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abuild-tar: embed checksum for symlinks

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and relocate the place of the symlink in tar header, as symlink
use the linkname field. now it's split to devmajor, devminor and
padding fields.
This commit is contained in:
Timo Teras 2009-08-11 19:56:11 +03:00
parent 6b2c6c0c03
commit 8b1a53011b
1 changed files with 31 additions and 13 deletions
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44
abuild-tar.c
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@ -42,6 +42,8 @@ struct tar_header {
char padding[12]; /* 500-512 */
};
#define MAX_MD_SIZE 20
#define GET_OCTAL(s) get_octal(s, sizeof(s))
#define PUT_OCTAL(s,v) put_octal(s, sizeof(s), v)
@ -94,10 +96,10 @@ static int usage(void)
fprintf(stderr,
"abuild-tar " VERSION "\n"
"\n"
"usage: abuild-tar [--hash [<algorithm>]] [--cut]\n"
"usage: abuild-tar [--hash[=<algorithm>]] [--cut]\n"
"\n"
"options:\n"
" --hash [sha1|md5] Read tar archive from stdin, precalculate hash for \n"
" --hash[=sha1|md5] Read tar archive from stdin, precalculate hash for \n"
" regular entries and output tar archive on stdout\n"
" --cut Remove the end of file tar record\n"
"\n");
@ -173,7 +175,7 @@ static int do_it(const EVP_MD *md, int cut)
struct tar_header hdr;
size_t size, aligned_size;
void *ptr;
int dohash = 0, r;
int r;
struct {
char id[4];
uint16_t nid;
@ -193,22 +195,34 @@ static int do_it(const EVP_MD *md, int cut)
if (cut && hdr.name[0] == 0)
return 0;
ptr = NULL;
size = GET_OCTAL(hdr.size);
aligned_size = (size + 511) & ~511;
if (md != NULL)
dohash = (hdr.typeflag == '0' || hdr.typeflag == '7');
if (dohash) {
if (md != NULL &&
(hdr.typeflag == '0' || hdr.typeflag == '2' ||
hdr.typeflag == '7')) {
const unsigned char *src;
unsigned char csdata[MAX_MD_SIZE];
int chksum, i;
ptr = malloc(aligned_size);
if (full_read(STDIN_FILENO, ptr, aligned_size) != aligned_size)
return 1;
if (hdr.typeflag == '0' || hdr.typeflag == '7') {
ptr = malloc(aligned_size);
if (full_read(STDIN_FILENO, ptr, aligned_size)
!= aligned_size)
return 1;
memcpy(&hdr.linkname[3], &mdinfo, sizeof(mdinfo));
EVP_Digest(ptr, size, &hdr.linkname[3+sizeof(mdinfo)],
NULL, md, NULL);
memcpy(&hdr.linkname[3], &mdinfo, sizeof(mdinfo));
EVP_Digest(ptr, size, csdata, NULL, md, NULL);
} else {
EVP_Digest(hdr.linkname, strlen(hdr.linkname),
csdata, NULL, md, NULL);
}
/* Embed to header */
memcpy(&hdr.devmajor, &mdinfo, sizeof(hdr.devmajor));
memcpy(&hdr.devminor, &csdata[0], sizeof(hdr.devminor));
memcpy(&hdr.padding, &csdata[sizeof(hdr.devminor)], sizeof(hdr.padding));
/* Recalculate checksum */
memset(hdr.chksum, ' ', sizeof(hdr.chksum));
@ -221,7 +235,7 @@ static int do_it(const EVP_MD *md, int cut)
if (full_write(STDOUT_FILENO, &hdr, sizeof(hdr)) != sizeof(hdr))
return 2;
if (dohash) {
if (ptr != NULL) {
if (full_write(STDOUT_FILENO, ptr, aligned_size) != aligned_size)
return 2;
free(ptr);
@ -271,6 +285,10 @@ int main(int argc, char **argv)
md = EVP_get_digestbyname(digest);
if (md == NULL)
return usage();
if (EVP_MD_size(md) > MAX_MD_SIZE) {
fprintf(stderr, "digest size is too large\n");
return -1;
}
}
return do_it(md, cut);