diff --git a/Makefile.in b/Makefile.in
index 6342acc..30be5fb 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -23,6 +23,7 @@ MAINOBJ= \
 	cpucount.c.o \
 	base32_to.c.o \
 	base32_from.c.o \
+	ioutil.c.o \
 	$(ED25519OBJ) \
 	keccak.c.o
 
diff --git a/ioutil.c b/ioutil.c
new file mode 100644
index 0000000..26c6254
--- /dev/null
+++ b/ioutil.c
@@ -0,0 +1,67 @@
+#include <stdint.h>
+#include <string.h>
+#include "types.h"
+#include "ioutil.h"
+#include <errno.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int writeall(FH fd,const u8 *data,size_t len)
+{
+	ssize_t wrote;
+	while (len) {
+		wrote = write(fd,data,len);
+		if (wrote == -1) {
+			if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+				continue;
+			return -1;
+		}
+		len -= wrote;
+		data += wrote;
+	}
+	return 0;
+}
+
+FH createfile(const char *path,int secret)
+{
+	int fd;
+	do {
+		fd = open(path,O_WRONLY | O_CREAT | O_TRUNC,secret ? 0600 : 0666);
+		if (fd == -1) {
+			if (errno == EINTR)
+				continue;
+			return -1;
+		}
+	} while (0);
+	return fd;
+}
+
+int closefile(FH fd)
+{
+	int cret;
+	do {
+		cret = close(fd);
+		if (cret == -1) {
+			if (errno == EINTR)
+				continue;
+			return -1;
+		}
+	} while (0);
+	return 0;
+}
+
+int writetofile(const char *path,const u8 *data,size_t len,int secret)
+{
+	FH fd = createfile(path,secret);
+	int wret = writeall(fd,data,len);
+	int cret = closefile(fd);
+	if (cret == -1)
+		return -1;
+	return wret;
+}
+
+int createdir(const char *path,int secret)
+{
+	return mkdir(path,secret ? 0700 : 0777);
+}
diff --git a/ioutil.h b/ioutil.h
new file mode 100644
index 0000000..7255a2e
--- /dev/null
+++ b/ioutil.h
@@ -0,0 +1,8 @@
+typedef int FH;
+#define FH_invalid -1
+
+FH createfile(const char *path,int secret);
+int closefile(FH fd);
+int writeall(FH,const u8 *data,size_t len);
+int writetofile(const char *path,const u8 *data,size_t len,int secret);
+int createdir(const char *path,int secret);
diff --git a/main.c b/main.c
index a0c69f8..6773af6 100644
--- a/main.c
+++ b/main.c
@@ -9,7 +9,6 @@
 #include <time.h>
 #include <pthread.h>
 #include <signal.h>
-#include <sys/stat.h>
 #include <sodium/randombytes.h>
 
 #include "types.h"
@@ -19,6 +18,7 @@
 #include "cpucount.h"
 #include "keccak.h"
 #include "ed25519/ed25519.h"
+#include "ioutil.h"
 
 // additional leading zero is added by C
 static const char * const pkprefix = "== ed25519v1-public: type0 ==\0\0";
@@ -646,8 +646,6 @@ VEC_STRUCT(tstatsvec,struct tstatstruct);
 
 static void onionready(char *sname, const u8 *secret, const u8 *pubonion)
 {
-	FILE *fh;
-
 	if (endwork)
 		return;
 
@@ -659,7 +657,7 @@ static void onionready(char *sname, const u8 *secret, const u8 *pubonion)
 		}
 	}
 
-	if (mkdir(sname,0700) != 0) {
+	if (createdir(sname,1) != 0) {
 		if (numneedgenerate)
 			pthread_mutex_unlock(&keysgenerated_mutex);
 		return;
@@ -673,26 +671,18 @@ static void onionready(char *sname, const u8 *secret, const u8 *pubonion)
 	}
 
 	strcpy(&sname[onionendpos], "/hs_ed25519_secret_key");
-	fh = fopen(sname, "wb");
-	if (fh) {
-		fwrite(secret, skprefixlen + SECRET_LEN, 1, fh);
-		fclose(fh);
-	}
+	writetofile(sname,secret,skprefixlen + SECRET_LEN,1);
 
 	strcpy(&sname[onionendpos], "/hostname");
-	fh = fopen(sname, "w");
-	if (fh) {
+	FILE *hfile = fopen(sname,"w");
+	if (hfile) {
 		sname[onionendpos] = '\n';
-		fwrite(&sname[direndpos], ONIONLEN+1, 1, fh);
-		fclose(fh);
+		fwrite(&sname[direndpos],ONIONLEN + 1,1,hfile);
+		fclose(hfile);
 	}
 
 	strcpy(&sname[onionendpos], "/hs_ed25519_public_key");
-	fh = fopen(sname, "wb");
-	if (fh) {
-		fwrite(pubonion, pkprefixlen + PUBLIC_LEN, 1, fh);
-		fclose(fh);
-	}
+	writetofile(sname,pubonion,pkprefixlen + PUBLIC_LEN,0);
 
 	if (fout) {
 		sname[onionendpos] = '\n';
@@ -1164,7 +1154,7 @@ int main(int argc,char **argv)
 		fout = fopen(outfile, "w");
 
 	if (workdir)
-		mkdir(workdir, 0700);
+		createdir(workdir,1);
 
 	direndpos = workdirlen;
 	onionendpos = workdirlen + ONIONLEN;