diff --git a/lib/hyde/util/cookie.rb b/lib/hyde/util/cookie.rb
new file mode 100644
index 0000000..b7ece50
--- /dev/null
+++ b/lib/hyde/util/cookie.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require_relative 'header'
+
+module Hyde
+  # Utility class for handling cookies
+  class Cookie
+    # @param data [String] raw cookie data
+    def initialize(key, value, params = {})
+      @key = key
+      @value = value
+      @params = params
+    end
+
+    # Convert cookie to "Set-Cookie: " string representation.
+    # @return [String]
+    def to_s
+      Hyde::Util.make_value(to_short, @params)
+    end
+
+    # Convert cookie to "Cookie: " string representation (no params)
+    def to_short
+      "#{key.to_s.strip}=#{value.to_s.strip}"
+    end
+
+    attr_accessor :key, :value
+    attr_reader :params
+
+    # Create cookie from a "Set-Cookie: " format
+    # @param data [String] value part of "Set-Cookie: " header
+    # @return [Cookie]
+    def self.from_setcookie_string(data)
+      kvpair, params = Hyde::Util.parse_value(data)
+      key, value = kvpair.split("=").map(&:strip)
+      Cookie.new(key, value, params)
+    end
+
+    # Create cookie(s) from a "Cookie: " format
+    # @param data [String] value part of "Cookie: " header
+    # @return [Array(Cookie)]
+    def self.from_cookie_string(data)
+      data.split(";").map do |cookiestr|
+        Cookie.new(*cookiestr.split("=").map(&:strip))
+      end
+    end
+  end
+end
diff --git a/lib/hyde/util/header.rb b/lib/hyde/util/header.rb
index 54671c1..1e1a56c 100644
--- a/lib/hyde/util/header.rb
+++ b/lib/hyde/util/header.rb
@@ -12,7 +12,12 @@ module Hyde
       parts = input.split(sep).map { |x| URI.decode_uri_component(x).strip }
       base = parts.shift
       opts = parts.map do |raw|
-        key, value = raw.match(/^([^=]*)(?:=(.*)|)\Z/).to_a[1..]
+        key, value = raw.match(/
+            \A                    # beginning of string
+            ([!-~&&[^=;,]]+)      # key
+            (?:=([\s!-~&&[^;,]]*)|) # optional value
+            \Z                    # end of sting
+        /x).to_a[1..]
         [key, ((value&.match?(/^".*"$/) ? value[1..-2] : value) or true)]
       end.to_h
       [base, opts]
@@ -24,7 +29,7 @@ module Hyde
     # @return [String]
     def self.make_value(input, opts, sep = ";")
       unless input.match?(/^[\w!#$%&'*+-.^_`|~]*=?[^[:cntrl:]\\",;]+$/)
-        raise StandardError, "input contains invalid characters"
+        raise StandardError, "input format is invalid"
       end
 
       output = input