diff --git a/hash_intmd5.c b/hash_intmd5.c
index 64e0b9c..0b60f9b 100644
--- a/hash_intmd5.c
+++ b/hash_intmd5.c
@@ -49,18 +49,17 @@ HSH_Hash(int id, const unsigned char *in1, unsigned int in1_len,
     const unsigned char *in2, unsigned int in2_len,
     unsigned char *out, unsigned int out_len)
 {
-  if (out_len < 16)
-    return 0;
-
   MD5Init(&ctx);
   MD5Update(&ctx, in1, in1_len);
   if (in2)
     MD5Update(&ctx, in2, in2_len);
   MD5Final(&ctx);
 
-  memcpy(out, ctx.digest, 16);
+  out_len = MIN(out_len, 16);
 
-  return 16;
+  memcpy(out, ctx.digest, out_len);
+
+  return out_len;
 }
 
 void
diff --git a/hash_nss.c b/hash_nss.c
index eb1f050..9967bf8 100644
--- a/hash_nss.c
+++ b/hash_nss.c
@@ -32,6 +32,7 @@
 #include <nsslowhash.h>
 
 #include "hash.h"
+#include "util.h"
 
 static NSSLOWInitContext *ictx;
 
@@ -78,13 +79,17 @@ HSH_Hash(int id, const unsigned char *in1, unsigned int in1_len,
     const unsigned char *in2, unsigned int in2_len,
     unsigned char *out, unsigned int out_len)
 {
+  unsigned char buf[MAX_HASH_LENGTH];
   unsigned int ret = 0;
 
   NSSLOWHASH_Begin(hashes[id].context);
   NSSLOWHASH_Update(hashes[id].context, in1, in1_len);
   if (in2)
     NSSLOWHASH_Update(hashes[id].context, in2, in2_len);
-  NSSLOWHASH_End(hashes[id].context, out, &ret, out_len);
+  NSSLOWHASH_End(hashes[id].context, buf, &ret, sizeof (buf));
+
+  ret = MIN(ret, out_len);
+  memcpy(out, buf, ret);
 
   return ret;
 }
diff --git a/hash_tomcrypt.c b/hash_tomcrypt.c
index 5e16233..51b63d9 100644
--- a/hash_tomcrypt.c
+++ b/hash_tomcrypt.c
@@ -29,6 +29,7 @@
 
 #include "config.h"
 #include "hash.h"
+#include "util.h"
 
 struct hash {
   const char *name;
@@ -105,19 +106,24 @@ HSH_Hash(int id, const unsigned char *in1, unsigned int in1_len,
     const unsigned char *in2, unsigned int in2_len,
     unsigned char *out, unsigned int out_len)
 {
+  unsigned char buf[MAX_HASH_LENGTH];
   unsigned long len;
   int r;
 
-  len = out_len;
+  len = sizeof (buf);
   if (in2)
-    r = hash_memory_multi(id, out, &len,
-        in1, (unsigned long)in1_len, in2, (unsigned long)in2_len, NULL, 0);
+    r = hash_memory_multi(id, buf, &len,
+                          in1, (unsigned long)in1_len,
+                          in2, (unsigned long)in2_len, NULL, 0);
   else
-    r = hash_memory(id, in1, in1_len, out, &len);
+    r = hash_memory(id, in1, in1_len, buf, &len);
 
   if (r != CRYPT_OK)
     return 0;
 
+  len = MIN(len, out_len);
+  memcpy(out, buf, len);
+
   return len;
 }