keybase sign

Closes oconnor663#2.

clinacl.py

@@ -19,9 +19,12 @@
     clinacl verifygen <signingkey>
     clinacl sign <signingkey>
     clinacl verify <verifykey>
-    clinacl keybase
+    clinacl keybase sign <signingkey>
+    clinacl keybase verify
 """
 
+NACL_SIG_LEN = 64
+
 
 def to_hex(bytes):
     return binascii.hexlify(bytes).decode('ascii')
@@ -102,7 +105,33 @@ def verify(keyhex):
     write_to_stdout(plainbytes)
 
 
-def keybase():
+def keybase_sign(keyhex):
+    signing_keybytes = from_hex(keyhex)
+    signingkey = nacl.signing.SigningKey(signing_keybytes)
+    verify_keybytes = signingkey.verify_key.encode()
+    plainbytes = read_from_stdin()
+    attached_sig = signingkey.sign(plainbytes)
+    detatched_sig = attached_sig[:NACL_SIG_LEN]
+    # This is the signature format currently used by Keybase's servers. See the
+    # comments in keybase_verify().
+    blob = {
+        'body': {
+            'payload': plainbytes,
+            'key': b'\x01\x20' + verify_keybytes + b'\x0a',
+            'sig': detatched_sig,
+            'detached': True,
+            'sig_type': 32,
+            'hash_type': 10
+        },
+        'tag': 514,
+        'version': 1,
+    }
+    sig_msgpack_bytes = umsgpack.packb(blob)
+    sig_base64 = base64.b64encode(sig_msgpack_bytes)
+    write_to_stdout(sig_base64)
+
+
+def keybase_verify():
     # A Keybase NaCl signature is a Base64-encoded MessagePack blob containing
     # the payload, the signing KID, and the detatched signature bytes. We
     # decode, unpack, and then verify the signature. If it's valid, we print
@@ -133,12 +162,16 @@ def main():
         signinggen()
     elif args['verifygen']:
         verifygen(args['<signingkey>'])
-    elif args['sign']:
-        sign(args['<signingkey>'])
-    elif args['verify']:
-        verify(args['<verifykey>'])
     elif args['keybase']:
-        keybase()
+        if args['sign']:
+            keybase_sign(args['<signingkey>'])
+        elif args['verify']:
+            keybase_verify()
+    else:
+        if args['sign']:
+            sign(args['<signingkey>'])
+        elif args['verify']:
+            verify(args['<verifykey>'])
 
 
 if __name__ == '__main__':

test.sh

@@ -30,8 +30,10 @@ runtests() {
   echo verified | clinacl sign $signingkey | clinacl verify $verifykey
 
   link='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'
-  echo $link | clinacl keybase
+  echo $link | clinacl keybase verify
   echo
+
+  echo keybase verified | clinacl keybase sign $signingkey | clinacl keybase verify
 }
 
 echo === testing Python 2 ===