ref: 74d91a0021de012908cfdb35fb61a1473a376130
dir: /lib/crypto/chacha20.myr/
use std pkg crypto = type chacha20ctx = struct input : uint32[16] ;; const chacha20keysetup : (x : chacha20ctx#, k : byte[:] -> void) const chacha20ivsetup : (x : chacha20ctx#, iv : byte[:] -> void) const chacha20encrypt : (x : chacha20ctx#, m : byte[:], c : byte[:] -> void) ;; const sigma = "expand 32-byte k" const tau = "expand 16-byte k" const chacha20keysetup = {x, k var constants x.input[4] = std.getle32(k[0:4]) x.input[5] = std.getle32(k[4:8]) x.input[6] = std.getle32(k[8:12]) x.input[7] = std.getle32(k[12:16]) if k.len * 8 == 256 k = k[16:] constants = sigma elif k.len * 8 == 128 constants = tau else std.die("invalid key length") ;; x.input[8] = std.getle32(k[0:4]) x.input[9] = std.getle32(k[4:8]) x.input[10] = std.getle32(k[8:12]) x.input[11] = std.getle32(k[12:16]) x.input[0] = std.getle32(constants[0:4]) x.input[1] = std.getle32(constants[4:8]) x.input[2] = std.getle32(constants[8:12]) x.input[3] = std.getle32(constants[12:16]) } const chacha20ivsetup = {x, iv x.input[12] = 0 x.input[13] = 0 x.input[14] = std.getle32(iv[0:4]) x.input[15] = std.getle32(iv[4:8]) } const chacha20encrypt = {x, m, c var x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15 : uint32; var j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15 : uint32; var ctarget = [][:] var tmp : byte[64]; std.assert(m.len == c.len, "mismatch between message and ciphertext lengths\n") j0 = x.input[0] j1 = x.input[1] j2 = x.input[2] j3 = x.input[3] j4 = x.input[4] j5 = x.input[5] j6 = x.input[6] j7 = x.input[7] j8 = x.input[8] j9 = x.input[9] j10 = x.input[10] j11 = x.input[11] j12 = x.input[12] j13 = x.input[13] j14 = x.input[14] j15 = x.input[15] while true if m.len < 64 std.slcp(tmp[:m.len], m) m = tmp[:] ctarget = c c = tmp[:] ;; x0 = j0 x1 = j1 x2 = j2 x3 = j3 x4 = j4 x5 = j5 x6 = j6 x7 = j7 x8 = j8 x9 = j9 x10 = j10 x11 = j11 x12 = j12 x13 = j13 x14 = j14 x15 = j15 /* do the rounds */ for var i = 20; i > 0; i -= 2 x0 = (x0 + x4) x12 = (((x12 ^ x0 : uint32) << 16) | ((x12 ^ x0) >> (32 - 16))) x8 = (x8 + x12) x4 = (((x4 ^ x8 : uint32) << 12) | ((x4 ^ x8) >> (32 - 12))) x0 = (x0 + x4) x12 = (((x12 ^ x0 : uint32) << 8) | ((x12 ^ x0) >> (32 - 8))) x8 = (x8 + x12) x4 = (((x4 ^ x8 : uint32) << 7) | ((x4 ^ x8) >> (32 - 7))) x1 = (x1 + x5) x13 = ((((x13 ^ x1) : uint32) << 16) | ((x13 ^ x1) >> (32 - 16))) x9 = (x9 + x13) x5 = ((((x5 ^ x9) : uint32) << 12) | ((x5 ^ x9) >> (32 - 12))) x1 = (x1 + x5) x13 = ((((x13 ^ x1) : uint32) << 8) | ((x13 ^ x1) >> (32 - 8))) x9 = (x9 + x13) x5 = ((((x5 ^ x9) : uint32) << 7) | ((x5 ^ x9) >> (32 - 7))) x2 = (x2 + x6) x14 = ((((x14 ^ x2) : uint32) << 16) | ((x14 ^ x2) >> (32 - 16))) x10 = (x10 + x14) x6 = ((((x6 ^ x10) : uint32) << 12) | ((x6 ^ x10) >> (32 - 12))) x2 = (x2 + x6) x14 = ((((x14 ^ x2) : uint32) << 8) | ((x14 ^ x2) >> (32 - 8))) x10 = (x10 + x14) x6 = ((((x6 ^ x10) : uint32) << 7) | ((x6 ^ x10) >> (32 - 7))) x3 = (x3 + x7) x15 = ((((x15 ^ x3) : uint32) << 16) | ((x15 ^ x3) >> (32 - 16))) x11 = (x11 + x15) x7 = ((((x7 ^ x11) : uint32) << 12) | ((x7 ^ x11) >> (32 - 12))) x3 = (x3 + x7) x15 = ((((x15 ^ x3) : uint32) << 8) | ((x15 ^ x3) >> (32 - 8))) x11 = (x11 + x15) x7 = ((((x7 ^ x11) : uint32) << 7) | ((x7 ^ x11) >> (32 - 7))) x0 = (x0 + x5) x15 = ((((x15 ^ x0) : uint32) << 16) | ((x15 ^ x0) >> (32 - 16))) x10 = (x10 + x15) x5 = ((((x5 ^ x10) : uint32) << 12) | ((x5 ^ x10) >> (32 - 12))) x0 = (x0 + x5) x15 = ((((x15 ^ x0) : uint32) << 8) | ((x15 ^ x0) >> (32 - 8))) x10 = (x10 + x15) x5 = ((((x5 ^ x10) : uint32) << 7) | ((x5 ^ x10) >> (32 - 7))) x1 = (x1 + x6) x12 = ((((x12 ^ x1) : uint32) << 16) | ((x12 ^ x1) >> (32 - 16))) x11 = (x11 + x12) x6 = ((((x6 ^ x11) : uint32) << 12) | ((x6 ^ x11) >> (32 - 12))) x1 = (x1 + x6) x12 = ((((x12 ^ x1) : uint32) << 8) | ((x12 ^ x1) >> (32 - 8))) x11 = (x11 + x12) x6 = ((((x6 ^ x11) : uint32) << 7) | ((x6 ^ x11) >> (32 - 7))) x2 = (x2 + x7) x13 = ((((x13 ^ x2) : uint32) << 16) | ((x13 ^ x2) >> (32 - 16))) x8 = (x8 + x13) x7 = ((((x7 ^ x8) : uint32) << 12) | ((x7 ^ x8) >> (32 - 12))) x2 = (x2 + x7) x13 = ((((x13 ^ x2) : uint32) << 8) | ((x13 ^ x2) >> (32 - 8))) x8 = (x8 + x13) x7 = ((((x7 ^ x8) : uint32) << 7) | ((x7 ^ x8) >> (32 - 7))) x3 = (x3 + x4) x14 = ((((x14 ^ x3) : uint32) << 16) | ((x14 ^ x3) >> (32 - 16))) x9 = (x9 + x14) x4 = ((((x4 ^ x9) : uint32) << 12) | ((x4 ^ x9) >> (32 - 12))) x3 = (x3 + x4) x14 = ((((x14 ^ x3) : uint32) << 8) | ((x14 ^ x3) >> (32 - 8))) x9 = (x9 + x14) x4 = ((((x4 ^ x9) : uint32) << 7) | ((x4 ^ x9) >> (32 - 7))) ;; x0 = x0 + j0 x1 = x1 + j1 x2 = x2 + j2 x3 = x3 + j3 x4 = x4 + j4 x5 = x5 + j5 x6 = x6 + j6 x7 = x7 + j7 x8 = x8 + j8 x9 = x9 + j9 x10 = x10 + j10 x11 = x11 + j11 x12 = x12 + j12 x13 = x13 + j13 x14 = x14 + j14 x15 = x15 + j15 x0 = x0 ^ std.getle32(m[0:4]); x1 = x1 ^ std.getle32(m[4:8]); x2 = x2 ^ std.getle32(m[8:12]); x3 = x3 ^ std.getle32(m[12:16]); x4 = x4 ^ std.getle32(m[16:20]); x5 = x5 ^ std.getle32(m[20:24]); x6 = x6 ^ std.getle32(m[24:28]); x7 = x7 ^ std.getle32(m[28:32]); x8 = x8 ^ std.getle32(m[32:36]); x9 = x9 ^ std.getle32(m[36:40]); x10 = x10 ^ std.getle32(m[40:44]); x11 = x11 ^ std.getle32(m[44:48]); x12 = x12 ^ std.getle32(m[48:52]); x13 = x13 ^ std.getle32(m[52:56]); x14 = x14 ^ std.getle32(m[56:60]); x15 = x15 ^ std.getle32(m[60:64]); j12++ if j12 == 0 j13++ ;; std.putle32(c[0:4], x0); std.putle32(c[4:8], x1); std.putle32(c[8:12], x2); std.putle32(c[12:16], x3); std.putle32(c[16:20], x4); std.putle32(c[20:24], x5); std.putle32(c[24:28], x6); std.putle32(c[28:32], x7); std.putle32(c[32:36], x8); std.putle32(c[36:40], x9); std.putle32(c[40:44], x10); std.putle32(c[44:48], x11); std.putle32(c[48:52], x12); std.putle32(c[52:56], x13); std.putle32(c[56:60], x14); std.putle32(c[60:64], x15); if m.len <= 64 if m.len < 64 std.slcp(ctarget[:m.len], c) ;; x.input[12] = j12; x.input[13] = j13; -> void ;; c = c[64:] m = m[64:] ;; }