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@ -8,40 +8,45 @@ if ! which osslsigncode > /dev/null 2>&1; then |
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exit |
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fi |
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if [ $# -ne 2 ]; then |
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echo "Usage: $0 signed_binary unsigned_binary" |
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exit |
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fi |
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out="$1-stripped.exe" |
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set -ex |
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echo "Step 1: Remove PE signature from signed binary" |
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osslsigncode remove-signature -in $1 -out $out |
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echo "Step 2: Remove checksum from signed binary" |
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python3 <<EOF |
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# exit if command fails |
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set -e |
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mkdir -p stripped >/dev/null 2>&1 |
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cd signed |
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echo "Found $(ls *.exe | wc -w) files to verify." |
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for signed in $(ls *.exe); do |
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echo $signed |
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mine="../dist/$signed" |
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out="../stripped/$signed" |
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size=$( wc -c < $mine ) |
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# Step 1: Remove PE signature from signed binary |
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osslsigncode remove-signature -in $signed -out $out |
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# Step 2: Remove checksum and padding from signed binary |
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python3 <<EOF |
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pe_file = "$out" |
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size= $size |
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with open(pe_file, "rb") as f: |
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binary = bytearray(f.read()) |
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pe_offset = int.from_bytes(binary[0x3c:0x3c+4], byteorder="little") |
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checksum_offset = pe_offset + 88 |
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for b in range(4): |
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binary[checksum_offset + b] = 0 |
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l = len(binary) |
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n = l - size |
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if n > 0: |
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assert binary[-n:] == bytearray(n) |
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print("removing %d null bytes"% n) |
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binary = binary[:size] |
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with open(pe_file, "wb") as f: |
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f.write(binary) |
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EOF |
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bytes=$( wc -c < $2 ) |
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bytes=$((8 - ($bytes%8))) |
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bytes=$(($bytes % 8)) |
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echo "Step 3: Appending $bytes null bytes to unsigned binary" |
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truncate -s +$bytes $2 |
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diff $out $2 && echo "Success!" |
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chmod +x $out |
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if [ ! $(diff $out $mine) ]; then |
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echo "Success!" |
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gpg --sign --armor --detach $signed |
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else |
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echo "failure" |
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fi |
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done |
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