Methods and systems for javascript parsing

• US 9,639,519 B1
• Filed: 12/16/2015
• Issued: 05/02/2017
• Est. Priority Date: 07/12/2007
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Sebastian, William B.
• Primary Examiner(s): Eskandarnia, Arvin
• Application Number:
  US14/972,025
• Time in Patent Office: 503 Days
• CPC Class Codes: G06F 16/9566 URL specific, e.g. using aliases, detecting broken or misspelled links
• CPC Class Codes: G06F 16/986 Document structures and storage, e.g. HTML extensions
• CPC Class Codes: G06F 40/134 Hyperlinking
• CPC Class Codes: G06F 40/143 Markup, e.g. Standard Generalized Markup Language [SGML] or Document Type Definition [DTD]
• CPC Class Codes: G06F 40/205 Parsing
• CPC Class Codes: G06F 40/211 Syntactic parsing, e.g. based on context-free grammar [CFG] or unification grammars
• CPC Class Codes: G06F 40/221 Parsing markup language streams streaming G06F40/149
• CPC Class Codes: G06F 40/242 Dictionaries
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 9/3213 using tickets or tokens, e.g. Kerberos network architectures or network communication protocols for entities authentication using tickets in a packet data network H04L63/0807

Abstract

The present invention relates to systems, apparatus, and methods of parsing a script within an HTML page. The method includes receiving a script object, where the script object includes text. The method further includes parsing the text of the script object for tokens and comparing the parsed tokens with a valid tokens list to determine locations within the text of the script object that include potential universal resource locators (URLs). The method includes parsing before and after the determined locations until complete URLs are constructed, and forwarding the complete URLs to a detector. The detector then determines whether the complete URLs are valid. The method then sends object retrieval requests to websites associated with the valid complete URLs.

Claims

1. An apparatus for scanning an executable script object comprising:

a digital dictionary configured to store tokens each comprising a possible piece of a uniform resource locator (URL);

a script parser configured to;

receive an executable script object comprising text,

parse the text of the executable script object to find an instance of one of the tokens in the text,

continue to parse the text of the executable script object adjacent to the instance of the token to find a syntax element, and

construct a candidate URL from the instance of the token and the syntax element;

a URL rules detector configured to;

store rules for validating URLs, and

utilize the stored rules to determine whether the candidate URL is a valid URL.

2. The apparatus of claim 1, wherein the script parser is further configured to continue to parse the text of the executable script object backwards and forwards from the instance of the token to find the syntax element and an instance of another of the tokens.

3. The apparatus of claim 2, wherein the script parser is further configured to construct the candidate URL from the instance of the token, the instance of the another of the tokens, and the syntax element.

4. The apparatus of claim 3, wherein:

the instance of the token is a first text string in the executable script object,

the instance of the another of the tokens is a second text string in the executable script object, and

the syntax element is a combine operator.

5. The apparatus of claim 4, wherein the candidate URL comprises the first text string concatenated to the second text string.

6. The apparatus of claim 1, wherein the script parser is further configured to parse and continue to parse the text of the executable script object without executing the script.

7. The apparatus of claim 6, wherein the script parser is further configured to construct the candidate URL without executing the script.

8. The apparatus of claim 1, wherein the tokens stored in the digital dictionary include different file type identifiers.

9. The apparatus of claim 8, wherein the different file type identifiers include a joint photographic experts group (JPEG) file type identifier and a graphics interchange format (GIF) file type identifier.

10. The apparatus of claim 1, wherein the syntax elements stored in the digital dictionary include operators.

11. The apparatus of claim 10, wherein the operators include a combine operator “

+”

.

12. The apparatus of claim 1, wherein:

the digital dictionary is further configured to store syntax elements for constructing complete URLs from the tokens, and

the syntax element the script parser is configured to fine is one of the stored syntax elements.

13. The apparatus of claim 12, wherein:

the executable script object corresponds to a script language comprising operators and expressions, and

the syntax stored in the digital dictionary comprises the operators and expressions of the script language.

14. The apparatus of claim 13, wherein the script language is JavaScript.

15. The apparatus of claim 14, wherein the executable script object is part of a hypertext markup language (HTML) page.

16. The apparatus of claim 1, wherein the URL rules detector is further configured to send an object retrieval request to a Website associated with the candidate URL if the candidate URL is a valid URL.

17. The apparatus of claim 16, wherein the URL rules detector is further configured to send the object retrieval request over a communications link to a server device.

18. The apparatus of claim 17, wherein the communications link comprises a satellite link.

19. The apparatus of claim 16, wherein:

the digital dictionary, script parser, and URL rules detector are elements of a proxy server configured to intercept content served by a server device, and

the executable script object is part of content served by the server device.

20. The apparatus of claim 19, wherein the content served by the server device comprises a hypertext markup language (HTML) page.