CODEWITHSUNDEEP
c#
Gerald Hendrix
Gerald Hendrix

Reputation: 43

Trying to pass a Base64 string as a Byte

Please help. I need to pass 3 values to a webservice:

This PassHash is what's giving me the problem, because PassHash is supposed to be the UserID and Password concatenated together(UserIDPassword), then calculating a binary MD5 hash of this value, then converting this hash value to a Base64 decoded string. My C# code below shows an example of what I have so far. 

protected void btnSubmit_Click(object sender, EventArgs e) {
    string UnameVal = "BSimpson";
    string PwordVal = "Springfield";
    string ReportDate = "2015-12-25";
    string source = string.Concat(UnameVal, PwordVal);
    string hashed = getMd5Hash2(source);
    byte[] ph1 = System.Text.Encoding.UTF8.GetBytes(hashed);

//Build Hyperlink...
         var sb = new StringBuilder();
 sb.AppendFormat("https://ExampleService/GetRptLength?ReportDate={0}&UserID={1}&PassHash={2}", ReportDate, UnameVal, ph1);
     HyperLink1.Visible = true;
     HyperLink1.NavigateUrl = sb.ToString();
}

static string getMd5Hash2(string input) {
    // Create a new instance of the MD5CryptoServiceProvider object.
    MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();

    // Convert the input string to a byte array and compute the hash.
    byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));

    // Create a new Stringbuilder to collect the bytes
    // and create a string.
    StringBuilder sBuilder = new StringBuilder();

    // Loop through each byte of the hashed data 
    // and format each one as a hexadecimal string.
    for (int i = 0; i < data.Length; i++) {
        sBuilder.Append(data[i].ToString("x2"));
    }

    // Return the hexadecimal string.
    return sBuilder.ToString();
}

Here is the result of building the hyperlink.

When I submit this link, it states that I have an "Invalid Password Hash Value". Isn't there supposed to be a value for PassHash instead of just System.Byte[]? What am I doing wrong here?

Upvotes: 2

Views: 661

Answers (1)

Jonathon Chase
Jonathon Chase

Reputation: 9704

You'll need to take your byte array and convert it to a base64 string, as a byte array won't have a valid representation given by it's .ToString() method.

You can do this with the following:

var passwordHashInBase64 = System.Convert.ToBase64String(ph1);

Then just pass the passwordHashInBase64 to your string builder instead of ph1.

Edit:

Looking more closely at your code, it seems like you're taking an extra step in general here. In your getMd5Hash2 function, after this line:

byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));

add return System.Convert.ToBase64String(data);

and remove the stringbuilder/hexadecimal representation.

Then, in your submit event, don't worry about getting the bytes from hashed and just pass in that string as your hash value.

sb.AppendFormat("https://ExampleService/GetRptLength?ReportDate={0}&UserID={1}&PassHash={2}", ReportDate, UnameVal, hashed);

Upvotes: 1

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