1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
use bn::BigNumber;
use cl::*;
use cl::constants::{LARGE_E_START_VALUE, ITERATION};
use cl::helpers::*;
use errors::prelude::*;

use std::collections::BTreeSet;
use std::iter::FromIterator;
use utils::get_hash_as_int;

/// Party that wants to check that prover has some credentials provided by issuer.
pub struct Verifier {}

impl Verifier {
    /// Creates and returns sub proof request entity builder.
    /// Part of proof request related to a particular schema-key.
    ///
    /// The purpose of sub proof request builder is building of sub proof request entity that
    /// represents requested attributes and predicates.
    ///
    /// # Example
    /// ```
    /// use indy_crypto::cl::verifier::Verifier;
    ///
    /// let mut sub_proof_request_builder = Verifier::new_sub_proof_request_builder().unwrap();
    /// sub_proof_request_builder.add_revealed_attr("name").unwrap();
    /// sub_proof_request_builder.add_predicate("age", "GE", 18).unwrap();
    /// let _sub_proof_request = sub_proof_request_builder.finalize().unwrap();
    /// ```
    pub fn new_sub_proof_request_builder() -> IndyCryptoResult<SubProofRequestBuilder> {
        let res = SubProofRequestBuilder::new()?;
        Ok(res)
    }

    /// Creates and returns proof verifier.
    ///
    /// The purpose of `proof verifier` is check proof provided by Prover.
    ///
    /// # Example
    /// ```
    /// use indy_crypto::cl::verifier::Verifier;
    ///
    /// let _proof_verifier = Verifier::new_proof_verifier().unwrap();
    /// ```
    pub fn new_proof_verifier() -> IndyCryptoResult<ProofVerifier> {
        Ok(ProofVerifier {
            credentials: Vec::new(),
        })
    }
}


#[derive(Debug)]
pub struct ProofVerifier {
    credentials: Vec<VerifiableCredential>,
}

impl ProofVerifier {
    /// Add sub proof request to proof verifier.
    /// The order of sub-proofs is important: both Prover and Verifier should use the same order.
    ///
    /// # Arguments
    /// * `proof_verifier` - Proof verifier.
    /// * `credential_schema` - Credential schema.
    /// * `credential_pub_key` - Credential public key.
    /// * `rev_reg_pub` - Revocation registry public key.
    /// * `sub_proof_request` - Requested attributes and predicates instance pointer.
    ///
    /// #Example
    /// ```
    /// use indy_crypto::cl::issuer::Issuer;
    /// use indy_crypto::cl::verifier::Verifier;
    ///
    /// let mut credential_schema_builder = Issuer::new_credential_schema_builder().unwrap();
    /// credential_schema_builder.add_attr("sex").unwrap();
    /// let credential_schema = credential_schema_builder.finalize().unwrap();
    ///
    /// let mut non_credential_schema_builder = Issuer::new_non_credential_schema_builder().unwrap();
    /// non_credential_schema_builder.add_attr("master_secret").unwrap();
    /// let non_credential_schema = non_credential_schema_builder.finalize().unwrap();
    ///
    /// let (credential_pub_key, credential_priv_key, cred_key_correctness_proof) = Issuer::new_credential_def(&credential_schema, &non_credential_schema, false).unwrap();
    ///
    /// let (credential_pub_key, _credential_priv_key, _credential_key_correctness_proof) = Issuer::new_credential_def(&credential_schema, &non_credential_schema, false).unwrap();
    ///
    /// let mut sub_proof_request_builder = Verifier::new_sub_proof_request_builder().unwrap();
    /// sub_proof_request_builder.add_revealed_attr("sex").unwrap();
    /// let sub_proof_request = sub_proof_request_builder.finalize().unwrap();
    ///
    /// let mut proof_verifier = Verifier::new_proof_verifier().unwrap();
    ///
    /// proof_verifier.add_sub_proof_request(&sub_proof_request,
    ///                                      &credential_schema,
    ///                                      &non_credential_schema,
    ///                                      &credential_pub_key,
    ///                                      None,
    ///                                      None).unwrap();
    /// ```
    pub fn add_sub_proof_request(&mut self,
                                 sub_proof_request: &SubProofRequest,
                                 credential_schema: &CredentialSchema,
                                 non_credential_schema: &NonCredentialSchema,
                                 credential_pub_key: &CredentialPublicKey,
                                 rev_key_pub: Option<&RevocationKeyPublic>,
                                 rev_reg: Option<&RevocationRegistry>) -> IndyCryptoResult<()> {
        ProofVerifier::_check_add_sub_proof_request_params_consistency(sub_proof_request, credential_schema)?;

        self.credentials.push(VerifiableCredential {
            pub_key: credential_pub_key.clone()?,
            sub_proof_request: sub_proof_request.clone(),
            credential_schema: credential_schema.clone(),
            non_credential_schema: non_credential_schema.clone(),
            rev_key_pub: rev_key_pub.map(Clone::clone),
            rev_reg: rev_reg.map(Clone::clone)
        });
        Ok(())
    }

    /// Verifies proof.
    ///
    /// # Arguments
    /// * `proof_verifier` - Proof verifier.
    /// * `proof` - Proof generated by Prover.
    /// * `nonce` - Nonce.
    ///
    ///
    /// #Example
    /// ```
    /// use indy_crypto::cl::new_nonce;
    /// use indy_crypto::cl::issuer::Issuer;
    /// use indy_crypto::cl::prover::Prover;
    /// use indy_crypto::cl::verifier::Verifier;
    ///
    /// let mut credential_schema_builder = Issuer::new_credential_schema_builder().unwrap();
    /// credential_schema_builder.add_attr("sex").unwrap();
    /// let credential_schema = credential_schema_builder.finalize().unwrap();
    ///
    /// let mut non_credential_schema_builder = Issuer::new_non_credential_schema_builder().unwrap();
    /// non_credential_schema_builder.add_attr("master_secret").unwrap();
    /// let non_credential_schema = non_credential_schema_builder.finalize().unwrap();
    ///
    /// let (credential_pub_key, credential_priv_key, cred_key_correctness_proof) = Issuer::new_credential_def(&credential_schema, &non_credential_schema, false).unwrap();
    ///
    /// let master_secret = Prover::new_master_secret().unwrap();
    ///
    /// let mut credential_values_builder = Issuer::new_credential_values_builder().unwrap();
    /// credential_values_builder.add_value_hidden("master_secret", &master_secret.value().unwrap()).unwrap();
    /// credential_values_builder.add_dec_known("sex", "5944657099558967239210949258394887428692050081607692519917050011144233115103").unwrap();
    /// let credential_values = credential_values_builder.finalize().unwrap();
    ///
    /// let credential_nonce = new_nonce().unwrap();
    /// let (blinded_credential_secrets, credential_secrets_blinding_factors, blinded_credential_secrets_correctness_proof) =
    ///     Prover::blind_credential_secrets(&credential_pub_key, &cred_key_correctness_proof, &credential_values, &credential_nonce).unwrap();
    ///
    /// let credential_issuance_nonce = new_nonce().unwrap();
    ///
    /// let (mut credential_signature, signature_correctness_proof) =
    ///     Issuer::sign_credential("CnEDk9HrMnmiHXEV1WFgbVCRteYnPqsJwrTdcZaNhFVW",
    ///                             &blinded_credential_secrets,
    ///                             &blinded_credential_secrets_correctness_proof,
    ///                             &credential_nonce,
    ///                             &credential_issuance_nonce,
    ///                             &credential_values,
    ///                             &credential_pub_key,
    ///                             &credential_priv_key).unwrap();
    ///
    /// Prover::process_credential_signature(&mut credential_signature,
    ///                                      &credential_values,
    ///                                      &signature_correctness_proof,
    ///                                      &credential_secrets_blinding_factors,
    ///                                      &credential_pub_key,
    ///                                      &credential_issuance_nonce,
    ///                                      None, None, None).unwrap();
    ///
    /// let mut sub_proof_request_builder = Verifier::new_sub_proof_request_builder().unwrap();
    /// sub_proof_request_builder.add_revealed_attr("sex").unwrap();
    /// let sub_proof_request = sub_proof_request_builder.finalize().unwrap();
    ///
    /// let mut proof_builder = Prover::new_proof_builder().unwrap();
    /// proof_builder.add_common_attribute("master_secret").unwrap();
    /// proof_builder.add_sub_proof_request(&sub_proof_request,
    ///                                     &credential_schema,
    ///                                     &non_credential_schema,
    ///                                     &credential_signature,
    ///                                     &credential_values,
    ///                                     &credential_pub_key,
    ///                                     None,
    ///                                     None).unwrap();
    ///
    /// let proof_request_nonce = new_nonce().unwrap();
    /// let proof = proof_builder.finalize(&proof_request_nonce).unwrap();
    ///
    /// let mut proof_verifier = Verifier::new_proof_verifier().unwrap();
    ///
    /// proof_verifier.add_sub_proof_request(&sub_proof_request,
    ///                                      &credential_schema,
    ///                                      &non_credential_schema,
    ///                                      &credential_pub_key,
    ///                                      None,
    ///                                      None).unwrap();
    /// assert!(proof_verifier.verify(&proof, &proof_request_nonce).unwrap());
    /// ```
    pub fn verify(&self,
                  proof: &Proof,
                  nonce: &Nonce) -> IndyCryptoResult<bool> {
        trace!("ProofVerifier::verify: >>> proof: {:?}, nonce: {:?}", proof, nonce);

        ProofVerifier::_check_verify_params_consistency(&self.credentials, proof)?;

        let mut tau_list: Vec<Vec<u8>> = Vec::new();

        assert_eq!(proof.proofs.len(), self.credentials.len()); //FIXME return error
        for idx in 0..proof.proofs.len() {
            let proof_item = &proof.proofs[idx];
            let credential = &self.credentials[idx];
            if let (Some(non_revocation_proof), Some(cred_rev_pub_key), Some(rev_reg), Some(rev_key_pub)) = (proof_item.non_revoc_proof.as_ref(),
                                                                                                             credential.pub_key.r_key.as_ref(),
                                                                                                             credential.rev_reg.as_ref(),
                                                                                                             credential.rev_key_pub.as_ref()) {
                tau_list.extend_from_slice(
                    &ProofVerifier::_verify_non_revocation_proof(&cred_rev_pub_key,
                                                                 &rev_reg,
                                                                 &rev_key_pub,
                                                                 &proof.aggregated_proof.c_hash,
                                                                 &non_revocation_proof)?.as_slice()?
                );
            };

            tau_list.append_vec(
                &ProofVerifier::_verify_primary_proof(&credential.pub_key.p_key,
                                                      &proof.aggregated_proof.c_hash,
                                                      &proof_item.primary_proof,
                                                      &credential.credential_schema,
                                                      &credential.non_credential_schema,
                                                      &credential.sub_proof_request)?
            )?;
        }

        let mut values: Vec<Vec<u8>> = Vec::new();
        values.extend_from_slice(&tau_list);
        values.extend_from_slice(&proof.aggregated_proof.c_list);
        values.push(nonce.to_bytes()?);

        let c_hver = get_hash_as_int(&values)?;

        info!(target: "anoncreds_service", "Verifier verify proof -> done");

        let valid = c_hver == proof.aggregated_proof.c_hash;

        trace!("ProofVerifier::verify: <<< valid: {:?}", valid);

        Ok(valid)
    }

    fn _check_add_sub_proof_request_params_consistency(sub_proof_request: &SubProofRequest,
                                                       cred_schema: &CredentialSchema) -> IndyCryptoResult<()> {
        trace!("ProofVerifier::_check_add_sub_proof_request_params_consistency: >>> sub_proof_request: {:?}, cred_schema: {:?}", sub_proof_request, cred_schema);

        if sub_proof_request.revealed_attrs.difference(&cred_schema.attrs).count() != 0 {
            return Err(err_msg(IndyCryptoErrorKind::InvalidStructure, "Credential doesn't contain requested attribute"));
        }

        let predicates_attrs =
            sub_proof_request.predicates.iter()
                .map(|predicate| predicate.attr_name.clone())
                .collect::<BTreeSet<String>>();

        if predicates_attrs.difference(&cred_schema.attrs).count() != 0 {
            return Err(err_msg(IndyCryptoErrorKind::InvalidStructure, "Credential doesn't contain attribute requested in predicate"));
        }

        trace!("ProofVerifier::_check_add_sub_proof_request_params_consistency: <<<");

        Ok(())
    }

    fn _check_verify_params_consistency(credentials: &Vec<VerifiableCredential>,
                                        proof: &Proof) -> IndyCryptoResult<()> {
        trace!("ProofVerifier::_check_verify_params_consistency: >>> credentials: {:?}, proof: {:?}", credentials, proof);

        assert_eq!(proof.proofs.len(), credentials.len()); //FIXME return error
        for idx in 0..proof.proofs.len() {
            let proof_for_credential = &proof.proofs[idx];
            let credential = &credentials[idx];

            let proof_revealed_attrs = BTreeSet::from_iter(proof_for_credential.primary_proof.eq_proof.revealed_attrs.keys().cloned());

            if proof_revealed_attrs != credential.sub_proof_request.revealed_attrs {
                return Err(err_msg(IndyCryptoErrorKind::ProofRejected, "Proof revealed attributes not correspond to requested attributes"));
            }

            let proof_predicates =
                proof_for_credential.primary_proof.ge_proofs.iter()
                    .map(|ge_proof| ge_proof.predicate.clone())
                    .collect::<BTreeSet<Predicate>>();

            if proof_predicates != credential.sub_proof_request.predicates {
                return Err(err_msg(IndyCryptoErrorKind::ProofRejected, "Proof predicates not correspond to requested predicates"));
            }
        }

        trace!("ProofVerifier::_check_verify_params_consistency: <<<");

        Ok(())
    }

    fn _verify_primary_proof(p_pub_key: &CredentialPrimaryPublicKey,
                             c_hash: &BigNumber,
                             primary_proof: &PrimaryProof,
                             cred_schema: &CredentialSchema,
                             non_cred_schema: &NonCredentialSchema,
                             sub_proof_request: &SubProofRequest) -> IndyCryptoResult<Vec<BigNumber>> {
        trace!("ProofVerifier::_verify_primary_proof: >>> p_pub_key: {:?}, c_hash: {:?}, primary_proof: {:?}, cred_schema: {:?}, sub_proof_request: {:?}",
               p_pub_key, c_hash, primary_proof, cred_schema, sub_proof_request);

        let mut t_hat: Vec<BigNumber> = ProofVerifier::_verify_equality(p_pub_key,
                                                                        &primary_proof.eq_proof,
                                                                        c_hash,
                                                                        cred_schema,
                                                                        non_cred_schema,
                                                                        sub_proof_request)?;

        for ge_proof in primary_proof.ge_proofs.iter() {
            t_hat.append(&mut ProofVerifier::_verify_ge_predicate(p_pub_key, ge_proof, c_hash)?)
        }

        trace!("ProofVerifier::_verify_primary_proof: <<< t_hat: {:?}", t_hat);

        Ok(t_hat)
    }

    fn _verify_equality(p_pub_key: &CredentialPrimaryPublicKey,
                        proof: &PrimaryEqualProof,
                        c_hash: &BigNumber,
                        cred_schema: &CredentialSchema,
                        non_cred_schema: &NonCredentialSchema,
                        sub_proof_request: &SubProofRequest) -> IndyCryptoResult<Vec<BigNumber>> {
        trace!("ProofVerifier::_verify_equality: >>> p_pub_key: {:?}, proof: {:?}, c_hash: {:?}, cred_schema: {:?}, sub_proof_request: {:?}",
               p_pub_key, proof, c_hash, cred_schema, sub_proof_request);


        let unrevealed_attrs = cred_schema
            .attrs
            .union(&non_cred_schema.attrs)
            .cloned()
            .collect::<BTreeSet<String>>()
            .difference(&sub_proof_request.revealed_attrs)
            .cloned()
            .collect::<HashSet<String>>();

        let t1: BigNumber = calc_teq(&p_pub_key, &proof.a_prime, &proof.e, &proof.v, &proof.m, &proof.m2, &unrevealed_attrs)?;

        let mut ctx = BigNumber::new_context()?;

        let mut rar = proof.a_prime.mod_exp(&LARGE_E_START_VALUE, &p_pub_key.n, Some(&mut ctx))?;

        for (attr, encoded_value) in &proof.revealed_attrs {
            let cur_r = p_pub_key.r.get(attr)
                .ok_or(err_msg(IndyCryptoErrorKind::ProofRejected, format!("Value by key '{}' not found in pk.r", attr)))?;

            rar = cur_r
                .mod_exp(encoded_value, &p_pub_key.n, Some(&mut ctx))?
                .mod_mul(&rar, &p_pub_key.n, Some(&mut ctx))?;
        }

        let t2: BigNumber = p_pub_key.z
            .mod_div(&rar, &p_pub_key.n, Some(&mut ctx))?
            .inverse(&p_pub_key.n, Some(&mut ctx))?
            .mod_exp(&c_hash, &p_pub_key.n, Some(&mut ctx))?;

        let t: BigNumber = t1.mod_mul(&t2, &p_pub_key.n, Some(&mut ctx))?;

        trace!("ProofVerifier::_verify_equality: <<< t: {:?}", t);

        Ok(vec![t])
    }

    fn _verify_ge_predicate(p_pub_key: &CredentialPrimaryPublicKey,
                            proof: &PrimaryPredicateGEProof,
                            c_hash: &BigNumber) -> IndyCryptoResult<Vec<BigNumber>> {
        trace!("ProofVerifier::_verify_ge_predicate: >>> p_pub_key: {:?}, proof: {:?}, c_hash: {:?}", p_pub_key, proof, c_hash);

        let mut ctx = BigNumber::new_context()?;

        let mut tau_list = calc_tge(&p_pub_key, &proof.u, &proof.r, &proof.mj,
                                    &proof.alpha, &proof.t)?;

        for i in 0..ITERATION {
            let cur_t = proof.t.get(&i.to_string())
                .ok_or(err_msg(IndyCryptoErrorKind::ProofRejected, format!("Value by key '{}' not found in proof.t", i)))?;

            tau_list[i] = cur_t
                .mod_exp(&c_hash, &p_pub_key.n, Some(&mut ctx))?
                .inverse(&p_pub_key.n, Some(&mut ctx))?
                .mod_mul(&tau_list[i], &p_pub_key.n, Some(&mut ctx))?;
        }

        let delta = proof.t.get("DELTA")
            .ok_or(err_msg(IndyCryptoErrorKind::ProofRejected, format!("Value by key '{}' not found in proof.t", "DELTA")))?;

        tau_list[ITERATION] = p_pub_key.z
            .mod_exp(&BigNumber::from_dec(&proof.predicate.value.to_string())?,
                &p_pub_key.n, Some(&mut ctx))?
            .mul(&delta, Some(&mut ctx))?
            .mod_exp(&c_hash, &p_pub_key.n, Some(&mut ctx))?
            .inverse(&p_pub_key.n, Some(&mut ctx))?
            .mod_mul(&tau_list[ITERATION], &p_pub_key.n, Some(&mut ctx))?;

        tau_list[ITERATION + 1] = delta
            .mod_exp(&c_hash, &p_pub_key.n, Some(&mut ctx))?
            .inverse(&p_pub_key.n, Some(&mut ctx))?
            .mod_mul(&tau_list[ITERATION + 1], &p_pub_key.n, Some(&mut ctx))?;

        trace!("ProofVerifier::_verify_ge_predicate: <<< tau_list: {:?},", tau_list);

        Ok(tau_list)
    }

    fn _verify_non_revocation_proof(r_pub_key: &CredentialRevocationPublicKey,
                                    rev_reg: &RevocationRegistry,
                                    rev_key_pub: &RevocationKeyPublic,
                                    c_hash: &BigNumber, proof: &NonRevocProof) -> IndyCryptoResult<NonRevocProofTauList> {
        trace!("ProofVerifier::_verify_non_revocation_proof: >>> r_pub_key: {:?}, rev_reg: {:?}, rev_key_pub: {:?}, c_hash: {:?}",
               r_pub_key, rev_reg, rev_key_pub, c_hash);

        let ch_num_z = bignum_to_group_element(&c_hash)?;

        let t_hat_expected_values = create_tau_list_expected_values(r_pub_key, rev_reg, rev_key_pub, &proof.c_list)?;
        let t_hat_calc_values = create_tau_list_values(&r_pub_key, rev_reg, &proof.x_list, &proof.c_list)?;


        let non_revoc_proof_tau_list = Ok(NonRevocProofTauList {
            t1: t_hat_expected_values.t1.mul(&ch_num_z)?.add(&t_hat_calc_values.t1)?,
            t2: t_hat_expected_values.t2.mul(&ch_num_z)?.add(&t_hat_calc_values.t2)?,
            t3: t_hat_expected_values.t3.pow(&ch_num_z)?.mul(&t_hat_calc_values.t3)?,
            t4: t_hat_expected_values.t4.pow(&ch_num_z)?.mul(&t_hat_calc_values.t4)?,
            t5: t_hat_expected_values.t5.mul(&ch_num_z)?.add(&t_hat_calc_values.t5)?,
            t6: t_hat_expected_values.t6.mul(&ch_num_z)?.add(&t_hat_calc_values.t6)?,
            t7: t_hat_expected_values.t7.pow(&ch_num_z)?.mul(&t_hat_calc_values.t7)?,
            t8: t_hat_expected_values.t8.pow(&ch_num_z)?.mul(&t_hat_calc_values.t8)?
        });

        trace!("ProofVerifier::_verify_non_revocation_proof: <<< non_revoc_proof_tau_list: {:?}", non_revoc_proof_tau_list);

        non_revoc_proof_tau_list
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use cl::prover;
    use cl::issuer;
    use cl::helpers::MockHelper;
    use cl::prover::mocks::*;

    #[test]
    fn sub_proof_request_builder_works() {
        let mut sub_proof_request_builder = Verifier::new_sub_proof_request_builder().unwrap();
        sub_proof_request_builder.add_revealed_attr("name").unwrap();
        sub_proof_request_builder.add_predicate("age", "GE", 18).unwrap();
        let sub_proof_request = sub_proof_request_builder.finalize().unwrap();

        assert!(sub_proof_request.revealed_attrs.contains("name"));
        assert!(sub_proof_request.predicates.contains(&predicate()));
    }

    #[test]
    fn verify_equality_works() {
        MockHelper::inject();

        let proof = prover::mocks::eq_proof();
        let pk = issuer::mocks::credential_primary_public_key();
        let c_h = prover::mocks::aggregated_proof().c_hash;
        let credential_schema = issuer::mocks::credential_schema();
        let non_credential_schema = issuer::mocks::non_credential_schema();

        let mut sub_proof_request_builder = SubProofRequestBuilder::new().unwrap();
        sub_proof_request_builder.add_revealed_attr("name").unwrap();
        let sub_proof_request = sub_proof_request_builder.finalize().unwrap();

        let res: Vec<BigNumber> = ProofVerifier::_verify_equality(&pk,
                                                                  &proof,
                                                                  &c_h,
                                                                  &credential_schema,
                                                                  &non_credential_schema,
                                                                  &sub_proof_request).unwrap();

        assert_eq!("10403187904873314760355557832761590691431383521745031865309573910963034393207684\
        41047372720051528347747837647360259125725910627967862485202935551931564829193622679374932738\
        38474536597850351434049013891806846939373481702013509894344027659392557687896251802916259781\
        84555673228742169810564578048461551461925810052930346018787363753466820600660809185539201223\
        71561407375323615559370420617674817058682033406887804922024342182995444044012636448897449995\
        96623718830501291018016504024850859488898905605533676936340030965601041522317339491952524844\
        02507347769428679283112853202405399796966635008669186194259851326316679551259", res[0].to_dec().unwrap());
    }

    #[test]
    fn _verify_ge_predicate_works() {
        MockHelper::inject();

        let proof = prover::mocks::ge_proof();
        let c_h = prover::mocks::aggregated_proof().c_hash;
        let pk = issuer::mocks::credential_primary_public_key();

        let res = ProofVerifier::_verify_ge_predicate(&pk, &proof, &c_h);

        assert!(res.is_ok());
        let res_data = res.unwrap();

        assert_eq!("84541983257221862363846490076513159323178083291858042421207690118109227097470776\
        29156584847233795772635909150135300090254032895037949890518860393886507672431721432085454991\
        53093207263594616249619617338381693555232209880961750666056680810026822527599168269456730020\
        01231825064670095844788135102734720995698848664953286323041296412437988472201525915887801570\
        70103470323302606738147041031249783093273756323937754190996658020897337906239502331775611703\
        28042970307095658890209337238786401127759306357959942690001365403300148843097814151882478353\
        39418932462384016593481929101948092657508460688911105398322543841514412679282", res_data[0].to_dec().unwrap());

        assert_eq!("84541983257221862363846490076513159323178083291858042421207690118109227097470776\
        29156584847233795772635909150135300090254032895037949890518860393886507672431721432085454991\
        53093207263594616249619617338381693555232209880961750666056680810026822527599168269456730020\
        01231825064670095844788135102734720995698848664953286323041296412437988472201525915887801570\
        70103470323302606738147041031249783093273756323937754190996658020897337906239502331775611703\
        28042970307095658890209337238786401127759306357959942690001365403300148843097814151882478353\
        39418932462384016593481929101948092657508460688911105398322543841514412679282", res_data[4].to_dec().unwrap());

        assert_eq!("71576740094469616050175125038612941221466947853166771156257978699698137573095744\
        20081189100581220746619329202518959516574932458476055705176224361367551303754232635252988973\
        23789904575729089031680343784068658206913548928748946934732765157510452464211110112604384315\
        16865750528792129415255282372242857723274819466930397323134722222564785435619193280367926994\
        59191029832881324878202293930994818463297709055310139101500199217390179488337854210925404890\
        00403016403129020563799240705009712476150627783447048219852434435047969447195784507059403459\
        40533745092900800249667587825786217899894277583562804465078452786585349967293", res_data[5].to_dec().unwrap());
    }
}