/arch/arm/lib/sha1.S

  1/*
  2 *  linux/arch/arm/lib/sha1.S
  3 *
  4 *  SHA transform optimized for ARM
  5 *
  6 *  Copyright:	(C) 2005 by Nicolas Pitre <nico@fluxnic.net>
  7 *  Created:	September 17, 2005
  8 *
  9 *  This program is free software; you can redistribute it and/or modify
 10 *  it under the terms of the GNU General Public License version 2 as
 11 *  published by the Free Software Foundation.
 12 *
 13 *  The reference implementation for this code is linux/lib/sha1.c
 14 */
 15
 16#include <linux/linkage.h>
 17
 18	.text
 19
 20
 21/*
 22 * void sha_transform(__u32 *digest, const char *in, __u32 *W)
 23 *
 24 * Note: the "in" ptr may be unaligned.
 25 */
 26
 27ENTRY(sha_transform)
 28
 29	stmfd	sp!, {r4 - r8, lr}
 30
 31	@ for (i = 0; i < 16; i++)
 32	@         W[i] = be32_to_cpu(in[i]);
 33
 34#ifdef __ARMEB__
 35	mov	r4, r0
 36	mov	r0, r2
 37	mov	r2, #64
 38	bl	memcpy
 39	mov	r2, r0
 40	mov	r0, r4
 41#else
 42	mov	r3, r2
 43	mov	lr, #16
 441:	ldrb	r4, [r1], #1
 45	ldrb	r5, [r1], #1
 46	ldrb	r6, [r1], #1
 47	ldrb	r7, [r1], #1
 48	subs	lr, lr, #1
 49	orr	r5, r5, r4, lsl #8
 50	orr	r6, r6, r5, lsl #8
 51	orr	r7, r7, r6, lsl #8
 52	str	r7, [r3], #4
 53	bne	1b
 54#endif
 55
 56	@ for (i = 0; i < 64; i++)
 57	@         W[i+16] = ror(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 31);
 58
 59	sub	r3, r2, #4
 60	mov	lr, #64
 612:	ldr	r4, [r3, #4]!
 62	subs	lr, lr, #1
 63	ldr	r5, [r3, #8]
 64	ldr	r6, [r3, #32]
 65	ldr	r7, [r3, #52]
 66	eor	r4, r4, r5
 67	eor	r4, r4, r6
 68	eor	r4, r4, r7
 69	mov	r4, r4, ror #31
 70	str	r4, [r3, #64]
 71	bne	2b
 72
 73	/*
 74	 * The SHA functions are:
 75	 *
 76	 * f1(B,C,D) = (D ^ (B & (C ^ D)))
 77	 * f2(B,C,D) = (B ^ C ^ D)
 78	 * f3(B,C,D) = ((B & C) | (D & (B | C)))
 79	 *
 80	 * Then the sub-blocks are processed as follows:
 81	 *
 82	 * A' = ror(A, 27) + f(B,C,D) + E + K + *W++
 83	 * B' = A
 84	 * C' = ror(B, 2)
 85	 * D' = C
 86	 * E' = D
 87	 *
 88	 * We therefore unroll each loop 5 times to avoid register shuffling.
 89	 * Also the ror for C (and also D and E which are successivelyderived
 90	 * from it) is applied in place to cut on an additional mov insn for
 91	 * each round.
 92	 */
 93
 94	.macro	sha_f1, A, B, C, D, E
 95	ldr	r3, [r2], #4
 96	eor	ip, \C, \D
 97	add	\E, r1, \E, ror #2
 98	and	ip, \B, ip, ror #2
 99	add	\E, \E, \A, ror #27
100	eor	ip, ip, \D, ror #2
101	add	\E, \E, r3
102	add	\E, \E, ip
103	.endm
104
105	.macro	sha_f2, A, B, C, D, E
106	ldr	r3, [r2], #4
107	add	\E, r1, \E, ror #2
108	eor	ip, \B, \C, ror #2
109	add	\E, \E, \A, ror #27
110	eor	ip, ip, \D, ror #2
111	add	\E, \E, r3
112	add	\E, \E, ip
113	.endm
114
115	.macro	sha_f3, A, B, C, D, E
116	ldr	r3, [r2], #4
117	add	\E, r1, \E, ror #2
118	orr	ip, \B, \C, ror #2
119	add	\E, \E, \A, ror #27
120	and	ip, ip, \D, ror #2
121	add	\E, \E, r3
122	and	r3, \B, \C, ror #2
123	orr	ip, ip, r3
124	add	\E, \E, ip
125	.endm
126
127	ldmia	r0, {r4 - r8}
128
129	mov	lr, #4
130	ldr	r1, .L_sha_K + 0
131
132	/* adjust initial values */
133	mov	r6, r6, ror #30
134	mov	r7, r7, ror #30
135	mov	r8, r8, ror #30
136
1373:	subs	lr, lr, #1
138	sha_f1	r4, r5, r6, r7, r8
139	sha_f1	r8, r4, r5, r6, r7
140	sha_f1	r7, r8, r4, r5, r6
141	sha_f1	r6, r7, r8, r4, r5
142	sha_f1	r5, r6, r7, r8, r4
143	bne	3b
144
145	ldr	r1, .L_sha_K + 4
146	mov	lr, #4
147
1484:	subs	lr, lr, #1
149	sha_f2	r4, r5, r6, r7, r8
150	sha_f2	r8, r4, r5, r6, r7
151	sha_f2	r7, r8, r4, r5, r6
152	sha_f2	r6, r7, r8, r4, r5
153	sha_f2	r5, r6, r7, r8, r4
154	bne	4b
155
156	ldr	r1, .L_sha_K + 8
157	mov	lr, #4
158
1595:	subs	lr, lr, #1
160	sha_f3	r4, r5, r6, r7, r8
161	sha_f3	r8, r4, r5, r6, r7
162	sha_f3	r7, r8, r4, r5, r6
163	sha_f3	r6, r7, r8, r4, r5
164	sha_f3	r5, r6, r7, r8, r4
165	bne	5b
166
167	ldr	r1, .L_sha_K + 12
168	mov	lr, #4
169
1706:	subs	lr, lr, #1
171	sha_f2	r4, r5, r6, r7, r8
172	sha_f2	r8, r4, r5, r6, r7
173	sha_f2	r7, r8, r4, r5, r6
174	sha_f2	r6, r7, r8, r4, r5
175	sha_f2	r5, r6, r7, r8, r4
176	bne	6b
177
178	ldmia	r0, {r1, r2, r3, ip, lr}
179	add	r4, r1, r4
180	add	r5, r2, r5
181	add	r6, r3, r6, ror #2
182	add	r7, ip, r7, ror #2
183	add	r8, lr, r8, ror #2
184	stmia	r0, {r4 - r8}
185
186	ldmfd	sp!, {r4 - r8, pc}
187
188ENDPROC(sha_transform)
189
190	.align	2
191.L_sha_K:
192	.word	0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6
193
194
195/*
196 * void sha_init(__u32 *buf)
197 */
198
199	.align	2
200.L_sha_initial_digest:
201	.word	0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0
202
203ENTRY(sha_init)
204
205	str	lr, [sp, #-4]!
206	adr	r1, .L_sha_initial_digest
207	ldmia	r1, {r1, r2, r3, ip, lr}
208	stmia	r0, {r1, r2, r3, ip, lr}
209	ldr	pc, [sp], #4
210
211ENDPROC(sha_init)