x >= 0 test to make sure we got a nonnegative result,
+ * not a negative one that happened to convert back into the correct nonnegative
+ * one.  (E.g., catch incorrect conversion of 2^31 to the long -2^31.)  Again,
+ * separated to avoid a g++ warning. */
+template <class X>
+X BigUnsigned::convertToSignedPrimitive() const {
+	X x = convertToPrimitive<X>();
+	if (x >= 0)
+		return x;
+	else
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsigned::to(Primitive): "
+			"Value is too big to fit in the requested type";
+#endif
+}
+
+#endif
diff --git a/third_party/bigint/BigUnsignedInABase.cc b/third_party/bigint/BigUnsignedInABase.cc
new file mode 100644
index 0000000000..a24042d538
--- /dev/null
+++ b/third_party/bigint/BigUnsignedInABase.cc
@@ -0,0 +1,159 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#include "BigUnsignedInABase.hh"
+
+BigUnsignedInABase::BigUnsignedInABase(const Digit *d, Index l, Base base)
+	: NumberlikeArray<Digit>(d, l), base(base) {
+	// Check the base
+	if (base < 2)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): The base must be at least 2";
+#endif
+
+	// Validate the digits.
+	for (Index i = 0; i < l; i++)
+		if (blk[i] >= base)
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+#endif
+
+	// Eliminate any leading zeros we may have been passed.
+	zapLeadingZeros();
+}
+
+namespace {
+	unsigned int bitLen(unsigned int x) {
+		unsigned int len = 0;
+		while (x > 0) {
+			x >>= 1;
+			len++;
+		}
+		return len;
+	}
+	unsigned int ceilingDiv(unsigned int a, unsigned int b) {
+		return (a + b - 1) / b;
+	}
+}
+
+BigUnsignedInABase::BigUnsignedInABase(const BigUnsigned &x, Base base) {
+	// Check the base
+	if (base < 2)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsignedInABase(BigUnsigned, Base): The base must be at least 2";
+#endif
+	this->base = base;
+
+	// Get an upper bound on how much space we need
+	int maxBitLenOfX = x.getLength() * BigUnsigned::N;
+	int minBitsPerDigit = bitLen(base) - 1;
+	int maxDigitLenOfX = ceilingDiv(maxBitLenOfX, minBitsPerDigit);
+	len = maxDigitLenOfX; // Another change to comply with `staying in bounds'.
+	allocate(len); // Get the space
+
+	BigUnsigned x2(x), buBase(base);
+	Index digitNum = 0;
+
+	while (!x2.isZero()) {
+		// Get last digit.  This is like `lastDigit = x2 % buBase, x2 /= buBase'.
+		BigUnsigned lastDigit(x2);
+		lastDigit.divideWithRemainder(buBase, x2);
+		// Save the digit.
+		blk[digitNum] = lastDigit.toUnsignedShort();
+		// Move on.  We can't run out of room: we figured it out above.
+		digitNum++;
+	}
+
+	// Save the actual length.
+	len = digitNum;
+}
+
+BigUnsignedInABase::operator BigUnsigned() const {
+	BigUnsigned ans(0), buBase(base), temp;
+	Index digitNum = len;
+	while (digitNum > 0) {
+		digitNum--;
+		temp.multiply(ans, buBase);
+		ans.add(temp, BigUnsigned(blk[digitNum]));
+	}
+	return ans;
+}
+
+BigUnsignedInABase::BigUnsignedInABase(const std::string &s, Base base) {
+	// Check the base.
+	if (base > 36)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsignedInABase(std::string, Base): The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36.  You tried a conversion with a base over 36; write your own string conversion routine.";
+#endif
+	// Save the base.
+	// This pattern is seldom seen in C++, but the analogous ``this.'' is common in Java.
+	this->base = base;
+
+	// `s.length()' is a `size_t', while `len' is a `NumberlikeArray::Index',
+	// also known as an `unsigned int'.  Some compilers warn without this cast.
+	len = Index(s.length());
+	allocate(len);
+
+	Index digitNum, symbolNumInString;
+	for (digitNum = 0; digitNum < len; digitNum++) {
+		symbolNumInString = len - 1 - digitNum;
+		char theSymbol = s[symbolNumInString];
+		if (theSymbol >= '0' && theSymbol <= '9')
+			blk[digitNum] = theSymbol - '0';
+		else if (theSymbol >= 'A' && theSymbol <= 'Z')
+			blk[digitNum] = theSymbol - 'A' + 10;
+		else if (theSymbol >= 'a' && theSymbol <= 'z')
+			blk[digitNum] = theSymbol - 'a' + 10;
+		else
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigUnsignedInABase(std::string, Base): Bad symbol in input.  Only 0-9, A-Z, a-z are accepted.";
+#endif
+
+		if (blk[digitNum] >= base)
+#ifdef FOXIT_CHROME_BUILD
+            abort();
+#else
+			throw "BigUnsignedInABase::BigUnsignedInABase(const Digit *, Index, Base): A digit is too large for the specified base";
+#endif
+	}
+	zapLeadingZeros();
+}
+
+BigUnsignedInABase::operator std::string() const {
+	if (base > 36)
+#ifdef FOXIT_CHROME_BUILD
+        abort();
+#else
+		throw "BigUnsignedInABase ==> std::string: The default string conversion routines use the symbol set 0-9, A-Z and therefore support only up to base 36.  You tried a conversion with a base over 36; write your own string conversion routine.";
+#endif
+	if (len == 0)
+		return std::string("0");
+	// Some compilers don't have push_back, so use a char * buffer instead.
+	char *s = new char[len + 1];
+	s[len] = '\0';
+	Index digitNum, symbolNumInString;
+	for (symbolNumInString = 0; symbolNumInString < len; symbolNumInString++) {
+		digitNum = len - 1 - symbolNumInString;
+		Digit theDigit = blk[digitNum];
+		if (theDigit < 10)
+			s[symbolNumInString] = char('0' + theDigit);
+		else
+			s[symbolNumInString] = char('A' + theDigit - 10);
+	}
+	std::string s2(s);
+	delete [] s;
+	return s2;
+}
diff --git a/third_party/bigint/BigUnsignedInABase.hh b/third_party/bigint/BigUnsignedInABase.hh
new file mode 100644
index 0000000000..dbd2cf904c
--- /dev/null
+++ b/third_party/bigint/BigUnsignedInABase.hh
@@ -0,0 +1,128 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef BIGUNSIGNEDINABASE_H
+#define BIGUNSIGNEDINABASE_H
+
+#include "NumberlikeArray.hh"
+#include "BigUnsigned.hh"
+#include <string>
+
+/*
+ * A BigUnsignedInABase object represents a nonnegative integer of size limited
+ * only by available memory, represented in a user-specified base that can fit
+ * in an `unsigned short' (most can, and this saves memory).
+ *
+ * BigUnsignedInABase is intended as an intermediary class with little
+ * functionality of its own.  BigUnsignedInABase objects can be constructed
+ * from, and converted to, BigUnsigneds (requiring multiplication, mods, etc.)
+ * and `std::string's (by switching digit values for appropriate characters).
+ *
+ * BigUnsignedInABase is similar to BigUnsigned.  Note the following:
+ *
+ * (1) They represent the number in exactly the same way, except that
+ * BigUnsignedInABase uses ``digits'' (or Digit) where BigUnsigned uses
+ * ``blocks'' (or Blk).
+ *
+ * (2) Both use the management features of NumberlikeArray.  (In fact, my desire
+ * to add a BigUnsignedInABase class without duplicating a lot of code led me to
+ * introduce NumberlikeArray.)
+ *
+ * (3) The only arithmetic operation supported by BigUnsignedInABase is an
+ * equality test.  Use BigUnsigned for arithmetic.
+ */
+
+class BigUnsignedInABase : protected NumberlikeArray<unsigned short> {
+
+public:
+	// The digits of a BigUnsignedInABase are unsigned shorts.
+	typedef unsigned short Digit;
+	// That's also the type of a base.
+	typedef Digit Base;
+
+protected:
+	// The base in which this BigUnsignedInABase is expressed
+	Base base;
+
+	// Creates a BigUnsignedInABase with a capacity; for internal use.
+	BigUnsignedInABase(int, Index c) : NumberlikeArray<Digit>(0, c) {}
+
+	// Decreases len to eliminate any leading zero digits.
+	void zapLeadingZeros() { 
+		while (len > 0 && blk[len - 1] == 0)
+			len--;
+	}
+
+public:
+	// Constructs zero in base 2.
+	BigUnsignedInABase() : NumberlikeArray<Digit>(), base(2) {}
+
+	// Copy constructor
+	BigUnsignedInABase(const BigUnsignedInABase &x) : NumberlikeArray<Digit>(x), base(x.base) {}
+
+	// Assignment operator
+	void operator =(const BigUnsignedInABase &x) {
+		NumberlikeArray<Digit>::operator =(x);
+		base = x.base;
+	}
+
+	// Constructor that copies from a given array of digits.
+	BigUnsignedInABase(const Digit *d, Index l, Base base);
+
+	// Destructor.  NumberlikeArray does the delete for us.
+	~BigUnsignedInABase() {}
+
+	// LINKS TO BIGUNSIGNED
+	BigUnsignedInABase(const BigUnsigned &x, Base base);
+	operator BigUnsigned() const;
+
+	/* LINKS TO STRINGS
+	 *
+	 * These use the symbols ``0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'' to
+	 * represent digits of 0 through 35.  When parsing strings, lowercase is
+	 * also accepted.
+	 *
+	 * All string representations are big-endian (big-place-value digits
+	 * first).  (Computer scientists have adopted zero-based counting; why
+	 * can't they tolerate little-endian numbers?)
+	 *
+	 * No string representation has a ``base indicator'' like ``0x''.
+	 *
+	 * An exception is made for zero: it is converted to ``0'' and not the
+	 * empty string.
+	 *
+	 * If you want different conventions, write your own routines to go
+	 * between BigUnsignedInABase and strings.  It's not hard.
+	 */
+	operator std::string() const;
+	BigUnsignedInABase(const std::string &s, Base base);
+
+public:
+
+	// ACCESSORS
+	Base getBase() const { return base; }
+
+	// Expose these from NumberlikeArray directly.
+	using NumberlikeArray<Digit>::getCapacity;
+	using NumberlikeArray<Digit>::getLength;
+
+	/* Returns the requested digit, or 0 if it is beyond the length (as if
+	 * the number had 0s infinitely to the left). */
+	Digit getDigit(Index i) const { return i >= len ? 0 : blk[i]; }
+
+	// The number is zero if and only if the canonical length is zero.
+	bool isZero() const { return NumberlikeArray<Digit>::isEmpty(); }
+
+	/* Equality test.  For the purposes of this test, two BigUnsignedInABase
+	 * values must have the same base to be equal. */ 
+	bool operator ==(const BigUnsignedInABase &x) const {
+		return base == x.base && NumberlikeArray<Digit>::operator ==(x);
+	}
+	bool operator !=(const BigUnsignedInABase &x) const { return !operator ==(x); }
+
+};
+
+#endif
diff --git a/third_party/bigint/LICENSE b/third_party/bigint/LICENSE
new file mode 100644
index 0000000000..ae9d3dac5f
--- /dev/null
+++ b/third_party/bigint/LICENSE
@@ -0,0 +1,71 @@
+
+                            C++ Big Integer Library
+                          (see ChangeLog for version)
+
+                        http://mattmccutchen.net/bigint/
+
+       Written and maintained by Matt McCutchen <matt@mattmccutchen.net>
+
+You can use this library in a C++ program to do arithmetic on integers of size
+limited only by your computer's memory.  The library provides BigUnsigned and
+BigInteger classes that represent nonnegative integers and signed integers,
+respectively.  Most of the C++ arithmetic operators are overloaded for these
+classes, so big-integer calculations are as easy as:
+
+    #include "BigIntegerLibrary.hh"
+    
+    BigInteger a = 65536;
+    cout << (a * a * a * a * a * a * a * a);
+    
+    (prints 340282366920938463463374607431768211456)
+
+The code in `sample.cc' demonstrates the most important features of the library.
+To get started quickly, read the code and explanations in that file and run it.
+If you want more detail or a feature not shown in `sample.cc', consult the
+consult the actual header and source files, which are thoroughly commented.
+
+This library emphasizes ease of use and clarity of implementation over speed;
+some users will prefer GMP (http://swox.com/gmp/), which is faster.  The code is
+intended to be reasonably portable across computers and modern C++ compilers; in
+particular, it uses whatever word size the computer provides (32-bit, 64-bit, or
+otherwise).
+
+Compiling programs that use the library
+---------------------------------------
+The library consists of a folder full of C++ header files (`.hh') and source
+files (`.cc').  Your own programs should `#include' the necessary header files
+and link with the source files.  A makefile that builds the sample program
+(`sample.cc') is included; you can adapt it to replace the sample with your own
+program.
+
+Alternatively, you can use your own build system or IDE.  In that case, you must
+put the library header files where the compiler will find them and arrange to
+have your program linked with the library source files; otherwise, you will get
+errors about missing header files or "undefined references".  To learn how to do
+this, consult the documentation for the build system or IDE; don't bother asking
+me.  Adding all the library files to your project will work in many IDEs but may
+not be the most desirable approach.
+
+Resources
+---------
+The library's Web site (above) provides links to released versions, the current
+development version, and a mailing list for release announcements, questions,
+bug reports, and other discussion of the library.  I would be delighted to hear
+from you if you like this library and/or find a good use for it.
+
+Bugs and enhancements
+---------------------
+The library has been tested by me and others but is by no means bug-free.  If
+you find a bug, please report it, whether it comes in the form of compiling
+trouble, a mathematically inaccurate result, or a memory-management blooper
+(since I use Java, these are altogether too common in my C++).  I generally fix
+all reported bugs.  You are also welcome to request enhancements, but I am
+unlikely to do substantial amounts of work on enhancements at this point.
+
+Legal
+-----
+I, Matt McCutchen, the sole author of the original Big Integer Library, waive my
+copyright to it, placing it in the public domain.  The library comes with
+absolutely no warranty.
+
+~~~~
diff --git a/third_party/bigint/NumberlikeArray.hh b/third_party/bigint/NumberlikeArray.hh
new file mode 100644
index 0000000000..f7917809f4
--- /dev/null
+++ b/third_party/bigint/NumberlikeArray.hh
@@ -0,0 +1,184 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code by Matt McCutchen, see the LICENSE file.
+
+#ifndef NUMBERLIKEARRAY_H
+#define NUMBERLIKEARRAY_H
+
+#include <stdlib.h> // abort()
+// Make sure we have NULL.
+#ifndef NULL
+#define NULL 0
+#endif
+
+/* A NumberlikeArray<Blk> object holds a heap-allocated array of Blk with a
+ * length and a capacity and provides basic memory management features.
+ * BigUnsigned and BigUnsignedInABase both subclass it.
+ *
+ * NumberlikeArray provides no information hiding.  Subclasses should use
+ * nonpublic inheritance and manually expose members as desired using
+ * declarations like this:
+ *
+ * public:
+ *     NumberlikeArray< the-type-argument >::getLength;
+ */
+template <class Blk>
+class NumberlikeArray {
+public:
+
+	// Type for the index of a block in the array
+	typedef unsigned int Index;
+	// The number of bits in a block, defined below.
+	static const unsigned int N;
+
+	// The current allocated capacity of this NumberlikeArray (in blocks)
+	Index cap;
+	// The actual length of the value stored in this NumberlikeArray (in blocks)
+	Index len;
+	// Heap-allocated array of the blocks (can be NULL if len == 0)
+	Blk *blk;
+
+	// Constructs a ``zero'' NumberlikeArray with the given capacity.
+	NumberlikeArray(Index c) : cap(c), len(0) { 
+		blk = (cap > 0) ? (new Blk[cap]) : NULL;
+	}
+
+	/* Constructs a zero NumberlikeArray without allocating a backing array.
+	 * A subclass that doesn't know the needed capacity at initialization
+	 * time can use this constructor and then overwrite blk without first
+	 * deleting it. */
+	NumberlikeArray() : cap(0), len(0) {
+		blk = NULL;
+	}
+
+	// Destructor.  Note that `delete NULL' is a no-op.
+	~NumberlikeArray() {
+		delete [] blk;
+	}
+
+	/* Ensures that the array has at least the requested capacity; may
+	 * destroy the contents. */
+	void allocate(Index c);
+
+	/* Ensures that the array has at least the requested capacity; does not
+	 * destroy the contents. */
+	void allocateAndCopy(Index c);
+
+	// Copy constructor
+	NumberlikeArray(const NumberlikeArray<Blk> &x);
+
+	// Assignment operator
+	void operator=(const NumberlikeArray<Blk> &x);
+
+	// Constructor that copies from a given array of blocks
+	NumberlikeArray(const Blk *b, Index blen);
+
+	// ACCESSORS
+	Index getCapacity()     const { return cap;      }
+	Index getLength()       const { return len;      }
+	Blk   getBlock(Index i) const { return blk[i];   }
+	bool  isEmpty()         const { return len == 0; }
+
+	/* Equality comparison: checks if both objects have the same length and
+	 * equal (==) array elements to that length.  Subclasses may wish to
+	 * override. */
+	bool operator ==(const NumberlikeArray<Blk> &x) const;
+
+	bool operator !=(const NumberlikeArray<Blk> &x) const {
+		return !operator ==(x);
+	}
+};
+
+/* BEGIN TEMPLATE DEFINITIONS.  They are present here so that source files that
+ * include this header file can generate the necessary real definitions. */
+
+template <class Blk>
+const unsigned int NumberlikeArray<Blk>::N = 8 * sizeof(Blk);
+
+template <class Blk>
+void NumberlikeArray<Blk>::allocate(Index c) {
+	// If the requested capacity is more than the current capacity...
+	if (c > cap) {
+		// Delete the old number array
+		delete [] blk;
+		// Allocate the new array
+		cap = c;
+		blk = new Blk[cap];
+	}
+}
+
+template <class Blk>
+void NumberlikeArray<Blk>::allocateAndCopy(Index c) {
+	// If the requested capacity is more than the current capacity...
+	if (c > cap) {
+		Blk *oldBlk = blk;
+		// Allocate the new number array
+		cap = c;
+		blk = new Blk[cap];
+		// Copy number blocks
+		Index i;
+		for (i = 0; i < len; i++)
+			blk[i] = oldBlk[i];
+		// Delete the old array
+		delete [] oldBlk;
+	}
+}
+
+template <class Blk>
+NumberlikeArray<Blk>::NumberlikeArray(const NumberlikeArray<Blk> &x)
+		: len(x.len) {
+	// Create array
+	cap = len;
+	blk = new Blk[cap];
+	// Copy blocks
+	Index i;
+	for (i = 0; i < len; i++)
+		blk[i] = x.blk[i];
+}
+
+template <class Blk>
+void NumberlikeArray<Blk>::operator=(const NumberlikeArray<Blk> &x) {
+	/* Calls like a = a have no effect; catch them before the aliasing
+	 * causes a problem */
+	if (this == &x)
+		return;
+	// Copy length
+	len = x.len;
+	// Expand array if necessary
+	allocate(len);
+	// Copy number blocks
+	Index i;
+	for (i = 0; i < len; i++)
+		blk[i] = x.blk[i];
+}
+
+template <class Blk>
+NumberlikeArray<Blk>::NumberlikeArray(const Blk *b, Index blen)
+		: cap(blen), len(blen) {
+	// Create array
+	blk = new Blk[cap];
+	// Copy blocks
+	Index i;
+	for (i = 0; i < len; i++)
+		blk[i] = b[i];
+}
+
+template <class Blk>
+bool NumberlikeArray<Blk>::operator ==(const NumberlikeArray<Blk> &x) const {
+	if (len != x.len)
+		// Definitely unequal.
+		return false;
+	else {
+		// Compare corresponding blocks one by one.
+		Index i;
+		for (i = 0; i < len; i++)
+			if (blk[i] != x.blk[i])
+				return false;
+		// No blocks differed, so the objects are equal.
+		return true;
+	}
+}
+
+#endif