II. Code Signing/custom/extract_cms.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Path to the binary
+binary_path="$1"
+cms_sign_out="$2"
+
+# Extract magic bytes offset
+binary_in_hex=$(xxd -p -u -c0 "$binary_path")
+offset=$(echo -n "$binary_in_hex" | grep -ob 'FADE0B01' | awk -F: 'NR==1{print $1}')
+
+# CMS data starts after the magic bytes and length, so you must add 8B to the offset value.
+CMS_offset_in_dec=$(( ($offset / 2) + 8))
+
+# Extract blob length
+CMS_length=$(echo -n "$binary_in_hex" | awk 'match($0, /FADE0B01/) { print substr($0, RSTART + RLENGTH, 8) }')
+
+# Extract the CMS Signature from the binary
+dd bs=1 skip="$CMS_offset_in_dec" count="0x$CMS_length" if="$binary_path" of="$cms_sign_out" 2>/dev/null