Commit a76ff953 authored by Jaromil's avatar Jaromil

All memory allocation is now static

Avoid calling malloc to compute the SHA256 hash of file.
Now getsha() reads chunks of 1MiB maximum until EOF.
parent fb6cbced
Pipeline #19 skipped
......@@ -82,20 +82,68 @@ static char *getpath(const char *str) {
return NULL;
#ifdef HASH
#define CHUNK 1048576 // 1MiB
static uint32 getsha(const char *path, unsigned char *dest) {
static sha256_context sha;
unsigned char buf[CHUNK]; // 1 MiB
uint32 len, tot;
FILE *fd;
fd = fopen(path,"r");
if(!fd) error("fopen", "cannot read binary file");
do {
// read chunk of data in binary file
len = fread(buf, 1, CHUNK, fd);
if(!len) break; // NULL read
if(len<CHUNK) break; // EOF reached
// compute sha256 of chunk
sha256_update(&sha, buf, len);
} while(len>0);
// check file descriptor for errors
if(ferror(fd)) {
error("fread", "error reading binary file");
// compute last chunk
if(len>0) sha256_update(&sha, buf, len);
// finish and save result in *dest
sha256_finish(&sha, dest);
int main(int argc, char **argv) {
static char fullcmd[MAXCMD];
static char *cmd;
struct passwd *pw;
struct stat st;
int i, uid, gid;
static int i, uid, gid;
static int target_uid=0;
static int target_gid=0;
#ifdef HASH
FILE *fd;
unsigned char *buf;
size_t len;
sha256_context sha;
unsigned char digest[32];
char output[65];
......@@ -105,9 +153,6 @@ int main(int argc, char **argv) {
char pidfile[MAXFILEPATH] = "";
int target_uid=0;
int target_gid=0;
// parse commandline options
int opt;
while((opt = getopt(argc, argv, "+hvdlu:g:p:")) != -1) {
......@@ -184,15 +229,18 @@ int main(int argc, char **argv) {
exit (0);
} // switch(opt)
} // getopt
// get the called UID and GID
uid = getuid ();
gid = getgid ();
// copy the execv argument locally
// save a pointer to basename string in cmd
cmd = basename(fullcmd);
// get the username string from /etc/passwd
......@@ -262,25 +310,14 @@ int main(int argc, char **argv) {
if( strlen(rules[i].hash) ) {
int c;
uint32 sizeread;
error("binsize", "cannot check hash of file, size too large");
fd = fopen(fullcmd,"r");
if(!fd) error("fopen", "cannot read binary file");
// TODO: split the read in chunks and remove alloc
buf = malloc(st.st_size);
if(!buf) error("malloc", "cannot allocate memory");
len = fread(buf,1,st.st_size,fd);
if(len != st.st_size) {
error("fread", "cannot read from binary file");
free(buf); fclose(fd); }
sha256_update(&sha, buf, (uint32)len);
sha256_finish(&sha, digest);
sizeread = getsha(fullcmd, digest);
if(sizeread != st.st_size)
error("getsha", "binary file size differs from size read");
for(c = 0; c<32; c++)
sprintf(output + (c * 2),"%02x",digest[c]);
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