diff --git a/Makefile.org b/Makefile.org
index 629cdaeffd065a7eddb2078638efe3f91bc0b6a4..1c4fd984623c59b3d4fe6259ed6c541ad2bc7d0a 100644
--- a/Makefile.org
+++ b/Makefile.org
@@ -143,7 +143,7 @@ SDIRS=  \
 	bn ec rsa dsa ecdsa dh ecdh dso engine \
 	buffer bio stack lhash rand err \
 	evp asn1 pem x509 x509v3 conf txt_db pkcs7 pkcs12 comp ocsp ui \
-	cms pqueue ts jpake srp store cmac ct
+	cms pqueue ts jpake srp store cmac ct async
 # keep in mind that the above list is adjusted by ./Configure
 # according to no-xxx arguments...
 
diff --git a/crypto/async/Makefile b/crypto/async/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..2eaaa7d09e4cf354eeac550ca8de896f5c3603df
--- /dev/null
+++ b/crypto/async/Makefile
@@ -0,0 +1,83 @@
+#
+# OpenSSL/crypto/async/Makefile
+#
+
+DIR=	async
+TOP=	../..
+CC=	cc
+INCLUDES=
+CFLAG=-g
+MAKEFILE=	Makefile
+AR=		ar r
+
+CFLAGS= $(INCLUDES) $(CFLAG)
+
+GENERAL=Makefile
+TEST=
+APPS=
+
+LIB=$(TOP)/libcrypto.a
+LIBSRC=async.c
+LIBOBJ=async.o
+
+SRC= $(LIBSRC)
+
+EXHEADER= async.h
+HEADER=	$(EXHEADER)
+
+ALL=    $(GENERAL) $(SRC) $(HEADER)
+
+top:
+	(cd ../..; $(MAKE) DIRS=crypto SDIRS=$(DIR) sub_all)
+
+all:	lib
+
+lib:	$(LIBOBJ)
+	$(AR) $(LIB) $(LIBOBJ)
+	$(RANLIB) $(LIB) || echo Never mind.
+	@touch lib
+
+files:
+	$(PERL) $(TOP)/util/files.pl Makefile >> $(TOP)/MINFO
+
+links:
+	@$(PERL) $(TOP)/util/mklink.pl ../../include/openssl $(EXHEADER)
+	@$(PERL) $(TOP)/util/mklink.pl ../../test $(TEST)
+	@$(PERL) $(TOP)/util/mklink.pl ../../apps $(APPS)
+
+install:
+	@[ -n "$(INSTALLTOP)" ] # should be set by top Makefile...
+	@headerlist="$(EXHEADER)"; for i in $$headerlist ; \
+	do  \
+	(cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i; \
+	chmod 644 $(INSTALL_PREFIX)$(INSTALLTOP)/include/openssl/$$i ); \
+	done;
+
+tags:
+	ctags $(SRC)
+
+tests:
+
+lint:
+	lint -DLINT $(INCLUDES) $(SRC)>fluff
+
+update: depend
+
+depend:
+	@[ -n "$(MAKEDEPEND)" ] # should be set by upper Makefile...
+	$(MAKEDEPEND) -- $(CFLAG) $(INCLUDES) $(DEPFLAG) -- $(PROGS) $(LIBSRC)
+
+dclean:
+	$(PERL) -pe 'if (/^# DO NOT DELETE THIS LINE/) {print; exit(0);}' $(MAKEFILE) >Makefile.new
+	mv -f Makefile.new $(MAKEFILE)
+
+clean:
+	rm -f *.o *.obj lib tags core .pure .nfs* *.old *.bak fluff
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+async.o: ../../include/openssl/async.h ../../include/openssl/crypto.h
+async.o: ../../include/openssl/e_os2.h ../../include/openssl/opensslconf.h
+async.o: ../../include/openssl/opensslv.h ../../include/openssl/ossl_typ.h
+async.o: ../../include/openssl/safestack.h ../../include/openssl/stack.h
+async.o: ../../include/openssl/symhacks.h async.c
diff --git a/crypto/async/async.c b/crypto/async/async.c
new file mode 100644
index 0000000000000000000000000000000000000000..2f6eca1d43b21657d8852954edc88f5ee8c0b7b1
--- /dev/null
+++ b/crypto/async/async.c
@@ -0,0 +1,275 @@
+/* crypto/async/async.c */
+/*
+ * Written by Matt Caswell (matt@openssl.org) for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 2015 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+#include <openssl/crypto.h>
+#include <openssl/async.h>
+#include <ucontext.h>
+#include <string.h>
+
+#define ASYNC_JOB_RUNNING   0
+#define ASYNC_JOB_PAUSING   1
+#define ASYNC_JOB_PAUSED    2
+#define ASYNC_JOB_STOPPING  3
+
+
+typedef struct async_ctx_st {
+    ucontext_t dispatcher;
+    ASYNC_JOB *currjob;
+} ASYNC_CTX;
+
+__thread ASYNC_CTX *ctx;
+
+struct async_job_st {
+    ucontext_t fibrectx;
+    int (*func)(void *);
+    void *funcargs;
+    int ret;
+    int status;
+};
+
+
+static ASYNC_CTX *ASYNC_CTX_new(void)
+{
+    ASYNC_CTX *nctx = NULL;
+
+    if(!(nctx = OPENSSL_malloc(sizeof (ASYNC_CTX)))) {
+        /* Error here */
+        goto err;
+    }
+
+    nctx->currjob = NULL;
+    ctx = nctx;
+
+    return nctx;
+err:
+    if(nctx) {
+        OPENSSL_free(nctx);
+    }
+
+    return NULL;
+}
+
+static int ASYNC_CTX_free(void)
+{
+    if(ctx) {
+        OPENSSL_free(ctx);
+    }
+
+    ctx = NULL;
+
+    return 1;
+}
+
+static ASYNC_JOB *ASYNC_JOB_new(void)
+{
+    ASYNC_JOB *job = NULL;
+    void *stack = NULL;
+
+    if(!(job = OPENSSL_malloc(sizeof (ASYNC_JOB)))) {
+        goto err;
+    }
+
+    if(!(stack = OPENSSL_malloc(SIGSTKSZ))) {
+        goto err;
+    }
+    if(getcontext(&job->fibrectx))
+        goto err;
+    job->fibrectx.uc_stack.ss_sp = stack;
+    job->fibrectx.uc_stack.ss_size = SIGSTKSZ;
+    job->fibrectx.uc_link = NULL;
+    job->status = ASYNC_JOB_RUNNING;
+    job->funcargs = NULL;
+
+    return job;
+err:
+    if(job) {
+        if(stack)
+            OPENSSL_free(stack);
+        OPENSSL_free(job);
+    }
+    return NULL;
+}
+
+static void ASYNC_JOB_free(ASYNC_JOB *job)
+{
+    if(job) {
+        if(job->funcargs)
+            OPENSSL_free(job->funcargs);
+        if(job->fibrectx.uc_stack.ss_sp)
+            OPENSSL_free(job->fibrectx.uc_stack.ss_sp);
+        OPENSSL_free(job);
+    }
+}
+
+static void ASYNC_start_func(void)
+{
+    ASYNC_JOB *job;
+
+    /* Run the job */
+    job = ctx->currjob;
+    job->ret = job->func(job->funcargs);
+
+    /* Stop the job */
+    job->status = ASYNC_JOB_STOPPING;
+    setcontext(&ctx->dispatcher);
+
+    /*
+     * Should not happen. Getting here will close the thread...can't do much
+     * about it
+     */
+}
+
+int ASYNC_start_job(ASYNC_JOB **job, int *ret, int (*func)(void *),
+                         void *args, size_t size)
+{
+    if(ctx || !ASYNC_CTX_new()) {
+        return ASYNC_ERR;
+    }
+
+    if(*job) {
+        ctx->currjob = *job;
+    }
+
+    getcontext(&ctx->dispatcher);
+
+    if(ctx->currjob) {
+        if(ctx->currjob->status == ASYNC_JOB_STOPPING) {
+            *ret = ctx->currjob->ret;
+            ASYNC_JOB_free(ctx->currjob);
+            ctx->currjob = NULL;
+            ASYNC_CTX_free();
+            return ASYNC_FINISH;
+        }
+
+        if(ctx->currjob->status == ASYNC_JOB_PAUSING) {
+            *job = ctx->currjob;
+            ctx->currjob->status = ASYNC_JOB_PAUSED;
+            ASYNC_CTX_free();
+            return ASYNC_PAUSE;
+        }
+
+        if(ctx->currjob->status == ASYNC_JOB_PAUSED) {
+            ctx->currjob = *job;
+            /* Resume previous job */
+            setcontext(&ctx->currjob->fibrectx);
+            /* Does not return */
+        }
+
+        /* Should not happen */
+        ASYNC_JOB_free(ctx->currjob);
+        ctx->currjob = NULL;
+        ASYNC_CTX_free();
+        return ASYNC_ERR;
+    }
+
+    /* Start a new job */
+    if(!(ctx->currjob = ASYNC_JOB_new())) {
+        ASYNC_CTX_free();
+        return ASYNC_ERR;
+    }
+
+    if(args != NULL) {
+        ctx->currjob->funcargs = OPENSSL_malloc(size);
+        if(!ctx->currjob->funcargs) {
+            ASYNC_JOB_free(ctx->currjob);
+            ctx->currjob = NULL;
+            ASYNC_CTX_free();
+            return ASYNC_ERR;
+        }
+        memcpy(ctx->currjob->funcargs, args, size);
+    } else {
+        ctx->currjob->funcargs = NULL;
+    }
+
+    ctx->currjob->func = func;
+    makecontext(&ctx->currjob->fibrectx, ASYNC_start_func, 0);
+    setcontext(&ctx->currjob->fibrectx);
+
+    /* Does not return except in error */
+    ASYNC_JOB_free(ctx->currjob);
+    ctx->currjob = NULL;
+    ASYNC_CTX_free();
+    return ASYNC_ERR;
+}
+
+
+int ASYNC_pause_job(void)
+{
+    ASYNC_JOB *job;
+
+    if(!ctx || !ctx->currjob)
+        return 0;
+
+    job = ctx->currjob;
+    job->status = ASYNC_JOB_PAUSING;
+
+    if(swapcontext(&job->fibrectx, &ctx->dispatcher)) {
+        /* Error */
+        return 0;
+    }
+
+    return 1;
+}
+
+int ASYNC_in_job(void)
+{
+    if(ctx)
+        return 1;
+
+    return 0;
+}
+
+int ASYNC_job_is_waiting(ASYNC_JOB *job)
+{
+    return job->status == ASYNC_JOB_PAUSED;
+}
diff --git a/include/openssl/async.h b/include/openssl/async.h
new file mode 100644
index 0000000000000000000000000000000000000000..bf5a021942ffeb01bd5ce90c19d75563546f3e8b
--- /dev/null
+++ b/include/openssl/async.h
@@ -0,0 +1,77 @@
+/* include/openssl/async.h */
+/*
+ * Written by Matt Caswell (matt@openssl.org) for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 2015 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    licensing@OpenSSL.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+#ifndef HEADER_ASYNC_H
+# define HEADER_ASYNC_H
+
+# ifdef  __cplusplus
+extern "C" {
+# endif
+
+typedef struct async_job_st ASYNC_JOB;
+
+#define ASYNC_ERR      0
+#define ASYNC_PAUSE    1
+#define ASYNC_FINISH   2
+
+int ASYNC_start_job(ASYNC_JOB **job, int *ret, int (*func)(void *),
+                         void *args, size_t size);
+int ASYNC_pause_job(void);
+int ASYNC_in_job(void);
+int ASYNC_job_is_waiting(ASYNC_JOB *job);
+
+# ifdef  __cplusplus
+}
+# endif
+
+#endif