1 files changed, 107 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/ellipticcurve/publicKey.py b/.venv/lib/python3.12/site-packages/ellipticcurve/publicKey.py
new file mode 100644
index 00000000..3ebb5938
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/ellipticcurve/publicKey.py
@@ -0,0 +1,107 @@
+from .math import Math
+from .point import Point
+from .curve import secp256k1, getByOid
+from .utils.pem import getPemContent, createPem
+from .utils.der import hexFromInt, parse, DerFieldType, encodeConstructed, encodePrimitive
+from .utils.binary import hexFromByteString, byteStringFromHex, intFromHex, base64FromByteString, byteStringFromBase64
+
+
+class PublicKey:
+
+    def __init__(self, point, curve):
+        self.point = point
+        self.curve = curve
+
+    def toString(self, encoded=False):
+        baseLength = 2 * self.curve.length()
+        xHex = hexFromInt(self.point.x).zfill(baseLength)
+        yHex = hexFromInt(self.point.y).zfill(baseLength)
+        string = xHex + yHex
+        if encoded:
+            return "0004" + string
+        return string
+
+    def toCompressed(self):
+        baseLength = 2 * self.curve.length()
+        parityTag = _evenTag if self.point.y % 2 == 0 else _oddTag
+        xHex = hexFromInt(self.point.x).zfill(baseLength)
+        return parityTag + xHex
+
+    def toDer(self):
+        hexadecimal = encodeConstructed(
+            encodeConstructed(
+                encodePrimitive(DerFieldType.object, _ecdsaPublicKeyOid),
+                encodePrimitive(DerFieldType.object, self.curve.oid),
+            ),
+            encodePrimitive(DerFieldType.bitString, self.toString(encoded=True)),
+        )
+        return byteStringFromHex(hexadecimal)
+
+    def toPem(self):
+        der = self.toDer()
+        return createPem(content=base64FromByteString(der), template=_pemTemplate)
+
+    @classmethod
+    def fromPem(cls, string):
+        publicKeyPem = getPemContent(pem=string, template=_pemTemplate)
+        return cls.fromDer(byteStringFromBase64(publicKeyPem))
+
+    @classmethod
+    def fromDer(cls, string):
+        hexadecimal = hexFromByteString(string)
+        curveData, pointString = parse(hexadecimal)[0]
+        publicKeyOid, curveOid = curveData
+        if publicKeyOid != _ecdsaPublicKeyOid:
+            raise Exception("The Public Key Object Identifier (OID) should be {ecdsaPublicKeyOid}, but {actualOid} was found instead".format(
+                ecdsaPublicKeyOid=_ecdsaPublicKeyOid,
+                actualOid=publicKeyOid,
+            ))
+        curve = getByOid(curveOid)
+        return cls.fromString(string=pointString, curve=curve)
+
+    @classmethod
+    def fromString(cls, string, curve=secp256k1, validatePoint=True):
+        baseLength = 2 * curve.length()
+        if len(string) > 2 * baseLength and string[:4] == "0004":
+            string = string[4:]
+
+        xs = string[:baseLength]
+        ys = string[baseLength:]
+
+        p = Point(
+            x=intFromHex(xs),
+            y=intFromHex(ys),
+        )
+        publicKey = PublicKey(point=p, curve=curve)
+        if not validatePoint:
+            return publicKey
+        if p.isAtInfinity():
+            raise Exception("Public Key point is at infinity")
+        if not curve.contains(p):
+            raise Exception("Point ({x},{y}) is not valid for curve {name}".format(x=p.x, y=p.y, name=curve.name))
+        if not Math.multiply(p=p, n=curve.N, N=curve.N, A=curve.A, P=curve.P).isAtInfinity():
+            raise Exception("Point ({x},{y}) * {name}.N is not at infinity".format(x=p.x, y=p.y, name=curve.name))
+        return publicKey
+        
+    @classmethod
+    def fromCompressed(cls, string, curve=secp256k1):
+        parityTag, xHex = string[:2], string[2:]
+        if parityTag not in [_evenTag, _oddTag]:
+            raise Exception("Compressed string should start with 02 or 03")
+        x = intFromHex(xHex)
+        y = curve.y(x, isEven=parityTag == _evenTag)
+        return cls(point=Point(x, y), curve=curve)
+
+
+_evenTag = "02"
+_oddTag = "03"
+
+
+_ecdsaPublicKeyOid = (1, 2, 840, 10045, 2, 1)
+
+
+_pemTemplate = """
+-----BEGIN PUBLIC KEY-----
+{content}
+-----END PUBLIC KEY-----
+"""