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handle case when encoded key is (p-1)/2

pull/1491/head
orignal 5 years ago
parent
commit
36eaaa748c
  1. 2
      libi2pd/Elligator.cpp
  2. 13
      tests/test-elligator.cpp

2
libi2pd/Elligator.cpp

@ -100,7 +100,7 @@ namespace crypto @@ -100,7 +100,7 @@ namespace crypto
BIGNUM * r = BN_CTX_get (ctx); BN_bin2bn (encoded1, 32, r);
if (BN_cmp (r, p12) < 0) // r < (p-1)/2
if (BN_cmp (r, p12) <= 0) // r < (p-1)/2
{
// v = -A/(1+u*r^2)
BIGNUM * v = BN_CTX_get (ctx); BN_mod_sqr (v, r, p, ctx);

13
tests/test-elligator.cpp

@ -40,6 +40,17 @@ const uint8_t key2[32] = @@ -40,6 +40,17 @@ const uint8_t key2[32] =
0xe5, 0x78, 0x2b, 0xe1, 0xe1, 0x14, 0x5c, 0xe2, 0xc3, 0xc6, 0xfd, 0xe1, 0x6d, 0xed, 0x53, 0x63
};
const uint8_t encoded3[32] =
{
0xf6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f
};
const uint8_t key3[32] =
{
0x9c, 0xdb, 0x52, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55,
0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55
};
int main ()
{
@ -53,4 +64,6 @@ int main () @@ -53,4 +64,6 @@ int main ()
assert(memcmp (buf, key1, 32) == 0);
el.Decode (encoded2, buf);
assert(memcmp (buf, key2, 32) == 0);
el.Decode (encoded3, buf);
assert(memcmp (buf, key3, 32) == 0);
}

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