Poly1305.poly1305_mac: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/spec/crypto/poly1305.bend as Poly1305
Lines 113-118 of bend-collections@1.0.0.0/spec/crypto/poly1305.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&start_line=113&end_line=118

import Base

# poly1305_mac(msg, key): r = clamp(key[0..16]), s = key[16..32];
# a = 0, absorb every block, a += s; the tag is num_to_16_le_bytes(a).
def poly1305_mac(+key: List<&2, U32>, +msg: List<&2, U32>) -> List<&2, U32>:
  +r = le_num(clamp(prefix(16n, key)))
  +s = le_num(prefix(16n, suffix(16n, key)))
  le_bytes(16n, Nat.add(absorb(blocks(List.length(&2, U32, msg), msg), r, 0n), s))

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  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/poly1305.bend&name=absorb
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=blocks
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=clamp
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=le_bytes
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=le_num
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=prefix
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/poly1305.bend&name=suffix