Hi all, I have created "Decrypt" function If I put in function a string pass ... like ... Decrypt("asd4as5da6a<6asd/?") ... it return correct password BUT if I read from database and put this into this function ... like ... Decrypt(dr[1].ToString()) ... it return nothing ... blank text ... I am sure from database I read a string ... there is something ... because I tried to read this encrypted text ... It appear ... but when I use this decrypt function .. problem so I dont understand Can someone help me? Thank you!

Hi @ Takeshi , Welcome to Microsoft Q&A, Updated: It store diffent encrypter string to second database. Solve the problem of character changes. When reading strings from the database, make sure to use the correct character encoding. If different character encodings are used between the database and application, string parsing errors may result. You can use the Encoding class to explicitly specify the character encoding. Before passing the string to the decryption function, sanitize it to ensure that no extra whitespace characters or special characters interfere with the decryption process. You can use the Trim() method to remove whitespace characters from both ends of a string. Best Regards, Jiale If the answer is the right solution, please click " Accept Answer " and kindly upvote it. If you have extra questions about this answer, please click " Comment ". Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

If this is SQL-Server check out Passwords in SQL-Server C#

How to decrypt password from database?

Takeshi 41

Hi all,

I have created "Decrypt" function
If I put in function a string pass ... like ... Decrypt("asd4as5da6a<6asd/?") ... it return correct password
BUT if I read from database and put this into this function ... like ... Decrypt(dr[1].ToString()) ... it return nothing ... blank text ... I am sure from database I read a string ... there is something ... because I tried to read this encrypted text ... It appear ... but when I use this decrypt function .. problem
so I dont understand
Can someone help me?

Thank you!

Takeshi 41

This is that Decrypt function ...

public string DecryptString(string cipherText)
{
    byte[] iv = new byte[16];
    byte[] buffer = Convert.FromBase64String(cipherText);

    using (Aes aes = Aes.Create())
    {
        aes.Key = Encoding.UTF8.GetBytes(key);
        aes.IV = iv;
        ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

        using (MemoryStream memoryStream = new MemoryStream(buffer))
        {
            using (CryptoStream cryptoStream = new CryptoStream((Stream)memoryStream, decryptor, CryptoStreamMode.Read))
            {
                using (StreamReader streamReader = new StreamReader((Stream)cryptoStream))
                {
                    return streamReader.ReadToEnd();
                }
            }
        }
    }
}

Viorel 114.7K Reputation points

2024-03-12T09:12:01.06+00:00

Maybe the dr[1].ToString() is not "asd4as5da6a<6asd/?", or contains some additional whitespaces.

(By the way, Convert.FromBase64String does not seem to work with "asd4as5da6a<6asd/?" if this was a real example).
Takeshi 41 Reputation points

2024-03-12T14:57:23+00:00
OK ... this is a real string ... "YiEcbPHrfIy74+n0IaoMCg=="

dr[1].ToString() is exactly same as a string ... I tried to read it from database (without decrypt) ... so I know
dr[1].ToString() =

I also tried to copy this string from database manually (ctrl + c) and paste that string into decrypt function ... it works ...
Decrypt("

BUT this not work ... gives no string ...
Decrypt(dr["heslo"].ToString().Trim())
Viorel 114.7K Reputation points

2024-03-12T15:45:18.09+00:00

Try to debug the code step-by-step in case of constant DecryptString("YiEcbPHrfIy74+n0IaoMCg=="). Then execute DecryptString(dr["heslo"].ToString().Trim()), examine the variables and find the differences.

2 answers

Jiale Xue - MSFT 43,046 Reputation points Microsoft Vendor

2024-03-12T13:29:09.0966667+00:00

Hi @Takeshi , Welcome to Microsoft Q&A,

Updated: It store diffent encrypter string to second database.

Solve the problem of character changes.

When reading strings from the database, make sure to use the correct character encoding. If different character encodings are used between the database and application, string parsing errors may result. You can use the Encoding class to explicitly specify the character encoding.

Before passing the string to the decryption function, sanitize it to ensure that no extra whitespace characters or special characters interfere with the decryption process. You can use the Trim() method to remove whitespace characters from both ends of a string.

Best Regards,

Jiale

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Please sign in to rate this answer.
Takeshi 41 Reputation points

2024-03-12T15:03:08.01+00:00

Soory ... there is problem on the anoter place ... not in decrypt function ... I am still looking for ...

... I just coppy this encrypt string to database and it wordks... no idea for now ... I let you know

Jiale Xue - MSFT 43,046 Reputation points Microsoft Vendor

2024-03-12T15:37:13.96+00:00

Is your problem solved? Did the special characters change when you copied it to the database and then took it out? Have you confirmed it?

Takeshi 41 Reputation points

2024-03-12T15:42:14.9133333+00:00

I find that problem ... I dont know how it is possible, but it seems that it store diffent encrypter string to second database

Jiale Xue - MSFT 43,046 Reputation points Microsoft Vendor

2024-03-13T14:37:22.4766667+00:00

Hi @Takeshi , Glad you found the exact problem and I've turned it into an answer. If it solves your problem, you can mark it as the answer to help others.
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Karen Payne MVP 35,386 Reputation points

2024-03-13T23:20:23.5733333+00:00

If this is SQL-Server check out Passwords in SQL-Server C#
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How to decrypt password from database?

2 answers