From 113c95702aaab2b5653d6f297744f4406491be84 Mon Sep 17 00:00:00 2001 From: Cody Boone Ferguson <53008573+xexyl@users.noreply.github.com> Date: Sun, 2 Apr 2023 07:15:57 -0700 Subject: [PATCH 1/2] Updates to 1994/shapiro including possible bug Rename shapiro.info shapiro.md and make markdown format. Format fixes in README.md. Add try section in README.md. Add this entry to bugs.md for some systems. Specifically the entry assumes that EOF is -1 but this is not required by the standard; all that is required is that it is some negative number (see 7.21 Input/output subsection 1 in the standard). That's fine and well but changing the code to check for EOF breaks it terribly. I have added to bugs.md the problems and some tips in solving it (assuming it's at all feasible which is not entirely certain at this point and perhaps is not even worth it). --- 1994/shapiro/Makefile | 2 +- 1994/shapiro/README.md | 122 ++++++++++++++++++++++++-------------- 1994/shapiro/shapiro.info | 109 ---------------------------------- 1994/shapiro/shapiro.md | 118 ++++++++++++++++++++++++++++++++++++ 4 files changed, 197 insertions(+), 154 deletions(-) delete mode 100644 1994/shapiro/shapiro.info create mode 100644 1994/shapiro/shapiro.md diff --git a/1994/shapiro/Makefile b/1994/shapiro/Makefile index 784d635e5..1fb42498a 100644 --- a/1994/shapiro/Makefile +++ b/1994/shapiro/Makefile @@ -109,7 +109,7 @@ ENTRY= shapiro PROG= ${ENTRY} # OBJ= ${PROG}.o -DATA= shapiro.info +DATA= shapiro.md TARGET= ${PROG} # ALT_OBJ= diff --git a/1994/shapiro/README.md b/1994/shapiro/README.md index 6c59f1535..59d856847 100644 --- a/1994/shapiro/README.md +++ b/1994/shapiro/README.md @@ -1,62 +1,96 @@ # Most Well Rounded Obfuscation: - Andrew T. Shapiro - CSES/CIRES University of Colorado - Campus Box 216 - Boulder, CO 80309-0216 - USA +Andrew T. Shapiro +CSES/CIRES University of Colorado +Campus Box 216 +Boulder, CO 80309-0216 +USA ## To build: make all -## To run +[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) pointed out a potential +bug on systems where `EOF != -1`. The problem is that `getc()` and the related +functions do not return `-1` on EOF or error but rather `EOF` but the program +assumes `-1` (conversely when using the `getopt()` functions one should not +check for EOF but -1 as the functions return -1 not EOF but the standard does +not require `EOF` to be -1, just a negative number. However changing it to check +for `!=EOF` caused a problem due to the clever encoding of the code. See +[bugs.md](/bugs.md) for more details if you wish to try and fix this (Cody is +here and there working on it along with other things and will change this +message when it's fixed assuming it's feasible). + + +## To run: ./shapiro & -## Judges' comments +## Try: - This entry has many different levels of obfuscation, and yet the - source file is self documenting. :-) +```sh +./shapiro +^Z +bg +ps x +^C - From time to time, run ps and look at the new processes. +./shapiro_t1 +``` - See shapiro.info for more information in the internals of this program. - The file shapiro.alt contains a non-obfuscated version of this program. +Notice what you see in the output of `ps`! -## Author's comments - The basic theme (pun) of this program is: - - "This time (everything) is not where it should be." - ~~~~ - My entry (shapiro.c) is mostly comment, formatted in the shape of a - clock. If you strip out the comments and look at the code you will - quickly realize that the comments were the important part and that - the code does very little (see pun above). It writes (to stdout) - another C program (shapiro_t2.c). This is the first level of - obfuscation. - - The second program (shapiro_t2.c if you use the build/make file) - prints a clock in the upper right hand corner of your VTxxx/ANSI - display. - - Most of the surface obfuscation in the second program (shapiro_t2.c) - was an attempt to make it as small as possible. You should be able to - see around this with cb(1) and some more intelligent variable names. - Once you get past this you will realize that the third level of - obfuscation is a six member client/server hierarchy. - (See the second info file for a detailed description of the algorithm.) - - Lint complains about: precedence confusion, K may be used before set, - main() returns random value to invocation environment, value type used - inconsistently, value type declared inconsistently, function argument - ( number ) used inconsistently, function returns value which is always - ignored, function returns value which is sometimes ignored - All of which are harmless (famous last words). - - This may or may not work on non ASCII systems (I could not find one to - test it on.) +## Judges' comments: + +This entry has many different levels of obfuscation, and yet the +source file is self documenting. :-) + +From time to time, run ps and look at the new processes. + +See [shapiro.md](shapiro.md) for more information in the internals of this program. +The file [shapiro.alt.c](shapiro.alt.c) contains a non-obfuscated version of +this program. Note that this alt file is currently missing. See +[bugs.md](/bugs.md) for details. + + +## Author's comments: + +The basic theme (pun) of this program is: + + +> "This time (everything) is not where it should be." +> ~~~~ + + +My entry ([shapiro.c](shapiro.c)) is mostly comment, formatted in the shape of a +clock. If you strip out the comments and look at the code you will +quickly realize that the comments were the important part and that +the code does very little (see pun above). It writes (to stdout) +another C program ([shapiro_t2.c](shapiro_t2.c)). This is the first level of +obfuscation. + +The second program ([shapiro_t2.c](shapiro_t2.c) if you use the Makefile +prints a clock in the upper right hand corner of your VTxxx/ANSI display. + +Most of the surface obfuscation in the second program +([shapiro_t2.c](shapiro_t2.c)) +was an attempt to make it as small as possible. You should be able to +see around this with cb(1) and some more intelligent variable names. +Once you get past this you will realize that the third level of +obfuscation is a six member client/server hierarchy. +(See the [shapiro.md](shapiro.md) file for a detailed description of the +algorithm.) + +Lint complains about: precedence confusion, `K` may be used before set, +main() returns random value to invocation environment, value type used +inconsistently, value type declared inconsistently, function argument +(number) used inconsistently, function returns value which is always +ignored, function returns value which is sometimes ignored. +All of which are harmless (famous last words). + +This may or may not work on non ASCII systems (I could not find one to +test it on.) ## Copyright and CC BY-SA 4.0 License: diff --git a/1994/shapiro/shapiro.info b/1994/shapiro/shapiro.info deleted file mode 100644 index c81070fb7..000000000 --- a/1994/shapiro/shapiro.info +++ /dev/null @@ -1,109 +0,0 @@ -HINTS -~~~~~ -For the first program (prog.c): -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -This is a very simple program: - - 1. #include - 2. main() - 3. { - 4. int K,L,M=0; - 5. FILE *J; - 6. J=fopen(__FILE__,"r"); - 7. for(; - 8. (L=getc(J))!=-1; - 9. L>='J'&&L<='J'+15 && -10. ((M=!M)?K=L:putchar(K-'J'|(L-'J'<<4))) -11. ); -12. exit(0)} - -Lines 1-5 are basic stuff. Line 6 opens the source code for input. Line 7 -is the loop. Line 8 is read in each character in the file (placed in L) -while not EOF(-1). Line 9 is an if expression which filters out all -characters not between J and J + 15. Line 10 uses M to execute two different -paths the first just stores the character in K. The second path combines -the last two characters read in as high and low nibbles of a byte and -outputs them. In effect this is a very poor ASCII to binary decoder. -The last line is necessary so that make will not stop when it executes -this program. - -The second program is encoded into this format and then included (mostly) -as a comment. - -Notice that it is impossible to write this program while leaving 16 -contiguous ASCII characters free for the encoding. Because of this the -second program is mostly included as a comment. However, some of the -characters of the encoded program are also source code for the decoder. - -For the second program (time.c): -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - 1 #include - 2 #include - 3 #define o(j,k,m,n,l) {fprintf(j,a[k],m,n,a[l]);fflush(j);} - 4 char *a[]={"%c+------------+\n","%c+%3d %-8s+\n","seconds","minutes", - 5 "hours","%s\n","\0337\033[%d;65;H%s\0338"}; - 6 int b[]={0,0,17,14,11,0}; - 7 main(v,c) - 8 int v; - 9 char ** c; - 10 { - 11 char d[40],*e,f=6; - 12 time_t g; - 13 FILE *h,*i; - 14 while (--f && !pipe(d) && !fork()); - 15 h=fdopen(6-f<<1,"a"); - 16 i=fdopen((6-f<<1)+1,"r"); - 17 for(;;){ - 18 if(f){ - 19 fgets(d,40,i); - 20 d[strlen(d)-1]='\0'; - 21 if(*d=='0'+f){ sprintf(*c,"%s\n",d+1); o(stdout,6,6-f,d+1,0) } - 22 if(*d>'0'+f) o(h,5,d,0,0) - 23 }else{ - 24 time(&g); - 25 e=asctime(localtime(&g)); - 26 for(v=1;v<6;v++) o(h,v!=1&&v!=6-1,v+'0',atoi(e+b[v]),v) - 27 sleep(1); - 28 }}} - -Lines 1 and 2 have to be. Think of 'o' in line 3 as send message with -j,k and m as where, format and what. Lines 4 and 5 are all the text -strings. Line 6 is the offsets into the time string for the hours, -minutes and seconds. Lines 7-13 are basic stuff. Line 14 is the crux of -the biscuit. 14 forks off 'f'(6) processes each of which is connected to -the ones above and below it with a Unix pipe. It was too difficult to -recover the actual fd numbers for the pipe ends in line 14 so I regenerate -them and fdopen them (for use with the standard C library functions) on lines -15 and 16. Now we have six almost identical processes. Each of which has -two files open h and i (up and down). The only difference in each process -is the value of f (0 <= f < 6). The five processes where f !=0 are the -slave processes and f == 0 is the master. Line 17 says we are going to do -this forever. Lines 18 and 23 differentiate between the master and the -slaves. - -Lines 19 to 22 are the slave code. Here we read in a line of text from -i (down)(line 19) and remove the end of line char (line 20). On line -21 if this message is for us (if the first character is our number, f, -in ASCII) we do two things: -1. We copy the text of the message to *c which is really argv[0]. - If you are on the correct flavor of Unix this will change the output of - the ps(1) command to the string we just put there. -2. We send the message (not including the number) to stdout with - format number 6 ("\0337\033[%d;65;H%s\0338") If you can read VTxxx - (and I read books printed as ANSI/VTxxx codes for fun :-) you know this - is the sequence for: remember where we are, - go somewhere else, - print the message, - and return to where we started. -Line 22 says if this message is not for us (the number is bigger than ours) -send it to h (up). - -Lines 24 to 27 are the master code. Here we get the time and convert it -to an ASCII format (lines 24 and 25). Then on line 26 we build and send -each of the messages for the slaves. The message uses a different control -string for the different slaves. For the first and last slave the message -text is just "%c+------------+\n" (slave number, text, newline.) For the -other slaves it is "%c+%3d %-8s+\n" (slave number, number, units, newline). -The slave number is v+'0'. The number (if used) is atoi(e+b[v]) and the -units are just the string in the slave number position. - diff --git a/1994/shapiro/shapiro.md b/1994/shapiro/shapiro.md new file mode 100644 index 000000000..28b3e4eca --- /dev/null +++ b/1994/shapiro/shapiro.md @@ -0,0 +1,118 @@ +# HINTS + +For the first program (prog.c): + + +This is a very simple program: + +``` + 1. #include + 2. main() + 3. { + 4. int K,L,M=0; + 5. FILE *J; + 6. J=fopen(__FILE__,"r"); + 7. for(; + 8. (L=getc(J))!=EOF; + 9. L>='J'&&L<='J'+15 && +10. ((M=!M)?K=L:putchar(K-'J'|(L-'J'<<4))) +11. ); +12. exit(0);} +``` + +Lines 1-5 are basic stuff. Line 6 opens the source code for input. Line 7 +is the loop. Line 8 is read in each character in the file (placed in `L`) +while not `EOF` (usually `-1`). Line 9 is an if expression which filters out all +characters not between `J` and `J + 15`. Line 10 uses `M` to execute two different +paths the first just stores the character in `K`. The second path combines +the last two characters read in as high and low nibbles of a byte and +outputs them. In effect this is a very poor ASCII to binary decoder. +The last line is necessary so that make will not stop when it executes +this program. + +The second program is encoded into this format and then included (mostly) +as a comment. + +Notice that it is impossible to write this program while leaving 16 +contiguous ASCII characters free for the encoding. Because of this the +second program is mostly included as a comment. However, some of the +characters of the encoded program are also source code for the decoder. + +### For the second program (with time.h): + +``` + 1 #include + 2 #include + 3 #define o(j,k,m,n,l) {fprintf(j,a[k],m,n,a[l]);fflush(j);} + 4 char *a[]={"%c+------------+\n","%c+%3d %-8s+\n","seconds","minutes", + 5 "hours","%s\n","\0337\033[%d;65;H%s\0338"}; + 6 int b[]={0,0,17,14,11,0}; + 7 main(v,c) + 8 int v; + 9 char ** c; +10 { +11 char d[40],*e,f=6; +12 time_t g; +13 FILE *h,*i; +14 while (--f && !pipe(d) && !fork()); +15 h=fdopen(6-f<<1,"a"); +16 i=fdopen((6-f<<1)+1,"r"); +17 for(;;){ +18 if(f){ +19 fgets(d,40,i); +20 d[strlen(d)-1]='\0'; +21 if(*d=='0'+f){ sprintf(*c,"%s\n",d+1); o(stdout,6,6-f,d+1,0) } +22 if(*d>'0'+f) o(h,5,d,0,0) +23 }else{ +24 time(&g); +25 e=asctime(localtime(&g)); +26 for(v=1;v<6;v++) o(h,v!=1&&v!=6-1,v+'0',atoi(e+b[v]),v) +27 sleep(1); +28 }}} + +``` + +Lines 1 and 2 have to be. Think of `o` in line 3 as send message with +`j`,`k` and `m` as where, format and what. Lines 4 and 5 are all the text +strings. Line 6 is the offsets into the time string for the hours, +minutes and seconds. Lines 7-13 are basic stuff. Line 14 is the crux of +the biscuit. 14 forks off `f` (6) processes each of which is connected to +the ones above and below it with a Unix pipe. It was too difficult to +recover the actual FD numbers for the pipe ends in line 14 so I regenerate +them and `fdopen()` them (for use with the standard C library functions) on lines +15 and 16. Now we have six almost identical processes. Each of which has +two files open `h` and `i` (up and down). The only difference in each process +is the value of `f` (`0 <= f < 6`). The five processes where `f !=0` are the +slave processes and `f == 0` is the master. Line 17 says we are going to do +this forever. Lines 18 and 23 differentiate between the master and the +slaves. + +Lines 19 to 22 are the slave code. Here we read in a line of text from +`i` (down)(line 19) and remove the end of line char (line 20). On line +21 if this message is for us (if the first character is our number, `f`, +in ASCII) we do two things: + +1. We copy the text of the message to `*c` which is really argv[0]. If you are +on the correct flavor of Unix this will change the output of the `ps(1)` command +to the string we just put there. +2. We send the message (not including the number) to stdout with format number 6 +(`"\0337\033[%d;65;H%s\0338"`) If you can read VTxxx (and I read books printed +as ANSI/VTxxx codes for fun :-) ) you know this is the sequence for: + + remember where we are, + go somewhere else, + print the message, + and return to where we started. + +Line 22 says if this message is not for us (the number is bigger than ours) +send it to `h` (up). + +Lines 24 to 27 are the master code. Here we get the time and convert it +to an ASCII format (lines 24 and 25). Then on line 26 we build and send +each of the messages for the slaves. The message uses a different control +string for the different slaves. For the first and last slave the message +text is just `"%c+------------+\n"` (slave number, text, newline.) For the +other slaves it is `"%c+%3d %-8s+\n"` (slave number, number, units, newline). +The slave number is `v+'0'`. The number (if used) is `atoi(e+b[v])` and the +units are just the string in the slave number position. + From f2998adcab6561aa8f82aeb5d4347c910fae50dd Mon Sep 17 00:00:00 2001 From: Cody Boone Ferguson <53008573+xexyl@users.noreply.github.com> Date: Sun, 2 Apr 2023 07:21:14 -0700 Subject: [PATCH 2/2] Typo fix in bugs.md It should have said subsection not section when referring to the requirements of EOF not being that it's -1 but that it's some negative integer value. Also made worse not wore. --- bugs.md | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 100 insertions(+), 3 deletions(-) diff --git a/bugs.md b/bugs.md index ad3506e86..2a98c56c7 100644 --- a/bugs.md +++ b/bugs.md @@ -522,13 +522,13 @@ If you join the lines you end up with: If you look at column 25 which is the end of the word 'mh111' and you go down to the next row you'll see a 0 and if you go one row down another 0. This is the -buffer size, 100, for `u`. The column to the left is the same for the `t` +buffer size, 100, for `u`! The column to the left is the same for the `t` variable. Thus it seems that in order to get the generated output correct one needs to provide the correct input in comments or possibly by rearranging some of the -code (this was required to make the generated code compile at all when changing -the buffer size). +code (this was actually required to make the generated code compile at all when +changing the buffer size, see below). ### Important points: @@ -550,6 +550,103 @@ can cause a compilation error! Make sure that the output of: can be compiled and the output of that new program when fed itself can also be compiled! +## [1994/shapiro](1994/shapiro/shapiro.c) ([README.md](1994/shapiro/README.md)) +## STATUS: missing file - please provide it + +[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) noted that the +README.md file refers to an alternative version of the code that is not +obfuscated but it is missing from the entry directory and the archive. Do you +have this file? + +We would be grateful if you could provide it to us. If you can provide this +file you might consider removing this entry from this file as well but if not +we'll take care of it. + +### Important reminder to fix the `-1` value check for `getc()`: + +Cody wants to remind you that he fixed the code to not use `-1` for the return +value of `getc()`; this is important because `EOF` is **NOT** guaranteed to be +`-1` but rather any negative value. On systems where `EOF != -1` the program +would enter an infinite loop until the program crashed, by chance reads a `-1` +or was killed. See the README.md for more details. If you don't feel comfortable +changing it to `EOF` Cody will happily do it for you but otherwise go right +ahead. We'll credit you in the README.md file regardless. + + +## STATUS: doesn't work with some platforms - please help us fix + +[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) pointed out a potential +bug in [1994/shapiro](1994/shapiro/shapiro.c) on systems where `EOF != -1` as +the code assumes that `EOF` will always be `-1`. As the standard says (see `7.21 +Input/output` subsection 1) it only has to be a negative int, not +necessarily `-1`. The problem is that the source file's last character is a +newline (10 in decimal) and so on systems where `EOF != -1` the `getc()` +functions would not terminate the loop (but see below). This would cause a +breakage in the entry. + +However due to clever encoding of the code it is not a simple matter of applying +the following patch: + +```diff +diff --git i/1994/shapiro/shapiro.c w/1994/shapiro/shapiro.c +index d2da120c7bc4e251b7624859e48f47f188d398e9..e054a1ceb067b82bf37c07e5ce75e82be7a03b85 100644 +--- i/1994/shapiro/shapiro.c ++++ w/1994/shapiro/shapiro.c +@@ -9,11 +9,11 @@ + /*PPPPVPOQMQRPR*/=0;FILE/*TPSLUMWQT*/ * + J/*MPRPKPLQ*/; J= fopen(__FILE__ + /*T*/,"r");for (;( L/*KPUOWOWMUQ + LLOLMPULWLWL WLW LWLWLWLWLWLW + LWLWLULVOXP LLV LLLOLMPULOL +- MMNP*/=getc (J) )!= -1;L/* ++ MMNP*/=getc (J) )!=EOF;L/* + OLWLRMMQUL VOX PLLVLLLMQO + PMPYPXPNP MQL LVLLLWPSP + XPOQNQOPMQ LLV LTj*/>='J' + &&L/*LRPYP OQL QMQLLVLLL + OLMQVOXPL LVL LLVOe*/<= + +``` + +as doing so will cause `warning: illegal character encoding in string +literal` and the error `error: source file is not valid UTF-8`. Looking at the +file you'll see on line 4 of `shapiro_t2.c`: + + +``` +char *a[]={"%c+------------+\n","%c+%3dPRÒ<82>3·Âå&Â"2W6öæF6'Â"Ò<96>æVGW6'¢ <82>öV'7'Â"R2Çå&Â"Â^E33sÃ^E33³UB¶cS³<83>T2Ç^E33<83>#Ò·£<90>æF^G"¶ÕÕ³^GÃ^BÃ^RsÃ^RCÃ^R^SÃ^BÓ·£Ð^V<96>æ<86>bÇ2<96><92>æF^Gb·3<86>^V&^G¢¢^B2¶£°7<86>^V&^GB¶E^CÓÅ¢RÆbÖc³£@<97>ÖVöE^Gr¶£`<94>ÄT^D¢<82>Æ¢<92>¶£p<87><96>ÆV^F<82>ÒÒb^Fbb^B^R^B<97>^FW<86>B<96>^Bbb^B^Rbö&·<86><92><92>²£<80>ÖcFö^FWæ<86>bÓbÆÃ^SÃ"^R&<92>²<93>ÖcFö^FWæ<86><82>bÓbÆÃ^S<93>²^RÃ""'<92>²£`ö&<87>²³<93>²<97>f<86>b<96>²gvVF7<87>BÆB^CÃ<92><96>²C¶5G'ÇVæ<86>B<96>Ò^RÓÕsÂ^Es²£<90>f<86>¢BÖÓs^Bs²b<96>²7^G'<97>æFg<86>¢2Æ"R2Çå&ÂB¶^R<93>²ó<86>2GGöVGÇbÃbÓbÆB¶^RÃ^B<93>Ò§<90>f<86>¢Bæs^Bs²b<96>ò<86><82>ÆRÃBÆ^BÃ^B<93>ÒWÆ6W¶G<97>ÖV<86>br<96>²SÖ^S67F<97>ÖV<86>Âö6^VÆF<97>ÖV<86>br<96><92>²£`ö&<87>b×^S³cÇc³c·²<92>ò<86><82>Æb^WÒ^Scbb^WÒcÓ^RÃb·r^BsÂ^RF÷<96><86>R¶"¶e×<95>Âb<97>2ÇVV^F<87>^R<93>²Ó×ק  +``` + +when it should be something entirely different. For what it should be try +running `make clobber all ; cat shapiro_t2.c` or else look at the second program +in the spoilers file [shapiro.md](1994/shapiro/shapiro.md]). + +Cody is working will be working on this here and there but if you have a fix or +any suggestions you're welcome to provide it or them. + +Cody points you to the README.md file for what should happen when the entry is +successfully compiled (including no compilation errors when running `make +clobber all`). + +Another problem is that in the [shapiro.md](shapiro.md) file the first program +does not work. + +### Tips on this entry: + +Cody provides some tips on this entry: + +First: the comments are the important part of this entry. Remove them and the +program breaks. + +Second and perhaps part of the problem with changing the code to `EOF` instead +of `-1` is the `for` loop particularly to do with the bitwise operations, +perhaps also made worse by the seemingly gibberish comments. + +Another important point is that the Makefile compiles the program as +`shapiro_t1` so that the source code that corresponds with it is actually +[shapiro.c](1994/shapiro/shapiro.c). But notice how running `shapiro_t1` results +in different functionality than `shapiro` itself? The source code that +`shapiro_t1` generates, `shapiro_t2.c`, is what is compiled into `shapiro`. # 1995