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
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
// Bitcoin Dev Kit
// Written in 2020 by Alekos Filini <alekos.filini@gmail.com>
//
// Copyright (c) 2020-2021 Bitcoin Dev Kit Developers
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Generalized signers
//!
//! This module provides the ability to add customized signers to a [`Wallet`](super::Wallet)
//! through the [`Wallet::add_signer`](super::Wallet::add_signer) function.
//!
//! ```
//! # use alloc::sync::Arc;
//! # use core::str::FromStr;
//! # use bitcoin::secp256k1::{Secp256k1, All};
//! # use bitcoin::*;
//! # use bdk_wallet::signer::*;
//! # use bdk_wallet::*;
//! # #[derive(Debug)]
//! # struct CustomHSM;
//! # impl CustomHSM {
//! #     fn hsm_sign_input(&self, _psbt: &mut Psbt, _input: usize) -> Result<(), SignerError> {
//! #         Ok(())
//! #     }
//! #     fn connect() -> Self {
//! #         CustomHSM
//! #     }
//! #     fn get_id(&self) -> SignerId {
//! #         SignerId::Dummy(0)
//! #     }
//! # }
//! #[derive(Debug)]
//! struct CustomSigner {
//!     device: CustomHSM,
//! }
//!
//! impl CustomSigner {
//!     fn connect() -> Self {
//!         CustomSigner { device: CustomHSM::connect() }
//!     }
//! }
//!
//! impl SignerCommon for CustomSigner {
//!     fn id(&self, _secp: &Secp256k1<All>) -> SignerId {
//!         self.device.get_id()
//!     }
//! }
//!
//! impl InputSigner for CustomSigner {
//!     fn sign_input(
//!         &self,
//!         psbt: &mut Psbt,
//!         input_index: usize,
//!         _sign_options: &SignOptions,
//!         _secp: &Secp256k1<All>,
//!     ) -> Result<(), SignerError> {
//!         self.device.hsm_sign_input(psbt, input_index)?;
//!
//!         Ok(())
//!     }
//! }
//!
//! let custom_signer = CustomSigner::connect();
//!
//! let descriptor = "wpkh(tpubD6NzVbkrYhZ4Xferm7Pz4VnjdcDPFyjVu5K4iZXQ4pVN8Cks4pHVowTBXBKRhX64pkRyJZJN5xAKj4UDNnLPb5p2sSKXhewoYx5GbTdUFWq/0/*)";
//! let change_descriptor = "wpkh(tpubD6NzVbkrYhZ4Xferm7Pz4VnjdcDPFyjVu5K4iZXQ4pVN8Cks4pHVowTBXBKRhX64pkRyJZJN5xAKj4UDNnLPb5p2sSKXhewoYx5GbTdUFWq/1/*)";
//! let mut wallet = Wallet::new(descriptor, change_descriptor, Network::Testnet)?;
//! wallet.add_signer(
//!     KeychainKind::External,
//!     SignerOrdering(200),
//!     Arc::new(custom_signer)
//! );
//!
//! # Ok::<_, anyhow::Error>(())
//! ```

use crate::collections::BTreeMap;
use alloc::string::String;
use alloc::sync::Arc;
use alloc::vec::Vec;
use core::cmp::Ordering;
use core::fmt;
use core::ops::{Bound::Included, Deref};

use bitcoin::bip32::{ChildNumber, DerivationPath, Fingerprint, Xpriv};
use bitcoin::hashes::hash160;
use bitcoin::secp256k1::Message;
use bitcoin::sighash::{EcdsaSighashType, TapSighash, TapSighashType};
use bitcoin::{ecdsa, psbt, sighash, taproot, transaction};
use bitcoin::{key::TapTweak, key::XOnlyPublicKey, secp256k1};
use bitcoin::{PrivateKey, Psbt, PublicKey};

use miniscript::descriptor::{
    Descriptor, DescriptorMultiXKey, DescriptorPublicKey, DescriptorSecretKey, DescriptorXKey,
    InnerXKey, KeyMap, SinglePriv, SinglePubKey,
};
use miniscript::{Legacy, Segwitv0, SigType, Tap, ToPublicKey};

use super::utils::SecpCtx;
use crate::descriptor::{DescriptorMeta, XKeyUtils};
use crate::psbt::PsbtUtils;
use crate::wallet::error::MiniscriptPsbtError;

/// Identifier of a signer in the `SignersContainers`. Used as a key to find the right signer among
/// multiple of them
#[derive(Debug, Clone, Ord, PartialOrd, PartialEq, Eq, Hash)]
pub enum SignerId {
    /// Bitcoin HASH160 (RIPEMD160 after SHA256) hash of an ECDSA public key
    PkHash(hash160::Hash),
    /// The fingerprint of a BIP32 extended key
    Fingerprint(Fingerprint),
    /// Dummy identifier
    Dummy(u64),
}

impl From<hash160::Hash> for SignerId {
    fn from(hash: hash160::Hash) -> SignerId {
        SignerId::PkHash(hash)
    }
}

impl From<Fingerprint> for SignerId {
    fn from(fing: Fingerprint) -> SignerId {
        SignerId::Fingerprint(fing)
    }
}

/// Signing error
#[derive(Debug)]
pub enum SignerError {
    /// The private key is missing for the required public key
    MissingKey,
    /// The private key in use has the right fingerprint but derives differently than expected
    InvalidKey,
    /// The user canceled the operation
    UserCanceled,
    /// Input index is out of range
    InputIndexOutOfRange,
    /// The `non_witness_utxo` field of the transaction is required to sign this input
    MissingNonWitnessUtxo,
    /// The `non_witness_utxo` specified is invalid
    InvalidNonWitnessUtxo,
    /// The `witness_utxo` field of the transaction is required to sign this input
    MissingWitnessUtxo,
    /// The `witness_script` field of the transaction is required to sign this input
    MissingWitnessScript,
    /// The fingerprint and derivation path are missing from the psbt input
    MissingHdKeypath,
    /// The psbt contains a non-`SIGHASH_ALL` sighash in one of its input and the user hasn't
    /// explicitly allowed them
    ///
    /// To enable signing transactions with non-standard sighashes set
    /// [`SignOptions::allow_all_sighashes`] to `true`.
    NonStandardSighash,
    /// Invalid SIGHASH for the signing context in use
    InvalidSighash,
    /// Error while computing the hash to sign a P2WPKH input.
    SighashP2wpkh(sighash::P2wpkhError),
    /// Error while computing the hash to sign a Taproot input.
    SighashTaproot(sighash::TaprootError),
    /// Error while computing the hash, out of bounds access on the transaction inputs.
    TxInputsIndexError(transaction::InputsIndexError),
    /// Miniscript PSBT error
    MiniscriptPsbt(MiniscriptPsbtError),
    /// To be used only by external libraries implementing [`InputSigner`] or
    /// [`TransactionSigner`], so that they can return their own custom errors, without having to
    /// modify [`SignerError`] in BDK.
    External(String),
}

impl From<transaction::InputsIndexError> for SignerError {
    fn from(v: transaction::InputsIndexError) -> Self {
        Self::TxInputsIndexError(v)
    }
}

impl From<sighash::P2wpkhError> for SignerError {
    fn from(e: sighash::P2wpkhError) -> Self {
        Self::SighashP2wpkh(e)
    }
}

impl From<sighash::TaprootError> for SignerError {
    fn from(e: sighash::TaprootError) -> Self {
        Self::SighashTaproot(e)
    }
}

impl fmt::Display for SignerError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::MissingKey => write!(f, "Missing private key"),
            Self::InvalidKey => write!(f, "The private key in use has the right fingerprint but derives differently than expected"),
            Self::UserCanceled => write!(f, "The user canceled the operation"),
            Self::InputIndexOutOfRange => write!(f, "Input index out of range"),
            Self::MissingNonWitnessUtxo => write!(f, "Missing non-witness UTXO"),
            Self::InvalidNonWitnessUtxo => write!(f, "Invalid non-witness UTXO"),
            Self::MissingWitnessUtxo => write!(f, "Missing witness UTXO"),
            Self::MissingWitnessScript => write!(f, "Missing witness script"),
            Self::MissingHdKeypath => write!(f, "Missing fingerprint and derivation path"),
            Self::NonStandardSighash => write!(f, "The psbt contains a non standard sighash"),
            Self::InvalidSighash => write!(f, "Invalid SIGHASH for the signing context in use"),
            Self::SighashP2wpkh(err) => write!(f, "Error while computing the hash to sign a P2WPKH input: {}", err),
            Self::SighashTaproot(err) => write!(f, "Error while computing the hash to sign a Taproot input: {}", err),
            Self::TxInputsIndexError(err) => write!(f, "Error while computing the hash, out of bounds access on the transaction inputs: {}", err),
            Self::MiniscriptPsbt(err) => write!(f, "Miniscript PSBT error: {}", err),
            Self::External(err) => write!(f, "{}", err),
        }
    }
}

#[cfg(feature = "std")]
impl std::error::Error for SignerError {}

/// Signing context
///
/// Used by our software signers to determine the type of signatures to make
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SignerContext {
    /// Legacy context
    Legacy,
    /// Segwit v0 context (BIP 143)
    Segwitv0,
    /// Taproot context (BIP 340)
    Tap {
        /// Whether the signer can sign for the internal key or not
        is_internal_key: bool,
    },
}

/// Wrapper to pair a signer with its context
#[derive(Debug, Clone)]
pub struct SignerWrapper<S: Sized + fmt::Debug + Clone> {
    signer: S,
    ctx: SignerContext,
}

impl<S: Sized + fmt::Debug + Clone> SignerWrapper<S> {
    /// Create a wrapped signer from a signer and a context
    pub fn new(signer: S, ctx: SignerContext) -> Self {
        SignerWrapper { signer, ctx }
    }
}

impl<S: Sized + fmt::Debug + Clone> Deref for SignerWrapper<S> {
    type Target = S;

    fn deref(&self) -> &Self::Target {
        &self.signer
    }
}

/// Common signer methods
pub trait SignerCommon: fmt::Debug + Send + Sync {
    /// Return the [`SignerId`] for this signer
    ///
    /// The [`SignerId`] can be used to lookup a signer in the [`Wallet`](crate::Wallet)'s signers map or to
    /// compare two signers.
    fn id(&self, secp: &SecpCtx) -> SignerId;

    /// Return the secret key for the signer
    ///
    /// This is used internally to reconstruct the original descriptor that may contain secrets.
    /// External signers that are meant to keep key isolated should just return `None` here (which
    /// is the default for this method, if not overridden).
    fn descriptor_secret_key(&self) -> Option<DescriptorSecretKey> {
        None
    }
}

/// PSBT Input signer
///
/// This trait can be implemented to provide custom signers to the wallet. If the signer supports signing
/// individual inputs, this trait should be implemented and BDK will provide automatically an implementation
/// for [`TransactionSigner`].
pub trait InputSigner: SignerCommon {
    /// Sign a single psbt input
    fn sign_input(
        &self,
        psbt: &mut Psbt,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError>;
}

/// PSBT signer
///
/// This trait can be implemented when the signer can't sign inputs individually, but signs the whole transaction
/// at once.
pub trait TransactionSigner: SignerCommon {
    /// Sign all the inputs of the psbt
    fn sign_transaction(
        &self,
        psbt: &mut Psbt,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError>;
}

impl<T: InputSigner> TransactionSigner for T {
    fn sign_transaction(
        &self,
        psbt: &mut Psbt,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError> {
        for input_index in 0..psbt.inputs.len() {
            self.sign_input(psbt, input_index, sign_options, secp)?;
        }

        Ok(())
    }
}

impl SignerCommon for SignerWrapper<DescriptorXKey<Xpriv>> {
    fn id(&self, secp: &SecpCtx) -> SignerId {
        SignerId::from(self.root_fingerprint(secp))
    }

    fn descriptor_secret_key(&self) -> Option<DescriptorSecretKey> {
        Some(DescriptorSecretKey::XPrv(self.signer.clone()))
    }
}

impl InputSigner for SignerWrapper<DescriptorXKey<Xpriv>> {
    fn sign_input(
        &self,
        psbt: &mut Psbt,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError> {
        if input_index >= psbt.inputs.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }

        if psbt.inputs[input_index].final_script_sig.is_some()
            || psbt.inputs[input_index].final_script_witness.is_some()
        {
            return Ok(());
        }

        let tap_key_origins = psbt.inputs[input_index]
            .tap_key_origins
            .iter()
            .map(|(pk, (_, keysource))| (SinglePubKey::XOnly(*pk), keysource));
        let (public_key, full_path) = match psbt.inputs[input_index]
            .bip32_derivation
            .iter()
            .map(|(pk, keysource)| (SinglePubKey::FullKey(PublicKey::new(*pk)), keysource))
            .chain(tap_key_origins)
            .find_map(|(pk, keysource)| {
                if self.matches(keysource, secp).is_some() {
                    Some((pk, keysource.1.clone()))
                } else {
                    None
                }
            }) {
            Some((pk, full_path)) => (pk, full_path),
            None => return Ok(()),
        };

        let derived_key = match self.origin.clone() {
            Some((_fingerprint, origin_path)) => {
                let deriv_path = DerivationPath::from(
                    &full_path.into_iter().cloned().collect::<Vec<ChildNumber>>()
                        [origin_path.len()..],
                );
                self.xkey.derive_priv(secp, &deriv_path).unwrap()
            }
            None => self.xkey.derive_priv(secp, &full_path).unwrap(),
        };

        let computed_pk = secp256k1::PublicKey::from_secret_key(secp, &derived_key.private_key);
        let valid_key = match public_key {
            SinglePubKey::FullKey(pk) if pk.inner == computed_pk => true,
            SinglePubKey::XOnly(x_only) if XOnlyPublicKey::from(computed_pk) == x_only => true,
            _ => false,
        };
        if !valid_key {
            Err(SignerError::InvalidKey)
        } else {
            // HD wallets imply compressed keys
            let priv_key = PrivateKey {
                compressed: true,
                network: self.xkey.network,
                inner: derived_key.private_key,
            };

            SignerWrapper::new(priv_key, self.ctx).sign_input(psbt, input_index, sign_options, secp)
        }
    }
}

fn multikey_to_xkeys<K: InnerXKey + Clone>(
    multikey: DescriptorMultiXKey<K>,
) -> Vec<DescriptorXKey<K>> {
    multikey
        .derivation_paths
        .into_paths()
        .into_iter()
        .map(|derivation_path| DescriptorXKey {
            origin: multikey.origin.clone(),
            xkey: multikey.xkey.clone(),
            derivation_path,
            wildcard: multikey.wildcard,
        })
        .collect()
}

impl SignerCommon for SignerWrapper<DescriptorMultiXKey<Xpriv>> {
    fn id(&self, secp: &SecpCtx) -> SignerId {
        SignerId::from(self.root_fingerprint(secp))
    }

    fn descriptor_secret_key(&self) -> Option<DescriptorSecretKey> {
        Some(DescriptorSecretKey::MultiXPrv(self.signer.clone()))
    }
}

impl InputSigner for SignerWrapper<DescriptorMultiXKey<Xpriv>> {
    fn sign_input(
        &self,
        psbt: &mut Psbt,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError> {
        let xkeys = multikey_to_xkeys(self.signer.clone());
        for xkey in xkeys {
            SignerWrapper::new(xkey, self.ctx).sign_input(psbt, input_index, sign_options, secp)?
        }
        Ok(())
    }
}

impl SignerCommon for SignerWrapper<PrivateKey> {
    fn id(&self, secp: &SecpCtx) -> SignerId {
        SignerId::from(self.public_key(secp).to_pubkeyhash(SigType::Ecdsa))
    }

    fn descriptor_secret_key(&self) -> Option<DescriptorSecretKey> {
        Some(DescriptorSecretKey::Single(SinglePriv {
            key: self.signer,
            origin: None,
        }))
    }
}

impl InputSigner for SignerWrapper<PrivateKey> {
    fn sign_input(
        &self,
        psbt: &mut Psbt,
        input_index: usize,
        sign_options: &SignOptions,
        secp: &SecpCtx,
    ) -> Result<(), SignerError> {
        if input_index >= psbt.inputs.len() || input_index >= psbt.unsigned_tx.input.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }

        if psbt.inputs[input_index].final_script_sig.is_some()
            || psbt.inputs[input_index].final_script_witness.is_some()
        {
            return Ok(());
        }

        let pubkey = PublicKey::from_private_key(secp, self);
        let x_only_pubkey = XOnlyPublicKey::from(pubkey.inner);

        if let SignerContext::Tap { is_internal_key } = self.ctx {
            if let Some(psbt_internal_key) = psbt.inputs[input_index].tap_internal_key {
                if is_internal_key
                    && psbt.inputs[input_index].tap_key_sig.is_none()
                    && sign_options.sign_with_tap_internal_key
                    && x_only_pubkey == psbt_internal_key
                {
                    let (hash, hash_ty) = Tap::sighash(psbt, input_index, None)?;
                    sign_psbt_schnorr(
                        &self.inner,
                        x_only_pubkey,
                        None,
                        &mut psbt.inputs[input_index],
                        hash,
                        hash_ty,
                        secp,
                    );
                }
            }

            if let Some((leaf_hashes, _)) =
                psbt.inputs[input_index].tap_key_origins.get(&x_only_pubkey)
            {
                let leaf_hashes = leaf_hashes
                    .iter()
                    .filter(|lh| {
                        // Removing the leaves we shouldn't sign for
                        let should_sign = match &sign_options.tap_leaves_options {
                            TapLeavesOptions::All => true,
                            TapLeavesOptions::Include(v) => v.contains(lh),
                            TapLeavesOptions::Exclude(v) => !v.contains(lh),
                            TapLeavesOptions::None => false,
                        };
                        // Filtering out the leaves without our key
                        should_sign
                            && !psbt.inputs[input_index]
                                .tap_script_sigs
                                .contains_key(&(x_only_pubkey, **lh))
                    })
                    .cloned()
                    .collect::<Vec<_>>();
                for lh in leaf_hashes {
                    let (hash, hash_ty) = Tap::sighash(psbt, input_index, Some(lh))?;
                    sign_psbt_schnorr(
                        &self.inner,
                        x_only_pubkey,
                        Some(lh),
                        &mut psbt.inputs[input_index],
                        hash,
                        hash_ty,
                        secp,
                    );
                }
            }

            return Ok(());
        }

        if psbt.inputs[input_index].partial_sigs.contains_key(&pubkey) {
            return Ok(());
        }

        let (hash, hash_ty) = match self.ctx {
            SignerContext::Segwitv0 => {
                let (h, t) = Segwitv0::sighash(psbt, input_index, ())?;
                let h = h.to_raw_hash();
                (h, t)
            }
            SignerContext::Legacy => {
                let (h, t) = Legacy::sighash(psbt, input_index, ())?;
                let h = h.to_raw_hash();
                (h, t)
            }
            _ => return Ok(()), // handled above
        };
        sign_psbt_ecdsa(
            &self.inner,
            pubkey,
            &mut psbt.inputs[input_index],
            hash,
            hash_ty,
            secp,
            sign_options.allow_grinding,
        );

        Ok(())
    }
}

fn sign_psbt_ecdsa(
    secret_key: &secp256k1::SecretKey,
    pubkey: PublicKey,
    psbt_input: &mut psbt::Input,
    hash: impl bitcoin::hashes::Hash<Bytes = [u8; 32]>,
    sighash_type: EcdsaSighashType,
    secp: &SecpCtx,
    allow_grinding: bool,
) {
    let msg = &Message::from_digest(hash.to_byte_array());
    let signature = if allow_grinding {
        secp.sign_ecdsa_low_r(msg, secret_key)
    } else {
        secp.sign_ecdsa(msg, secret_key)
    };
    secp.verify_ecdsa(msg, &signature, &pubkey.inner)
        .expect("invalid or corrupted ecdsa signature");

    let final_signature = ecdsa::Signature {
        signature,
        sighash_type,
    };
    psbt_input.partial_sigs.insert(pubkey, final_signature);
}

// Calling this with `leaf_hash` = `None` will sign for key-spend
fn sign_psbt_schnorr(
    secret_key: &secp256k1::SecretKey,
    pubkey: XOnlyPublicKey,
    leaf_hash: Option<taproot::TapLeafHash>,
    psbt_input: &mut psbt::Input,
    hash: TapSighash,
    sighash_type: TapSighashType,
    secp: &SecpCtx,
) {
    let keypair = secp256k1::Keypair::from_seckey_slice(secp, secret_key.as_ref()).unwrap();
    let keypair = match leaf_hash {
        None => keypair
            .tap_tweak(secp, psbt_input.tap_merkle_root)
            .to_inner(),
        Some(_) => keypair, // no tweak for script spend
    };

    let msg = &Message::from(hash);
    let signature = secp.sign_schnorr(msg, &keypair);
    secp.verify_schnorr(&signature, msg, &XOnlyPublicKey::from_keypair(&keypair).0)
        .expect("invalid or corrupted schnorr signature");

    let final_signature = taproot::Signature {
        signature,
        sighash_type,
    };

    if let Some(lh) = leaf_hash {
        psbt_input
            .tap_script_sigs
            .insert((pubkey, lh), final_signature);
    } else {
        psbt_input.tap_key_sig = Some(final_signature);
    }
}

/// Defines the order in which signers are called
///
/// The default value is `100`. Signers with an ordering above that will be called later,
/// and they will thus see the partial signatures added to the transaction once they get to sign
/// themselves.
#[derive(Debug, Clone, PartialOrd, PartialEq, Ord, Eq)]
pub struct SignerOrdering(pub usize);

impl Default for SignerOrdering {
    fn default() -> Self {
        SignerOrdering(100)
    }
}

#[derive(Debug, Clone)]
struct SignersContainerKey {
    id: SignerId,
    ordering: SignerOrdering,
}

impl From<(SignerId, SignerOrdering)> for SignersContainerKey {
    fn from(tuple: (SignerId, SignerOrdering)) -> Self {
        SignersContainerKey {
            id: tuple.0,
            ordering: tuple.1,
        }
    }
}

/// Container for multiple signers
#[derive(Debug, Default, Clone)]
pub struct SignersContainer(BTreeMap<SignersContainerKey, Arc<dyn TransactionSigner>>);

impl SignersContainer {
    /// Create a map of public keys to secret keys
    pub fn as_key_map(&self, secp: &SecpCtx) -> KeyMap {
        self.0
            .values()
            .filter_map(|signer| signer.descriptor_secret_key())
            .filter_map(|secret| secret.to_public(secp).ok().map(|public| (public, secret)))
            .collect()
    }

    /// Build a new signer container from a [`KeyMap`]
    ///
    /// Also looks at the corresponding descriptor to determine the [`SignerContext`] to attach to
    /// the signers
    pub fn build(
        keymap: KeyMap,
        descriptor: &Descriptor<DescriptorPublicKey>,
        secp: &SecpCtx,
    ) -> SignersContainer {
        let mut container = SignersContainer::new();

        for (pubkey, secret) in keymap {
            let ctx = match descriptor {
                Descriptor::Tr(tr) => SignerContext::Tap {
                    is_internal_key: tr.internal_key() == &pubkey,
                },
                _ if descriptor.is_witness() => SignerContext::Segwitv0,
                _ => SignerContext::Legacy,
            };

            match secret {
                DescriptorSecretKey::Single(private_key) => container.add_external(
                    SignerId::from(
                        private_key
                            .key
                            .public_key(secp)
                            .to_pubkeyhash(SigType::Ecdsa),
                    ),
                    SignerOrdering::default(),
                    Arc::new(SignerWrapper::new(private_key.key, ctx)),
                ),
                DescriptorSecretKey::XPrv(xprv) => container.add_external(
                    SignerId::from(xprv.root_fingerprint(secp)),
                    SignerOrdering::default(),
                    Arc::new(SignerWrapper::new(xprv, ctx)),
                ),
                DescriptorSecretKey::MultiXPrv(xprv) => container.add_external(
                    SignerId::from(xprv.root_fingerprint(secp)),
                    SignerOrdering::default(),
                    Arc::new(SignerWrapper::new(xprv, ctx)),
                ),
            };
        }

        container
    }
}

impl SignersContainer {
    /// Default constructor
    pub fn new() -> Self {
        SignersContainer(Default::default())
    }

    /// Adds an external signer to the container for the specified id. Optionally returns the
    /// signer that was previously in the container, if any
    pub fn add_external(
        &mut self,
        id: SignerId,
        ordering: SignerOrdering,
        signer: Arc<dyn TransactionSigner>,
    ) -> Option<Arc<dyn TransactionSigner>> {
        self.0.insert((id, ordering).into(), signer)
    }

    /// Removes a signer from the container and returns it
    pub fn remove(
        &mut self,
        id: SignerId,
        ordering: SignerOrdering,
    ) -> Option<Arc<dyn TransactionSigner>> {
        self.0.remove(&(id, ordering).into())
    }

    /// Returns the list of identifiers of all the signers in the container
    pub fn ids(&self) -> Vec<&SignerId> {
        self.0
            .keys()
            .map(|SignersContainerKey { id, .. }| id)
            .collect()
    }

    /// Returns the list of signers in the container, sorted by lowest to highest `ordering`
    pub fn signers(&self) -> Vec<&Arc<dyn TransactionSigner>> {
        self.0.values().collect()
    }

    /// Finds the signer with lowest ordering for a given id in the container.
    pub fn find(&self, id: SignerId) -> Option<&Arc<dyn TransactionSigner>> {
        self.0
            .range((
                Included(&(id.clone(), SignerOrdering(0)).into()),
                Included(&(id.clone(), SignerOrdering(usize::MAX)).into()),
            ))
            .filter(|(k, _)| k.id == id)
            .map(|(_, v)| v)
            .next()
    }
}

/// Options for a software signer
///
/// Adjust the behavior of our software signers and the way a transaction is finalized
#[derive(Debug, Clone)]
pub struct SignOptions {
    /// Whether the signer should trust the `witness_utxo`, if the `non_witness_utxo` hasn't been
    /// provided
    ///
    /// Defaults to `false` to mitigate the "SegWit bug" which should trick the wallet into
    /// paying a fee larger than expected.
    ///
    /// Some wallets, especially if relatively old, might not provide the `non_witness_utxo` for
    /// SegWit transactions in the PSBT they generate: in those cases setting this to `true`
    /// should correctly produce a signature, at the expense of an increased trust in the creator
    /// of the PSBT.
    ///
    /// For more details see: <https://blog.trezor.io/details-of-firmware-updates-for-trezor-one-version-1-9-1-and-trezor-model-t-version-2-3-1-1eba8f60f2dd>
    pub trust_witness_utxo: bool,

    /// Whether the wallet should assume a specific height has been reached when trying to finalize
    /// a transaction
    ///
    /// The wallet will only "use" a timelock to satisfy the spending policy of an input if the
    /// timelock height has already been reached. This option allows overriding the "current height" to let the
    /// wallet use timelocks in the future to spend a coin.
    pub assume_height: Option<u32>,

    /// Whether the signer should use the `sighash_type` set in the PSBT when signing, no matter
    /// what its value is
    ///
    /// Defaults to `false` which will only allow signing using `SIGHASH_ALL`.
    pub allow_all_sighashes: bool,

    /// Whether to remove partial signatures from the PSBT inputs while finalizing PSBT.
    ///
    /// Defaults to `true` which will remove partial signatures during finalization.
    pub remove_partial_sigs: bool,

    /// Whether to remove taproot specific fields from the PSBT on finalization.
    ///
    /// For inputs this includes the taproot internal key, merkle root, and individual
    /// scripts and signatures. For both inputs and outputs it includes key origin info.
    ///
    /// Defaults to `true` which will remove all of the above mentioned fields when finalizing.
    ///
    /// See [`BIP371`](https://github.com/bitcoin/bips/blob/master/bip-0371.mediawiki) for details.
    pub remove_taproot_extras: bool,

    /// Whether to try finalizing the PSBT after the inputs are signed.
    ///
    /// Defaults to `true` which will try finalizing PSBT after inputs are signed.
    pub try_finalize: bool,

    /// Specifies which Taproot script-spend leaves we should sign for. This option is
    /// ignored if we're signing a non-taproot PSBT.
    ///
    /// Defaults to All, i.e., the wallet will sign all the leaves it has a key for.
    pub tap_leaves_options: TapLeavesOptions,

    /// Whether we should try to sign a taproot transaction with the taproot internal key
    /// or not. This option is ignored if we're signing a non-taproot PSBT.
    ///
    /// Defaults to `true`, i.e., we always try to sign with the taproot internal key.
    pub sign_with_tap_internal_key: bool,

    /// Whether we should grind ECDSA signature to ensure signing with low r
    /// or not.
    /// Defaults to `true`, i.e., we always grind ECDSA signature to sign with low r.
    pub allow_grinding: bool,
}

/// Customize which taproot script-path leaves the signer should sign.
#[derive(Default, Debug, Clone, PartialEq, Eq)]
pub enum TapLeavesOptions {
    /// The signer will sign all the leaves it has a key for.
    #[default]
    All,
    /// The signer won't sign leaves other than the ones specified. Note that it could still ignore
    /// some of the specified leaves, if it doesn't have the right key to sign them.
    Include(Vec<taproot::TapLeafHash>),
    /// The signer won't sign the specified leaves.
    Exclude(Vec<taproot::TapLeafHash>),
    /// The signer won't sign any leaf.
    None,
}

impl Default for SignOptions {
    fn default() -> Self {
        SignOptions {
            trust_witness_utxo: false,
            assume_height: None,
            allow_all_sighashes: false,
            remove_partial_sigs: true,
            remove_taproot_extras: true,
            try_finalize: true,
            tap_leaves_options: TapLeavesOptions::default(),
            sign_with_tap_internal_key: true,
            allow_grinding: true,
        }
    }
}

pub(crate) trait ComputeSighash {
    type Extra;
    type Sighash;
    type SighashType;

    fn sighash(
        psbt: &Psbt,
        input_index: usize,
        extra: Self::Extra,
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError>;
}

impl ComputeSighash for Legacy {
    type Extra = ();
    type Sighash = sighash::LegacySighash;
    type SighashType = EcdsaSighashType;

    fn sighash(
        psbt: &Psbt,
        input_index: usize,
        _extra: (),
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError> {
        if input_index >= psbt.inputs.len() || input_index >= psbt.unsigned_tx.input.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }

        let psbt_input = &psbt.inputs[input_index];
        let tx_input = &psbt.unsigned_tx.input[input_index];

        let sighash = psbt_input
            .sighash_type
            .unwrap_or_else(|| EcdsaSighashType::All.into())
            .ecdsa_hash_ty()
            .map_err(|_| SignerError::InvalidSighash)?;
        let script = match psbt_input.redeem_script {
            Some(ref redeem_script) => redeem_script.clone(),
            None => {
                let non_witness_utxo = psbt_input
                    .non_witness_utxo
                    .as_ref()
                    .ok_or(SignerError::MissingNonWitnessUtxo)?;
                let prev_out = non_witness_utxo
                    .output
                    .get(tx_input.previous_output.vout as usize)
                    .ok_or(SignerError::InvalidNonWitnessUtxo)?;

                prev_out.script_pubkey.clone()
            }
        };

        Ok((
            sighash::SighashCache::new(&psbt.unsigned_tx).legacy_signature_hash(
                input_index,
                &script,
                sighash.to_u32(),
            )?,
            sighash,
        ))
    }
}

impl ComputeSighash for Segwitv0 {
    type Extra = ();
    type Sighash = sighash::SegwitV0Sighash;
    type SighashType = EcdsaSighashType;

    fn sighash(
        psbt: &Psbt,
        input_index: usize,
        _extra: (),
    ) -> Result<(Self::Sighash, Self::SighashType), SignerError> {
        if input_index >= psbt.inputs.len() || input_index >= psbt.unsigned_tx.input.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }

        let psbt_input = &psbt.inputs[input_index];
        let tx_input = &psbt.unsigned_tx.input[input_index];

        let sighash_type = psbt_input
            .sighash_type
            .unwrap_or_else(|| EcdsaSighashType::All.into())
            .ecdsa_hash_ty()
            .map_err(|_| SignerError::InvalidSighash)?;

        // Always try first with the non-witness utxo
        let utxo = if let Some(prev_tx) = &psbt_input.non_witness_utxo {
            // Check the provided prev-tx
            if prev_tx.compute_txid() != tx_input.previous_output.txid {
                return Err(SignerError::InvalidNonWitnessUtxo);
            }

            // The output should be present, if it's missing the `non_witness_utxo` is invalid
            prev_tx
                .output
                .get(tx_input.previous_output.vout as usize)
                .ok_or(SignerError::InvalidNonWitnessUtxo)?
        } else if let Some(witness_utxo) = &psbt_input.witness_utxo {
            // Fallback to the witness_utxo. If we aren't allowed to use it, signing should fail
            // before we get to this point
            witness_utxo
        } else {
            // Nothing has been provided
            return Err(SignerError::MissingNonWitnessUtxo);
        };
        let value = utxo.value;

        let mut sighasher = sighash::SighashCache::new(&psbt.unsigned_tx);

        let sighash = match psbt_input.witness_script {
            Some(ref witness_script) => {
                sighasher.p2wsh_signature_hash(input_index, witness_script, value, sighash_type)?
            }
            None => {
                if utxo.script_pubkey.is_p2wpkh() {
                    sighasher.p2wpkh_signature_hash(
                        input_index,
                        &utxo.script_pubkey,
                        value,
                        sighash_type,
                    )?
                } else if psbt_input
                    .redeem_script
                    .as_ref()
                    .map(|s| s.is_p2wpkh())
                    .unwrap_or(false)
                {
                    let script_pubkey = psbt_input.redeem_script.as_ref().unwrap();
                    sighasher.p2wpkh_signature_hash(
                        input_index,
                        script_pubkey,
                        value,
                        sighash_type,
                    )?
                } else {
                    return Err(SignerError::MissingWitnessScript);
                }
            }
        };
        Ok((sighash, sighash_type))
    }
}

impl ComputeSighash for Tap {
    type Extra = Option<taproot::TapLeafHash>;
    type Sighash = TapSighash;
    type SighashType = TapSighashType;

    fn sighash(
        psbt: &Psbt,
        input_index: usize,
        extra: Self::Extra,
    ) -> Result<(Self::Sighash, TapSighashType), SignerError> {
        if input_index >= psbt.inputs.len() || input_index >= psbt.unsigned_tx.input.len() {
            return Err(SignerError::InputIndexOutOfRange);
        }

        let psbt_input = &psbt.inputs[input_index];

        let sighash_type = psbt_input
            .sighash_type
            .unwrap_or_else(|| TapSighashType::Default.into())
            .taproot_hash_ty()
            .map_err(|_| SignerError::InvalidSighash)?;
        let witness_utxos = (0..psbt.inputs.len())
            .map(|i| psbt.get_utxo_for(i))
            .collect::<Vec<_>>();
        let mut all_witness_utxos = vec![];

        let mut cache = sighash::SighashCache::new(&psbt.unsigned_tx);
        let is_anyone_can_pay = psbt::PsbtSighashType::from(sighash_type).to_u32() & 0x80 != 0;
        let prevouts = if is_anyone_can_pay {
            sighash::Prevouts::One(
                input_index,
                witness_utxos[input_index]
                    .as_ref()
                    .ok_or(SignerError::MissingWitnessUtxo)?,
            )
        } else if witness_utxos.iter().all(Option::is_some) {
            all_witness_utxos.extend(witness_utxos.iter().filter_map(|x| x.as_ref()));
            sighash::Prevouts::All(&all_witness_utxos)
        } else {
            return Err(SignerError::MissingWitnessUtxo);
        };

        // Assume no OP_CODESEPARATOR
        let extra = extra.map(|leaf_hash| (leaf_hash, 0xFFFFFFFF));

        Ok((
            cache.taproot_signature_hash(input_index, &prevouts, None, extra, sighash_type)?,
            sighash_type,
        ))
    }
}

impl PartialOrd for SignersContainerKey {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for SignersContainerKey {
    fn cmp(&self, other: &Self) -> Ordering {
        self.ordering
            .cmp(&other.ordering)
            .then(self.id.cmp(&other.id))
    }
}

impl PartialEq for SignersContainerKey {
    fn eq(&self, other: &Self) -> bool {
        self.id == other.id && self.ordering == other.ordering
    }
}

impl Eq for SignersContainerKey {}

#[cfg(test)]
mod signers_container_tests {
    use super::*;
    use crate::descriptor;
    use crate::descriptor::IntoWalletDescriptor;
    use crate::keys::{DescriptorKey, IntoDescriptorKey};
    use assert_matches::assert_matches;
    use bitcoin::bip32;
    use bitcoin::secp256k1::{All, Secp256k1};
    use bitcoin::Network;
    use core::str::FromStr;
    use miniscript::ScriptContext;

    fn is_equal(this: &Arc<dyn TransactionSigner>, that: &Arc<DummySigner>) -> bool {
        let secp = Secp256k1::new();
        this.id(&secp) == that.id(&secp)
    }

    // Signers added with the same ordering (like `Ordering::default`) created from `KeyMap`
    // should be preserved and not overwritten.
    // This happens usually when a set of signers is created from a descriptor with private keys.
    #[test]
    fn signers_with_same_ordering() {
        let secp = Secp256k1::new();

        let (prvkey1, _, _) = setup_keys(TPRV0_STR);
        let (prvkey2, _, _) = setup_keys(TPRV1_STR);
        let desc = descriptor!(sh(multi(2, prvkey1, prvkey2))).unwrap();
        let (wallet_desc, keymap) = desc
            .into_wallet_descriptor(&secp, Network::Testnet)
            .unwrap();

        let signers = SignersContainer::build(keymap, &wallet_desc, &secp);
        assert_eq!(signers.ids().len(), 2);

        let signers = signers.signers();
        assert_eq!(signers.len(), 2);
    }

    #[test]
    fn signers_sorted_by_ordering() {
        let mut signers = SignersContainer::new();
        let signer1 = Arc::new(DummySigner { number: 1 });
        let signer2 = Arc::new(DummySigner { number: 2 });
        let signer3 = Arc::new(DummySigner { number: 3 });

        // Mixed order insertions verifies we are not inserting at head or tail.
        signers.add_external(SignerId::Dummy(2), SignerOrdering(2), signer2.clone());
        signers.add_external(SignerId::Dummy(1), SignerOrdering(1), signer1.clone());
        signers.add_external(SignerId::Dummy(3), SignerOrdering(3), signer3.clone());

        // Check that signers are sorted from lowest to highest ordering
        let signers = signers.signers();

        assert!(is_equal(signers[0], &signer1));
        assert!(is_equal(signers[1], &signer2));
        assert!(is_equal(signers[2], &signer3));
    }

    #[test]
    fn find_signer_by_id() {
        let mut signers = SignersContainer::new();
        let signer1 = Arc::new(DummySigner { number: 1 });
        let signer2 = Arc::new(DummySigner { number: 2 });
        let signer3 = Arc::new(DummySigner { number: 3 });
        let signer4 = Arc::new(DummySigner { number: 3 }); // Same ID as `signer3` but will use lower ordering.

        let id1 = SignerId::Dummy(1);
        let id2 = SignerId::Dummy(2);
        let id3 = SignerId::Dummy(3);
        let id_nonexistent = SignerId::Dummy(999);

        signers.add_external(id1.clone(), SignerOrdering(1), signer1.clone());
        signers.add_external(id2.clone(), SignerOrdering(2), signer2.clone());
        signers.add_external(id3.clone(), SignerOrdering(3), signer3.clone());

        assert_matches!(signers.find(id1), Some(signer) if is_equal(signer, &signer1));
        assert_matches!(signers.find(id2), Some(signer) if is_equal(signer, &signer2));
        assert_matches!(signers.find(id3.clone()), Some(signer) if is_equal(signer, &signer3));

        // The `signer4` has the same ID as `signer3` but lower ordering.
        // It should be found by `id3` instead of `signer3`.
        signers.add_external(id3.clone(), SignerOrdering(2), signer4.clone());
        assert_matches!(signers.find(id3), Some(signer) if is_equal(signer, &signer4));

        // Can't find anything with ID that doesn't exist
        assert_matches!(signers.find(id_nonexistent), None);
    }

    #[derive(Debug, Clone, Copy)]
    struct DummySigner {
        number: u64,
    }

    impl SignerCommon for DummySigner {
        fn id(&self, _secp: &SecpCtx) -> SignerId {
            SignerId::Dummy(self.number)
        }
    }

    impl TransactionSigner for DummySigner {
        fn sign_transaction(
            &self,
            _psbt: &mut Psbt,
            _sign_options: &SignOptions,
            _secp: &SecpCtx,
        ) -> Result<(), SignerError> {
            Ok(())
        }
    }

    const TPRV0_STR:&str = "tprv8ZgxMBicQKsPdZXrcHNLf5JAJWFAoJ2TrstMRdSKtEggz6PddbuSkvHKM9oKJyFgZV1B7rw8oChspxyYbtmEXYyg1AjfWbL3ho3XHDpHRZf";
    const TPRV1_STR:&str = "tprv8ZgxMBicQKsPdpkqS7Eair4YxjcuuvDPNYmKX3sCniCf16tHEVrjjiSXEkFRnUH77yXc6ZcwHHcLNfjdi5qUvw3VDfgYiH5mNsj5izuiu2N";

    const PATH: &str = "m/44'/1'/0'/0";

    fn setup_keys<Ctx: ScriptContext>(
        tprv: &str,
    ) -> (DescriptorKey<Ctx>, DescriptorKey<Ctx>, Fingerprint) {
        let secp: Secp256k1<All> = Secp256k1::new();
        let path = bip32::DerivationPath::from_str(PATH).unwrap();
        let tprv = bip32::Xpriv::from_str(tprv).unwrap();
        let tpub = bip32::Xpub::from_priv(&secp, &tprv);
        let fingerprint = tprv.fingerprint(&secp);
        let prvkey = (tprv, path.clone()).into_descriptor_key().unwrap();
        let pubkey = (tpub, path).into_descriptor_key().unwrap();

        (prvkey, pubkey, fingerprint)
    }
}