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Diffstat (limited to 'arch/arm/crypto/blake2s-core.S')
| -rw-r--r-- | arch/arm/crypto/blake2s-core.S | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/arch/arm/crypto/blake2s-core.S b/arch/arm/crypto/blake2s-core.S new file mode 100644 index 000000000000..bed897e9a181 --- /dev/null +++ b/arch/arm/crypto/blake2s-core.S @@ -0,0 +1,285 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * BLAKE2s digest algorithm, ARM scalar implementation + * + * Copyright 2020 Google LLC + * + * Author: Eric Biggers <ebiggers@google.com> + */ + +#include <linux/linkage.h> + + // Registers used to hold message words temporarily. There aren't + // enough ARM registers to hold the whole message block, so we have to + // load the words on-demand. + M_0 .req r12 + M_1 .req r14 + +// The BLAKE2s initialization vector +.Lblake2s_IV: + .word 0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A + .word 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19 + +.macro __ldrd a, b, src, offset +#if __LINUX_ARM_ARCH__ >= 6 + ldrd \a, \b, [\src, #\offset] +#else + ldr \a, [\src, #\offset] + ldr \b, [\src, #\offset + 4] +#endif +.endm + +.macro __strd a, b, dst, offset +#if __LINUX_ARM_ARCH__ >= 6 + strd \a, \b, [\dst, #\offset] +#else + str \a, [\dst, #\offset] + str \b, [\dst, #\offset + 4] +#endif +.endm + +// Execute a quarter-round of BLAKE2s by mixing two columns or two diagonals. +// (a0, b0, c0, d0) and (a1, b1, c1, d1) give the registers containing the two +// columns/diagonals. s0-s1 are the word offsets to the message words the first +// column/diagonal needs, and likewise s2-s3 for the second column/diagonal. +// M_0 and M_1 are free to use, and the message block can be found at sp + 32. +// +// Note that to save instructions, the rotations don't happen when the +// pseudocode says they should, but rather they are delayed until the values are +// used. See the comment above _blake2s_round(). +.macro _blake2s_quarterround a0, b0, c0, d0, a1, b1, c1, d1, s0, s1, s2, s3 + + ldr M_0, [sp, #32 + 4 * \s0] + ldr M_1, [sp, #32 + 4 * \s2] + + // a += b + m[blake2s_sigma[r][2*i + 0]]; + add \a0, \a0, \b0, ror #brot + add \a1, \a1, \b1, ror #brot + add \a0, \a0, M_0 + add \a1, \a1, M_1 + + // d = ror32(d ^ a, 16); + eor \d0, \a0, \d0, ror #drot + eor \d1, \a1, \d1, ror #drot + + // c += d; + add \c0, \c0, \d0, ror #16 + add \c1, \c1, \d1, ror #16 + + // b = ror32(b ^ c, 12); + eor \b0, \c0, \b0, ror #brot + eor \b1, \c1, \b1, ror #brot + + ldr M_0, [sp, #32 + 4 * \s1] + ldr M_1, [sp, #32 + 4 * \s3] + + // a += b + m[blake2s_sigma[r][2*i + 1]]; + add \a0, \a0, \b0, ror #12 + add \a1, \a1, \b1, ror #12 + add \a0, \a0, M_0 + add \a1, \a1, M_1 + + // d = ror32(d ^ a, 8); + eor \d0, \a0, \d0, ror#16 + eor \d1, \a1, \d1, ror#16 + + // c += d; + add \c0, \c0, \d0, ror#8 + add \c1, \c1, \d1, ror#8 + + // b = ror32(b ^ c, 7); + eor \b0, \c0, \b0, ror#12 + eor \b1, \c1, \b1, ror#12 +.endm + +// Execute one round of BLAKE2s by updating the state matrix v[0..15]. v[0..9] +// are in r0..r9. The stack pointer points to 8 bytes of scratch space for +// spilling v[8..9], then to v[9..15], then to the message block. r10-r12 and +// r14 are free to use. The macro arguments s0-s15 give the order in which the +// message words are used in this round. +// +// All rotates are performed using the implicit rotate operand accepted by the +// 'add' and 'eor' instructions. This is faster than using explicit rotate +// instructions. To make this work, we allow the values in the second and last +// rows of the BLAKE2s state matrix (rows 'b' and 'd') to temporarily have the +// wrong rotation amount. The rotation amount is then fixed up just in time +// when the values are used. 'brot' is the number of bits the values in row 'b' +// need to be rotated right to arrive at the correct values, and 'drot' +// similarly for row 'd'. (brot, drot) start out as (0, 0) but we make it such +// that they end up as (7, 8) after every round. +.macro _blake2s_round s0, s1, s2, s3, s4, s5, s6, s7, \ + s8, s9, s10, s11, s12, s13, s14, s15 + + // Mix first two columns: + // (v[0], v[4], v[8], v[12]) and (v[1], v[5], v[9], v[13]). + __ldrd r10, r11, sp, 16 // load v[12] and v[13] + _blake2s_quarterround r0, r4, r8, r10, r1, r5, r9, r11, \ + \s0, \s1, \s2, \s3 + __strd r8, r9, sp, 0 + __strd r10, r11, sp, 16 + + // Mix second two columns: + // (v[2], v[6], v[10], v[14]) and (v[3], v[7], v[11], v[15]). + __ldrd r8, r9, sp, 8 // load v[10] and v[11] + __ldrd r10, r11, sp, 24 // load v[14] and v[15] + _blake2s_quarterround r2, r6, r8, r10, r3, r7, r9, r11, \ + \s4, \s5, \s6, \s7 + str r10, [sp, #24] // store v[14] + // v[10], v[11], and v[15] are used below, so no need to store them yet. + + .set brot, 7 + .set drot, 8 + + // Mix first two diagonals: + // (v[0], v[5], v[10], v[15]) and (v[1], v[6], v[11], v[12]). + ldr r10, [sp, #16] // load v[12] + _blake2s_quarterround r0, r5, r8, r11, r1, r6, r9, r10, \ + \s8, \s9, \s10, \s11 + __strd r8, r9, sp, 8 + str r11, [sp, #28] + str r10, [sp, #16] + + // Mix second two diagonals: + // (v[2], v[7], v[8], v[13]) and (v[3], v[4], v[9], v[14]). + __ldrd r8, r9, sp, 0 // load v[8] and v[9] + __ldrd r10, r11, sp, 20 // load v[13] and v[14] + _blake2s_quarterround r2, r7, r8, r10, r3, r4, r9, r11, \ + \s12, \s13, \s14, \s15 + __strd r10, r11, sp, 20 +.endm + +// +// void blake2s_compress_arch(struct blake2s_state *state, +// const u8 *block, size_t nblocks, u32 inc); +// +// Only the first three fields of struct blake2s_state are used: +// u32 h[8]; (inout) +// u32 t[2]; (inout) +// u32 f[2]; (in) +// + .align 5 +ENTRY(blake2s_compress_arch) + push {r0-r2,r4-r11,lr} // keep this an even number + +.Lnext_block: + // r0 is 'state' + // r1 is 'block' + // r3 is 'inc' + + // Load and increment the counter t[0..1]. + __ldrd r10, r11, r0, 32 + adds r10, r10, r3 + adc r11, r11, #0 + __strd r10, r11, r0, 32 + + // _blake2s_round is very short on registers, so copy the message block + // to the stack to save a register during the rounds. This also has the + // advantage that misalignment only needs to be dealt with in one place. + sub sp, sp, #64 + mov r12, sp + tst r1, #3 + bne .Lcopy_block_misaligned + ldmia r1!, {r2-r9} + stmia r12!, {r2-r9} + ldmia r1!, {r2-r9} + stmia r12, {r2-r9} +.Lcopy_block_done: + str r1, [sp, #68] // Update message pointer + + // Calculate v[8..15]. Push v[9..15] onto the stack, and leave space + // for spilling v[8..9]. Leave v[8..9] in r8-r9. + mov r14, r0 // r14 = state + adr r12, .Lblake2s_IV + ldmia r12!, {r8-r9} // load IV[0..1] + __ldrd r0, r1, r14, 40 // load f[0..1] + ldm r12, {r2-r7} // load IV[3..7] + eor r4, r4, r10 // v[12] = IV[4] ^ t[0] + eor r5, r5, r11 // v[13] = IV[5] ^ t[1] + eor r6, r6, r0 // v[14] = IV[6] ^ f[0] + eor r7, r7, r1 // v[15] = IV[7] ^ f[1] + push {r2-r7} // push v[9..15] + sub sp, sp, #8 // leave space for v[8..9] + + // Load h[0..7] == v[0..7]. + ldm r14, {r0-r7} + + // Execute the rounds. Each round is provided the order in which it + // needs to use the message words. + .set brot, 0 + .set drot, 0 + _blake2s_round 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 + _blake2s_round 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 + _blake2s_round 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 + _blake2s_round 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 + _blake2s_round 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 + _blake2s_round 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 + _blake2s_round 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 + _blake2s_round 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 + _blake2s_round 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 + _blake2s_round 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 + + // Fold the final state matrix into the hash chaining value: + // + // for (i = 0; i < 8; i++) + // h[i] ^= v[i] ^ v[i + 8]; + // + ldr r14, [sp, #96] // r14 = &h[0] + add sp, sp, #8 // v[8..9] are already loaded. + pop {r10-r11} // load v[10..11] + eor r0, r0, r8 + eor r1, r1, r9 + eor r2, r2, r10 + eor r3, r3, r11 + ldm r14, {r8-r11} // load h[0..3] + eor r0, r0, r8 + eor r1, r1, r9 + eor r2, r2, r10 + eor r3, r3, r11 + stmia r14!, {r0-r3} // store new h[0..3] + ldm r14, {r0-r3} // load old h[4..7] + pop {r8-r11} // load v[12..15] + eor r0, r0, r4, ror #brot + eor r1, r1, r5, ror #brot + eor r2, r2, r6, ror #brot + eor r3, r3, r7, ror #brot + eor r0, r0, r8, ror #drot + eor r1, r1, r9, ror #drot + eor r2, r2, r10, ror #drot + eor r3, r3, r11, ror #drot + add sp, sp, #64 // skip copy of message block + stm r14, {r0-r3} // store new h[4..7] + + // Advance to the next block, if there is one. Note that if there are + // multiple blocks, then 'inc' (the counter increment amount) must be + // 64. So we can simply set it to 64 without re-loading it. + ldm sp, {r0, r1, r2} // load (state, block, nblocks) + mov r3, #64 // set 'inc' + subs r2, r2, #1 // nblocks-- + str r2, [sp, #8] + bne .Lnext_block // nblocks != 0? + + pop {r0-r2,r4-r11,pc} + + // The next message block (pointed to by r1) isn't 4-byte aligned, so it + // can't be loaded using ldmia. Copy it to the stack buffer (pointed to + // by r12) using an alternative method. r2-r9 are free to use. +.Lcopy_block_misaligned: + mov r2, #64 +1: +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + ldr r3, [r1], #4 +#else + ldrb r3, [r1, #0] + ldrb r4, [r1, #1] + ldrb r5, [r1, #2] + ldrb r6, [r1, #3] + add r1, r1, #4 + orr r3, r3, r4, lsl #8 + orr r3, r3, r5, lsl #16 + orr r3, r3, r6, lsl #24 +#endif + subs r2, r2, #4 + str r3, [r12], #4 + bne 1b + b .Lcopy_block_done +ENDPROC(blake2s_compress_arch) |