Пример #1
0
 /// <summary>
 /// Constructs a new <code>IssuerSetupParameters</code> instance.
 /// </summary>
 public IssuerSetupParameters()
 {
     ip = new IssuerParameters();
     // set the defaults
     ip.UidH           = "SHA-256";
     GroupConstruction = GroupType.Subgroup;
 }
        public static PresentationProof Generate(IssuerParameters ip, int[] disclosed, byte[] message, byte[] messageD, IDevicePresentationContext deviceContext, UProveKeyAndToken upkt, byte[][] attributes)
        {
            GroupElement gs = null;

            FieldZqElement[] unused;
            return(Generate(ip, disclosed, null, 0, gs, message, messageD, deviceContext, upkt, attributes, null, out unused));
        }
Пример #3
0
        /// <summary>
        /// Computes the value x_i.
        /// A field element is computed from an attribute value
        /// </summary>
        /// <param name="ip"> The issuer paramters</param>
        /// <param name="i"> The index of the attribute</param>
        /// <param name="A"> An array contianing the attributes</param>
        /// <returns></returns>
        public static FieldZqElement ComputeXi(IssuerParameters ip, int i, byte[] A)
        {
            FieldZqElement xi;

            if (ip.E[i] == 0x01)            // hash
            {
                if (A == null)
                {
                    xi = ip.Zq.Zero;
                }
                else
                {
                    HashFunction hash = ip.HashFunction;
                    hash.Hash(A);
                    xi = ip.Zq.GetElementFromDigest(hash.Digest);
                }
            }
            else if (ip.E[i] == 0x00)       // do not hash
            {
                if (A == null)
                {
                    throw new ArgumentNullException("A", "A can't be null when ip.E[i] == 0x00");
                }
                else
                {
                    xi = ip.Zq.GetElement(A);
                }
            }
            else
            {
                throw new ArgumentException("invalid E[" + i + "] value");
            }

            return(xi);
        }
Пример #4
0
        void IParametrizedDeserialization.FinishDeserialization(IssuerParameters ip)
        {
            try
            {
                if (!this.deserializationStarted)
                {
                    throw new SerializationException("deserialization not started");
                }

                AlphaInverse = _alphaInverse.ToFieldElementArray(ip.Zq);
                Beta2        = _beta2.ToFieldElementArray(ip.Zq);
                H            = _h.ToGroupElementArray(ip.Gq);
                SigmaZPrime  = _sigmaZPrime.ToGroupElementArray(ip.Gq);
                SigmaAPrime  = _sigmaAPrime.ToGroupElementArray(ip.Gq);
                SigmaBPrime  = _sigmaBPrime.ToGroupElementArray(ip.Gq);
                SigmaCPrime  = _sigmaCPrime.ToFieldElementArray(ip.Zq);

                Validate();
            }
            catch
            {
                throw;
            }
            finally
            {
                this.deserializationStarted = false;
            }
        }
 /// <summary>
 /// Constructs a <code>VerifierPresentationProtocolParameters</code> instance.
 /// </summary>
 /// <param name="ip">The issuer parameters.</param>
 /// <param name="disclosed">Disclosed attribute indices.</param>
 /// <param name="message">Presentation message.</param>
 /// <param name="token">Presented token.</param>
 public VerifierPresentationProtocolParameters(IssuerParameters ip, int[] disclosed, byte[] message, UProveToken token)
 {
     IP        = ip;
     Disclosed = disclosed;
     Message   = message;
     Token     = token;
 }
Пример #6
0
        /// <summary>
        /// Constructs a new <code>Prover</code> instance.
        /// </summary>
        /// <param name="ip">The Issuer parameters.</param>
        /// <param name="psms">The post second message state.</param>
        public Prover(IssuerParameters ip, PostSecondMessageState psms)
        {
            psms.Validate();

            this.ip                = ip;
            this.numberOfTokens    = psms.AlphaInverse.Length;
            this.TI                = psms.TI;
            this.PI                = psms.PI;
            this.isDeviceProtected = psms.IsDeviceProtected;
            this.beta2             = psms.Beta2;

            this.h           = psms.H;
            this.sigmaZPrime = psms.SigmaZPrime;
            this.sigmaAPrime = psms.SigmaAPrime;
            this.sigmaBPrime = psms.SigmaBPrime;
            this.sigmaCPrime = psms.SigmaCPrime;

            ukat = new UProveKeyAndToken[numberOfTokens];
            for (int i = 0; i < numberOfTokens; i++)
            {
                ukat[i]            = new UProveKeyAndToken();
                ukat[i].PrivateKey = psms.AlphaInverse[i];
            }

            state = State.Second;
        }
Пример #7
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        /// <summary>
        /// Verifies a U-Prove token signature.
        /// </summary>
        /// <param name="ip">The Issuer parameters corresponding to the U-Prove token.</param>
        /// <param name="upt">The U-Prove token to verify.</param>
        /// <exception cref="InvalidUProveArtifactException">If the U-Prove token is invalid.</exception>
        public static void VerifyTokenSignature(IssuerParameters ip, UProveToken upt)
        {
            Group   Gq = ip.Gq;
            FieldZq Zq = ip.Zq;

            if (upt.H == Gq.Identity)
            {
                throw new InvalidUProveArtifactException("Invalid U-Prove token (public key H = 1)");
            }
            GroupElement[]   bases     = new GroupElement[2];
            FieldZqElement[] exponents = new FieldZqElement[2];

            HashFunction hash = ip.HashFunction;

            hash.Hash(upt.H);
            hash.Hash(upt.PI);
            hash.Hash(upt.SigmaZPrime);
            bases[0] = Gq.G; exponents[0] = upt.SigmaRPrime;
            bases[1] = ip.G[0]; exponents[1] = upt.SigmaCPrime.Negate();
            hash.Hash(Gq.MultiExponentiate(bases, exponents));
            bases[0] = upt.H; exponents[0] = upt.SigmaRPrime;
            bases[1] = upt.SigmaZPrime; exponents[1] = upt.SigmaCPrime.Negate();
            hash.Hash(Gq.MultiExponentiate(bases, exponents));
            if (upt.SigmaCPrime != Zq.GetElementFromDigest(hash.Digest))
            {
                throw new InvalidUProveArtifactException("Invalid U-Prove token signature");
            }
        }
Пример #8
0
 void IParametrizedDeserialization.FinishDeserialization(IssuerParameters ip)
 {
     try
     {
         if (!this.deserializationStarted)
         {
             throw new SerializationException("deserialization not started");
         }
         h0     = _h0.ToGroupElement(ip);
         CGamma = _CGamma.ToGroupElement(ip);
         Ch0    = _Ch0.ToGroupElement(ip);
         if (_responses_values.Length != _responses_keys.Length)
         {
             throw new UProveSerializationException("number of response keys does not match number of response values");
         }
         responses = new Dictionary <string, FieldZqElement>();
         for (int i = 0; i < _responses_keys.Length; i++)
         {
             responses.Add(_responses_keys[i], _responses_values[i].ToFieldElement(ip));
         }
         if (presentation != null)
         {
             (presentation as IParametrizedDeserialization).FinishDeserialization(ip);
         }
     }
     catch
     {
         throw;
     }
     finally
     {
         this.deserializationStarted = false;
     }
 }
Пример #9
0
        // Private helper function
        private static byte[] ComputeChallenge(IssuerParameters ip, GroupElement h0, GroupElement CGamma,
                                               GroupElement Ch0, GroupElement[] C, GroupElement tildeD, GroupElement tildeCgamma, GroupElement tildeT,
                                               GroupElement[] tildeC, byte[] message)
        {
            HashFunction H = ip.HashFunction;

            H.Hash(ip.Digest(false));
            H.Hash(h0);
            H.Hash(CGamma);
            H.Hash(Ch0);
            H.Hash(C);
            H.Hash(tildeD);
            H.Hash(tildeCgamma);
            H.Hash(tildeT);
            H.Hash(tildeC);
            H.Hash(message);

            byte[] digest = H.Digest;

#if DEBUG
            Debug.WriteLine("h0 = " + BitConverter.ToString(h0.GetEncoded()));
            Debug.WriteLine("CGamma = " + BitConverter.ToString(CGamma.GetEncoded()));
            Debug.WriteLine("Ch0 = " + BitConverter.ToString(Ch0.GetEncoded()));
            if (tildeC != null)
            {
                Debug.WriteLine("tildeC[0] = " + BitConverter.ToString(tildeC[0].GetEncoded()));
            }
            Debug.WriteLine("tildeD = " + BitConverter.ToString(tildeD.GetEncoded()));
            Debug.WriteLine("tildeT = " + BitConverter.ToString(tildeT.GetEncoded()));
            Debug.WriteLine("tildeCgamma = " + BitConverter.ToString(tildeCgamma.GetEncoded()));
            Debug.WriteLine("digest = " + BitConverter.ToString(digest));
#endif

            return(digest);
        }
Пример #10
0
 /// <summary>
 /// Constructs a new <code>Prover</code> instance.
 /// </summary>
 /// <param name="ip">The Issuer parameters.</param>
 /// <param name="numberOfTokens">Number of tokens to issue.</param>
 /// <param name="gamma">The gamma value encoding the token attributes.</param>
 /// <param name="TI">The token information field value.</param>
 /// <param name="PI">The Prover information field value.</param>
 /// <param name="preGeneratedRandomData">Optional pregenerated ProverRandomData instance.</param>
 /// <param name="isDeviceProtected">True if the token is to be device-protected, false otherwise.</param>
 /// <param name="batchValidationSecurityLevel">The security level of the batch token signature validation. Given a security level <code>l</code>,
 /// the probability for the Prover to accept an invalid token is <code>2^-l</code>. If set to 0, than
 /// regular validation is used. A value of 20 is recommended.</param>
 internal Prover(IssuerParameters ip, int numberOfTokens, GroupElement gamma, byte[] TI, byte[] PI, ProverRandomData preGeneratedRandomData, bool isDeviceProtected, ushort batchValidationSecurityLevel)
 {
     if (ip == null)
     {
         throw new ArgumentNullException("ip");
     }
     this.ip = ip;
     if (numberOfTokens <= 0)
     {
         throw new ArgumentException("numberOfTokens must be greater than 0");
     }
     this.numberOfTokens = numberOfTokens;
     this.TI             = TI;
     this.PI             = PI;
     if (preGeneratedRandomData != null &&
         (preGeneratedRandomData.Alpha.Length != numberOfTokens ||
          preGeneratedRandomData.Beta1.Length != numberOfTokens ||
          preGeneratedRandomData.Beta2.Length != numberOfTokens))
     {
         throw new ArgumentException("invalid preGeneratedRandomData");
     }
     this.isDeviceProtected            = isDeviceProtected;
     this.batchValidationSecurityLevel = batchValidationSecurityLevel;
     this.gamma = gamma;
     Precompute(gamma, preGeneratedRandomData);
 }
Пример #11
0
        private void Precompute(GroupElement gamma, FieldZqElement[] preGenW)
        {
            IssuerParameters ip = ikap.IssuerParameters;
            Group            Gq = ip.Gq;
            FieldZq          Zq = ip.Zq;

            sigmaZ = gamma.Exponentiate(ikap.PrivateKey);
            if (preGenW == null)
            {
                w = Zq.GetRandomElements(numberOfTokens, false);
            }
            else
            {
                w = preGenW;
            }

            sigmaA = new GroupElement[numberOfTokens];
            sigmaB = new GroupElement[numberOfTokens];
            for (int i = 0; i < numberOfTokens; i++)
            {
                sigmaA[i] = Gq.G.Exponentiate(w[i]);
                sigmaB[i] = gamma.Exponentiate(w[i]);
            }
            state = State.Initialized;
        }
Пример #12
0
        public static PresentationProof Generate(IssuerParameters ip, int[] disclosed, int[] committed, int pseudonymAttribIndex, GroupElement gs, byte[] message, byte[] messageD, IDevicePresentationContext deviceContext, UProveKeyAndToken upkt, byte[][] attributes, ProofGenerationRandomData preGenW, out FieldZqElement[] tildeO)
        {
            CommitmentPrivateValues cpv;
            PresentationProof       proof = Generate(ip, disclosed, committed, pseudonymAttribIndex, gs, message, messageD, deviceContext, upkt, attributes, preGenW, out cpv);

            tildeO = cpv.TildeO;
            return(proof);
        }
 /// <summary>
 /// Constructs a <code>ProverPresentationProtocolParameters</code> instance.
 /// </summary>
 /// <param name="ip">The issuer parameters.</param>
 /// <param name="disclosed">Disclosed attribute indices.</param>
 /// <param name="message">Presentation message.</param>
 /// <param name="keyAndToken">Presented key and token.</param>
 /// <param name="attributes">Token attributes.</param>
 public ProverPresentationProtocolParameters(IssuerParameters ip, int[] disclosed, byte[] message, UProveKeyAndToken keyAndToken, byte[][] attributes)
 {
     IP          = ip;
     Disclosed   = disclosed;
     Message     = message;
     KeyAndToken = keyAndToken;
     Attributes  = attributes;
 }
Пример #14
0
        /// <summary>
        /// Generates the Issuer parameters cryptographic data, <code>ip</code> will be updated with the cryptographic data.
        /// </summary>
        /// <param name="ip">An instanciated Issuer parameters; the Gq and E properties must be set.</param>
        /// <param name="gValues">The issuer generators to use, or null.</param>
        /// <param name="supportDevice">Indicates if the device generator must be generated.</param>
        /// <returns>The Issuer parameters private key.</returns>
        internal static FieldZqElement GenerateIssuerParametersCryptoData(IssuerParameters ip, GroupElement[] gValues, bool supportDevice)
        {
            if (ip == null)
            {
                throw new ArgumentNullException("ip");
            }
            if (ip.Gq == null)
            {
                throw new ArgumentException("Group description is not set");
            }

            //int n = ip.E == null ? 0 : ip.E.Length;
            // extension by Fablei
            int n = ip.MaxNumberOfAttributes;

            Group Gq = ip.Gq;

            ip.G = new GroupElement[n + 2];

            FieldZqElement privateKey;

            if (gValues == null)
            {
                FieldZqElement[] y = ip.Zq.GetRandomElements(n + 2, false);
                privateKey = y[0];

                for (int i = 0; i < (n + 2); i++)
                {
                    ip.G[i] = Gq.G.Exponentiate(y[i]);
                }
            }
            else
            {
                // g_0
                privateKey = ip.Zq.GetRandomElement(false);
                ip.G[0]    = Gq.G.Exponentiate(privateKey);

                // g_1,..,g_n
                for (int i = 1; i < (n + 1); i++)
                {
                    ip.G[i] = gValues[i - 1];
                }

                // g_t
                int t = n + 1;
                ip.G[t] = gValues[gValues.Length - 1];
            }

            if (supportDevice)
            {
                if (ip.Gd == null)
                {
                    ip.Gd = Gq.G.Exponentiate(ip.Zq.GetRandomElement(false));
                }
            }
            return(privateKey);
        }
Пример #15
0
        internal static FieldZqElement ComputeXt(IssuerParameters ip, byte[] TI, bool supportDevice)
        {
            HashFunction hash = ip.HashFunction;

            hash.Hash((byte)1);
            hash.Hash(ip.Digest(supportDevice));
            hash.Hash(TI);
            return(ip.Zq.GetElementFromDigest(hash.Digest));
        }
Пример #16
0
 /// <summary>
 /// Constructs new issuance protocol parameters for the Prover.
 /// </summary>
 /// <param name="ip">The Issuer parameters.</param>
 public ProverProtocolParameters(IssuerParameters ip)
 {
     if (ip == null)
     {
         throw new ArgumentNullException("ip");
     }
     IssuerParameters             = ip;
     BatchValidationSecurityLevel = 0; // defaults to normal validation
 }
Пример #17
0
        /// <summary>
        /// Computes the U-Prove token identifier.
        /// </summary>
        /// <param name="ip">The issuer parameters associated with <code>upt</code>.</param>
        /// <param name="upt">The U-Prove token from which to compute the identifier.</param>
        /// <returns></returns>
        public static byte[] ComputeTokenID(IssuerParameters ip, UProveToken upt)
        {
            HashFunction hash = ip.HashFunction;

            hash.Hash(upt.H);
            hash.Hash(upt.SigmaZPrime);
            hash.Hash(upt.SigmaCPrime);
            hash.Hash(upt.SigmaRPrime);
            return(hash.Digest);
        }
Пример #18
0
        internal static FieldZqElement GenerateChallenge(IssuerParameters ip, UProveToken upt, byte[] a, int pseudonymIndex, byte[] ap, GroupElement Ps, byte[] m, byte[] md, int[] disclosed, FieldZqElement[] disclosedX, int[] committed, CommitmentValues[] commitments, out byte[] mdPrime)
        {
            bool hasCommitments = (committed != null && committed.Length > 0);

            if (hasCommitments)
            {
                if (committed.Length != commitments.Length)
                {
                    throw new ArgumentException("Inconsistent committed indices and commitment values");
                }
            }

            HashFunction hash = ip.HashFunction;

            hash.Hash(ComputeTokenID(ip, upt));
            hash.Hash(a);
            hash.Hash(disclosed);
            hash.Hash(disclosedX);
            if (!hasCommitments)
            {
                hash.HashNull(); // C
                hash.HashNull(); // < {tildeC} >
                hash.HashNull(); // < {tildeA} >
            }
            else
            {
                hash.Hash(committed);
                hash.Hash(commitments.Length); // length of < {tildeC} >
                for (int i = 0; i < commitments.Length; i++)
                {
                    hash.Hash(commitments[i].TildeC);
                }
                hash.Hash(commitments.Length); // length of < {tildeA} >
                for (int i = 0; i < commitments.Length; i++)
                {
                    hash.Hash(commitments[i].TildeA);
                }
            }
            hash.Hash(pseudonymIndex == PresentationProof.DeviceAttributeIndex ? 0 : pseudonymIndex);
            hash.Hash(ap);
            hash.Hash(Ps);
            hash.Hash(m);
            mdPrime = hash.Digest;
            if (upt.IsDeviceProtected)
            {
                hash = ip.HashFunction;
                hash.Hash(md);
                hash.Hash(mdPrime);
                return(ip.Zq.GetElementFromDigest(hash.Digest));
            }
            else
            {
                return(ip.Zq.GetElementFromDigest(mdPrime));
            }
        }
Пример #19
0
        /// <summary>
        /// Constructs a new <code>IssuerSetupParameters</code> instance.
        /// </summary>
        /// <param name="maxNumberOfAttributes">maximum number of attributes, the issuer will be able to include into an issued token - extension by Fablei</param>
        public IssuerSetupParameters(int maxNumberOfAttributes)
        {
            ip = new IssuerParameters(maxNumberOfAttributes);

            // extension by Fablei
            MaxNumberOfAttributes = maxNumberOfAttributes;

            // set the defaults
            ip.UidH           = "SHA-256";
            GroupConstruction = GroupType.ECC;
        }
Пример #20
0
 /// <summary>
 /// Convert a base64 string to a GroupElement using Gq from an IssuerParameters object.
 /// </summary>
 /// <param name="encodedString">The encoded string to convert.</param>
 /// <param name="issuerParameters">The issuer parameters object to use for conversion.</param>
 /// <returns>The converted object.</returns>
 public static GroupElement ToGroupElement(this String encodedString, IssuerParameters issuerParameters)
 {
     if (encodedString == null)
     {
         return(null);
     }
     if (issuerParameters == null)
     {
         throw new ArgumentNullException("issuerParameters");
     }
     return(issuerParameters.Gq.CreateGroupElement(encodedString.ToByteArray()));
 }
Пример #21
0
 /// <summary>
 /// Convert a base64 string to a FieldElement using FieldZq from a particular IssuerParameters object.
 /// </summary>
 /// <param name="encodedString">The encoded string to convert.</param>
 /// <param name="issuerParameters">The IssuerParameters object.</param>
 /// <returns>The converted object.</returns>
 public static FieldZqElement ToFieldElement(this String encodedString, IssuerParameters issuerParameters)
 {
     if (encodedString == null)
     {
         return(null);
     }
     if (issuerParameters == null)
     {
         throw new ArgumentNullException("issuerParameters");
     }
     return(issuerParameters.Zq.GetElement(Convert.FromBase64String(encodedString)));
 }
Пример #22
0
 /// <summary>
 /// Constructs an IssuerKeyAndParameters instance.
 /// </summary>
 /// <param name="privateKey">The private key.</param>
 /// <param name="issuerParameters">The Issuer parameters.</param>
 public IssuerKeyAndParameters(FieldZqElement privateKey, IssuerParameters issuerParameters)
 {
     if (privateKey == null)
     {
         throw new ArgumentNullException("privateKey");
     }
     if (issuerParameters == null)
     {
         throw new ArgumentNullException("issuerParameters");
     }
     this.privateKey       = privateKey;
     this.issuerParameters = issuerParameters;
 }
Пример #23
0
        internal void OnDeserialized(StreamingContext context)
        {
            if (_issuerParameters == null)
            {
                throw new UProveSerializationException("ip");
            }
            if (_privateKey == null)
            {
                throw new UProveSerializationException("key");
            }

            this.issuerParameters = _issuerParameters;
            this.privateKey       = _privateKey.ToFieldElement(this.issuerParameters);
        }
Пример #24
0
        void IParametrizedDeserialization.FinishDeserialization(IssuerParameters ip)
        {
            try
            {
                if (!this.deserializationStarted)
                {
                    throw new SerializationException("deserialization not started");
                }

                bool hasCommitments = false;
                if (_ta != null || _tc != null || _tr != null)
                {
                    if (_ta == null || _tc == null || _tr == null || _ta.Length != _tc.Length || _ta.Length != _tr.Length)
                    {
                        throw new UProveSerializationException("Inconsistent commitment values");
                    }
                    hasCommitments = true;
                }

                this.R = new FieldZqElement[_r.Length];
                for (int i = 0; i < _r.Length; i++)
                {
                    this.R[i] = _r[i].ToFieldZqElement(ip.Zq);
                }

                if (_ps != null)
                {
                    this.Ps = _ps.ToGroupElement(ip);
                }
                if (hasCommitments)
                {
                    this.Commitments = new CommitmentValues[_tc.Length];
                    for (int i = 0; i < _tc.Length; i++)
                    {
                        this.Commitments[i] = new CommitmentValues(
                            _tc[i].ToGroupElement(ip),
                            _ta[i].ToByteArray(),
                            _tr[i].ToFieldElement(ip));
                    }
                }
            }
            catch
            {
                throw;
            }
            finally
            {
                this.deserializationStarted = false;
            }
        }
Пример #25
0
        /// <summary>
        /// Constructs an Issuer parameters instance from a serialized string
        /// </summary>
        public IssuerParameters(string serializedIssuerParameters)
        {
            IssuerParameters.serializer = new Serializer();

            IssuerParameters issuerParameters = this.Deserialize <IssuerParameters>(serializedIssuerParameters);

            this.uidp  = issuerParameters.uidp;
            this.group = issuerParameters.group;
            this.uidh  = issuerParameters.uidh;
            this.g     = issuerParameters.g;
            this.gd    = issuerParameters.gd;
            this.e     = issuerParameters.e;
            this.s     = issuerParameters.s;
            this.usesRecommendedParameters = issuerParameters.usesRecommendedParameters;
        }
Пример #26
0
        /// <summary>
        /// Constructs an Issuer parameters instance from a serialized string
        /// </summary>
        public IssuerParameters(string serializedIssuerParameters)
        {
            IssuerParameters.serializer = new Serializer();

            IssuerParameters issuerParameters = this.Deserialize <IssuerParameters>(serializedIssuerParameters);

            this.uidp  = issuerParameters.uidp;
            this.group = issuerParameters.group;
            this.uidh  = issuerParameters.uidh;
            this.g     = issuerParameters.g;
            this.gd    = issuerParameters.gd;
            this.e     = issuerParameters.e;
            this.s     = issuerParameters.s;
            this.usesRecommendedParameters = issuerParameters.usesRecommendedParameters;

            // extension by Fablei
            MaxNumberOfAttributes = issuerParameters.MaxNumberOfAttributes;
        }
Пример #27
0
 void IParametrizedDeserialization.FinishDeserialization(IssuerParameters ip)
 {
     try
     {
         if (!this.deserializationStarted)
         {
             throw new SerializationException("deserialization not started");
         }
         this.sigmaR = _sigmaR.ToFieldElementArray(ip.Zq);
     }
     catch
     {
         throw;
     }
     finally
     {
         this.deserializationStarted = false;
     }
 }
Пример #28
0
        /// <summary>
        /// Computes the value <c>gamma</c>, an input to the issuance protocol.
        /// </summary>
        /// <param name="ip">The issuer parameters</param>
        /// <param name="A"> The attribute values, or null if the token contains no attributes </param>
        /// <param name="TI">The token information field</param>
        /// <param name="hd">The device public key, or <c>null</c> if device binding is not supported by the issuer paramters.</param>
        /// <returns>The group element gamma </returns>
        public static GroupElement ComputeIssuanceInput(IssuerParameters ip, byte[][] A, byte[] TI, GroupElement hd)
        {
            if (ip == null)
            {
                throw new ArgumentNullException("Issuer parameters are null");
            }
            int  n             = 0;
            bool supportDevice = (hd != null);

            if (supportDevice && !ip.IsDeviceSupported)
            {
                throw new InvalidOperationException("Issuer parameters does not support devices");
            }
            if (A != null)
            {
                n = A.Length;
            }
            Group Gq = ip.Gq;

            GroupElement[]   bases     = new GroupElement[n + 1];
            FieldZqElement[] exponents = new FieldZqElement[n + 1];
            for (int i = 0; i < n; i++)
            {
                FieldZqElement xi = ComputeXi(ip, i, A[i]);
                bases[i]     = ip.G[i + 1];
                exponents[i] = xi;
            }

            FieldZqElement xt = ComputeXt(ip, TI, supportDevice);

            bases[n]     = ip.G[n + 1];
            exponents[n] = xt;

            GroupElement gamma = ip.G[0] * Gq.MultiExponentiate(bases, exponents);

            // Multiply-in the device public key for device-protected tokens
            if (supportDevice)
            {
                gamma = gamma * hd;
            }
            return(gamma);
        }
Пример #29
0
 /// <summary>
 /// Indicates that attributes are carried over from the source token into the new one.
 /// </summary>
 /// <param name="sourceIndex">The indices of the attributes in the existing token.</param>
 /// <param name="destinationIndex">The indices of the attributes in the new token.</param>
 /// /// <param name="sourceIP">The Issuer Parameters used to issue the source token. This can be the same as <c>Ip</c> if the
 /// same Issuer issues the source and new tokens.</param>
 /// <param name="sourceToken">The source token.</param>
 public void CarryOverAttribute(int[] sourceIndex, int[] destinationIndex, IssuerParameters sourceIP, UProveToken sourceToken)
 {
     if (sourceIndex == null || destinationIndex == null || sourceIP == null || sourceToken == null)
     {
         throw new ArgumentNullException("arguments can't be null");
     }
     if (sourceIndex.Length != destinationIndex.Length)
     {
         throw new ArgumentException("sourceIndex and destinationIndex must have the same lenght");
     }
     if (!sourceToken.Uidp.SequenceEqual <byte>(sourceIP.UidP))
     {
         throw new ArgumentException("sourceToken and sourceIP do not match");
     }
     C        = destinationIndex;
     Corig    = sourceIndex;
     SourceIP = sourceIP;
     Tokens   = sourceToken;
     HasCarryOverAttributes = true;
 }
Пример #30
0
        void IParametrizedDeserialization.FinishDeserialization(IssuerParameters ip)
        {
            try
            {
                if (!this.deserializationStarted)
                {
                    throw new SerializationException("deserialization not started");
                }

                this.PrivateKey = _key.ToFieldZqElement(ip.Zq);
                (this.Token as IParametrizedDeserialization).FinishDeserialization(ip);
            }
            catch
            {
                throw;
            }
            finally
            {
                this.deserializationStarted = false;
            }
        }