public static byte[] VerifySSAD(ICCDynamicDataType iccDDType, KernelDatabaseBase database, CAPublicKeyCertificate caPublicKey, byte[] sdadRaw)
{
//section 5.4 of EMV book 2 - SDA
//1.If the Signed Static Application Data has a length different from the
//length of the ICC Public Key Modulus, SDA has failed
IssuerPublicKeyCertificate ipk = IssuerPublicKeyCertificate.BuildAndValidatePublicKey(database, caPublicKey.Modulus, caPublicKey.Exponent);
if (ipk == null)
{
return(null);
}
if (sdadRaw.Length != ipk.Modulus.Length)
{
return(null);
}
//2.In order to obtain the Recovered Data specified in Table 7, apply the
//recovery function specified in Annex A2.1 on the Signed Static Application
//Data using the Issuer Public Key in conjunction with the corresponding
//algorithm.If the Recovered Data Trailer is not equal to 'BC', SDA has
//failed.
byte[] decrypted = PublicKeyCertificate.DecryptRSA(sdadRaw, ipk.Modulus, ipk.Exponent);
SSAD ssad = new SSAD(decrypted);
//3.Check the Recovered Data Header. If it is not '6A', SDA has failed.
if (ssad.DataHeader != 0x6A)
{
return(null);
}
//4.Check the Signed Data Format. If it is not '03', SDA has failed.
//For Visa specialpurpose readers it may return 0x93 if offline data authentication is supported for online transactions (in the TTQ)
if (ssad.SignedDataFormat != 0x03 && ssad.SignedDataFormat != 0x05 && ssad.SignedDataFormat != 0x95)
{
return(null);
}
//5.Concatenate from left to right the second to the fifth data elements in
//Table 7(that is, Signed Data Format through Pad Pattern), followed by
//the static data to be authenticated as specified in section 10.3 of Book 3.If
//the Static Data Authentication Tag List is present and contains tags other
//than '82', then SDA has failed
byte[] dataForHash = ssad.Concat(database.StaticDataToBeAuthenticated.BuildStaticDataToBeAuthenticated());
//6.Apply the indicated hash algorithm(derived from the Hash Algorithm
//Indicator) to the result of the concatenation of the previous step to
//produce the hash result.
byte[] hash = SHA1.Create().ComputeHash(dataForHash);
//7.Compare the calculated hash result from the previous step with the
//recovered Hash Result.If they are not the same, SDA has failed.
if (Formatting.ByteArrayToHexString(ssad.HashResult) != Formatting.ByteArrayToHexString(hash))
{
return(null);
}
return(ssad.DataAuthenticationCode);
}
public static ICCDynamicData VerifySDAD(ICCDynamicDataType iccDDType, KernelDatabaseBase database, CAPublicKeyCertificate caPublicKey, byte[] sdadRaw)
{
//section 6.5.2 of EMV book 2 - DDA
//1.If the Signed Dynamic Application Data has a length different from the
//length of the ICC Public Key Modulus, CDA has failed
IssuerPublicKeyCertificate ipk = IssuerPublicKeyCertificate.BuildAndValidatePublicKey(database, caPublicKey.Modulus, caPublicKey.Exponent);
if (ipk == null)
{
return(null);
}
IccPublicKeyCertificate iccpk = IccPublicKeyCertificate.BuildAndValidatePublicKey(database, database.StaticDataToBeAuthenticated, ipk.Modulus, ipk.Exponent);
if (iccpk == null)
{
return(null);
}
if (sdadRaw.Length != iccpk.Modulus.Length)
{
return(null);
}
//2.To obtain the recovered data specified in Table 22, apply the recovery
//function as specified in Annex A2.1 on the Signed Dynamic Application
//Data using the ICC Public Key in conjunction with the corresponding
//algorithm.If the Recovered Data Trailer is not equal to 'BC', CDA has
//failed
byte[] decrypted = PublicKeyCertificate.DecryptRSA(sdadRaw, iccpk.Modulus, iccpk.Exponent);
SDAD sdad = new SDAD(decrypted);
//3.Check the Recovered Data Header. If it is not '6A', CDA has failed.
if (sdad.DataHeader != 0x6A)
{
return(null);
}
//4.Check the Signed Data Format. If it is not '05', CDA has failed.
//For Visa specialpurpose readers it may return 0x95 iff offline data authentication is supported for online transactions (in the TTQ)
if (sdad.SignedDataFormat != 0x05 && sdad.SignedDataFormat != 0x95)
{
return(null);
}
ICCDynamicData iccDD = new ICCDynamicData(database, sdad.ICCDynamicData, iccDDType);
//5.Concatenate from left to right the second to the sixth data elements in
//Table 17(that is, Signed Data Format through Pad Pattern), followed by
//the data elements specified by the DDOL.
TLV ddol = database.Get(EMVTagsEnum.DYNAMIC_DATA_AUTHENTICATION_DATA_OBJECT_LIST_DDOL_9F49_KRN);
byte[] ddolRelatedData;
if (ddol == null)
{
TLV unpred = database.Get(EMVTagsEnum.UNPREDICTABLE_NUMBER_9F37_KRN);
unpred.Val.PackValue(unpred.Val.GetLength());
ddolRelatedData = unpred.Value;
}
else
{
ddolRelatedData = CommonRoutines.PackRelatedDataTag(database, ddol);
}
byte[] dataForHash = sdad.Concat(ddolRelatedData);
//6.Apply the indicated hash algorithm(derived from the Hash Algorithm
//Indicator) to the result of the concatenation of the previous step to
//produce the hash result.
byte[] hash = SHA1.Create().ComputeHash(dataForHash);
//7.Compare the calculated hash result from the previous step with the
//recovered Hash Result.If they are not the same, DDA has failed.
if (Formatting.ByteArrayToHexString(sdad.HashResult) != Formatting.ByteArrayToHexString(hash))
{
return(null);
}
return(iccDD);
}
public static ICCDynamicData VerifySDAD_K3(ICCDynamicDataType iccDDType, KernelDatabaseBase database, CAPublicKeyCertificate caPublicKey, byte[] sdadRaw)
{
//section 6.5.2 of EMV book 2 - DDA
//1.If the Signed Dynamic Application Data has a length different from the
//length of the ICC Public Key Modulus, CDA has failed
IssuerPublicKeyCertificate ipk = IssuerPublicKeyCertificate.BuildAndValidatePublicKey(database, caPublicKey.Modulus, caPublicKey.Exponent);
if (ipk == null)
{
return(null);
}
IccPublicKeyCertificate iccpk = IccPublicKeyCertificate.BuildAndValidatePublicKey(database, database.StaticDataToBeAuthenticated, ipk.Modulus, ipk.Exponent);
if (iccpk == null)
{
return(null);
}
if (sdadRaw.Length != iccpk.Modulus.Length)
{
return(null);
}
//2.To obtain the recovered data specified in Table 22, apply the recovery
//function as specified in Annex A2.1 on the Signed Dynamic Application
//Data using the ICC Public Key in conjunction with the corresponding
//algorithm.If the Recovered Data Trailer is not equal to 'BC', CDA has
//failed
byte[] decrypted = PublicKeyCertificate.DecryptRSA(sdadRaw, iccpk.Modulus, iccpk.Exponent);
SDAD sdad = new SDAD(decrypted);
//3.Check the Recovered Data Header. If it is not '6A', CDA has failed.
if (sdad.DataHeader != 0x6A)
{
return(null);
}
//4.Check the Signed Data Format. If it is not '05', CDA has failed.
//For Visa specialpurpose readers it may return 0x95 iff offline data authentication is supported for online transactions (in the TTQ)
if (sdad.SignedDataFormat != 0x05 && sdad.SignedDataFormat != 0x95)
{
return(null);
}
ICCDynamicData iccDD = new ICCDynamicData(database, sdad.ICCDynamicData, iccDDType);
//5.Concatenate from left to right the second to the sixth data elements in
//Table 17(that is, Signed Data Format through Pad Pattern), followed by
//the data elements specified by the DDOL.
//C.1 K3 Kernel wants it done this way rather than they way sepecified in step 5
//The Terminal Dynamic Data elements input to the hash algorithm shall be as
//specified in Table C-1 instead of being specified in the DDOL(as the DDOL is
//not a recognized data element for Kernel 3).The kernel may treat the tags
//specified in Table C-1 as default DDOLs for fDDA version '01'
List <byte[]> hashList = new List <byte[]>
{
database.Get(EMVTagsEnum.UNPREDICTABLE_NUMBER_9F37_KRN).Value,
database.Get(EMVTagsEnum.AMOUNT_AUTHORISED_NUMERIC_9F02_KRN).Value,
database.Get(EMVTagsEnum.TRANSACTION_CURRENCY_CODE_5F2A_KRN).Value,
database.Get(EMVTagsEnum.CARD_AUTHENTICATION_RELATED_DATA_9F69_KRN3).Value
};
//6.Apply the indicated hash algorithm(derived from the Hash Algorithm
//Indicator) to the result of the concatenation of the previous step to
//produce the hash result.
byte[] dataForHash = sdad.Concat(hashList.SelectMany(x => x).ToArray());
byte[] hash = SHA1.Create().ComputeHash(dataForHash);
//7.Compare the calculated hash result from the previous step with the
//recovered Hash Result.If they are not the same, DDA has failed.
if (Formatting.ByteArrayToHexString(sdad.HashResult) != Formatting.ByteArrayToHexString(hash))
{
return(null);
}
return(iccDD);
}
public static ICCDynamicData VerifySDAD(ICCDynamicDataType iccDDType, bool isFirstGenAC, KernelDatabaseBase database, StaticDataToBeAuthenticatedList staticDataToBeAuthenticated, CAPublicKeyCertificate caPublicKey, CardResponse genACCardResponse)
{
EMVGenerateACResponse genAcResponse = (genACCardResponse.ApduResponse as EMVGenerateACResponse);
//section 6.6.2 of EMV book 2 - CDA
//1.If the Signed Dynamic Application Data has a length different from the
//length of the ICC Public Key Modulus, CDA has failed
byte[] sdadRaw = genAcResponse.SignedDynamicApplicationData.Value;
IssuerPublicKeyCertificate ipk = IssuerPublicKeyCertificate.BuildAndValidatePublicKey(database, caPublicKey.Modulus, caPublicKey.Exponent);
if (ipk == null)
{
return(null);
}
IccPublicKeyCertificate iccpk = IccPublicKeyCertificate.BuildAndValidatePublicKey(database, staticDataToBeAuthenticated, ipk.Modulus, ipk.Exponent);
if (iccpk == null)
{
return(null);
}
if (sdadRaw.Length != iccpk.Modulus.Length)
{
return(null);
}
//2.To obtain the recovered data specified in Table 22, apply the recovery
//function as specified in Annex A2.1 on the Signed Dynamic Application
//Data using the ICC Public Key in conjunction with the corresponding
//algorithm.If the Recovered Data Trailer is not equal to 'BC', CDA has
//failed
byte[] decrypted = PublicKeyCertificate.DecryptRSA(sdadRaw, iccpk.Modulus, iccpk.Exponent);
SDAD sdad = new SDAD(decrypted);
//3.Check the Recovered Data Header. If it is not '6A', CDA has failed.
if (sdad.DataHeader != 0x6A)
{
return(null);
}
//4.Check the Signed Data Format. If it is not '05', CDA has failed.
if (sdad.SignedDataFormat != 0x05)
{
return(null);
}
//5. Retrieve from the ICC Dynamic Data the data specified in Table 19
ICCDynamicData iccDD = new ICCDynamicData(database, sdad.ICCDynamicData, iccDDType);
//6.Check that the Cryptogram Information Data retrieved from the ICC
//Dynamic Data is equal to the Cryptogram Information Data obtained from
//the response to the GENERATE AC command. If this is not the case, CDA
//has failed.
if (genAcResponse.CryptogramInformationData.Value[0] != iccDD.CryptogramInformationData)
{
return(null);
}
//7.Concatenate from left to right the second to the sixth data elements in
//Table 22(that is, Signed Data Format through Pad Pattern), followed by
//the Unpredictable Number.
byte[] unpredicatbleNumber = database.Get(EMVTagsEnum.UNPREDICTABLE_NUMBER_9F37_KRN).Value;
byte[] dataForHash = sdad.Concat(unpredicatbleNumber);
//8.Apply the indicated hash algorithm (derived from the Hash Algorithm
//Indicator) to the result of the concatenation of the previous step to
//produce the hash result.
byte[] hash = SHA1.Create().ComputeHash(dataForHash);
//9.Compare the calculated hash result from the previous step with the
//recovered Hash Result.If they are not the same, CDA has failed.
if (Formatting.ByteArrayToHexString(sdad.HashResult) != Formatting.ByteArrayToHexString(hash))
{
return(null);
}
//10. Concatenate from left to right the values of the following data elements:
List <byte[]> result = new List <byte[]>();
if (isFirstGenAC)
{
//-The values of the data elements specified by, and in the order they
//appear in the PDOL, and sent by the terminal in the GET
//PROCESSING OPTIONS command.
result.Add(database.Get(EMVTagsEnum.PDOL_RELATED_DATA_DF8111_KRN2).Value);
//-The values of the data elements specified by, and in the order they
//appear in the CDOL1, and sent by the terminal in the first
//GENERATE AC command.
result.Add(database.Get(EMVTagsEnum.CDOL1_RELATED_DATA_DF8107_KRN2).Value);
//-The tags, lengths, and values of the data elements returned by the ICC
//in the response to the GENERATE AC command in the order they are
//returned, with the exception of the Signed Dynamic Application Data.
foreach (TLV tlv in genAcResponse.GetResponseTags())
{
if (tlv.Tag.TagLable != EMVTagsEnum.SIGNED_DYNAMIC_APPLICATION_DATA_9F4B_KRN.Tag)
{
result.Add(tlv.Serialize());
}
}
}
else
{
//-The values of the data elements specified by, and in the order they
//appear in the PDOL, and sent by the terminal in the GET
//PROCESSING OPTIONS command.
result.Add(database.Get(EMVTagsEnum.PDOL_RELATED_DATA_DF8111_KRN2).Value);
//-The values of the data elements specified by, and in the order they
//appear in the CDOL1, and sent by the terminal in the first
//GENERATE AC command.
result.Add(database.Get(EMVTagsEnum.CDOL1_RELATED_DATA_DF8107_KRN2).Value);
//-The values of the data elements specified by, and in the order they
//appear in the CDOL2, and sent by the terminal in the second
//GENERATE AC command.
TLV cdol2 = database.Get(EMVTagsEnum.CARD_RISK_MANAGEMENT_DATA_OBJECT_LIST_2_CDOL2_8D_KRN);
if (cdol2 != null)
{
result.Add(CommonRoutines.PackRelatedDataTag(database, cdol2));
}
//-The tags, lengths, and values of the data elements returned by the ICC
//in the response to the GENERATE AC command in the order they are
//returned, with the exception of the Signed Dynamic Application Data.
foreach (TLV tlv in genAcResponse.GetResponseTags())
{
if (tlv.Tag.TagLable != EMVTagsEnum.SIGNED_DYNAMIC_APPLICATION_DATA_9F4B_KRN.Tag)
{
result.Add(tlv.Serialize());
}
}
}
byte[] transactionHashData = result.SelectMany(a => a).ToArray();
//11.Apply the indicated hash algorithm (derived from the Hash Algorithm
//Indicator) to the result of the concatenation of the previous step to
//produce the Transaction Data Hash Code.
byte[] transactionHash = SHA1.Create().ComputeHash(transactionHashData);
//12.Compare the calculated Transaction Data Hash Code from the previous
//step with the Transaction Data Hash Code retrieved from the ICC
//Dynamic Data in Step 5.If they are not the same, CDA has failed.
if (Formatting.ByteArrayToHexString(iccDD.TransactionDataHashCode) != Formatting.ByteArrayToHexString(transactionHash))
{
return(null);
}
return(iccDD);
}
internal static IssuerPublicKeyCertificate BuildAndValidatePublicKey(KernelDatabaseBase database, byte[] caPublicKeyModulus, byte[] caPublicKeyExponent)
{
//section 6.3 EMV 4.3 Book 2
TLV issuerPublicKeyCertificate = database.Get(EMVTagsEnum.ISSUER_PUBLIC_KEY_CERTIFICATE_90_KRN);
TLV issuerPublicKeyExponent = database.Get(EMVTagsEnum.ISSUER_PUBLIC_KEY_EXPONENT_9F32_KRN);
TLV issuerPublicKeyRemainder = database.Get(EMVTagsEnum.ISSUER_PUBLIC_KEY_REMAINDER_92_KRN);
if (issuerPublicKeyCertificate.Value.Length != caPublicKeyModulus.Length)
{
return(null);
}
byte[] decrypt = DecryptRSA(issuerPublicKeyCertificate.Value, caPublicKeyModulus, caPublicKeyExponent);
IssuerPublicKeyCertificate issuerCertData = new IssuerPublicKeyCertificate(decrypt, caPublicKeyModulus.Length,
issuerPublicKeyRemainder == null ? new byte[0] : issuerPublicKeyRemainder.Value, issuerPublicKeyExponent.Value);
if (issuerCertData.RecoveredDataTrailer != 0xBC)
{
return(null);
}
if (issuerCertData.RecoveredDataHeader != 0x6A)
{
return(null);
}
if (issuerCertData.CertificateFormat != 0x02)
{
return(null);
}
if (!issuerCertData.ValidateHash())
{
return(null);
}
string pan = Formatting.ByteArrayToHexString(database.Get(EMVTagsEnum.APPLICATION_PRIMARY_ACCOUNT_NUMBER_PAN_5A_KRN).Value);
string issuerIdentifier = Formatting.ByteArrayToHexString(issuerCertData.IssuerIdentifier).Replace("FF", "");
if (!pan.StartsWith(issuerIdentifier))
{
return(null);
}
DateTime expiry = DateTime.ParseExact(Formatting.BcdToString(issuerCertData.ExpiryDate), "MMyy", System.Globalization.CultureInfo.InvariantCulture);
//TODO: if you have a test tool trying to use an expired cert then comment this test out or update your test tool
//if (expiry <= DateTime.Now)
//{
// Logger.Log("Error: Trying to use an expired issuer public key");
// return null;
//}
//step 10 optional
if (issuerCertData.PublicKeyAlgorithmIndicator != 0x01)
{
return(null);
}
if (issuerPublicKeyRemainder != null)
{
issuerCertData.Modulus = Formatting.ConcatArrays(issuerCertData.UnpaddedIssuerPublicKeyorLeftmostDigitsofIssuerPublicKey, issuerPublicKeyRemainder.Value);
}
else
{
issuerCertData.Modulus = issuerCertData.UnpaddedIssuerPublicKeyorLeftmostDigitsofIssuerPublicKey;
}
return(issuerCertData);
}