cannot build world

Cannot build today's CURRENT world.

===> sbin/geom (depend)
===> sbin/geom/core (depend)
rm -f .depend
mkdep -f .depend -a    -DCLASS_DIR=\"/lib/geom\" -I/usr/src/sbin/geom/core/../../../sys -I/
usr/src/sbin/geom/core -I/usr/src/sbi
n/geom/core/.. /usr/src/sbin/geom/core/geom.c /usr/src/sbin/geom/core/../misc/subr.c
echo geom: /usr/obj/usr/src/tmp/usr/lib/libc.a /usr/obj/usr/src/tmp/usr/lib/libgeom.a /usr/
obj/usr/src/tmp/usr/lib/libsbuf.a /us
r/obj/usr/src/tmp/usr/lib/libbsdxml.a /usr/obj/usr/src/tmp/usr/lib/libutil.a >> .depend
===> sbin/geom/class (depend)
===> sbin/geom/class/concat (depend)
rm -f .depend
mkdep -f .depend -a    -I/usr/src/sbin/geom/class/concat/../.. /usr/src/sbin/geom/class/con
cat/geom_concat.c /usr/src/sbin/geom/
class/concat/../../misc/subr.c
===> sbin/geom/class/eli (depend)
rm -f .depend
mkdep -f .depend -a    -I/usr/src/sbin/geom/class/eli/../../../../sys -I/usr/src/sbin/geom/
class/eli/../.. /usr/src/sbin/geom/cl
ass/eli/../../../../sys/geom/eli/g_eli_crypto.c /usr/src/sbin/geom/class/eli/../../../../sy
s/geom/eli/g_eli_key.c /usr/src/sbin/
geom/class/eli/../../../../sys/geom/eli/pkcs5v2.c /usr/src/sbin/geom/class/eli/../../../../
sys/crypto/sha2/sha2.c /usr/src/sbin/
geom/class/eli/geom_eli.c /usr/src/sbin/geom/class/eli/../../misc/subr.c
/usr/src/sbin/geom/class/eli/../../../../sys/geom/eli/g_eli_crypto.c:42:25: openssl/evp.h: 
No such file or directory
mkdep: compile failed
*** Error code 1

Stop in /usr/src/sbin/geom/class/eli.
*** Error code 1

Stop in /usr/src/sbin/geom/class.

Stop in /usr/src/sbin/geom.
*** Error code 1

*** Error code 1
Stop in /usr/src/sbin.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.