Why is policy valid with rust miniscript but throws a compile error on the sipa site?

External question — Bitcoin Stack Exchange Author: jiamijiang Original post: https://bitcoin.stackexchange.com/questions/131089 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Here's a policy I want to get working: or(pk(MAIN),or(thresh(2,pk(KEY_1),pk(KEY_2),pk(KEY_3)),and(sha256(HASH_TARGET),older(144)))) It parses without issue in code: ... let policy_string = format! ( "or(pk({}),or(thresh(2,pk({}),pk({}),pk({})),and(sha256({}),older(144))))", pub_main_key, pub_a_key, pub_b_key, pub_c_key, hash_target ); let policy: Concrete<DescriptorPublicKey> = policy_string.parse() .expect("valid policy"); println!("{:#?}", {policy.to_string()}); ... But it throws a compile error when testing it in the 'Policy to Miniscript compiler' section of bitcoin.sipa.be/miniscript

External answer — Bitcoin Stack Exchange Author: Pieter Wuille Original post: https://bitcoin.stackexchange.com/a/131090 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Two issues: My site does not allow generic symbolic names for hash preimages, only for keys. You can use H however as a stand-in for a hash. My site does not allow malleable scripts. Yours allows satisfying by just revealing the preimage after 144 blocks, which is inherently malleable as it involves no signatures. The following works: or(pk(MAIN),or(thresh(2,pk(KEY_1),pk(KEY_2),pk(KEY_3)),and(sha256(H),and(older(144),pk(F)))))