SHA-1 Hash a byte array vs a file stream

Question

I am writing an API that allows users to upload files (image, video, etc). I use a SHA-1 hash to make sure the same file isn't uploaded multiple times. Previously we only allowed smaller files so I was reading them into a byte array and hashing that but now we allow larger files so I am using a file stream. The problem is the SHA-1 algorithm returns a different hash. I need to figure out how to get the same hash regardless of the method, even if I have to turn the byte array into a file stream or something. However, I've tried writing the byte array to a temp file and reading it in and it returns the same hash as the byte array. Here is an example console app that shows what I am doing:

static void Main(string[] args)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test.png";
    var bytes = File.ReadAllBytes(file);
    using (var stream = File.Open(file, FileMode.Open))
    {
        Console.WriteLine(Sha1HashFile(bytes));   // Returns B7F6D90C30233F91FCEFE05FB49679F8B26C9D80
        Console.WriteLine(Sha1HashFile(stream));  // Returns DA39A3EE5E6B4B0D3255BFEF95601890AFD80709
        Console.WriteLine(Sha1HashFile2(bytes));  // Returns B7F6D90C30233F91FCEFE05FB49679F8B26C9D80
    }

    Console.Read();
}

public static string Sha1HashFile(byte[] file)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(file)).Replace("-", "");
    }
}

public static string Sha1HashFile(Stream stream)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(stream)).Replace("-", "");
    }
}

public static string Sha1HashFile2(byte[] bytes)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test2.png";
    File.WriteAllBytes(file, bytes);
    return Sha1HashFile(File.OpenRead(file));
}

I've even tried to just put the byte array into a MemoryStream with new MemoryStream(bytes) but that didn't work either. It seems like once I have the file in a byte array it can't be put back.

EDIT:

I removed some code from my example because I thought MD5 was working. Here is the original code I was using to test:

static void Main(string[] args)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test.png";
    var bytes = File.ReadAllBytes(file);
    using (var stream = File.Open(file, FileMode.Open))
    {
        Console.WriteLine(Md5HashFile(bytes));
        Console.WriteLine(Md5HashFile(stream));
        Console.WriteLine(Sha1HashFile(bytes));
        Console.WriteLine(Sha1HashFile(stream));
        Console.WriteLine(Sha1HashFile2(bytes));
    }

    Console.Read();
}

public static string Md5HashFile(byte[] file)
{
    using (MD5 md5 = MD5.Create())
    {
        return BitConverter.ToString(md5.ComputeHash(file)).Replace("-", "");
    }
}

public static string Sha1HashFile(byte[] file)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(file)).Replace("-", "");
    }
}

public static string Md5HashFile(Stream stream)
{
    using (MD5 md5 = MD5.Create())
    {
        return BitConverter.ToString(md5.ComputeHash(stream)).Replace("-", "");
    }
}

public static string Sha1HashFile(Stream stream)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(stream)).Replace("-", "");
    }
}

public static string Sha1HashFile2(byte[] bytes)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test2.png";
    File.WriteAllBytes(file, bytes);
    return Sha1HashFile(File.OpenRead(file));
}

See answer below for explanation of the problem.

Answer 1

The problem is that the stream is being read to the end when hashing the first way. That is causing the second hash to be wrong. Because of that, I need to either reopen a stream for the second hash or rewind the stream to the beginning before hashing the second way. Here is the solution:

static void Main(string[] args)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test.png";
    var bytes = File.ReadAllBytes(file);
    using (var stream = File.Open(file, FileMode.Open))
    {
        Console.WriteLine(Md5HashFile(bytes));
        Console.WriteLine(Md5HashFile(stream));
    }

    using (var stream = File.Open(file, FileMode.Open))
    {
        Console.WriteLine(Sha1HashFile(bytes));
        Console.WriteLine(Sha1HashFile(stream));
        Console.WriteLine(Sha1HashFile2(bytes));
    }

    Console.Read();
}

public static string Md5HashFile(byte[] file)
{
    using (MD5 md5 = MD5.Create())
    {
        return BitConverter.ToString(md5.ComputeHash(file)).Replace("-", "");
    }
}

public static string Sha1HashFile(byte[] file)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(file)).Replace("-", "");
    }
}

public static string Md5HashFile(Stream stream)
{
    using (MD5 md5 = MD5.Create())
    {
        return BitConverter.ToString(md5.ComputeHash(stream)).Replace("-", "");
    }
}

public static string Sha1HashFile(Stream stream)
{
    using (SHA1Managed sha1 = new SHA1Managed())
    {
        return BitConverter.ToString(sha1.ComputeHash(stream)).Replace("-", "");
    }
}

public static string Sha1HashFile2(byte[] bytes)
{
    string file = "C:\\CUWCDFileStorage\\temp\\test2.png";
    File.WriteAllBytes(file, bytes);
    return Sha1HashFile(File.OpenRead(file));
}