BIP141: Witness program

1 files changed, 18 insertions, 0 deletions

diff --git a/src/script/script.cpp b/src/script/script.cpp
index 6b1eb52bbf..73f5a61bf6 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -210,6 +210,24 @@ bool CScript::IsPayToScriptHash() const
             (*this)[22] == OP_EQUAL);
 }
 
+// A witness program is any valid CScript that consists of a 1-byte push opcode
+// followed by a data push between 2 and 40 bytes.
+bool CScript::IsWitnessProgram(int& version, std::vector<unsigned char>& program) const
+{
+    if (this->size() < 4 || this->size() > 42) {
+        return false;
+    }
+    if ((*this)[0] != OP_0 && ((*this)[0] < OP_1 || (*this)[0] > OP_16)) {
+        return false;
+    }
+    if ((size_t)((*this)[1] + 2) == this->size()) {
+        version = DecodeOP_N((opcodetype)(*this)[0]);
+        program = std::vector<unsigned char>(this->begin() + 2, this->end());
+        return true;
+    }
+    return false;
+}
+
 bool CScript::IsPushOnly(const_iterator pc) const
 {
     while (pc < end())