Penal Code § 2541
ARTICLE 6. Prohibition Upon Wardens, Clerks, Officers and Employees
No officer or employee of the department, or contractor, or employee of a contractor, shall, without permission of the director, make any gift or present to a prisoner, or receive any from a prisoner, or have any barter or dealings with a prisoner. For every violation of the provisions of this section, the party engaged therein shall incur the same penalty as prescribed in the preceding section. No officer or employee of the prison shall be interested, directly or indirectly, in any contract or purchase made or authorized to be made by anyone for or on behalf of the prisons.