rust: don't use wally_hash160

Since the inclusion of the miniscript feature and rust-miniscript dep,
we depend on rust-bitcoin and rust-hashes, so we can make use of it
instead of wrapping C code. This even saves ~40 bytes of binary space.

Author: benma

src/rust/bitbox02-rust/src/bip32.rs

@@ -18,6 +18,8 @@ use alloc::vec::Vec;
 
 pub use pb::btc_pub_request::XPubType;
 
+use bitcoin::hashes::Hash;
+
 #[derive(Clone)]
 pub struct Xpub {
     xpub: pb::XPub,
@@ -114,7 +116,9 @@ impl Xpub {
 
     /// Return the hash160 of the secp256k1 public key.
     pub fn pubkey_hash160(&self) -> Vec<u8> {
-        bitbox02::hash160(self.public_key()).to_vec()
+        bitcoin::hashes::hash160::Hash::hash(self.public_key())
+            .to_byte_array()
+            .to_vec()
     }
 
     /// Return the 65 byte secp256k1 compressed pubkey:

src/rust/bitbox02-rust/src/hww/api/bitcoin/common.rs

@@ -29,6 +29,8 @@ use super::{multisig, params::Params, script};
 
 use sha2::{Digest, Sha256};
 
+use bitcoin::hashes::Hash;
+
 const HASH160_LEN: usize = 20;
 const SHA256_LEN: usize = 32;
 
@@ -92,7 +94,9 @@ impl Payload {
                     Payload::from_simple(xpub_cache, params, SimpleType::P2wpkh, keypath)?;
                 let pkscript_p2wpkh = payload_p2wpkh.pk_script(params)?;
                 Ok(Payload {
-                    data: bitbox02::hash160(&pkscript_p2wpkh).to_vec(),
+                    data: bitcoin::hashes::hash160::Hash::hash(&pkscript_p2wpkh)
+                        .to_byte_array()
+                        .to_vec(),
                     output_type: BtcOutputType::P2sh,
                 })
             }
@@ -140,7 +144,9 @@ impl Payload {
             pb::btc_script_config::multisig::ScriptType::P2wshP2sh => {
                 let pkscript_p2wsh = payload_p2wsh.pk_script(params)?;
                 Ok(Payload {
-                    data: bitbox02::hash160(&pkscript_p2wsh).to_vec(),
+                    data: bitcoin::hashes::hash160::Hash::hash(&pkscript_p2wsh)
+                        .to_byte_array()
+                        .to_vec(),
                     output_type: BtcOutputType::P2sh,
                 })
             }

src/rust/bitbox02-sys/build.rs

@@ -139,7 +139,6 @@ const ALLOWLIST_FNS: &[&str] = &[
     "util_format_datetime",
     "wally_free_string",
     "wally_get_secp_context",
-    "wally_hash160",
     "wally_sha512",
 ];
 

src/rust/bitbox02/src/lib.rs

@@ -217,19 +217,6 @@ pub fn reboot() -> ! {
     loop {}
 }
 
-pub fn hash160(data: &[u8]) -> [u8; 20] {
-    let mut out = [0u8; 20];
-    unsafe {
-        bitbox02_sys::wally_hash160(
-            data.as_ptr(),
-            data.len() as _,
-            out.as_mut_ptr(),
-            out.len() as _,
-        );
-    }
-    out
-}
-
 #[cfg(feature = "testing")]
 pub fn reboot() -> ! {
     panic!("reboot called")