Octet string. One major pain point is having to workaround the "octet string" introduced by Milagro Crypto (probably to workaround C limitations that Nim doesn't have).
This octet string requires a lot of boilerplate and a high-level API that hides away all of this need to be built on top of Milagro-Crypto.
Boilerplate means allocating a storage backend with the proper size and lifetime (arrays are collected when function exists).
typedef chunk BIG_384_29[NLEN_384_29]; /**< Define type BIG as array of chunks */
Other low-level types are stack objects are more straightforward.
FP ~ field point,
ECP_BLS381 ~ field point on elliptic curve,
FP2 ~ complex field point (with real and imaginary part)
ECP2_BLS381 ~complex points on elliptic curve
Need to provide glue
To manage lifetimes properly, we will probably need glue, but also need to develop constant-time primitives to not grow the attack surface mentionned in #2.
mratsim
commented
6 years ago
Unfortunately, Milagro Crypto doesn't come with aggregate signatures so they must be implemented in C or Nim.
We can follow implementation in Rust done here: https://github.com/lovesh/signature-schemes.
Challenges
Octet string. One major pain point is having to workaround the "octet string" introduced by Milagro Crypto (probably to workaround C limitations that Nim doesn't have).
This octet string requires a lot of boilerplate and a high-level API that hides away all of this need to be built on top of Milagro-Crypto.
Boilerplate means allocating a storage backend with the proper size and lifetime (arrays are collected when function exists).
https://github.com/status-im/nim-milagro-crypto/blob/9ad68657cf0d6c238220a3b35efd62fddd6b2ab5/tests/all_tests.nim#L58-L93
Need to wrap lots of low level types and primitives
BIG. The big int implementation also brings problem due to pointers/lifetime/array passing in C. https://github.com/status-im/nim-milagro-crypto/blob/9ad68657cf0d6c238220a3b35efd62fddd6b2ab5/src/generated/big_384_29.h#L39-L60
Other low-level types are stack objects are more straightforward.
Need to provide glue
To manage lifetimes properly, we will probably need glue, but also need to develop constant-time primitives to not grow the attack surface mentionned in #2.