Decrypting the encoded password

Create a Encrypt & Decrypt method when you pass the string it will give you the value you required.

Save the Encrypted values in Database

usingSystem;
usingSystem.Text;
usingSystem.Security.Cryptography;
usingSystem.IO;
usingSystem.Linq;
namespaceEncryptStringSample
{
publicstaticclassStringCipher
{
//Thisconstantisusedtodeterminethekeysizeoftheencryptionalgorithminbits.
//Wedividethisby8withinthecodebelowtogettheequivalentnumberofbytes.
privateconstintKeysize=256;
//Thisconstantdeterminesthenumberofiterationsforthepasswordbytesgenerationfunction.
privateconstintDerivationIterations=1000;
publicstaticstringEncrypt(stringplainText,stringpassPhrase)
{
//SaltandIVisrandomlygeneratedeachtime,butispreprendedtoencryptedciphertext
//sothatthesameSaltandIVvaluescanbeusedwhendecrypting.
varsaltStringBytes=Generate256BitsOfRandomEntropy();
varivStringBytes=Generate256BitsOfRandomEntropy();
varplainTextBytes=Encoding.UTF8.GetBytes(plainText);
using(varpassword=newRfc2898DeriveBytes(passPhrase,saltStringBytes,DerivationIterations))
{
varkeyBytes=password.GetBytes(Keysize/8);
using(varsymmetricKey=newRijndaelManaged())
{
symmetricKey.BlockSize=256;
symmetricKey.Mode=CipherMode.CBC;
symmetricKey.Padding=PaddingMode.PKCS7;
using(varencryptor=symmetricKey.CreateEncryptor(keyBytes,ivStringBytes))
{
using(varmemoryStream=newMemoryStream())
{
using(varcryptoStream=newCryptoStream(memoryStream,encryptor,CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes,0,plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
//Createthefinalbytesasaconcatenationoftherandomsaltbytes,therandomivbytesandthecipherbytes.
varcipherTextBytes=saltStringBytes;
cipherTextBytes=cipherTextBytes.Concat(ivStringBytes).ToArray();
cipherTextBytes=cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
memoryStream.Close();
cryptoStream.Close();
returnConvert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
publicstaticstringDecrypt(stringcipherText,stringpassPhrase)
{
//Getthecompletestreamofbytesthatrepresent:
//[32bytesofSalt]+[32bytesofIV]+[nbytesofCipherText]
varcipherTextBytesWithSaltAndIv=Convert.FromBase64String(cipherText);
//Getthesaltbytesbyextractingthefirst32bytesfromthesuppliedcipherTextbytes.
varsaltStringBytes=cipherTextBytesWithSaltAndIv.Take(Keysize/8).ToArray();
//GettheIVbytesbyextractingthenext32bytesfromthesuppliedcipherTextbytes.
varivStringBytes=cipherTextBytesWithSaltAndIv.Skip(Keysize/8).Take(Keysize/8).ToArray();
//Gettheactualciphertextbytesbyremovingthefirst64bytesfromthecipherTextstring.
varcipherTextBytes=cipherTextBytesWithSaltAndIv.Skip((Keysize/8)*2).Take(cipherTextBytesWithSaltAndIv.Length-((Keysize/8)*2)).ToArray();
using(varpassword=newRfc2898DeriveBytes(passPhrase,saltStringBytes,DerivationIterations))
{
varkeyBytes=password.GetBytes(Keysize/8);
using(varsymmetricKey=newRijndaelManaged())
{
symmetricKey.BlockSize=256;
symmetricKey.Mode=CipherMode.CBC;
symmetricKey.Padding=PaddingMode.PKCS7;
using(vardecryptor=symmetricKey.CreateDecryptor(keyBytes,ivStringBytes))
{
using(varmemoryStream=newMemoryStream(cipherTextBytes))
{
using(varcryptoStream=newCryptoStream(memoryStream,decryptor,CryptoStreamMode.Read))
{
varplainTextBytes=newbyte[cipherTextBytes.Length];
vardecryptedByteCount=cryptoStream.Read(plainTextBytes,0,plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
returnEncoding.UTF8.GetString(plainTextBytes,0,decryptedByteCount);
}
}
}
}
}
}
privatestaticbyte[]Generate256BitsOfRandomEntropy()
{
varrandomBytes=newbyte[32];//32Byteswillgiveus256bits.
using(varrngCsp=newRNGCryptoServiceProvider())
{
//Fillthearraywithcryptographicallysecurerandombytes.
rngCsp.GetBytes(randomBytes);
}
returnrandomBytes;
}
}
}

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Bhuvanesh Mohankumar10y ago
Create a Encrypt & Decrypt method when you pass the string it will give you the value you required.
Save the Encrypted values in Database
usingSystem;
usingSystem.Text;
usingSystem.Security.Cryptography;
usingSystem.IO;
usingSystem.Linq;
namespaceEncryptStringSample
{
publicstaticclassStringCipher
{
//Thisconstantisusedtodeterminethekeysizeoftheencryptionalgorithminbits.
//Wedividethisby8withinthecodebelowtogettheequivalentnumberofbytes.
privateconstintKeysize=256;
//Thisconstantdeterminesthenumberofiterationsforthepasswordbytesgenerationfunction.
privateconstintDerivationIterations=1000;
publicstaticstringEncrypt(stringplainText,stringpassPhrase)
{
//SaltandIVisrandomlygeneratedeachtime,butispreprendedtoencryptedciphertext
//sothatthesameSaltandIVvaluescanbeusedwhendecrypting.
varsaltStringBytes=Generate256BitsOfRandomEntropy();
varivStringBytes=Generate256BitsOfRandomEntropy();
varplainTextBytes=Encoding.UTF8.GetBytes(plainText);
using(varpassword=newRfc2898DeriveBytes(passPhrase,saltStringBytes,DerivationIterations))
{
varkeyBytes=password.GetBytes(Keysize/8);
using(varsymmetricKey=newRijndaelManaged())
{
symmetricKey.BlockSize=256;
symmetricKey.Mode=CipherMode.CBC;
symmetricKey.Padding=PaddingMode.PKCS7;
using(varencryptor=symmetricKey.CreateEncryptor(keyBytes,ivStringBytes))
{
using(varmemoryStream=newMemoryStream())
{
using(varcryptoStream=newCryptoStream(memoryStream,encryptor,CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes,0,plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
//Createthefinalbytesasaconcatenationoftherandomsaltbytes,therandomivbytesandthecipherbytes.
varcipherTextBytes=saltStringBytes;
cipherTextBytes=cipherTextBytes.Concat(ivStringBytes).ToArray();
cipherTextBytes=cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
memoryStream.Close();
cryptoStream.Close();
returnConvert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
publicstaticstringDecrypt(stringcipherText,stringpassPhrase)
{
//Getthecompletestreamofbytesthatrepresent:
//[32bytesofSalt]+[32bytesofIV]+[nbytesofCipherText]
varcipherTextBytesWithSaltAndIv=Convert.FromBase64String(cipherText);
//Getthesaltbytesbyextractingthefirst32bytesfromthesuppliedcipherTextbytes.
varsaltStringBytes=cipherTextBytesWithSaltAndIv.Take(Keysize/8).ToArray();
//GettheIVbytesbyextractingthenext32bytesfromthesuppliedcipherTextbytes.
varivStringBytes=cipherTextBytesWithSaltAndIv.Skip(Keysize/8).Take(Keysize/8).ToArray();
//Gettheactualciphertextbytesbyremovingthefirst64bytesfromthecipherTextstring.
varcipherTextBytes=cipherTextBytesWithSaltAndIv.Skip((Keysize/8)*2).Take(cipherTextBytesWithSaltAndIv.Length-((Keysize/8)*2)).ToArray();
using(varpassword=newRfc2898DeriveBytes(passPhrase,saltStringBytes,DerivationIterations))
{
varkeyBytes=password.GetBytes(Keysize/8);
using(varsymmetricKey=newRijndaelManaged())
{
symmetricKey.BlockSize=256;
symmetricKey.Mode=CipherMode.CBC;
symmetricKey.Padding=PaddingMode.PKCS7;
using(vardecryptor=symmetricKey.CreateDecryptor(keyBytes,ivStringBytes))
{
using(varmemoryStream=newMemoryStream(cipherTextBytes))
{
using(varcryptoStream=newCryptoStream(memoryStream,decryptor,CryptoStreamMode.Read))
{
varplainTextBytes=newbyte[cipherTextBytes.Length];
vardecryptedByteCount=cryptoStream.Read(plainTextBytes,0,plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
returnEncoding.UTF8.GetString(plainTextBytes,0,decryptedByteCount);
}
}
}
}
}
}
privatestaticbyte[]Generate256BitsOfRandomEntropy()
{
varrandomBytes=newbyte[32];//32Byteswillgiveus256bits.
using(varrngCsp=newRNGCryptoServiceProvider())
{
//Fillthearraywithcryptographicallysecurerandombytes.
rngCsp.GetBytes(randomBytes);
}
returnrandomBytes;
}
}
}
Mark as answer, if helpful.