Save byte array in sql server

If it's always going to be the same length, then binary(length) would be suitable. If it's going to vary in length, use varbinary(maxlength).

binary and varbinary.

And, as @p.s.w.g says, you pass it from code by placing it into a suitable parameter.

Just use a byte[] the same way you would any other parameter, specifying SqlDbType.Binary as the parameter type. Here a sample in C#

// Generate your password hash some way
byte[] passwordHash = new byte[] { 0x0, 0x1, 0x2 ... };

...

command.Parameters.Add("@passwordHash", SqlDbType.Binary);
command.Parameters["@passwordHash"].Value = passwordHash;

Or if you prefer VB.NET

' Generate your password hash some way
Dim passwordHash As Byte() = New Byte() { &H0, &H1, &H2 ... }

...

command.Parameters.Add("@passwordHash", SqlDbType.Binary)
command.Parameters("@passwordHash").Value = passwordHash