diff options
| author | Jack Lloyd <[email protected]> | 2019-09-12 09:31:26 -0400 |
|---|---|---|
| committer | Jack Lloyd <[email protected]> | 2019-09-12 09:35:43 -0400 |
| commit | 321a50789e6eeda6898af114492445f0882ee70f (patch) | |
| tree | a1f27ca37d1ba8cecc510813b7112108393a4a2a /src/lib/pubkey/ec_group | |
| parent | 71a92630ac1e3d995a017610e82a62ad6c54d246 (diff) | |
Support loading an EC point with affine zero coordinates.
For example it is possible to construct a point with x coordinate of
zero whenenver b has a square root modulo p.
Found during integration with
https://github.com/catenacyber/elliptic-curve-differential-fuzzer
Diffstat (limited to 'src/lib/pubkey/ec_group')
| -rw-r--r-- | src/lib/pubkey/ec_group/point_gfp.cpp | 4 | ||||
| -rw-r--r-- | src/lib/pubkey/ec_group/point_gfp.h | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/src/lib/pubkey/ec_group/point_gfp.cpp b/src/lib/pubkey/ec_group/point_gfp.cpp index 5574a360c..9a9667175 100644 --- a/src/lib/pubkey/ec_group/point_gfp.cpp +++ b/src/lib/pubkey/ec_group/point_gfp.cpp @@ -30,9 +30,9 @@ PointGFp::PointGFp(const CurveGFp& curve, const BigInt& x, const BigInt& y) : m_coord_y(y), m_coord_z(m_curve.get_1_rep()) { - if(x <= 0 || x >= curve.get_p()) + if(x < 0 || x >= curve.get_p()) throw Invalid_Argument("Invalid PointGFp affine x"); - if(y <= 0 || y >= curve.get_p()) + if(y < 0 || y >= curve.get_p()) throw Invalid_Argument("Invalid PointGFp affine y"); secure_vector<word> monty_ws(m_curve.get_ws_size()); diff --git a/src/lib/pubkey/ec_group/point_gfp.h b/src/lib/pubkey/ec_group/point_gfp.h index a233c5b94..bddb6707b 100644 --- a/src/lib/pubkey/ec_group/point_gfp.h +++ b/src/lib/pubkey/ec_group/point_gfp.h @@ -96,6 +96,7 @@ class BOTAN_PUBLIC_API(2,0) PointGFp final /** * Construct a point from its affine coordinates + * Prefer EC_Group::point(x,y) for this operation. * @param curve the base curve * @param x affine x coordinate * @param y affine y coordinate |