Generates a random string of a specified length. Defaults to 25 characters.

GetRandomString.cs

/// <summary>
/// Gets a random crypto string
/// </summary>
/// <param name="length">The length of the string to generate</param>
/// <remarks>Typically the length is 25</remarks>
/// <returns>Returns a random string of characters of length size.</returns>
public static string GetRandomString(int length = 25)
{
    // Set the character space
    string allowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

    using (RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider()) {
        byte[] randomBytes = new byte[length];
        char[] randomChars = new char[length];

        rng.GetBytes(randomBytes);

        for (int i = 0; i < length; i++) {
            randomChars[i] = allowedChars[(int)randomBytes[i] % allowedChars.Length];
        }

        return new string(randomChars);
    }
}