Q.'&BFJaw.oJfE@4f$;4<?:$,;:5<:
For this reason, security-sensitive code
that may require immediate updates
should be kept out of the database server
whenever possible. The stunnel utility
meets this requirement very well.
FEATURE: Stunnel Security
4HE LISTENER WILL GENERATE A STARTUP MESSAGE SIMILAR TO THE OUTPUT BELOW
F)2'B0F,8A<,F@49L3,v#<;@A4,PgTPTdTgTd,!,/<A79?:@A4,A4,, ,´Pk!`Jq!gdPp,PV3Pn3YY,
,
BA%><@=":,R?X,PkkP_,gdPM_,.<5?$#T,,&$$,<@=":;,<#;#<H#7T, ,
):5<:@4=,f"A6#fA<5?$#f.<5Pg?f7EfE@4f:4;$;4<3,%$#5;#,K5@:TTT, ,
02)F)2',8A<,F@49L3,v#<;@A4,PgTPTdTgTd,!,/<A79?:@A4,
)>;:#6,%5<56#:#<,8@$#,@;,f"A6#fA<5?$#f.<5Pg?f7Ef4#:KA<Gf,
´576@4f$@;:#4#<TA<5,
FA=,6#;;5=#;,K<@::#4,:A,f"A6#fA<5?$#f.<5Pg?f7@5=f:4;$;4<f,
´w.)02&oJf$@;:#4#<f5$#<:f$A=TL6$,
F@;:#4@4=,A43,RCJ)B'1/01.2*R&CC'J))*R/'.0.B.F*:?%XRw.)0*PTgTVTMX,
´R/.'0*PYgPXXX,
F@;:#4@4=,A43,RCJ)B'1/01.2*R&CC'J))*R/'.0.B.F*@%?XRIJ{*Jm0/'.BXXX, ,
BA44#?:@4=,:A,RCJ)B'1/01.2*R&CC'J))*R/'.0.B.F*0B/XRw.)0*PTgTVTMX,
´R/.'0*PYgPXXX,
)0&0Z),A8,:"#,F1)0J2J',
!!!!!!!!!!!!!!!!!!!!!!!!,
&$@5;,,,,,,,,,,,,,F1)0J2J',
v#<;@A4,,,,,,,,,,,02)F)2',8A<,F@49L3,v#<;@A4,PgTPTdTgTd,!,/<A79?:@A4, ):5<:,C5:#,,,,,,,,Pk!`Jq!gdPp,PV3Pn3YY,
Z%:@6#,,,,,,,,,,,,d,75>;,d,"<T,d,6@4T,d,;#?, 0<5?#,F#H#$,,,,,,,A88,
)#?9<@:>,,,,,,,,,,.23,FA?5$,.),&9:"#4:@?5:@A4, )2o/,,,,,,,,,,,,,,.``,
/5<56#:#<,`@$#,,,,f"A6#fA<5?$#f.<5Pg?f7Ef4#:KA<Gf576@4f$@;:#4#<TA<5, F@;:#4#<,FA=,`@$#,f"A6#fA<5?$#f.<5Pg?f7@5=f:4;$;4<fw.)02&oJf$@;:#4#<f,
´5$#<:f$A=TL6$,
F@;:#4@4=,J47%A@4:;,)9665<>TTT,
,,RCJ)B'1/01.2*R&CC'J))*R/'.0.B.F*:?%XRw.)0*PTgTVTMXR/.'0*PYgPXXX, ,,RCJ)B'1/01.2*R&CC'J))*R/'.0.B.F*@%?XRIJ{*Jm0/'.BXXX,
)#<H@?#;,)9665<>TTT,
FEATURE: Stunnel Security
)#<H@?#,+6>7E+,"5;,P,@4;:54?#R;XT,
,,14;:54?#,+6>7E+_,;:5:9;,Z2I2.s2_,"5;,P,"547$#<R;X,8A<,:"@;,;#<H@?#TTT, 0"#,?A66547,?A6%$#:#7,;9??#;;89$$>
)T IS IMPORTANT THAT THE LISTENER NOT ENGAGE IN hPORT REDIRECTIONv OF CLIENTS TO SEPARATE SERVER PORTS MOST COMMONLY SEEN IN -433HARED 3ERVER !NY FEATURE CAUSING THE 4.3 ,ISTENER TO ENGAGE IN SUCH activity must be disabled.
4O CONFIGURE STUNNEL THE ROOT USER MUST CREATE A KEYPAIR FOR 4,3 4HIS KEYPAIR CAN BE hSIGNEDv BY A #ERTIFICATE !UTHORITY #! IF DESIREDTHIS IS CONVENTIONALLY USEFUL FOR 7EB SITE ENCRYPTION (4403 SINCE THE LACK OF A RECOGNIZED #! SIGNATURE WILL TRIGGER BROWSER
SECURITY WARNINGS /RACLE CLIENTS CAN VERIFY SERVER KEYS ONLY WHEN SIGNED BY A RECOGNIZED #! WHICH IS ADDRESSED IN THE FINAL SECTION OF THIS ARTICLE 4O OBTAINED SIGNED KEYS FOLLOW THE INSTRUCTIONS ON THE STUNNEL 7EB SITE https://www.stunnel.org/howto.html /THERWISE FOR MORE INFORMAL USE A SELF SIGNED KEY CAN BE GENERATED WITH THE FOLLOWING COMMANDS
?7,f#:?f%G@f:$;f?#<:;, 65G#,;:944#$T%#6
4HE PROCESS OF KEY GENERATION WILL ASK A NUMBER OF QUESTIONS
(#4#<5:@4=,5,gdMn,E@:,')&,%<@H5:#,G#>,
TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTiii, TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTiii,
K<@:@4=,4#K,%<@H5:#,G#>,:A,Df:6%fA%#4;;$T"m/V=sD,
!!!!!,
{A9,5<#,5EA9:,:A,E#,5;G#7,:A,#4:#<,@48A<65:@A4,:"5:,K@$$,E#,@4?A<%A<5:#7,
@4:A,>A9<,?#<:@8@?5:#,<#j9#;:T,
s"5:,>A9,5<#,5EA9:,:A,#4:#<,@;,K"5:,@;,?5$$#7,5,C@;:@4=9@;"#7,256#,, A<,5,C2T,
0"#<#,5<#,j9@:#,5,8#K,8@#$7;,E9:,>A9,?54,$#5H#,;A6#,E$54G,
`A<,;A6#,8@#$7;,:"#<#,K@$$,E#,5,7#859$:,H5$9#_, 18,>A9,#4:#<,DTD_,:"#,8@#$7,K@$$,E#,$#8:,E$54GT,
FEATURE: Stunnel Security
!!!!!,
BA94:<>,256#,Rg,$#::#<,?A7#X,\mm]3Z), ):5:#,A<,/<AH@4?#,256#,R89$$,456#X,\]31F,
FA?5$@:>,256#,R#=_,?@:>X,\C#859$:,B@:>]3B"@?5=A,
.<=54@r5:@A4,256#,R#=_,?A6%54>X,\C#859$:,BA6%54>,F:7]3&BoJ,BA<%A<5:@A4, .<=54@r5:@A45$,Z4@:,256#,R#=_,;#?:@A4X,\]3s@7=#:,C@H@;@A4,
BA66A4,256#,R#=_,>A9<,456#,A<,>A9<,;#<H#<D;,"A;:456#X,\]375<G;:5<, J65@$,&77<#;;,\]3$@49;U%A;@LTA<=
4HE KEY PRODUCED ABOVE WILL BE SET FOR EXPIRATION IN DAYS FROM THE DAY IT WAS CREATED )F YOU WOULD LIKE TO GENERATE A KEY WITH A LONGER LIFE you can call OpenSSL directly:
A%#4;;$,<#j,!4#K,!LYdk,!75>;,VpYd,!4A7#;,c, , !A9:,;:944#$T%#6,!G#>A9:,;:944#$T%#6
4HE KEY WILL LOOK SOMETHING LIKE THIS
-,?5:,f#:?f%G@f:$;f?#<:;f;:944#$T%#6,
!!!!!qJ(12,/'1v&0J,IJ{!!!!!,
o11JH=1q&C&2q=Gj"G@(kKdq&uJ`&&)BqI=K==)G&=J&&A1q&uBgV6iKdqFL1grq, f%nf0@9`?J9<0FEFBuK?.f`JiH2?|%77?G9`pfv=%q&|Gi7k@l2}2j<[owlPPwPn, V&{"#K}0BE'ZouJV475{J1L):Mu"E6nmE8Z8Lp`6=MB4s"fmrJlqn}lmEw%K'uM7, Gu.r1BrEP4:kpuI7sA&AElVi"Hlj7@VZ[|VfgdrVBLYFs8sA5Vg{Ydff:Hq[q:?u, wlu%@Jg:8Fsw0uY:r:Gjv{fo}|sv=A0YF4ju$}#}qfBM@r){2AkJ(&4KM0"5`|f>, 27H6>Ip;{5.VCjM#`.ln.irrj>8"/B:?8En$o9'0}5n9@Hlr@v8d&V#()KI{A4Z8,
@Fl;9dG|&=oq&&JB==J&)>#CGYJu`k}2/[Z?dm({Yvq/5.GK/jvF.:7/K:iVM($[, rkVw.q0/v}}m6/=sF0>5>:`>r?=B"}$n;0w[9>FI5|As5w:rs%M7;{Z<"$;L[(/o,
#Cp)8);{1fk<=$Hq:4@5l{Mv[n78ZAB9g6H?<g2Fr`sF[>s)JMZn161pw0lL>/P>, Y&En|{mYBdj.C0[[/$7AHrn`6kmJl>Iv=Ymuk5&n5LjP9s{l<9rLm$@fi"l0|F/#, Hf>BB#IFjFi=)G.'["=n};Ifk%p14o2p9`Z#)HEd{k#F4F4|p:BZ("M6i?=m9$<C, Z$#mL#`rL4)V>7B2wvC4=m>5|PZiEF(v#w.F'?}w&uIq=uC{Y[Zi<Znv/m<E/|5#, 8}n;K8V/@dduZI2M/Y}>>Y?;PnIo=C'w'5Z7{6vB%01)'ls@dmwJ1l@wC%I$FffG, rB0dFsi8GiM&lE/Y>Z"FF:7PlY'Z%'V@#q9mE&}'jC5/oC|PL%}[i"C@)"/Hi.(', GlJ04qC6frGP0i`gF9pj#EFE?uIq=uCmPEp1l#'CG>`}10}mPHi)p/GA0ouo#B(m,
?)KvH9C9@;r=E8l116sHH`L7l"is|}JvHM[vpMYF.;HG{pm>`m7sl@2|(GI=0"=p,
FEATURE: Stunnel Security
{2JVmY8PA(HAYJViw2m)VH(;lp{vI0<5C7d)I1'0kn6g[@mBvBKiIs$'Y('iL%g&, n#LBA0{F(uIq=uC|7?69PE<(:lK22$(u`1Y;/B2F);f"8M0s=f$LP<=<Y%H`7In5,
|&M"|.:MMM#(=>)j86kPq:@gsZ<oolJrBAjA{@:rL);[A5sL2oHY))Cw{@=?`9(0, 11L&ouM2#4">:K645r0dPp=4qr72"}si5E84L9moI/o>(s=||EYM@sJ8=uIq=uCv, 2VL=82wKLYAn(1GnKvwnpvsjoqHJ0EBLGosB/#>jiG76:AF%};(}$l)/H[:|n%58, IVs?C4s$Ek1{FrB>oip.gfm0;l2YksK2rlo#L<jL$#EJ00sm&'$@${#7P5[g{jIs, MH?H"Ko@@C@6:ZA<lZ?fjvdVV>MfY>6v'6@$?#@mGuIq=JE`"&Im/kj}o78F#Hs%, vm&}B?Y6ug"Lu.)u'&FYvH0Zm6p}Kvmv8fZMg|wV{m@vmEKCEJ[[L)fno:)EuZkr, FAvufiEH?VLudn9nGL7u@sr0rK'Lw|ofr4L%ACk5;:1:jM9sZYn"BAZ21:wJI(|:, pdE?r79V<}F}1qP4gr)op;A`,
!!!!!J2C,/'1v&0J,IJ{!!!!!,
!!!!!qJ(12,BJ'01`1B&0J!!!!!,
o11Cf0BB&9s=&K1q&=1|&F0fk;GBH7'Yo&d(B)j()1EVCuJqBKZ&o1(Zou;KBu{C, vuu(JK|vZrJFo&G(&PZJB&KB)ZKLJC&.q=2vq&?oqd2A5s2"}gnL(0&mq=2vq&Ao, JJ`C0ZZ=ugk>?(k>{m'%EgML(C&sq=2vq&;oCP7%}(7$7BqJ5m}%?g$HE[J'o&n(,
&PZJ&KK1}(`>5V2d{m1Lw[&?q=Gj"G@(kKdqBuJsCgL%E4vruwqH?g$MF6k>}r&#,
`KdL20JKor&Kor1g20|5`Kd>20JKo[?Kor1g20|5o1(Zou;KBu{Cvuu(JK|vZrJF, o&G(&PZJB&KB)ZKLJC&.q=2vq&?oqd2A5s2"}gnL(0&mq=2vq&AoJJ`C0ZZ=ugk>,
?(k>{m'%EgML(C&sq=2vq&;oCP7%}(7$7BqJ5m}%?g$HE[J'o&n(&PZJ&KK1}(`>, 5V2d{m1Lw[&?q=Gj"G@(kKdqBuJsCgL%E4vruwqH?g$MF6k>}rBB&)1KCu{|IA}1,
"H?2&uJqqu&C==J/&CBB&uAB==Jq&FE#ElCuJHJ[Eowi4rk.IMvK)p:o:;;|CqKl, nZ0pnPK6$PP>)Mm<ksBGJ&60YVgF;PGgj9oK8HmZ8mr?q@`lq$o|:`uL&0#7P%=u, [`IV"B`9EL7:k'fwAs5C=I75wk8o0;wL4:7;#4q`C"g'&lo=F2Hs#VV%&%P5=B"H, H8p(f9%gF7)o48fE0/?FwG:}k5"<8}[40fign(o(PL&8:B6105Pn:{72C6V.g)%v, [nLG$}sB"/G9#%Bv$YGwnF@F2|=g[du{B8C".`AZ4f1PgiE1<jL"Al?.<"MZlHKl, l/.<|iJnIPLkH>Z>Y`2$<>pIfH.|vfuC7M}F&%@@7'i1H9>l)uGB&KJ&&52uoJMK, wu{Cv'd.qq{J`J=B7J2|iP>d)0o>u:9rV9jC.2V2oqn(&PZ71Ku{oq5&`J=B7J2|, iP>d)0o>u:9rV9jC.2V2o&K(&PZ7JKu`o&oq&8nKCu{|IA}1"H?2&uJFqu&C==Jq,
&10sl?q27sq?=5=;@4(I8>J)q$|l|HLH;or{v"1n6>Bn":fV4`o>0w6q=:6L72Es, 6BBrC7#)@=u8f@JrwdgGfJIlFl1VC&0(qspKks@{q7j<}|$knB1LA{k[i(vd&#FP, 12o)EY(M'g>=4#Gmv20|;1B#vw0'9[q|;CM%;}qY7")1nnn<&go<7un[&`(CGl}M, v{?G&g=uild>mmL%`)CM4g#?jV#E2:#[dlr'gK&:&G:f|:9(@Z[E$P6M}`0/A0K<, LC{o?#rJ=A%or{o@"HpBudBJZijFikgB{:JC;7P"r4lM)$qIkwoI[oF<Eq}/"EJM, f|o'sYA5fi0`}1'?5?0L=&K*,
!!!!!J2C,BJ'01`1B&0J!!!!!
FEATURE: Stunnel Security
4HE /'1v&0J,IJ{ SECTION ABOVE IS THE MOST SENSITIVE PORTION OF THE FILE ENSURE THAT IT IS NOT SEEN OR COPIED BY ANYONE THAT YOU DO not trust, and any recordings on backup media should be encrypted.
4HE qJ(12,BJ'01`1B&0J SECTION IS PRESENTED TO 4,3 CLIENTS THAT IS SQLPLUS WHEN THEY CONNECT TO STUNNEL
)T IS LIKELY WISE TO COMPUTE CUSTOM PRIMES FOR THE $IFFIE (ELLMAN KEY EXCHANGE ALGORITHM FOLLOWING GUIDANCE FROM THE STUNNEL manual page:
A%#4;;$,7"%5<56,gdMn,NN,;:944#$T%#6
4HE PREVIOUS COMMAND WILL ADD ANOTHER SECTION TO YOUR STUNNELPEM FILE FOR HIGH SECURITY $IFFIE (ELLMAN PRIMES
!!!!!qJ(12,Cw,/&'&oJ0J')!!!!!,
o11qB&IB&uJ&Aw@Y[r{Y}vK(B``6PJ"v;#/mL2KB);f#uE5BV<?i@mJ2FnLGgP9j, p#)K{1usZ#C2f"pKqqC#p7%`A2C|u#jIB6Z5n5A[(w4G?j;|q7vZIv`Yfl<sEP{@, 0rHE#}:nZH{42ZJ<|J%=qo@I/C{@%Jgq}pGpPsKGIpsvp;H(&w%1?VAfkGZilg98, 7/`521>=&EgwF5|{Hmjk.{(H<o;6>}0"V84%=g'@})v|8i@Mq8>#F@{GK4)}Ar&), g<uM"8gJYs{p[@&?2}qFIHj'n$Z915m7kivG@B)vd?g%mrEgJ$L.Gn;"#&w$@K@%, )5IBpkMrk$pV#2Iusg|Ms1klKG@$dj5MoK1q&=**,
!!!!!J2C,Cw,/&'&oJ0J')!!!!!
4HE /RACLE 4.3 ,ISTENER CONVENTIONALLY RUNS AT PORT )N THIS EXERCISE LETS RUN /RACLE 4,3 SERVICES AT PORT WHICH HAS THE current service name:
-,=<#%,PYgg,f#:?f;#<H@?#;,
<@?5<7A!$6,,,PYggf:?%,,,,,,-,'@?5<7A,2A<:",&6#<@?5,F@?#4;#, ,,,,,,,,,,,,,,,,,,,,,,,,,,,-,o545=#<,
<@?5<7A!$6,,,PYggf97%,,,,,,-,'@?5<7A,2A<:",&6#<@?5,F@?#4;#, ,,,,,,,,,,,,,,,,,,,,,,,,,,,-,o545=#<
0LACE THE FOLLOWING FILE TO CONTROL STUNNEL FOR THE hRICARDOv SERVICE ALTER THE )0 ADDRESS TO THE LOCATION OF YOUR 4.3 ,ISTENER
FEATURE: Stunnel Security
-,?5:,f#:?f;:944#$f<@?5<7AT?A48,,
;;$v#<;@A4,*, 0F)HPTg,
, A%:@A4;, *, 2.a))FHV, , A%:@A4;, *, 2.a))FHg,
, A%:@A4;, *, )12(FJaCwaZ)J, , A%:@A4;, *, )12(FJaJBCwaZ)J,
, A%:@A4;, *, B1/wJ'a)J'vJ'a/'J`J'J2BJ, , ?#<:,*, f#:?f%G@f:$;f?#<:;f;:944#$T%#6,
, `1/),*, 4A,
, 7#E9=,*, p,
, ;>;$A=, *, >#;,
, ?"<AA:, *, fH5<f#6%:>, , ;#:9@7, *, 4AEA7>, , ;#:=@7, *, 4AEA7>,
, ?A44#?:, *, PTgTVTM3PYgP, ,
h,E#;:!%<5?:@?#,?@%"#<;3,
h,"::%;3ff">4#GT6#f5<:@?$#;f"5<7#4@4=!>A9<!K#E!;#<H#<;!;;$!?@%"#<;f,
?@%"#<;*JBCwi&J)(Bo3Cwi&J)(Bo3JBCwi&J)gYp3Cwi&J)gYp3JBCwi&J)Pgn3,
´Cwi&J)3JBCwiVCJ)3CwiVCJ)3')&i&J)(Bo3')&i&J)3')&iVCJ)3,
´t52ZFF3toCY3tC))
.OTE ABOVE THAT YOU ARE CONFIGURING 4,3 FOR BEST PRACTICE ENCRYPTION WITH THE HIGHEST QUALITY PROTOCOLS AND CIPHERS HTTPSWWWRFC EDITORORG
RFCRFCTXT 4HE /RACLE CLIENTS APPEAR COMPATIBLE WITH THESE SETTINGS
.OTE THAT -ICHAL 4ROJNARA THE AUTHOR OF STUNNEL DOES hNOT RECOMMEND USING $( CIPHERSUITES IN THE HARDENED SET %#$( CIPHERSUITES ARE
MUCH MORE SECURE AND MUCH FASTER 2&# SHOULD BE CONSIDERED OUTDATED AFTER THE RECENT ATTACKS ON $(v /N THE OTHER HAND THERE HAVE BEEN RECENT QUESTIONS OF SOFTWARE PATENTS ON %LLIPTIC #URVE
HTTPSECURITYSTACKEXCHANGECOMQUESTIONSCAN ECC BE USED WITHOUT INFRINGING ON PATENTS ALTHOUGH 3UN/RACLE CONTRIBUTED THE %## IMPLEMENTATION IN /PEN33, AND USED GREAT CARE TO AVOID PATENTED METHODS 2ED (AT&EDORA WENT FURTHER IN ENABLING ONLY THE 3UITE " SUBSET OF .)34 %## CURVES FOR PROTECTION FROM #ERTICOM WHETHER THIS IS A SUFFICIENT COURTROOM DEFENSE AGAINST #RYPTO0EAK IS ANOTHER
FEATURE: Stunnel Security
matter: HTTPWWWTHEREGISTERCOUK
CRYPTOPEAK?SUES? "EYOND THAT IN MY PREVIOUS COVERAGE OF THE 3TRIBIKA 33( 'UIDE ;SEE h#IPHER
3ECURITYv BY #HARLES &ISHER 3EPTEMBER = ) WROTE THAT THE AUTHOR IS hADVISING AGAINST THE USE OF .)34 elliptic curves because they are notoriously hard to IMPLEMENT CORRECTLY 3O MUCH SO THAT ) WONDER IF ITS intentional. Any simple implementation will seem to work but leak secrets through side channels. Disabling them doesn’t seem to cause a problem; clients either HAVE #URVE TOO OR THEY HAVE GOOD ENOUGH $(
SUPPORTv 4ROJNARA HAS RESPONDED THAT THE QUESTION OF hSIDE CHANNEL ATTACKS ON %#$(% IS PURE NONSENSE SINCE BY DEFINITION THE LAST % STANDS FOR EPHEMERAL
there is no persistent secret here an attacker might RETRIEVE WITH ;ANY AVAILABLE= SIDE CHANNEL ATTACKSv )N ANY CASE (YNEK 3CHLAWACKS 7EB SITE ON THE SUBJECT HAS NOT ENDORSED ONE OVER THE OTHER SO FAR WHILE HIS SILENCE ON THE GROWING QUESTIONS BEHIND $IFFIE Hellman key exchange is somewhat unsettling
HTTPSHYNEKMEARTICLESHARDENING YOUR WEB SERVERS SSL CIPHERS 9OUR LEGAL ENVIRONMENT AND ENCRYPTION stance will decide your cipher string.
5SE THE FOLLOWING SYSTEMD UNIT FILES TO CONFIGURE STUNNEL FOR INETD STYLE OPERATION IF YOU ARENT USING AN /3 BASED ON SYSTEMD SEE MY PREVIOUS ARTICLES FOR A DISCUSSION OF ;X=INETD
-,?5:,f#:?f;>;:#67f;>;:#6f<@?5<7AT;A?G#:,