Here are the relevant laws regarding the leaking and transmission of classified United States documents. 

18 U.S. Code § 798 - Disclosure of classified information
https://www.law.cornell.edu/uscode/text/18/798

(a) Whoever knowingly and willfully communicates, furnishes, transmits, or otherwise makes available to an unauthorized person, or publishes, or uses in any manner prejudicial to the safety or interest of the United States or for the benefit of any foreign government to the detriment of the United States any classified information—
(1) concerning the nature, preparation, or use of any code, cipher, or cryptographic system of the United States or any foreign government; or
(2) concerning the design, construction, use, maintenance, or repair of any device, apparatus, or appliance used or prepared or planned for use by the United States or any foreign government for cryptographic or communication intelligence purposes; or
(3) concerning the communication intelligence activities of the United States or any foreign government; or
(4) obtained by the processes of communication intelligence from the communications of any foreign government, knowing the same to have been obtained by such processes—
Shall be fined under this title or imprisoned not more than ten years, or both.

18 U.S. Code § 793 - Gathering, transmitting or losing defense information
https://www.law.cornell.edu/uscode/text/18/793

(e) Whoever having unauthorized possession of, access to, or control over any document, writing, code book, signal book, sketch, photograph, photographic negative, blueprint, plan, map, model, instrument, appliance, or note relating to the national defense, or information relating to the national defense  which information the possessor has reason to believe could be used to the injury of the United States or to the advantage of any foreign nation, willfully communicates, delivers, transmits or causes to be communicated, delivered, or transmitted, or attempts to communicate, deliver, transmit or cause to be communicated, delivered, or transmitted the same to any person not entitled to receive it, or willfully retains the same and fails to deliver it to the officer or employee of the United States entitled to receive it; or
...
(1) Any person convicted of a violation of this section shall forfeit to the 'United States, irrespective of any provision of State law, any property constituting, or derived from, any proceeds the person obtained, directly or indirectly, from any foreign government, or any faction or party or military or naval force within a foreign country, whether recognized or unrecognized by the United States, as the result of such violation. For the purposes of this subsection, the term “State” includes a State of the United States, the District of Columbia, and any commonwealth, territory, or possession of the United States.
(2) The court, in imposing sentence on a defendant for a conviction of a violation of this section, shall order that  the defendant forfeit to the United States all property described in paragraph (1) of this subsection.