[CRYPTO] salsa20_i586: Salsa20 stream cipher algorithm (i586 version)

This patch contains the salsa20-i586 implementation. The original
assembly code came from
<http://cr.yp.to/snuffle/salsa20/x86-pm/salsa20.s>. I have reformatted
it (added indents) so that it matches the other algorithms in
arch/x86/crypto.
Signed-off-by: Tan Swee Heng <thesweeheng@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/Makefile

@@ -4,12 +4,14 @@
 
 obj-$(CONFIG_CRYPTO_AES_586) += aes-i586.o
 obj-$(CONFIG_CRYPTO_TWOFISH_586) += twofish-i586.o
+obj-$(CONFIG_CRYPTO_SALSA20_586) += salsa20-i586.o
 
 obj-$(CONFIG_CRYPTO_AES_X86_64) += aes-x86_64.o
 obj-$(CONFIG_CRYPTO_TWOFISH_X86_64) += twofish-x86_64.o
 
 aes-i586-y := aes-i586-asm_32.o aes_glue.o
 twofish-i586-y := twofish-i586-asm_32.o twofish_32.o
+salsa20-i586-y := salsa20-i586-asm_32.o salsa20_glue.o
 
 aes-x86_64-y := aes-x86_64-asm_64.o aes_glue.o
 twofish-x86_64-y := twofish-x86_64-asm_64.o twofish_64.o

arch/x86/crypto/salsa20-i586-asm_32.S

+# salsa20_pm.s version 20051229
+# D. J. Bernstein
+# Public domain.
+
+# enter ECRYPT_encrypt_bytes
+.text
+.p2align 5
+.globl ECRYPT_encrypt_bytes
+ECRYPT_encrypt_bytes:
+	mov	%esp,%eax
+	and	$31,%eax
+	add	$256,%eax
+	sub	%eax,%esp
+	# eax_stack = eax
+	movl	%eax,80(%esp)
+	# ebx_stack = ebx
+	movl	%ebx,84(%esp)
+	# esi_stack = esi
+	movl	%esi,88(%esp)
+	# edi_stack = edi
+	movl	%edi,92(%esp)
+	# ebp_stack = ebp
+	movl	%ebp,96(%esp)
+	# x = arg1
+	movl	4(%esp,%eax),%edx
+	# m = arg2
+	movl	8(%esp,%eax),%esi
+	# out = arg3
+	movl	12(%esp,%eax),%edi
+	# bytes = arg4
+	movl	16(%esp,%eax),%ebx
+	# bytes -= 0
+	sub	$0,%ebx
+	# goto done if unsigned<=
+	jbe	._done
+._start:
+	# in0 = *(uint32 *) (x + 0)
+	movl	0(%edx),%eax
+	# in1 = *(uint32 *) (x + 4)
+	movl	4(%edx),%ecx
+	# in2 = *(uint32 *) (x + 8)
+	movl	8(%edx),%ebp
+	# j0 = in0
+	movl	%eax,164(%esp)
+	# in3 = *(uint32 *) (x + 12)
+	movl	12(%edx),%eax
+	# j1 = in1
+	movl	%ecx,168(%esp)
+	# in4 = *(uint32 *) (x + 16)
+	movl	16(%edx),%ecx
+	# j2 = in2
+	movl	%ebp,172(%esp)
+	# in5 = *(uint32 *) (x + 20)
+	movl	20(%edx),%ebp
+	# j3 = in3
+	movl	%eax,176(%esp)
+	# in6 = *(uint32 *) (x + 24)
+	movl	24(%edx),%eax
+	# j4 = in4
+	movl	%ecx,180(%esp)
+	# in7 = *(uint32 *) (x + 28)
+	movl	28(%edx),%ecx
+	# j5 = in5
+	movl	%ebp,184(%esp)
+	# in8 = *(uint32 *) (x + 32)
+	movl	32(%edx),%ebp
+	# j6 = in6
+	movl	%eax,188(%esp)
+	# in9 = *(uint32 *) (x + 36)
+	movl	36(%edx),%eax
+	# j7 = in7
+	movl	%ecx,192(%esp)
+	# in10 = *(uint32 *) (x + 40)
+	movl	40(%edx),%ecx
+	# j8 = in8
+	movl	%ebp,196(%esp)
+	# in11 = *(uint32 *) (x + 44)
+	movl	44(%edx),%ebp
+	# j9 = in9
+	movl	%eax,200(%esp)
+	# in12 = *(uint32 *) (x + 48)
+	movl	48(%edx),%eax
+	# j10 = in10
+	movl	%ecx,204(%esp)
+	# in13 = *(uint32 *) (x + 52)
+	movl	52(%edx),%ecx
+	# j11 = in11
+	movl	%ebp,208(%esp)
+	# in14 = *(uint32 *) (x + 56)
+	movl	56(%edx),%ebp
+	# j12 = in12
+	movl	%eax,212(%esp)
+	# in15 = *(uint32 *) (x + 60)
+	movl	60(%edx),%eax
+	# j13 = in13
+	movl	%ecx,216(%esp)
+	# j14 = in14
+	movl	%ebp,220(%esp)
+	# j15 = in15
+	movl	%eax,224(%esp)
+	# x_backup = x
+	movl	%edx,64(%esp)
+._bytesatleast1:
+	#   bytes - 64
+	cmp	$64,%ebx
+	#   goto nocopy if unsigned>=
+	jae	._nocopy
+	#     ctarget = out
+	movl	%edi,228(%esp)
+	#     out = &tmp
+	leal	0(%esp),%edi
+	#     i = bytes
+	mov	%ebx,%ecx
+	#     while (i) { *out++ = *m++; --i }
+	rep	movsb
+	#     out = &tmp
+	leal	0(%esp),%edi
+	#     m = &tmp
+	leal	0(%esp),%esi
+._nocopy:
+	#   out_backup = out
+	movl	%edi,72(%esp)
+	#   m_backup = m
+	movl	%esi,68(%esp)
+	#   bytes_backup = bytes
+	movl	%ebx,76(%esp)
+	#   in0 = j0
+	movl	164(%esp),%eax
+	#   in1 = j1
+	movl	168(%esp),%ecx
+	#   in2 = j2
+	movl	172(%esp),%edx
+	#   in3 = j3
+	movl	176(%esp),%ebx
+	#   x0 = in0
+	movl	%eax,100(%esp)
+	#   x1 = in1
+	movl	%ecx,104(%esp)
+	#   x2 = in2
+	movl	%edx,108(%esp)
+	#   x3 = in3
+	movl	%ebx,112(%esp)
+	#   in4 = j4
+	movl	180(%esp),%eax
+	#   in5 = j5
+	movl	184(%esp),%ecx
+	#   in6 = j6
+	movl	188(%esp),%edx
+	#   in7 = j7
+	movl	192(%esp),%ebx
+	#   x4 = in4
+	movl	%eax,116(%esp)
+	#   x5 = in5
+	movl	%ecx,120(%esp)
+	#   x6 = in6
+	movl	%edx,124(%esp)
+	#   x7 = in7
+	movl	%ebx,128(%esp)
+	#   in8 = j8
+	movl	196(%esp),%eax
+	#   in9 = j9
+	movl	200(%esp),%ecx
+	#   in10 = j10
+	movl	204(%esp),%edx
+	#   in11 = j11
+	movl	208(%esp),%ebx
+	#   x8 = in8
+	movl	%eax,132(%esp)
+	#   x9 = in9
+	movl	%ecx,136(%esp)
+	#   x10 = in10
+	movl	%edx,140(%esp)
+	#   x11 = in11
+	movl	%ebx,144(%esp)
+	#   in12 = j12
+	movl	212(%esp),%eax
+	#   in13 = j13
+	movl	216(%esp),%ecx
+	#   in14 = j14
+	movl	220(%esp),%edx
+	#   in15 = j15
+	movl	224(%esp),%ebx
+	#   x12 = in12
+	movl	%eax,148(%esp)
+	#   x13 = in13
+	movl	%ecx,152(%esp)
+	#   x14 = in14
+	movl	%edx,156(%esp)
+	#   x15 = in15
+	movl	%ebx,160(%esp)
+	#   i = 20
+	mov	$20,%ebp
+	# p = x0
+	movl	100(%esp),%eax
+	# s = x5
+	movl	120(%esp),%ecx
+	# t = x10
+	movl	140(%esp),%edx
+	# w = x15
+	movl	160(%esp),%ebx
+._mainloop:
+	# x0 = p
+	movl	%eax,100(%esp)
+	# 				x10 = t
+	movl	%edx,140(%esp)
+	# p += x12
+	addl	148(%esp),%eax
+	# 		x5 = s
+	movl	%ecx,120(%esp)
+	# 				t += x6
+	addl	124(%esp),%edx
+	# 						x15 = w
+	movl	%ebx,160(%esp)
+	# 		r = x1
+	movl	104(%esp),%esi
+	# 		r += s
+	add	%ecx,%esi
+	# 						v = x11
+	movl	144(%esp),%edi
+	# 						v += w
+	add	%ebx,%edi
+	# p <<<= 7
+	rol	$7,%eax
+	# p ^= x4
+	xorl	116(%esp),%eax
+	# 				t <<<= 7
+	rol	$7,%edx
+	# 				t ^= x14
+	xorl	156(%esp),%edx
+	# 		r <<<= 7
+	rol	$7,%esi
+	# 		r ^= x9
+	xorl	136(%esp),%esi
+	# 						v <<<= 7
+	rol	$7,%edi
+	# 						v ^= x3
+	xorl	112(%esp),%edi
+	# x4 = p
+	movl	%eax,116(%esp)
+	# 				x14 = t
+	movl	%edx,156(%esp)
+	# p += x0
+	addl	100(%esp),%eax
+	# 		x9 = r
+	movl	%esi,136(%esp)
+	# 				t += x10
+	addl	140(%esp),%edx
+	# 						x3 = v
+	movl	%edi,112(%esp)
+	# p <<<= 9
+	rol	$9,%eax
+	# p ^= x8
+	xorl	132(%esp),%eax
+	# 				t <<<= 9
+	rol	$9,%edx
+	# 				t ^= x2
+	xorl	108(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 9
+	rol	$9,%ecx
+	# 		s ^= x13
+	xorl	152(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 9
+	rol	$9,%ebx
+	# 						w ^= x7
+	xorl	128(%esp),%ebx
+	# x8 = p
+	movl	%eax,132(%esp)
+	# 				x2 = t
+	movl	%edx,108(%esp)
+	# p += x4
+	addl	116(%esp),%eax
+	# 		x13 = s
+	movl	%ecx,152(%esp)
+	# 				t += x14
+	addl	156(%esp),%edx
+	# 						x7 = w
+	movl	%ebx,128(%esp)
+	# p <<<= 13
+	rol	$13,%eax
+	# p ^= x12
+	xorl	148(%esp),%eax
+	# 				t <<<= 13
+	rol	$13,%edx
+	# 				t ^= x6
+	xorl	124(%esp),%edx
+	# 		r += s
+	add	%ecx,%esi
+	# 		r <<<= 13
+	rol	$13,%esi
+	# 		r ^= x1
+	xorl	104(%esp),%esi
+	# 						v += w
+	add	%ebx,%edi
+	# 						v <<<= 13
+	rol	$13,%edi
+	# 						v ^= x11
+	xorl	144(%esp),%edi
+	# x12 = p
+	movl	%eax,148(%esp)
+	# 				x6 = t
+	movl	%edx,124(%esp)
+	# p += x8
+	addl	132(%esp),%eax
+	# 		x1 = r
+	movl	%esi,104(%esp)
+	# 				t += x2
+	addl	108(%esp),%edx
+	# 						x11 = v
+	movl	%edi,144(%esp)
+	# p <<<= 18
+	rol	$18,%eax
+	# p ^= x0
+	xorl	100(%esp),%eax
+	# 				t <<<= 18
+	rol	$18,%edx
+	# 				t ^= x10
+	xorl	140(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 18
+	rol	$18,%ecx
+	# 		s ^= x5
+	xorl	120(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 18
+	rol	$18,%ebx
+	# 						w ^= x15
+	xorl	160(%esp),%ebx
+	# x0 = p
+	movl	%eax,100(%esp)
+	# 				x10 = t
+	movl	%edx,140(%esp)
+	# p += x3
+	addl	112(%esp),%eax
+	# p <<<= 7
+	rol	$7,%eax
+	# 		x5 = s
+	movl	%ecx,120(%esp)
+	# 				t += x9
+	addl	136(%esp),%edx
+	# 						x15 = w
+	movl	%ebx,160(%esp)
+	# 		r = x4
+	movl	116(%esp),%esi
+	# 		r += s
+	add	%ecx,%esi
+	# 						v = x14
+	movl	156(%esp),%edi
+	# 						v += w
+	add	%ebx,%edi
+	# p ^= x1
+	xorl	104(%esp),%eax
+	# 				t <<<= 7
+	rol	$7,%edx
+	# 				t ^= x11
+	xorl	144(%esp),%edx
+	# 		r <<<= 7
+	rol	$7,%esi
+	# 		r ^= x6
+	xorl	124(%esp),%esi
+	# 						v <<<= 7
+	rol	$7,%edi
+	# 						v ^= x12
+	xorl	148(%esp),%edi
+	# x1 = p
+	movl	%eax,104(%esp)
+	# 				x11 = t
+	movl	%edx,144(%esp)
+	# p += x0
+	addl	100(%esp),%eax
+	# 		x6 = r
+	movl	%esi,124(%esp)
+	# 				t += x10
+	addl	140(%esp),%edx
+	# 						x12 = v
+	movl	%edi,148(%esp)
+	# p <<<= 9
+	rol	$9,%eax
+	# p ^= x2
+	xorl	108(%esp),%eax
+	# 				t <<<= 9
+	rol	$9,%edx
+	# 				t ^= x8
+	xorl	132(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 9
+	rol	$9,%ecx
+	# 		s ^= x7
+	xorl	128(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 9
+	rol	$9,%ebx
+	# 						w ^= x13
+	xorl	152(%esp),%ebx
+	# x2 = p
+	movl	%eax,108(%esp)
+	# 				x8 = t
+	movl	%edx,132(%esp)
+	# p += x1
+	addl	104(%esp),%eax
+	# 		x7 = s
+	movl	%ecx,128(%esp)
+	# 				t += x11
+	addl	144(%esp),%edx
+	# 						x13 = w
+	movl	%ebx,152(%esp)
+	# p <<<= 13
+	rol	$13,%eax
+	# p ^= x3
+	xorl	112(%esp),%eax
+	# 				t <<<= 13
+	rol	$13,%edx
+	# 				t ^= x9
+	xorl	136(%esp),%edx
+	# 		r += s
+	add	%ecx,%esi
+	# 		r <<<= 13
+	rol	$13,%esi
+	# 		r ^= x4
+	xorl	116(%esp),%esi
+	# 						v += w
+	add	%ebx,%edi
+	# 						v <<<= 13
+	rol	$13,%edi
+	# 						v ^= x14
+	xorl	156(%esp),%edi
+	# x3 = p
+	movl	%eax,112(%esp)
+	# 				x9 = t
+	movl	%edx,136(%esp)
+	# p += x2
+	addl	108(%esp),%eax
+	# 		x4 = r
+	movl	%esi,116(%esp)
+	# 				t += x8
+	addl	132(%esp),%edx
+	# 						x14 = v
+	movl	%edi,156(%esp)
+	# p <<<= 18
+	rol	$18,%eax
+	# p ^= x0
+	xorl	100(%esp),%eax
+	# 				t <<<= 18
+	rol	$18,%edx
+	# 				t ^= x10
+	xorl	140(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 18
+	rol	$18,%ecx
+	# 		s ^= x5
+	xorl	120(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 18
+	rol	$18,%ebx
+	# 						w ^= x15
+	xorl	160(%esp),%ebx
+	# x0 = p
+	movl	%eax,100(%esp)
+	# 				x10 = t
+	movl	%edx,140(%esp)
+	# p += x12
+	addl	148(%esp),%eax
+	# 		x5 = s
+	movl	%ecx,120(%esp)
+	# 				t += x6
+	addl	124(%esp),%edx
+	# 						x15 = w
+	movl	%ebx,160(%esp)
+	# 		r = x1
+	movl	104(%esp),%esi
+	# 		r += s
+	add	%ecx,%esi
+	# 						v = x11
+	movl	144(%esp),%edi
+	# 						v += w
+	add	%ebx,%edi
+	# p <<<= 7
+	rol	$7,%eax
+	# p ^= x4
+	xorl	116(%esp),%eax
+	# 				t <<<= 7
+	rol	$7,%edx
+	# 				t ^= x14
+	xorl	156(%esp),%edx
+	# 		r <<<= 7
+	rol	$7,%esi
+	# 		r ^= x9
+	xorl	136(%esp),%esi
+	# 						v <<<= 7
+	rol	$7,%edi
+	# 						v ^= x3
+	xorl	112(%esp),%edi
+	# x4 = p
+	movl	%eax,116(%esp)
+	# 				x14 = t
+	movl	%edx,156(%esp)
+	# p += x0
+	addl	100(%esp),%eax
+	# 		x9 = r
+	movl	%esi,136(%esp)
+	# 				t += x10
+	addl	140(%esp),%edx
+	# 						x3 = v
+	movl	%edi,112(%esp)
+	# p <<<= 9
+	rol	$9,%eax
+	# p ^= x8
+	xorl	132(%esp),%eax
+	# 				t <<<= 9
+	rol	$9,%edx
+	# 				t ^= x2
+	xorl	108(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 9
+	rol	$9,%ecx
+	# 		s ^= x13
+	xorl	152(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 9
+	rol	$9,%ebx
+	# 						w ^= x7
+	xorl	128(%esp),%ebx
+	# x8 = p
+	movl	%eax,132(%esp)
+	# 				x2 = t
+	movl	%edx,108(%esp)
+	# p += x4
+	addl	116(%esp),%eax
+	# 		x13 = s
+	movl	%ecx,152(%esp)
+	# 				t += x14
+	addl	156(%esp),%edx
+	# 						x7 = w
+	movl	%ebx,128(%esp)
+	# p <<<= 13
+	rol	$13,%eax
+	# p ^= x12
+	xorl	148(%esp),%eax
+	# 				t <<<= 13
+	rol	$13,%edx
+	# 				t ^= x6
+	xorl	124(%esp),%edx
+	# 		r += s
+	add	%ecx,%esi
+	# 		r <<<= 13
+	rol	$13,%esi
+	# 		r ^= x1
+	xorl	104(%esp),%esi
+	# 						v += w
+	add	%ebx,%edi
+	# 						v <<<= 13
+	rol	$13,%edi
+	# 						v ^= x11
+	xorl	144(%esp),%edi
+	# x12 = p
+	movl	%eax,148(%esp)
+	# 				x6 = t
+	movl	%edx,124(%esp)
+	# p += x8
+	addl	132(%esp),%eax
+	# 		x1 = r
+	movl	%esi,104(%esp)
+	# 				t += x2
+	addl	108(%esp),%edx
+	# 						x11 = v
+	movl	%edi,144(%esp)
+	# p <<<= 18
+	rol	$18,%eax
+	# p ^= x0
+	xorl	100(%esp),%eax
+	# 				t <<<= 18
+	rol	$18,%edx
+	# 				t ^= x10
+	xorl	140(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 18
+	rol	$18,%ecx
+	# 		s ^= x5
+	xorl	120(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 18
+	rol	$18,%ebx
+	# 						w ^= x15
+	xorl	160(%esp),%ebx
+	# x0 = p
+	movl	%eax,100(%esp)
+	# 				x10 = t
+	movl	%edx,140(%esp)
+	# p += x3
+	addl	112(%esp),%eax
+	# p <<<= 7
+	rol	$7,%eax
+	# 		x5 = s
+	movl	%ecx,120(%esp)
+	# 				t += x9
+	addl	136(%esp),%edx
+	# 						x15 = w
+	movl	%ebx,160(%esp)
+	# 		r = x4
+	movl	116(%esp),%esi
+	# 		r += s
+	add	%ecx,%esi
+	# 						v = x14
+	movl	156(%esp),%edi
+	# 						v += w
+	add	%ebx,%edi
+	# p ^= x1
+	xorl	104(%esp),%eax
+	# 				t <<<= 7
+	rol	$7,%edx
+	# 				t ^= x11
+	xorl	144(%esp),%edx
+	# 		r <<<= 7
+	rol	$7,%esi
+	# 		r ^= x6
+	xorl	124(%esp),%esi
+	# 						v <<<= 7
+	rol	$7,%edi
+	# 						v ^= x12
+	xorl	148(%esp),%edi
+	# x1 = p
+	movl	%eax,104(%esp)
+	# 				x11 = t
+	movl	%edx,144(%esp)
+	# p += x0
+	addl	100(%esp),%eax
+	# 		x6 = r
+	movl	%esi,124(%esp)
+	# 				t += x10
+	addl	140(%esp),%edx
+	# 						x12 = v
+	movl	%edi,148(%esp)
+	# p <<<= 9
+	rol	$9,%eax
+	# p ^= x2
+	xorl	108(%esp),%eax
+	# 				t <<<= 9
+	rol	$9,%edx
+	# 				t ^= x8
+	xorl	132(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 9
+	rol	$9,%ecx
+	# 		s ^= x7
+	xorl	128(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 9
+	rol	$9,%ebx
+	# 						w ^= x13
+	xorl	152(%esp),%ebx
+	# x2 = p
+	movl	%eax,108(%esp)
+	# 				x8 = t
+	movl	%edx,132(%esp)
+	# p += x1
+	addl	104(%esp),%eax
+	# 		x7 = s
+	movl	%ecx,128(%esp)
+	# 				t += x11
+	addl	144(%esp),%edx
+	# 						x13 = w
+	movl	%ebx,152(%esp)
+	# p <<<= 13
+	rol	$13,%eax
+	# p ^= x3
+	xorl	112(%esp),%eax
+	# 				t <<<= 13
+	rol	$13,%edx
+	# 				t ^= x9
+	xorl	136(%esp),%edx
+	# 		r += s
+	add	%ecx,%esi
+	# 		r <<<= 13
+	rol	$13,%esi
+	# 		r ^= x4
+	xorl	116(%esp),%esi
+	# 						v += w
+	add	%ebx,%edi
+	# 						v <<<= 13
+	rol	$13,%edi
+	# 						v ^= x14
+	xorl	156(%esp),%edi
+	# x3 = p
+	movl	%eax,112(%esp)
+	# 				x9 = t
+	movl	%edx,136(%esp)
+	# p += x2
+	addl	108(%esp),%eax
+	# 		x4 = r
+	movl	%esi,116(%esp)
+	# 				t += x8
+	addl	132(%esp),%edx
+	# 						x14 = v
+	movl	%edi,156(%esp)
+	# p <<<= 18
+	rol	$18,%eax
+	# p ^= x0
+	xorl	100(%esp),%eax
+	# 				t <<<= 18
+	rol	$18,%edx
+	# 				t ^= x10
+	xorl	140(%esp),%edx
+	# 		s += r
+	add	%esi,%ecx
+	# 		s <<<= 18
+	rol	$18,%ecx
+	# 		s ^= x5
+	xorl	120(%esp),%ecx
+	# 						w += v
+	add	%edi,%ebx
+	# 						w <<<= 18
+	rol	$18,%ebx
+	# 						w ^= x15
+	xorl	160(%esp),%ebx
+	# i -= 4
+	sub	$4,%ebp
+	# goto mainloop if unsigned >
+	ja	._mainloop
+	# x0 = p
+	movl	%eax,100(%esp)
+	# x5 = s
+	movl	%ecx,120(%esp)
+	# x10 = t
+	movl	%edx,140(%esp)
+	# x15 = w
+	movl	%ebx,160(%esp)
+	#   out = out_backup
+	movl	72(%esp),%edi
+	#   m = m_backup
+	movl	68(%esp),%esi
+	#   in0 = x0
+	movl	100(%esp),%eax
+	#   in1 = x1
+	movl	104(%esp),%ecx
+	#   in0 += j0
+	addl	164(%esp),%eax
+	#   in1 += j1
+	addl	168(%esp),%ecx
+	#   in0 ^= *(uint32 *) (m + 0)
+	xorl	0(%esi),%eax
+	#   in1 ^= *(uint32 *) (m + 4)
+	xorl	4(%esi),%ecx
+	#   *(uint32 *) (out + 0) = in0
+	movl	%eax,0(%edi)
+	#   *(uint32 *) (out + 4) = in1
+	movl	%ecx,4(%edi)
+	#   in2 = x2
+	movl	108(%esp),%eax
+	#   in3 = x3
+	movl	112(%esp),%ecx
+	#   in2 += j2
+	addl	172(%esp),%eax
+	#   in3 += j3
+	addl	176(%esp),%ecx
+	#   in2 ^= *(uint32 *) (m + 8)
+	xorl	8(%esi),%eax
+	#   in3 ^= *(uint32 *) (m + 12)
+	xorl	12(%esi),%ecx
+	#   *(uint32 *) (out + 8) = in2
+	movl	%eax,8(%edi)
+	#   *(uint32 *) (out + 12) = in3
+	movl	%ecx,12(%edi)
+	#   in4 = x4
+	movl	116(%esp),%eax
+	#   in5 = x5
+	movl	120(%esp),%ecx
+	#   in4 += j4
+	addl	180(%esp),%eax
+	#   in5 += j5
+	addl	184(%esp),%ecx
+	#   in4 ^= *(uint32 *) (m + 16)
+	xorl	16(%esi),%eax
+	#   in5 ^= *(uint32 *) (m + 20)
+	xorl	20(%esi),%ecx
+	#   *(uint32 *) (out + 16) = in4
+	movl	%eax,16(%edi)
+	#   *(uint32 *) (out + 20) = in5
+	movl	%ecx,20(%edi)
+	#   in6 = x6
+	movl	124(%esp),%eax
+	#   in7 = x7
+	movl	128(%esp),%ecx
+	#   in6 += j6
+	addl	188(%esp),%eax
+	#   in7 += j7
+	addl	192(%esp),%ecx
+	#   in6 ^= *(uint32 *) (m + 24)
+	xorl	24(%esi),%eax
+	#   in7 ^= *(uint32 *) (m + 28)
+	xorl	28(%esi),%ecx
+	#   *(uint32 *) (out + 24) = in6
+	movl	%eax,24(%edi)
+	#   *(uint32 *) (out + 28) = in7
+	movl	%ecx,28(%edi)
+	#   in8 = x8
+	movl	132(%esp),%eax
+	#   in9 = x9
+	movl	136(%esp),%ecx
+	#   in8 += j8
+	addl	196(%esp),%eax
+	#   in9 += j9
+	addl	200(%esp),%ecx
+	#   in8 ^= *(uint32 *) (m + 32)
+	xorl	32(%esi),%eax
+	#   in9 ^= *(uint32 *) (m + 36)
+	xorl	36(%esi),%ecx
+	#   *(uint32 *) (out + 32) = in8
+	movl	%eax,32(%edi)
+	#   *(uint32 *) (out + 36) = in9
+	movl	%ecx,36(%edi)
+	#   in10 = x10
+	movl	140(%esp),%eax
+	#   in11 = x11
+	movl	144(%esp),%ecx
+	#   in10 += j10
+	addl	204(%esp),%eax
+	#   in11 += j11
+	addl	208(%esp),%ecx
+	#   in10 ^= *(uint32 *) (m + 40)
+	xorl	40(%esi),%eax
+	#   in11 ^= *(uint32 *) (m + 44)
+	xorl	44(%esi),%ecx
+	#   *(uint32 *) (out + 40) = in10
+	movl	%eax,40(%edi)
+	#   *(uint32 *) (out + 44) = in11
+	movl	%ecx,44(%edi)
+	#   in12 = x12
+	movl	148(%esp),%eax
+	#   in13 = x13
+	movl	152(%esp),%ecx
+	#   in12 += j12
+	addl	212(%esp),%eax
+	#   in13 += j13
+	addl	216(%esp),%ecx
+	#   in12 ^= *(uint32 *) (m + 48)
+	xorl	48(%esi),%eax
+	#   in13 ^= *(uint32 *) (m + 52)
+	xorl	52(%esi),%ecx
+	#   *(uint32 *) (out + 48) = in12
+	movl	%eax,48(%edi)
+	#   *(uint32 *) (out + 52) = in13
+	movl	%ecx,52(%edi)
+	#   in14 = x14
+	movl	156(%esp),%eax
+	#   in15 = x15
+	movl	160(%esp),%ecx
+	#   in14 += j14
+	addl	220(%esp),%eax
+	#   in15 += j15
+	addl	224(%esp),%ecx
+	#   in14 ^= *(uint32 *) (m + 56)
+	xorl	56(%esi),%eax
+	#   in15 ^= *(uint32 *) (m + 60)
+	xorl	60(%esi),%ecx
+	#   *(uint32 *) (out + 56) = in14
+	movl	%eax,56(%edi)
+	#   *(uint32 *) (out + 60) = in15
+	movl	%ecx,60(%edi)
+	#   bytes = bytes_backup
+	movl	76(%esp),%ebx
+	#   in8 = j8
+	movl	196(%esp),%eax
+	#   in9 = j9
+	movl	200(%esp),%ecx
+	#   in8 += 1
+	add	$1,%eax
+	#   in9 += 0 + carry
+	adc	$0,%ecx
+	#   j8 = in8
+	movl	%eax,196(%esp)
+	#   j9 = in9
+	movl	%ecx,200(%esp)
+	#   bytes - 64
+	cmp	$64,%ebx
+	#   goto bytesatleast65 if unsigned>
+	ja	._bytesatleast65
+	#     goto bytesatleast64 if unsigned>=
+	jae	._bytesatleast64
+	#       m = out
+	mov	%edi,%esi
+	#       out = ctarget
+	movl	228(%esp),%edi
+	#       i = bytes
+	mov	%ebx,%ecx
+	#       while (i) { *out++ = *m++; --i }
+	rep	movsb
+._bytesatleast64:
+	#     x = x_backup
+	movl	64(%esp),%eax
+	#     in8 = j8
+	movl	196(%esp),%ecx
+	#     in9 = j9
+	movl	200(%esp),%edx
+	#     *(uint32 *) (x + 32) = in8
+	movl	%ecx,32(%eax)
+	#     *(uint32 *) (x + 36) = in9
+	movl	%edx,36(%eax)
+._done:
+	#     eax = eax_stack
+	movl	80(%esp),%eax
+	#     ebx = ebx_stack
+	movl	84(%esp),%ebx
+	#     esi = esi_stack
+	movl	88(%esp),%esi
+	#     edi = edi_stack
+	movl	92(%esp),%edi
+	#     ebp = ebp_stack
+	movl	96(%esp),%ebp
+	#     leave
+	add	%eax,%esp
+	ret
+._bytesatleast65:
+	#   bytes -= 64
+	sub	$64,%ebx
+	#   out += 64
+	add	$64,%edi
+	#   m += 64
+	add	$64,%esi
+	# goto bytesatleast1
+	jmp	._bytesatleast1
+# enter ECRYPT_keysetup
+.text
+.p2align 5
+.globl ECRYPT_keysetup
+ECRYPT_keysetup:
+	mov	%esp,%eax
+	and	$31,%eax
+	add	$256,%eax
+	sub	%eax,%esp
+	#   eax_stack = eax
+	movl	%eax,64(%esp)
+	#   ebx_stack = ebx
+	movl	%ebx,68(%esp)
+	#   esi_stack = esi
+	movl	%esi,72(%esp)
+	#   edi_stack = edi
+	movl	%edi,76(%esp)
+	#   ebp_stack = ebp
+	movl	%ebp,80(%esp)
+	#   k = arg2
+	movl	8(%esp,%eax),%ecx
+	#   kbits = arg3
+	movl	12(%esp,%eax),%edx
+	#   x = arg1
+	movl	4(%esp,%eax),%eax
+	#   in1 = *(uint32 *) (k + 0)
+	movl	0(%ecx),%ebx
+	#   in2 = *(uint32 *) (k + 4)
+	movl	4(%ecx),%esi
+	#   in3 = *(uint32 *) (k + 8)
+	movl	8(%ecx),%edi
+	#   in4 = *(uint32 *) (k + 12)
+	movl	12(%ecx),%ebp
+	#   *(uint32 *) (x + 4) = in1
+	movl	%ebx,4(%eax)
+	#   *(uint32 *) (x + 8) = in2
+	movl	%esi,8(%eax)
+	#   *(uint32 *) (x + 12) = in3
+	movl	%edi,12(%eax)
+	#   *(uint32 *) (x + 16) = in4
+	movl	%ebp,16(%eax)
+	#   kbits - 256
+	cmp	$256,%edx
+	#   goto kbits128 if unsigned<
+	jb	._kbits128
+._kbits256:
+	#     in11 = *(uint32 *) (k + 16)
+	movl	16(%ecx),%edx
+	#     in12 = *(uint32 *) (k + 20)
+	movl	20(%ecx),%ebx
+	#     in13 = *(uint32 *) (k + 24)
+	movl	24(%ecx),%esi
+	#     in14 = *(uint32 *) (k + 28)
+	movl	28(%ecx),%ecx
+	#     *(uint32 *) (x + 44) = in11
+	movl	%edx,44(%eax)
+	#     *(uint32 *) (x + 48) = in12
+	movl	%ebx,48(%eax)
+	#     *(uint32 *) (x + 52) = in13
+	movl	%esi,52(%eax)
+	#     *(uint32 *) (x + 56) = in14
+	movl	%ecx,56(%eax)
+	#     in0 = 1634760805
+	mov	$1634760805,%ecx
+	#     in5 = 857760878
+	mov	$857760878,%edx
+	#     in10 = 2036477234
+	mov	$2036477234,%ebx
+	#     in15 = 1797285236
+	mov	$1797285236,%esi
+	#     *(uint32 *) (x + 0) = in0
+	movl	%ecx,0(%eax)
+	#     *(uint32 *) (x + 20) = in5
+	movl	%edx,20(%eax)
+	#     *(uint32 *) (x + 40) = in10
+	movl	%ebx,40(%eax)
+	#     *(uint32 *) (x + 60) = in15
+	movl	%esi,60(%eax)
+	#   goto keysetupdone
+	jmp	._keysetupdone
+._kbits128:
+	#     in11 = *(uint32 *) (k + 0)
+	movl	0(%ecx),%edx
+	#     in12 = *(uint32 *) (k + 4)
+	movl	4(%ecx),%ebx
+	#     in13 = *(uint32 *) (k + 8)
+	movl	8(%ecx),%esi
+	#     in14 = *(uint32 *) (k + 12)
+	movl	12(%ecx),%ecx
+	#     *(uint32 *) (x + 44) = in11
+	movl	%edx,44(%eax)
+	#     *(uint32 *) (x + 48) = in12
+	movl	%ebx,48(%eax)
+	#     *(uint32 *) (x + 52) = in13
+	movl	%esi,52(%eax)
+	#     *(uint32 *) (x + 56) = in14
+	movl	%ecx,56(%eax)
+	#     in0 = 1634760805
+	mov	$1634760805,%ecx
+	#     in5 = 824206446
+	mov	$824206446,%edx
+	#     in10 = 2036477238
+	mov	$2036477238,%ebx
+	#     in15 = 1797285236
+	mov	$1797285236,%esi
+	#     *(uint32 *) (x + 0) = in0
+	movl	%ecx,0(%eax)
+	#     *(uint32 *) (x + 20) = in5
+	movl	%edx,20(%eax)
+	#     *(uint32 *) (x + 40) = in10
+	movl	%ebx,40(%eax)
+	#     *(uint32 *) (x + 60) = in15
+	movl	%esi,60(%eax)
+._keysetupdone:
+	#   eax = eax_stack
+	movl	64(%esp),%eax
+	#   ebx = ebx_stack
+	movl	68(%esp),%ebx
+	#   esi = esi_stack
+	movl	72(%esp),%esi
+	#   edi = edi_stack
+	movl	76(%esp),%edi
+	#   ebp = ebp_stack
+	movl	80(%esp),%ebp
+	# leave
+	add	%eax,%esp
+	ret
+# enter ECRYPT_ivsetup
+.text
+.p2align 5
+.globl ECRYPT_ivsetup
+ECRYPT_ivsetup:
+	mov	%esp,%eax
+	and	$31,%eax
+	add	$256,%eax
+	sub	%eax,%esp
+	#   eax_stack = eax
+	movl	%eax,64(%esp)
+	#   ebx_stack = ebx
+	movl	%ebx,68(%esp)
+	#   esi_stack = esi
+	movl	%esi,72(%esp)
+	#   edi_stack = edi
+	movl	%edi,76(%esp)
+	#   ebp_stack = ebp
+	movl	%ebp,80(%esp)
+	#   iv = arg2
+	movl	8(%esp,%eax),%ecx
+	#   x = arg1
+	movl	4(%esp,%eax),%eax
+	#   in6 = *(uint32 *) (iv + 0)
+	movl	0(%ecx),%edx
+	#   in7 = *(uint32 *) (iv + 4)
+	movl	4(%ecx),%ecx
+	#   in8 = 0
+	mov	$0,%ebx
+	#   in9 = 0
+	mov	$0,%esi
+	#   *(uint32 *) (x + 24) = in6
+	movl	%edx,24(%eax)
+	#   *(uint32 *) (x + 28) = in7
+	movl	%ecx,28(%eax)
+	#   *(uint32 *) (x + 32) = in8
+	movl	%ebx,32(%eax)
+	#   *(uint32 *) (x + 36) = in9
+	movl	%esi,36(%eax)
+	#   eax = eax_stack
+	movl	64(%esp),%eax
+	#   ebx = ebx_stack
+	movl	68(%esp),%ebx
+	#   esi = esi_stack
+	movl	72(%esp),%esi
+	#   edi = edi_stack
+	movl	76(%esp),%edi
+	#   ebp = ebp_stack
+	movl	80(%esp),%ebp
+	# leave
+	add	%eax,%esp
+	ret

arch/x86/crypto/salsa20_glue.c

+/*
+ * Glue code for optimized assembly version of  Salsa20.
+ *
+ * Copyright (c) 2007 Tan Swee Heng <thesweeheng@gmail.com>
+ *
+ * The assembly codes are public domain assembly codes written by Daniel. J.
+ * Bernstein <djb@cr.yp.to>. The codes are modified to include indentation
+ * and to remove extraneous comments and functions that are not needed.
+ * - i586 version, renamed as salsa20-i586-asm_32.S
+ *   available from <http://cr.yp.to/snuffle/salsa20/x86-pm/salsa20.s>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <crypto/algapi.h>
+#include <linux/module.h>
+#include <linux/crypto.h>
+
+#define SALSA20_IV_SIZE        8U
+#define SALSA20_MIN_KEY_SIZE  16U
+#define SALSA20_MAX_KEY_SIZE  32U
+
+// use the ECRYPT_* function names
+#define salsa20_keysetup        ECRYPT_keysetup
+#define salsa20_ivsetup         ECRYPT_ivsetup
+#define salsa20_encrypt_bytes   ECRYPT_encrypt_bytes
+
+struct salsa20_ctx
+{
+	u32 input[16];
+};
+
+asmlinkage void salsa20_keysetup(struct salsa20_ctx *ctx, const u8 *k,
+				 u32 keysize, u32 ivsize);
+asmlinkage void salsa20_ivsetup(struct salsa20_ctx *ctx, const u8 *iv);
+asmlinkage void salsa20_encrypt_bytes(struct salsa20_ctx *ctx,
+				      const u8 *src, u8 *dst, u32 bytes);
+
+static int setkey(struct crypto_tfm *tfm, const u8 *key,
+		  unsigned int keysize)
+{
+	struct salsa20_ctx *ctx = crypto_tfm_ctx(tfm);
+	salsa20_keysetup(ctx, key, keysize*8, SALSA20_IV_SIZE*8);
+	return 0;
+}
+
+static int encrypt(struct blkcipher_desc *desc,
+		   struct scatterlist *dst, struct scatterlist *src,
+		   unsigned int nbytes)
+{
+	struct blkcipher_walk walk;
+	struct crypto_blkcipher *tfm = desc->tfm;
+	struct salsa20_ctx *ctx = crypto_blkcipher_ctx(tfm);
+	int err;
+
+	blkcipher_walk_init(&walk, dst, src, nbytes);
+	err = blkcipher_walk_virt_block(desc, &walk, 64);
+
+	salsa20_ivsetup(ctx, walk.iv);
+
+	if (likely(walk.nbytes == nbytes))
+	{
+		salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
+				      walk.dst.virt.addr, nbytes);
+		return blkcipher_walk_done(desc, &walk, 0);
+	}
+
+	while (walk.nbytes >= 64) {
+		salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
+				      walk.dst.virt.addr,
+				      walk.nbytes - (walk.nbytes % 64));
+		err = blkcipher_walk_done(desc, &walk, walk.nbytes % 64);
+	}
+
+	if (walk.nbytes) {
+		salsa20_encrypt_bytes(ctx, walk.src.virt.addr,
+				      walk.dst.virt.addr, walk.nbytes);
+		err = blkcipher_walk_done(desc, &walk, 0);
+	}
+
+	return err;
+}
+
+static struct crypto_alg alg = {
+	.cra_name           =   "salsa20",
+	.cra_driver_name    =   "salsa20-asm",
+	.cra_priority       =   200,
+	.cra_flags          =   CRYPTO_ALG_TYPE_BLKCIPHER,
+	.cra_type           =   &crypto_blkcipher_type,
+	.cra_blocksize      =   1,
+	.cra_ctxsize        =   sizeof(struct salsa20_ctx),
+	.cra_alignmask      =	3,
+	.cra_module         =   THIS_MODULE,
+	.cra_list           =   LIST_HEAD_INIT(alg.cra_list),
+	.cra_u              =   {
+		.blkcipher = {
+			.setkey         =   setkey,
+			.encrypt        =   encrypt,
+			.decrypt        =   encrypt,
+			.min_keysize    =   SALSA20_MIN_KEY_SIZE,
+			.max_keysize    =   SALSA20_MAX_KEY_SIZE,
+			.ivsize         =   SALSA20_IV_SIZE,
+		}
+	}
+};
+
+static int __init init(void)
+{
+	return crypto_register_alg(&alg);
+}
+
+static void __exit fini(void)
+{
+	crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm (optimized assembly version)");
+MODULE_ALIAS("salsa20");
+MODULE_ALIAS("salsa20-asm");

crypto/Kconfig

@@ -489,6 +489,21 @@ config CRYPTO_SALSA20
 	  The Salsa20 stream cipher algorithm is designed by Daniel J.
 	  Bernstein <djb@cr.yp.to>. See <http://cr.yp.to/snuffle.html>
 
+config CRYPTO_SALSA20_586
+	tristate "Salsa20 stream cipher algorithm (i586) (EXPERIMENTAL)"
+	depends on (X86 || UML_X86) && !64BIT
+	depends on EXPERIMENTAL
+	select CRYPTO_BLKCIPHER
+	select CRYPTO_SALSA20
+	help
+	  Salsa20 stream cipher algorithm.
+
+	  Salsa20 is a stream cipher submitted to eSTREAM, the ECRYPT
+	  Stream Cipher Project. See <http://www.ecrypt.eu.org/stream/>
+
+	  The Salsa20 stream cipher algorithm is designed by Daniel J.
+	  Bernstein <djb@cr.yp.to>. See <http://cr.yp.to/snuffle.html>
+
 config CRYPTO_DEFLATE
 	tristate "Deflate compression algorithm"
 	select CRYPTO_ALGAPI