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140 lines
4.0 KiB
140 lines
4.0 KiB
# Support routines for hand-crafting weird or malicious packs. |
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# |
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# You can make a complete pack like: |
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# |
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# pack_header 2 >foo.pack && |
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# pack_obj e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 >>foo.pack && |
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# pack_obj e68fe8129b546b101aee9510c5328e7f21ca1d18 >>foo.pack && |
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# pack_trailer foo.pack |
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|
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# Print the big-endian 4-byte octal representation of $1 |
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uint32_octal () { |
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n=$1 |
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printf '\\%o' $(($n / 16777216)); n=$((n % 16777216)) |
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printf '\\%o' $(($n / 65536)); n=$((n % 65536)) |
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printf '\\%o' $(($n / 256)); n=$((n % 256)) |
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printf '\\%o' $(($n )); |
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} |
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# Print the big-endian 4-byte binary representation of $1 |
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uint32_binary () { |
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printf "$(uint32_octal "$1")" |
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} |
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|
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# Print a pack header, version 2, for a pack with $1 objects |
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pack_header () { |
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printf 'PACK' && |
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printf '\0\0\0\2' && |
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uint32_binary "$1" |
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} |
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# Print the pack data for object $1, as a delta against object $2 (or as a full |
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# object if $2 is missing or empty). The output is suitable for including |
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# directly in the packfile, and represents the entirety of the object entry. |
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# Doing this on the fly (especially picking your deltas) is quite tricky, so we |
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# have hardcoded some well-known objects. See the case statements below for the |
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# complete list. |
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pack_obj () { |
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case "$1" in |
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# empty blob |
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$EMPTY_BLOB) |
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case "$2" in |
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'') |
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printf '\060\170\234\003\0\0\0\0\1' |
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return |
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;; |
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esac |
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;; |
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# blob containing "\7\76" |
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$(test_oid packlib_7_76)) |
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case "$2" in |
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'') |
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printf '\062\170\234\143\267\3\0\0\116\0\106' |
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return |
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;; |
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01d7713666f4de822776c7622c10f1b07de280dc) |
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printf '\165\1\327\161\66\146\364\336\202\47\166' && |
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printf '\307\142\54\20\361\260\175\342\200\334\170' && |
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printf '\234\143\142\142\142\267\003\0\0\151\0\114' |
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return |
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;; |
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37c8e2c15bb22b912e59b43fd51a4f7e9465ed0b5084c5a1411d991cbe630683) |
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printf '\165\67\310\342\301\133\262\53\221\56\131' && |
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printf '\264\77\325\32\117\176\224\145\355\13\120' && |
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printf '\204\305\241\101\35\231\34\276\143\6\203\170' && |
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printf '\234\143\142\142\142\267\003\0\0\151\0\114' |
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return |
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;; |
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esac |
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;; |
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# blob containing "\7\0" |
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$(test_oid packlib_7_0)) |
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case "$2" in |
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'') |
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printf '\062\170\234\143\147\0\0\0\20\0\10' |
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return |
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;; |
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e68fe8129b546b101aee9510c5328e7f21ca1d18) |
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printf '\165\346\217\350\22\233\124\153\20\32\356' && |
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printf '\225\20\305\62\216\177\41\312\35\30\170\234' && |
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printf '\143\142\142\142\147\0\0\0\53\0\16' |
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return |
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;; |
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5d8e6fc40f2dab00e6983a48523fe57e621f46434cb58dbd4422fba03380d886) |
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printf '\165\135\216\157\304\17\55\253\0\346\230\72' && |
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printf '\110\122\77\345\176\142\37\106\103\114\265' && |
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printf '\215\275\104\42\373\240\63\200\330\206\170\234' && |
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printf '\143\142\142\142\147\0\0\0\53\0\16' |
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return |
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;; |
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esac |
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;; |
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# blob containing "\3\326" |
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471819e8c52bf11513f100b2810a8aa0622d5cd3d1c913758a071dd4b3bad8fe) |
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case "$2" in |
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'') |
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printf '\062\170\234\143\276\006\000\000\336\000\332' |
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return |
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;; |
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esac |
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esac |
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# If it's not a delta, we can convince pack-objects to generate a pack |
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# with just our entry, and then strip off the header (12 bytes) and |
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# trailer (20 bytes). |
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if test -z "$2" |
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then |
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echo "$1" | git pack-objects --stdout >pack_obj.tmp && |
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size=$(wc -c <pack_obj.tmp) && |
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dd if=pack_obj.tmp bs=1 count=$((size - $(test_oid rawsz) - 12)) skip=12 && |
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rm -f pack_obj.tmp |
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return |
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fi |
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echo >&2 "BUG: don't know how to print $1${2:+ (from $2)}" |
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return 1 |
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} |
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# Compute and append pack trailer to "$1" |
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pack_trailer () { |
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test-tool $(test_oid algo) -b <"$1" >trailer.tmp && |
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cat trailer.tmp >>"$1" && |
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rm -f trailer.tmp |
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} |
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# Remove any existing packs to make sure that |
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# whatever we index next will be the pack that we |
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# actually use. |
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clear_packs () { |
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rm -f .git/objects/pack/* |
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} |
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test_oid_cache <<-EOF |
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packlib_7_0 sha1:01d7713666f4de822776c7622c10f1b07de280dc |
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packlib_7_0 sha256:37c8e2c15bb22b912e59b43fd51a4f7e9465ed0b5084c5a1411d991cbe630683 |
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packlib_7_76 sha1:e68fe8129b546b101aee9510c5328e7f21ca1d18 |
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packlib_7_76 sha256:5d8e6fc40f2dab00e6983a48523fe57e621f46434cb58dbd4422fba03380d886 |
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EOF
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