vault backup: 2022-08-05 15:29:10

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Jet Hughes 2022-08-05 15:29:10 +12:00
parent 4c2547eabe
commit 179580e721
10 changed files with 154 additions and 8 deletions

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@ -9,6 +9,16 @@ sr-interval: 3
sr-ease: 250
---
- [authorisation](notes/authorisation.md)
- [authentication](notes/authentication.md)
- [passwords](notes/passwords.md)
# Authentication
- proof of identity
- need to be sure a user is who they say they are before you can trust them

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@ -4,8 +4,8 @@ aliases:
tags:
- cosc204
- lecture
sr-due: 2022-08-04
sr-interval: 8
sr-due: 2022-08-24
sr-interval: 19
sr-ease: 250
---

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tags:
- lecture
- cosc204
sr-due: 2022-08-05
sr-interval: 7
sr-due: 2022-08-23
sr-interval: 18
sr-ease: 250
---
- [6809](notes/6809.md)
# Warnings
- different CPU architectures have their own machine codes and their own assembly languages
- assembly language programs are **not** portable across CPU architectures (e.g., 6809 to x86 ARM) but are often backwards compatible (e.g., x86_64 family)

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@ -4,8 +4,8 @@ aliases:
tags:
- lecture
- cosc204
sr-due: 2022-08-04
sr-interval: 3
sr-due: 2022-08-15
sr-interval: 10
sr-ease: 250
---

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---
title: "authentication"
aliases:
tags:
- comp210
---
# Authentication
- proof of identity
- need to be sure a user is who they say they are before you can trust them
- usually done via a unique identifier
- unique username
- and a secret that is only known by the authorised user
- password
- biometrics
- 2fa code
## MFA
- many secrets
- protects user/system in the case that a password is disclosed
- additional secrets generated at the time of use.
- short lived
- if found - attackers have a small windoe to exploit
- e.g.,
- sms message
- authenticator app

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---
title: "authorisation"
aliases:
tags:
- comp210
---
# Authorisation
- verifying that a user is allowed to access the operation that they are attempting to access
- requires explicit check in the system for restricted operatons
- some code that check if the roles assigned to the authenticaed user intersect the roles required for the current operation
- use is assigned a **role** that defines the operations they are allowed to perform
- e.g.
- custoemer - can view products, and see retail prices
- sales rep - can view products and see retail and cost prices
- manager - can add/delete/modify products
- admin - can change system configuration. can assign roles to users

62
content/notes/cmoc.md Normal file
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---
title: "cmoc"
aliases:
tags:
- cosc204
---
CMOC is a 6809 c compiler.
it compiles c code into 6809 assembly
callling conventions
- A routine must preserve Y, U, S and DP
- A routine may change A, B, X and CC
- Parameters are pushed on the stack in the reverse order
- The caller pops them off the stack after the call
- char parameters are promoted to int
- unsigned char are promoted to unsigned int
- Return 8-but values in B
- Return 16-bit values in D
# examples
parameters
``` c
uint16_t two_params(uint8_t first, uint16_t second) {
return first + second;
}
uint16_t call_one(void) {
return two_params(204, 431);
}
```
```
```
local variables
``` c
uint16_t one_param(uint16_t xyzzy) {
uint16_t val = xyzzy;
return val;
}
```
```
_one_param
PSHS U
LEAU ,S
LEAS -2,S
* Formal parameter(s):
* 4,U: 2 bytes: xyzzy
* Local non-static variable(s):
* -2,U: 2 bytes: val
LDD 4,U
STD -2,U
LEAS ,U
PULS U,PC
```

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@ -20,6 +20,9 @@ No final exam
- [cia-triad](notes/cia-triad.md)
- [cryptography](notes/cryptography.md)
- [randomness](notes/randomness.md)
- [authorisation](notes/authorisation.md)
- [authentication](notes/authentication.md)
- [passwords](notes/passwords.md)
# Lectures
- [01-information-assurance](notes/01-information-assurance.md)
@ -27,5 +30,3 @@ No final exam
- [03-threats-social-engineering-and-failures](notes/03-threats-social-engineering-and-failures.md)
- [04-authentication-authorisation-passwords](notes/04-authentication-authorisation-passwords.md)
- [05-cryptography](notes/05-cryptography.md)
# Archive

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@ -27,6 +27,7 @@ tags:
- [ALU](notes/ALU.md)
- [computer-architecture](notes/computer-architecture.md)
- [6809-addressing-modes](notes/6809-addressing-modes.md)
- [6809](notes/6809.md)
# Lectures
- [01-bits-and-bytes](notes/01-bits-and-bytes.md)

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---
title: "passwords"
aliases:
tags:
- comp210
---
# Passwords
- not good
- lots of bad advice
- we are lazy
- "safe" passwords are difficult to enter on touch screen devices
- to many accouts
## entropy
- amount of randomness
- measure of the number of guesse an attacker would need to brute foarce
- $E = log_2(A^L)$
- A = size of alphabet
- L = length of password
- E = entropy in bits
- 80 bits is "safe"
- would take decades
- 6 digits passoword - 29 bits (took 4 seconds to brute force)
- + uppercase and numbers - 36 bits