 GENERIC: pad-initial-bytes ( string sha2 -- padded-string )
 
 :: T1-256 ( n M H sha2 -- T1 )
-    n M nth
-    n sha2 K>> nth +
+    n M nth-unsafe
+    n sha2 K>> nth-unsafe +
     e H slice3 ch w+
-    e H nth S1-256 w+
-    h H nth w+ ; inline
+    e H nth-unsafe S1-256 w+
+    h H nth-unsafe w+ ; inline
 
 : T2-256 ( H -- T2 )
-    [ a swap nth S0-256 ]
+    [ a swap nth-unsafe S0-256 ]
     [ a swap slice3 maj w+ ] bi ; inline
 
 :: T1-512 ( n M H sha2 -- T1 )
-    n M nth
-    n sha2 K>> nth +
+    n M nth-unsafe
+    n sha2 K>> nth-unsafe +
     e H slice3 ch w+
-    e H nth S1-512 w+
-    h H nth w+ ; inline
+    e H nth-unsafe S1-512 w+
+    h H nth-unsafe w+ ; inline
 
 : T2-512 ( H -- T2 )
-    [ a swap nth S0-512 ]
+    [ a swap nth-unsafe S0-512 ]
     [ a swap slice3 maj w+ ] bi ; inline
 
 : update-H ( T1 T2 H -- )
-    h g pick exchange
-    g f pick exchange
-    f e pick exchange
-    pick d pick nth w+ e pick set-nth
-    d c pick exchange
-    c b pick exchange
-    b a pick exchange
-    [ w+ a ] dip set-nth ; inline
+    h g pick exchange-unsafe
+    g f pick exchange-unsafe
+    f e pick exchange-unsafe
+    pick d pick nth-unsafe w+ e pick set-nth-unsafe
+    d c pick exchange-unsafe
+    c b pick exchange-unsafe
+    b a pick exchange-unsafe
+    [ w+ a ] dip set-nth-unsafe ; inline
 
 : prepare-message-schedule ( seq sha2 -- w-seq )
     [ word-size>> <sliced-groups> [ be> ] map ]

! Copyright (C) 2008 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel splitting grouping math sequences namespaces make
io.binary math.bitwise checksums checksums.common
sbufs strings combinators.smart math.ranges fry combinators
accessors locals checksums.stream multiline literals
generalizations ;
IN: checksums.sha

SINGLETON: sha1

    [ [ block-size>> ] [ H>> clone ] [ ] tri process-chunk ] bi ;

: seq>byte-array ( seq n -- string )
    '[ _ >be ] map B{ } concat-as ;

: sha1>checksum ( sha2 -- bytes )
    H>> 4 seq>byte-array ;
