Skip to content

Commit

Permalink
Improve variable names
Browse files Browse the repository at this point in the history 
To some extent anyway.

Signed-off-by: Gilles Peskine <[email protected]>
  • Loading branch information
@gilles-peskine-arm @tom-cosgrove-arm
gilles-peskine-arm authored and tom-cosgrove-arm committed Mar 17, 2023
1 parent 790756d commit d4a2393
Showing 1 changed file with 100 additions and 100 deletions.
200 changes: 100 additions & 100 deletions library/aesni.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,29 +89,29 @@ int mbedtls_aesni_crypt_ecb(mbedtls_aes_context *ctx,
unsigned nr = ctx->nr; // Number of remaining rounds

// Load round key 0
__m128i xmm0;
memcpy(&xmm0, input, 16);
xmm0 = _mm_xor_si128(xmm0, rk[0]); // xmm0 ^= *rk;
__m128i state;
memcpy(&state, input, 16);
state = _mm_xor_si128(state, rk[0]); // state ^= *rk;
++rk;
--nr;

if (mode == 0) {
while (nr != 0) {
xmm0 = _mm_aesdec_si128(xmm0, *rk);
state = _mm_aesdec_si128(state, *rk);
++rk;
--nr;
}
xmm0 = _mm_aesdeclast_si128(xmm0, *rk);
state = _mm_aesdeclast_si128(state, *rk);
} else {
while (nr != 0) {
xmm0 = _mm_aesenc_si128(xmm0, *rk);
state = _mm_aesenc_si128(state, *rk);
++rk;
--nr;
}
xmm0 = _mm_aesenclast_si128(xmm0, *rk);
state = _mm_aesenclast_si128(state, *rk);
}

memcpy(output, &xmm0, 16);
memcpy(output, &state, 16);
return 0;
}

Expand Down Expand Up @@ -141,25 +141,23 @@ static void gcm_clmul(const __m128i aa, const __m128i bb,

static void gcm_shift(__m128i *cc, __m128i *dd)
{
/*
* Now shift the result one bit to the left,
* taking advantage of [CLMUL-WP] eq 27 (p. 18)
*/
// // *cc = r1:r0
// // *dd = r3:r2
__m128i xmm1 = _mm_slli_epi64(*cc, 1); // r1<<1:r0<<1
__m128i xmm2 = _mm_slli_epi64(*dd, 1); // r3<<1:r2<<1
__m128i xmm3 = _mm_srli_epi64(*cc, 63); // r1>>63:r0>>63
__m128i xmm4 = _mm_srli_epi64(*dd, 63); // r3>>63:r2>>63
__m128i xmm5 = _mm_srli_si128(xmm3, 8); // 0:r1>>63
xmm3 = _mm_slli_si128(xmm3, 8); // r0>>63:0
xmm4 = _mm_slli_si128(xmm4, 8); // 0:r1>>63

*cc = _mm_or_si128(xmm1, xmm3); // r1<<1|r0>>63:r0<<1
*dd = _mm_or_si128(_mm_or_si128(xmm2, xmm4), xmm5); // r3<<1|r2>>62:r2<<1|r1>>63
/* [CMUCL-WP] Algorithm 5 Step 1: shift cc:dd one bit to the left,
* taking advantage of [CLMUL-WP] eq 27 (p. 18). */
// // *cc = r1:r0
// // *dd = r3:r2
__m128i cc_lo = _mm_slli_epi64(*cc, 1); // r1<<1:r0<<1
__m128i dd_lo = _mm_slli_epi64(*dd, 1); // r3<<1:r2<<1
__m128i cc_hi = _mm_srli_epi64(*cc, 63); // r1>>63:r0>>63
__m128i dd_hi = _mm_srli_epi64(*dd, 63); // r3>>63:r2>>63
__m128i xmm5 = _mm_srli_si128(cc_hi, 8); // 0:r1>>63
cc_hi = _mm_slli_si128(cc_hi, 8); // r0>>63:0
dd_hi = _mm_slli_si128(dd_hi, 8); // 0:r1>>63

*cc = _mm_or_si128(cc_lo, cc_hi); // r1<<1|r0>>63:r0<<1
*dd = _mm_or_si128(_mm_or_si128(dd_lo, dd_hi), xmm5); // r3<<1|r2>>62:r2<<1|r1>>63
}

static __m128i gcm_reduce1(__m128i xx)
static __m128i gcm_reduce(__m128i xx)
{
// // xx = x1:x0
/* [CLMUL-WP] Algorithm 5 Step 2 */
Expand All @@ -170,7 +168,7 @@ static __m128i gcm_reduce1(__m128i xx)
return _mm_xor_si128(dd, xx); // x1+a+b+c:x0 = d:x0
}

static __m128i gcm_reduce2(__m128i dx)
static __m128i gcm_mix(__m128i dx)
{
/* [CLMUL-WP] Algorithm 5 Steps 3 and 4 */
__m128i ee = _mm_srli_epi64(dx, 1); // e1:x0>>1 = e1:e0'
Expand Down Expand Up @@ -206,8 +204,8 @@ void mbedtls_aesni_gcm_mult(unsigned char c[16],
* using [CLMUL-WP] algorithm 5 (p. 18).
* Currently dd:cc holds x3:x2:x1:x0 (already shifted).
*/
__m128i dx = gcm_reduce1(cc);
__m128i xh = gcm_reduce2(dx);
__m128i dx = gcm_reduce(cc);
__m128i xh = gcm_mix(dx);
cc = _mm_xor_si128(xh, dd); // x3+h1:x2+h0

/* Now byte-reverse the outputs */
Expand Down Expand Up @@ -237,27 +235,27 @@ void mbedtls_aesni_inverse_key(unsigned char *invkey,
/*
* Key expansion, 128-bit case
*/
static __m128i aesni_set_rk_128(__m128i xmm0, __m128i xmm1)
static __m128i aesni_set_rk_128(__m128i state, __m128i xword)
{
/*
* Finish generating the next round key.
*
* On entry xmm0 is r3:r2:r1:r0 and xmm1 is X:stuff:stuff:stuff
* with X = rot( sub( r3 ) ) ^ RCON.
* On entry state is r3:r2:r1:r0 and xword is X:stuff:stuff:stuff
* with X = rot( sub( r3 ) ) ^ RCON (obtained with AESKEYGENASSIST).
*
* On exit, xmm1 is r7:r6:r5:r4
* On exit, xword is r7:r6:r5:r4
* with r4 = X + r0, r5 = r4 + r1, r6 = r5 + r2, r7 = r6 + r3
* and this is returned, to be written to the round key buffer.
*/
xmm1 = _mm_shuffle_epi32(xmm1, 0xff); // X:X:X:X
xmm1 = _mm_xor_si128(xmm1, xmm0); // X+r3:X+r2:X+r1:r4
xmm0 = _mm_slli_si128(xmm0, 4); // r2:r1:r0:0
xmm1 = _mm_xor_si128(xmm1, xmm0); // X+r3+r2:X+r2+r1:r5:r4
xmm0 = _mm_slli_si128(xmm0, 4); // r1:r0:0:0
xmm1 = _mm_xor_si128(xmm1, xmm0); // X+r3+r2+r1:r6:r5:r4
xmm0 = _mm_slli_si128(xmm0, 4); // r0:0:0:0
xmm1 = _mm_xor_si128(xmm1, xmm0); // r7:r6:r5:r4
return xmm1;
xword = _mm_shuffle_epi32(xword, 0xff); // X:X:X:X
xword = _mm_xor_si128(xword, state); // X+r3:X+r2:X+r1:r4
state = _mm_slli_si128(state, 4); // r2:r1:r0:0
xword = _mm_xor_si128(xword, state); // X+r3+r2:X+r2+r1:r5:r4
state = _mm_slli_si128(state, 4); // r1:r0:0:0
xword = _mm_xor_si128(xword, state); // X+r3+r2+r1:r6:r5:r4
state = _mm_slli_si128(state, 4); // r0:0:0:0
state = _mm_xor_si128(xword, state); // r7:r6:r5:r4
return state;
}

static void aesni_setkey_enc_128(unsigned char *rk_bytes,
Expand All @@ -281,39 +279,40 @@ static void aesni_setkey_enc_128(unsigned char *rk_bytes,
/*
* Key expansion, 192-bit case
*/
static void aesni_set_rk_192(__m128i *xmm0, __m128i *xmm1, __m128i xmm2,
static void aesni_set_rk_192(__m128i *state0, __m128i *state1, __m128i xword,
unsigned char *rk)
{
/*
* Finish generating the next 6 quarter-keys.
*
* On entry xmm0 is r3:r2:r1:r0, xmm1 is stuff:stuff:r5:r4
* and xmm2 is stuff:stuff:X:stuff with X = rot( sub( r3 ) ) ^ RCON.
* On entry state0 is r3:r2:r1:r0, state1 is stuff:stuff:r5:r4
* and xword is stuff:stuff:X:stuff with X = rot( sub( r3 ) ) ^ RCON
* (obtained with AESKEYGENASSIST).
*
* On exit, xmm0 is r9:r8:r7:r6 and xmm1 is stuff:stuff:r11:r10
* On exit, state0 is r9:r8:r7:r6 and state1 is stuff:stuff:r11:r10
* and those are written to the round key buffer.
*/
xmm2 = _mm_shuffle_epi32(xmm2, 0x55); // X:X:X:X
xmm2 = _mm_xor_si128(xmm2, *xmm0); // X+r3:X+r2:X+r1:X+r0
*xmm0 = _mm_slli_si128(*xmm0, 4); // r2:r1:r0:0
xmm2 = _mm_xor_si128(xmm2, *xmm0); // X+r3+r2:X+r2+r1:X+r1+r0:X+r0
*xmm0 = _mm_slli_si128(*xmm0, 4); // r1:r0:0:0
xmm2 = _mm_xor_si128(xmm2, *xmm0); // X+r3+r2+r1:X+r2+r1+r0:X+r1+r0:X+r0
*xmm0 = _mm_slli_si128(*xmm0, 4); // r0:0:0:0
xmm2 = _mm_xor_si128(xmm2, *xmm0); // X+r3+r2+r1+r0:X+r2+r1+r0:X+r1+r0:X+r0
*xmm0 = xmm2; // = r9:r8:r7:r6

xmm2 = _mm_shuffle_epi32(xmm2, 0xff); // r9:r9:r9:r9
xmm2 = _mm_xor_si128(xmm2, *xmm1); // stuff:stuff:r9+r5:r9+r4
*xmm1 = _mm_slli_si128(*xmm1, 4); // stuff:stuff:r4:0
xmm2 = _mm_xor_si128(xmm2, *xmm1); // stuff:stuff:r9+r5+r4:r9+r4
*xmm1 = xmm2; // = stuff:stuff:r11:r10

/* Store xmm0 and the low half of xmm1 into rk, which is conceptually
xword = _mm_shuffle_epi32(xword, 0x55); // X:X:X:X
xword = _mm_xor_si128(xword, *state0); // X+r3:X+r2:X+r1:X+r0
*state0 = _mm_slli_si128(*state0, 4); // r2:r1:r0:0
xword = _mm_xor_si128(xword, *state0); // X+r3+r2:X+r2+r1:X+r1+r0:X+r0
*state0 = _mm_slli_si128(*state0, 4); // r1:r0:0:0
xword = _mm_xor_si128(xword, *state0); // X+r3+r2+r1:X+r2+r1+r0:X+r1+r0:X+r0
*state0 = _mm_slli_si128(*state0, 4); // r0:0:0:0
xword = _mm_xor_si128(xword, *state0); // X+r3+r2+r1+r0:X+r2+r1+r0:X+r1+r0:X+r0
*state0 = xword; // = r9:r8:r7:r6

xword = _mm_shuffle_epi32(xword, 0xff); // r9:r9:r9:r9
xword = _mm_xor_si128(xword, *state1); // stuff:stuff:r9+r5:r9+r4
*state1 = _mm_slli_si128(*state1, 4); // stuff:stuff:r4:0
xword = _mm_xor_si128(xword, *state1); // stuff:stuff:r9+r5+r4:r9+r4
*state1 = xword; // = stuff:stuff:r11:r10

/* Store state0 and the low half of state1 into rk, which is conceptually
* an array of 24-byte elements. Since 24 is not a multiple of 16,
* rk is not necessarily aligned so just `*rk = *xmm0` doesn't work. */
memcpy(rk, xmm0, 16);
_mm_storeu_si64(rk + 16, *xmm1);
* rk is not necessarily aligned so just `*rk = *state0` doesn't work. */
memcpy(rk, state0, 16);
_mm_storeu_si64(rk + 16, *state1);
}

static void aesni_setkey_enc_192(unsigned char *rk,
Expand All @@ -322,55 +321,56 @@ static void aesni_setkey_enc_192(unsigned char *rk,
/* First round: use original key */
memcpy(rk, key, 24);
/* aes.c guarantees that rk is aligned on a 16-byte boundary. */
__m128i xmm0 = ((__m128i *) rk)[0];
__m128i xmm1 = _mm_loadl_epi64(((__m128i *) rk) + 1);

aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x01), rk + 24 * 1);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x02), rk + 24 * 2);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x04), rk + 24 * 3);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x08), rk + 24 * 4);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x10), rk + 24 * 5);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x20), rk + 24 * 6);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x40), rk + 24 * 7);
aesni_set_rk_192(&xmm0, &xmm1, _mm_aeskeygenassist_si128(xmm1, 0x80), rk + 24 * 8);
__m128i state0 = ((__m128i *) rk)[0];
__m128i state1 = _mm_loadl_epi64(((__m128i *) rk) + 1);

aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x01), rk + 24 * 1);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x02), rk + 24 * 2);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x04), rk + 24 * 3);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x08), rk + 24 * 4);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x10), rk + 24 * 5);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x20), rk + 24 * 6);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x40), rk + 24 * 7);
aesni_set_rk_192(&state0, &state1, _mm_aeskeygenassist_si128(state1, 0x80), rk + 24 * 8);
}

/*
* Key expansion, 256-bit case
*/
static void aesni_set_rk_256(__m128i xmm0, __m128i xmm1, __m128i xmm2,
static void aesni_set_rk_256(__m128i state0, __m128i state1, __m128i xword,
__m128i *rk0, __m128i *rk1)
{
/*
* Finish generating the next two round keys.
*
* On entry xmm0 is r3:r2:r1:r0, xmm1 is r7:r6:r5:r4 and
* xmm2 is X:stuff:stuff:stuff with X = rot( sub( r7 )) ^ RCON
* On entry state0 is r3:r2:r1:r0, state1 is r7:r6:r5:r4 and
* xword is X:stuff:stuff:stuff with X = rot( sub( r7 )) ^ RCON
* (obtained with AESKEYGENASSIST).
*
* On exit, *rk0 is r11:r10:r9:r8 and *rk1 is r15:r14:r13:r12
*/
xmm2 = _mm_shuffle_epi32(xmm2, 0xff);
xmm2 = _mm_xor_si128(xmm2, xmm0);
xmm0 = _mm_slli_si128(xmm0, 4);
xmm2 = _mm_xor_si128(xmm2, xmm0);
xmm0 = _mm_slli_si128(xmm0, 4);
xmm2 = _mm_xor_si128(xmm2, xmm0);
xmm0 = _mm_slli_si128(xmm0, 4);
xmm0 = _mm_xor_si128(xmm0, xmm2);
*rk0 = xmm0;

/* Set xmm2 to stuff:Y:stuff:stuff with Y = subword( r11 )
xword = _mm_shuffle_epi32(xword, 0xff);
xword = _mm_xor_si128(xword, state0);
state0 = _mm_slli_si128(state0, 4);
xword = _mm_xor_si128(xword, state0);
state0 = _mm_slli_si128(state0, 4);
xword = _mm_xor_si128(xword, state0);
state0 = _mm_slli_si128(state0, 4);
state0 = _mm_xor_si128(state0, xword);
*rk0 = state0;

/* Set xword to stuff:Y:stuff:stuff with Y = subword( r11 )
* and proceed to generate next round key from there */
xmm2 = _mm_aeskeygenassist_si128(xmm0, 0x00);
xmm2 = _mm_shuffle_epi32(xmm2, 0xaa);
xmm2 = _mm_xor_si128(xmm2, xmm1);
xmm1 = _mm_slli_si128(xmm1, 4);
xmm2 = _mm_xor_si128(xmm2, xmm1);
xmm1 = _mm_slli_si128(xmm1, 4);
xmm2 = _mm_xor_si128(xmm2, xmm1);
xmm1 = _mm_slli_si128(xmm1, 4);
xmm1 = _mm_xor_si128(xmm1, xmm2);
*rk1 = xmm1;
xword = _mm_aeskeygenassist_si128(state0, 0x00);
xword = _mm_shuffle_epi32(xword, 0xaa);
xword = _mm_xor_si128(xword, state1);
state1 = _mm_slli_si128(state1, 4);
xword = _mm_xor_si128(xword, state1);
state1 = _mm_slli_si128(state1, 4);
xword = _mm_xor_si128(xword, state1);
state1 = _mm_slli_si128(state1, 4);
state1 = _mm_xor_si128(state1, xword);
*rk1 = state1;
}

static void aesni_setkey_enc_256(unsigned char *rk_bytes,
Expand Down

0 comments on commit d4a2393

Please sign in to comment.