# Automatically generated rules. Use 'mkrules.sh' to modify/regenerate.
-OBJ = $(OBJDIR)$Pccopy$O $(OBJDIR)$Pdec16be$O $(OBJDIR)$Pdec16le$O $(OBJDIR)$Pdec32be$O $(OBJDIR)$Pdec32le$O $(OBJDIR)$Pdec64be$O $(OBJDIR)$Pdec64le$O $(OBJDIR)$Penc16be$O $(OBJDIR)$Penc16le$O $(OBJDIR)$Penc32be$O $(OBJDIR)$Penc32le$O $(OBJDIR)$Penc64be$O $(OBJDIR)$Penc64le$O $(OBJDIR)$Ppemdec$O $(OBJDIR)$Pec_all_m15$O $(OBJDIR)$Pec_all_m31$O $(OBJDIR)$Pec_c25519_i15$O $(OBJDIR)$Pec_c25519_i31$O $(OBJDIR)$Pec_c25519_m15$O $(OBJDIR)$Pec_c25519_m31$O $(OBJDIR)$Pec_curve25519$O $(OBJDIR)$Pec_p256_m15$O $(OBJDIR)$Pec_p256_m31$O $(OBJDIR)$Pec_prime_i15$O $(OBJDIR)$Pec_prime_i31$O $(OBJDIR)$Pec_secp256r1$O $(OBJDIR)$Pec_secp384r1$O $(OBJDIR)$Pec_secp521r1$O $(OBJDIR)$Pecdsa_atr$O $(OBJDIR)$Pecdsa_i15_bits$O $(OBJDIR)$Pecdsa_i15_sign_asn1$O $(OBJDIR)$Pecdsa_i15_sign_raw$O $(OBJDIR)$Pecdsa_i15_vrfy_asn1$O $(OBJDIR)$Pecdsa_i15_vrfy_raw$O $(OBJDIR)$Pecdsa_i31_bits$O $(OBJDIR)$Pecdsa_i31_sign_asn1$O $(OBJDIR)$Pecdsa_i31_sign_raw$O $(OBJDIR)$Pecdsa_i31_vrfy_asn1$O $(OBJDIR)$Pecdsa_i31_vrfy_raw$O $(OBJDIR)$Pecdsa_rta$O $(OBJDIR)$Pdig_oid$O $(OBJDIR)$Pdig_size$O $(OBJDIR)$Pghash_ctmul$O $(OBJDIR)$Pghash_ctmul32$O $(OBJDIR)$Pghash_ctmul64$O $(OBJDIR)$Pmd5$O $(OBJDIR)$Pmd5sha1$O $(OBJDIR)$Pmultihash$O $(OBJDIR)$Psha1$O $(OBJDIR)$Psha2big$O $(OBJDIR)$Psha2small$O $(OBJDIR)$Pi15_add$O $(OBJDIR)$Pi15_bitlen$O $(OBJDIR)$Pi15_decmod$O $(OBJDIR)$Pi15_decode$O $(OBJDIR)$Pi15_decred$O $(OBJDIR)$Pi15_encode$O $(OBJDIR)$Pi15_fmont$O $(OBJDIR)$Pi15_iszero$O $(OBJDIR)$Pi15_modpow$O $(OBJDIR)$Pi15_montmul$O $(OBJDIR)$Pi15_mulacc$O $(OBJDIR)$Pi15_muladd$O $(OBJDIR)$Pi15_ninv15$O $(OBJDIR)$Pi15_reduce$O $(OBJDIR)$Pi15_rshift$O $(OBJDIR)$Pi15_sub$O $(OBJDIR)$Pi15_tmont$O $(OBJDIR)$Pi31_add$O $(OBJDIR)$Pi31_bitlen$O $(OBJDIR)$Pi31_decmod$O $(OBJDIR)$Pi31_decode$O $(OBJDIR)$Pi31_decred$O $(OBJDIR)$Pi31_encode$O $(OBJDIR)$Pi31_fmont$O $(OBJDIR)$Pi31_iszero$O $(OBJDIR)$Pi31_modpow$O $(OBJDIR)$Pi31_montmul$O $(OBJDIR)$Pi31_mulacc$O $(OBJDIR)$Pi31_muladd$O $(OBJDIR)$Pi31_ninv31$O $(OBJDIR)$Pi31_reduce$O $(OBJDIR)$Pi31_rshift$O $(OBJDIR)$Pi31_sub$O $(OBJDIR)$Pi31_tmont$O $(OBJDIR)$Pi32_add$O $(OBJDIR)$Pi32_bitlen$O $(OBJDIR)$Pi32_decmod$O $(OBJDIR)$Pi32_decode$O $(OBJDIR)$Pi32_decred$O $(OBJDIR)$Pi32_div32$O $(OBJDIR)$Pi32_encode$O $(OBJDIR)$Pi32_fmont$O $(OBJDIR)$Pi32_iszero$O $(OBJDIR)$Pi32_modpow$O $(OBJDIR)$Pi32_montmul$O $(OBJDIR)$Pi32_mulacc$O $(OBJDIR)$Pi32_muladd$O $(OBJDIR)$Pi32_ninv32$O $(OBJDIR)$Pi32_reduce$O $(OBJDIR)$Pi32_sub$O $(OBJDIR)$Pi32_tmont$O $(OBJDIR)$Phmac$O $(OBJDIR)$Phmac_ct$O $(OBJDIR)$Phmac_drbg$O $(OBJDIR)$Prsa_i15_pkcs1_sign$O $(OBJDIR)$Prsa_i15_pkcs1_vrfy$O $(OBJDIR)$Prsa_i15_priv$O $(OBJDIR)$Prsa_i15_pub$O $(OBJDIR)$Prsa_i31_pkcs1_sign$O $(OBJDIR)$Prsa_i31_pkcs1_vrfy$O $(OBJDIR)$Prsa_i31_priv$O $(OBJDIR)$Prsa_i31_pub$O $(OBJDIR)$Prsa_i32_pkcs1_sign$O $(OBJDIR)$Prsa_i32_pkcs1_vrfy$O $(OBJDIR)$Prsa_i32_priv$O $(OBJDIR)$Prsa_i32_pub$O $(OBJDIR)$Prsa_pkcs1_sig_pad$O $(OBJDIR)$Prsa_pkcs1_sig_unpad$O $(OBJDIR)$Prsa_ssl_decrypt$O $(OBJDIR)$Pprf$O $(OBJDIR)$Pprf_md5sha1$O $(OBJDIR)$Pprf_sha256$O $(OBJDIR)$Pprf_sha384$O $(OBJDIR)$Pssl_ccert_single_ec$O $(OBJDIR)$Pssl_ccert_single_rsa$O $(OBJDIR)$Pssl_client$O $(OBJDIR)$Pssl_client_full$O $(OBJDIR)$Pssl_engine$O $(OBJDIR)$Pssl_hashes$O $(OBJDIR)$Pssl_hs_client$O $(OBJDIR)$Pssl_hs_server$O $(OBJDIR)$Pssl_io$O $(OBJDIR)$Pssl_lru$O $(OBJDIR)$Pssl_rec_cbc$O $(OBJDIR)$Pssl_rec_chapol$O $(OBJDIR)$Pssl_rec_gcm$O $(OBJDIR)$Pssl_scert_single_ec$O $(OBJDIR)$Pssl_scert_single_rsa$O $(OBJDIR)$Pssl_server$O $(OBJDIR)$Pssl_server_full_ec$O $(OBJDIR)$Pssl_server_full_rsa$O $(OBJDIR)$Pssl_server_mine2c$O $(OBJDIR)$Pssl_server_mine2g$O $(OBJDIR)$Pssl_server_minf2c$O $(OBJDIR)$Pssl_server_minf2g$O $(OBJDIR)$Pssl_server_minr2g$O $(OBJDIR)$Pssl_server_minu2g$O $(OBJDIR)$Pssl_server_minv2g$O $(OBJDIR)$Paes_big_cbcdec$O $(OBJDIR)$Paes_big_cbcenc$O $(OBJDIR)$Paes_big_ctr$O $(OBJDIR)$Paes_big_dec$O $(OBJDIR)$Paes_big_enc$O $(OBJDIR)$Paes_common$O $(OBJDIR)$Paes_ct$O $(OBJDIR)$Paes_ct64$O $(OBJDIR)$Paes_ct64_cbcdec$O $(OBJDIR)$Paes_ct64_cbcenc$O $(OBJDIR)$Paes_ct64_ctr$O $(OBJDIR)$Paes_ct64_dec$O $(OBJDIR)$Paes_ct64_enc$O $(OBJDIR)$Paes_ct_cbcdec$O $(OBJDIR)$Paes_ct_cbcenc$O $(OBJDIR)$Paes_ct_ctr$O $(OBJDIR)$Paes_ct_dec$O $(OBJDIR)$Paes_ct_enc$O $(OBJDIR)$Paes_small_cbcdec$O $(OBJDIR)$Paes_small_cbcenc$O $(OBJDIR)$Paes_small_ctr$O $(OBJDIR)$Paes_small_dec$O $(OBJDIR)$Paes_small_enc$O $(OBJDIR)$Pchacha20_ct$O $(OBJDIR)$Pdes_ct$O $(OBJDIR)$Pdes_ct_cbcdec$O $(OBJDIR)$Pdes_ct_cbcenc$O $(OBJDIR)$Pdes_support$O $(OBJDIR)$Pdes_tab$O $(OBJDIR)$Pdes_tab_cbcdec$O $(OBJDIR)$Pdes_tab_cbcenc$O $(OBJDIR)$Ppoly1305_ctmul$O $(OBJDIR)$Ppoly1305_ctmul32$O $(OBJDIR)$Ppoly1305_i15$O $(OBJDIR)$Pskey_decoder$O $(OBJDIR)$Px509_decoder$O $(OBJDIR)$Px509_knownkey$O $(OBJDIR)$Px509_minimal$O $(OBJDIR)$Px509_minimal_full$O
+OBJ = $(OBJDIR)$Pccopy$O $(OBJDIR)$Pdec16be$O $(OBJDIR)$Pdec16le$O $(OBJDIR)$Pdec32be$O $(OBJDIR)$Pdec32le$O $(OBJDIR)$Pdec64be$O $(OBJDIR)$Pdec64le$O $(OBJDIR)$Penc16be$O $(OBJDIR)$Penc16le$O $(OBJDIR)$Penc32be$O $(OBJDIR)$Penc32le$O $(OBJDIR)$Penc64be$O $(OBJDIR)$Penc64le$O $(OBJDIR)$Ppemdec$O $(OBJDIR)$Pec_all_m15$O $(OBJDIR)$Pec_all_m31$O $(OBJDIR)$Pec_c25519_i15$O $(OBJDIR)$Pec_c25519_i31$O $(OBJDIR)$Pec_c25519_m15$O $(OBJDIR)$Pec_c25519_m31$O $(OBJDIR)$Pec_curve25519$O $(OBJDIR)$Pec_p256_m15$O $(OBJDIR)$Pec_p256_m31$O $(OBJDIR)$Pec_prime_i15$O $(OBJDIR)$Pec_prime_i31$O $(OBJDIR)$Pec_secp256r1$O $(OBJDIR)$Pec_secp384r1$O $(OBJDIR)$Pec_secp521r1$O $(OBJDIR)$Pecdsa_atr$O $(OBJDIR)$Pecdsa_i15_bits$O $(OBJDIR)$Pecdsa_i15_sign_asn1$O $(OBJDIR)$Pecdsa_i15_sign_raw$O $(OBJDIR)$Pecdsa_i15_vrfy_asn1$O $(OBJDIR)$Pecdsa_i15_vrfy_raw$O $(OBJDIR)$Pecdsa_i31_bits$O $(OBJDIR)$Pecdsa_i31_sign_asn1$O $(OBJDIR)$Pecdsa_i31_sign_raw$O $(OBJDIR)$Pecdsa_i31_vrfy_asn1$O $(OBJDIR)$Pecdsa_i31_vrfy_raw$O $(OBJDIR)$Pecdsa_rta$O $(OBJDIR)$Pdig_oid$O $(OBJDIR)$Pdig_size$O $(OBJDIR)$Pghash_ctmul$O $(OBJDIR)$Pghash_ctmul32$O $(OBJDIR)$Pghash_ctmul64$O $(OBJDIR)$Pmd5$O $(OBJDIR)$Pmd5sha1$O $(OBJDIR)$Pmultihash$O $(OBJDIR)$Psha1$O $(OBJDIR)$Psha2big$O $(OBJDIR)$Psha2small$O $(OBJDIR)$Pi15_add$O $(OBJDIR)$Pi15_bitlen$O $(OBJDIR)$Pi15_decmod$O $(OBJDIR)$Pi15_decode$O $(OBJDIR)$Pi15_decred$O $(OBJDIR)$Pi15_encode$O $(OBJDIR)$Pi15_fmont$O $(OBJDIR)$Pi15_iszero$O $(OBJDIR)$Pi15_modpow$O $(OBJDIR)$Pi15_modpow2$O $(OBJDIR)$Pi15_montmul$O $(OBJDIR)$Pi15_mulacc$O $(OBJDIR)$Pi15_muladd$O $(OBJDIR)$Pi15_ninv15$O $(OBJDIR)$Pi15_reduce$O $(OBJDIR)$Pi15_rshift$O $(OBJDIR)$Pi15_sub$O $(OBJDIR)$Pi15_tmont$O $(OBJDIR)$Pi31_add$O $(OBJDIR)$Pi31_bitlen$O $(OBJDIR)$Pi31_decmod$O $(OBJDIR)$Pi31_decode$O $(OBJDIR)$Pi31_decred$O $(OBJDIR)$Pi31_encode$O $(OBJDIR)$Pi31_fmont$O $(OBJDIR)$Pi31_iszero$O $(OBJDIR)$Pi31_modpow$O $(OBJDIR)$Pi31_montmul$O $(OBJDIR)$Pi31_mulacc$O $(OBJDIR)$Pi31_muladd$O $(OBJDIR)$Pi31_ninv31$O $(OBJDIR)$Pi31_reduce$O $(OBJDIR)$Pi31_rshift$O $(OBJDIR)$Pi31_sub$O $(OBJDIR)$Pi31_tmont$O $(OBJDIR)$Pi32_add$O $(OBJDIR)$Pi32_bitlen$O $(OBJDIR)$Pi32_decmod$O $(OBJDIR)$Pi32_decode$O $(OBJDIR)$Pi32_decred$O $(OBJDIR)$Pi32_div32$O $(OBJDIR)$Pi32_encode$O $(OBJDIR)$Pi32_fmont$O $(OBJDIR)$Pi32_iszero$O $(OBJDIR)$Pi32_modpow$O $(OBJDIR)$Pi32_montmul$O $(OBJDIR)$Pi32_mulacc$O $(OBJDIR)$Pi32_muladd$O $(OBJDIR)$Pi32_ninv32$O $(OBJDIR)$Pi32_reduce$O $(OBJDIR)$Pi32_sub$O $(OBJDIR)$Pi32_tmont$O $(OBJDIR)$Phmac$O $(OBJDIR)$Phmac_ct$O $(OBJDIR)$Phmac_drbg$O $(OBJDIR)$Prsa_i15_pkcs1_sign$O $(OBJDIR)$Prsa_i15_pkcs1_vrfy$O $(OBJDIR)$Prsa_i15_priv$O $(OBJDIR)$Prsa_i15_pub$O $(OBJDIR)$Prsa_i31_pkcs1_sign$O $(OBJDIR)$Prsa_i31_pkcs1_vrfy$O $(OBJDIR)$Prsa_i31_priv$O $(OBJDIR)$Prsa_i31_pub$O $(OBJDIR)$Prsa_i32_pkcs1_sign$O $(OBJDIR)$Prsa_i32_pkcs1_vrfy$O $(OBJDIR)$Prsa_i32_priv$O $(OBJDIR)$Prsa_i32_pub$O $(OBJDIR)$Prsa_pkcs1_sig_pad$O $(OBJDIR)$Prsa_pkcs1_sig_unpad$O $(OBJDIR)$Prsa_ssl_decrypt$O $(OBJDIR)$Pprf$O $(OBJDIR)$Pprf_md5sha1$O $(OBJDIR)$Pprf_sha256$O $(OBJDIR)$Pprf_sha384$O $(OBJDIR)$Pssl_ccert_single_ec$O $(OBJDIR)$Pssl_ccert_single_rsa$O $(OBJDIR)$Pssl_client$O $(OBJDIR)$Pssl_client_full$O $(OBJDIR)$Pssl_engine$O $(OBJDIR)$Pssl_hashes$O $(OBJDIR)$Pssl_hs_client$O $(OBJDIR)$Pssl_hs_server$O $(OBJDIR)$Pssl_io$O $(OBJDIR)$Pssl_lru$O $(OBJDIR)$Pssl_rec_cbc$O $(OBJDIR)$Pssl_rec_chapol$O $(OBJDIR)$Pssl_rec_gcm$O $(OBJDIR)$Pssl_scert_single_ec$O $(OBJDIR)$Pssl_scert_single_rsa$O $(OBJDIR)$Pssl_server$O $(OBJDIR)$Pssl_server_full_ec$O $(OBJDIR)$Pssl_server_full_rsa$O $(OBJDIR)$Pssl_server_mine2c$O $(OBJDIR)$Pssl_server_mine2g$O $(OBJDIR)$Pssl_server_minf2c$O $(OBJDIR)$Pssl_server_minf2g$O $(OBJDIR)$Pssl_server_minr2g$O $(OBJDIR)$Pssl_server_minu2g$O $(OBJDIR)$Pssl_server_minv2g$O $(OBJDIR)$Paes_big_cbcdec$O $(OBJDIR)$Paes_big_cbcenc$O $(OBJDIR)$Paes_big_ctr$O $(OBJDIR)$Paes_big_dec$O $(OBJDIR)$Paes_big_enc$O $(OBJDIR)$Paes_common$O $(OBJDIR)$Paes_ct$O $(OBJDIR)$Paes_ct64$O $(OBJDIR)$Paes_ct64_cbcdec$O $(OBJDIR)$Paes_ct64_cbcenc$O $(OBJDIR)$Paes_ct64_ctr$O $(OBJDIR)$Paes_ct64_dec$O $(OBJDIR)$Paes_ct64_enc$O $(OBJDIR)$Paes_ct_cbcdec$O $(OBJDIR)$Paes_ct_cbcenc$O $(OBJDIR)$Paes_ct_ctr$O $(OBJDIR)$Paes_ct_dec$O $(OBJDIR)$Paes_ct_enc$O $(OBJDIR)$Paes_small_cbcdec$O $(OBJDIR)$Paes_small_cbcenc$O $(OBJDIR)$Paes_small_ctr$O $(OBJDIR)$Paes_small_dec$O $(OBJDIR)$Paes_small_enc$O $(OBJDIR)$Pchacha20_ct$O $(OBJDIR)$Pdes_ct$O $(OBJDIR)$Pdes_ct_cbcdec$O $(OBJDIR)$Pdes_ct_cbcenc$O $(OBJDIR)$Pdes_support$O $(OBJDIR)$Pdes_tab$O $(OBJDIR)$Pdes_tab_cbcdec$O $(OBJDIR)$Pdes_tab_cbcenc$O $(OBJDIR)$Ppoly1305_ctmul$O $(OBJDIR)$Ppoly1305_ctmul32$O $(OBJDIR)$Ppoly1305_i15$O $(OBJDIR)$Pskey_decoder$O $(OBJDIR)$Px509_decoder$O $(OBJDIR)$Px509_knownkey$O $(OBJDIR)$Px509_minimal$O $(OBJDIR)$Px509_minimal_full$O
OBJBRSSL = $(OBJDIR)$Pbrssl$O $(OBJDIR)$Pcerts$O $(OBJDIR)$Pchain$O $(OBJDIR)$Pclient$O $(OBJDIR)$Perrors$O $(OBJDIR)$Pfiles$O $(OBJDIR)$Pkeys$O $(OBJDIR)$Pnames$O $(OBJDIR)$Pserver$O $(OBJDIR)$Pskey$O $(OBJDIR)$Psslio$O $(OBJDIR)$Pta$O $(OBJDIR)$Pvector$O $(OBJDIR)$Pverify$O $(OBJDIR)$Pxmem$O
OBJTESTCRYPTO = $(OBJDIR)$Ptest_crypto$O
OBJTESTSPEED = $(OBJDIR)$Ptest_speed$O
$(OBJDIR)$Pi15_modpow$O: src$Pint$Pi15_modpow.c $(HEADERSPRIV)
$(CC) $(CFLAGS) $(INCFLAGS) $(CCOUT)$(OBJDIR)$Pi15_modpow$O src$Pint$Pi15_modpow.c
+$(OBJDIR)$Pi15_modpow2$O: src$Pint$Pi15_modpow2.c $(HEADERSPRIV)
+ $(CC) $(CFLAGS) $(INCFLAGS) $(CCOUT)$(OBJDIR)$Pi15_modpow2$O src$Pint$Pi15_modpow2.c
+
$(OBJDIR)$Pi15_montmul$O: src$Pint$Pi15_montmul.c $(HEADERSPRIV)
$(CC) $(CFLAGS) $(INCFLAGS) $(CCOUT)$(OBJDIR)$Pi15_montmul$O src$Pint$Pi15_montmul.c
src/int/i15_fmont.c \
src/int/i15_iszero.c \
src/int/i15_modpow.c \
+ src/int/i15_modpow2.c \
src/int/i15_montmul.c \
src/int/i15_mulacc.c \
src/int/i15_muladd.c \
void br_i15_modpow(uint16_t *x, const unsigned char *e, size_t elen,
const uint16_t *m, uint16_t m0i, uint16_t *t1, uint16_t *t2);
+uint32_t br_i15_modpow_opt(uint16_t *x, const unsigned char *e, size_t elen,
+ const uint16_t *m, uint16_t m0i, uint16_t *tmp, size_t twlen);
+
void br_i15_encode(void *dst, size_t len, const uint16_t *x);
uint32_t br_i15_decode_mod(uint16_t *x,
--- /dev/null
+/*
+ * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see inner.h */
+uint32_t
+br_i15_modpow_opt(uint16_t *x,
+ const unsigned char *e, size_t elen,
+ const uint16_t *m, uint16_t m0i, uint16_t *tmp, size_t twlen)
+{
+ size_t mlen, mwlen;
+ uint16_t *t1, *t2, *base;
+ size_t u, v;
+ uint32_t acc;
+ int acc_len, win_len;
+
+ /*
+ * Get modulus size.
+ */
+ mwlen = (m[0] + 31) >> 4;
+ mlen = mwlen * sizeof m[0];
+ t1 = tmp;
+ t2 = tmp + mwlen;
+
+ /*
+ * Compute possible window size, with a maximum of 5 bits.
+ * When the window has size 1 bit, we use a specific code
+ * that requires only two temporaries. Otherwise, for a
+ * window of k bits, we need 2^k+1 temporaries.
+ */
+ if (twlen < (mwlen << 1)) {
+ return 0;
+ }
+ for (win_len = 5; win_len > 1; win_len --) {
+ if ((((uint32_t)1 << win_len) + 1) * mwlen <= twlen) {
+ break;
+ }
+ }
+
+ /*
+ * Everything is done in Montgomery representation.
+ */
+ br_i15_to_monty(x, m);
+
+ /*
+ * Compute window contents. If the window has size one bit only,
+ * then t2 is set to x; otherwise, t2[0] is left untouched, and
+ * t2[k] is set to x^k (for k >= 1).
+ */
+ if (win_len == 1) {
+ memcpy(t2, x, mlen);
+ } else {
+ memcpy(t2 + mwlen, x, mlen);
+ base = t2 + mwlen;
+ for (u = 2; u < ((unsigned)1 << win_len); u ++) {
+ br_i15_montymul(base + mwlen, base, x, m, m0i);
+ base += mwlen;
+ }
+ }
+
+ /*
+ * We need to set x to 1, in Montgomery representation. This can
+ * be done efficiently by setting the high word to 1, then doing
+ * one word-sized shift.
+ */
+ br_i15_zero(x, m[0]);
+ x[mwlen - 1] = 1;
+ br_i15_muladd_small(x, 0, m);
+
+ /*
+ * We process bits from most to least significant. At each
+ * loop iteration, we have acc_len bits in acc.
+ */
+ acc = 0;
+ acc_len = 0;
+ while (acc_len > 0 || elen > 0) {
+ int i, k;
+ uint32_t bits;
+
+ /*
+ * Get the next bits.
+ */
+ k = win_len;
+ if (acc_len < win_len) {
+ if (elen > 0) {
+ acc = (acc << 8) | *e ++;
+ elen --;
+ acc_len += 8;
+ } else {
+ k = acc_len;
+ }
+ }
+ bits = (acc >> (acc_len - k)) & (((uint32_t)1 << k) - 1);
+ acc_len -= k;
+
+ /*
+ * We could get exactly k bits. Compute k squarings.
+ */
+ for (i = 0; i < k; i ++) {
+ br_i15_montymul(t1, x, x, m, m0i);
+ memcpy(x, t1, mlen);
+ }
+
+ /*
+ * Window lookup: we want to set t2 to the window
+ * lookup value, assuming the bits are non-zero. If
+ * the window length is 1 bit only, then t2 is
+ * already set; otherwise, we do a constant-time lookup.
+ */
+ if (win_len > 1) {
+ br_i15_zero(t2, m[0]);
+ base = t2 + mwlen;
+ for (u = 1; u < ((uint32_t)1 << k); u ++) {
+ uint32_t m;
+
+ m = -EQ(u, bits);
+ for (v = 1; v < mwlen; v ++) {
+ t2[v] |= m & base[v];
+ }
+ base += mwlen;
+ }
+ }
+
+ /*
+ * Multiply with the looked-up value. We keep the
+ * product only if the exponent bits are not all-zero.
+ */
+ br_i15_montymul(t1, x, t2, m, m0i);
+ CCOPY(NEQ(bits, 0), x, t1, mlen);
+ }
+
+ /*
+ * Convert back from Montgomery representation, and exit.
+ */
+ br_i15_from_monty(x, m, m0i);
+ return 1;
+}
#include "inner.h"
-#define U (1 + ((BR_MAX_RSA_FACTOR + 14) / 15))
+#define U (1 + ((BR_MAX_RSA_FACTOR + 14) / 15))
+#define TLEN (8 * U)
+
+/* obsolete
+static void
+print_int(const char *name, const uint16_t *x)
+{
+ extern int printf(const char *fmt, ...);
+ unsigned char tmp[1000];
+ size_t u, len;
+
+ len = (x[0] - (x[0] >> 4) + 7) >> 3;
+ br_i15_encode(tmp, len, x);
+ printf("%s = ", name);
+ for (u = 0; u < len; u ++) {
+ printf("%02X", tmp[u]);
+ }
+ printf("\n");
+}
+*/
/* see bearssl_rsa.h */
uint32_t
{
const unsigned char *p, *q;
size_t plen, qlen;
- uint16_t tmp[6 * U];
- uint16_t *mp, *mq, *s1, *s2, *t1, *t2, *t3;
+ size_t fwlen;
uint16_t p0i, q0i;
size_t xlen;
+ uint16_t tmp[TLEN];
+ long z;
+ uint16_t *mp, *mq, *s1, *s2, *t1, *t2, *t3;
+ uint32_t r;
/*
- * All our temporary buffers are from the tmp[] array.
- *
- * The mp, mq, s1, s2, t1 and t2 buffers are large enough to
- * contain a RSA factor. The t3 buffer can contain a complete
- * RSA modulus. t3 shares its storage space with s2, s1 and t1,
- * in that order (this is important, see below).
- */
- mq = tmp;
- mp = tmp + U;
- t2 = tmp + 2 * U;
- s2 = tmp + 3 * U;
- s1 = tmp + 4 * U;
- t1 = tmp + 5 * U;
- t3 = s2;
-
- /*
- * Compute the actual lengths (in bytes) of p and q, and check
- * that they fit within our stack buffers.
+ * Compute the actual lengths of p and q, in bytes.
+ * These lengths are not considered secret (we cannot really hide
+ * them anyway in constant-time code).
*/
p = sk->p;
plen = sk->plen;
q ++;
qlen --;
}
- if (plen > (BR_MAX_RSA_FACTOR >> 3)
- || qlen > (BR_MAX_RSA_FACTOR >> 3))
- {
- return 0;
+
+ /*
+ * Compute the maximum factor length, in words.
+ */
+ z = (long)(plen > qlen ? plen : qlen) << 3;
+ fwlen = 1;
+ while (z > 0) {
+ z -= 15;
+ fwlen ++;
}
/*
- * Decode p and q.
+ * We need to fit at least 6 values in the stack buffer.
*/
- br_i15_decode(mp, p, plen);
- br_i15_decode(mq, q, qlen);
+ if (6 * fwlen > TLEN) {
+ return 0;
+ }
/*
* Compute signature length (in bytes).
xlen = (sk->n_bitlen + 7) >> 3;
/*
- * Compute s1 = x^dp mod p.
+ * Decode q.
*/
- p0i = br_i15_ninv15(mp[1]);
- br_i15_decode_reduce(s1, x, xlen, mp);
- br_i15_modpow(s1, sk->dp, sk->dplen, mp, p0i, t1, t2);
+ mq = tmp;
+ br_i15_decode(mq, q, qlen);
/*
* Compute s2 = x^dq mod q.
*/
q0i = br_i15_ninv15(mq[1]);
+ s2 = tmp + fwlen;
br_i15_decode_reduce(s2, x, xlen, mq);
- br_i15_modpow(s2, sk->dq, sk->dqlen, mq, q0i, t1, t2);
+ r = br_i15_modpow_opt(s2, sk->dq, sk->dqlen, mq, q0i,
+ tmp + 2 * fwlen, TLEN - 2 * fwlen);
+
+ /*
+ * Decode p.
+ */
+ mp = tmp + 2 * fwlen;
+ br_i15_decode(mp, p, plen);
+
+ /*
+ * Compute s1 = x^dq mod q.
+ */
+ p0i = br_i15_ninv15(mp[1]);
+ s1 = tmp + 3 * fwlen;
+ br_i15_decode_reduce(s1, x, xlen, mp);
+ r &= br_i15_modpow_opt(s1, sk->dp, sk->dplen, mp, p0i,
+ tmp + 4 * fwlen, TLEN - 4 * fwlen);
/*
* Compute:
* inverse of q modulo p), we also tolerate improperly large
* values for this parameter.
*/
+ t1 = tmp + 4 * fwlen;
+ t2 = tmp + 5 * fwlen;
br_i15_reduce(t2, s2, mp);
br_i15_add(s1, mp, br_i15_sub(s1, t2, 1));
br_i15_to_monty(s1, mp);
* All these operations are non-modular.
*
* We need mq, s2 and t2. We use the t3 buffer as destination.
- * The buffers mp, s1 and t1 are no longer needed. Moreover,
- * the first step is to copy s2 into the destination buffer t3.
- * We thus arranged for t3 to actually share space with s2, and
- * to be followed by the space formerly used by s1 and t1.
+ * The buffers mp, s1 and t1 are no longer needed, so we can
+ * reuse them for t3. Moreover, the first step of the computation
+ * is to copy s2 into t3, after which s2 is not needed. Right
+ * now, mq is in slot 0, s2 is in slot 1, and t2 in slot 5.
+ * Therefore, we have ample room for t3 by simply using s2.
*/
+ t3 = s2;
br_i15_mulacc(t3, mq, t2);
/*
* The only error conditions remaining at that point are invalid
* values for p and q (even integers).
*/
- return p0i & q0i & 1;
+ return p0i & q0i & r;
}
#include "inner.h"
+/*
+ * As a strict minimum, we need four buffers that can hold a
+ * modular integer.
+ */
+#define TLEN (4 * (1 + ((BR_MAX_RSA_SIZE + 14) / 15)))
+
/* see bearssl_rsa.h */
uint32_t
br_rsa_i15_public(unsigned char *x, size_t xlen,
{
const unsigned char *n;
size_t nlen;
- uint16_t m[1 + ((BR_MAX_RSA_SIZE + 14) / 15)];
- uint16_t a[1 + ((BR_MAX_RSA_SIZE + 14) / 15)];
- uint16_t t1[1 + ((BR_MAX_RSA_SIZE + 14) / 15)];
- uint16_t t2[1 + ((BR_MAX_RSA_SIZE + 14) / 15)];
+ uint16_t tmp[TLEN];
+ uint16_t *m, *a, *t;
+ size_t fwlen;
+ long z;
uint16_t m0i;
uint32_t r;
if (nlen == 0 || nlen > (BR_MAX_RSA_SIZE >> 3) || xlen != nlen) {
return 0;
}
+ z = (long)nlen << 3;
+ fwlen = 1;
+ while (z > 0) {
+ z -= 15;
+ fwlen ++;
+ }
+
+ /*
+ * The modulus gets decoded into m[].
+ * The value to exponentiate goes into a[].
+ * The temporaries for modular exponentiations are in t[].
+ */
+ m = tmp;
+ a = tmp + fwlen;
+ t = tmp + 2 * fwlen;
+
+ /*
+ * Decode the modulus.
+ */
br_i15_decode(m, n, nlen);
m0i = br_i15_ninv15(m[1]);
/*
* Compute the modular exponentiation.
*/
- br_i15_modpow(a, pk->e, pk->elen, m, m0i, t1, t2);
+ br_i15_modpow_opt(a, pk->e, pk->elen, m, m0i, t, TLEN - 2 * fwlen);
/*
* Encode the result.
projects / BearSSL / commitdiff