ÿØÿà JFIF 

  
 
  ÿÛ „ 
 !.%+&8&+/1555$;@;4?.451
4,$,44444444444414444444444444444444444444444444444444ÿÀ  á á
" 

ÿÄ   



           
 ÿÄ ? 
    
 !1AQaq"2‘¡±ÁðBRbrÑá#‚’¢²3S CñÿÄ 
 

             
ÿÄ ! 
 
 
       
!1QAa‘2ÿÚ 
  ? 5˜Z¯V¦cø)›t/? z¨±>Õ5€¶‹Á¤·¼z¼Ü¬+ñ®v¤¨_ˆR­BFn©—˜ý®ç̝P8gýt·ÉSTŦˆìät?þé¼íìN/Þa)ì–í6ô…
Ï¿øÃj´¿KÇü]ÿ ªô¹-eKànëÕHTx}ýSÜ›ÿ ”7Ø×&µ<¦  ¥ÑO¶[Ù¯ä¨ÞÃÿ PZ-¬;#õ|•
oaÿ ©CìÞz3˜öː/¤­ñTûIØ}š^   mÓ%ªxˆ¥ÉŸu=Z+ISe¿45™¼u;ú&WØ÷€æßQ™®{|
íx*TC“#ZŠìZ§²‹ 6pv…³¿¡äª*áZÐ%ÒOáˆo"x«OHk
w±æ+¬V(kMúŸ5Vö«$ ÁrÏbàb57/luR ¸ÑÛj Òµì`Ðœq­û žICÀ
Ê•©4€Âcà¨Ï€O´<èÐ:›ù(Ë^L8þ‘ÍÌ#¸Ð_Ì©ÙK(Öz 4¬û+¸;ü’V’84‘¬ÃŽ:[â‡ÔÌáõp¢~§ªlæ£ö{®G>J¼"°‡7¯ÆÉèßû ‹É‹§ÁòÃýâßî
^ƾÙõ‹×óH#«LP½ïX=xÑÍ$|W?•~•îëÔ©ª‹
{ÝT…Kÿ ”hûâá)J*ö˜–ÔU;iÇ€/ ÆþjóZ\ýwØ=Ìm
ºèËL9 ýè
Æð/¨’¥öo=nË.%Îì   ŽÕ¯È|{Oj²ƒE6e/ßdÄõ²Ìâ1O®ò×TsəԸhOMýíMˆ¿¼H˜l²,7Â¥#MF/Úf°Ö½± ¸–dr‹NýÊ íjqx{œÉ ä-È    ¦
øÄër¨q°ð
†nцýÑÄÆ’mä…n<0È™;ÁÝá¯ÁZƒ7FÀmì­ É&9ˆîéi¶ùN§Y•ÃZãAâ?•‡©‰ , ó¾IŸŠc1 4â&y­&pŠ­6;M À 0¹qç»p.á …ŸÅáK@<u %Ü6ÓtIÌpÓr»söfeÁ0O…­´Kƒ&ñ™\©<+,~)‹
ºHÐ*×µ&†ž‘Æ÷ÚŸ
1ßjC5Oh´‡›

Ø×ë æâ“Þà

ÒT]§n{ºöB³ ¦ ̹Â8Êï¦MÉ<„¨s¹¶ì7Ì”æR$Ncà! /éþäRM÷Gƒ¿É$
¦oà>%6·y6ƒ‰3?”úºŽ‰éX5ªPT §µ!=Mž«Ú½‹ÅgÂSâÉaþÓoö–¯ÁÔìR>5éÿ üs¶ÆUcÌ  kÇR
]ÿ ù¬¼«VŽ;Â|‡~¢¦”ÏÅ°æ
{L™Õ°Óv¹ò¸írŽ¡×¢CÃ!íVÕ {¶»sŒNPg/
"uÕbkm²“$ďå¿é¹§°½æz¯6 †s¿!s–wÚÝ“™Œ°.ûj>·+™Òa…©Œ&rÝÎtÛë긪Ît’LAVp%c Úý[ÄzJ¾ÇàXXç@˜ó<êL]·T˜¾¥1Ó©V‡g´æ½¦Ý@¹óø!_@´ÞâSÁ —S3™•& ]@JHÚý©ZŽ €×æÔr»Áf!‡yÞ4Mv*èÓã_{‘åóUuљØ«Oïé*®EvÑ
Œ÷‡U \"㪒ÍK+À 4“M¡ï:0¥5í!'<@î´”>Ç»&Z–ïCCV˜Ì5Šo&îhè.žû
|ÓK©h$s6KìŒëã)¹hI¦GïOåóI;ììü#É$Š0…Ææ¥TØ.5­¾gn´ “ÂÖ\:hœ89G)J@„}œ:’Ò{/Š"¦_Æ×7Æ3VÇŠÊa]ÚŒÙ€Ä–=®uÁßâACZƒ§§£Qnâ:«,×{tyø¬iÛcœÜÄ€H½ÄÍCk´÷šß
.W'b¤Íåh]÷€=,Žv×cÚEÚHXJX¶îo¨FÒtèöŸ>ªª6[J®Fµ£sGÁeqõfe\íjÒÐïÄÐGˆe1Ø‹.Ø”‘Ëuø
Y­ˆÜŽG|zùªüMpDnQWÄ”%JŠ™)â*p@Örš«ÕT2Ð%ˆG#ª„
·¤!°ŸOTÂT¸aÚ%4&h™LµšØüÐ.F¿²ÐÞ_Ç‚¾ÅÃaÜ÷09Æ 
q€öy˜v‡85õN÷]¬äѼóS{°_MŽ¬úÔ#°Ç¸0åÞè2ëôPcvÆw9®ií1Ä8F™˜à‰´+‰Ik1òÝ7“Ñ×ÒsÝ\x‚h`ÞÑ`ó"|µEcý£n˜h`}GÞ  !±ù²Ápü²
ß6
0ïi󜵩SÈÇ7˜-ÕURO˜¦´f$ªž-Í6(œ}<„ éc øs]ŽŽ„*—¾
ìdŽ„)méª\¿êÎIg¾ØÞ~I#C/¼¼´EÁÈŽi8“©õådô·>euä ƒ'Ê×लR1ÉJE1ÐAát`t;ÇР%Ý<‡¥„ÍÆ`×Oyó)õiI€ñQaŸ4Ûù\áàaÃÔ¹HÃu¹*k€¦<„eS‡&õÏ
B!ŽhüÞ`yj}mªf×\¿
Ç~æ­9‡û\՞Ǖg²1Žû5V7 !àöšm°
c`ܬøÇìµÒ'P"?…´Ö,"§^•õŽ¨sÔ)6˜sæéÍR¼
ò|Sl”‹7 nPW

Gòú÷½§O¯‡„l¡kSÞŒr½PÊ@æ¢pŽ-mÿ #Ÿ˜Àº¶Áä¦;ïÔæ$1££`“Õ>„—·ž)ß
ð
³ñ#Ï Ô$¶œ‰ÊE‹À;÷º
¯«P:Ñ”8–IÊtpÞ3ª“>ê“þës4ò2OÏÕ­±zô†Õ§‰.÷ä¸;¿˜“'œ›žª}«Œ{ª±Ì 9ÔóÞÕ‡0
$íWV3Üì¬
—@kÝ4@¿r¼±½¬™›?øØæ´'Áé®CË3-g$˜ö‡×auÚi´Žp/êÛæF›Ú2v‹ã¿¿,nB1̨ƃqÞa5͝@&Æû“él÷ \C²½UÍc ¯k×¢U
ÖéQå™—-r    wô ÞÏ<Ò=&=ÿ Ôê Òêˈt,i—;LîÜ á¸*ÚÃ1$êL•LÍ <É)ýÐà’
;F™{ƒ™˜€&'}‚ãÄK`¡ÞT@I;®žZóè‚s’7®°›+§O­Åq©é»²9<Ô
J ¼9O’HL»Ùïì¸rk¼Ž_ý‘TŸu[²ßÚŒ·ü÷B%¯E ŸÔX5êO´Ç•€’I0 É<mÆÈJoúáõóQâØòÙaÙt:  ·=|Ôaz]a1cÉŸ1
4˜à3΍}GFøí7/B«vεŕL=Ðr1ÕšnwH›óÞ¢ºö{)´4€æZç^ÿ yÑ:_([¿ipqQÊ^âÆe;»½“¦º|¢ÀTçèrú1”óTÃ’u¦CG¤ ¡
Š­7ë

·i“¿z»n
ö¼±ù^ö<‹çu7¸ÈlvZðÛAUXje•
dLÞH ÚosÇr`È™‡pÊeÇ4@x7´)ö†Ótœ~i‘Ï[x@äUÃæ­m·e´x
°t¸·²5'žªža   =ÖÌåzϘ'-´ˆpž3§ò‡k  Ý'‰ýÑï¦3ºdè“{eiÔõNkîšECEΠ¥ÃT9ãqÃâŸîɐ8z \?€    >JX` 
ñ¹õ%;µŸD‘«´€àwÒ™UûئžÖö\×®×´8 ½‡ºÐÆÓ§?Àkmœ=;d5*@-ì0F Rªýš[Ü6âö̃ڸr*KA9· u*µæ£?U¸Âêí†8@¦X4 e-ò„0s{ HâUpU?¼mñRa°®a%Ð'tÉ×’\¾ÊÉ]t›h>·(Ë@R¼¡Ãt h}’O÷au<+nT…Ö…MӐ??Óe95 q>í/;&JSû °¯ÊéÞøƒ*Ã2½Ài&:nôUl=¾¿5eˆ3”ñc|Ú2V”>„»&eE;«ÚäC
p¢Ûúy 9š[ŒÌx¼擼A&DåÒ¯ˆ¤ÀÌ;"˜ÏQä¸åhÊ}Ûq«Û0WžÒ|»€ø®öCm5•\ÇÀ§Pe3£]0ÃàLDÉ‰1øªxjgwT‚÷¿LΨK‹›ùs—xˆÜ±µ
kæ¸f‰‰ÜGk/LÛØ6d9ò¶ùA{ƒA3š/¬D¬khÓk‰`˜"㯒r¿±Óã jx‡°e}<Ñø\3y:'À•/h½Í€Ç4~g ?Û(¼]v‘ªlKÎâ~?O‚W%{Ì:“'©úNq¾›úo(X’¥¯ˆ
nFê{Ç€ü?º'ë
ø‹ì
Þ09ŒÌç9Æ —ËC`j@ÓÄ(+a‹un¸#ÂꟋ{K`‘ÑÍÍ'à´»/Û,KW;Þ4²þð ï Nm|~fGÏ(…³Ã)«1ö­Õ
¥‡¨©ƒÃ™ü-s=à=U66Ï«Ýc蓦W¹íž®›nÔ%êÇìŒ<#Ü×84ån®Ð ÒåOC`  ñânÑs‡¢ç 1õ%Îhì½Ã½® e:ݼUZo
™`  
ÅZŸŒÊ«ê1ÏÄo$q¹Þ€©ˆhÐÉä¯ñ[!…Ú˜àJ:x2$Íß&PåT£6ç—
‡Í*4Ýšçjÿ ‰É nófÐ ó(L5C•åÆ\rMÒ@ò
}y-W}™üýVù—ú¢=Ù”c®‘< M ž
´Phr¦©TD ‘ù.$´÷O‡‘V2Æò.=IUŒ=ž‡â¬i™aþÓåÙ?òUø'ØÖ•.~* šTŒ!•-×áºTâ®ä#õü'´ eýlYÅÓeÕKÂrT"CÚ@u!Óxƒ{š3€}1¿(r}%«nËamjÑ%ÑNEò
v  ˜à  σöK³,*º.àzù¨™Ó ÚçâU¦*¿ 9{%Ö¹ njûdaXöb)  kÛƱûÓ\°M7ˆÂ=û›ç¿Ã‚­V»Cg–8ÙêE-j)k$º`Ã-ùEýeBÆÇ]c¡°ñty&Òd0nõ'¡W+ƒ*|–ø<K\%¦cÏÄ#N,Úú‘¤òÒÛõ ’¶§‰Ì
ú•dçb31Ð\7‡ëÚw82
‰KÝkÚñ'¢Ž…[&¼ÌAÔzHàP *اoßreÁY¥Ñ¾ãE|&QbKg]ã„þê*b;R³Öi‹  ±î$£ÈTm¶k÷ˆ
¦»Ù¹i¦¨6 h%Á'Ú
J   \F±â+‹b/Å9ñå5Àë­nˆRv«¯#„&î„$º’@:‘Ôrø+,àq‘秬*Úg´>µFa\GQªEAÔp5\Ǽ·¼Ç8·õ -â§Ú[
‡
uZeÖ 3}×d'+¹:ð+K†Û®s!Ï$úe€<Û”x)1»a­¡LC]¸µík…ÚàA»AYº{†ªS[¦5HÒ7ù
--,ísòDØ€èk   ÞÀîÜò@â(  ËNˆë›4ô½•/¦o‡€Û7
ê•ÆêòðÜy
'Án½µ á˜ݦ  ndeo…[ì¶Ê,¥R³Ä=À±—–ß;£™´ñSâ*g§”ïaið‘Jå~™ÓÞß³Õ¢»8x埒²52>AÊb&-÷\7´éÄù€T˜,w;3{ï˜k…à¹ÄqÀ«œ{
€\
ˆ¾[´¨јr &Úé„Ívˆ±8†¿]|¬ņ4I×pÞS1ÈÖz‰#Ìv‡G!YNògñ:màTz¢Ý1ô©^O=~ë|5Bã™ç•¼µõ•bÆ@úÕS¬ÈŒ#¬zünrŸ
û”
Z²•ï›èðV"ÁHÚý©wÝ €7¼Ìu1hÑa3Éä û f$o¿É ™Ú›ÝçnpÒ3äÌ3†Í§,Äï]$‰/pê†«À¼
¸e9­Æê_C]žƒ·ý·frÁN«,E=›Çq
-‰öŒ:aÏ¿±í&£Í:-}
84‘ÿ eƒQÑeëSsuiA
³g㟥ú£?ÿ ʼn*”“÷aühe:ÊWa@ÒÞk±eØ]
F Ô—r.åä˜@ö¥ªZoÐýYL·¥S²G/‡ñ
<~*ZÆ´è>JlòàÛƽÿ 窘ìGN¢:I®KšJp/`íIÁÀõ#Ä-€ö­šµŒoF4|ÆQØÆ@Ì|£Ô…¢À{9˜è½Üó›€ôYÒÎYsið;ís¤€à²ˆ‚4qÉVŒI$  ‰"°   æµ8cXGjœˏ¡Aâý•ËÜ¢ûïe·çLx']á"oÅÎê3¯Ç—¹”ó0nå‚âg{Œñ>
S´˜îè°g238‚ãköÝfÚd´6Ò€;ò÷±¢™¼›º¢Æ'¥Ðx'e¬ç
]bÈÆV¢ó‹kýBO
ðÊâ$Ÿ!×T
3Mýמ
žìٍàÌü‘8÷€àæØ8æ©6‰©L´«…oãpð„~Çk‰!ñ;‹”ÛžÍ àž±z Ÿôû øŸÝužÏ;ÿ #|u6™Þ¬ÚˆÐõA4¶â|ôl|Ê2ŽÇ¤ÝÅÇY.<#Aí.k§hóF‚”Y;
M½Ö4hŸ4&›­¿tès´%FìL¥£Ãk‰ÇT¤haÁ¤ÚxfÉ`ÑìË›>i 3t‚:,–+^÷´–{Û–Nxi"x‘Ûg
î¨>¥Õ܁ùZH,2Û“:8xÊ¢Çí9.É-Ìâã-=çjwµS˜dütžçwýGòú®®ûº_ˆýx$–¡ãøO
EÚÛÏ÷R„×w+3£Á£öUMyR²¹âŒ°š›¸Ñãò9§Ó_Dl+Ùßc›úšGÅÌc†Ž!Ko=¶.‘Îÿ c²(2®V mª.ÿ ¹B›¹å ù„öŸSV>™ü¯$y:G¢Z×àøúdî¹û­·ýÇ´:•c LÍõi_‹ö+ÎæGÊè>OŠ•äž´§Þ{X}¨1ÚTc›»Qþ•êô°t¿OP?eæ~É{5]•ÙR£r5†nZ\ã@
&îJõ ¾àC°þV>fé¥/ü5ñÊIº_é5;e­h<@
Ä&æÃëE%;X,ÒãÆÞ`Oò¦kŸm#˜!ÀyÄ¢|
óLšò¥Ä`
¶R=|ÈCâh5ò3DˆïF†ðÒ#ÅìÛœ?¸yhBãœí
ZxßÎÄhºRK„`Þödvײ™ÀÈÑÒgŒuYw³%†ƒÓzõ ÖÏp‚dH®¦A´ù§»ÓÇMæ~)ˆð‡û:ù&Ä •vGD´À 
n
Ý
‡¼Ö8Fö   óáà£~Ë¥x`oK|Ä?fxiØü%pìR>éò+Û±éÎ>núlFŤ'tq8LZÏvÃ?„¡ß±È⽆¯³íü@x|PöUäèØã¡ð‚ŒAìÏ"vÍwóŸÍ{ ý0.z    È•Ö{,N¡£¡ŸKÕÙž>Ýœþ ÍÀ<n^Àïe€Þgn¹”ÜiQê
9Ú±‡„è]ËA¿‚MJìiÓxŒn-ÄS6!ÓæÑû*jÎWøìšÇ뙦gj~+?\,Ö7ÁÕÊ”G™q6TF)óCç<ÓšÂUé†gW=àà“hóR³ÊQì<!÷ÇpR1¯u„De,è­vvâDß~žHå‰ú£Kìní¢ÐçÅÄÅ¥Ü÷
±ÃìÇžûƒz\þÞ¨-•‹
€

¸+¶n¿^
?†[ÖWóÒX¸,0Ø:l?‰Âý«ÿ ·Dc+fÔ[ƒ›ûªšx«kæž1KI…<#'nž¶\±íÎ8¤ìK@’@J¥v)º[Ž±Æå´¼
½Ý¡ç¯ÐO¥ø®è•Óȱ߿wša©“œt‡4îyªœ&+1ÏØ:‚æƒ=/ꎔ`hm
“=©‹]°g}ì€DgUƒ8¤qCˆãáÅ,‡Ô¬ñ10HÑDÂbáÂÿ Œ»v·:uòB6»áp‰>°<×EA!Å‚D™IúOÍ
¡>ôG}Â`ÍßkÜL™Ž  Þð™
{IøF²
¹òQ3&!ÃÂÞz.d&Ï-sH¸,Ôõ˜ŽP€
77ˆÝ¼ÊëÜw   =cÕ
Ú,ØÐ5ÎYÐ)ì´öœgŒ[¤
ßv㙑8心>h]§µháYš£²ºÑ.{Ï7Sð•?´~×SÃKýJÛ˜
™Íäiúu<µX¶1õ^kâçIÑ£sZ4h>j*ÔšD:4­¿_ ÷¸
Õxæÿ ¸?Mù _•­ÊÐ ä ÷ý ÑwL
œ­ïnTkÛUÍN©ë:¦fV ¶ÜÔÜMªÅâA½–¿R×TXš-%iTÊT•‡Ù‚JôϐZxWÑè‰f‰òG º
×Õû2aZ7OU3[“×AT–ÞŒ…-‘¤”Ì 
ì&(ˆ¿­•ƒkï’:ðY¦W‘Å)“†‘˜³Åtcø˜ñTÂwÚÇ4
|üLÇªí–v-
qˆèU
qPE.†â‘˜µ Æ,ÐÅs]8¾„oúÑ i>ÜxxÈó)ƒ ´æÁâØ$À‰vžŸf$Ž|ãw;ÀÁIJ»b`
{¦Ó¤Ú$©YÀ‘n@Óïž«9J¼êG   m¤
ܯ¹ÌW4€ÐÒÅÛ‡#褕Ÿn-?í|с¥÷Ú¹¬'´ÞÜ9ÓK`hê£SÄSà?7—Wí_´…óB›»:=Ãïq`<8ñÓŒÑlú2d¬ê³£hÖ[l|$vÝro~'R®‰§°ñmY ͧäP
|PUª¹·:3Œ[Û{Xÿ ºâ@‚W–Äé u‚ ¯´*=íή.pûÒdt @
G‰¬ s¸    ëÉücr ÞæѨÊ@>¤¢Ö±.Þ'¯°ÌME[YéïĵÂCå½
Ué©Áû'Ê9%eÔðNU”ë‘ÌsD3/®+UI˜9h.WC”
빓$#:pz:YÓ ¿xž* ³$Í +$kñAŠ‹†¢
Uê>¸)_š¬÷©ßAÂÔb9ÇU ¯¾
á•9¯ÏÏ÷O÷¼¼Fähal1‰3Ì[Ïr•´UCksNÐ]R‘¸¥H+§Šé†c©vÖÞ0iÓ76s†î!§=ß
¼~Ô'°Ãmäoäš³ªøi1úÉ)³yV8CLÄØÁ‘WYïi€H6ÖÑiámø^ÈY´°Ñ7¥Û*—Ñ©L«Qƒï—Ùrÿ ›£Ð*š¸ˆL©ˆ$ˆ ÷¾D§9È®«qbqC)–ˆïv´çñsÑVT­Ø, <àïºÀO«Jý·õ 
àfPìð  .wFšir´þ’2_Y
*Æ€x\«
ì€9š@ Ž|F⇥ˆkZ@hÖÄ0t¿-<“‹qµ¾*ZL¤Ú)&BJpÓF5=$„at*Zš$’ÑtdûÝRI1    2Ž‰$€$I$#‰SÞ’H
ë¬ï;Á$¡t$’`<(ñÇt)$‡Ð.Êf¢X’Kt=Éé$‚ˆªè¢oÝëòI%Rgcª÷ŠyI%¡‰ÿ !ñ)´õ $¤ Ô’IIGÿÙ# -*- Mode: cperl; coding: utf-8; cperl-indent-level: 4 -*-
# vim: ts=4 sts=4 sw=4:
package CPAN::HTTP::Client;
use strict;
use vars qw(@ISA);
use CPAN::HTTP::Credentials;
use HTTP::Tiny 0.005;

$CPAN::HTTP::Client::VERSION = $CPAN::HTTP::Client::VERSION = "1.9601";

# CPAN::HTTP::Client is adapted from parts of cpanm by Tatsuhiko Miyagawa
# and parts of LWP by Gisle Aas

sub new {
    my $class = shift;
    my %args = @_;
    for my $k ( keys %args ) {
        $args{$k} = '' unless defined $args{$k};
    }
    $args{no_proxy} = [split(",", $args{no_proxy}) ] if $args{no_proxy};
    return bless \%args, $class;
}

# This executes a request with redirection (up to 5) and returns the
# response structure generated by HTTP::Tiny
#
# If authentication fails, it will attempt to get new authentication
# information and repeat up to 5 times

sub mirror {
    my($self, $uri, $path) = @_;

    my $want_proxy = $self->_want_proxy($uri);
    my $http = HTTP::Tiny->new(
        verify_SSL => 1,
        $want_proxy ? (proxy => $self->{proxy}) : ()
    );

    my ($response, %headers);
    my $retries = 0;
    while ( $retries++ < 5 ) {
        $response = $http->mirror( $uri, $path, {headers => \%headers} );
        if ( $response->{status} eq '401' ) {
            last unless $self->_get_auth_params( $response, 'non_proxy' );
        }
        elsif ( $response->{status} eq '407' ) {
            last unless $self->_get_auth_params( $response, 'proxy' );
        }
        else {
            last; # either success or failure
        }
        my %headers = (
            $self->_auth_headers( $uri, 'non_proxy' ),
            ( $want_proxy ? $self->_auth_headers($uri, 'proxy') : () ),
        );
    }

    return $response;
}

sub _want_proxy {
    my ($self, $uri) = @_;
    return unless $self->{proxy};
    my($host) = $uri =~ m|://([^/:]+)|;
    return ! grep { $host =~ /\Q$_\E$/ } @{ $self->{no_proxy} || [] };
}

# Generates the authentication headers for a given mode
# C<mode> is 'proxy' or 'non_proxy'
# C<_${mode}_type> is 'basic' or 'digest'
# C<_${mode}_params> will be the challenge parameters from the 401/407 headers
sub _auth_headers {
    my ($self, $uri, $mode) = @_;
    # Get names for our mode-specific attributes
    my ($type_key, $param_key) = map {"_" . $mode . $_} qw/_type _params/;

    # If _prepare_auth has not been called, we can't prepare headers
    return unless $self->{$type_key};

    # Get user credentials for mode
    my $cred_method = "get_" . ($mode ? "proxy" : "non_proxy") ."_credentials";
    my ($user, $pass) = CPAN::HTTP::Credentials->$cred_method;

    # Generate the header for the mode & type
    my $header = $mode eq 'proxy' ? 'Proxy-Authorization' : 'Authorization';
    my $value_method = "_" . $self->{$type_key} . "_auth";
    my $value = $self->$value_method($user, $pass, $self->{$param_key}, $uri);

    # If we didn't get a value, we didn't have the right modules available
    return $value ? ( $header, $value ) : ();
}

# Extract authentication parameters from headers, but clear any prior
# credentials if we failed (so we might prompt user for password again)
sub _get_auth_params {
    my ($self, $response, $mode) = @_;
    my $prefix = $mode eq 'proxy' ? 'Proxy' : 'WWW';
    my ($type_key, $param_key) = map {"_" . $mode . $_} qw/_type _params/;
    if ( ! $response->{success} ) { # auth failed
        my $method = "clear_${mode}_credentials";
        CPAN::HTTP::Credentials->$method;
        delete $self->{$_} for $type_key, $param_key;
    }
    ($self->{$type_key}, $self->{$param_key}) =
        $self->_get_challenge( $response, "${prefix}-Authenticate");
    return $self->{$type_key};
}

# Extract challenge type and parameters for a challenge list
sub _get_challenge {
    my ($self, $response, $auth_header) = @_;

    my $auth_list = $response->{headers}(lc $auth_header);
    return unless defined $auth_list;
    $auth_list = [$auth_list] unless ref $auth_list;

    for my $challenge (@$auth_list) {
        $challenge =~ tr/,/;/;  # "," is used to separate auth-params!!
        ($challenge) = $self->split_header_words($challenge);
        my $scheme = shift(@$challenge);
        shift(@$challenge); # no value
        $challenge = { @$challenge };  # make rest into a hash

        unless ($scheme =~ /^(basic|digest)$/) {
            next; # bad scheme
        }
        $scheme = $1;  # untainted now

        return ($scheme, $challenge);
    }
    return;
}

# Generate a basic authentication header value
sub _basic_auth {
    my ($self, $user, $pass) = @_;
    unless ( $CPAN::META->has_usable('MIME::Base64') ) {
        $CPAN::Frontend->mywarn(
            "MIME::Base64 is required for 'Basic' style authentication"
        );
        return;
    }
    return "Basic " . MIME::Base64::encode_base64("$user\:$pass", q{});
}

# Generate a digest authentication header value
sub _digest_auth {
    my ($self, $user, $pass, $auth_param, $uri) = @_;
    unless ( $CPAN::META->has_usable('Digest::MD5') ) {
        $CPAN::Frontend->mywarn(
            "Digest::MD5 is required for 'Digest' style authentication"
        );
        return;
    }

    my $nc = sprintf "%08X", ++$self->{_nonce_count}{$auth_param->{nonce}};
    my $cnonce = sprintf "%8x", time;

    my ($path) = $uri =~ m{^\w+?://[^/]+(/.*)$};
    $path = "/" unless defined $path;

    my $md5 = Digest::MD5->new;

    my(@digest);
    $md5->add(join(":", $user, $auth_param->{realm}, $pass));
    push(@digest, $md5->hexdigest);
    $md5->reset;

    push(@digest, $auth_param->{nonce});

    if ($auth_param->{qop}) {
        push(@digest, $nc, $cnonce, ($auth_param->{qop} =~ m|^auth[,;]auth-int$|) ? 'auth' : $auth_param->{qop});
    }

    $md5->add(join(":", 'GET', $path));
    push(@digest, $md5->hexdigest);
    $md5->reset;

    $md5->add(join(":", @digest));
    my($digest) = $md5->hexdigest;
    $md5->reset;

    my %resp = map { $_ => $auth_param->{$_} } qw(realm nonce opaque);
    @resp{qw(username uri response algorithm)} = ($user, $path, $digest, "MD5");

    if (($auth_param->{qop} || "") =~ m|^auth([,;]auth-int)?$|) {
        @resp{qw(qop cnonce nc)} = ("auth", $cnonce, $nc);
    }

    my(@order) =
        qw(username realm qop algorithm uri nonce nc cnonce response opaque);
    my @pairs;
    for (@order) {
        next unless defined $resp{$_};
        push(@pairs, "$_=" . qq("$resp{$_}"));
    }

    my $auth_value  = "Digest " . join(", ", @pairs);
    return $auth_value;
}

# split_header_words adapted from HTTP::Headers::Util
sub split_header_words {
    my ($self, @words) = @_;
    my @res = $self->_split_header_words(@words);
    for my $arr (@res) {
        for (my $i = @$arr - 2; $i >= 0; $i -= 2) {
            $arr->[$i] = lc($arr->[$i]);
        }
    }
    return @res;
}

sub _split_header_words {
    my($self, @val) = @_;
    my @res;
    for (@val) {
        my @cur;
        while (length) {
            if (s/^\s*(=*[^\s=;,]+)//) {  # 'token' or parameter 'attribute'
                push(@cur, $1);
                # a quoted value
                if (s/^\s*=\s*\"([^\"\\]*(?:\\.[^\"\\]*)*)\"//) {
                    my $val = $1;
                    $val =~ s/\\(.)/$1/g;
                    push(@cur, $val);
                    # some unquoted value
                }
                elsif (s/^\s*=\s*([^;,\s]*)//) {
                    my $val = $1;
                    $val =~ s/\s+$//;
                    push(@cur, $val);
                    # no value, a lone token
                }
                else {
                    push(@cur, undef);
                }
            }
            elsif (s/^\s*,//) {
                push(@res, [@cur]) if @cur;
                @cur = ();
            }
            elsif (s/^\s*;// || s/^\s+//) {
                # continue
            }
            else {
                die "This should not happen: '$_'";
            }
        }
        push(@res, \@cur) if @cur;
    }
    @res;
}

1;