1 files changed, 59 insertions, 0 deletions
diff --git a/src/xpit_/identity.py b/src/xpit_/identity.py
new file mode 100644
index 0000000..2786b2d
--- /dev/null
+++ b/src/xpit_/identity.py
@@ -0,0 +1,59 @@
+import os
+import base64
+from sys import stdout
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import ed25519
+from cryptography.hazmat.primitives.asymmetric.types import PrivateKeyTypes, PublicKeyTypes
+
+# TODO guard against bad file access
+def create(path: str) -> None:
+    private_key = ed25519.Ed25519PrivateKey.generate()
+    public_key = private_key.public_key()
+    enc = serialization.NoEncryption()
+
+    os.mkdir(path)
+
+    data = private_key.private_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PrivateFormat.PKCS8,
+        encryption_algorithm=enc,
+    )
+    with open(os.path.join(path, "private.pem"), "wb") as f:
+        f.write(data)
+
+    data = public_key.public_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PublicFormat.SubjectPublicKeyInfo,
+    )
+    with open(os.path.join(path, "public.pub"), "wb") as f:
+        f.write(data)
+
+def load(identities_dir: str, identity: str) -> tuple[PrivateKeyTypes, PublicKeyTypes]:
+    if not os.path.isdir(identities_dir):
+        os.makedirs(identities_dir)
+
+    path = os.path.join(identities_dir, identity)
+
+    if not os.path.isdir(path):
+        stdout.write(f"Generating new identity '{identity}'...\n")
+        create(path)
+        stdout.write(f"Created new identity '{identity}' at: {path}\n")
+
+    with open(os.path.join(path, "private.pem"), "rb") as f:
+        private_key_data = f.read()
+    with open(os.path.join(path, "public.pub"), "rb") as f:
+        public_key_data = f.read()
+
+    return (
+        serialization.load_pem_private_key(private_key_data, password=None),
+        serialization.load_pem_public_key(public_key_data)
+    )
+
+def id_from_pubkey(pubkey: PublicKeyTypes) -> bytes:
+    der = pubkey.public_bytes(
+        encoding=serialization.Encoding.DER,
+        format=serialization.PublicFormat.SubjectPublicKeyInfo,
+    )
+    b64 = base64.b64encode(der)
+    return b64[16:24]
+