Cコンパイラーの基本確認

[yasha]

c++ t5.cpp -o t5 -s
: warning: the `gets' function is dangerous and should not be used.

Linux$B!J(Bcolinux+debian)$B$G!"%3%s%Q%$%kCf!"$3$s$J%o!<%K%s%0$,$G$^$7$?!#(B
$B$3$N%?%$%W$N%;%-%e%j%F%#%[!<%k!)$O$I$N$h$&$K2r7h$9$l$P$$$$$N$G$7$g$&$+!)(B

$B:#$N$H$3$m!"C1=c$K!"(B

pb = fgets( buf, sizeof(buf), stdin );

$B$K=q$-49$($F!"%o!<%K%s%0=PNO$r=P$5$J$$$h$&$K$9$kJ}K!$r$H$C$F$$$^$9!#(B

$B2r7hJ}K!!"%o!<%K%s%04X78$N>pJsF~<jJ}K!$r65$($F$/$@$5$$!#(B
man ld $B$G$7$g$&$+!)(B

[k***@gssm.otsuka.tsukuba.ac.jp]

$B5WLn$G$9!#(B

Post by yasha
$B:#$N$H$3$m!"C1=c$K!"(B

pb = fgets( buf, sizeof(buf), stdin );

$B$K=q$-49$($F!"%o!<%K%s%0=PNO$r=P$5$J$$$h$&$K$9$kJ}K!$r$H$C$F$$$^$9!#(B

$B$=$l$G$$$$$s$8$c$J$$$G$7$g$&$+!#(B

gets()$B$r;H$C$?%W%m%0%i%`$O4m81$G$9$+$i!"(Bgets()$B$r;H$o$J$$$N$,(B
$B:GA1$N(B($BM#0l$N(B)$B2r7hJ}K!$@$H;W$$$^$9!#(B

$B$F$J>o<1$,=q$+$l$F$k>l=j$H$+$"$k$N$+$J(B $B5WLn(B

[Hideo "Sir MaNMOS" Morishita]

Post by k***@gssm.otsuka.tsukuba.ac.jp
$B5WLn$G$9!#(B

Post by yasha
$B:#$N$H$3$m!"C1=c$K!"(B

pb = fgets( buf, sizeof(buf), stdin );

$B$K=q$-49$($F!"%o!<%K%s%0=PNO$r=P$5$J$$$h$&$K$9$kJ}K!$r$H$C$F$$$^$9!#(B

$B$=$l$G$$$$$s$8$c$J$$$G$7$g$&$+!#(B
gets()$B$r;H$C$?%W%m%0%i%`$O4m81$G$9$+$i!"(Bgets()$B$r;H$o$J$$$N$,(B
$B$F$J>o<1$,=q$+$l$F$k>l=j$H$+$"$k$N$+$J(B $B5WLn(B

gets$B$GC5$9$h$j!"(Bstack overflow$B$H$+$GC5$7$?J}$,8+$D$+$k$s$G$7$g$&$M!#(B

[Tadasuke YAMAGUCHI]

$B;38}$G$9!#(B

Post by Hideo "Sir MaNMOS" Morishita

Post by k***@gssm.otsuka.tsukuba.ac.jp
gets()$B$r;H$C$?%W%m%0%i%`$O4m81$G$9$+$i!"(Bgets()$B$r;H$o$J$$$N$,(B
$B$F$J>o<1$,=q$+$l$F$k>l=j$H$+$"$k$N$+$J(B $B5WLn(B

gets$B$GC5$9$h$j!"(Bstack overflow$B$H$+$GC5$7$?J}$,8+$D$+$k$s$G$7$g$&$M!#(B

http://www.ipa.go.jp/security/fy14/reports/oss_security/part2.pdf
$B!V8zN(E*$J%=!<%9%3!<%I8!::5;=Q$ND4::!W$H$$$&%?%$%H%k$G(BRATS$B$N>R2p(B
$B$,$5$l$F$^$9!#$=$3$G$ONc$($P(BC$***@8l$J$s$+$@$H(B

buffer overflow$B$r0z$-5/$3$92DG=@-$N9b$$4X?t$NNc(B
gets, strcpy, strcat, printf, sprintf, scanf, sscanf, fscanf,
vfscanf, vsprintf, vscanf, vsscanf, streadd, strecpy, strtrns,
getchar, fgetc, fgets, fprintf

$B$J$I$H5s$2$i$l$F$^$9!#(B

$B$"$H!"$3$l$NMm$_$+$3$NB3$-$@$C$?$+$G!"$3$&$$$C$?4X?t$r;H$C$F$$$F$b!"(B
$B4V$K(Bwrapper$B$r$+$^$7$***@H<e@-$r$H$C$Q$i$*$&!"$J$s$F;n$_$b$"$C$?$H;W$$(B
$B$^$9!#(B

[HASHIMOTO]

$B66K\$H?=$7$^$9!#(B

Post by k***@gssm.otsuka.tsukuba.ac.jp

At Mon, 13 Feb 2006 04:16:34 GMT

gets()$B$r;H$C$?%W%m%0%i%`$O4m81$G$9$+$i!"(Bgets()$B$r;H$o$J$$$N$,(B
$B$F$J>o<1$,=q$+$l$F$k>l=j$H$+$"$k$N$+$J(B $B5WLn(B

http://www.gnu.org/software/libc/manual/html_node/Line-Input.html#Line-Input

$B$N0lHV2<$N$H$3$m$K=q$$$F$"$j$^$9$M!#(BGoogle$B$G8!:w$7$F$_$?$i8+$D$+$j$^$7(B
$B$?!#(B

[EHARA Jun-ichi]

$B9>86$G$9!#(B

Post by k***@gssm.otsuka.tsukuba.ac.jp
gets()$B$r;H$C$?%W%m%0%i%`$O4m81$G$9$+$i!"(Bgets()$B$r;H$o$J$$$N$,(B
$B$F$J>o<1$,=q$+$l$F$k>l=j$H$+$"$k$N$+$J(B $B5WLn(B

$B7nJB$J$H$3$m$G!$(BC$***@8l(BFAQ http://www.kouno.jp/home/c_faq/
$B$N(B 12.23 $B$H$+(B 7.1 $B$H$+!#(B