New file. About three times faster than

the optimized C code.

Rev: src/nettle/x86/arcfour-crypt.asm:1.1

diff --git a/x86/arcfour-crypt.asm b/x86/arcfour-crypt.asm
new file mode 100644 (file)
index 0000000..9f2f8eb
--- /dev/null
+++ b/x86/arcfour-crypt.asm
@@ -0,0 +1,75 @@
+C nettle, low-level cryptographics library
+C 
+C Copyright (C) 2004, Niels Möller
+C  
+C The nettle library is free software; you can redistribute it and/or modify
+C it under the terms of the GNU Lesser General Public License as published by
+C the Free Software Foundation; either version 2.1 of the License, or (at your
+C option) any later version.
+C 
+C The nettle library is distributed in the hope that it will be useful, but
+C WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+C or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+C License for more details.
+C 
+C You should have received a copy of the GNU Lesser General Public License
+C along with the nettle library; see the file COPYING.LIB.  If not, write to
+C the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+C MA 02111-1307, USA.
+
+       .file "arcfour.asm"
+
+       C arcfour_crypt(struct arcfour_ctx *ctx,
+       C               unsigned length, uint8_t *dst,
+       C               const uint8_t *src)
+       .text
+       .align 16
+       .globl nettle_arcfour_crypt
+       .type  nettle_arcfour_crypt,@function
+nettle_arcfour_crypt:
+       C save all registers that need to be saved
+       pushl   %ebx            C  16(%esp)
+       pushl   %ebp            C  12(%esp)
+       pushl   %esi            C  8(%esp)
+       pushl   %edi            C  4(%esp)
+
+       C ctx = 20(%esp)
+       C length = 24(%esp)
+       C dst = 28(%esp)
+       C src = 32(%esp)
+
+       movl    24(%esp), %edx          C  length
+       testl   %edx,%edx
+       jz      .Lend
+
+       movl    20(%esp), %ebp          C  ctx
+       movl    28(%esp), %edi
+       movl    32(%esp), %esi
+       addl    %esi, %edx              C  Keep src + length
+       
+       movzbl  256(%ebp), %eax         C  i
+       movzbl  257(%ebp), %ebx         C  j
+.Lloop:
+       incb    %al
+       movzbl  (%ebp, %eax), %ecx      C  si. Clears high bytes
+       addb    %cl, %bl
+       movb    (%ebp, %ebx), %ch       C  sj
+       movb    %ch, (%ebp, %eax)
+       addb    %ch, %cl
+       xorb    %ch, %ch                C  Clear, so it can be used
+                                       C  for indexing.
+       movb    (%ebp, %ecx), %cl
+       xorb    (%esi), %cl
+       incl    %esi
+       movb    %cl, (%edi)
+       incl    %edi
+       cmpl    %esi, %edx
+       jne     .Lloop
+.Lend:
+       popl    %edi
+       popl    %esi
+       popl    %ebp
+       popl    %ebx
+       ret
+.Leord:
+       .size   nettle_arcfour_crypt,.Leord-aes_decrypt