| mac_biba.4 (112860) | mac_biba.4 (115643) |
|---|---|
| 1.\" Copyright (c) 2002 Networks Associates Technology, Inc. 2.\" All rights reserved. 3.\" 4.\" This software was developed for the FreeBSD Project by Chris Costello 5.\" at Safeport Network Services and Network Associates Laboratories, the 6.\" Security Research Division of Network Associates, Inc. under 7.\" DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 8.\" DARPA CHATS research program. --- 14 unchanged lines hidden (view full) --- 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" | 1.\" Copyright (c) 2002 Networks Associates Technology, Inc. 2.\" All rights reserved. 3.\" 4.\" This software was developed for the FreeBSD Project by Chris Costello 5.\" at Safeport Network Services and Network Associates Laboratories, the 6.\" Security Research Division of Network Associates, Inc. under 7.\" DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 8.\" DARPA CHATS research program. --- 14 unchanged lines hidden (view full) --- 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" |
| 31.\" $FreeBSD: head/share/man/man4/mac_biba.4 112860 2003-03-31 08:08:59Z chris $ 32.Dd NOVEMBER 18, 2002 | 31.\" $FreeBSD: head/share/man/man4/mac_biba.4 115643 2003-06-01 21:52:59Z ru $ 32.\" 33.Dd November 18, 2002 |
| 33.Os 34.Dt MAC_BIBA 4 35.Sh NAME 36.Nm mac_biba | 34.Os 35.Dt MAC_BIBA 4 36.Sh NAME 37.Nm mac_biba |
| 37.Nd Biba data integrity policy | 38.Nd "Biba data integrity policy" |
| 38.Sh SYNOPSIS 39To compile Biba into your kernel, place the following lines in your kernel 40configuration file: | 39.Sh SYNOPSIS 40To compile Biba into your kernel, place the following lines in your kernel 41configuration file: |
| 42.Bd -ragged -offset indent |
|
| 41.Cd "options MAC" 42.Cd "options MAC_BIBA" | 43.Cd "options MAC" 44.Cd "options MAC_BIBA" |
| 45.Ed |
|
| 43.Pp 44Alternately, to load the Biba module at boot time, place the following line 45in your kernel configuration file: | 46.Pp 47Alternately, to load the Biba module at boot time, place the following line 48in your kernel configuration file: |
| 49.Bd -ragged -offset indent |
|
| 46.Cd "options MAC" | 50.Cd "options MAC" |
| 51.Ed |
|
| 47.Pp 48and in 49.Xr loader.conf 5 : | 52.Pp 53and in 54.Xr loader.conf 5 : |
| 50.Cd mac_biba_load= Ns \&"YES" | 55.Bd -literal -offset indent 56mac_biba_load="YES" 57.Ed |
| 51.Sh DESCRIPTION 52The 53.Nm 54policy module implements the Biba integrity model, 55which protects the integrity of system objects and subjects by means of 56a strict information flow policy. 57In Biba, all system subjects and objects are assigned integrity labels, made 58up of hierarchal grades, and non-hierarchal components. 59Together, these label elements permit all labels to be placed in a partial 60order, with information flow protections based on a dominance operator 61describing the order. 62The hierarchal grade field is expressed as a value between 0 and 65535, 63with higher values reflecting higher integrity. 64The non-hierarchal compartment field is expressed as a set of up to 256 65components, numbered from 0 to 255. 66A complete label consists of both hierarchal and non-hierarchal elements. 67.Pp 68Three special label values exist: | 58.Sh DESCRIPTION 59The 60.Nm 61policy module implements the Biba integrity model, 62which protects the integrity of system objects and subjects by means of 63a strict information flow policy. 64In Biba, all system subjects and objects are assigned integrity labels, made 65up of hierarchal grades, and non-hierarchal components. 66Together, these label elements permit all labels to be placed in a partial 67order, with information flow protections based on a dominance operator 68describing the order. 69The hierarchal grade field is expressed as a value between 0 and 65535, 70with higher values reflecting higher integrity. 71The non-hierarchal compartment field is expressed as a set of up to 256 72components, numbered from 0 to 255. 73A complete label consists of both hierarchal and non-hierarchal elements. 74.Pp 75Three special label values exist: |
| 69.Bl -column -offset indent "biba/equal" "lower than all other labels" | 76.Bl -column -offset indent ".Li biba/equal" "lower than all other labels" |
| 70.It Sy Label Ta Sy Comparison | 77.It Sy Label Ta Sy Comparison |
| 71.It Li biba/low Ta lower than all other labels 72.It Li biba/equal Ta equal to all other labels 73.It Li biba/high Ta higher than all other labels | 78.It Li biba/low Ta "lower than all other labels" 79.It Li biba/equal Ta "equal to all other labels" 80.It Li biba/high Ta "higher than all other labels" |
| 74.El 75.Pp 76The | 81.El 82.Pp 83The |
| 77.Dq biba/high | 84.Dq Li biba/high |
| 78label is assigned to system objects which affect the integrity of the system 79as a whole. | 85label is assigned to system objects which affect the integrity of the system 86as a whole. |
| 80.Dq biba/equal | 87The 88.Dq Li biba/equal 89label |
| 81may be used to indicate that a particular subject or object is exempt from 82the Biba protections. 83These special label values are not specified as containing any compartments, 84although in a label comparison, | 90may be used to indicate that a particular subject or object is exempt from 91the Biba protections. 92These special label values are not specified as containing any compartments, 93although in a label comparison, |
| 85.Dq biba/high | 94.Dq Li biba/high |
| 86appears to contain all compartments, | 95appears to contain all compartments, |
| 87.Dq biba/equal | 96.Dq Li biba/equal |
| 88the same compartments as the other label to which it is being compared, 89and | 97the same compartments as the other label to which it is being compared, 98and |
| 90.Dq biba/low | 99.Dq Li biba/low |
| 91none. 92.Pp 93In general, Biba access control takes the following model: 94.Bl -bullet 95.It 96A subject at the same integrity level as an object may both read from 97and write to the object as though Biba protections were not in place. 98.It --- 33 unchanged lines hidden (view full) --- 132Multi-Level Security (MLS) protects the confidentiality, rather than the 133integrity, of subjects and objects. 134.Ss Label Format 135Almost all system objects are tagged with a single, active label element, 136reflecting the integrity of the object, or integrity of the data contained 137in the object. 138In general, objects labels are represented in the following form: 139.Pp | 100none. 101.Pp 102In general, Biba access control takes the following model: 103.Bl -bullet 104.It 105A subject at the same integrity level as an object may both read from 106and write to the object as though Biba protections were not in place. 107.It --- 33 unchanged lines hidden (view full) --- 141Multi-Level Security (MLS) protects the confidentiality, rather than the 142integrity, of subjects and objects. 143.Ss Label Format 144Almost all system objects are tagged with a single, active label element, 145reflecting the integrity of the object, or integrity of the data contained 146in the object. 147In general, objects labels are represented in the following form: 148.Pp |
| 140.Dl biba/grade:compartments | 149.Sm off 150.D1 Li biba / Ar grade : compartments 151.Sm on |
| 141.Pp 142For example: 143.Pp 144.Bd -literal -offset indent 145biba/10:2+3+6 146biba/low 147.Ed 148.Pp 149Subject labels consist of three label elements: a single (active) label, 150as well as a range of available labels. 151This range is represented using two ordered Biba label elements, and when set 152on a process, permits the process to change its active label to any label of 153greater or equal integrity to the low end of the range, and lesser or equal 154integrity to the high end of the range. 155In general, subject labels are represented in the following form: 156.Pp | 152.Pp 153For example: 154.Pp 155.Bd -literal -offset indent 156biba/10:2+3+6 157biba/low 158.Ed 159.Pp 160Subject labels consist of three label elements: a single (active) label, 161as well as a range of available labels. 162This range is represented using two ordered Biba label elements, and when set 163on a process, permits the process to change its active label to any label of 164greater or equal integrity to the low end of the range, and lesser or equal 165integrity to the high end of the range. 166In general, subject labels are represented in the following form: 167.Pp |
| 157.Dl biba/singlegrade:singlecompartments(lograde:locompartments- 158.Dl higrade:hicompartments) | 168.Sm off 169.D1 Li biba / Ar singlegrade : singlecompartments ( lograde : locompartments - 170.D1 Ar higrade : hicompartments ) 171.Sm on |
| 159.Pp 160For example: 161.Bd -literal -offset indent 162biba/10:2+3+6(5:2+3-20:2+3+4+5+6) 163biba/high(low-high) 164.Ed 165.Pp 166Valid ranged labels must meet the following requirement regarding their 167elements: 168.Pp | 172.Pp 173For example: 174.Bd -literal -offset indent 175biba/10:2+3+6(5:2+3-20:2+3+4+5+6) 176biba/high(low-high) 177.Ed 178.Pp 179Valid ranged labels must meet the following requirement regarding their 180elements: 181.Pp |
| 169.Dl rangehigh >= single >= rangelow | 182.D1 Ar rangehigh No \[>=] Ar single No \[>=] Ar rangelow |
| 170.Pp 171One class of objects with ranges currently exists, the network interface. 172In the case of the network interface, the single label element references the 173default label for packets received over the interface, and the range 174represents the range of acceptable labels of packets to be transmitted over 175the interface. 176.Ss Runtime Configuration 177The following 178.Xr sysctl 8 179MIBs are available for fine-tuning the enforcement of this MAC policy. | 183.Pp 184One class of objects with ranges currently exists, the network interface. 185In the case of the network interface, the single label element references the 186default label for packets received over the interface, and the range 187represents the range of acceptable labels of packets to be transmitted over 188the interface. 189.Ss Runtime Configuration 190The following 191.Xr sysctl 8 192MIBs are available for fine-tuning the enforcement of this MAC policy. |
| 180.Bl -tag -width 'security.mac.biba.ptys_equal' | 193.Bl -tag -width ".Va security.mac.biba.ptys_equal" |
| 181.It Va security.mac.biba.enabled | 194.It Va security.mac.biba.enabled |
| 182Enables enforcement of the Biba integrity policy 183(Default: 1) | 195Enables enforcement of the Biba integrity policy. 196(Default: 1). |
| 184.It Va security.mac.biba.ptys_equal 185Label | 197.It Va security.mac.biba.ptys_equal 198Label |
| 186.Sm off 187.Xr pty 4 188s 189.Sm on | 199.Xr pty 4 Ns s |
| 190as | 200as |
| 191.Dq biba/equal 192upon creation 193(Default: 0) | 201.Dq Li biba/equal 202upon creation. 203(Default: 0). |
| 194.It Va security.mac.biba.revocation_enabled | 204.It Va security.mac.biba.revocation_enabled |
| 195Revoke access to objects if the label is changed to dominate the subject 196(Default: 0) | 205Revoke access to objects if the label is changed to dominate the subject. 206(Default: 0). |
| 197.El 198.Sh SEE ALSO 199.Xr lomac 4 , 200.Xr mac 4 , 201.Xr mac_bsdextended 4 , 202.Xr mac_ifoff 4 , 203.Xr mac_lomac 4 , 204.Xr mac_mls 4 , --- 4 unchanged lines hidden (view full) --- 209.Xr mac_test 4 , 210.Xr maclabel 7 , 211.Xr mac 9 212.Sh HISTORY 213The 214.Nm 215policy module first appeared in 216.Fx 5.0 | 207.El 208.Sh SEE ALSO 209.Xr lomac 4 , 210.Xr mac 4 , 211.Xr mac_bsdextended 4 , 212.Xr mac_ifoff 4 , 213.Xr mac_lomac 4 , 214.Xr mac_mls 4 , --- 4 unchanged lines hidden (view full) --- 219.Xr mac_test 4 , 220.Xr maclabel 7 , 221.Xr mac 9 222.Sh HISTORY 223The 224.Nm 225policy module first appeared in 226.Fx 5.0 |
| 217and was developed by the TrustedBSD Project. | 227and was developed by the 228.Tn TrustedBSD 229Project. |
| 218.Sh AUTHORS 219This software was contributed to the 220.Fx 221Project by Network Associates Labs, 222the Security Research Division of Network Associates | 230.Sh AUTHORS 231This software was contributed to the 232.Fx 233Project by Network Associates Labs, 234the Security Research Division of Network Associates |
| 223Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), | 235Inc. under DARPA/SPAWAR contract N66001-01-C-8035 236.Pq Dq CBOSS , |
| 224as part of the DARPA CHATS research program. | 237as part of the DARPA CHATS research program. |