# Support routines for hand-crafting weird or malicious packs. # # You can make a complete pack like: # # pack_header 2 >foo.pack && # pack_obj e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 >>foo.pack && # pack_obj e68fe8129b546b101aee9510c5328e7f21ca1d18 >>foo.pack && # pack_trailer foo.pack # Print the big-endian 4-byte octal representation of $1 uint32_octal () { n=$1 printf '\\%o' $(($n / 16777216)); n=$((n % 16777216)) printf '\\%o' $(($n / 65536)); n=$((n % 65536)) printf '\\%o' $(($n / 256)); n=$((n % 256)) printf '\\%o' $(($n )); } # Print the big-endian 4-byte binary representation of $1 uint32_binary () { printf "$(uint32_octal "$1")" } # Print a pack header, version 2, for a pack with $1 objects pack_header () { printf 'PACK' && printf '\0\0\0\2' && uint32_binary "$1" } # Print the pack data for object $1, as a delta against object $2 (or as a full # object if $2 is missing or empty). The output is suitable for including # directly in the packfile, and represents the entirety of the object entry. # Doing this on the fly (especially picking your deltas) is quite tricky, so we # have hardcoded some well-known objects. See the case statements below for the # complete list. pack_obj () { test_oid_init case "$1" in # empty blob $EMPTY_BLOB) case "$2" in '') printf '\060\170\234\003\0\0\0\0\1' return ;; esac ;; # blob containing "\7\76" $(test_oid packlib_7_76)) case "$2" in '') printf '\062\170\234\143\267\3\0\0\116\0\106' return ;; 01d7713666f4de822776c7622c10f1b07de280dc) printf '\165\1\327\161\66\146\364\336\202\47\166' && printf '\307\142\54\20\361\260\175\342\200\334\170' && printf '\234\143\142\142\142\267\003\0\0\151\0\114' return ;; 37c8e2c15bb22b912e59b43fd51a4f7e9465ed0b5084c5a1411d991cbe630683) printf '\165\67\310\342\301\133\262\53\221\56\131' && printf '\264\77\325\32\117\176\224\145\355\13\120' && printf '\204\305\241\101\35\231\34\276\143\6\203\170' && printf '\234\143\142\142\142\267\003\0\0\151\0\114' return ;; esac ;; # blob containing "\7\0" $(test_oid packlib_7_0)) case "$2" in '') printf '\062\170\234\143\147\0\0\0\20\0\10' return ;; e68fe8129b546b101aee9510c5328e7f21ca1d18) printf '\165\346\217\350\22\233\124\153\20\32\356' && printf '\225\20\305\62\216\177\41\312\35\30\170\234' && printf '\143\142\142\142\147\0\0\0\53\0\16' return ;; 5d8e6fc40f2dab00e6983a48523fe57e621f46434cb58dbd4422fba03380d886) printf '\165\135\216\157\304\17\55\253\0\346\230\72' && printf '\110\122\77\345\176\142\37\106\103\114\265' && printf '\215\275\104\42\373\240\63\200\330\206\170\234' && printf '\143\142\142\142\147\0\0\0\53\0\16' return ;; esac ;; esac # If it's not a delta, we can convince pack-objects to generate a pack # with just our entry, and then strip off the header (12 bytes) and # trailer (20 bytes). if test -z "$2" then echo "$1" | git pack-objects --stdout >pack_obj.tmp && size=$(wc -c &2 "BUG: don't know how to print $1${2:+ (from $2)}" return 1 } # Compute and append pack trailer to "$1" pack_trailer () { test_oid_init && test-tool $(test_oid algo) -b <"$1" >trailer.tmp && cat trailer.tmp >>"$1" && rm -f trailer.tmp } # Remove any existing packs to make sure that # whatever we index next will be the pack that we # actually use. clear_packs () { rm -f .git/objects/pack/* } test_oid_cache <<-EOF packlib_7_0 sha1:01d7713666f4de822776c7622c10f1b07de280dc packlib_7_0 sha256:37c8e2c15bb22b912e59b43fd51a4f7e9465ed0b5084c5a1411d991cbe630683 packlib_7_76 sha1:e68fe8129b546b101aee9510c5328e7f21ca1d18 packlib_7_76 sha256:5d8e6fc40f2dab00e6983a48523fe57e621f46434cb58dbd4422fba03380d886 EOF