mirror of https://github.com/waku-org/nwaku.git
158 lines
9.3 KiB
Nim
158 lines
9.3 KiB
Nim
# this module contains the Nim wrappers for the rln library https://github.com/kilic/rln/blob/3bbec368a4adc68cd5f9bfae80b17e1bbb4ef373/src/ffi.rs
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when (NimMajor, NimMinor) < (1, 4):
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{.push raises: [Defect].}
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else:
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{.push raises: [].}
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import
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os,
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waku_rln_relay_types
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const libPath = "vendor/zerokit/target/release/"
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when defined(Windows):
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const libName* = libPath / "rln.dll"
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elif defined(Linux):
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const libName* = libPath / "librln.so"
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elif defined(MacOsX):
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const libName* = libPath / "librln.dylib"
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# all the following procedures are Nim wrappers for the functions defined in libName
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{.push dynlib: libName, raises: [Defect].}
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## Buffer struct is taken from
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# https://github.com/celo-org/celo-threshold-bls-rs/blob/master/crates/threshold-bls-ffi/src/ffi.rs
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type Buffer* = object
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`ptr`*: ptr uint8
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len*: uint
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######################################################################
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## RLN Zerokit module APIs
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######################################################################
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#------------------------------ Merkle Tree operations -----------------------------------------
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proc update_next_member*(ctx: ptr RLN, input_buffer: ptr Buffer): bool {.importc: "set_next_leaf".}
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## adds an element in the merkle tree to the next available position
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## input_buffer points to the id commitment byte seq
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## the return bool value indicates the success or failure of the operation
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proc delete_member*(ctx: ptr RLN, index: uint): bool {.importc: "delete_leaf".}
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## index is the position of the id commitment key to be deleted from the tree
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## the deleted id commitment key is replaced with a zero leaf
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## the return bool value indicates the success or failure of the operation
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proc get_root*(ctx: ptr RLN, output_buffer: ptr Buffer): bool {.importc: "get_root".}
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## get_root populates the passed pointer output_buffer with the current tree root
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## the output_buffer holds the Merkle tree root of size 32 bytes
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## the return bool value indicates the success or failure of the operation
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proc get_merkle_proof*(ctx: ptr RLN, index: uint, output_buffer: ptr Buffer): bool {.importc: "get_proof".}
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## populates the passed pointer output_buffer with the merkle proof for the leaf at position index in the tree stored by ctx
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## the output_buffer holds a serialized Merkle proof (vector of 32 bytes nodes)
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## the return bool value indicates the success or failure of the operation
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proc set_leaf*(ctx: ptr RLN, index: uint, input_buffer: ptr Buffer): bool {.importc: "set_leaf".}
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## sets the leaf at position index in the tree stored by ctx to the value passed by input_buffer
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## the input_buffer holds a serialized leaf of 32 bytes
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## the return bool value indicates the success or failure of the operation
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proc set_leaves*(ctx: ptr RLN, input_buffer: ptr Buffer): bool {.importc: "set_leaves".}
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## sets multiple leaves in the tree stored by ctx to the value passed by input_buffer
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## the input_buffer holds a serialized vector of leaves (32 bytes each)
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## leaves are set one after each other starting from index 0
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## the return bool value indicates the success or failure of the operation
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proc reset_tree*(ctx: ptr RLN, tree_height: uint): bool {.importc: "set_tree".}
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## resets the tree stored by ctx to the the empty tree (all leaves set to 0) of height tree_height
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## the return bool value indicates the success or failure of the operation
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#----------------------------------------------------------------------------------------------
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#-------------------------------- zkSNARKs operations -----------------------------------------
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proc key_gen*(ctx: ptr RLN, output_buffer: ptr Buffer): bool {.importc: "key_gen".}
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## generates id key and id commitment key serialized inside output_buffer as | id_key <32 bytes>| id_commitment_key <32 bytes> |
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## id commitment is the poseidon hash of the id key
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## the return bool value indicates the success or failure of the operation
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proc seeded_key_gen*(ctx: ptr RLN, input_buffer: ptr Buffer, output_buffer: ptr Buffer): bool {.importc: "seeded_key_gen".}
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## generates id key and id commitment key serialized inside output_buffer as | id_key <32 bytes>| id_commitment_key <32 bytes> | using ChaCha20
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## seeded with an arbitrary long seed serialized in input_buffer
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## The input seed provided by the user is hashed using Keccak256 before being passed to ChaCha20 as seed.
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## id commitment is the poseidon hash of the id key
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## the return bool value indicates the success or failure of the operation
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proc generate_proof*(ctx: ptr RLN,
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input_buffer: ptr Buffer,
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output_buffer: ptr Buffer): bool {.importc: "generate_rln_proof".}
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## input_buffer has to be serialized as [ id_key<32> | id_index<8> | epoch<32> | signal_len<8> | signal<var> ]
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## output_buffer holds the proof data and should be parsed as [ proof<128> | root<32> | epoch<32> | share_x<32> | share_y<32> | nullifier<32> | rln_identifier<32> ]
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## integers wrapped in <> indicate value sizes in bytes
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## the return bool value indicates the success or failure of the operation
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proc verify*(ctx: ptr RLN,
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proof_buffer: ptr Buffer,
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proof_is_valid_ptr: ptr bool): bool {.importc: "verify_rln_proof".}
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## proof_buffer has to be serialized as [ proof<128> | root<32> | epoch<32> | share_x<32> | share_y<32> | nullifier<32> | rln_identifier<32> | signal_len<8> | signal<var> ]
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## the return bool value indicates the success or failure of the call to the verify function
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## the verification of the zk proof is available in proof_is_valid_ptr, where a value of true indicates success and false a failure
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proc verify_with_roots*(ctx: ptr RLN,
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proof_buffer: ptr Buffer,
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roots_buffer: ptr Buffer,
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proof_is_valid_ptr: ptr bool): bool {.importc: "verify_with_roots".}
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## proof_buffer has to be serialized as [ proof<128> | root<32> | epoch<32> | share_x<32> | share_y<32> | nullifier<32> | rln_identifier<32> | signal_len<8> | signal<var> ]
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## roots_buffer contains the concatenation of 32 bytes long serializations in little endian of root values
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## the return bool value indicates the success or failure of the call to the verify function
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## the verification of the zk proof is available in proof_is_valid_ptr, where a value of true indicates success and false a failure
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proc zk_prove*(ctx: ptr RLN,
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input_buffer: ptr Buffer,
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output_buffer: ptr Buffer): bool {.importc: "prove".}
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## Computes the zkSNARK proof and stores it in output_buffer for input values stored in input_buffer
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## input_buffer is serialized as input_data as [ id_key<32> | path_elements<Vec<32>> | identity_path_index<Vec<1>> | x<32> | epoch<32> | rln_identifier<32> ]
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## output_buffer holds the proof data and should be parsed as [ proof<128> ]
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## path_elements and indentity_path elements serialize a merkle proof for id_key and are vectors of elements of 32 and 1 bytes, respectively (not. Vec<>).
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## x is the x coordinate of the Shamir's secret share for which the proof is computed
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## epoch is the input epoch (equivalently, the nullifier)
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## the return bool value indicates the success or failure of the operation
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proc zk_verify*(ctx: ptr RLN,
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proof_buffer: ptr Buffer,
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proof_is_valid_ptr: ptr bool): bool {.importc: "verify".}
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## Verifies the zkSNARK proof passed in proof_buffer
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## input_buffer is serialized as input_data as [ proof<128> ]
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## the verification of the zk proof is available in proof_is_valid_ptr, where a value of true indicates success and false a failure
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## the return bool value indicates the success or failure of the operation
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#----------------------------------------------------------------------------------------------
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#-------------------------------- Common procedures -------------------------------------------
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proc new_circuit*(tree_height: uint, input_buffer: ptr Buffer, ctx: ptr (ptr RLN)): bool {.importc: "new".}
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## creates an instance of rln object as defined by the zerokit RLN lib
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## tree_height represent the depth of the Merkle tree
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## input_buffer contains a serialization of the path where the circuit resources can be found (.r1cs, .wasm, .zkey and optionally the verification_key.json)
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## ctx holds the final created rln object
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## the return bool value indicates the success or failure of the operation
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proc new_circuit_from_data*(tree_height: uint, circom_buffer: ptr Buffer, zkey_buffer: ptr Buffer, vk_buffer: ptr Buffer, ctx: ptr (ptr RLN)): bool {.importc: "new_with_params".}
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## creates an instance of rln object as defined by the zerokit RLN lib by passing the required inputs as byte arrays
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## tree_height represent the depth of the Merkle tree
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## circom_buffer contains the bytes read from the Circom .wasm circuit
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## zkey_buffer contains the bytes read from the .zkey proving key
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## vk_buffer contains the bytes read from the verification_key.json
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## ctx holds the final created rln object
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## the return bool value indicates the success or failure of the operation
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proc hash*(ctx: ptr RLN,
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input_buffer: ptr Buffer,
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output_buffer: ptr Buffer): bool {.importc: "hash".}
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## it hashes (sha256) the plain text supplied in inputs_buffer and then maps it to a field element
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## this proc is used to map arbitrary signals to field element for the sake of proof generation
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## inputs_buffer holds the hash input as a byte seq
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## the hash output is generated and populated inside output_buffer
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## the output_buffer contains 32 bytes hash output
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{.pop.}
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