Index: unarj-2.65/sanitize.c ================================================================================ --- Makefile +++ Makefile @@ -6,8 +6,8 @@ CFLAGS = -O2 -Wall -ansi -pedantic -DUNIX INSTALLDIR=/usr/local/bin -unarj: unarj.o decode.o environ.o - $(CC) $(CFLAGS) -o unarj unarj.o decode.o environ.o +unarj: unarj.o decode.o environ.o sanitize.o + $(CC) $(CFLAGS) -o unarj unarj.o decode.o environ.o sanitize.o strip unarj clean: @@ -19,3 +19,4 @@ unarj.o: unarj.c unarj.h Makefile environ.o: environ.c unarj.h Makefile decode.o: decode.c unarj.h Makefile +sanitize.o: sanitize.c unarj.h Makefile --- sanitize.c +++ sanitize.c @@ -0,0 +1,81 @@ +/* + * Path sanitation code by Ludwig Nussel . Public Domain. + */ + +#include "unarj.h" + +#include +#include +#include + +#ifndef PATH_CHAR +#define PATH_CHAR '/' +#endif +#ifndef MIN +#define MIN(x,y) ((x)<(y)?(x):(y)) +#endif + +/* copy src into dest converting the path to a relative one inside the current + * directory. dest must hold at least len bytes */ +void copy_path_relative(char *dest, char *src, size_t len) +{ + char* o = dest; + char* p = src; + + *o = '\0'; + + while(*p && *p == PATH_CHAR) ++p; + for(; len && *p;) + { + src = p; + p = strchr(src, PATH_CHAR); + if(!p) p = src+strlen(src); + + /* . => skip */ + if(p-src == 1 && *src == '.' ) + { + if(*p) src = ++p; + } + /* .. => pop one */ + else if(p-src == 2 && *src == '.' && src[1] == '.') + { + if(o != dest) + { + char* tmp; + *o = '\0'; + tmp = strrchr(dest, PATH_CHAR); + if(!tmp) + { + len += o-dest; + o = dest; + if(*p) ++p; + } + else + { + len += o-tmp; + o = tmp; + if(*p) ++p; + } + } + else /* nothing to pop */ + if(*p) ++p; + } + else + { + size_t copy; + if(o != dest) + { + --len; + *o++ = PATH_CHAR; + } + copy = MIN(p-src,len); + memcpy(o, src, copy); + len -= copy; + src += copy; + o += copy; + if(*p) ++p; + } + while(*p && *p == PATH_CHAR) ++p; + } + o[len?0:-1] = '\0'; +} --- unarj.c +++ unarj.c @@ -235,6 +235,8 @@ /* Functions */ +void copy_path_relative(char *dest, char *src, size_t len); + static void make_crctable() { @@ -738,11 +740,11 @@ no_output = 0; if (command == 'E') - strncopy(name, &filename[entry_pos], sizeof(name)); + copy_path_relative(name, &filename[entry_pos], sizeof(name)); else { strcpy(name, DEFAULT_DIR); - strncopy(name+strlen(name), filename, sizeof(name)-strlen(name)); + copy_path_relative(name+strlen(name), filename, sizeof(name)-strlen(name)); } if (host_os != OS)