IMakeSharesUseCase & IReconstructionUseCase: Initial import

Resolves: No entry

src/Cryptography/FinitePoint`1.cs

@@ -154,39 +154,39 @@ public FinitePoint(Calculator<TNumber> x, Calculator<TNumber> y)
     /// </summary>
     /// <param name="left">The left operand</param>
     /// <param name="right">The right operand</param>
-    /// <returns>Returns <see langword="true"/> if its operands are not equal, otherwise <see langword="false"/>.</returns>
+    /// <returns>Returns <see langword="true"/> if its operands aren't equal, otherwise <see langword="false"/>.</returns>
     public static bool operator !=(FinitePoint<TNumber> left, FinitePoint<TNumber> right) => !left.Equals(right);
 
     /// <summary>
     /// Greater than operator
     /// </summary>
-    /// <param name="left">The 1st operand</param>
-    /// <param name="right">The 2nd operand</param>
-    /// <returns>Returns <see langword="true"/> if its 1st operand is greater than its 2nd operand, otherwise <see langword="false"/>.</returns>
+    /// <param name="left">The first operand</param>
+    /// <param name="right">The second operand</param>
+    /// <returns>Returns <see langword="true"/> if its first operand is greater than its second operand, otherwise <see langword="false"/>.</returns>
     public static bool operator >(FinitePoint<TNumber> left, FinitePoint<TNumber> right) => left.CompareTo(right) == 1;
 
     /// <summary>
     /// Less than operator
     /// </summary>
-    /// <param name="left">The 1st operand</param>
-    /// <param name="right">The 2nd operand</param>
-    /// <returns>Returns <see langword="true"/> if its 1st operand is less than its 2nd operand, otherwise <see langword="false"/>.</returns>
+    /// <param name="left">The first operand</param>
+    /// <param name="right">The second operand</param>
+    /// <returns>Returns <see langword="true"/> if its first operand is less than its second operand, otherwise <see langword="false"/>.</returns>
     public static bool operator <(FinitePoint<TNumber> left, FinitePoint<TNumber> right) => left.CompareTo(right) == -1;
 
     /// <summary>
     /// Greater than or equal operator
     /// </summary>
     /// <param name="left">The 1st operand</param>
-    /// <param name="right">The 2nd operand</param>
-    /// <returns>Returns <see langword="true"/> if its 1st operand is greater than or equal to its 2nd operand, otherwise <see langword="false"/>.</returns>
+    /// <param name="right">The second operand</param>
+    /// <returns>Returns <see langword="true"/> if its first operand is greater than or equal to its second operand, otherwise <see langword="false"/>.</returns>
     public static bool operator >=(FinitePoint<TNumber> left, FinitePoint<TNumber> right) => left.CompareTo(right) >= 0;
 
     /// <summary>
     /// Less than or equal operator
     /// </summary>
-    /// <param name="left">The 1st operand</param>
-    /// <param name="right">The 2nd operand</param>
-    /// <returns>Returns <see langword="true"/> if its 1st operand is less than or equal to its 2nd operand, otherwise <see langword="false"/>.</returns>
+    /// <param name="left">The first operand</param>
+    /// <param name="right">The second operand</param>
+    /// <returns>Returns <see langword="true"/> if its first operand is less than or equal to its second operand, otherwise <see langword="false"/>.</returns>
     public static bool operator <=(FinitePoint<TNumber> left, FinitePoint<TNumber> right) => left.CompareTo(right) <= 0;
 
     /// <inheritdoc />
@@ -251,7 +251,7 @@ private static Calculator<TNumber> Evaluate(IEnumerable<Calculator<TNumber>> pol
     /// Converts a byte collection to hexadecimal string.
     /// </summary>
     /// <param name="bytes"></param>
-    /// <returns>human readable / printable string</returns>
+    /// <returns>human-readable / printable string</returns>
     /// <remarks>
     /// Based on discussion on <see href="https://stackoverflow.com/questions/623104/byte-to-hex-string/5919521#5919521">stackoverflow</see>
     /// </remarks>
@@ -287,8 +287,7 @@ private static string ToHexString(IEnumerable<byte> bytes)
     private static byte[] ToByteArray(string hexString)
         {
             byte[] bytes = new byte[hexString.Length / 2];
-            var hexValues = Array.AsReadOnly(new[]
-            {
+            var hexValues = Array.AsReadOnly([
                 0x00,
                 0x01,
                 0x02,
@@ -312,7 +311,7 @@ private static byte[] ToByteArray(string hexString)
                 0x0D,
                 0x0E,
                 0x0F
-            });
+            ]);
 
             for (int i = 0, j = 0; j < hexString.Length; j += 2, i += 1)
             {

src/Cryptography/IMakeSharesUseCase.cs

@@ -0,0 +1,43 @@
+namespace SecretSharingDotNet.Cryptography;
+
+/// <summary>
+/// Interface for the Shamir's Secret Sharing algorithm implementation for creating shared secrets. 
+/// </summary>
+/// <typeparam name="TNumber">Numeric data type (An integer type)</typeparam>
+public interface IMakeSharesUseCase<TNumber>
+{
+    /// <summary>
+    /// Generates a random shamir pool, returns the random secret and the share points.
+    /// </summary>
+    /// <param name="numberOfMinimumShares">Minimum number of shared secrets for reconstruction</param>
+    /// <param name="numberOfShares">Maximum number of shared secrets</param>
+    /// <param name="securityLevel">Security level (in number of bits). The minimum is 13.</param>
+    /// <returns>A <see cref="Shares{TNumber}"/> object</returns>
+    /// <exception cref="T:System.ArgumentOutOfRangeException">
+    /// The <paramref name="securityLevel"/> parameter is lower than 13 or greater than 43.112.609. OR The <paramref name="numberOfMinimumShares"/> parameter is lower than 2 or greater than <paramref name="numberOfShares"/>.
+    /// </exception>
+    Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberOfShares, int securityLevel);
+
+    /// <summary>
+    /// Generates a random shamir pool, returns the specified <paramref name="secret"/> and the share points.
+    /// </summary>
+    /// <param name="numberOfMinimumShares">Minimum number of shared secrets for reconstruction</param>
+    /// <param name="numberOfShares">Maximum number of shared secrets</param>
+    /// <param name="secret">secret text as <see cref="Secret{TNumber}"/> or see cref="string"/></param>
+    /// <param name="securityLevel">Security level (in number of bits). The minimum is 13.</param>
+    /// <returns>A <see cref="Shares{TNumber}"/> object</returns>
+    /// <exception cref="T:System.ArgumentOutOfRangeException">
+    /// The <paramref name="securityLevel"/> is lower than 13 or greater than 43.112.609. OR <paramref name="numberOfMinimumShares"/> is lower than 2 or greater than <paramref name="numberOfShares"/>.
+    /// </exception>
+    Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberOfShares, Secret<TNumber> secret, int securityLevel);
+
+    /// <summary>
+    /// Generates a random shamir pool, returns the specified <paramref name="secret"/> and the share points.
+    /// </summary>
+    /// <param name="numberOfMinimumShares">Minimum number of shared secrets for reconstruction</param>
+    /// <param name="numberOfShares">Maximum number of shared secrets</param>
+    /// <param name="secret">secret text as <see cref="Secret{TNumber}"/> or see cref="string"/></param>
+    /// <returns>A <see cref="Shares{TNumber}"/> object</returns>
+    /// <exception cref="T:System.ArgumentOutOfRangeException"><paramref name="numberOfMinimumShares"/> is lower than 2 or greater than <paramref name="numberOfShares"/>.</exception>
+    Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberOfShares, Secret<TNumber> secret);
+}

src/Cryptography/IReconstructionUseCase.cs

@@ -0,0 +1,39 @@
+namespace SecretSharingDotNet.Cryptography;
+
+/// <summary>
+/// Interface for the Shamir's Secret Sharing algorithm implementation for reconstructing the secret.
+/// </summary>
+/// <typeparam name="TNumber"></typeparam>
+public interface IReconstructionUseCase<TNumber>
+{
+    /// <summary>
+    /// Recovers the secret from the given <paramref name="shares"/> (points with x and y on the polynomial)
+    /// </summary>
+    /// <param name="shares">Shares represented by <see cref="string"/> and separated by newline.</param>
+    /// <returns>Re-constructed secret</returns>
+    Secret<TNumber> Reconstruction(string shares);
+
+    /// <summary>
+    /// 
+    /// Recovers the secret from the given <paramref name="shares"/> (points with x and y on the polynomial)
+    /// </summary>
+    /// <param name="shares">Shares represented by <see cref="string"/> array.</param>
+    /// <returns>Re-constructed secret</returns>
+    Secret<TNumber> Reconstruction(string[] shares);
+
+    /// <summary>
+    /// Recovers the secret from the given <paramref name="shares"/> (points with x and y on the polynomial)
+    /// </summary>
+    /// <param name="shares">For details <see cref="Shares{TNumber}"/></param>
+    /// <returns>Re-constructed secret</returns>
+    Secret<TNumber> Reconstruction(Shares<TNumber> shares);
+
+    /// <summary>
+    /// Recovers the secret from the given <paramref name="shares"/> (points with x and y on the polynomial)
+    /// </summary>
+    /// <param name="shares">Two or more shares represented by a set of <see cref="FinitePoint{TNumber}"/></param>
+    /// <returns>Re-constructed secret</returns>
+    /// <exception cref="T:System.ArgumentNullException"><paramref name="shares"/> is <see langword="null"/>.</exception>
+    /// <exception cref="T:System.ArgumentOutOfRangeException">The length of <paramref name="shares"/> is lower than 2.</exception>
+    Secret<TNumber> Reconstruction(FinitePoint<TNumber>[] shares);
+}

src/Cryptography/Secret`1.cs

@@ -235,7 +235,7 @@ public static implicit operator Secret<TNumber>(ReadOnlySpan<char> secretText)
     /// </summary>
     /// <param name="left">The left operand</param>
     /// <param name="right">The right operand</param>
-    /// <returns>Returns <see langword="true"/> if its operands are not equal, otherwise <see langword="false"/>.</returns>
+    /// <returns>Returns <see langword="true"/> if its operands aren't equal, otherwise <see langword="false"/>.</returns>
     public static bool operator !=(Secret<TNumber> left, Secret<TNumber> right) => !left.Equals(right);
 
     /// <summary>
@@ -276,8 +276,8 @@ public static implicit operator Secret<TNumber>(ReadOnlySpan<char> secretText)
     /// <param name="other">An <see cref="Secret{TNumber}"/> instance to compare with this instance.</param>
     /// <returns>A value that indicates the relative order of the <see cref="Secret{TNumber}"/> instances being compared.</returns>
     public int CompareTo(Secret<TNumber> other) => this.secretNumber
-        .Subset(0, this.SecretByteSize - MarkByteCount).CompareTo(other.secretNumber
-            .Subset(0, other.SecretByteSize - MarkByteCount));
+        .Subset(0, this.SecretByteSize - MarkByteCount)
+        .CompareTo(other.secretNumber.Subset(0, other.SecretByteSize - MarkByteCount));
 
     /// <summary>
     /// Determines whether this instance and an<paramref name="other"/> specified <see cref="Secret{TNumber}"/> instance are equal.

src/Cryptography/ShamirsSecretSharing`3.cs

@@ -41,9 +41,10 @@ namespace SecretSharingDotNet.Cryptography;
 /// Shamir's secret sharing algorithm
 /// </summary>
 /// <typeparam name="TNumber">Numeric data type</typeparam>
-/// <typeparam name="TExtendedGcdAlgorithm"></typeparam>
-/// <typeparam name="TExtendedGcdResult"></typeparam>
-public class ShamirsSecretSharing<TNumber, TExtendedGcdAlgorithm, TExtendedGcdResult> : ShamirsSecretSharing
+/// <typeparam name="TExtendedGcdAlgorithm">Extended greatest common divisor algorithm</typeparam>
+/// <typeparam name="TExtendedGcdResult">Extended greatest common divisor result</typeparam>
+public class ShamirsSecretSharing<TNumber, TExtendedGcdAlgorithm, TExtendedGcdResult> : ShamirsSecretSharing,
+    IMakeSharesUseCase<TNumber>, IReconstructionUseCase<TNumber>
     where TExtendedGcdAlgorithm : class, IExtendedGcdAlgorithm<TNumber, TExtendedGcdResult>
     where TExtendedGcdResult : struct, IExtendedGcdResult<TNumber>
 {
@@ -70,21 +71,21 @@ public class ShamirsSecretSharing<TNumber, TExtendedGcdAlgorithm, TExtendedGcdRe
     public ShamirsSecretSharing(TExtendedGcdAlgorithm extendedGcd)
     {
         this.extendedGcd = extendedGcd ?? throw new ArgumentNullException(nameof(extendedGcd));
-        this.SecurityLevel = 13;
+        this.SecurityLevel = SecurityLevels[0];
     }
 
     /// <summary>
     /// Gets or sets the security level
     /// </summary>
-    /// <remarks>Value is lower than 13 or greater than 43112609.</remarks>
-    /// <exception cref="T:System.ArgumentOutOfRangeException" accessor="set">Value is lower than 13 or greater than 43112609.</exception>
+    /// <remarks>The value is lower than 13 or greater than 43.112.609.</remarks>
+    /// <exception cref="T:System.ArgumentOutOfRangeException" accessor="set">The value is lower than 13 or greater than 43.112.609.</exception>
     public int SecurityLevel
     {
         get => this.fixedSecurityLevel;
 
         set
         {
-            if (value < 13)
+            if (value < SecurityLevels[0])
             {
                 throw new ArgumentOutOfRangeException(nameof(value), value, ErrorMessages.MinimumSecurityLevelExceeded);
             }
@@ -112,9 +113,11 @@ public int SecurityLevel
     /// </summary>
     /// <param name="numberOfMinimumShares">Minimum number of shared secrets for reconstruction</param>
     /// <param name="numberOfShares">Maximum number of shared secrets</param>
-    /// <param name="securityLevel">Security level (in number of bits). Minimum is 13.</param>
+    /// <param name="securityLevel">Security level (in number of bits). The minimum is 13.</param>
     /// <returns></returns>
-    /// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="securityLevel"/> parameter is lower than 13 or greater than 43112609. OR The <paramref name="numberOfMinimumShares"/> parameter is lower than 2 or greater than <paramref name="numberOfShares"/>.</exception>
+    /// <exception cref="T:System.ArgumentOutOfRangeException">
+    /// The <paramref name="securityLevel"/> parameter is lower than 13 or greater than 43.112.609. OR The <paramref name="numberOfMinimumShares"/> parameter is lower than 2 or greater than <paramref name="numberOfShares"/>.
+    /// </exception>
     public Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberOfShares, int securityLevel)
     {
         try
@@ -156,10 +159,12 @@ public Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberO
     /// <param name="numberOfMinimumShares">Minimum number of shared secrets for reconstruction</param>
     /// <param name="numberOfShares">Maximum number of shared secrets</param>
     /// <param name="secret">secret text as <see cref="Secret{TNumber}"/> or see cref="string"/></param>
-    /// <param name="securityLevel">Security level (in number of bits). Minimum is 13.</param>
+    /// <param name="securityLevel">Security level (in number of bits). The minimum is 13.</param>
     /// <returns></returns>
     /// <remarks>This method can modify the <see cref="SecurityLevel"/> based on the <paramref name="secret"/> length.</remarks>
-    /// <exception cref="T:System.ArgumentOutOfRangeException">The <paramref name="securityLevel"/> is lower than 13 or greater than 43112609. OR <paramref name="numberOfMinimumShares"/> is lower than 2 or greater than <paramref name="numberOfShares"/>.</exception>
+    /// <exception cref="T:System.ArgumentOutOfRangeException">
+    /// The <paramref name="securityLevel"/> is lower than 13 or greater than 43.112.609. OR <paramref name="numberOfMinimumShares"/> is lower than 2 or greater than <paramref name="numberOfShares"/>.
+    /// </exception>
     public Shares<TNumber> MakeShares(TNumber numberOfMinimumShares, TNumber numberOfShares, Secret<TNumber> secret, int securityLevel)
     {
         try
@@ -220,13 +225,11 @@ private Calculator<TNumber>[] CreatePolynomial(int numberOfMinimumShares)
         var polynomial = new Calculator<TNumber>[numberOfMinimumShares];
         polynomial[0] = Calculator<TNumber>.Zero;
         byte[] randomNumber = new byte[this.mersennePrime.ByteCount];
-        using (var rng = RandomNumberGenerator.Create())
+        using var rng = RandomNumberGenerator.Create();
+        for (int i = 1; i < numberOfMinimumShares; i++)
         {
-            for (int i = 1; i < numberOfMinimumShares; i++)
-            {
-                rng.GetBytes(randomNumber);
-                polynomial[i] = (Calculator.Create(randomNumber, typeof(TNumber)) as Calculator<TNumber>)?.Abs() % this.mersennePrime;
-            }
+            rng.GetBytes(randomNumber);
+            polynomial[i] = (Calculator.Create(randomNumber, typeof(TNumber)) as Calculator<TNumber>)?.Abs() % this.mersennePrime;
         }
 
         return polynomial;
@@ -293,7 +296,7 @@ private static Calculator<TNumber> Product(IReadOnlyList<Calculator<TNumber>> va
     /// k points will define a polynomial of up to kth order
     /// </summary>
     /// <param name="finitePoints">The shares represented by a set of <see cref="FinitePoint{TNumber}"/>.</param>
-    /// <param name="prime">A prime number must be defined to avoid computation with real numbers. In fact it is finite field arithmetic.
+    /// <param name="prime">A prime number must be defined to avoid computation with real numbers. In fact, it is finite field arithmetic.
     /// The prime number must be the same as used for the construction of shares.</param>
     /// <exception cref="ArgumentException"></exception>
     /// <returns>The re-constructed secret.</returns>

src/Cryptography/SharedSeparator.cs

@@ -41,5 +41,5 @@ internal static class SharedSeparator
     /// <summary>
     /// Separator array for <see cref="string.Split(char[])"/> method usage to avoid allocation of a new array.
     /// </summary>
-    internal static readonly char[] CoordinateSeparatorArray = { CoordinateSeparator };
+    internal static readonly char[] CoordinateSeparatorArray = [CoordinateSeparator];
 }