Make bitcoin.core.bignum internal use

May be replaced, as was done in Bitcoin Core

Author: petertodd

README

@@ -26,7 +26,6 @@ consensus critical and non-consensus-critical.
 
 bitcoin.core            - Basic core definitions, datastructures, and
                           (context-independent) validation
-bitcoin.core.bignum     - Bignum handling
 bitcoin.core.key        - ECC pubkeys
 bitcoin.core.script     - Scripts and opcodes
 bitcoin.core.scripteval - Script evaluation/verification

bitcoin/core/bignum.py renamed to bitcoin/core/_bignum.py

@@ -9,7 +9,9 @@
 # propagated, or distributed except according to the terms contained in the
 # LICENSE file.
 
-"""Bignum routines"""
+# Bignum routines
+#
+# Internally used for script evaluation; not to be used externally.
 
 from __future__ import absolute_import, division, print_function, unicode_literals
 

bitcoin/core/script.py

@@ -29,7 +29,7 @@
 import struct
 
 import bitcoin.core
-import bitcoin.core.bignum
+import bitcoin.core._bignum
 
 MAX_SCRIPT_SIZE = 10000
 MAX_SCRIPT_ELEMENT_SIZE = 520
@@ -521,7 +521,7 @@ def __coerce_instance(cls, other):
             elif other == -1:
                 other = bytes(_bchr(OP_1NEGATE))
             else:
-                other = CScriptOp.encode_op_pushdata(bitcoin.core.bignum.bn2vch(other))
+                other = CScriptOp.encode_op_pushdata(bitcoin.core._bignum.bn2vch(other))
         elif isinstance(other, (bytes, bytearray)):
             other = CScriptOp.encode_op_pushdata(other)
         return other

bitcoin/core/scripteval.py

@@ -28,6 +28,7 @@
 import hashlib
 
 import bitcoin.core
+import bitcoin.core._bignum
 import bitcoin.core.key
 import bitcoin.core.serialize
 
@@ -96,7 +97,7 @@ def __init__(self, opcode, **kwargs):
                                                   **kwargs)
 
 def _CastToBigNum(s, err_raiser):
-    v = bitcoin.core.bignum.vch2bn(s)
+    v = bitcoin.core._bignum.vch2bn(s)
     if len(s) > MAX_NUM_SIZE:
         raise err_raiser(EvalScriptError, 'CastToBigNum() : overflow')
     return v
@@ -239,7 +240,7 @@ def _UnaryOp(opcode, stack, err_raiser):
     else:
         raise AssertionError("Unknown unary opcode encountered; this should not happen")
 
-    stack.append(bitcoin.core.bignum.bn2vch(bn))
+    stack.append(bitcoin.core._bignum.bn2vch(bn))
 
 
 # OP_LSHIFT and OP_RSHIFT are *not* included in this list as they are disabled
@@ -326,7 +327,7 @@ def _BinOp(opcode, stack, err_raiser):
 
     stack.pop()
     stack.pop()
-    stack.append(bitcoin.core.bignum.bn2vch(bn))
+    stack.append(bitcoin.core._bignum.bn2vch(bn))
 
 
 def _CheckExec(vfExec):
@@ -399,7 +400,7 @@ def check_args(n):
 
             if sop == OP_1NEGATE or ((sop >= OP_1) and (sop <= OP_16)):
                 v = sop - (OP_1 - 1)
-                stack.append(bitcoin.core.bignum.bn2vch(v))
+                stack.append(bitcoin.core._bignum.bn2vch(v))
 
             elif sop in _ISA_BINOP:
                 _BinOp(sop, stack, err_raiser)
@@ -490,7 +491,7 @@ def check_args(n):
 
             elif sop == OP_DEPTH:
                 bn = len(stack)
-                stack.append(bitcoin.core.bignum.bn2vch(bn))
+                stack.append(bitcoin.core._bignum.bn2vch(bn))
 
             elif sop == OP_DROP:
                 check_args(1)
@@ -610,7 +611,7 @@ def check_args(n):
             elif sop == OP_SIZE:
                 check_args(1)
                 bn = len(stack[-1])
-                stack.append(bitcoin.core.bignum.bn2vch(bn))
+                stack.append(bitcoin.core._bignum.bn2vch(bn))
 
             elif sop == OP_SHA1:
                 check_args(1)