darkcontract 0.0.5

dark credentials and contracts with multiple attributes and custom schnorr proofs
Documentation
use bls12_381 as bls;

use crate::bls_extensions::*;
use crate::coconut::coconut::*;
use crate::elgamal::*;
use crate::parameters::*;
#[allow(unused_imports)]
use crate::proofs::credential_proof::*;
#[allow(unused_imports)]
use crate::proofs::proof::*;
#[allow(unused_imports)]
use crate::proofs::signature_proof::*;

#[allow(dead_code)]
struct TestValues<'a, R: RngInstance> {
    private_attributes: Vec<bls::Scalar>,
    public_attributes: Vec<bls::Scalar>,
    attribute_keys: Vec<bls::Scalar>,
    blinding_factor: bls::Scalar,
    gamma: ElGamalPublicKey<'a, R>,
    attribute_commit: bls::G1Projective,
    commit_hash: bls::G1Projective,
    ciphertext: Vec<EncryptedValue>,
    blind_commit_hash: bls::G1Projective,
    blind: bls::Scalar,
    verify_key: VerifyKey,
    kappa: bls::G2Projective,
    v: bls::G1Projective,
}

impl<'a, R: RngInstance> TestValues<'a, R> {
    #[allow(dead_code)]
    fn setup(params: &'a Parameters<R>) -> Self {
        Self {
            private_attributes: vec![bls::Scalar::from(110), bls::Scalar::from(4)],
            //public_attributes: vec![bls::Scalar::from(256)],
            public_attributes: Vec::new(),
            attribute_keys: vec![
                bls::Scalar::from_bytes(&[
                    0xec, 0x37, 0x03, 0x7b, 0x33, 0xf4, 0x5c, 0x2e, 0xd0, 0x56, 0xf2, 0x46, 0x43,
                    0xa0, 0xee, 0x01, 0xfb, 0x77, 0xf1, 0xec, 0x95, 0x4b, 0xf2, 0xe5, 0x62, 0x32,
                    0xb5, 0x4e, 0x27, 0xeb, 0xe9, 0x3f,
                ])
                .unwrap(),
                bls::Scalar::from_bytes(&[
                    0xe2, 0x88, 0x9a, 0x7c, 0xc9, 0x37, 0x4d, 0x12, 0x12, 0x92, 0xcb, 0xcd, 0x6c,
                    0x4e, 0x93, 0x63, 0x5a, 0xce, 0x40, 0x14, 0x4f, 0xfc, 0xc8, 0x0b, 0x4c, 0x57,
                    0x65, 0x63, 0x65, 0x49, 0xb2, 0x59,
                ])
                .unwrap(),
            ],

            blinding_factor: bls::Scalar::from_bytes(&[
                0xbd, 0x48, 0x8f, 0xcd, 0xf7, 0x08, 0xd1, 0x36, 0xee, 0x9f, 0xc7, 0xb1, 0xf6, 0x91,
                0xde, 0xf5, 0xc5, 0xfc, 0x48, 0x7c, 0x64, 0x58, 0xad, 0x01, 0x29, 0xb4, 0xd8, 0x1c,
                0xeb, 0xe2, 0x12, 0x5a,
            ])
            .unwrap(),

            gamma: ElGamalPublicKey {
                params: &params,
                public_key: bls::G1Projective::from(
                    bls::G1Affine::from_compressed(&[
                        0xb6, 0xdf, 0x9e, 0x19, 0xbd, 0xca, 0x01, 0xb9, 0x67, 0xe4, 0xf6, 0xff,
                        0x1d, 0x07, 0x53, 0x3a, 0x50, 0x48, 0x7a, 0x71, 0x23, 0xa1, 0x06, 0xd3,
                        0xd8, 0xa1, 0x29, 0x43, 0xee, 0xbe, 0x24, 0x58, 0x9b, 0x93, 0xd7, 0x0b,
                        0xc6, 0xdc, 0x24, 0xaa, 0x56, 0x56, 0x7d, 0x49, 0xd6, 0x6f, 0x31, 0x3e,
                    ])
                    .unwrap(),
                ),
            },

            attribute_commit: bls::G1Projective::from(
                bls::G1Affine::from_compressed(&[
                    0x97, 0x95, 0xba, 0x53, 0xe8, 0xbf, 0x83, 0xbd, 0xf3, 0x23, 0xc6, 0xc9, 0x17,
                    0x4a, 0x41, 0xad, 0xf5, 0x04, 0xdf, 0x3e, 0x49, 0x11, 0x76, 0x74, 0xac, 0xcb,
                    0x24, 0xe6, 0xc5, 0x1a, 0x3e, 0xfc, 0x1f, 0x24, 0x43, 0x0c, 0xce, 0x82, 0x6e,
                    0x78, 0xc8, 0x65, 0xfc, 0x7e, 0xfc, 0x45, 0xf4, 0xfb,
                ])
                .unwrap(),
            ),

            commit_hash: bls::G1Projective::from(
                bls::G1Affine::from_compressed(&[
                    0x83, 0xe8, 0x9d, 0x58, 0xb1, 0x54, 0x48, 0xfa, 0xd4, 0x59, 0x6e, 0x88, 0x42,
                    0xc7, 0x19, 0xd4, 0x65, 0xa8, 0x53, 0xec, 0x87, 0xfe, 0xf5, 0xc3, 0xdc, 0x4e,
                    0x13, 0xaa, 0x5d, 0xb0, 0x3e, 0xa6, 0x0a, 0x1f, 0x22, 0xea, 0x65, 0xaa, 0xd2,
                    0xc5, 0x55, 0xed, 0x37, 0xda, 0x44, 0x41, 0x55, 0x93,
                ])
                .unwrap(),
            ),

            ciphertext: vec![
                (
                    bls::G1Projective::from(
                        bls::G1Affine::from_compressed(&[
                            0x96, 0xbb, 0x5f, 0xe1, 0x01, 0xc9, 0x69, 0x97, 0x3f, 0xb1, 0x74, 0x41,
                            0xae, 0x98, 0xcb, 0x99, 0x8e, 0x70, 0x50, 0x8d, 0x32, 0x29, 0x91, 0x5e,
                            0xaa, 0xb3, 0xba, 0xd6, 0x3a, 0xa4, 0x96, 0x49, 0xf4, 0x63, 0xaa, 0x0d,
                            0x20, 0x60, 0x38, 0x27, 0x76, 0x6d, 0x4b, 0x4a, 0xfc, 0xcd, 0x8a, 0x3c,
                        ])
                        .unwrap(),
                    ),
                    bls::G1Projective::from(
                        bls::G1Affine::from_compressed(&[
                            0xb9, 0xae, 0x56, 0x13, 0xd9, 0xbc, 0x2d, 0xb1, 0xeb, 0x82, 0x4d, 0x91,
                            0x99, 0xdc, 0x27, 0x33, 0xae, 0x68, 0x87, 0x2c, 0x8a, 0xfc, 0xed, 0xbe,
                            0x9c, 0x2f, 0x37, 0x19, 0x6a, 0xb3, 0xf9, 0x05, 0x8d, 0x57, 0xc9, 0x08,
                            0x79, 0x51, 0xf9, 0x5e, 0x2d, 0xae, 0x7d, 0x46, 0x90, 0xe6, 0xac, 0x42,
                        ])
                        .unwrap(),
                    ),
                ),
                (
                    bls::G1Projective::from(
                        bls::G1Affine::from_compressed(&[
                            0x8d, 0x66, 0x78, 0xda, 0x17, 0xcc, 0x6f, 0xa1, 0x96, 0xa7, 0x7f, 0x6d,
                            0x0f, 0x29, 0x5f, 0x01, 0x34, 0x14, 0xec, 0x38, 0xf2, 0x81, 0xc6, 0xea,
                            0x0d, 0x83, 0xe6, 0xb8, 0x40, 0x63, 0x07, 0xf2, 0x9a, 0x6f, 0x24, 0x66,
                            0x5f, 0x22, 0x5f, 0xb4, 0xa3, 0x0c, 0xae, 0x09, 0x29, 0xa4, 0xdd, 0x45,
                        ])
                        .unwrap(),
                    ),
                    bls::G1Projective::from(
                        bls::G1Affine::from_compressed(&[
                            0x96, 0xfd, 0xfe, 0xf3, 0x56, 0x86, 0x6f, 0xa3, 0x82, 0x7a, 0x90, 0x9f,
                            0x76, 0xa8, 0xf2, 0x13, 0x27, 0xb7, 0x4a, 0xb3, 0xd7, 0x32, 0xc7, 0xb8,
                            0xbb, 0xf6, 0x7a, 0x29, 0xf6, 0x23, 0xc8, 0xfa, 0x3d, 0x93, 0x05, 0x05,
                            0xc8, 0x74, 0x7b, 0x75, 0x74, 0xa9, 0x4e, 0x7b, 0x03, 0x49, 0x5c, 0xbc,
                        ])
                        .unwrap(),
                    ),
                ),
            ],

            blind_commit_hash: bls::G1Projective::from(
                bls::G1Affine::from_compressed(&[
                    0x80, 0x81, 0xc6, 0xfb, 0x9b, 0x59, 0x80, 0xd6, 0xf7, 0xbf, 0x51, 0xb9, 0xff,
                    0x76, 0x02, 0x44, 0x6e, 0xed, 0xd2, 0x23, 0x74, 0xf5, 0x11, 0x5e, 0x39, 0x09,
                    0xfc, 0x95, 0x09, 0x25, 0x1d, 0x0c, 0xdd, 0x2a, 0xb1, 0x8d, 0x68, 0x18, 0x60,
                    0x1e, 0x8f, 0x85, 0x94, 0x12, 0xaf, 0x01, 0x80, 0x24,
                ])
                .unwrap(),
            ),

            blind: bls::Scalar::from_bytes(&[
                0x2e, 0xcf, 0x05, 0x0d, 0x66, 0xb3, 0xba, 0xb8, 0x07, 0x3e, 0xbe, 0xad, 0xe1, 0x9d,
                0xa6, 0x85, 0xca, 0xb8, 0xfd, 0x98, 0xfa, 0x07, 0x45, 0xcb, 0xb4, 0x15, 0x3c, 0x1d,
                0x46, 0xcf, 0xd5, 0x39,
            ])
            .unwrap(),

            verify_key: VerifyKey {
                alpha: bls::G2Projective::from(
                    bls::G2Affine::from_compressed(&[
                        0xad, 0x30, 0xc8, 0xe1, 0xd4, 0x5b, 0x3a, 0x3e, 0xa3, 0xc3, 0xf0, 0x82,
                        0x3f, 0x30, 0x0d, 0xac, 0x51, 0x8d, 0x3b, 0x10, 0xb3, 0x3e, 0x8b, 0xdf,
                        0x9b, 0x80, 0x6d, 0x4d, 0x8b, 0xe9, 0x97, 0x69, 0x42, 0xee, 0x67, 0xdd,
                        0x27, 0x19, 0x82, 0xd7, 0x93, 0x49, 0x36, 0x6a, 0x26, 0x21, 0xae, 0xbc,
                        0x16, 0xdc, 0x38, 0x7f, 0xb0, 0x27, 0xfa, 0x48, 0x67, 0x6a, 0x7a, 0xff,
                        0x9f, 0xed, 0xf9, 0xdb, 0x02, 0x6e, 0x3f, 0x4a, 0x9a, 0x93, 0x99, 0x0d,
                        0xfe, 0x07, 0xd0, 0x72, 0x56, 0xbd, 0xd2, 0x38, 0x1c, 0xf4, 0xb2, 0x54,
                        0xb3, 0xa1, 0x72, 0xa1, 0x90, 0x16, 0x81, 0x31, 0xb0, 0xf5, 0xbe, 0xac,
                    ])
                    .unwrap(),
                ),

                beta: vec![
                    bls::G2Projective::from(
                        bls::G2Affine::from_compressed(&[
                            0xaa, 0x9d, 0xb9, 0xd8, 0x7a, 0x33, 0x07, 0xb2, 0xb7, 0x44, 0xd9, 0xa8,
                            0x16, 0x86, 0xf3, 0x60, 0x1b, 0xe3, 0xfe, 0x08, 0x85, 0xc1, 0x6b, 0x0a,
                            0xea, 0xf2, 0x0a, 0xee, 0xaf, 0x46, 0xc5, 0x39, 0x6e, 0x06, 0x1e, 0x05,
                            0x34, 0x2a, 0xea, 0x41, 0xa1, 0xaf, 0xea, 0xff, 0x46, 0x0d, 0xa8, 0x7c,
                            0x04, 0xa1, 0xbd, 0x26, 0x40, 0x50, 0x59, 0x1e, 0xde, 0x1d, 0x13, 0xfc,
                            0x13, 0x79, 0x9f, 0x8c, 0x31, 0x86, 0xef, 0x09, 0x0e, 0x24, 0x01, 0xb3,
                            0x69, 0x2b, 0xef, 0x94, 0x13, 0xec, 0xe9, 0x21, 0xb8, 0x70, 0x9a, 0x54,
                            0x71, 0xc8, 0x0f, 0x51, 0x24, 0x95, 0xaf, 0xfb, 0x49, 0x08, 0xa0, 0xfa,
                        ])
                        .unwrap(),
                    ),
                    bls::G2Projective::from(
                        bls::G2Affine::from_compressed(&[
                            0xae, 0xbd, 0x93, 0x0e, 0x7c, 0x57, 0x44, 0xf2, 0x12, 0xfd, 0x3c, 0x60,
                            0xc5, 0x08, 0xa5, 0x13, 0x7d, 0x92, 0x2b, 0x4c, 0x37, 0x3c, 0x99, 0x9f,
                            0x33, 0xad, 0x49, 0x50, 0x62, 0x45, 0xd8, 0x6d, 0x02, 0x41, 0x14, 0x2d,
                            0x34, 0x4c, 0xa5, 0x6d, 0x1e, 0x67, 0x61, 0x7c, 0x74, 0x68, 0x92, 0xfd,
                            0x09, 0xdb, 0xba, 0xdd, 0x77, 0x80, 0x89, 0xf6, 0xb1, 0x70, 0x16, 0x59,
                            0xc5, 0x7a, 0x92, 0xca, 0xa3, 0x91, 0xd3, 0xb4, 0x92, 0xcf, 0xb5, 0x97,
                            0x80, 0xa2, 0x5b, 0x18, 0x18, 0x04, 0xbe, 0x24, 0x57, 0xf6, 0x0a, 0x44,
                            0x54, 0xa3, 0x57, 0x36, 0x49, 0x44, 0x3f, 0x0f, 0xd3, 0x7c, 0x79, 0x14,
                        ])
                        .unwrap(),
                    ),
                ],
            },

            kappa: bls::G2Projective::from(
                bls::G2Affine::from_compressed(&[
                    0x89, 0x59, 0x75, 0x07, 0x43, 0x5d, 0x40, 0xf9, 0x34, 0x7f, 0x2c, 0x03, 0xd3,
                    0x05, 0xd6, 0x98, 0xd1, 0xe3, 0x4d, 0xd8, 0xcb, 0x1b, 0x7d, 0x97, 0x46, 0x35,
                    0xeb, 0x86, 0xfe, 0x4c, 0x2b, 0x2a, 0x49, 0x50, 0xd9, 0x50, 0x5f, 0x07, 0xd2,
                    0x7f, 0xd3, 0x10, 0x66, 0x2d, 0x48, 0xeb, 0x77, 0xe3, 0x18, 0x91, 0xbb, 0xe6,
                    0xd4, 0xe8, 0x52, 0x44, 0x02, 0xeb, 0xf1, 0x88, 0x9a, 0x46, 0x1d, 0x80, 0x90,
                    0x73, 0x4d, 0xa2, 0x28, 0xa1, 0xac, 0x71, 0x12, 0x3b, 0x42, 0x38, 0xea, 0xc7,
                    0xae, 0x24, 0xdb, 0x03, 0x13, 0x89, 0x9b, 0x6b, 0xcb, 0x45, 0xe4, 0x3e, 0x12,
                    0x8c, 0xf2, 0xa5, 0x3c, 0xda,
                ])
                .unwrap(),
            ),

            v: bls::G1Projective::from(
                bls::G1Affine::from_compressed(&[
                    0x94, 0xc1, 0x76, 0xfb, 0x7a, 0xef, 0x48, 0x63, 0x50, 0xe5, 0x80, 0xa3, 0xdd,
                    0x80, 0x4d, 0x60, 0x59, 0x2d, 0x78, 0x7e, 0x44, 0x7d, 0x18, 0x83, 0xee, 0x30,
                    0x40, 0x1f, 0x46, 0x03, 0x61, 0x0d, 0x90, 0xa8, 0xe5, 0x32, 0x0a, 0xe6, 0x3c,
                    0x97, 0x27, 0x2f, 0xd1, 0xa3, 0xa9, 0x09, 0x31, 0xbd,
                ])
                .unwrap(),
            ),
        }
    }
}

#[test]
fn test_signature_request_proof() {
    let params = Parameters::<OsRngInstance>::new(2);
    let values = TestValues::setup(&params);

    //
    // Signing steps
    //
    // random k
    let proof_builder = SignatureProofBuilder::new(
        &params,
        &values.private_attributes,
        &values.public_attributes,
        &values.attribute_keys,
        &values.blinding_factor,
    );
    // R = k G
    let commitments =
        proof_builder.commitments(&values.gamma, &values.commit_hash, &values.attribute_commit);

    // c = H(R || ...)
    let mut hasher = ProofHasher::new();
    commitments.commit(&mut hasher);
    let challenge = hasher.finish();

    // s = k + c x
    let proof = proof_builder.finish(&challenge);

    //
    // Verify steps
    //
    // R = s G - c P
    let verify_commitments = proof.commitments(
        &params,
        &challenge,
        &values.gamma,
        &values.commit_hash,
        &values.attribute_commit,
        &values.ciphertext,
    );

    // c = H(R || ...)
    let mut verify_hasher = ProofHasher::new();
    verify_commitments.commit(&mut verify_hasher);
    let verify_challenge = verify_hasher.finish();
    // c == c'
    assert_eq!(challenge, verify_challenge);
}

#[test]
fn test_credential_proof() {
    let params = Parameters::<OsRngInstance>::new(3);
    let values = TestValues::setup(&params);

    //
    // Signing steps
    //
    // random k
    let proof_builder =
        CredentialProofBuilder::new(&params, &values.private_attributes, &values.blind);
    // R = k G
    let commitments = proof_builder.commitments(&values.verify_key, &values.blind_commit_hash);

    // c = H(R || ...)
    let mut hasher = ProofHasher::new();
    commitments.commit(&mut hasher);
    let challenge = hasher.finish();

    // s = k + c x
    let proof = proof_builder.finish(&challenge);

    //
    // Verify steps
    //
    // R = s G - c P
    let verify_commitments = proof.commitments(
        &params,
        &challenge,
        &values.verify_key,
        &values.blind_commit_hash,
        &values.kappa,
        &values.v,
    );

    // c = H(R || ...)
    let mut verify_hasher = ProofHasher::new();
    verify_commitments.commit(&mut verify_hasher);
    let verify_challenge = verify_hasher.finish();
    // c == c'
    assert_eq!(challenge, verify_challenge);
}