Enhance Dockerfile.optimized to include binutils for objcopy command and improve UPX compression strategy. Added steps to remove residual padding and compare compression results, ensuring the smallest binary size.

brute/source/Dockerfile.optimized

@@ -7,7 +7,8 @@ FROM alpine:latest AS build
 # musl-dev: C library headers for static linking
 # linux-headers: Kernel headers for system calls
 # upx: Ultimate Packer for eXecutables - binary compression tool
-RUN apk add --no-cache build-base musl-dev linux-headers upx
+# binutils: For objcopy command
+RUN apk add --no-cache build-base musl-dev linux-headers upx binutils
 
 # Set working directory for all subsequent operations
 WORKDIR /src
@@ -58,10 +59,17 @@ RUN gcc -static -Os -s \
         --remove-section=.note.* \
         --remove-section=.eh_frame \
         bruteforce \
-    # UPX compression with maximum settings:
-    # --lzma: Use LZMA compression algorithm (better ratio than default)
-    # --ultra-brute: Try all compression methods and use the best result
-    && upx --lzma --ultra-brute bruteforce
+    # === Remove residual padding BEFORE compression === \
+    && objcopy --pad-to=0 --gap-fill=0 bruteforce bruteforce.pad \
+    && mv bruteforce.pad bruteforce \
+    # === UPX variant shoot-out: keep smaller of two compressions === \
+    && cp bruteforce bruteforce.ultra && upx --ultra-brute bruteforce.ultra \
+    && cp bruteforce bruteforce.lzma  && upx --lzma --best --no-align bruteforce.lzma \
+    && if [ $(stat -c%s bruteforce.ultra) -le $(stat -c%s bruteforce.lzma) ]; then \
+         mv bruteforce.ultra bruteforce; rm bruteforce.lzma; \
+       else \
+         mv bruteforce.lzma bruteforce; rm bruteforce.ultra; \
+       fi
 
 # Final stage: Start with completely empty image (scratch)
 # This ensures absolute minimum size - no OS layer at all