New file. About three times faster than

the optimized C code.

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

x86/arcfour-crypt.asm

+C nettle, low-level cryptographics library
+C 
+C Copyright (C) 2004, Niels Mller
+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