Take Debian's diff
Extract the 'Configure' patch

Go to the bit that says:
 ####
 #### Variety of LINUX:-)
 ####

Scroll up and find the "debian-arm" lines.
cd openssl-newver
cp Configure Configure.orig
Copy those debian-arm lines into the 'Configure' script above the "Variety of Linux" block.
diff -u Configure.orig Configure


If this causes any trouble during the patch, remove it:
my $x86_coff_asm="x86cpuid-cof.o:bn86-cof.o co86-cof.o:dx86-cof.o yx86-cof.o:ax86-cof.o:bx86-cof.o:mx86-cof.o:sx86-cof.o s512sse2-cof.o:cx86-cof.o:rx86-cof.o:rm86-cof.o:r58$
 my $x86_out_asm="x86cpuid-out.o:bn86-out.o co86-out.o:dx86-out.o yx86-out.o:ax86-out.o:bx86-out.o:mx86-out.o:sx86-out.o s512sse2-out.o:cx86-out.o:rx86-out.o:rm86-out.o:r586$

-my $x86_64_asm="x86_64cpuid.o:x86_64-gcc.o::::md5-x86_64.o:::rc4-x86_64.o::";
+#my $x86_64_asm="x86_64cpuid.o:x86_64-gcc.o::::md5-x86_64.o:::rc4-x86_64.o::";
+my $x86_64_asm="x86_64cpuid.o:x86_64-gcc.o::::md5-x86_64.o:::::";
 my $ia64_asm=":bn-ia64.o::aes_core.o aes_cbc.o aes-ia64.o:::sha1-ia64.o sha256-ia64.o sha512-ia64.o::rc4-ia64.o::";


Remove any modification to /usr/lib/engines (Debian uses /usr/lib/ssl/engines).
Only copy the main arch type section that contains
 debian-arm
 debian-mips
and so on.  The rest causes trouble and is not required.

Save the resulting patch file into 'arm/Configure.opts.diff'

REBUILD
-------

n/proftpd: seems to be picky about having an exact version of openssl.