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Diffstat (limited to 'libgo/go/crypto/elliptic/elliptic.go')
| -rw-r--r-- | libgo/go/crypto/elliptic/elliptic.go | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/libgo/go/crypto/elliptic/elliptic.go b/libgo/go/crypto/elliptic/elliptic.go index e6b59c5..c02df45 100644 --- a/libgo/go/crypto/elliptic/elliptic.go +++ b/libgo/go/crypto/elliptic/elliptic.go @@ -274,7 +274,8 @@ var mask = []byte{0xff, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f} // GenerateKey returns a public/private key pair. The private key is // generated using the given reader, which must return random data. func GenerateKey(curve Curve, rand io.Reader) (priv []byte, x, y *big.Int, err error) { - bitSize := curve.Params().BitSize + N := curve.Params().N + bitSize := N.BitLen() byteLen := (bitSize + 7) >> 3 priv = make([]byte, byteLen) @@ -289,6 +290,12 @@ func GenerateKey(curve Curve, rand io.Reader) (priv []byte, x, y *big.Int, err e // This is because, in tests, rand will return all zeros and we don't // want to get the point at infinity and loop forever. priv[1] ^= 0x42 + + // If the scalar is out of range, sample another random number. + if new(big.Int).SetBytes(priv).Cmp(N) >= 0 { + continue + } + x, y = curve.ScalarBaseMult(priv) } return |