sha1c

SHA1 Choose

SHA1C <Qd>, <Sn>, <Vm>.<T>

SHA1 hash update (Choose function).

Pseudocode Operation

T ← SHA1_Choose(Sn)
Qd ← SHA1_Update_C(Qd, T, Vm)

Example

SHA1C q0, s1, v2.4s.T

Encoding

Binary Layout
01011110
31:24
00
23:22
0
21
Rm
20:16
0
15
000
14:12
00
11:10
Rn
9:5
Rd
4:0
 
Format Crypto
Opcode 0x5E000000
Extension Crypto

Operands

  • Qd
    State
  • Sn
    Hash
  • Vm
    Data

Related

Other forms of sha1c

More in Crypto

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding Instruction ISA Bit pattern
0x5E000000 SHA1C <Qd>, <Sn>, <Vm>.4S A64 01011110 | 00 | 0 | Rm | 0 | 000 | 00 | Rn | Rd

Description

SHA1 hash update (choose).

Operation

AArch64.CheckFPAdvSIMDEnabled();

bits(128) x = V[d, 128];
bits(32) y = V[n, 32];    // Note: 32 not 128 bits wide
bits(128) w = V[m, 128];
bits(32) t;

for e = 0 to 3
    t = SHAchoose(x<63:32>, x<95:64>, x<127:96>);
    y = y + ROL(x<31:0>, 5) + t + Elem[w, e, 32];
    x<63:32> = ROL(x<63:32>, 30);
    <y, x> = ROL(y:x, 32);
V[d, 128] = x;