Вот пример того, как сгенерировать master key
из репозитория github.
private static string GenerateMasterKeyAuthorizationSignature(string verb, string resourceId, string resourceType, string key, string keyType, string tokenVersion)
{
var hmacSha256 = new System.Security.Cryptography.HMACSHA256 { Key = Convert.FromBase64String(key) };
string payLoad = string.Format(System.Globalization.CultureInfo.InvariantCulture, "{0}\n{1}\n{2}\n{3}\n{4}\n",
verb.ToLowerInvariant(),
resourceType.ToLowerInvariant(),
resourceId,
utc_date.ToLowerInvariant(),
""
);
byte[] hashPayLoad = hmacSha256.ComputeHash(System.Text.Encoding.UTF8.GetBytes(payLoad));
string signature = Convert.ToBase64String(hashPayLoad);
return System.Web.HttpUtility.UrlEncode(String.Format(System.Globalization.CultureInfo.InvariantCulture, "type={0}&ver={1}&sig={2}",
keyType,
tokenVersion,
signature));
}