diff options
Diffstat (limited to 'scd/app-openpgp.c')
| -rw-r--r-- | scd/app-openpgp.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/scd/app-openpgp.c b/scd/app-openpgp.c index 26ac91ea2..c2a8d5ffe 100644 --- a/scd/app-openpgp.c +++ b/scd/app-openpgp.c @@ -410,6 +410,10 @@ get_cached_data (app_t app, int tag, size_t len; struct cache_s *c; int exmode; + int do_constructed = 0; + + if ((tag < 0x0100 && (tag & 0x20)) || (tag >= 0x0100 && (tag & 0x2000))) + do_constructed = 1; *result = NULL; *resultlen = 0; @@ -452,6 +456,52 @@ get_cached_data (app_t app, int tag, err = iso7816_get_data (app_get_slot (app), exmode, tag, &p, &len); if (err) return err; + + /* When Data Object is constructed, when it comes with its tag and + length, remove them before storing it into the cache, because + it's redundant and takes space. This handling also works well + with the card implementation which doesn't include its tag and + length for the DO value returned by GET DATA. */ + if (do_constructed) + { + if (len && tag < 0x0100 && p[0] == tag) + { + if (len >= 2 && p[1] < 0x80 && p[1] == len - 2) + { + len -= 2; + memmove (p, p+2, len); + } + else if (len >= 3 && p[1] == 0x81 && p[2] == len - 3) + { + len -= 3; + memmove (p, p+3, len); + } + else if (len >= 4 && p[1] == 0x82 && ((p[2] << 8) | p[3]) == len - 4) + { + len -= 4; + memmove (p, p+4, len); + } + } + else if (len >= 2 && tag >= 0x0100 && ((p[0] << 8) | p[1]) == tag) + { + if (len >= 3 && p[2] < 0x80 && p[2] == len - 2) + { + len -= 3; + memmove (p, p+3, len); + } + else if (len >= 4 && p[2] == 0x81 && p[3] == len - 3) + { + len -= 4; + memmove (p, p+4, len); + } + else if (len >= 5 && p[2] == 0x82 && ((p[3] << 8) | p[4]) == len - 4) + { + len -= 5; + memmove (p, p+5, len); + } + } + } + if (len) *result = p; *resultlen = len; |