wp_validate_auth_cookie()

wp_validate_auth_cookie() — Validates authentication cookie. The checks include making sure that the authentication cookie is set and pulling in the contents (if $cookie is not used). Makes sure the cookie is not expired. Verifies the hash in cookie is what is should be and compares the two.

Inputs: $cookie (string): Optional. If used, will validate contents instead of cookie’s. $scheme (string): Optional. The cookie scheme to use: ‘auth’, ‘secure_auth’, or ‘logged_in’. Note: This does *not* default to ‘auth’ like other cookie functions.

Returns int|false: User ID if valid cookie, false if invalid.