diff options
| -rw-r--r-- | networking/tls_fe.c | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/networking/tls_fe.c b/networking/tls_fe.c index e96b332..ecb4102 100644 --- a/networking/tls_fe.c +++ b/networking/tls_fe.c @@ -108,26 +108,26 @@ static void raw_try_sub(byte *x, const byte *p) #if 0 //UNUSED static int prime_msb(const byte *p) { - int i; - byte x; - int shift = 1; - int z = F25519_SIZE - 1; - - /* - Test for any hot bits. - As soon as one instance is encountered set shift to 0. - */ + int i; + byte x; + int shift = 1; + int z = F25519_SIZE - 1; + + /* + Test for any hot bits. + As soon as one instance is encountered set shift to 0. + */ for (i = F25519_SIZE - 1; i >= 0; i--) { - shift &= ((shift ^ ((-p[i] | p[i]) >> 7)) & 1); - z -= shift; - } + shift &= ((shift ^ ((-p[i] | p[i]) >> 7)) & 1); + z -= shift; + } x = p[z]; z <<= 3; - shift = 1; - for (i = 0; i < 8; i++) { - shift &= ((-(x >> i) | (x >> i)) >> (7 - i) & 1); - z += shift; - } + shift = 1; + for (i = 0; i < 8; i++) { + shift &= ((-(x >> i) | (x >> i)) >> (7 - i) & 1); + z += shift; + } return z - 1; } @@ -549,6 +549,9 @@ static void curve25519(byte *result, const byte *e, const byte *q) int i; struct { + /* for bbox's special case of q == NULL meaning "use basepoint" */ + /*static const*/ uint8_t basepoint9[CURVE25519_KEYSIZE]; // = {9}; + /* from wolfssl-3.15.3/wolfssl/wolfcrypt/fe_operations.h */ /*static const*/ byte f25519_one[F25519_SIZE]; // = {1}; @@ -559,6 +562,7 @@ static void curve25519(byte *result, const byte *e, const byte *q) byte xm1[F25519_SIZE]; // = {1}; byte zm1[F25519_SIZE]; // = {0}; } z; +#define basepoint9 z.basepoint9 #define f25519_one z.f25519_one #define xm z.xm #define zm z.zm @@ -569,6 +573,11 @@ static void curve25519(byte *result, const byte *e, const byte *q) zm[0] = 1; xm1[0] = 1; + if (!q) { + basepoint9[0] = 9; + q = basepoint9; + } + /* Note: bit 254 is assumed to be 1 */ lm_copy(xm, q); @@ -606,7 +615,6 @@ void FAST_FUNC curve_x25519_compute_pubkey_and_premaster( uint8_t *pubkey, uint8_t *premaster, const uint8_t *peerkey32) { - static const uint8_t basepoint9[CURVE25519_KEYSIZE] ALIGN8 = {9}; uint8_t privkey[CURVE25519_KEYSIZE]; //[32] /* Generate random private key, see RFC 7748 */ @@ -615,7 +623,7 @@ void FAST_FUNC curve_x25519_compute_pubkey_and_premaster( privkey[CURVE25519_KEYSIZE-1] = ((privkey[CURVE25519_KEYSIZE-1] & 0x7f) | 0x40); /* Compute public key */ - curve25519(pubkey, privkey, basepoint9); + curve25519(pubkey, privkey, NULL /* "use base point of x25519" */); /* Compute premaster using peer's public key */ curve25519(premaster, privkey, peerkey32); |