PSBTv2 (BIP-370) Support

src/embit/bip39.py

@@ -11,7 +11,7 @@ def mnemonic_to_bytes(mnemonic: str, ignore_checksum: bool = False, wordlist=WOR
     # this function is copied from Jimmy Song's HDPrivateKey.from_mnemonic() method
 
     words = mnemonic.strip().split()
-    if len(words) % 3 != 0 or len(words) < 12:
+    if len(words) % 3 != 0 or not 12 <= len(words) <= 24:
         raise ValueError("Invalid recovery phrase")
 
     binary_seed = bytearray()
@@ -97,7 +97,7 @@ def _extract_index(bits, b, n):
 
 
 def mnemonic_from_bytes(entropy, wordlist=WORDLIST):
-    if len(entropy) % 4 != 0:
+    if len(entropy) % 4 != 0 or not 16 <= len(entropy) <= 32:
         raise ValueError("Byte array should be multiple of 4 long (16, 20, ..., 32)")
     total_bits = len(entropy) * 8
     checksum_bits = total_bits // 32

src/embit/descriptor/descriptor.py

@@ -59,6 +59,9 @@ def script_len(self):
 
     @property
     def num_branches(self):
+        if self.miniscript is not None:
+            return max({k.num_branches for k in self.miniscript.keys})
+
         return max([k.num_branches for k in self.keys])
 
     def branch(self, branch_index=None):

src/embit/descriptor/miniscript.py

@@ -54,11 +54,25 @@ def type(self):
 
     @classmethod
     def read_from(cls, s, taproot=False):
-        op, char = read_until(s, b"(")
+        def wrapped(m_script):
+            for w in reversed(wrappers):
+                if w not in WRAPPER_NAMES:
+                    raise MiniscriptError("Unknown wrapper")
+                WrapperCls = WRAPPERS[WRAPPER_NAMES.index(w)]
+                m_script = WrapperCls(m_script, taproot=taproot)
+            return m_script
+
+        op, char = read_until(s, b"(,)")
+        if char in (b",", b")"):
+            s.seek(-1, 1)
         op = op.decode()
         wrappers = ""
         if ":" in op:
             wrappers, op = op.split(":")
+        # handle boolean literals: 0 or 1
+        if op in ("0", "1"):
+            miniscript = JustOne() if op == "1" else JustZero()
+            return wrapped(miniscript)
         if char != b"(":
             raise MiniscriptError("Missing operator")
         if op not in OPERATOR_NAMES:
@@ -67,12 +81,7 @@ def read_from(cls, s, taproot=False):
         MiniscriptCls = OPERATORS[OPERATOR_NAMES.index(op)]
         args = MiniscriptCls.read_arguments(s, taproot=taproot)
         miniscript = MiniscriptCls(*args, taproot=taproot)
-        for w in reversed(wrappers):
-            if w not in WRAPPER_NAMES:
-                raise MiniscriptError("Unknown wrapper")
-            WrapperCls = WRAPPERS[WRAPPER_NAMES.index(w)]
-            miniscript = WrapperCls(miniscript, taproot=taproot)
-        return miniscript
+        return wrapped(miniscript)
 
     @classmethod
     def read_arguments(cls, s, taproot=False):
@@ -119,6 +128,28 @@ def len_args(self):
 ########### Known fragments (miniscript operators) ##############
 
 
+class JustZero(Miniscript):
+    TYPE = "B"
+    PROPS = "zud"
+
+    def inner_compile(self):
+        return Number(0).compile()
+
+    def __str__(self):
+        return "0"
+
+
+class JustOne(Miniscript):
+    TYPE = "B"
+    PROPS = "zu"
+
+    def inner_compile(self):
+        return Number(1).compile()
+
+    def __str__(self):
+        return "1"
+
+
 class OneArg(Miniscript):
     NARGS = 1
 
@@ -870,6 +901,11 @@ def inner_compile(self):
 
     def __len__(self):
         return len(self.arg) + 1
+
+    def verify(self):
+        super().verify()
+        if self.arg.type != "V":
+            raise MiniscriptError("t: X must be of type V")
 
     @property
     def properties(self):

src/embit/liquid/pset.py

@@ -138,10 +138,10 @@ def blinded_vin(self):
             witness=TxInWitness(self.issue_rangeproof, self.token_rangeproof),
         )
 
-    def read_value(self, stream, k):
+    def read_value(self, stream, k, version=None):
         # standard bitcoin stuff
         if (b"\xfc\x08elements" not in k) and (b"\xfc\x04pset" not in k):
-            super().read_value(stream, k)
+            super().read_value(stream, k, version=version)
         elif k == b"\xfc\x04pset\x0e":
             # range proof is very large,
             # so we don't load it if compress flag is set.
@@ -384,9 +384,9 @@ def reblind(self, nonce, blinding_pubkey=None, extra_message=b""):
             secp256k1.generator_parse(self.asset_commitment),
         )
 
-    def read_value(self, stream, k):
+    def read_value(self, stream, k, version=None):
         if (b"\xfc\x08elements" not in k) and (b"\xfc\x04pset" not in k):
-            super().read_value(stream, k)
+            super().read_value(stream, k, version=version)
         # range proof and surjection proof are very large,
         # so we don't load them if compress flag is set.
         elif k in [b"\xfc\x08elements\x04", b"\xfc\x04pset\x04"]: