C#: SHA1 String Hash Extension Method

In a recent project I needed the ability to take an incoming string value and calculate its SHA1 Hash in order to tell if the value had been altered in some way. Instead of creating a special utility class to accomplish this I figured a clean solution would be to just add an extension method to the String class. Here is what I came up with.

        /// Calculates the SHA1 hash and returns it as a base64 string.
        /// Source string to hash
        /// Base64 Hash or null.
        /// Occurs when value or key is null or empty.
        public static string GetSha1Hash(this string value)
            if (string.IsNullOrEmpty(value))
                throw new ArgumentException("String is empty and not hashable.");
            Byte[] bytes = Encoding.UTF8.GetBytes(value);
            Byte[] computedHash = new SHA1CryptoServiceProvider().ComputeHash(bytes);
            return Convert.ToBase64String(computedHash);

Published by

Tim Clark

Experienced Business Owner, Chief Information Officer, Vice President, Chief Software Architect, Application Architect, Project Manager, Software Developer, Senior Web Developer, Graphic Designer & 3D Modeler, University Instructor, University Program Chair, Academic Director. Specialties: Ruby, Ruby on Rails, JavaScript, JQuery, AJAX, Node.js, React.js, Angular.js, MySQL, PostgreSQL, MongoDB, SQL Server, Responsive Design, HTML5, XHTML, CSS3, C#, ASP.net, Project Management, System Design/Architecture, Web Design, Web Development, Adobe CS6 (Photoshop, Illustrator)

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