diff options
Diffstat (limited to 'archival/libunarchive/get_header_tar.c')
| -rw-r--r-- | archival/libunarchive/get_header_tar.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c index 622f09f..a965918 100644 --- a/archival/libunarchive/get_header_tar.c +++ b/archival/libunarchive/get_header_tar.c @@ -69,7 +69,7 @@ char get_header_tar(archive_handle_t *archive_handle) char padding[12]; /* 500-512 */ } tar; char *cp; - int sum, i; + int i, sum_u, sum_s, sum; int parse_names; if (sizeof(tar) != 512) @@ -110,16 +110,23 @@ char get_header_tar(archive_handle_t *archive_handle) #endif bb_error_msg_and_die("invalid tar magic"); } - /* Do checksum on headers */ - sum = ' ' * sizeof(tar.chksum); + + /* Do checksum on headers. + * POSIX says that checksum is done on unsigned bytes, but + * Sun and HP-UX fucked it up... more details in + * GNU tar source. */ + sum_s = sum_u = ' ' * sizeof(tar.chksum); for (i = 0; i < 148 ; i++) { - sum += ((char*)&tar)[i]; + sum_u += ((unsigned char*)&tar)[i]; + sum_s += ((signed char*)&tar)[i]; } for (i = 156; i < 512 ; i++) { - sum += ((char*)&tar)[i]; + sum_u += ((unsigned char*)&tar)[i]; + sum_s += ((signed char*)&tar)[i]; } /* This field does not need special treatment (getOctal) */ - if (sum != xstrtoul(tar.chksum, 8)) { + sum = xstrtoul(tar.chksum, 8); + if (sum_u != sum && sum_s != sum) { bb_error_msg_and_die("invalid tar header checksum"); } |