Ecdsa.sign_loop: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend as Ecdsa
Lines 118-128 of bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&start_line=118&end_line=128

import Base

# step h, with the retry of step h.3 (K = HMAC_K(V || 0x00),
# V = HMAC_K(V)) before the next V = HMAC_K(V); at most `fuel` candidates
def sign_loop(fuel: Nat, +one: Nat, +e: Nat, +d: Nat, +k: List<&2, U32>, +v: List<&2, U32>, att: Attempt) -> Maybe<&2, List<&2, U32>>:
  match fuel att:
    case 0n Retry{}: None{}
    case 0n Sig{sig}: Some{sig}
    case 1n+f Retry{}:
      +k2 = hmac(k, cat(v, [0]))
      +v3 = hmac(k2, hmac(k2, v))
      sign_loop(f, one, e, d, k2, v3, attempt(one, e, d, v3))
    case 1n+f Sig{sig}: Some{sig}

Uses (8):
  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=U32
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=Attempt
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=attempt
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=cat
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/secp256k1/ecdsa.bend&name=hmac