From caea6f1c593ec93abe38339c3757e637f546c616 Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Tue, 5 Apr 2016 14:22:45 -0400
Subject: [PATCH] Updated documentation

---
 algebra.h  | 190 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 modarith.h |  54 ++++++++-------
 pwdbased.h |   1 +
 3 files changed, 207 insertions(+), 38 deletions(-)

diff --git a/algebra.h b/algebra.h
index 647a4d61..1559cb47 100644
--- a/algebra.h
+++ b/algebra.h
@@ -1,7 +1,6 @@
 // algebra.h - written and placed in the public domain by Wei Dai
 
-//! \file
-//! \headerfile algebra.h
+//! \file algebra.h
 //! \brief Classes for performing mathematics over different fields
 
 #ifndef CRYPTOPP_ALGEBRA_H
@@ -15,15 +14,15 @@ NAMESPACE_BEGIN(CryptoPP)
 
 class Integer;
 
-// "const Element&" returned by member functions are references
-// to internal data members. Since each object may have only
-// one such data member for holding results, the following code
-// will produce incorrect results:
-// abcd = group.Add(group.Add(a,b), group.Add(c,d));
-// But this should be fine:
-// abcd = group.Add(a, group.Add(b, group.Add(c,d));
-
-//! Abstract Group
+//! \brief Abstract group
+//! \tparam T element class or type
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 template <class T> class CRYPTOPP_NO_VTABLE AbstractGroup
 {
 public:
@@ -31,48 +30,167 @@ public:
 
 	virtual ~AbstractGroup() {}
 
+	//! \brief Compare two elements for equality
+	//! \param a first element
+	//! \param b second element
+	//! \returns true if the elements are equal, false otherwise
+	//! \details Equal() tests the elements for equality using <tt>a==b</tt>
 	virtual bool Equal(const Element &a, const Element &b) const =0;
+
+	//! \brief Provides the Identity element
+	//! \returns the Identity element
 	virtual const Element& Identity() const =0;
+
+	//! \brief Adds elements in the group
+	//! \param a first element
+	//! \param b second element
+	//! \returns the sum of <tt>a</tt> and <tt>b</tt>
 	virtual const Element& Add(const Element &a, const Element &b) const =0;
+
+	//! \brief Inverts the element in the group
+	//! \param a first element
+	//! \returns the inverse of the element
 	virtual const Element& Inverse(const Element &a) const =0;
+
+	//! \brief Determine if inversion is fast
+	//! \returns true if inversion is fast, false otherwise
 	virtual bool InversionIsFast() const {return false;}
 
+	//! \brief Doubles an element in the group
+	//! \param a the element
+	//! \returns the element doubled
 	virtual const Element& Double(const Element &a) const;
+
+	//! \brief Subtracts elements in the group
+	//! \param a first element
+	//! \param b second element
+	//! \returns the difference of <tt>a</tt> and <tt>b</tt>. The element <tt>a</tt> must provide a Subtract member function.
 	virtual const Element& Subtract(const Element &a, const Element &b) const;
+
+	//! \brief TODO
+	//! \param a first element
+	//! \param b second element
+	//! \returns TODO
 	virtual Element& Accumulate(Element &a, const Element &b) const;
+
+	//! \brief Reduces an element in the congruence class
+	//! \param a element to reduce
+	//! \param b the congruence class
+	//! \returns the reduced element
 	virtual Element& Reduce(Element &a, const Element &b) const;
 
+	//! \brief Performs a scalar multiplication
+	//! \param a multiplicand
+	//! \param e multiplier
+	//! \returns the product
 	virtual Element ScalarMultiply(const Element &a, const Integer &e) const;
+
+	//! \brief TODO
+	//! \param x first multiplicand
+	//! \param e1 the first multiplier
+	//! \param y second multiplicand
+	//! \param e2 the second multiplier
+	//! \returns TODO
 	virtual Element CascadeScalarMultiply(const Element &x, const Integer &e1, const Element &y, const Integer &e2) const;
 
+	//! \brief Multiplies a base to multiple exponents in a group
+	//! \param results an array of Elements
+	//! \param base the base to raise to the exponents
+	//! \param exponents an array of exponents
+	//! \param exponentsCount the number of exponents in the array
+	//! \details SimultaneousMultiply() multiplies the base to each exponent in the exponents array and stores the
+	//!   result at the respective position in the results array.
+	//! \details SimultaneousMultiply() must be implemented in a derived class.
+	//! \pre <tt>COUNTOF(results) == exponentsCount</tt>
+	//! \pre <tt>COUNTOF(exponents) == exponentsCount</tt>
 	virtual void SimultaneousMultiply(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const;
 };
 
-//! Abstract Ring
+//! \brief Abstract ring
+//! \tparam T element class or type
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 template <class T> class CRYPTOPP_NO_VTABLE AbstractRing : public AbstractGroup<T>
 {
 public:
 	typedef T Element;
 
+	//! \brief Construct an AbstractRing
 	AbstractRing() {m_mg.m_pRing = this;}
+
+	//! \brief Copy construct an AbstractRing
+	//! \param source other AbstractRing
 	AbstractRing(const AbstractRing &source)
 		{CRYPTOPP_UNUSED(source); m_mg.m_pRing = this;}
+
+	//! \brief Assign an AbstractRing
+	//! \param source other AbstractRing
 	AbstractRing& operator=(const AbstractRing &source)
 		{CRYPTOPP_UNUSED(source); return *this;}
 
+	//! \brief Determines whether an element is a unit in the group
+	//! \param a the element
+	//! \returns true if the element is a unit after reduction, false otherwise.
 	virtual bool IsUnit(const Element &a) const =0;
+
+	//! \brief Retrieves the multiplicative identity
+	//! \returns the multiplicative identity
 	virtual const Element& MultiplicativeIdentity() const =0;
+
+	//! \brief Multiplies elements in the group
+	//! \param a the multiplicand
+	//! \param b the multiplier
+	//! \returns the product of a and b
 	virtual const Element& Multiply(const Element &a, const Element &b) const =0;
+
+	//! \brief Calculate the multiplicative inverse of an element in the group
+	//! \param a the element
 	virtual const Element& MultiplicativeInverse(const Element &a) const =0;
 
+	//! \brief Square an element in the group
+	//! \param a the element
+	//! \returns the element squared
 	virtual const Element& Square(const Element &a) const;
+
+	//! \brief Divides elements in the group
+	//! \param a the dividend
+	//! \param b the divisor
+	//! \returns the quotient
 	virtual const Element& Divide(const Element &a, const Element &b) const;
 
+	//! \brief Raises a base to an exponent in the group
+	//! \param a the base
+	//! \param e the exponent
+	//! \returns the exponentiation
 	virtual Element Exponentiate(const Element &a, const Integer &e) const;
+
+	//! \brief TODO
+	//! \param x first element
+	//! \param e1 first exponent
+	//! \param y second element
+	//! \param e2 second exponent
+	//! \returns TODO
 	virtual Element CascadeExponentiate(const Element &x, const Integer &e1, const Element &y, const Integer &e2) const;
 
+	//! \brief Exponentiates a base to multiple exponents in the Ring
+	//! \param results an array of Elements
+	//! \param base the base to raise to the exponents
+	//! \param exponents an array of exponents
+	//! \param exponentsCount the number of exponents in the array
+	//! \details SimultaneousExponentiate() raises the base to each exponent in the exponents array and stores the
+	//!   result at the respective position in the results array.
+	//! \details SimultaneousExponentiate() must be implemented in a derived class.
+	//! \pre <tt>COUNTOF(results) == exponentsCount</tt>
+	//! \pre <tt>COUNTOF(exponents) == exponentsCount</tt>
 	virtual void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const;
 
+	//! \brief Retrieves the multiplicative group
+	//! \returns the multiplicative group
 	virtual const AbstractGroup<T>& MultiplicativeGroup() const
 		{return m_mg;}
 
@@ -124,7 +242,9 @@ private:
 
 // ********************************************************
 
-//! Base and Exponent
+//! \brief Base and exponent
+//! \tparam T base class or type
+//! \tparam T exponent class or type
 template <class T, class E = Integer>
 struct BaseAndExponent
 {
@@ -144,15 +264,37 @@ template <class Element, class Iterator>
 
 // ********************************************************
 
-//! Abstract Euclidean Domain
+//! \brief Abstract Euclidean domain
+//! \tparam T element class or type
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 template <class T> class CRYPTOPP_NO_VTABLE AbstractEuclideanDomain : public AbstractRing<T>
 {
 public:
 	typedef T Element;
 
+	//! \brief Performs the division algorithm on two elements in the ring
+	//! \param r the remainder
+	//! \param q the quotient
+	//! \param a the dividend
+	//! \param d the divisor
 	virtual void DivisionAlgorithm(Element &r, Element &q, const Element &a, const Element &d) const =0;
 
+	//! \brief Performs a modular reduction in the ring
+	//! \param a the element
+	//! \param b the modulus
+	//! \returns the result of <tt>a%b</tt>.
 	virtual const Element& Mod(const Element &a, const Element &b) const =0;
+
+	//! \brief Calculates the greatest common denominator in the ring
+	//! \param a the first element
+	//! \param b the second element
+	//! \returns the the greatest common denominator of a and b.
 	virtual const Element& Gcd(const Element &a, const Element &b) const;
 
 protected:
@@ -161,7 +303,15 @@ protected:
 
 // ********************************************************
 
-//! EuclideanDomainOf
+//! \brief Euclidean domain
+//! \tparam T element class or type
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 template <class T> class EuclideanDomainOf : public AbstractEuclideanDomain<T>
 {
 public:
@@ -224,7 +374,15 @@ private:
 	mutable Element result;
 };
 
-//! Quotient Ring
+//! \brief Quotient ring
+//! \tparam T element class or type
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 template <class T> class QuotientRing : public AbstractRing<typename T::Element>
 {
 public:
diff --git a/modarith.h b/modarith.h
index aa943373..fa430b61 100644
--- a/modarith.h
+++ b/modarith.h
@@ -24,10 +24,13 @@ CRYPTOPP_DLL_TEMPLATE_CLASS AbstractEuclideanDomain<Integer>;
 //! \brief Ring of congruence classes modulo n
 //! \details This implementation represents each congruence class as the smallest
 //!   non-negative integer in that class.
-//! \details Each instance of the class provides two temporary elements to
-//!   preserve intermediate calculations for future use. For example, 
-//!   \ref ModularArithmetic::Multiply "Multiply" saves its last result in member
-//!   variable <tt>m_result1</tt>.
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 class CRYPTOPP_DLL ModularArithmetic : public AbstractRing<Integer>
 {
 public:
@@ -119,7 +122,7 @@ public:
 	const Integer& Identity() const
 		{return Integer::Zero();}
 
-	//! \brief Adds elements in the Ring
+	//! \brief Adds elements in the ring
 	//! \param a first element
 	//! \param b second element
 	//! \returns the sum of <tt>a</tt> and <tt>b</tt>
@@ -131,12 +134,12 @@ public:
 	//! \returns TODO
 	Integer& Accumulate(Integer &a, const Integer &b) const;
 
-	//! \brief Inverts the element in the Ring
+	//! \brief Inverts the element in the ring
 	//! \param a first element
 	//! \returns the inverse of the element
 	const Integer& Inverse(const Integer &a) const;
 
-	//! \brief Subtracts elements in the Ring
+	//! \brief Subtracts elements in the ring
 	//! \param a first element
 	//! \param b second element
 	//! \returns the difference of <tt>a</tt> and <tt>b</tt>. The element <tt>a</tt> must provide a Subtract member function.
@@ -148,7 +151,7 @@ public:
 	//! \returns TODO
 	Integer& Reduce(Integer &a, const Integer &b) const;
 
-	//! \brief Doubles an element in the Ring
+	//! \brief Doubles an element in the ring
 	//! \param a the element
 	//! \returns the element doubled
 	//! \details Double returns <tt>Add(a, a)</tt>. The element <tt>a</tt> must provide an Add member function.
@@ -161,38 +164,38 @@ public:
 	const Integer& MultiplicativeIdentity() const
 		{return Integer::One();}
 
-	//! \brief Multiplies elements in the Ring
-	//! \param a first element
-	//! \param b second element
+	//! \brief Multiplies elements in the ring
+	//! \param a the multiplicand
+	//! \param b the multiplier
 	//! \returns the product of a and b
 	//! \details Multiply returns <tt>a*b\%n</tt>.
 	const Integer& Multiply(const Integer &a, const Integer &b) const
 		{return m_result1 = a*b%m_modulus;}
 
-	//! \brief Square an element in the Ring
+	//! \brief Square an element in the ring
 	//! \param a the element
 	//! \returns the element squared
 	//! \details Square returns <tt>a*a\%n</tt>. The element <tt>a</tt> must provide a Square member function.
 	const Integer& Square(const Integer &a) const
 		{return m_result1 = a.Squared()%m_modulus;}
 
-	//! \brief Determines whether an element is a unit in the Ring
+	//! \brief Determines whether an element is a unit in the ring
 	//! \param a the element
 	//! \returns true if the element is a unit after reduction, false otherwise.
 	bool IsUnit(const Integer &a) const
 		{return Integer::Gcd(a, m_modulus).IsUnit();}
 
-	//! \brief Calculate the multiplicative inverse of an element in the Ring
+	//! \brief Calculate the multiplicative inverse of an element in the ring
 	//! \param a the element
 	//! \details MultiplicativeInverse returns <tt>a<sup>-1</sup>\%n</tt>. The element <tt>a</tt> must
 	//!   provide a InverseMod member function.
 	const Integer& MultiplicativeInverse(const Integer &a) const
 		{return m_result1 = a.InverseMod(m_modulus);}
 
-	//! \brief Divides elements in the Ring
-	//! \param a first element
-	//! \param b second element
-	//! \returns the element squared
+	//! \brief Divides elements in the ring
+	//! \param a the dividend
+	//! \param b the divisor
+	//! \returns the quotient
 	//! \details Divide returns <tt>a*b<sup>-1</sup>\%n</tt>.
 	const Integer& Divide(const Integer &a, const Integer &b) const
 		{return Multiply(a, MultiplicativeInverse(b));}
@@ -205,7 +208,7 @@ public:
 	//! \returns TODO
 	Integer CascadeExponentiate(const Integer &x, const Integer &e1, const Integer &y, const Integer &e2) const;
 
-	//! \brief Exponentiates a base to multiple exponents in the Ring
+	//! \brief Exponentiates a base to multiple exponents in the ring
 	//! \param results an array of Elements
 	//! \param base the base to raise to the exponents
 	//! \param exponents an array of exponents
@@ -217,17 +220,17 @@ public:
 	//! \pre <tt>COUNTOF(exponents) == exponentsCount</tt>
 	void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const;
 
-	//! \brief Provides the maximum bit size of an element in the Ring
+	//! \brief Provides the maximum bit size of an element in the ring
 	//! \returns maximum bit size of an element
 	unsigned int MaxElementBitLength() const
 		{return (m_modulus-1).BitCount();}
 
-	//! \brief Provides the maximum byte size of an element in the Ring
+	//! \brief Provides the maximum byte size of an element in the ring
 	//! \returns maximum byte size of an element
 	unsigned int MaxElementByteLength() const
 		{return (m_modulus-1).ByteCount();}
 
-	//! \brief Provides a random element in the Ring
+	//! \brief Provides a random element in the ring
 	//! \param rng RandomNumberGenerator used to generate material
 	//! \param ignore_for_now unused
 	//! \returns a random element that is uniformly distributed
@@ -261,6 +264,13 @@ protected:
 //! \brief Performs modular arithmetic in Montgomery representation for increased speed
 //! \details The Montgomery representation represents each congruence class <tt>[a]</tt> as
 //!   <tt>a*r\%n</tt>, where <tt>r</tt> is a convenient power of 2.
+//! \details <tt>const Element&</tt> returned by member functions are references
+//!   to internal data members. Since each object may have only
+//!   one such data member for holding results, the following code
+//!   will produce incorrect results:
+//!   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+//!   But this should be fine:
+//!   <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
 class CRYPTOPP_DLL MontgomeryRepresentation : public ModularArithmetic
 {
 public:
diff --git a/pwdbased.h b/pwdbased.h
index 44a19dfe..055c5bd5 100644
--- a/pwdbased.h
+++ b/pwdbased.h
@@ -32,6 +32,7 @@ public:
 	//! \brief Derive key from the password
 	//! \param derived the byte buffer to receive the derived password
 	//! \param derivedLen the size of the byte buffer to receive the derived password
+	//! \param purpose an octet indicating the purpose of the derivation
 	//! \param password the byte buffer with the password
 	//! \param passwordLen the size of the password, in bytes
 	//! \param salt the byte buffer with the salt