Ecdsa.recover_len: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend as Ecdsa
Lines 231-238 of bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&start_line=231&end_line=238

import Base
import bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/curve.bend as CV

def recover_len(+one: Nat, +h: List<&2, U32>, +sig: List<&2, U32>, ok: Bool) -> Maybe<&2, List<&2, U32>>:
  match ok:
    case True{}:
      +r = CV.os2ip(CV.first(32n, sig))
      +s = CV.os2ip(CV.first(32n, CV.after(32n, sig)))
      +id = U32.to_nat(CV.head(CV.after(64n, sig)))
      recover_ok(one, hash_scalar(one, h), r, s, id, Bool.and(Bool.and(scalar_ok(one, r), scalar_ok(one, s)), Nat.is_lt(id, 4n)))
    case False{}: None{}

Uses (15):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.to_nat
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/curve.bend&name=after
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/curve.bend&name=first
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/curve.bend&name=head
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/curve.bend&name=os2ip
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=hash_scalar
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=recover_ok
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=scalar_ok