
1979 (Door) – Door Code at the start of the mission (shown on the poster directly left of the door).Crystal means 15 years and 2021 – 15 = 2006 which is the code.
They mention the code is the wedding year of the Yateses. Upstairs in their villa you can find a calendar on the wall from the year 2021 which has their wedding anniversary circled as “Crystal Anniversary”.
You’d normally find out the code by overhearing two guards outside the Yateses Villa by the cliffside.
2006 (Safe, Villa Basement) – Safe Code for the Villa Basement, contains important Intel and completes a Challenge. A guard talking to the Sommelier also says the code “is the last year of World War II”. The code is the same as the year the wine was mode, which is the year 1945 Grand Paladin. 1945 (Laser System) – Door Code to shut off the Laser System to the Wine Fridge on Floor Level 01 (Wine Cellar where the Sommelier is). This also completes Discovery Challenge “Quite a Hatch”. Enter code 2552 to unlock the secret hatch. 2552 (Secret Hatch) – In the fenced area behind the Arcade are two Street Guards and a keypad on a wall (Floor Level 00). 2552 (Door, Arcade) – Door Code inside the Arcade on Floor Level 00. 2552 (Door, Hush’s Private Lab) – Door Code to Therapy Room which you access by going to the balcony from Hush’s Private Lab. You can find this out by looking at a whiteboard on the same floor, behind a wall where Royce likes to stand around near a patient in a chair. You can find this out by looking at a whiteboard on the top floor (5th floor) of the same building. 2552 (Door, Benchmark Lab) – Door Code to the staircase in the Benchmark Lab, Floor Level 04 (building where “Hush”, the mission target is). Leads to the roof for All-Seeing Eyes Story. 0118 (Door, Laundromat) – Door Code in the Laundromat, on Floor Level 01. Same code combination as the Container Entrance to ICA Facility. You can find out this code by climbing into the same apartment from the roof and listening to the answering machine. 0118 (Door, ICA Apartment) – Door Code to the ICA Apartment that contains the P41 Form, on Floor Level 02 of an apartment building. Same code combination as the apartment with the P41 form. You can find this out by overhearing some people in front of the container talking about it and one of them will also enter the code to enter the facility and say it out loud. 0118 (Door, Container) – Container Door Code to the ICA Facility Entrance. You get the code by overhearing two employees talking and saying the code is the same year the Berlin wall was taken down (which was in year 1989) – thanks to Osiris for sharing this in the comments. 1989 (Safe, Hirschmüller’s Office) – Safe Code for Floor -02 Hirschmüller’s Office, contains Cocaine Brick and Gold Idol bust. The code is always the same so you can skip all that and enter it directly. You’d normally find out this code by looking at the 4 symbols above the safe (Clock, Telescope, Fire, Moose) and finding these objects around the manor which have numbers on the walls next to them. Press the button on her office chair and it will reveal a safe behind a picture frame. 1975 (Safe, Case File) – Safe Code containing the Case File. The code is on a blue sticky note on the computer screen in the same room ( Thanks to Angelweaver for sharing this in the comments). 7465 (Safe, Penthouse Guest Bedroom) – Safe in the Guest Bedroom in the Penthouse, Floor Level 05. Contains Evacuation Keycard that you can use on two panels in the Penthouse 5th & 4th floor to trigger the evacuation sequence of the two targets. 6927 (Safe, Security Room Floor 03) – Safe Code Floor Level 03, Security Room. Contains Evacuation Keycard that you can use on two panels in the Penthouse 5th & 4th floor to trigger the evacuation sequence of the two targets. 6927 (Safe, Security Room Floor 02) – Safe Code Floor Level 02, Security Room. You can see the code on a whiteboard in the Meeting Room on Floor Level 00. This is the door in the bottom map corner of the Atrium (same code as the other door). 4706 (Door, Atrium) – Door Code between Atrium and Staff Area on Floor Level 00. You can see the code on a whiteboard in the Meeting Room on Floor Level 00. 4706 (Door, Staff Area) – Door Code to Staff Area on Floor Level 00 which you can enter from the Atrium (behind the bar).