1 1 00:00:00,420 --> 00:00:02,010 Privilege management. 2 2 00:00:02,010 --> 00:00:03,780 In this lesson, we're going to talk 3 3 00:00:03,780 --> 00:00:06,210 about the different forms of access control, 4 4 00:00:06,210 --> 00:00:08,370 because all of those relate to privileges. 5 5 00:00:08,370 --> 00:00:10,110 Now, when I talk about privilege management, 6 6 00:00:10,110 --> 00:00:11,520 which is the name of this lesson, 7 7 00:00:11,520 --> 00:00:13,530 this is the use of authentication 8 8 00:00:13,530 --> 00:00:16,230 and authorization mechanisms to provide an administrator 9 9 00:00:16,230 --> 00:00:18,570 with centralized or decentralized control 10 10 00:00:18,570 --> 00:00:21,330 of user and group role-based privilege management. 11 11 00:00:21,330 --> 00:00:24,030 Essentially, we want to make sure we're able to control 12 12 00:00:24,030 --> 00:00:26,970 what privileges a person or a group has, 13 13 00:00:26,970 --> 00:00:29,010 and we're going to do that based on their role. 14 14 00:00:29,010 --> 00:00:30,630 That is the best way to do it. 15 15 00:00:30,630 --> 00:00:32,160 So if I have people who work in accounting, 16 16 00:00:32,160 --> 00:00:33,450 they're going to have one set of permissions. 17 17 00:00:33,450 --> 00:00:34,560 If I have people who work in IT, 18 18 00:00:34,560 --> 00:00:36,060 they have a different set of permissions. 19 19 00:00:36,060 --> 00:00:37,140 If I have a regular user, 20 20 00:00:37,140 --> 00:00:38,820 they're going to have a different set of permissions. 21 21 00:00:38,820 --> 00:00:41,310 On my system, instructors have a different set 22 22 00:00:41,310 --> 00:00:42,510 of permissions than students 23 23 00:00:42,510 --> 00:00:44,940 because we have different roles that we have to do. 24 24 00:00:44,940 --> 00:00:46,980 Now, most of our policies are going to be designed 25 25 00:00:46,980 --> 00:00:47,820 with the principles 26 26 00:00:47,820 --> 00:00:50,370 of least privilege and separation of duty, 27 27 00:00:50,370 --> 00:00:51,900 and these are two key concepts 28 28 00:00:51,900 --> 00:00:53,430 that you have to be familiar with. 29 29 00:00:53,430 --> 00:00:55,410 Now, least privilege is pretty simple. 30 30 00:00:55,410 --> 00:00:57,120 That just means doing something 31 31 00:00:57,120 --> 00:00:59,520 with the lowest amount of privileges possible. 32 32 00:00:59,520 --> 00:01:01,140 If you can do it as a user, 33 33 00:01:01,140 --> 00:01:02,970 you're just going to do it with a user account. 34 34 00:01:02,970 --> 00:01:04,590 If you need to have administrative rights, 35 35 00:01:04,590 --> 00:01:07,260 do you need all administrative rights or just certain ones? 36 36 00:01:07,260 --> 00:01:09,450 If so, that would be a super user instead of 37 37 00:01:09,450 --> 00:01:10,770 an administrative user, 38 38 00:01:10,770 --> 00:01:13,050 and so you want to use that idea of least privilege. 39 39 00:01:13,050 --> 00:01:14,820 Now, with separation of duties, 40 40 00:01:14,820 --> 00:01:17,100 this is a means of establishing checks and balances 41 41 00:01:17,100 --> 00:01:19,680 against the possibility of insider threats, 42 42 00:01:19,680 --> 00:01:20,730 because these insider threats 43 43 00:01:20,730 --> 00:01:23,700 can compromise critical systems and procedures. 44 44 00:01:23,700 --> 00:01:25,560 Now, when we talk about separation of duties, 45 45 00:01:25,560 --> 00:01:27,840 this is a system of checks and balances. 46 46 00:01:27,840 --> 00:01:30,660 So in my company, we have a corporate checkbook. 47 47 00:01:30,660 --> 00:01:34,140 If somebody wants to sign a check, one person can't do that. 48 48 00:01:34,140 --> 00:01:36,600 Each of those checks has dual signatures. 49 49 00:01:36,600 --> 00:01:40,050 Now, that means that I can sign and my COO can sign 50 50 00:01:40,050 --> 00:01:41,880 and that means we can pay our bills that way. 51 51 00:01:41,880 --> 00:01:43,260 It's a little bit more cumbersome 52 52 00:01:43,260 --> 00:01:45,030 but it does make sure 53 53 00:01:45,030 --> 00:01:46,560 that nobody can just take the checkbook 54 54 00:01:46,560 --> 00:01:49,050 and do a single signature and steal all of our money. 55 55 00:01:49,050 --> 00:01:51,720 My COO can't go and fly to Vegas and spend all of our money. 56 56 00:01:51,720 --> 00:01:52,553 It doesn't work that way. 57 57 00:01:52,553 --> 00:01:54,540 She has to have both our signatures. 58 58 00:01:54,540 --> 00:01:56,730 That's the idea of a separation of duties here. 59 59 00:01:56,730 --> 00:01:57,900 Now, I mentioned at the beginning 60 60 00:01:57,900 --> 00:01:59,160 of this lesson we were going to talk 61 61 00:01:59,160 --> 00:02:00,360 about access control types. 62 62 00:02:00,360 --> 00:02:01,680 So, let's get into that. 63 63 00:02:01,680 --> 00:02:03,120 Access control types. 64 64 00:02:03,120 --> 00:02:05,700 There are four types of access controls. 65 65 00:02:05,700 --> 00:02:07,740 There is discretionary access control, 66 66 00:02:07,740 --> 00:02:10,770 mandatory access control, role-based access control 67 67 00:02:10,770 --> 00:02:13,020 and attribute based access control. 68 68 00:02:13,020 --> 00:02:15,900 Now, when we deal with discretionary access control or DAC, 69 69 00:02:15,900 --> 00:02:18,540 this is an access control model where each resource 70 70 00:02:18,540 --> 00:02:21,480 is protected by an access control list or ACL 71 71 00:02:21,480 --> 00:02:23,850 and it's managed by the resource owner or owners. 72 72 00:02:23,850 --> 00:02:25,350 If you use Microsoft Windows, 73 73 00:02:25,350 --> 00:02:28,110 you're familiar with DAC because that's what we use. 74 74 00:02:28,110 --> 00:02:30,960 You can right click on that properties button on the folder, 75 75 00:02:30,960 --> 00:02:32,370 you can go to a shared folder, 76 76 00:02:32,370 --> 00:02:34,290 you can right click on it and go to properties. 77 77 00:02:34,290 --> 00:02:36,600 And when you do that, you'll see the attributes associated 78 78 00:02:36,600 --> 00:02:38,160 with that access control list. 79 79 00:02:38,160 --> 00:02:40,200 It'll say what users can read, write 80 80 00:02:40,200 --> 00:02:41,700 or modify those folders. 81 81 00:02:41,700 --> 00:02:44,130 That's the whole idea of discretionary access control. 82 82 00:02:44,130 --> 00:02:47,250 The person who owns that resource can change those files 83 83 00:02:47,250 --> 00:02:49,590 and make anybody access it that they want. 84 84 00:02:49,590 --> 00:02:50,700 I, as assistant administrator, 85 85 00:02:50,700 --> 00:02:52,860 have access over the entire system as well. 86 86 00:02:52,860 --> 00:02:54,390 But Windows, by default, 87 87 00:02:54,390 --> 00:02:56,730 is a discretionary access control system. 88 88 00:02:56,730 --> 00:02:58,530 It is a DAC system. 89 89 00:02:58,530 --> 00:03:00,840 Now, beyond that, we can look into MAC, 90 90 00:03:00,840 --> 00:03:02,910 and MAC is a little bit more secure. 91 91 00:03:02,910 --> 00:03:04,650 MAC has a lot more overhead though. 92 92 00:03:04,650 --> 00:03:07,260 MAC is mandatory access control. 93 93 00:03:07,260 --> 00:03:09,570 This is an access control model where resources 94 94 00:03:09,570 --> 00:03:12,660 are protected by inflexible system defined rules 95 95 00:03:12,660 --> 00:03:16,650 where every resource or object and every user or subject 96 96 00:03:16,650 --> 00:03:19,590 is allocated a clearance level or a label. 97 97 00:03:19,590 --> 00:03:22,560 Whenever I hear about MAC, I always think about labels. 98 98 00:03:22,560 --> 00:03:23,730 Everything is labeled. 99 99 00:03:23,730 --> 00:03:26,280 And if you think about the standard military context, 100 100 00:03:26,280 --> 00:03:27,990 this is a MAC context. 101 101 00:03:27,990 --> 00:03:30,840 We have a document and it's either classified as secret, 102 102 00:03:30,840 --> 00:03:34,080 confidential, top secret, whatever that document is. 103 103 00:03:34,080 --> 00:03:36,930 That label then tells it how it it'll be treated 104 104 00:03:36,930 --> 00:03:38,370 inside of our system. 105 105 00:03:38,370 --> 00:03:39,810 Now, if I wanted to read this document 106 106 00:03:39,810 --> 00:03:41,280 it's going to check my account and say, 107 107 00:03:41,280 --> 00:03:43,380 Jason, what clearances does he have? 108 108 00:03:43,380 --> 00:03:47,340 He has top secret, secret, confidential, unclassified. 109 109 00:03:47,340 --> 00:03:48,990 That means he can read all four of those. 110 110 00:03:48,990 --> 00:03:50,610 Now, if we went and checked Mary's clearance 111 111 00:03:50,610 --> 00:03:52,200 and she only has secret, 112 112 00:03:52,200 --> 00:03:53,520 she wouldn't be able to read this document 113 113 00:03:53,520 --> 00:03:55,020 because this is a top secret document 114 114 00:03:55,020 --> 00:03:56,460 so it wouldn't show it to her. 115 115 00:03:56,460 --> 00:03:59,340 That's the idea of MAC, and that's how these systems work. 116 116 00:03:59,340 --> 00:04:02,610 Now, most operating systems do not support MAC 117 117 00:04:02,610 --> 00:04:04,380 but there is one that really does it well, 118 118 00:04:04,380 --> 00:04:06,120 and this is SELinux. 119 119 00:04:06,120 --> 00:04:07,410 SELinux was actually developed 120 120 00:04:07,410 --> 00:04:10,140 by the National Security Agency, the NSA, 121 121 00:04:10,140 --> 00:04:12,090 and it provides a method for implementing MAC 122 122 00:04:12,090 --> 00:04:13,140 within that network. 123 123 00:04:13,140 --> 00:04:15,600 So, if you want to use MAC, remember, 124 124 00:04:15,600 --> 00:04:17,130 there's a lot of overhead involved 125 125 00:04:17,130 --> 00:04:19,440 but if you have something that's very classified, 126 126 00:04:19,440 --> 00:04:22,350 it's a good system to use, and then you'd use SELinux. 127 127 00:04:22,350 --> 00:04:23,430 Now, the next one we want to talk about 128 128 00:04:23,430 --> 00:04:26,040 is role-based access control or RBAC. 129 129 00:04:26,040 --> 00:04:28,260 Now, RBAC is an access control model 130 130 00:04:28,260 --> 00:04:30,330 where resources are protected by ACLs 131 131 00:04:30,330 --> 00:04:31,770 that are managed by administrators 132 132 00:04:31,770 --> 00:04:35,070 and can provide user permissions based on job functions. 133 133 00:04:35,070 --> 00:04:37,260 So, going back to my earlier example, 134 134 00:04:37,260 --> 00:04:39,780 I take all my accountants and I put 'em in one group 135 135 00:04:39,780 --> 00:04:41,550 then I can give that group permissions. 136 136 00:04:41,550 --> 00:04:44,010 That would be a role-based access control. 137 137 00:04:44,010 --> 00:04:45,690 Because I'm going to be able to implement this 138 138 00:04:45,690 --> 00:04:47,730 through the concept of groups inside of Windows. 139 139 00:04:47,730 --> 00:04:49,590 That's the idea of doing RBAC. 140 140 00:04:49,590 --> 00:04:51,750 Now, this isn't a perfect implementation of RBAC 141 141 00:04:51,750 --> 00:04:54,510 but it does get the job done most of the way 142 142 00:04:54,510 --> 00:04:55,740 and so we will consider that 143 143 00:04:55,740 --> 00:04:58,320 an implementation inside of Windows. 144 144 00:04:58,320 --> 00:05:00,690 Another one we can use is attribute based. 145 145 00:05:00,690 --> 00:05:03,060 Attribute based access control or ABAC 146 146 00:05:03,060 --> 00:05:04,590 is an access control technique 147 147 00:05:04,590 --> 00:05:06,240 that evaluates a set of attributes 148 148 00:05:06,240 --> 00:05:07,860 that each subject possesses 149 149 00:05:07,860 --> 00:05:09,600 to determine if access should be granted. 150 150 00:05:09,600 --> 00:05:11,670 Now, ABAC can be used to implement controls 151 151 00:05:11,670 --> 00:05:13,290 for separation of duties. 152 152 00:05:13,290 --> 00:05:16,200 So, I can say that I'm part of the A group 153 153 00:05:16,200 --> 00:05:17,760 and somebody else is part of the B group. 154 154 00:05:17,760 --> 00:05:19,950 And based on that, we have certain attributes. 155 155 00:05:19,950 --> 00:05:20,880 So, there are certain things 156 156 00:05:20,880 --> 00:05:22,080 that A group people can do 157 157 00:05:22,080 --> 00:05:23,640 and B group people can do. 158 158 00:05:23,640 --> 00:05:26,520 And because of those attributes associated with each of us, 159 159 00:05:26,520 --> 00:05:27,810 we can then do certain things 160 160 00:05:27,810 --> 00:05:29,280 and that would separate our duties. 161 161 00:05:29,280 --> 00:05:32,760 ABAC is by far the most complicated type of access control 162 162 00:05:32,760 --> 00:05:33,600 to implement 163 163 00:05:33,600 --> 00:05:36,000 but it does give you the most flexibility 164 164 00:05:36,000 --> 00:05:38,430 because you're not doing things based on groups anymore, 165 165 00:05:38,430 --> 00:05:40,590 you're doing it based on a single subject. 166 166 00:05:40,590 --> 00:05:43,800 And so I can actually have down to the individual person 167 167 00:05:43,800 --> 00:05:45,780 what specific attributes they have 168 168 00:05:45,780 --> 00:05:48,060 and therefore what specific things they can do 169 169 00:05:48,060 --> 00:05:48,993 on that system.