--- /dev/null
+/*
+ * SHA transform optimized for ARM
+ *
+ * Copyright: (C) 2005 by Nicolas Pitre <nico@cam.org>
+ * Created: September 17, 2005
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+ .text
+ .globl sha_transform
+
+/*
+ * void sha_transform(uint32_t *hash, const unsigned char *data, uint32_t *W);
+ *
+ * note: the "data" pointer may be unaligned.
+ */
+
+sha_transform:
+
+ stmfd sp!, {r4 - r8, lr}
+
+ @ for (i = 0; i < 16; i++)
+ @ W[i] = ntohl(((uint32_t *)data)[i]); */
+
+#ifdef __ARMEB__
+ mov r4, r0
+ mov r0, r2
+ mov r2, #64
+ bl memcpy
+ mov r2, r0
+ mov r0, r4
+#else
+ mov r3, r2
+ mov lr, #16
+1: ldrb r4, [r1], #1
+ ldrb r5, [r1], #1
+ ldrb r6, [r1], #1
+ ldrb r7, [r1], #1
+ subs lr, lr, #1
+ orr r5, r5, r4, lsl #8
+ orr r6, r6, r5, lsl #8
+ orr r7, r7, r6, lsl #8
+ str r7, [r3], #4
+ bne 1b
+#endif
+
+ @ for (i = 0; i < 64; i++)
+ @ W[i+16] = ror(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 31);
+
+ sub r3, r2, #4
+ mov lr, #64
+2: ldr r4, [r3, #4]!
+ subs lr, lr, #1
+ ldr r5, [r3, #8]
+ ldr r6, [r3, #32]
+ ldr r7, [r3, #52]
+ eor r4, r4, r5
+ eor r4, r4, r6
+ eor r4, r4, r7
+ mov r4, r4, ror #31
+ str r4, [r3, #64]
+ bne 2b
+
+ /*
+ * The SHA functions are:
+ *
+ * f1(B,C,D) = (D ^ (B & (C ^ D)))
+ * f2(B,C,D) = (B ^ C ^ D)
+ * f3(B,C,D) = ((B & C) | (D & (B | C)))
+ *
+ * Then the sub-blocks are processed as follows:
+ *
+ * A' = ror(A, 27) + f(B,C,D) + E + K + *W++
+ * B' = A
+ * C' = ror(B, 2)
+ * D' = C
+ * E' = D
+ *
+ * We therefore unroll each loop 5 times to avoid register shuffling.
+ * Also the ror for C (and also D and E which are successivelyderived
+ * from it) is applied in place to cut on an additional mov insn for
+ * each round.
+ */
+
+ .macro sha_f1, A, B, C, D, E
+ ldr r3, [r2], #4
+ eor ip, \C, \D
+ add \E, r1, \E, ror #2
+ and ip, \B, ip, ror #2
+ add \E, \E, \A, ror #27
+ eor ip, ip, \D, ror #2
+ add \E, \E, r3
+ add \E, \E, ip
+ .endm
+
+ .macro sha_f2, A, B, C, D, E
+ ldr r3, [r2], #4
+ add \E, r1, \E, ror #2
+ eor ip, \B, \C, ror #2
+ add \E, \E, \A, ror #27
+ eor ip, ip, \D, ror #2
+ add \E, \E, r3
+ add \E, \E, ip
+ .endm
+
+ .macro sha_f3, A, B, C, D, E
+ ldr r3, [r2], #4
+ add \E, r1, \E, ror #2
+ orr ip, \B, \C, ror #2
+ add \E, \E, \A, ror #27
+ and ip, ip, \D, ror #2
+ add \E, \E, r3
+ and r3, \B, \C, ror #2
+ orr ip, ip, r3
+ add \E, \E, ip
+ .endm
+
+ ldmia r0, {r4 - r8}
+
+ mov lr, #4
+ ldr r1, .L_sha_K + 0
+
+ /* adjust initial values */
+ mov r6, r6, ror #30
+ mov r7, r7, ror #30
+ mov r8, r8, ror #30
+
+3: subs lr, lr, #1
+ sha_f1 r4, r5, r6, r7, r8
+ sha_f1 r8, r4, r5, r6, r7
+ sha_f1 r7, r8, r4, r5, r6
+ sha_f1 r6, r7, r8, r4, r5
+ sha_f1 r5, r6, r7, r8, r4
+ bne 3b
+
+ ldr r1, .L_sha_K + 4
+ mov lr, #4
+
+4: subs lr, lr, #1
+ sha_f2 r4, r5, r6, r7, r8
+ sha_f2 r8, r4, r5, r6, r7
+ sha_f2 r7, r8, r4, r5, r6
+ sha_f2 r6, r7, r8, r4, r5
+ sha_f2 r5, r6, r7, r8, r4
+ bne 4b
+
+ ldr r1, .L_sha_K + 8
+ mov lr, #4
+
+5: subs lr, lr, #1
+ sha_f3 r4, r5, r6, r7, r8
+ sha_f3 r8, r4, r5, r6, r7
+ sha_f3 r7, r8, r4, r5, r6
+ sha_f3 r6, r7, r8, r4, r5
+ sha_f3 r5, r6, r7, r8, r4
+ bne 5b
+
+ ldr r1, .L_sha_K + 12
+ mov lr, #4
+
+6: subs lr, lr, #1
+ sha_f2 r4, r5, r6, r7, r8
+ sha_f2 r8, r4, r5, r6, r7
+ sha_f2 r7, r8, r4, r5, r6
+ sha_f2 r6, r7, r8, r4, r5
+ sha_f2 r5, r6, r7, r8, r4
+ bne 6b
+
+ ldmia r0, {r1, r2, r3, ip, lr}
+ add r4, r1, r4
+ add r5, r2, r5
+ add r6, r3, r6, ror #2
+ add r7, ip, r7, ror #2
+ add r8, lr, r8, ror #2
+ stmia r0, {r4 - r8}
+
+ ldmfd sp!, {r4 - r8, pc}
+
+.L_sha_K:
+ .word 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6
+
projects / git.git / blobdiff