Add methods to Descriptor + DescriptorPublicKey

bdk-ffi/src/bdk.udl

@@ -169,6 +169,47 @@ interface LoadWithPersistError {
     CouldNotLoad();
 };
 
+[Error]
+interface MiniscriptError {
+    AbsoluteLockTime();
+    AddrError(string error_message);
+    AddrP2shError(string error_message);
+    AnalysisError(string error_message);
+    AtOutsideOr();
+    BadDescriptor(string error_message);
+    BareDescriptorAddr();
+    CmsTooManyKeys(u32 keys);
+    ContextError(string error_message);
+    CouldNotSatisfy();
+    ExpectedChar(string char);
+    ImpossibleSatisfaction();
+    InvalidOpcode();
+    InvalidPush();
+    LiftError(string error_message);
+    MaxRecursiveDepthExceeded();
+    MissingSig();
+    MultiATooManyKeys(u64 keys);
+    MultiColon();
+    MultipathDescLenMismatch();
+    NonMinimalVerify(string error_message);
+    NonStandardBareScript();
+    NonTopLevel(string error_message);
+    ParseThreshold();
+    PolicyError(string error_message);
+    PubKeyCtxError();
+    RelativeLockTime();
+    Script(string error_message);
+    Secp(string error_message);
+    Threshold();
+    TrNoScriptCode();
+    Trailing(string error_message);
+    TypeCheck(string error_message);
+    Unexpected(string error_message);
+    UnexpectedStart();
+    UnknownWrapper(string char);
+    Unprintable(u8 byte);
+};
+
 [Error]
 interface PersistenceError {
   Write(string error_message);
@@ -736,6 +777,12 @@ interface DescriptorPublicKey {
   DescriptorPublicKey extend([ByRef] DerivationPath path);
 
   string as_string();
+
+  /// Whether or not this key has multiple derivation paths.
+  boolean is_multipath();
+
+  /// The fingerprint of the master key associated with this key, `0x00000000` if none.
+  string master_fingerprint();
 };
 
 [Traits=(Display)]
@@ -768,6 +815,16 @@ interface Descriptor {
   constructor([ByRef] DescriptorPublicKey public_key, string fingerprint, KeychainKind keychain, Network network);
 
   string to_string_with_secret();
+
+  /// Whether or not this key has multiple derivation paths.
+  boolean is_multipath();
+
+  /// Get as many descriptors as different paths in this descriptor.
+  ///
+  /// For multipath descriptors it will return as many descriptors as there is
+  /// "parallel" paths. For regular descriptors it will just return itself.
+  [Throws=MiniscriptError]
+  sequence<Descriptor> to_single_descriptors();
 };
 
 // ------------------------------------------------------------------------

bdk-ffi/src/descriptor.rs

@@ -14,8 +14,10 @@ use bdk_wallet::template::{
 };
 use bdk_wallet::KeychainKind;
 
+use crate::error::MiniscriptError;
 use std::fmt::Display;
 use std::str::FromStr;
+use std::sync::Arc;
 
 #[derive(Debug)]
 pub struct Descriptor {
@@ -266,6 +268,28 @@ impl Descriptor {
         let key_map = &self.key_map;
         descriptor.to_string_with_secret(key_map)
     }
+
+    pub(crate) fn is_multipath(&self) -> bool {
+        self.extended_descriptor.is_multipath()
+    }
+
+    pub(crate) fn to_single_descriptors(&self) -> Result<Vec<Arc<Descriptor>>, MiniscriptError> {
+        self.extended_descriptor
+            .clone()
+            .into_single_descriptors()
+            .map_err(MiniscriptError::from)
+            .map(|descriptors| {
+                descriptors
+                    .into_iter()
+                    .map(|desc| {
+                        Arc::new(Descriptor {
+                            extended_descriptor: desc,
+                            key_map: self.key_map.clone(),
+                        })
+                    })
+                    .collect()
+            })
+    }
 }
 
 impl Display for Descriptor {

bdk-ffi/src/error.rs

@@ -409,6 +409,120 @@ pub enum LoadWithPersistError {
     CouldNotLoad,
 }
 
+#[derive(Debug, thiserror::Error)]
+pub enum MiniscriptError {
+    #[error("absolute locktime error")]
+    AbsoluteLockTime,
+
+    #[error("address error: {error_message}")]
+    AddrError { error_message: String },
+
+    #[error("p2sh address error: {error_message}")]
+    AddrP2shError { error_message: String },
+
+    #[error("analysis error: {error_message}")]
+    AnalysisError { error_message: String },
+
+    #[error("@ found outside of OR")]
+    AtOutsideOr,
+
+    #[error("bad descriptor: {error_message}")]
+    BadDescriptor { error_message: String },
+
+    #[error("bare descriptor address")]
+    BareDescriptorAddr,
+
+    #[error("too many keys in checkmultisig: {keys}")]
+    CmsTooManyKeys { keys: u32 },
+
+    #[error("context error: {error_message}")]
+    ContextError { error_message: String },
+
+    #[error("could not satisfy")]
+    CouldNotSatisfy,
+
+    #[error("expected character: {char}")]
+    ExpectedChar { char: String },
+
+    #[error("impossible satisfaction")]
+    ImpossibleSatisfaction,
+
+    #[error("invalid opcode")]
+    InvalidOpcode,
+
+    #[error("invalid push")]
+    InvalidPush,
+
+    #[error("lift error: {error_message}")]
+    LiftError { error_message: String },
+
+    #[error("maximum recursive depth exceeded")]
+    MaxRecursiveDepthExceeded,
+
+    #[error("missing signature")]
+    MissingSig,
+
+    #[error("too many keys in multi-a: {keys}")]
+    MultiATooManyKeys { keys: u64 },
+
+    #[error("multiple colons in fragment name")]
+    MultiColon,
+
+    #[error("multipath descriptor length mismatch")]
+    MultipathDescLenMismatch,
+
+    #[error("non-minimal verify: {error_message}")]
+    NonMinimalVerify { error_message: String },
+
+    #[error("non-standard bare script")]
+    NonStandardBareScript,
+
+    #[error("non top-level: {error_message}")]
+    NonTopLevel { error_message: String },
+
+    #[error("parse threshold error")]
+    ParseThreshold,
+
+    #[error("policy error: {error_message}")]
+    PolicyError { error_message: String },
+
+    #[error("pubkey context error")]
+    PubKeyCtxError,
+
+    #[error("relative locktime error")]
+    RelativeLockTime,
+
+    #[error("script error: {error_message}")]
+    Script { error_message: String },
+
+    #[error("secp256k1 error: {error_message}")]
+    Secp { error_message: String },
+
+    #[error("threshold error")]
+    Threshold,
+
+    #[error("no script code for taproot")]
+    TrNoScriptCode,
+
+    #[error("trailing data: {error_message}")]
+    Trailing { error_message: String },
+
+    #[error("type check error: {error_message}")]
+    TypeCheck { error_message: String },
+
+    #[error("unexpected: {error_message}")]
+    Unexpected { error_message: String },
+
+    #[error("unexpected start")]
+    UnexpectedStart,
+
+    #[error("unknown wrapper: {char}")]
+    UnknownWrapper { char: String },
+
+    #[error("unprintable character: {byte}")]
+    Unprintable { byte: u8 },
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum PersistenceError {
     #[error("writing to persistence error: {error_message}")]
@@ -1063,6 +1177,81 @@ impl From<BdkLoadWithPersistError<chain::rusqlite::Error>> for LoadWithPersistEr
     }
 }
 
+impl From<bdk_wallet::miniscript::Error> for MiniscriptError {
+    fn from(error: bdk_wallet::miniscript::Error) -> Self {
+        use bdk_wallet::miniscript::Error as BdkMiniscriptError;
+        match error {
+            BdkMiniscriptError::AbsoluteLockTime(_) => MiniscriptError::AbsoluteLockTime,
+            BdkMiniscriptError::AddrError(e) => MiniscriptError::AddrError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::AddrP2shError(e) => MiniscriptError::AddrP2shError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::AnalysisError(e) => MiniscriptError::AnalysisError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::AtOutsideOr(_) => MiniscriptError::AtOutsideOr,
+            BdkMiniscriptError::BadDescriptor(s) => {
+                MiniscriptError::BadDescriptor { error_message: s }
+            }
+            BdkMiniscriptError::BareDescriptorAddr => MiniscriptError::BareDescriptorAddr,
+            BdkMiniscriptError::CmsTooManyKeys(n) => MiniscriptError::CmsTooManyKeys { keys: n },
+            BdkMiniscriptError::ContextError(e) => MiniscriptError::ContextError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::CouldNotSatisfy => MiniscriptError::CouldNotSatisfy,
+            BdkMiniscriptError::ExpectedChar(c) => MiniscriptError::ExpectedChar {
+                char: c.to_string(),
+            },
+            BdkMiniscriptError::ImpossibleSatisfaction => MiniscriptError::ImpossibleSatisfaction,
+            BdkMiniscriptError::InvalidOpcode(_) => MiniscriptError::InvalidOpcode,
+            BdkMiniscriptError::InvalidPush(_) => MiniscriptError::InvalidPush,
+            BdkMiniscriptError::LiftError(e) => MiniscriptError::LiftError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::MaxRecursiveDepthExceeded => {
+                MiniscriptError::MaxRecursiveDepthExceeded
+            }
+            BdkMiniscriptError::MissingSig(_) => MiniscriptError::MissingSig,
+            BdkMiniscriptError::MultiATooManyKeys(n) => {
+                MiniscriptError::MultiATooManyKeys { keys: n }
+            }
+            BdkMiniscriptError::MultiColon(_) => MiniscriptError::MultiColon,
+            BdkMiniscriptError::MultipathDescLenMismatch => {
+                MiniscriptError::MultipathDescLenMismatch
+            }
+            BdkMiniscriptError::NonMinimalVerify(s) => {
+                MiniscriptError::NonMinimalVerify { error_message: s }
+            }
+            BdkMiniscriptError::NonStandardBareScript => MiniscriptError::NonStandardBareScript,
+            BdkMiniscriptError::NonTopLevel(s) => MiniscriptError::NonTopLevel { error_message: s },
+            BdkMiniscriptError::ParseThreshold(_) => MiniscriptError::ParseThreshold,
+            BdkMiniscriptError::PolicyError(e) => MiniscriptError::PolicyError {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::PubKeyCtxError(_, _) => MiniscriptError::PubKeyCtxError,
+            BdkMiniscriptError::RelativeLockTime(_) => MiniscriptError::RelativeLockTime,
+            BdkMiniscriptError::Script(e) => MiniscriptError::Script {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::Secp(e) => MiniscriptError::Secp {
+                error_message: e.to_string(),
+            },
+            BdkMiniscriptError::Threshold(_) => MiniscriptError::Threshold,
+            BdkMiniscriptError::TrNoScriptCode => MiniscriptError::TrNoScriptCode,
+            BdkMiniscriptError::Trailing(s) => MiniscriptError::Trailing { error_message: s },
+            BdkMiniscriptError::TypeCheck(s) => MiniscriptError::TypeCheck { error_message: s },
+            BdkMiniscriptError::Unexpected(s) => MiniscriptError::Unexpected { error_message: s },
+            BdkMiniscriptError::UnexpectedStart => MiniscriptError::UnexpectedStart,
+            BdkMiniscriptError::UnknownWrapper(c) => MiniscriptError::UnknownWrapper {
+                char: c.to_string(),
+            },
+            BdkMiniscriptError::Unprintable(b) => MiniscriptError::Unprintable { byte: b },
+        }
+    }
+}
+
 impl From<std::io::Error> for PersistenceError {
     fn from(error: std::io::Error) -> Self {
         PersistenceError::Write {

bdk-ffi/src/keys.rs

@@ -223,6 +223,14 @@ impl DescriptorPublicKey {
     pub(crate) fn as_string(&self) -> String {
         self.0.to_string()
     }
+
+    pub(crate) fn is_multipath(&self) -> bool {
+        self.0.is_multipath()
+    }
+
+    pub(crate) fn master_fingerprint(&self) -> String {
+        self.0.master_fingerprint().to_string()
+    }
 }
 
 #[cfg(test)]

bdk-ffi/src/lib.rs

@@ -30,6 +30,7 @@ use crate::error::EsploraError;
 use crate::error::ExtractTxError;
 use crate::error::FromScriptError;
 use crate::error::LoadWithPersistError;
+use crate::error::MiniscriptError;
 use crate::error::PersistenceError;
 use crate::error::PsbtError;
 use crate::error::PsbtParseError;