The attestation verifier verifies attestations provided by the attestation server containing a secp256k1 public key and signs the response using its own secp256k1 key. Intended to be run inside an enclave to provide cheap attestation verification services.
Once the attestation of the verfier is verified on-chain (very expensive), it enables other enclaves, including other verifiers, to get verified by submitting a simple ECDSA signature from the verifier instead (very cheap). The process essentially extends the chain of trust of the attestation verifier enclave instead of trying to verify the full attestation of the other enclave again.
cargo build --releaseamd64: http://public.artifacts.marlin.pro/projects/enclaves/attestation-verifier_v2.0.1_linux_amd64
arm64: http://public.artifacts.marlin.pro/projects/enclaves/attestation-verifier_v2.0.1_linux_arm64
$ ./target/release/oyster-attestation-verifier --help
Usage: oyster-attestation-verifier --secp256k1-secret <SECP256K1_SECRET> --secp256k1-public <SECP256K1_PUBLIC> --ip <IP> --port <PORT>
Options:
--secp256k1-secret <SECP256K1_SECRET>
path to secp256k1 private key file (e.g. /app/secp256k1.sec)
--secp256k1-public <SECP256K1_PUBLIC>
path to secp256k1 public key file (e.g. /app/secp256k1.pub)
-i, --ip <IP>
server ip (e.g. 127.0.0.1)
-p, --port <PORT>
server port (e.g. 1400)
-h, --help
Print help
-V, --version
Print version
The attestation verifier exposes two verification endpoints which expect the attestation in one of two formats - raw and hex. The formats match the two endpoints of the attestation server and the response of the server can just be sent to the verifier as is.
/verify/raw
$ curl <attestation_server_ip:attestation_server_port>/attestation/raw -vs | curl -H "Content-Type: application/octet-stream" --data-binary @- <attestation_verifier_ip:attestation_verifier_port>/verify/raw -vs
* Trying <attestation_server_ip:attestation_server_port>...
* Connected to <attestation_server_ip> (<attestation_server_ip>) port <attestation_server_port> (#0)
> GET /attestation/raw HTTP/1.1
> Host: <attestation_server_ip:attestation_server_port>
> User-Agent: curl/7.81.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< content-type: application/octet-stream
< content-length: 4468
< date: Sun, 07 Apr 2024 06:36:44 GMT
<
{ [2682 bytes data]
* Connection #0 to host <attestation_server_ip> left intact
* Trying <attestation_verifier_ip:attestation_verifier_port>...
* Connected to <attestation_verifier_ip> (<attestation_verifier_ip>) port <attestation_verifier_port> (#0)
> POST /verify/raw HTTP/1.1
> Host: <attestation_verifier_ip:attestation_verifier_port>
> User-Agent: curl/7.81.0
> Accept: */*
> Content-Type: application/octet-stream
> Content-Length: 4468
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< content-length: 799
< content-type: application/json
< date: Sun, 07 Apr 2024 06:36:44 GMT
<
* Connection #0 to host <attestation_verifier_ip> left intact
{"signature":"1aaffb1463cfbeb24401267d2ab2661a9695dd0fb294fc4f4e66ad98efa1ece63b79c0bfc5d79c8515abbfb4fa50994b848132d3374821ff09eb22c7af37395e1b","secp256k1_public":"e646f8b0071d5ba75931402522cc6a5c42a84a6fea238864e5ac9a0e12d83bd36d0c8109d3ca2b699fce8d082bf313f5d2ae249bb275b6b6e91e0fcd9262f4bb","pcr0":"189038eccf28a3a098949e402f3b3d86a876f4915c5b02d546abb5d8c507ceb1755b8192d8cfca66e8f226160ca4c7a6","pcr1":"5d3938eb05288e20a981038b1861062ff4174884968a39aee5982b312894e60561883576cc7381d1a7d05b809936bd16","pcr2":"6c3ef363c488a9a86faa63a44653fd806e645d4540b40540876f3b811fc1bceecf036a4703f07587c501ee45bb56a1aa","timestamp":1712471793488,"verifier_secp256k1_public":"e646f8b0071d5ba75931402522cc6a5c42a84a6fea238864e5ac9a0e12d83bd36d0c8109d3ca2b699fce8d082bf313f5d2ae249bb275b6b6e91e0fcd9262f4bb"}
/attestation/hex
$ curl <attestation_server_ip:attestation_server_port>/attestation/hex -vs | curl -H "Content-Type: text/plain" -d @- <attestation_verifier_ip:attestation_verifier_port>/verify/hex -vs
* Trying <attestation_server_ip:attestation_server_port>...
* Connected to <attestation_server_ip> (<attestation_server_ip>) port <attestation_server_port> (#0)
> GET /attestation/hex HTTP/1.1
> Host: <attestation_server_ip:attestation_server_port>
> User-Agent: curl/7.81.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< content-type: text/plain; charset=utf-8
< content-length: 8936
< date: Sun, 07 Apr 2024 06:44:25 GMT
<
{ [2681 bytes data]
* Connection #0 to host <attestation_server_ip> left intact
* Trying <attestation_verifier_ip:attestation_verifier_port>...
* Connected to <attestation_verifier_ip> (<attestation_verifier_ip>) port <attestation_verifier_port> (#0)
> POST /verify/hex HTTP/1.1
> Host: <attestation_verifier_ip:attestation_verifier_port>
> User-Agent: curl/7.81.0
> Accept: */*
> Content-Type: text/plain
> Content-Length: 8936
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< content-length: 799
< content-type: application/json
< date: Sun, 07 Apr 2024 06:44:25 GMT
<
* Connection #0 to host <attestation_verifier_ip> left intact
{"signature":"4ed49c703e8deea8dabccbeeb8fe5625776dbbbef4cffbb9c31f84d21e7a0b6c63707aade102548cc05e6de3a49469b96c700f5b8709e75ec050061ac69dbb621c","secp256k1_public":"e646f8b0071d5ba75931402522cc6a5c42a84a6fea238864e5ac9a0e12d83bd36d0c8109d3ca2b699fce8d082bf313f5d2ae249bb275b6b6e91e0fcd9262f4bb","pcr0":"189038eccf28a3a098949e402f3b3d86a876f4915c5b02d546abb5d8c507ceb1755b8192d8cfca66e8f226160ca4c7a6","pcr1":"5d3938eb05288e20a981038b1861062ff4174884968a39aee5982b312894e60561883576cc7381d1a7d05b809936bd16","pcr2":"6c3ef363c488a9a86faa63a44653fd806e645d4540b40540876f3b811fc1bceecf036a4703f07587c501ee45bb56a1aa","timestamp":1712472254392,"verifier_secp256k1_public":"e646f8b0071d5ba75931402522cc6a5c42a84a6fea238864e5ac9a0e12d83bd36d0c8109d3ca2b699fce8d082bf313f5d2ae249bb275b6b6e91e0fcd9262f4bb"}
{
"signature": "...",
"secp256k1_public": "...",
"pcr0": "...",
"pcr1": "...",
"pcr2": "...",
"timestamp": ...,
"verifier_secp256k1_public": "..."
}The verifier responds with JSON with the following fields:
signature: signature provided by the verifiersecp256k1_public: public key that was encoded in the attestationpcr0: PCR0 that was encoded in the attestationpcr1: PCR1 that was encoded in the attestationpcr2: PCR2 that was encoded in the attestationtimestamp: timestamp that was encoded in the attestationverifier_secp256k1_public: public key of the verifier corresponding to the signature
The verifier creates the signature as per the EIP-712 standard.
struct EIP712Domain {
string name = "marlin.oyster.AttestationVerifier",
string version = "1",
}The chainId, verifyingContract and salt fields are omitted because we do not see any significant replay concerns in allowing the signature to be verified on any contract on any chain.
struct Attestation {
bytes enclavePubKey;
bytes PCR0;
bytes PCR1;
bytes PCR2;
uint256 timestampInMilliseconds;
}It is designed to be verified by the following solidity code (taken from the AttestationVerifier contract):
bytes32 private constant DOMAIN_SEPARATOR =
keccak256(
abi.encode(
keccak256("EIP712Domain(string name,string version)"),
keccak256("marlin.oyster.AttestationVerifier"),
keccak256("1")
)
);
bytes32 private constant ATTESTATION_TYPEHASH =
keccak256("Attestation(bytes enclavePubKey,bytes PCR0,bytes PCR1,bytes PCR2,uint256 timestampInMilliseconds)");
function _verify(bytes memory signature, Attestation memory attestation) internal view {
bytes32 hashStruct = keccak256(
abi.encode(
ATTESTATION_TYPEHASH,
keccak256(attestation.enclavePubKey),
keccak256(attestation.PCR0),
keccak256(attestation.PCR1),
keccak256(attestation.PCR2),
attestation.timestampInMilliseconds
)
);
bytes32 digest = keccak256(abi.encodePacked("\x19\x01", DOMAIN_SEPARATOR, hashStruct));
address signer = ECDSA.recover(digest, signature);
...
}