Upgrade to secp256k1 0.21

Release 0.21 includes a module restructure which we can now make use of.
This simplifies some imports.

Cargo.toml

@@ -30,7 +30,7 @@ use-serde = ["serde", "secp256k1/serde"]
 use-rand = ["rand", "secp256k1/rand"]
 
 [dependencies]
-secp256k1 = "0.20.0"
+secp256k1 = "0.21.0"
 secp256k1-zkp-sys = { version = "0.5.0", default-features = false, path = "./secp256k1-zkp-sys" }
 rand = { version = "0.6", default-features = false, optional = true }
 serde = { version = "1.0", default-features = false, optional = true }

src/lib.rs

@@ -43,8 +43,6 @@ pub use secp256k1_zkp_sys as ffi;
 
 extern crate secp256k1;
 
-#[cfg(feature = "bitcoin_hashes")]
-pub use secp256k1::bitcoin_hashes as hashes;
 #[cfg(any(test, feature = "std"))]
 extern crate core;
 #[cfg(any(test, feature = "rand"))]
@@ -65,8 +63,6 @@ use core::{fmt, str};
 
 pub use secp256k1::*;
 
-pub use key::{PublicKey, SecretKey};
-
 #[cfg(feature = "serde")]
 mod serde_util;
 mod zkp;

src/zkp/ecdsa_adaptor.rs

@@ -13,10 +13,12 @@ use ffi::{self, CPtr, ECDSA_ADAPTOR_SIGNATURE_LENGTH};
 use rand::thread_rng;
 #[cfg(any(test, feature = "rand"))]
 use rand::{CryptoRng, Rng};
-use {constants, PublicKey, Secp256k1, SecretKey};
+use secp256k1::ecdsa::Signature;
+use secp256k1::{PublicKey, SecretKey};
+use Verification;
+use {constants, Secp256k1};
 use {from_hex, Error};
 use {Message, Signing};
-use {Signature, Verification};
 
 /// Represents an adaptor signature and dleq proof.
 #[derive(Debug, PartialEq, Clone, Copy, Eq)]
@@ -309,7 +311,7 @@ mod tests {
             .decrypt(&adaptor_secret)
             .expect("to be able to decrypt using the correct secret");
         SECP256K1
-            .verify(&msg, &sig, &pubkey)
+            .verify_ecdsa(&msg, &sig, &pubkey)
             .expect("signature to be valid");
         let recovered = adaptor_sig
             .recover(&SECP256K1, &sig, &adaptor)

src/zkp/rangeproof.rs

@@ -1,12 +1,13 @@
 use ffi::RANGEPROOF_MAX_LENGTH;
 use from_hex;
+use secp256k1::SecretKey;
 use std::ops::Range;
 use std::str;
 use Error;
 use Generator;
 use PedersenCommitment;
 use Verification;
-use {ffi, Secp256k1, SecretKey, Signing, Tweak};
+use {ffi, Secp256k1, Signing, Tweak};
 
 /// Represents a range proof.
 ///
@@ -203,7 +204,7 @@ impl RangeProof {
 #[cfg(feature = "bitcoin_hashes")]
 impl ::core::fmt::Display for RangeProof {
     fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
-        use bitcoin_hashes::hex::format_hex;
+        use hashes::hex::format_hex;
 
         format_hex(self.serialize().as_slice(), f)
     }

src/zkp/surjection_proof.rs

@@ -183,7 +183,7 @@ impl SurjectionProof {
 #[cfg(feature = "bitcoin_hashes")]
 impl ::core::fmt::Display for SurjectionProof {
     fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
-        use bitcoin_hashes::hex::format_hex;
+        use hashes::hex::format_hex;
 
         format_hex(self.serialize().as_slice(), f)
     }

src/zkp/whitelist.rs

@@ -10,7 +10,8 @@ use core::ptr;
 use ffi::CPtr;
 #[cfg(feature = "std")]
 use from_hex;
-use {ffi, secp256k1, Error, PublicKey, Secp256k1, SecretKey, Signing, Verification};
+use secp256k1::{PublicKey, SecretKey};
+use {ffi, secp256k1, Error, Secp256k1, Signing, Verification};
 
 /// A whitelist ring signature.
 #[derive(Clone, PartialEq, Eq, Hash)]