diff options
Diffstat (limited to 'src/file_pdf.c')
| -rw-r--r-- | src/file_pdf.c | 208 |
1 files changed, 147 insertions, 61 deletions
diff --git a/src/file_pdf.c b/src/file_pdf.c index 16446978..1124546e 100644 --- a/src/file_pdf.c +++ b/src/file_pdf.c @@ -40,8 +40,10 @@ #include "memmem.h" #include "common.h" +/*@ + @ requires \valid(file_stat); + @*/ static void register_header_check_pdf(file_stat_t *file_stat); -static void file_date_pdf(file_recovery_t *file_recovery); const file_hint_t file_hint_pdf= { .extension="pdf", @@ -52,6 +54,9 @@ const file_hint_t file_hint_pdf= { .register_header_check=®ister_header_check_pdf }; +/*@ + @ assigns \nothing; + @*/ static int hex(int c) { if(c>='0' && c<='9') @@ -63,6 +68,11 @@ static int hex(int c) return -1; } +/*@ + @ requires \valid(file_recovery); + @ requires valid_read_string((char*)file_recovery->filename); + @ requires file_recovery->file_rename==&file_rename_pdf; + @*/ static void file_rename_pdf(file_recovery_t *file_recovery) { char title[512]; @@ -110,6 +120,9 @@ static void file_rename_pdf(file_recovery_t *file_recovery) fclose(handle); return ; } +#if defined(__FRAMAC__) + Frama_C_make_unknown(buffer, 512); +#endif fclose(handle); /* Skip spaces after /Title */ for(i=0; i<bsize && buffer[i]==' '; i++); @@ -185,47 +198,19 @@ static void file_rename_pdf(file_recovery_t *file_recovery) free(buffer); } -static void file_check_pdf_and_size(file_recovery_t *file_recovery) -{ - if(file_recovery->file_size>=file_recovery->calculated_file_size) - { - const unsigned int read_size=20; - unsigned char buffer[20+3]; /* read_size+3 */ - int i; - int taille; - file_recovery->file_size=file_recovery->calculated_file_size; - if(my_fseek(file_recovery->handle,file_recovery->file_size-read_size,SEEK_SET)<0) - { - file_recovery->file_size=0; - return ; - } - taille=fread(buffer,1,read_size,file_recovery->handle); - for(i=taille-4;i>=0;i--) - { - if(buffer[i]=='%' && buffer[i+1]=='E' && buffer[i+2]=='O' && buffer[i+3]=='F') - { - file_date_pdf(file_recovery); - return ; - } - } - } - file_recovery->file_size=0; -} - -static void file_check_pdf(file_recovery_t *file_recovery) -{ - const unsigned char pdf_footer[4]= { '%', 'E', 'O', 'F'}; - file_search_footer(file_recovery, pdf_footer, sizeof(pdf_footer), 0); - file_allow_nl(file_recovery, NL_BARENL|NL_CRLF|NL_BARECR); - file_date_pdf(file_recovery); -} - +/*@ + @ requires \valid(file_recovery); + @*/ static void file_date_pdf(file_recovery_t *file_recovery) { const unsigned char pattern[14]={'x', 'a', 'p', ':', 'C', 'r', 'e', 'a', 't', 'e', 'D', 'a', 't', 'e'}; uint64_t offset=0; unsigned int j=0; - unsigned char*buffer=(unsigned char*)MALLOC(4096); + unsigned char*buffer; + if(file_recovery->file_size > PHOTOREC_MAX_FILE_SIZE) + return ; + /*@ assert file_recovery->file_size <= PHOTOREC_MAX_FILE_SIZE; */ + buffer=(unsigned char*)MALLOC(4096); if(my_fseek(file_recovery->handle, 0, SEEK_SET)<0) { free(buffer); @@ -270,12 +255,130 @@ static void file_date_pdf(file_recovery_t *file_recovery) free(buffer); } -static int header_check_pdf(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new) + +#define PDF_READ_SIZE 20 + +/*@ + @ requires \valid(file_recovery); + @*/ +static void file_check_pdf_and_size(file_recovery_t *file_recovery) +{ + unsigned char buffer[PDF_READ_SIZE + 3]; + int i; + int taille; + if( file_recovery->file_size < file_recovery->calculated_file_size || + file_recovery->calculated_file_size < PDF_READ_SIZE) + { + file_recovery->file_size=0; + return; + } + /*@ assert file_recovery->calculated_file_size >= PDF_READ_SIZE; */ + file_recovery->file_size=file_recovery->calculated_file_size; + /*@ assert file_recovery->file_size >= PDF_READ_SIZE; */ + if(my_fseek(file_recovery->handle,file_recovery->file_size-PDF_READ_SIZE,SEEK_SET)<0) + { + file_recovery->file_size=0; + return ; + } + taille=fread(buffer, 1, PDF_READ_SIZE, file_recovery->handle); +#if defined(__FRAMAC__) + Frama_C_make_unknown((char *)&buffer, sizeof(buffer)); +#endif + for(i=taille-4;i>=0;i--) + { + if(buffer[i]=='%' && buffer[i+1]=='E' && buffer[i+2]=='O' && buffer[i+3]=='F') + { + file_date_pdf(file_recovery); + return ; + } + } + file_recovery->file_size=0; +} + +/*@ + @ requires \valid(file_recovery); + @*/ +static void file_check_pdf(file_recovery_t *file_recovery) +{ + const unsigned char pdf_footer[4]= { '%', 'E', 'O', 'F'}; + file_search_footer(file_recovery, pdf_footer, sizeof(pdf_footer), 0); + file_allow_nl(file_recovery, NL_BARENL|NL_CRLF|NL_BARECR); + file_date_pdf(file_recovery); +} + +/*@ + @ requires \valid_read(buffer+(0..512-1)); + @ assigns \nothing; + @*/ +static uint64_t read_pdf_file_aux(const unsigned char *buffer, unsigned int i) +{ + uint64_t file_size=0; + /*@ loop assigns i; */ + while(i < 512 && + (buffer[i] ==' ' || buffer[i]=='\t' || buffer[i]=='\n' || buffer[i]=='\r')) + i++; + /*@ + @ loop invariant file_size <= PHOTOREC_MAX_FILE_SIZE; + @ loop assigns i, file_size; + @ */ + for(;i<512 && buffer[i]>='0' && buffer[i]<='9'; i++) + { + file_size*=10; + file_size+=buffer[i]-'0'; + if(file_size > PHOTOREC_MAX_FILE_SIZE) + { + return PHOTOREC_MAX_FILE_SIZE + 1; + } + /*@ assert file_size <= PHOTOREC_MAX_FILE_SIZE; */ + } + return file_size; +} + +/*@ + @ requires \valid_read(buffer+(0..512-1)); + @*/ +static uint64_t read_pdf_file(const unsigned char *buffer) { const unsigned char sig_linearized[10]={'L','i','n','e','a','r','i','z','e','d'}; const unsigned char *src; + unsigned int i; + src=(const unsigned char *)td_memmem(buffer, 512, sig_linearized, sizeof(sig_linearized)); + if(src == NULL) + return 0; + i = src - buffer; + i+=sizeof(sig_linearized); + if( i >= 512 -1) + return 0; + /*@ assert i < 512-1; */ + /*@ + @ loop assigns i; + @ loop variant 512 - 1 - i; + @ */ + for(; i < 512-1 && buffer[i]!='>'; i++) + { + if(buffer[i]=='/' && buffer[i+1]=='L') + return read_pdf_file_aux(buffer, i+2); + } + return 0; +} + +/*@ + @ requires buffer_size >= 512; + @ requires \valid_read(buffer+(0..buffer_size-1)); + @ requires \valid_read(file_recovery); + @ requires file_recovery->file_stat==\null || valid_read_string((char*)file_recovery->filename); + @ requires \valid(file_recovery_new); + @ requires file_recovery_new->blocksize > 0; + @ requires separation: \separated(&file_hint_pdf, buffer, file_recovery, file_recovery_new); + @*/ +static int header_check_pdf(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new) +{ + uint64_t file_size; if(!isprint(buffer[6])) return 0; + file_size=read_pdf_file(buffer); + if(file_size > PHOTOREC_MAX_FILE_SIZE) + return 0; reset_file_recovery(file_recovery_new); if(td_memmem(buffer, buffer_size, "<</Illustrator ", 15) != NULL) file_recovery_new->extension="ai"; @@ -284,31 +387,14 @@ static int header_check_pdf(const unsigned char *buffer, const unsigned int buff file_recovery_new->extension=file_hint_pdf.extension; file_recovery_new->file_rename=&file_rename_pdf; } - if((src=(const unsigned char *)td_memmem(buffer, 512, sig_linearized, sizeof(sig_linearized))) != NULL) + if(file_size == 0) { - src+=sizeof(sig_linearized); - for(; src<=buffer+512 && *src!='>'; src++) - { - if(*src=='/' && *(src+1)=='L') - { - src+=2; - while(src<buffer+512 && - (*src==' ' || *src=='\t' || *src=='\n' || *src=='\r')) - src++; - file_recovery_new->calculated_file_size=0; - while(src<buffer+512 && - *src>='0' && *src<='9') - { - file_recovery_new->calculated_file_size=file_recovery_new->calculated_file_size*10+(*src)-'0'; - src++; - } - file_recovery_new->data_check=&data_check_size; - file_recovery_new->file_check=&file_check_pdf_and_size; - return 1; - } - } + file_recovery_new->file_check=&file_check_pdf; + return 1; } - file_recovery_new->file_check=&file_check_pdf; + file_recovery_new->calculated_file_size=file_size; + file_recovery_new->data_check=&data_check_size; + file_recovery_new->file_check=&file_check_pdf_and_size; return 1; } |