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author | Denys Vlasenko | 2021-10-05 20:00:50 +0200 |
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committer | Denys Vlasenko | 2021-10-05 20:01:38 +0200 |
commit | 3b411ebbfc749f9f12b0eb739cb5ba3ec052197e (patch) | |
tree | da81f1546b78d25f4ac63e612e76cb27aa4c2db3 /networking | |
parent | 55578f2fb7c05357fb0b1ce84b616ba8ffd6d907 (diff) | |
download | busybox-3b411ebbfc749f9f12b0eb739cb5ba3ec052197e.zip busybox-3b411ebbfc749f9f12b0eb739cb5ba3ec052197e.tar.gz |
tls: replace "26-bit" P256 code with 32-bit one.
function old new delta
sp_256_ecc_mulmod_8 - 1171 +1171
sp_256_mod_mul_norm_8 - 834 +834
sp_256_proj_point_dbl_8 - 374 +374
sp_256_mont_reduce_8 - 268 +268
sp_256_mont_mul_8 - 151 +151
sp_256_sub_8 - 76 +76
sp_256_add_8 - 76 +76
sp_256_cmp_8 - 38 +38
static.sp_256_mont_dbl_8 - 31 +31
static.sp_256_mont_sub_8 - 29 +29
sp_256_to_bin_8 - 28 +28
sp_256_point_from_bin2x32 50 73 +23
sp_256_mont_sqr_8 - 7 +7
sp_256_mont_sqr_10 7 - -7
p256_mod 40 32 -8
curve_P256_compute_pubkey_and_premaster 186 167 -19
sp_256_sub_10 22 - -22
sp_256_add_10 22 - -22
sp_256_cmp_10 24 - -24
sp_256_norm_10 31 - -31
static.sp_256_mont_sub_10 49 - -49
static.sp_256_mont_dbl_10 52 - -52
static.sp_256_mul_add_10 82 - -82
sp_256_from_bin_10 119 - -119
sp_256_to_bin_10 120 - -120
sp_256_mont_reduce_10 178 - -178
sp_256_mont_mul_10 214 - -214
sp_256_proj_point_dbl_10 451 - -451
sp_256_ecc_mulmod_10 1216 - -1216
sp_256_mod_mul_norm_10 1305 - -1305
------------------------------------------------------------------------------
(add/remove: 12/15 grow/shrink: 1/2 up/down: 3106/-3919) Total: -813 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking')
-rw-r--r-- | networking/tls.c | 15 | ||||
-rw-r--r-- | networking/tls_sp_c32.c | 1071 |
2 files changed, 588 insertions, 498 deletions
diff --git a/networking/tls.c b/networking/tls.c index 4f0e2b6..675ef4b 100644 --- a/networking/tls.c +++ b/networking/tls.c @@ -2334,7 +2334,6 @@ void FAST_FUNC tls_run_copy_loop(tls_state_t *tls, unsigned flags) // e.g. at the very beginning of wget_main() // { -//kbuild:lib-$(CONFIG_TLS) += tls_sp_c32_new.o uint8_t ecc_pub_key32[2 * 32]; uint8_t pubkey2x32[2 * 32]; uint8_t premaster32[32]; @@ -2345,14 +2344,14 @@ void FAST_FUNC tls_run_copy_loop(tls_state_t *tls, unsigned flags) // memset(ecc_pub_key32, 0x00, sizeof(ecc_pub_key32)); // ecc_pub_key32[18] = 0xab; //Random key: - tls_get_random(ecc_pub_key32, sizeof(ecc_pub_key32)); +// tls_get_random(ecc_pub_key32, sizeof(ecc_pub_key32)); //Biased random (almost all zeros or almost all ones): -// srand(time(NULL) ^ getpid()); -// if (rand() & 1) -// memset(ecc_pub_key32, 0x00, sizeof(ecc_pub_key32)); -// else -// memset(ecc_pub_key32, 0xff, sizeof(ecc_pub_key32)); -// ecc_pub_key32[rand() & 0x3f] = rand(); + srand(time(NULL) ^ getpid()); + if (rand() & 1) + memset(ecc_pub_key32, 0x00, sizeof(ecc_pub_key32)); + else + memset(ecc_pub_key32, 0xff, sizeof(ecc_pub_key32)); + ecc_pub_key32[rand() & 0x3f] = rand(); xmove_fd(xopen("p256.OLD", O_WRONLY | O_CREAT | O_TRUNC), 2); curve_P256_compute_pubkey_and_premaster( diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c index bba22de..b999518 100644 --- a/networking/tls_sp_c32.c +++ b/networking/tls_sp_c32.c @@ -9,6 +9,8 @@ #define FIXED_SECRET 0 #define FIXED_PEER_PUBKEY 0 +#define ALLOW_ASM 1 + #if SP_DEBUG # define dbg(...) fprintf(stderr, __VA_ARGS__) static void dump_hex(const char *fmt, const void *vp, int len) @@ -24,7 +26,8 @@ static void dump_hex(const char *fmt, const void *vp, int len) # define dump_hex(...) ((void)0) #endif -typedef int32_t sp_digit; +typedef uint32_t sp_digit; +typedef int32_t signed_sp_digit; /* The code below is taken from parts of * wolfssl-3.15.3/wolfcrypt/src/sp_c32.c @@ -32,53 +35,23 @@ typedef int32_t sp_digit; * Header comment is kept intact: */ -/* sp.c - * - * Copyright (C) 2006-2018 wolfSSL Inc. - * - * This file is part of wolfSSL. - * - * wolfSSL is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * wolfSSL is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA - */ - -/* Implementation by Sean Parkinson. */ - typedef struct sp_point { - sp_digit x[2 * 10]; - sp_digit y[2 * 10]; - sp_digit z[2 * 10]; + sp_digit x[2 * 8]; + sp_digit y[2 * 8]; + sp_digit z[2 * 8]; int infinity; } sp_point; /* The modulus (prime) of the curve P256. */ -static const sp_digit p256_mod[10] = { - 0x3ffffff,0x3ffffff,0x3ffffff,0x003ffff,0x0000000, - 0x0000000,0x0000000,0x0000400,0x3ff0000,0x03fffff, +static const sp_digit p256_mod[8] = { + 0xffffffff,0xffffffff,0xffffffff,0x00000000, + 0x00000000,0x00000000,0x00000001,0xffffffff, }; #define p256_mp_mod ((sp_digit)0x000001) -/* Normalize the values in each word to 26 bits. */ -static void sp_256_norm_10(sp_digit* a) -{ - int i; - for (i = 0; i < 9; i++) { - a[i+1] += a[i] >> 26; - a[i] &= 0x3ffffff; - } -} +/* Normalize the values in each word to 32 bits - NOP */ +#define sp_256_norm_8(a) ((void)0) /* Write r as big endian to byte array. * Fixed length number of bytes written: 32 @@ -86,31 +59,17 @@ static void sp_256_norm_10(sp_digit* a) * r A single precision integer. * a Byte array. */ -static void sp_256_to_bin_10(sp_digit* r, uint8_t* a) -{ - int i, j, s = 0, b; - - sp_256_norm_10(r); - - j = 256 / 8 - 1; - a[j] = 0; - for (i = 0; i < 10 && j >= 0; i++) { - b = 0; - a[j--] |= r[i] << s; - b += 8 - s; - if (j < 0) - break; - while (b < 26) { - a[j--] = r[i] >> b; - b += 8; - if (j < 0) - break; - } - s = 8 - (b - 26); - if (j >= 0) - a[j] = 0; - if (s != 0) - j++; +static void sp_256_to_bin_8(const sp_digit* r, uint8_t* a) +{ + int i; + + sp_256_norm_8(r); + + r += 8; + for (i = 0; i < 8; i++) { + r--; + move_to_unaligned32(a, SWAP_BE32(*r)); + a += 4; } } @@ -120,67 +79,32 @@ static void sp_256_to_bin_10(sp_digit* r, uint8_t* a) * a Byte array. * n Number of bytes in array to read. */ -static void sp_256_from_bin_10(sp_digit* r, const uint8_t* a) -{ - int i, j = 0, s = 0; - - r[0] = 0; - for (i = 32 - 1; i >= 0; i--) { - r[j] |= ((sp_digit)a[i]) << s; - if (s >= 18) { - r[j] &= 0x3ffffff; - s = 26 - s; - r[++j] = a[i] >> s; - s = 8 - s; - } - else - s += 8; +static void sp_256_from_bin_8(sp_digit* r, const uint8_t* a) +{ + int i; + + r += 8; + for (i = 0; i < 8; i++) { + sp_digit v; + move_from_unaligned32(v, a); + *--r = SWAP_BE32(v); + a += 4; } } #if SP_DEBUG -static void dump_256(const char *fmt, const sp_digit* cr) +static void dump_256(const char *fmt, const sp_digit* r) { - sp_digit* r = (sp_digit*)cr; uint8_t b32[32]; - sp_256_to_bin_10(r, b32); + sp_256_to_bin_8(r, b32); dump_hex(fmt, b32, 32); } -static void dump_512(const char *fmt, const sp_digit* cr) +static void dump_512(const char *fmt, const sp_digit* r) { - sp_digit* r = (sp_digit*)cr; - uint8_t a[64]; - int i, j, s, b; - - /* sp_512_norm_10: */ - for (i = 0; i < 19; i++) { - r[i+1] += r[i] >> 26; - r[i] &= 0x3ffffff; - } - /* sp_512_to_bin_10: */ - s = 0; - j = 512 / 8 - 1; - a[j] = 0; - for (i = 0; i < 20 && j >= 0; i++) { - b = 0; - a[j--] |= r[i] << s; - b += 8 - s; - if (j < 0) - break; - while (b < 26) { - a[j--] = r[i] >> b; - b += 8; - if (j < 0) - break; - } - s = 8 - (b - 26); - if (j >= 0) - a[j] = 0; - if (s != 0) - j++; - } - - dump_hex(fmt, a, 64); + uint8_t b64[64]; + sp_256_to_bin_8(r, b64 + 32); + sp_256_to_bin_8(r+8, b64); + dump_hex(fmt, b64, 64); } #else # define dump_256(...) ((void)0) @@ -192,8 +116,8 @@ static void sp_256_point_from_bin2x32(sp_point* p, const uint8_t *bin2x32) { memset(p, 0, sizeof(*p)); /*p->infinity = 0;*/ - sp_256_from_bin_10(p->x, bin2x32); - sp_256_from_bin_10(p->y, bin2x32 + 32); + sp_256_from_bin_8(p->x, bin2x32); + sp_256_from_bin_8(p->y, bin2x32 + 32); p->z[0] = 1; /* p->z = 1 */ } @@ -202,170 +126,303 @@ static void sp_256_point_from_bin2x32(sp_point* p, const uint8_t *bin2x32) * return -ve, 0 or +ve if a is less than, equal to or greater than b * respectively. */ -static sp_digit sp_256_cmp_10(const sp_digit* a, const sp_digit* b) +static signed_sp_digit sp_256_cmp_8(const sp_digit* a, const sp_digit* b) { - sp_digit r; int i; - for (i = 9; i >= 0; i--) { - r = a[i] - b[i]; - if (r != 0) - break; + for (i = 7; i >= 0; i--) { +/* signed_sp_digit r = a[i] - b[i]; + * if (r != 0) + * return r; + * does not work: think about a[i]=0, b[i]=0xffffffff + */ + if (a[i] == b[i]) + continue; + return (a[i] > b[i]) * 2 - 1; } - return r; + return 0; } /* Compare two numbers to determine if they are equal. * * return 1 when equal and 0 otherwise. */ -static int sp_256_cmp_equal_10(const sp_digit* a, const sp_digit* b) +static int sp_256_cmp_equal_8(const sp_digit* a, const sp_digit* b) { - return sp_256_cmp_10(a, b) == 0; + return sp_256_cmp_8(a, b) == 0; } -/* Add b to a into r. (r = a + b) */ -static void sp_256_add_10(sp_digit* r, const sp_digit* a, const sp_digit* b) +/* Add b to a into r. (r = a + b). Return !0 on overflow */ +static int sp_256_add_8(sp_digit* r, const sp_digit* a, const sp_digit* b) { +#if ALLOW_ASM && defined(__GNUC__) && defined(__i386__) + sp_digit reg; + asm volatile ( +"\n movl (%0), %3" +"\n addl (%1), %3" +"\n movl %3, (%2)" +"\n" +"\n movl 1*4(%0), %3" +"\n adcl 1*4(%1), %3" +"\n movl %3, 1*4(%2)" +"\n" +"\n movl 2*4(%0), %3" +"\n adcl 2*4(%1), %3" +"\n movl %3, 2*4(%2)" +"\n" +"\n movl 3*4(%0), %3" +"\n adcl 3*4(%1), %3" +"\n movl %3, 3*4(%2)" +"\n" +"\n movl 4*4(%0), %3" +"\n adcl 4*4(%1), %3" +"\n movl %3, 4*4(%2)" +"\n" +"\n movl 5*4(%0), %3" +"\n adcl 5*4(%1), %3" +"\n movl %3, 5*4(%2)" +"\n" +"\n movl 6*4(%0), %3" +"\n adcl 6*4(%1), %3" +"\n movl %3, 6*4(%2)" +"\n" +"\n movl 7*4(%0), %3" +"\n adcl 7*4(%1), %3" +"\n movl %3, 7*4(%2)" +"\n" +"\n sbbl %3, %3" +"\n" + : "=r" (a), "=r" (b), "=r" (r), "=r" (reg) + : "0" (a), "1" (b), "2" (r) + : "memory" + ); + return reg; +#else int i; - for (i = 0; i < 10; i++) - r[i] = a[i] + b[i]; + sp_digit carry; + + carry = 0; + for (i = 0; i < 8; i++) { + sp_digit w, v; + w = b[i] + carry; + v = a[i]; + if (w != 0) { + v = a[i] + w; + carry = (v < a[i]); + /* hope compiler detects above as "carry flag set" */ + } + /* else: b + carry == 0, two cases: + * b:ffffffff, carry:1 + * b:00000000, carry:0 + * in either case, r[i] = a[i] and carry remains unchanged + */ + r[i] = v; + } + return carry; +#endif } -/* Sub b from a into r. (r = a - b) */ -static void sp_256_sub_10(sp_digit* r, const sp_digit* a, const sp_digit* b) +/* Sub b from a into r. (r = a - b). Return !0 on underflow */ +static int sp_256_sub_8(sp_digit* r, const sp_digit* a, const sp_digit* b) { +#if ALLOW_ASM && defined(__GNUC__) && defined(__i386__) + sp_digit reg; + asm volatile ( +"\n movl (%0), %3" +"\n subl (%1), %3" +"\n movl %3, (%2)" +"\n" +"\n movl 1*4(%0), %3" +"\n sbbl 1*4(%1), %3" +"\n movl %3, 1*4(%2)" +"\n" +"\n movl 2*4(%0), %3" +"\n sbbl 2*4(%1), %3" +"\n movl %3, 2*4(%2)" +"\n" +"\n movl 3*4(%0), %3" +"\n sbbl 3*4(%1), %3" +"\n movl %3, 3*4(%2)" +"\n" +"\n movl 4*4(%0), %3" +"\n sbbl 4*4(%1), %3" +"\n movl %3, 4*4(%2)" +"\n" +"\n movl 5*4(%0), %3" +"\n sbbl 5*4(%1), %3" +"\n movl %3, 5*4(%2)" +"\n" +"\n movl 6*4(%0), %3" +"\n sbbl 6*4(%1), %3" +"\n movl %3, 6*4(%2)" +"\n" +"\n movl 7*4(%0), %3" +"\n sbbl 7*4(%1), %3" +"\n movl %3, 7*4(%2)" +"\n" +"\n sbbl %3, %3" +"\n" + : "=r" (a), "=r" (b), "=r" (r), "=r" (reg) + : "0" (a), "1" (b), "2" (r) + : "memory" + ); + return reg; +#else int i; - for (i = 0; i < 10; i++) - r[i] = a[i] - b[i]; + sp_digit borrow; + + borrow = 0; + for (i = 0; i < 8; i++) { + sp_digit w, v; + w = b[i] + borrow; + v = a[i]; + if (w != 0) { + v = a[i] - w; + borrow = (v > a[i]); + /* hope compiler detects above as "carry flag set" */ + } + /* else: b + borrow == 0, two cases: + * b:ffffffff, borrow:1 + * b:00000000, borrow:0 + * in either case, r[i] = a[i] and borrow remains unchanged + */ + r[i] = v; + } + return borrow; +#endif } /* Multiply a and b into r. (r = a * b) */ -static void sp_256_mul_10(sp_digit* r, const sp_digit* a, const sp_digit* b) +static void sp_256_mul_8(sp_digit* r, const sp_digit* a, const sp_digit* b) { + sp_digit rr[15]; /* in case r coincides with a or b */ int i, j, k; - int64_t c; - - c = ((int64_t)a[9]) * b[9]; - r[19] = (sp_digit)(c >> 26); - c = (c & 0x3ffffff) << 26; - for (k = 17; k >= 0; k--) { - for (i = 9; i >= 0; i--) { - j = k - i; - if (j >= 10) - break; - if (j < 0) - continue; - c += ((int64_t)a[i]) * b[j]; + uint64_t acc; + + acc = 0; + for (k = 0; k < 15; k++) { + uint32_t acc_hi; + i = k - 7; + if (i < 0) + i = 0; + j = k - i; + acc_hi = 0; + while (i != 8 && i <= k) { + uint64_t m = ((uint64_t)a[i]) * b[j]; + acc += m; + if (acc < m) + acc_hi++; + j--; + i++; } - r[k + 2] += c >> 52; - r[k + 1] = (c >> 26) & 0x3ffffff; - c = (c & 0x3ffffff) << 26; + rr[k] = acc; + acc = (acc >> 32) | ((uint64_t)acc_hi << 32); } - r[0] = (sp_digit)(c >> 26); + r[15] = acc; + memcpy(r, rr, sizeof(rr)); } /* Shift number right one bit. Bottom bit is lost. */ -static void sp_256_rshift1_10(sp_digit* r, sp_digit* a) +static void sp_256_rshift1_8(sp_digit* r, sp_digit* a, sp_digit carry) { int i; - for (i = 0; i < 9; i++) - r[i] = ((a[i] >> 1) | (a[i + 1] << 25)) & 0x3ffffff; - r[9] = a[9] >> 1; + + carry = (!!carry << 31); + for (i = 7; i >= 0; i--) { + sp_digit c = a[i] << 31; + r[i] = (a[i] >> 1) | carry; + carry = c; + } } /* Divide the number by 2 mod the modulus (prime). (r = a / 2 % m) */ -static void sp_256_div2_10(sp_digit* r, const sp_digit* a, const sp_digit* m) +static void sp_256_div2_8(sp_digit* r, const sp_digit* a, const sp_digit* m) { + int carry = 0; if (a[0] & 1) - sp_256_add_10(r, a, m); - sp_256_norm_10(r); - sp_256_rshift1_10(r, r); + carry = sp_256_add_8(r, a, m); + sp_256_norm_8(r); + sp_256_rshift1_8(r, r, carry); } /* Add two Montgomery form numbers (r = a + b % m) */ -static void sp_256_mont_add_10(sp_digit* r, const sp_digit* a, const sp_digit* b, +static void sp_256_mont_add_8(sp_digit* r, const sp_digit* a, const sp_digit* b, const sp_digit* m) { - sp_256_add_10(r, a, b); - sp_256_norm_10(r); - if ((r[9] >> 22) > 0) { - sp_256_sub_10(r, r, m); - sp_256_norm_10(r); + int carry = sp_256_add_8(r, a, b); + sp_256_norm_8(r); + if (carry) { + sp_256_sub_8(r, r, m); + sp_256_norm_8(r); } } /* Subtract two Montgomery form numbers (r = a - b % m) */ -static void sp_256_mont_sub_10(sp_digit* r, const sp_digit* a, const sp_digit* b, +static void sp_256_mont_sub_8(sp_digit* r, const sp_digit* a, const sp_digit* b, const sp_digit* m) { - sp_256_sub_10(r, a, b); - sp_256_norm_10(r); - if (r[9] >> 22) { - sp_256_add_10(r, r, m); - sp_256_norm_10(r); - r[9] &= 0x03fffff; /* truncate to 22 bits */ + int borrow; + borrow = sp_256_sub_8(r, a, b); + sp_256_norm_8(r); + if (borrow) { + sp_256_add_8(r, r, m); + sp_256_norm_8(r); } } /* Double a Montgomery form number (r = a + a % m) */ -static void sp_256_mont_dbl_10(sp_digit* r, const sp_digit* a, const sp_digit* m) +static void sp_256_mont_dbl_8(sp_digit* r, const sp_digit* a, const sp_digit* m) { - sp_256_add_10(r, a, a); - sp_256_norm_10(r); - if ((r[9] >> 22) > 0) - sp_256_sub_10(r, r, m); - sp_256_norm_10(r); + int carry = sp_256_add_8(r, a, a); + sp_256_norm_8(r); + if (carry) + sp_256_sub_8(r, r, m); + sp_256_norm_8(r); } /* Triple a Montgomery form number (r = a + a + a % m) */ -static void sp_256_mont_tpl_10(sp_digit* r, const sp_digit* a, const sp_digit* m) +static void sp_256_mont_tpl_8(sp_digit* r, const sp_digit* a, const sp_digit* m) { - sp_256_add_10(r, a, a); - sp_256_norm_10(r); - if ((r[9] >> 22) > 0) { - sp_256_sub_10(r, r, m); - sp_256_norm_10(r); + int carry = sp_256_add_8(r, a, a); + sp_256_norm_8(r); + if (carry) { + sp_256_sub_8(r, r, m); + sp_256_norm_8(r); } - sp_256_add_10(r, r, a); - sp_256_norm_10(r); - if ((r[9] >> 22) > 0) { - sp_256_sub_10(r, r, m); - sp_256_norm_10(r); + carry = sp_256_add_8(r, r, a); + sp_256_norm_8(r); + if (carry) { + sp_256_sub_8(r, r, m); + sp_256_norm_8(r); } - r[9] &= 0x03fffff; /* truncate to 22 bits */ } /* Shift the result in the high 256 bits down to the bottom. */ -static void sp_256_mont_shift_10(sp_digit* r, const sp_digit* a) +static void sp_256_mont_shift_8(sp_digit* r, const sp_digit* a) { int i; - sp_digit n, s; - - s = a[10]; - n = a[9] >> 22; - for (i = 0; i < 9; i++) { - n += (s & 0x3ffffff) << 4; - r[i] = n & 0x3ffffff; - n >>= 26; - s = a[11 + i] + (s >> 26); + + for (i = 0; i < 8; i++) { + r[i] = a[i+8]; + r[i+8] = 0; } - n += s << 4; - r[9] = n; - memset(&r[10], 0, sizeof(*r) * 10); } /* Mul a by scalar b and add into r. (r += a * b) */ -static void sp_256_mul_add_10(sp_digit* r, const sp_digit* a, sp_digit b) +static int sp_256_mul_add_8(sp_digit* r, const sp_digit* a, sp_digit b) { - int64_t t = 0; + uint64_t t = 0; int i; - for (i = 0; i < 10; i++) { - t += ((int64_t)b * a[i]) + r[i]; - r[i] = t & 0x3ffffff; - t >>= 26; + for (i = 0; i < 8; i++) { + uint32_t t_hi; + uint64_t m = ((uint64_t)b * a[i]) + r[i]; + t += m; + t_hi = (t < m); + r[i] = (sp_digit)t; + t = (t >> 32) | ((uint64_t)t_hi << 32); } - r[10] += t; + r[8] += (sp_digit)t; + return (r[8] < (sp_digit)t); /* 1 if addition overflowed */ } /* Reduce the number back to 256 bits using Montgomery reduction. @@ -374,7 +431,7 @@ static void sp_256_mul_add_10(sp_digit* r, const sp_digit* a, sp_digit b) * m The single precision number representing the modulus. * mp The digit representing the negative inverse of m mod 2^n. */ -static void sp_256_mont_reduce_10(sp_digit* a /*, const sp_digit* m, sp_digit mp*/) +static void sp_256_mont_reduce_8(sp_digit* a/*, const sp_digit* m, sp_digit mp*/) { const sp_digit* m = p256_mod; sp_digit mp = p256_mp_mod; @@ -383,33 +440,144 @@ static void sp_256_mont_reduce_10(sp_digit* a /*, const sp_digit* m, sp_digit mp sp_digit mu; if (mp != 1) { - for (i = 0; i < 9; i++) { - mu = (a[i] * mp) & 0x3ffffff; - sp_256_mul_add_10(a+i, m, mu); - a[i+1] += a[i] >> 26; + int too_wide; + for (i = 0; i < 7; i++) { + mu = (sp_digit)(a[i] * mp); + if (sp_256_mul_add_8(a+i, m, mu)) + (a+i)[9]++; } - mu = (a[i] * mp) & 0x03fffff; - sp_256_mul_add_10(a+i, m, mu); - a[i+1] += a[i] >> 26; - a[i] &= 0x3ffffff; + mu = (sp_digit)(a[7] * mp); + too_wide = sp_256_mul_add_8(a+7, m, mu); + sp_256_mont_shift_8(a, a); + if (too_wide) + sp_256_sub_8(a, a, m); + sp_256_norm_8(a); } else { /* Same code for explicit mp == 1 (which is always the case for P256) */ - for (i = 0; i < 9; i++) { - mu = a[i] & 0x3ffffff; - sp_256_mul_add_10(a+i, m, mu); - a[i+1] += a[i] >> 26; + sp_digit word16th = 0; + for (i = 0; i < 8; i++) { + mu = a[i]; +//m = ffffffff 00000001 00000000 00000000 00000000 ffffffff ffffffff ffffffff + if (sp_256_mul_add_8(a+i, m, mu)) { + int j = i + 8; + inc_next_word: + if (++j > 15) { /* a[16] array has no more words? */ + word16th++; + continue; + } + if (++a[j] == 0) /* did this overflow too? */ + goto inc_next_word; + } } - mu = a[i] & 0x03fffff; - sp_256_mul_add_10(a+i, m, mu); - a[i+1] += a[i] >> 26; - a[i] &= 0x3ffffff; + sp_256_mont_shift_8(a, a); + if (word16th != 0) + sp_256_sub_8(a, a, m); + sp_256_norm_8(a); } - - sp_256_mont_shift_10(a, a); - if ((a[9] >> 22) > 0) - sp_256_sub_10(a, a, m); - sp_256_norm_10(a); } +#if 0 +//TODO: arm32 asm (also adapt for x86?) +static void sp_256_mont_reduce_8(sp_digit* a, sp_digit* m, sp_digit mp) +{ + sp_digit ca = 0; + + asm volatile ( + # i = 0 + mov r12, #0 # i = 0 + ldr r10, [%[a], #0] # r10 = a[0] + ldr r14, [%[a], #4] # r14 = a[1] +1: + # mu = a[i] * mp # + mul r8, %[mp], r10 # mu = a[i] * mp + # a[i+0] += m[0] * mu # + ldr r7, [%[m], #0] # a[i+0] += m[0] * mu + ldr r9, [%[a], #0] # + umull r6, r7, r8, r7 # r7:r6 = mu * m[0] + adds r10, r10, r6 # r5:r10 += r7:r6 + adc r5, r7, #0 # + # a[i+1] += m[1] * mu # + ldr r7, [%[m], #4] # a[i+1] += m[1] * mu + ldr r9, [%[a], #4] # + umull r6, r7, r8, r7 # r7:r6 = mu * m[1] + adds r10, r14, r6 # r4:r10 = r7:r14 + r7:r6 + adc r4, r7, #0 # + adds r10, r10, r5 # r4:r10 += r5 + adc r4, r4, #0 # + # a[i+2] += m[2] * mu # + ldr r7, [%[m], #8] # a[i+2] += m[2] * mu + ldr r14, [%[a], #8] # + umull r6, r7, r8, r7 # + adds r14, r14, r6 # + adc r5, r7, #0 # + adds r14, r14, r4 # + adc r5, r5, #0 # + # a[i+3] += m[3] * mu # + ldr r7, [%[m], #12] # a[i+3] += m[3] * mu + ldr r9, [%[a], #12] # + umull r6, r7, r8, r7 # + adds r9, r9, r6 # + adc r4, r7, #0 # + adds r9, r9, r5 # + str r9, [%[a], #12] # a[3] = r9 + adc r4, r4, #0 # + # a[i+4] += m[4] * mu # + ldr r7, [%[m], #16] # a[i+4] += m[4] * mu + ldr r9, [%[a], #16] # + umull r6, r7, r8, r7 # + adds r9, r9, r6 # + adc r5, r7, #0 # + adds r9, r9, r4 # + str r9, [%[a], #16] # a[4] = r9 + adc r5, r5, #0 # + # a[i+5] += m[5] * mu # + ldr r7, [%[m], #20] # a[i+5] += m[5] * mu + ldr r9, [%[a], #20] # + umull r6, r7, r8, r7 # + adds r9, r9, r6 # + adc r4, r7, #0 # + adds r9, r9, r5 # + str r9, [%[a], #20] # a[5] = r9 + adc r4, r4, #0 # + # a[i+6] += m[6] * mu # + ldr r7, [%[m], #24] # a[i+6] += m[6] * mu + ldr r9, [%[a], #24] # + umull r6, r7, r8, r7 # + adds r9, r9, r6 # + adc r5, r7, #0 # + adds r9, r9, r4 # + str r9, [%[a], #24] # a[6] = r9 + adc r5, r5, #0 # + # a[i+7] += m[7] * mu # + ldr r7, [%[m], #28] # a[i+7] += m[7] * mu + ldr r9, [%[a], #28] # + umull r6, r7, r8, r7 # + adds r5, r5, r6 # + adcs r7, r7, %[ca] # + mov %[ca], #0 # + adc %[ca], %[ca], %[ca] # ca = CF + adds r9, r9, r5 # + str r9, [%[a], #28] # a[7] = r9 + ldr r9, [%[a], #32] # r9 = a[8] + adcs r9, r9, r7 # + str r9, [%[a], #32] # a[8] = r9 + adc %[ca], %[ca], #0 # ca += CF + # i += 1 # i++ + add %[a], %[a], #4 # a++ + add r12, r12, #4 # i += 4 + cmp r12, #32 # if (i < 32) + blt 1b # goto 1 + + str r10, [%[a], #0] # a[0] = r10 + str r14, [%[a], #4] # a[1] = r14 + : [ca] "+r" (ca), [a] "+r" (a) + : [m] "r" (m), [mp] "r" (mp) + : "memory", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r14", "r12" + ); + + if (ca) + a -= m; +} +#endif /* Multiply two Montogmery form numbers mod the modulus (prime). * (r = a * b mod m) @@ -420,14 +588,13 @@ static void sp_256_mont_reduce_10(sp_digit* a /*, const sp_digit* m, sp_digit mp * m Modulus (prime). * mp Montogmery mulitplier. */ -static void sp_256_mont_mul_10(sp_digit* r, const sp_digit* a, const sp_digit* b +static void sp_256_mont_mul_8(sp_digit* r, const sp_digit* a, const sp_digit* b /*, const sp_digit* m, sp_digit mp*/) { //const sp_digit* m = p256_mod; //sp_digit mp = p256_mp_mod; - - sp_256_mul_10(r, a, b); - sp_256_mont_reduce_10(r /*, m, mp*/); + sp_256_mul_8(r, a, b); + sp_256_mont_reduce_8(r /*, m, mp*/); } /* Square the Montgomery form number. (r = a * a mod m) @@ -437,13 +604,12 @@ static void sp_256_mont_mul_10(sp_digit* r, const sp_digit* a, const sp_digit* b * m Modulus (prime). * mp Montogmery mulitplier. */ -static void sp_256_mont_sqr_10(sp_digit* r, const sp_digit* a +static void sp_256_mont_sqr_8(sp_digit* r, const sp_digit* a /*, const sp_digit* m, sp_digit mp*/) { //const sp_digit* m = p256_mod; //sp_digit mp = p256_mp_mod; - - sp_256_mont_mul_10(r, a, a /*, m, mp*/); + sp_256_mont_mul_8(r, a, a /*, m, mp*/); } /* Invert the number, in Montgomery form, modulo the modulus (prime) of the @@ -464,19 +630,19 @@ static const uint32_t p256_mod_2[8] = { //543210987654321098765432109876543210987654321098765432109876543210...09876543210...09876543210 //111111111111111111111111111111110000000000000000000000000000000100...00000111111...11111111101 #endif -static void sp_256_mont_inv_10(sp_digit* r, sp_digit* a) +static void sp_256_mont_inv_8(sp_digit* r, sp_digit* a) { - sp_digit t[2*10]; //can be just [10]? + sp_digit t[2*8]; //can be just [8]? int i; - memcpy(t, a, sizeof(sp_digit) * 10); + memcpy(t, a, sizeof(sp_digit) * 8); for (i = 254; i >= 0; i--) { - sp_256_mont_sqr_10(t, t /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t, t /*, p256_mod, p256_mp_mod*/); /*if (p256_mod_2[i / 32] & ((sp_digit)1 << (i % 32)))*/ if (i >= 224 || i == 192 || (i <= 95 && i != 1)) - sp_256_mont_mul_10(t, t, a /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t, t, a /*, p256_mod, p256_mp_mod*/); } - memcpy(r, t, sizeof(sp_digit) * 10); + memcpy(r, t, sizeof(sp_digit) * 8); } /* Multiply a number by Montogmery normalizer mod modulus (prime). @@ -484,93 +650,29 @@ static void sp_256_mont_inv_10(sp_digit* r, sp_digit* a) * r The resulting Montgomery form number. * a The number to convert. */ -static void sp_256_mod_mul_norm_10(sp_digit* r, const sp_digit* a) +static void sp_256_mod_mul_norm_8(sp_digit* r, const sp_digit* a) { int64_t t[8]; - int64_t o; - uint32_t a32; + int32_t o; +#define A(n) ((uint64_t)a[n]) /* 1 1 0 -1 -1 -1 -1 0 */ + t[0] = 0 + A(0) + A(1) - A(3) - A(4) - A(5) - A(6); /* 0 1 1 0 -1 -1 -1 -1 */ + t[1] = 0 + A(1) + A(2) - A(4) - A(5) - A(6) - A(7); /* 0 0 1 1 0 -1 -1 -1 */ + t[2] = 0 + A(2) + A(3) - A(5) - A(6) - A(7); /* -1 -1 0 2 2 1 0 -1 */ + t[3] = 0 - A(0) - A(1) + 2 * A(3) + 2 * A(4) + A(5) - A(7); /* 0 -1 -1 0 2 2 1 0 */ + t[4] = 0 - A(1) - A(2) + 2 * A(4) + 2 * A(5) + A(6); /* 0 0 -1 -1 0 2 2 1 */ + t[5] = 0 - A(2) - A(3) + 2 * A(5) + 2 * A(6) + A(7); /* -1 -1 0 0 0 1 3 2 */ + t[6] = 0 - A(0) - A(1) + A(5) + 3 * A(6) + 2 * A(7); /* 1 0 -1 -1 -1 -1 0 3 */ - // t[] should be calculated from "a" (converted from 26-bit to 32-bit vector a32[8]) - // according to the above matrix: - //t[0] = 0 + a32[0] + a32[1] - a32[3] - a32[4] - a32[5] - a32[6] ; - //t[1] = 0 + a32[1] + a32[2] - a32[4] - a32[5] - a32[6] - a32[7] ; - //t[2] = 0 + a32[2] + a32[3] - a32[5] - a32[6] - a32[7] ; - //t[3] = 0 - a32[0] - a32[1] + 2*a32[3] + 2*a32[4] + a32[5] - a32[7] ; - //t[4] = 0 - a32[1] - a32[2] + 2*a32[4] + 2*a32[5] + a32[6] ; - //t[5] = 0 - a32[2] - a32[3] + 2*a32[5] + 2*a32[6] + a32[7] ; - //t[6] = 0 - a32[0] - a32[1] + a32[5] + 3*a32[6] + 2*a32[7]; - //t[7] = 0 + a32[0] - a32[2] - a32[3] - a32[4] - a32[5] + 3*a32[7]; - // We can do it "piecemeal" after each a32[i] is known, no need to store entire a32[8] vector: - -#define A32 (int64_t)a32 - a32 = a[0] | (a[1] << 26); - t[0] = 0 + A32; - t[3] = 0 - A32; - t[6] = 0 - A32; - t[7] = 0 + A32; - - a32 = (a[1] >> 6) | (a[2] << 20); - t[0] += A32 ; - t[1] = 0 + A32; - t[3] -= A32 ; - t[4] = 0 - A32; - t[6] -= A32 ; - - a32 = (a[2] >> 12) | (a[3] << 14); - t[1] += A32 ; - t[2] = 0 + A32; - t[4] -= A32 ; - t[5] = 0 - A32; - t[7] -= A32 ; - - a32 = (a[3] >> 18) | (a[4] << 8); - t[0] -= A32 ; - t[2] += A32 ; - t[3] += 2*A32; - t[5] -= A32 ; - t[7] -= A32 ; - - a32 = (a[4] >> 24) | (a[5] << 2) | (a[6] << 28); - t[0] -= A32 ; - t[1] -= A32 ; - t[3] += 2*A32; - t[4] += 2*A32; - t[7] -= A32 ; - - a32 = (a[6] >> 4) | (a[7] << 22); - t[0] -= A32 ; - t[1] -= A32 ; - t[2] -= A32 ; - t[3] += A32 ; - t[4] += 2*A32; - t[5] += 2*A32; - t[6] += A32 ; - t[7] -= A32 ; - - a32 = (a[7] >> 10) | (a[8] << 16); - t[0] -= A32 ; - t[1] -= A32 ; - t[2] -= A32 ; - t[4] += A32 ; - t[5] += 2*A32; - t[6] += 3*A32; - - a32 = (a[8] >> 16) | (a[9] << 10); - t[1] -= A32 ; - t[2] -= A32 ; - t[3] -= A32 ; - t[5] += A32 ; - t[6] += 2*A32; - t[7] += 3*A32; -#undef A32 + t[7] = 0 + A(0) - A(2) - A(3) - A(4) - A(5) + 3 * A(7); +#undef A t[1] += t[0] >> 32; t[0] &= 0xffffffff; t[2] += t[1] >> 32; t[1] &= 0xffffffff; @@ -579,29 +681,27 @@ static void sp_256_mod_mul_norm_10(sp_digit* r, const sp_digit* a) t[5] += t[4] >> 32; t[4] &= 0xffffffff; t[6] += t[5] >> 32; t[5] &= 0xffffffff; t[7] += t[6] >> 32; t[6] &= 0xffffffff; - o = t[7] >> 32; t[7] &= 0xffffffff; + o = t[7] >> 32; //t[7] &= 0xffffffff; t[0] += o; t[3] -= o; t[6] -= o; t[7] += o; - t[1] += t[0] >> 32; //t[0] &= 0xffffffff; - t[2] += t[1] >> 32; //t[1] &= 0xffffffff; - t[3] += t[2] >> 32; //t[2] &= 0xffffffff; - t[4] += t[3] >> 32; //t[3] &= 0xffffffff; - t[5] += t[4] >> 32; //t[4] &= 0xffffffff; - t[6] += t[5] >> 32; //t[5] &= 0xffffffff; - t[7] += t[6] >> 32; //t[6] &= 0xffffffff; - (uint32_t)t[i] casts below accomplish masking - - r[0] = 0x3ffffff & ((sp_digit)((uint32_t)t[0])); - r[1] = 0x3ffffff & ((sp_digit)((uint32_t)t[0] >> 26) | ((sp_digit)t[1] << 6)); - r[2] = 0x3ffffff & ((sp_digit)((uint32_t)t[1] >> 20) | ((sp_digit)t[2] << 12)); - r[3] = 0x3ffffff & ((sp_digit)((uint32_t)t[2] >> 14) | ((sp_digit)t[3] << 18)); - r[4] = 0x3ffffff & ((sp_digit)((uint32_t)t[3] >> 8) | ((sp_digit)t[4] << 24)); - r[5] = 0x3ffffff & ((sp_digit)((uint32_t)t[4] >> 2)); - r[6] = 0x3ffffff & ((sp_digit)((uint32_t)t[4] >> 28) | ((sp_digit)t[5] << 4)); - r[7] = 0x3ffffff & ((sp_digit)((uint32_t)t[5] >> 22) | ((sp_digit)t[6] << 10)); - r[8] = 0x3ffffff & ((sp_digit)((uint32_t)t[6] >> 16) | ((sp_digit)t[7] << 16)); - r[9] = ((sp_digit)((uint32_t)t[7] >> 10)); + r[0] = (sp_digit)t[0]; + t[1] += t[0] >> 32; + r[1] = (sp_digit)t[1]; + t[2] += t[1] >> 32; + r[2] = (sp_digit)t[2]; + t[3] += t[2] >> 32; + r[3] = (sp_digit)t[3]; + t[4] += t[3] >> 32; + r[4] = (sp_digit)t[4]; + t[5] += t[4] >> 32; + r[5] = (sp_digit)t[5]; + t[6] += t[5] >> 32; + r[6] = (sp_digit)t[6]; +// t[7] += t[6] >> 32; +// r[7] = (sp_digit)t[7]; + r[7] = (sp_digit)t[7] + (sp_digit)(t[6] >> 32); } /* Map the Montgomery form projective co-ordinate point to an affine point. @@ -609,33 +709,33 @@ static void sp_256_mod_mul_norm_10(sp_digit* r, const sp_digit* a) * r Resulting affine co-ordinate point. * p Montgomery form projective co-ordinate point. */ -static void sp_256_map_10(sp_point* r, sp_point* p) +static void sp_256_map_8(sp_point* r, sp_point* p) { - sp_digit t1[2*10]; - sp_digit t2[2*10]; + sp_digit t1[2*8]; + sp_digit t2[2*8]; - sp_256_mont_inv_10(t1, p->z); + sp_256_mont_inv_8(t1, p->z); - sp_256_mont_sqr_10(t2, t1 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t1, t2, t1 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t2, t1 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t1, t2, t1 /*, p256_mod, p256_mp_mod*/); /* x /= z^2 */ - sp_256_mont_mul_10(r->x, p->x, t2 /*, p256_mod, p256_mp_mod*/); - memset(r->x + 10, 0, sizeof(r->x) / 2); - sp_256_mont_reduce_10(r->x /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->x, p->x, t2 /*, p256_mod, p256_mp_mod*/); + memset(r->x + 8, 0, sizeof(r->x) / 2); + sp_256_mont_reduce_8(r->x /*, p256_mod, p256_mp_mod*/); /* Reduce x to less than modulus */ - if (sp_256_cmp_10(r->x, p256_mod) >= 0) - sp_256_sub_10(r->x, r->x, p256_mod); - sp_256_norm_10(r->x); + if (sp_256_cmp_8(r->x, p256_mod) >= 0) + sp_256_sub_8(r->x, r->x, p256_mod); + sp_256_norm_8(r->x); /* y /= z^3 */ - sp_256_mont_mul_10(r->y, p->y, t1 /*, p256_mod, p256_mp_mod*/); - memset(r->y + 10, 0, sizeof(r->y) / 2); - sp_256_mont_reduce_10(r->y /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->y, p->y, t1 /*, p256_mod, p256_mp_mod*/); + memset(r->y + 8, 0, sizeof(r->y) / 2); + sp_256_mont_reduce_8(r->y /*, p256_mod, p256_mp_mod*/); /* Reduce y to less than modulus */ - if (sp_256_cmp_10(r->y, p256_mod) >= 0) - sp_256_sub_10(r->y, r->y, p256_mod); - sp_256_norm_10(r->y); + if (sp_256_cmp_8(r->y, p256_mod) >= 0) + sp_256_sub_8(r->y, r->y, p256_mod); + sp_256_norm_8(r->y); memset(r->z, 0, sizeof(r->z)); r->z[0] = 1; @@ -646,16 +746,16 @@ static void sp_256_map_10(sp_point* r, sp_point* p) * r Result of doubling point. * p Point to double. */ -static void sp_256_proj_point_dbl_10(sp_point* r, sp_point* p) +static void sp_256_proj_point_dbl_8(sp_point* r, sp_point* p) { - sp_digit t1[2*10]; - sp_digit t2[2*10]; + sp_digit t1[2*8]; + sp_digit t2[2*8]; /* Put point to double into result */ if (r != p) *r = *p; /* struct copy */ - if (r->infinity) /* If infinity, don't double */ + if (r->infinity) return; if (SP_DEBUG) { @@ -666,41 +766,42 @@ static void sp_256_proj_point_dbl_10(sp_point* r, sp_point* p) } /* T1 = Z * Z */ - sp_256_mont_sqr_10(t1, r->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t1, r->z /*, p256_mod, p256_mp_mod*/); /* Z = Y * Z */ - sp_256_mont_mul_10(r->z, r->y, r->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->z, r->y, r->z /*, p256_mod, p256_mp_mod*/); /* Z = 2Z */ - sp_256_mont_dbl_10(r->z, r->z, p256_mod); + sp_256_mont_dbl_8(r->z, r->z, p256_mod); /* T2 = X - T1 */ - sp_256_mont_sub_10(t2, r->x, t1, p256_mod); + sp_256_mont_sub_8(t2, r->x, t1, p256_mod); /* T1 = X + T1 */ - sp_256_mont_add_10(t1, r->x, t1, p256_mod); + sp_256_mont_add_8(t1, r->x, t1, p256_mod); /* T2 = T1 * T2 */ - sp_256_mont_mul_10(t2, t1, t2 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t2, t1, t2 /*, p256_mod, p256_mp_mod*/); /* T1 = 3T2 */ - sp_256_mont_tpl_10(t1, t2, p256_mod); + sp_256_mont_tpl_8(t1, t2, p256_mod); /* Y = 2Y */ - sp_256_mont_dbl_10(r->y, r->y, p256_mod); + sp_256_mont_dbl_8(r->y, r->y, p256_mod); /* Y = Y * Y */ - sp_256_mont_sqr_10(r->y, r->y /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(r->y, r->y /*, p256_mod, p256_mp_mod*/); /* T2 = Y * Y */ - sp_256_mont_sqr_10(t2, r->y /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t2, r->y /*, p256_mod, p256_mp_mod*/); /* T2 = T2/2 */ - sp_256_div2_10(t2, t2, p256_mod); + sp_256_div2_8(t2, t2, p256_mod); /* Y = Y * X */ - sp_256_mont_mul_10(r->y, r->y, r->x /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->y, r->y, r->x /*, p256_mod, p256_mp_mod*/); /* X = T1 * T1 */ - sp_256_mont_mul_10(r->x, t1, t1 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->x, t1, t1 /*, p256_mod, p256_mp_mod*/); /* X = X - Y */ - sp_256_mont_sub_10(r->x, r->x, r->y, p256_mod); + sp_256_mont_sub_8(r->x, r->x, r->y, p256_mod); /* X = X - Y */ - sp_256_mont_sub_10(r->x, r->x, r->y, p256_mod); + sp_256_mont_sub_8(r->x, r->x, r->y, p256_mod); /* Y = Y - X */ - sp_256_mont_sub_10(r->y, r->y, r->x, p256_mod); + sp_256_mont_sub_8(r->y, r->y, r->x, p256_mod); /* Y = Y * T1 */ - sp_256_mont_mul_10(r->y, r->y, t1 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r->y, r->y, t1 /*, p256_mod, p256_mp_mod*/); /* Y = Y - T2 */ - sp_256_mont_sub_10(r->y, r->y, t2, p256_mod); + sp_256_mont_sub_8(r->y, r->y, t2, p256_mod); + dump_512("y2 %s\n", r->y); } /* Add two Montgomery form projective points. @@ -709,13 +810,13 @@ static void sp_256_proj_point_dbl_10(sp_point* r, sp_point* p) * p Frist point to add. * q Second point to add. */ -static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q) +static void sp_256_proj_point_add_8(sp_point* r, sp_point* p, sp_point* q) { - sp_digit t1[2*10]; - sp_digit t2[2*10]; - sp_digit t3[2*10]; - sp_digit t4[2*10]; - sp_digit t5[2*10]; + sp_digit t1[2*8]; + sp_digit t2[2*8]; + sp_digit t3[2*8]; + sp_digit t4[2*8]; + sp_digit t5[2*8]; /* Ensure only the first point is the same as the result. */ if (q == r) { @@ -725,13 +826,13 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q) } /* Check double */ - sp_256_sub_10(t1, p256_mod, q->y); - sp_256_norm_10(t1); - if (sp_256_cmp_equal_10(p->x, q->x) - && sp_256_cmp_equal_10(p->z, q->z) - && (sp_256_cmp_equal_10(p->y, q->y) || sp_256_cmp_equal_10(p->y, t1)) + sp_256_sub_8(t1, p256_mod, q->y); + sp_256_norm_8(t1); + if (sp_256_cmp_equal_8(p->x, q->x) + && sp_256_cmp_equal_8(p->z, q->z) + && (sp_256_cmp_equal_8(p->y, q->y) || sp_256_cmp_equal_8(p->y, t1)) ) { - sp_256_proj_point_dbl_10(r, p); + sp_256_proj_point_dbl_8(r, p); } else { sp_point tp; @@ -746,37 +847,37 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q) *r = p->infinity ? *q : *p; /* struct copy */ /* U1 = X1*Z2^2 */ - sp_256_mont_sqr_10(t1, q->z /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t3, t1, q->z /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t1, t1, v->x /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t1, q->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t3, t1, q->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t1, t1, v->x /*, p256_mod, p256_mp_mod*/); /* U2 = X2*Z1^2 */ - sp_256_mont_sqr_10(t2, v->z /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t4, t2, v->z /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t2, t2, q->x /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t2, v->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t4, t2, v->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t2, t2, q->x /*, p256_mod, p256_mp_mod*/); /* S1 = Y1*Z2^3 */ - sp_256_mont_mul_10(t3, t3, v->y /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t3, t3, v->y /*, p256_mod, p256_mp_mod*/); /* S2 = Y2*Z1^3 */ - sp_256_mont_mul_10(t4, t4, q->y /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t4, t4, q->y /*, p256_mod, p256_mp_mod*/); /* H = U2 - U1 */ - sp_256_mont_sub_10(t2, t2, t1, p256_mod); + sp_256_mont_sub_8(t2, t2, t1, p256_mod); /* R = S2 - S1 */ - sp_256_mont_sub_10(t4, t4, t3, p256_mod); + sp_256_mont_sub_8(t4, t4, t3, p256_mod); /* Z3 = H*Z1*Z2 */ - sp_256_mont_mul_10(v->z, v->z, q->z /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(v->z, v->z, t2 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(v->z, v->z, q->z /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(v->z, v->z, t2 /*, p256_mod, p256_mp_mod*/); /* X3 = R^2 - H^3 - 2*U1*H^2 */ - sp_256_mont_sqr_10(v->x, t4 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_sqr_10(t5, t2 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(v->y, t1, t5 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t5, t5, t2 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_sub_10(v->x, v->x, t5, p256_mod); - sp_256_mont_dbl_10(t1, v->y, p256_mod); - sp_256_mont_sub_10(v->x, v->x, t1, p256_mod); + sp_256_mont_sqr_8(v->x, t4 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(t5, t2 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(v->y, t1, t5 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t5, t5, t2 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sub_8(v->x, v->x, t5, p256_mod); + sp_256_mont_dbl_8(t1, v->y, p256_mod); + sp_256_mont_sub_8(v->x, v->x, t1, p256_mod); /* Y3 = R*(U1*H^2 - X3) - S1*H^3 */ - sp_256_mont_sub_10(v->y, v->y, v->x, p256_mod); - sp_256_mont_mul_10(v->y, v->y, t4 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_mul_10(t5, t5, t3 /*, p256_mod, p256_mp_mod*/); - sp_256_mont_sub_10(v->y, v->y, t5, p256_mod); + sp_256_mont_sub_8(v->y, v->y, v->x, p256_mod); + sp_256_mont_mul_8(v->y, v->y, t4 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(t5, t5, t3 /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sub_8(v->y, v->y, t5, p256_mod); } } @@ -788,12 +889,11 @@ static void sp_256_proj_point_add_10(sp_point* r, sp_point* p, sp_point* q) * k Scalar to multiply by. * map Indicates whether to convert result to affine. */ -static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* k /*, int map*/) +static void sp_256_ecc_mulmod_8(sp_point* r, const sp_point* g, const sp_digit* k /*, int map*/) { enum { map = 1 }; /* we always convert result to affine coordinates */ sp_point t[3]; - sp_digit n; - int i; + sp_digit n = n; /* for compiler */ int c, y; memset(t, 0, sizeof(t)); @@ -801,36 +901,44 @@ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* /* t[0] = {0, 0, 1} * norm */ t[0].infinity = 1; /* t[1] = {g->x, g->y, g->z} * norm */ - sp_256_mod_mul_norm_10(t[1].x, g->x); - sp_256_mod_mul_norm_10(t[1].y, g->y); - sp_256_mod_mul_norm_10(t[1].z, g->z); - dump_512("t[1].x %s\n", t[1].x); - dump_512("t[1].y %s\n", t[1].y); - dump_512("t[1].z %s\n", t[1].z); - - i = 9; - c = 22; - n = k[i--] << (26 - c); - for (; ; c--) { - if (c == 0) { - if (i == -1) - break; + sp_256_mod_mul_norm_8(t[1].x, g->x); + sp_256_mod_mul_norm_8(t[1].y, g->y); + sp_256_mod_mul_norm_8(t[1].z, g->z); - n = k[i--]; - c = 26; + /* For every bit, starting from most significant... */ + k += 7; + c = 256; + for (;;) { + if ((c & 0x1f) == 0) { + if (c == 0) + break; + n = *k--; } - y = (n >> 25) & 1; - n <<= 1; - - sp_256_proj_point_add_10(&t[y^1], &t[0], &t[1]); + y = (n >> 31); + dbg("y:%d t[%d] = t[0]+t[1]\n", y, y^1); + sp_256_proj_point_add_8(&t[y^1], &t[0], &t[1]); + dump_512("t[0].x %s\n", t[0].x); + dump_512("t[0].y %s\n", t[0].y); + dump_512("t[0].z %s\n", t[0].z); + dump_512("t[1].x %s\n", t[1].x); + dump_512("t[1].y %s\n", t[1].y); + dump_512("t[1].z %s\n", t[1].z); + dbg("t[2] = t[%d]\n", y); memcpy(&t[2], &t[y], sizeof(sp_point)); - sp_256_proj_point_dbl_10(&t[2], &t[2]); + dbg("t[2] *= 2\n"); + sp_256_proj_point_dbl_8(&t[2], &t[2]); + dump_512("t[2].x %s\n", t[2].x); + dump_512("t[2].y %s\n", t[2].y); + dump_512("t[2].z %s\n", t[2].z); memcpy(&t[y], &t[2], sizeof(sp_point)); + + n <<= 1; + c--; } if (map) - sp_256_map_10(r, &t[0]); + sp_256_map_8(r, &t[0]); else memcpy(r, &t[0], sizeof(sp_point)); @@ -844,7 +952,7 @@ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit* * k Scalar to multiply by. * map Indicates whether to convert result to affine. */ -static void sp_256_ecc_mulmod_base_10(sp_point* r, sp_digit* k /*, int map*/) +static void sp_256_ecc_mulmod_base_8(sp_point* r, sp_digit* k /*, int map*/) { /* Since this function is called only once, save space: * don't have "static const sp_point p256_base = {...}", @@ -861,7 +969,7 @@ static void sp_256_ecc_mulmod_base_10(sp_point* r, sp_digit* k /*, int map*/) sp_256_point_from_bin2x32(&p256_base, p256_base_bin); - sp_256_ecc_mulmod_10(r, &p256_base, k /*, map*/); + sp_256_ecc_mulmod_8(r, &p256_base, k /*, map*/); } /* Multiply the point by the scalar and serialize the X ordinate. @@ -871,7 +979,7 @@ static void sp_256_ecc_mulmod_base_10(sp_point* r, sp_digit* k /*, int map*/) * pub2x32 Point to multiply. * out32 Buffer to hold X ordinate. */ -static void sp_ecc_secret_gen_256(const sp_digit priv[10], const uint8_t *pub2x32, uint8_t* out32) +static void sp_ecc_secret_gen_256(const sp_digit priv[8], const uint8_t *pub2x32, uint8_t* out32) { sp_point point[1]; @@ -885,66 +993,48 @@ static void sp_ecc_secret_gen_256(const sp_digit priv[10], const uint8_t *pub2x3 dump_512("point->x %s\n", point->x); dump_512("point->y %s\n", point->y); - sp_256_ecc_mulmod_10(point, point, priv); + sp_256_ecc_mulmod_8(point, point, priv); - sp_256_to_bin_10(point->x, out32); + sp_256_to_bin_8(point->x, out32); dump_hex("out32: %s\n", out32, 32); } -/* Generates a scalar that is in the range 1..order-1. */ -#define SIMPLIFY 1 -/* Add 1 to a. (a = a + 1) */ -static void sp_256_add_one_10(sp_digit* a) -{ - a[0]++; - sp_256_norm_10(a); -} -static void sp_256_ecc_gen_k_10(sp_digit k[10]) +/* Generates a random scalar in [1..order-1] range. */ +static void sp_256_ecc_gen_k_8(sp_digit k[8]) { -#if !SIMPLIFY - /* The order of the curve P256 minus 2. */ - static const sp_digit p256_order2[10] = { - 0x063254f,0x272b0bf,0x1e84f3b,0x2b69c5e,0x3bce6fa, - 0x3ffffff,0x3ffffff,0x00003ff,0x3ff0000,0x03fffff, - }; -#endif - uint8_t buf[32]; - - for (;;) { - tls_get_random(buf, sizeof(buf)); + /* Since 32-bit words are "dense", no need to use + * sp_256_from_bin_8(k, buf) to convert random stream + * to sp_digit array - just store random bits there directly. + */ + tls_get_random(k, 8 * sizeof(k[0])); #if FIXED_SECRET - memset(buf, 0x77, sizeof(buf)); + memset(k, 0x77, 8 * sizeof(k[0])); #endif - sp_256_from_bin_10(k, buf); -#if !SIMPLIFY - if (sp_256_cmp_10(k, p256_order2) < 0) - break; -#else - /* non-loopy version (and not needing p256_order2[]): - * if most-significant word seems that k can be larger - * than p256_order2, fix it up: - */ - if (k[9] >= 0x03fffff) - k[9] = 0x03ffffe; - break; -#endif - } - sp_256_add_one_10(k); -#undef SIMPLIFY + +// If scalar is too large, try again (pseudo-code) +// if (k >= 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551 - 1) // order of P256 +// goto pick_another_random; +// k++; // ensure non-zero + /* Simpler alternative, at the cost of not choosing some valid + * random values, and slightly non-uniform distribution */ + if (k[0] == 0) + k[0] = 1; + if (k[7] >= 0xffffffff) + k[7] = 0xfffffffe; } /* Makes a random EC key pair. */ -static void sp_ecc_make_key_256(sp_digit privkey[10], uint8_t *pubkey) +static void sp_ecc_make_key_256(sp_digit privkey[8], uint8_t *pubkey) { sp_point point[1]; - sp_256_ecc_gen_k_10(privkey); + sp_256_ecc_gen_k_8(privkey); dump_256("privkey %s\n", privkey); - sp_256_ecc_mulmod_base_10(point, privkey); + sp_256_ecc_mulmod_base_8(point, privkey); dump_512("point->x %s\n", point->x); dump_512("point->y %s\n", point->y); - sp_256_to_bin_10(point->x, pubkey); - sp_256_to_bin_10(point->y, pubkey + 32); + sp_256_to_bin_8(point->x, pubkey); + sp_256_to_bin_8(point->y, pubkey + 32); memset(point, 0, sizeof(point)); //paranoia } @@ -953,8 +1043,9 @@ void FAST_FUNC curve_P256_compute_pubkey_and_premaster( uint8_t *pubkey2x32, uint8_t *premaster32, const uint8_t *peerkey2x32) { - sp_digit privkey[10]; + sp_digit privkey[8]; + dump_hex("peerkey2x32: %s\n", peerkey2x32, 64); sp_ecc_make_key_256(privkey, pubkey2x32); dump_hex("pubkey: %s\n", pubkey2x32, 32); dump_hex(" %s\n", pubkey2x32 + 32, 32); |