Different Aspects of Security Problems in Network Operating Systems

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Description

• fiche de synthèse - matière potentielle : the experiments
• dissertation
• revision - matière potentielle : aslam
• exposé - matière potentielle : the unix

Vulnerabilities will probably always exist in large and complex software systems. At least with today's software methods, techniques, and tools, it seems to be impossible to completely eliminate all flaws. Operating systems are examples of software components that are large, very complex, and vulnerable. At the same time, these components play an important role in the achievement of overall system secu- rity, since many protection mechanisms and facilities, such as authentication and access Science students in Computer Science and Engineering attack the systems.

• most authenti- cation systems
• further step towards a full understanding of the generic weaknesses
• 5.1 software
• p. j.
• p.j.
• security
• systems
• 3 c.
• c.
• computer
• system

Sujets

• Dissertation
• Chalmers University of Technology
• Sandia National Laboratories

Informations

• Publié par: orzi
• Nombre de lectures: 23
• Langue: English

Extrait

V LA D IM I R K O R OL EN KO EASTER EVE T r a n s l a t e d a n o n y m o u s l y – X I X c e n t u r y It w a s H o l y Sa t u rd ay, o n e ye ar i n th e 'e ig h t i es . Ev e n in g h ad l o n g s i n ce en f o ld ed t h e s i l en t ea rt h . T h e g ro u n d , wa rme d d u r in g th e d a y b y th e r ays o f t h e su n , wa s n o w c o o l in g b e n e at h th e in v i g o r at in g i n fl u en ce o f t h e n ig h t- fro s t . It s e emed as if s i g h in g , w h il e i ts b re at h , fo rmin g a s il v er y mis t , ro s e g l is t en in g in t h e rays o f th e s ta rl it s k y, l i k e cl o u d s o f in c en se , t o g re et t h e a p p ro ac h i n g fe as t. Al l w as st i ll . I n t h e c o o l n i g h t -b re ez e t h e s ma ll p ro v i n c ia l to wn s to o d s i le n t , w ai ti n g t o h e ar t h e f i rs t s t ro k e o f th e b e l l fro m t h e h ig h c at h ed r al t o w er. B u t t h e to wn wa s n o t s le ep i n g ; a s p i ri t o f ex p ec ta n cy b ro o d e d b e n ea t h th e v ei l o f d ar k n es s , b r ea th i n g th r o u g h t h e s h a d o ws o f th e s il en t a n d d es e rt ed s t ree ts . N o w a n d t h en a b e la te d wo rk ma n , w h o h a d ju s t e s ca p ed f ro m h i s s e rv i le ta s k ere th e fe st i v al b eg a n , p a s s ed , h u rryin g o n h i s w ay; o n ce i n a w h i le a ca b ra tt l ed b y, l ea v in g s il en c e b eh in d it . L ife h a d f le d in d o o rs a n d h i d d en i t s el f, i n ma n s io n an d h o v el , fr o m wh o se w in d o ws t h e li g h t s sh o n e f ar o u t u p o n t h e st r e et , wh il e o v e r th e ci t y an d t h e f ie ld s h o v e re d th e sp ir i t o f R es u rr ec ti o n . Al th o u g h th e mo o n s to o d h ig h a b o v e th e h o ri z o n , th e to w n s t il l re s te d i n t h e b ro ad , d ee p s h a d o w o f a h i ll , cr o wn e d b y a g lo o my an d ma s s iv e e d i fic e, w h o s e p ec u l ia rl y s tra i g h t a n d s ev e re o u tl in e s we re s h a rp l y d e fin e d i n th e g o l d en a tmo s p h ere . Th e so mb re g at es w er e h a rd ly to b e d is t i n g u is h e d ami d th e g l o o m o f i ts d ee p ly s h a d o w ed wa l ls , wh il e t h e t o we rs o n th e fo u r c o rn e rs s to o d o u t b o l d l y ag a in st th e a zu re s k y, an d g ra d u al l y o v er a ll t h e m o o n p o u re d it s fl o o d o f li q u i d g o l d . Su d d en l y o n t h e s e n s it iv e ai r o f th e ex p e ct an t n ig h t c ame th e fi rs t s tr o k e fro m th e h ig h c at h ed r al b el fry; th en an o th e r,

an d s ti l l an o th e r. A mi n u te l at e r a n d th e w h o l e a ir t h ro b b e d an d s we ll ed , as t h e co u n tl es s b el ls r an g o u t, u n it i n g i n o n e h ar mo n i o u s p ea l. F ro m t h e g l o o my b u il d in g o v ers h a d i n g th e to w n c ame a f ai n t, b r o k en h a rmo n y, th a t s e emed t o f l u tt e r h el p l es s ly i n t h e ai r, a n d t h e n ce t o ri s e in t o th e e th e re al li g h t , a n d jo in t h e mig h ty c h o ru s . Th e si n g i n g ce as e d , th e s o u n d s d is s o l v ed i n ai r, a n d t h e s il en ce o f t h e n i g h t g ra d u al l y r es u me d it s s w ay; a fa in t ec h o s ee me d t o h o v e r fo r a w h i le , l ik e th e v ib r at io n o f a n i n v i s ib l e h a r p -s t ri n g . No w th e l i g h ts w ere g r ad u a ll y ex t i n g u i sh ed , th e c h u rc h wi n d o w s s h o n e f o rt h b r ig h t l y, a n d E art h s ee med re ad y t o p ro c la im o n ce mo re t h e o l d ti d i n g s o f p ea ce , l o v e , a n d g o o d -w i ll . Th e b o lt s o f th e d a rk g a te s in th e g l o o my b u il d i n g cr ea k ed , an d a b an d o f s o ld i e rs , w it h cl an k i n g arms , s al l ie d fo rt h to re li ev e th e n i g h t s e n ti n e ls ; o n a p p ro a ch i n g th e co r n ers , th ey w o u ld h a lt , a n d a d a rk fo rm, w it h me a s u re d s te p s , w o u l d d e ta ch i ts e lf fr o m th e res t , w h i le t h e fo r me r s en t in el to o k h i s p la ce i n th e ran k s , a n d t h e s o l d i e rs w en t o n th e ir w ay, s k i rt in g t h e h i g h p ris o n w al l , t h at g li s te n ed i n th e mo o n b ea ms . As th e y rea ch e d it s w es t ern s i d e, a yo u n g rec ru i t s t ep p e d fo rw a rd fro m t h e ra n k s to re l ie v e t h e s en t ry w h o wa s p o s te d th e re ; a ru st i c aw k w ard n es s st i ll sh o we d it s el f in h i s mo v e me n ts , an d h i s yo u n g fa ce b et ra yed t h e a b s o rb e d at te n t io n o f a n o v i ce w h o wa s t o o cc u p y fo r th e fir st ti me a re sp o n s ib l e p o s t . He f ac ed t h e w al l , p r es en te d arms , mad e tw o s te p s f o rw ard , a n d sh o u ld e ri n g h is ri fl e, s to o d b e s id e th e s en try h e wa s to re p la ce . Th e l at te r, t u rn i n g s l ig h t l y to w a rd h i m, r ep e at ed th e u s u a l fo rmu l a, i n t h e s in g - s o n g to n e o f d i s ci p li n e : " Fr o m co rn er to co r n er . Ke ep w at ch ! D o n o t s l ee p o r d o ze ! " He s p o k e r ap i d ly, wh il e th e r ec ru i t li s te n e d w it h cl o s e at te n ti o n , a n d a p e cu l ia r e x p re s s io n o f a n x i e t y a n d s ad n e s s i n h i s g r ey e yes . " Y o u u n d e rs ta n d ? " as k e d th e s erg e an t. " Y es , s ir! " " Th e n , l o o k o u t! " h e a d d e d s h a rp l y; b u t , s u d d e n l y ch a n g i n g h is t o n e, h e s a id , g o o d -n at u re d l y: " D o n 't b e a fra i d , F ad d eye f; yo u a re n o t a wo man ! I h o p e yo u ar e n o t afr ai d o f t h e Lyes h y! '' " W h y s h o u l d I b e a fra i d o f h im? " re p l ie d F ad d eye f .

Th e n h e a d d ed : " B u t I t el l yo u , b o ys , I h a v e s o me mi s g iv i n g ." Th i s s imp le a n d al mo s t c h il d i s h c o n fe ss i o n mad e th e s o ld i e rs l a u g h . " Th e re's s i mp l ic it y fo r yo u ! " e x cl a ime d th e s e rg e an t , i n to n es o f c o n te mp t . Th en g iv i n g t h e o rd e r, " Sh o u ld e r arms ! M a rc h ! " t h e s en t ri es , wi th mea s u red t re ad , d is a p p e a re d ar o u n d th e co rn er , an d t h e s o u n d o f th ei r fo o t s te p s wa s s o o n l o s t in th e d i s ta n ce . Th e s e n ti n el s h o u ld e red h i s ri fle , an d b e g an t o p a ce a l o n g th e wa ll . In s id e th e p ri so n , a t t h e fi rs t s t ro k e o f t h e b el l, al l w a s i n mo t io n . It w a s lo n g si n c e t h e s a d an d g lo o my p r is o n n i g h t h ad w it n es s e d s o mu c h l i fe. It s e emed as if t h e c h u rch b e ll s h ad re al ly b r o u g h t t id i n g s o f li b er ty; fo r th e g rim y d o o rs o f th e ce ll s o p e n ed i n t u rn , an d t h e ir o cc u p an t s , cl ad i n l o n g g re y g ar me n ts , th e fa ta l p at ch e s o n t h ei r b a ck s , fi le d i n ro w s al o n g t h e c o rri d o rs , o n t h e ir w a y t o th e b ri l l i an t l y li g h t ed p r is o n ch u rch . Th ey c ame fro m al l d i re ct io n s — fro m ri g h t a n d l eft , d es c en d i n g a n d as c en d i n g t h e s t ai rw ay; a n d amid t h e ec h o i n g fo o t s te p s ra n g t h e so u n d o f arms a n d th e cl an k in g o f ch a i n s . O n e n te ri n g t h e c h u rc h , th is g r e y mas s o f h u ma n it y p o u red i n to th e s p a ce a ll o t te d t o i t, b eh i n d th e ra il in g , a n d s to o d t h er e i n s i l en c e. Th e wi n d o w s o f th e ch u r ch w er e p ro t ec t ed b y s t ro n g i ro n b ar s . Th e p ri s o n w as e mp t y, e x ce p t in th e fo u r t o we rs , w h er e, in s ma ll , s tr o n g l y b o l te d c el l s, fo u r me n , i n s o l it ar y co n f in e me n t, w er e re s tl es s l y p ac in g to a n d fro , s t o p p i n g o n ce i n a w h il e t o l is t en a t t h e k eyh o le to t h e sn a t ch e s o f ch u r ch - si n g i n g th at rea ch e d th ei r ea rs . An d , b e si d e t h es e , i n o n e o f t h e o r d in a ry c el ls , in a b u n k , la y a s ic k ma n . Th e g o v e rn o r, t o w h o m th i s s u d d en i l l n es s h ad b e en re p o rt ed , we n t i n to h i s ce l l as th e y we re e s co rt i n g th e p r is o n e rs t o c h u rch , an d , l e an i n g o v e r h im, lo o k ed i n t o h is eye s , t h at w er e g az in g fi x e d ly b e fo re h i m, an d in w h ic h s h o n e a p e cu l ia r l i g h t. " Iv an o f ! Iv a n o f! " h e c al l e d o u t t o th e i n v al id . T h e c o n v i ct n ev e r t u rn e d h is h e ad , b u t co n t i n u ed mu t te ri n g s o me th i n g u n i n t el li g i b le , mo v i n g h i s p ar ch e d li p s wi t h d iff ic u lt y. " C ar ry h im t o th e h o s p it a l t o -mo r ro w ! " s ai d th e g o v e rn o r, as h e l e ft t h e c el l, a p p o in t i n g a s en t ry t o g u ar d th e d o o r. T h e l at t er, a ft er a cl o s e e x amin a t io n o f th e d el i rio u s p a ti e n t, s h o o k h is h e ad , s ayi n g as h e d id s o : " A

v ag r an t ! Po o r f el lo w! yo u ar e n o t l ik e ly t o tra mp a n y mo re ! " T h e g o v e rn o r c o n t in u e d h is w ay a lo n g t h e c o rri d o r , a n d en t er ed t h e c h u rc h , ta k i n g u p h i s p o st b y t h e d o o r, w h ere , wi t h fr eq u e n t g en u fle x i o n s , h e li s te n e d d e v o u tl y to th e s erv i c e. M e an wh i le t h e mu tt er in g s o f th e u n c o n s ci o u s ma n fi ll ed t h e e mp t y ce l l. He d id n o t se em o ld ; o n th e co n tra ry, h e lo o k e d s tr o n g an d mu s cu l ar . H e wa s d el ir io u s , a p p are n t ly l i v in g t h e p as t o v er a g a in , wh il e a l o o k o f d i s tr es s d is fi g u re d h is fa ce . F a te h ad p la ye d h i m a s o rry tr ic k . H e h a d t ra mp e d t h o u s a n d s o f mi le s th r o u g h th e S ib e ri an fo r es t s a n d mo u n ta in s, h a d s u ffe red c o u n tl e ss d an g ers an d p ri v at i o n s , al w ays u rg e d o n w ard b y a co n s u min g h o me -s ic k n e ss , a n d s u s t ai n ed b y o n e h o p e — th a t h e mig h t li v e t o s e e h i s n a ti v e p l ac e , an d b e o n ce mo re wi t h h i s o w n p e o p le , i f i t we re b u t fo r a mo n t h , o r ev e n a w ee k . Th e n h e w o u l d b e re s ig n ed , e v en i f h e h a d to g o b ac k a g ai n . B u t it ch an c ed t h a t, w h en o n ly a f ew h u n d re d mi le s fro m h is n a ti v e v il la g e , h e h a d b ee n re ca p tu r ed a n d c o n fi n ed i n t h i s p ri so n . Su d d en l y h i s mu t te ri n g s ce as e d . H i s e ye s d i l at ed , an d h is b re at h i n g b ec ame mo re e v en . B ri g h t er d re ams fl it t ed ac ro s s h i s fe v ere d b ra in . T h e f o res t mo a n s . He k n o w s it we l l, t h at mo a n in g ; mo n o t o n o u s , mu si ca l , an d p o w erf u l. H e ca n d is t i n g u is h it s v a ri o u s t o n es ; t h e l an g u a g e o f ea ch tr ee : th e ma je s ti c p in e , d u s k y g re en , ru s tl i n g h i g h o v erh ea d ; th e wh is p e rin g c ed ars , th e b ri g h t , merr y b ir ch , to s s i n g it s fl ex i b l e b r an c h es ; th e t re mb l in g as p en , flu t t eri n g i t s ti mi d , s en s i ti v e le av e s . Th e fr ee b i rd s s i n g ; th e s t ea m ru sh e s ac ro s s t h e s to n y c h as m; a n d a s w ar m o f g i b b e rin g ma g p i es , th e d e te ct iv es o f t h e fo re s t, a re s o a ri n g i n th e a i r o v er th e p at h fo l lo w ed b y th e v ag r an t t h ro u g h t h is al mo s t imp en e t rab l e t h i ck e t. It s ee me d a s if a b re ez e fro m t h e fre e fo re s t w ere w af te d th r o u g h t h e p ri s o n c el l . Th e i n v a li d s a t u p a n d d re w a l o n g b re at h , g a zi n g in t en tl y b efo r e h i m, w h i le a s u d d en g l ea m o f co n s c io u sn es s fl a sh e d in t o h i s e ye s. Th e v a g ra n t, t h e h ab i t u al fu g it iv e, b e h el d b e fo r e h i m an u n ac cu s t o me d s ig h t — an o p e n d o o r! In h i s f rame, e n fe eb l e d b y d is e as e , a p o w erf u l in st i n ct s p ran g t o l if e. Hi s d e li ri u m ei th er d i sa p p e are d o r c en t re d it s el f o n o n e i d ea , wh i c h , li k e a ra y o f s u n l i g h t, i ll u min e d th e ch a o s o f h i s t h o u g h t s . A l o n e, an d w it h a n o p en d o o r ! I n

a mo me n t h e w a s o n h i s fe et . It s ee me d a s if th e f e v e r h a d le ft h is b r ai n , an d w as o n l y p e rc ep t ib le in h i s eye s , w h ic h h ad a fi x ed a n d men a ci n g e x p re ss i o n . So me o n e h a d ju s t co me o u t f ro m th e ch u r ch , le av i n g th e d o o r a ja r. Th e s tr ai n s o f th e h armo n io u s s in g in g , s u b d u ed b y t h e d is t an ce , re ac h ed t h e ea r o f th e v ag r an t , a n d th e n d ie d aw ay. H is fa ce s o f te n ed , h i s e yes g re w d i m, an d h i s imag i n a ti o n re p ro d u c ed a l o n g - ch e ris h e d s c en e : A mi l d n ig h t, th e wh i s p er o f t h e p i n es , th e ir b r an c h es s wa yi n g ab o v e th e o l d c h u rc h o f h i s n a ti v e v il la g e, a t h ro n g o f co u n trymen ; t h e li g h t s re fl ec te d i n t h e r iv e r, a n d t h i s sa me ch a n t ! H e mu st ma k e h as t e w it h h is jo u r n ey, t h at h e ma y h ea r t h is at h o me , wi th h is fa mi ly! Al l t h i s t ime, i n th e co rr id o r, n ea r th e ch u rch d o o r, th e g o v e rn o r p r aye d d e v o u t ly, k n ee li n g , a n d t o u ch i n g h i s fo re h ea d t o t h e g ro u n d . M ea n w h il e , th e yo u n g rec ru i t p ac ed t o a n d fr o o n h i s b ea t a lo n g th e p ri s o n wa ll , wh i ch g lo w ed w i th a p h o s p h o re s ce n t li g h t . A b ro a d , l ev e l f ie ld , rec en tl y fr ee d fro m sn o w, l ay b e fo re h im. A li g h t w in d ru s t le d th r o u g h t h e t al l g ra s s , i n cl in i n g h i m to a s ad an d p en s i v e mo o d . Th e mo o n h u n g h i g h ab o v e th e h o ri zo n ; th e ex p r es s io n o f an x i e ty h a d v an is h e d fro m Fa d d eyef's fac e. H e s t o p p ed b y th e w al l, a n d , s et t in g h is r ifl e o n t h e g ro u n d , r es te d h i s h an d o n t h e mu z zl e , o n w h ic h h e l ea n ed h i s h e ad , fa ll i n g in t o a d e ep re v eri e . He c o u ld n o t ye t wh o ll y g r as p th e i d ea o f h is p res e n ce i n t h i s p l ac e, o n t h is so l e mn E as t e r Ev e , b es i d e t h e w al l , w i th a rif le in h i s h an d , a n d o p p o s i te th e v ac an t fi el d . He h ad b y n o me an s c ea se d to b e a p e a s a n t; ma n y t h i n g s c le ar t o a so l d i er w ere to h im in c o mp reh e n s ib l e ; an d h e w as o ft en t ea s ed b y b e in g c al l ed " a r u s ti c." B u t a s h o rt t ime a g o h e wa s a f ree ma n , h ad th e ca re o f a h o u se h o l d , o w n e d a f ie ld , an d w as at li b e r ty t o wo rk w h en a n d w h er e h e p l ea se d . N o w, a n i n d ef in i te , in e x p l ic ab l e fe ar b es e t h i s ev e ry s te p a n d mo v emen t , fo rc in g t h e a wk w a rd yo u n g p ea s an t in t o th e g ro o v e o f s t ri ct d is c ip li n e. A t th i s mo men t h e w as a lo n e . Th e b l ea k la n d s ca p e b efo r e h i m, an d th e wi n d , w h is t li n g t h ro u g h th e d ry g ra ss , mad e h im d re amy; a n d memo rie s o f fa mi li a r s ce n es p as s ed th r o u g h h is mi n d . H e se emed to s ee h i s