diff --git a/OpenCL/m13711-pure.cl b/OpenCL/m13711-pure.cl
index e562ab14d..745adc55c 100644
--- a/OpenCL/m13711-pure.cl
+++ b/OpenCL/m13711-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -46,6 +47,7 @@ typedef struct vc
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc_tmp
 {
@@ -212,7 +214,7 @@ KERNEL_FQ void m13711_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[3] = ripemd160_hmac_ctx.opad.h[3];
   tmps[gid].opad[4] = ripemd160_hmac_ctx.opad.h[4];
 
-  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 16; i += 5, j += 1)
   {
diff --git a/OpenCL/m13712-pure.cl b/OpenCL/m13712-pure.cl
index 042e6a4fd..95ff2190a 100644
--- a/OpenCL/m13712-pure.cl
+++ b/OpenCL/m13712-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -261,7 +262,7 @@ KERNEL_FQ void m13712_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[3] = ripemd160_hmac_ctx.opad.h[3];
   tmps[gid].opad[4] = ripemd160_hmac_ctx.opad.h[4];
 
-  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 32; i += 5, j += 1)
   {
diff --git a/OpenCL/m13713-pure.cl b/OpenCL/m13713-pure.cl
index d7135e284..3f57e13ea 100644
--- a/OpenCL/m13713-pure.cl
+++ b/OpenCL/m13713-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -326,7 +327,7 @@ KERNEL_FQ void m13713_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[3] = ripemd160_hmac_ctx.opad.h[3];
   tmps[gid].opad[4] = ripemd160_hmac_ctx.opad.h[4];
 
-  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  ripemd160_hmac_update_global (&ripemd160_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 48; i += 5, j += 1)
   {
diff --git a/OpenCL/m13721-pure.cl b/OpenCL/m13721-pure.cl
index 209c1d62e..75b6bd7d6 100644
--- a/OpenCL/m13721-pure.cl
+++ b/OpenCL/m13721-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -238,7 +239,7 @@ KERNEL_FQ void m13721_init (KERN_ATTR_TMPS_ESALT (vc64_tmp_t, vc_t))
   tmps[gid].opad[6] = sha512_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha512_hmac_ctx.opad.h[7];
 
-  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 8; i += 8, j += 1)
   {
diff --git a/OpenCL/m13722-pure.cl b/OpenCL/m13722-pure.cl
index 52b18f9ee..d7f2b9806 100644
--- a/OpenCL/m13722-pure.cl
+++ b/OpenCL/m13722-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -289,7 +290,7 @@ KERNEL_FQ void m13722_init (KERN_ATTR_TMPS_ESALT (vc64_tmp_t, vc_t))
   tmps[gid].opad[6] = sha512_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha512_hmac_ctx.opad.h[7];
 
-  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 16; i += 8, j += 1)
   {
diff --git a/OpenCL/m13723-pure.cl b/OpenCL/m13723-pure.cl
index 3a49cc1b4..bbf2d8919 100644
--- a/OpenCL/m13723-pure.cl
+++ b/OpenCL/m13723-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -354,7 +355,7 @@ KERNEL_FQ void m13723_init (KERN_ATTR_TMPS_ESALT (vc64_tmp_t, vc_t))
   tmps[gid].opad[6] = sha512_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha512_hmac_ctx.opad.h[7];
 
-  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha512_hmac_update_global_swap (&sha512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 24; i += 8, j += 1)
   {
diff --git a/OpenCL/m13731-pure.cl b/OpenCL/m13731-pure.cl
index 06951a7d8..03161dd63 100644
--- a/OpenCL/m13731-pure.cl
+++ b/OpenCL/m13731-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -334,7 +335,7 @@ KERNEL_FQ void m13731_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[14] = whirlpool_hmac_ctx.opad.h[14];
   tmps[gid].opad[15] = whirlpool_hmac_ctx.opad.h[15];
 
-  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 16; i += 16, j += 1)
   {
diff --git a/OpenCL/m13732-pure.cl b/OpenCL/m13732-pure.cl
index 41263e8a4..9451e0df5 100644
--- a/OpenCL/m13732-pure.cl
+++ b/OpenCL/m13732-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -385,7 +386,7 @@ KERNEL_FQ void m13732_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[14] = whirlpool_hmac_ctx.opad.h[14];
   tmps[gid].opad[15] = whirlpool_hmac_ctx.opad.h[15];
 
-  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 32; i += 16, j += 1)
   {
diff --git a/OpenCL/m13733-pure.cl b/OpenCL/m13733-pure.cl
index 1d15ed3d2..1691f2791 100644
--- a/OpenCL/m13733-pure.cl
+++ b/OpenCL/m13733-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -450,7 +451,7 @@ KERNEL_FQ void m13733_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[14] = whirlpool_hmac_ctx.opad.h[14];
   tmps[gid].opad[15] = whirlpool_hmac_ctx.opad.h[15];
 
-  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  whirlpool_hmac_update_global_swap (&whirlpool_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 48; i += 16, j += 1)
   {
diff --git a/OpenCL/m13751-pure.cl b/OpenCL/m13751-pure.cl
index fbd04283c..bdf7fde4c 100644
--- a/OpenCL/m13751-pure.cl
+++ b/OpenCL/m13751-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -222,7 +223,7 @@ KERNEL_FQ void m13751_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[6] = sha256_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha256_hmac_ctx.opad.h[7];
 
-  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 16; i += 8, j += 1)
   {
diff --git a/OpenCL/m13752-pure.cl b/OpenCL/m13752-pure.cl
index ec02b0d8e..c903ed64b 100644
--- a/OpenCL/m13752-pure.cl
+++ b/OpenCL/m13752-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -273,7 +274,7 @@ KERNEL_FQ void m13752_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[6] = sha256_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha256_hmac_ctx.opad.h[7];
 
-  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 32; i += 8, j += 1)
   {
diff --git a/OpenCL/m13753-pure.cl b/OpenCL/m13753-pure.cl
index 4781af53f..baa0e9e2b 100644
--- a/OpenCL/m13753-pure.cl
+++ b/OpenCL/m13753-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -338,7 +339,7 @@ KERNEL_FQ void m13753_init (KERN_ATTR_TMPS_ESALT (vc_tmp_t, vc_t))
   tmps[gid].opad[6] = sha256_hmac_ctx.opad.h[6];
   tmps[gid].opad[7] = sha256_hmac_ctx.opad.h[7];
 
-  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  sha256_hmac_update_global_swap (&sha256_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 48; i += 8, j += 1)
   {
diff --git a/OpenCL/m13771-pure.cl b/OpenCL/m13771-pure.cl
index a9ab042b9..ee6f9adc9 100644
--- a/OpenCL/m13771-pure.cl
+++ b/OpenCL/m13771-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -306,7 +307,7 @@ KERNEL_FQ void m13771_init (KERN_ATTR_TMPS_ESALT (vc64_sbog_tmp_t, vc_t))
   tmps[gid].opad_raw[6] = streebog512_hmac_ctx.opad.s[6];
   tmps[gid].opad_raw[7] = streebog512_hmac_ctx.opad.s[7];
 
-  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   for (u32 i = 0, j = 1; i < 8; i += 8, j += 1)
   {
diff --git a/OpenCL/m13772-pure.cl b/OpenCL/m13772-pure.cl
index a44a0dab6..8c77189cc 100644
--- a/OpenCL/m13772-pure.cl
+++ b/OpenCL/m13772-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -357,7 +358,7 @@ KERNEL_FQ void m13772_init (KERN_ATTR_TMPS_ESALT (vc64_sbog_tmp_t, vc_t))
   tmps[gid].opad_raw[6] = streebog512_hmac_ctx.opad.s[6];
   tmps[gid].opad_raw[7] = streebog512_hmac_ctx.opad.s[7];
 
-  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   u32 i = 0;
   u32 j = 1;
diff --git a/OpenCL/m13773-pure.cl b/OpenCL/m13773-pure.cl
index 701c1b0f9..3aa411572 100644
--- a/OpenCL/m13773-pure.cl
+++ b/OpenCL/m13773-pure.cl
@@ -20,6 +20,7 @@
 #endif
 
 #define VC_DATA_LEN (448)
+#define VC_SALT_LEN ( 64)
 
 typedef struct vc
 {
@@ -422,7 +423,7 @@ KERNEL_FQ void m13773_init (KERN_ATTR_TMPS_ESALT (vc64_sbog_tmp_t, vc_t))
   tmps[gid].opad_raw[6] = streebog512_hmac_ctx.opad.s[6];
   tmps[gid].opad_raw[7] = streebog512_hmac_ctx.opad.s[7];
 
-  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, 64);
+  streebog512_hmac_update_global_swap (&streebog512_hmac_ctx, salt_bufs[SALT_POS_HOST].salt_buf, VC_SALT_LEN);
 
   u32 i = 0;
   u32 j = 1;
diff --git a/tools/veracrypt2hashcat.py b/tools/veracrypt2hashcat.py
index f29d01dfe..e08b2e175 100755
--- a/tools/veracrypt2hashcat.py
+++ b/tools/veracrypt2hashcat.py
@@ -1,5 +1,10 @@
 #!/usr/bin/env python3
 
+#
+# Author......: See docs/credits.txt
+# License.....: MIT
+#
+
 from argparse import ArgumentParser, ArgumentTypeError
 
 
@@ -23,9 +28,10 @@ def validate_offset(offset):
         offset = BOOTABLE_OFFSET + HIDDEN_OFFSET
     try:
         offset = int(offset)
-        assert offset >= 0
-    except (AssertionError, ValueError):
-        raise ArgumentTypeError("offset is nether non-negative number nor bootable, hidden or bootable+hidden value")
+    except ValueError as e:
+        raise ArgumentTypeError("value is nether number nor allowed string") from e
+    if offset < 0:
+        raise ArgumentTypeError("value cannot be less than zero")
     return offset
 
 
@@ -42,14 +48,18 @@ if __name__ == "__main__":
 
     args = parser.parse_args()
 
-    with open(args.path, "rb") as file:
-        file.seek(args.offset)
+    try:
+        with open(args.path, "rb") as file:
+            file.seek(args.offset)
 
-        header = file.read(HEADER_LENGTH)
+            header = file.read(HEADER_LENGTH)
 
-    assert len(header) == HEADER_LENGTH, "less data than needed"
+        if len(header) < HEADER_LENGTH:
+            parser.error("file contains less data than needed")
 
-    salt, data = header[:SALT_LENGTH], header[SALT_LENGTH:]
+        salt, data = header[:SALT_LENGTH], header[SALT_LENGTH:]
 
-    hash = SIGNATURE + salt.hex() + "$" + data.hex()
-    print(hash)
+        hash = SIGNATURE + salt.hex() + "$" + data.hex()
+        print(hash)
+    except IOError as e:
+        parser.error(e.strerror.lower())