feat: provide hex serialization utilities

A couple of functions are added to serialize and deserialize a `Dbc` to and from a hex encoded
string.

At the moment `sn_cli` needs to perform these conversions, but we decided it would be useful to have
them on the `Dbc` type.

There is also a little change here to switch off verbose output for Cargo on the PR workflow. There
really isn't a lot of useful information from the build process and it clutters the logs.

.github/workflows/pr.yml

@@ -8,8 +8,6 @@ name: PR
 on: pull_request
 
 env:
-  # Run all cargo commands with --verbose.
-  CARGO_TERM_VERBOSE: true
   RUST_BACKTRACE: 1
   # Deny all compiler warnings.
   RUSTFLAGS: "-D warnings"

Cargo.toml

@@ -15,6 +15,7 @@ ringct-serde = [ "bls_ringct/serde" ]
 mock = [ ]
 
 [dependencies]
+bincode = "1.3.3"
 blsttc = "5.2.0"
 bls_ringct = "0.2.0"
 hex = "0.4.3"
@@ -31,7 +32,6 @@ thiserror = "1.0.24"
 
 [dev-dependencies]
 anyhow = "1.0.40"
-bincode = "1.3.3"
 criterion = "0.3.5"
 quickcheck_macros = "1"
 quickcheck = "1.0.3"

src/dbc.rs

@@ -216,6 +216,26 @@ impl Dbc {
         self.verify(&self.owner_base().secret_key()?, verifier)
     }
 
+    /// Deserializes a `Dbc` represented as a hex string to a `Dbc`.
+    #[cfg(feature = "serde")]
+    pub fn from_hex(hex: &str) -> Result<Self, Error> {
+        let mut bytes =
+            hex::decode(hex).map_err(|e| Error::HexDeserializationFailed(e.to_string()))?;
+        bytes.reverse();
+        let dbc: Dbc = bincode::deserialize(&bytes)
+            .map_err(|e| Error::HexDeserializationFailed(e.to_string()))?;
+        Ok(dbc)
+    }
+
+    /// Serialize this `Dbc` instance to a hex string.
+    #[cfg(feature = "serde")]
+    pub fn to_hex(&self) -> Result<String, Error> {
+        let mut serialized =
+            bincode::serialize(&self).map_err(|e| Error::HexSerializationFailed(e.to_string()))?;
+        serialized.reverse();
+        Ok(hex::encode(serialized))
+    }
+
     /// Checks if the provided AmountSecrets matches the amount commitment.
     /// note that both the amount and blinding_factor must be correct.
     ///
@@ -279,6 +299,8 @@ pub(crate) mod tests {
         })
     }
 
+    const DBC_WITH_1_530_000_000: &str = "2fce3f70d7ad38d48d81f3f67c11ea10388a95efff66ce444f3274fb261c119a839e3de7a4c97b3b2b12fde3af09990ed20f48b3a23d79ca9b39cf0b6f492b142c03d3c0ee34d087fa3b9989cab7f7fb4e2328587330ce226277b8062881b3a231b11365712ad3a82ece13af3699fb171f16001af12522a92d1cf6d788a919bf7aa7bc1cd70f0eac4f96967bdd9cb38338aab683457882ebc8dc80cd829f9e292837a00789952636524a544ae1fada10439ed9478b6d0127c5fd13ed74e9e1870000000000000001c428455eb4b5485f9465049a3a1b519a89b50ec3bef0c4ebbf45b7198cc348321ca2ae5ab0ed3dc52cc9cd341c4a482e9d9f5f2d81d981a11032821603b863baa19a900087052a2f799092f29d7e2c8b00000000000000016caf52b6919fa145146588809f6c0d2a0b70053c9501a52730bbfba00de94dfe72f14801d29d5b2d93c8b626d443498d34bf24d89d5012a6067ccb301919272553dcdf50cbf95240e47a3c7e967ba98e70b2a97e866c810a0ba806bb96a1b8308eb9b22b29b44ea5d33ae9e9c057261b09e21456123981952224dbf9cadfd50cfb02e0dc57ce55156f844c3a2c704a5be432d2444765dd15beb7fca57a20508f73df1043f8e2e5d8a56a2fb17fe475f2cca88c8d23eae27f3d172e3d6fad45c1b3232dc10ee46a7016df417935865a99b3761bffdefea6373584f50258ab9d60cddfc80ed76c9454bcaa8083f58e6c53d3095e06b02638eccd668031cf232b87ea9474b4166849a34ffbc805310520c8b19bafa7424df714becb9ce02d6d705b51b168a0b806798da550a0807fc1a8a9122908dbbd7e4838e65a9c9bdbc1fbf3e11a79187444274a828618e4debbcc3cee1ea0d1a157f21b8624bccc8eb58c91a60d84deb16ac42241ace0f3174c3abbca0d3331990e7c6db07ff24c8537060ea76348f96af31927c49c84a4e2c4cb8cdd95f86c0fcc18cb1d6c2a519ced3ad2e9903061dd3f3c8e02fafd969f53f52274faddb0b4f5aef19dc0e62277cbcda3e3ac39cfa4b709efbbdab65440a42e628fff051c83acd583a5e3bbfb2eb4807c5aa2303c7b52f1d539899572b674bd8fb4a529354e8087067a4e374e92b855a7ec523295867f310f7cea5d48bb0295a1c3ea47b6c4229f000d0c83ae22eb449656c25083a5fc99f99a23cf25fc2020941ffb392b3c8788c25b687b21610d35e3a5f12974b20778144d6930772381a694be5605f21142ca2121a7358e377fd20d50ff00ae3550aa2622ac8d8a642c41aec117b74c22732b297dbb4e4637595bb5b7d5a69414c7822e55efb9c40ddbc2a293532ee49c705e9bb2f3fff3f2dcce8c72b90c486b3a750ee594fd2b04c2dd9553e02a226001956bed24790349d243ca5d51167c4a348d19e42bf2cabc72c0510b8217e0ce5997b763fd11a881c8757f565e3ca3766fc5c3e011ad40d634666859a3a5fdbab6fb627c5abd1d80894424c5a1b0de74cfdf5eb17b9c8bb873f4515adc3e9d62d76f4f5bbb0ef453e369ad5ffa853ab6661f2bf242d91d098f5c59ceb4c1151b47f4cd5ee9dc98daca45898168f4ff69fb230d01d7660d0718cc1b6facbb7f8e9a73cb6a8b93aba7dddc450628588fbb916641abaab4a228bc2584950e34f86a8154b4f5773d07a4ad70b9c2fdff3d16933011664e8de0298c61cd2da7511b8a0cd63acf47156bd7f667929fce5b7257582f336683abf609ad7a4b9dca4395849d81da230d13822d01224d49f4d249d9881d2e876335824514448300000000000003a00af4916a22e0177947732d2d58db7e0325d004f1de5718b3275ae009845fa53ce6948ddd9623e445c8433d30c162c9a22b05a80d417ac2efc2bf684e091bc26a81bda1ec9253ed4657c2440710623741007bdb90e9d94121babea7484d25a49432e71b55250be2a5c8ac7716ec2c61218cca98458ae648e11d31c185d20e1eb21300e7b360f1553a128ff97d54c1510a26178421859bef1dae17e4cf496acc39b20059e48b5c94c7ab244dbfc368d12868af7cac467d8c18e8cb5b60c22b7e9151e013dd28b813254e65a73c24c0efae47b29cdc3a34286dabb6fd09d9ad8b121655394d272934013773667eae726cdbab0b42cfc2c0bd988ecacafead6f179046fa3a4f5fb8ca7a790e5685f262c0e770c20a700fdab00aeac3a8634d84102f750996b5323356ad1b3199702c2d23a64279726f35e0eb630f91794dda905093995d6b457782792564be257a191f2bdeedd01e76051f7aa740735b8c408c618b3b6edac93f7504d441855d89adb6e13ed2a60c81ac0a0b445a2d1447bc30f0f30376ab55995ad0b639c1dfddb3e29e8f8ddccb59e55d863117ca6bc1c8dbf42983ea889cd03b19ab7c76addddb6dbdd53856b92df8cc929f3d37eb27ba6ab68194fc55f9ca2943acd265538751335cdbf527675494d176282e59a9c8deb95645b5b2b8660456434701b182e08915dbb6de5bfacc5480e867a9f08c8fe2d209eaa44175912ce5fb782425e264587d8ad13a70eb83d0ac0b02095a8f6d029d588b80b4f7a96c73720344247eae9613a9ff6ca368dbd823c225304725a36aee0c1822fe554733bc074c50ea296ff6b60c8711f7ef216e1ff1b532b398ba13e6da8ebd4546dcf296a4c1f7b27da5ec6e771d23afc139af51d5e9b5f2be9f32a7ab949e86cb5158c0f61b5a31f81e9c9ddc8412fcdf971a7cc296e742bcae1d444928152841a927dd7985bb7ef06c1fcfa9a1b908e6b0f52a38321f325f4bff3af4064ce8266c93821bb81f9a0404ffff81520ff370ba1b831cae5db58cb943e59dac65a9092db9fb12b00424c49dc0b92356a5b2801c40b43f8d5262278b44eb980e5857397b6ec9570dde9ca80b5ab041bf81872f3f999182589771a75c8ef0e3b8603888dade9b1d449adaac0f08c7cddbe85df0871722ded236de4b7e5f999ad3f2c8e01cab184eaec5f2fa35b22586e7838e4dde010a37ff24927c8a4845794ee699ab54b57ba50e038008af5ea0bbaf3f4e627fe03809f973980b81ced08a602b7458158ab7684376535265761dc039bb13d01ff90e732b8df17d783338db830193034d48dca8ed42b077293db0aa1da1b14c0c4c0e76c7859b832a226464e2cad01aa41bf8fd1686933b55fd961ab336cdb697e851bf3b6c1142019475e0b2925d6727e15de30cbf7b342daf509778d2af676c53a3e962ddff846c310d768e00000000000003a058998e2c08c59208820948b33b051910a3156d3beff7984798c030f971904a9085c61447ded4a76575b5fcc40b5acd93b1d0b17ba74231d94f3df0f666e751067fdc9364a3a5d07ce0881d44fabf4cf0f478a2ec3d14a668e3e5f249d57138890a5db2846b458f82e77256f2f4b3f1412b0434831aad2b96fed8c9ed2e520a5c54ddfb9f72ee0932eea6ab7a58b2f14c5ef062717e9d1da9c7f213dd11bed65bd7693398c732e08b6fe96095c68e4d7e2d3378c3632e736358e88db56bad7329bfd83bac50c0649fcf4f8baf1f95a3b16a004a02b8d0a469b687ee7f91743232a46ae0eb27d0f45d18dcbc04aeb9595995802a4ddf42f2712248d38d5b7656916211ecc6bbfb4c62b6f9d3393061ead919662e53f356bf2327536dccedd7eee28b06514de978fcc965a3d6d507aba3b3af78e3ac52e3141e9fc1b51302616138f2e14ba340d1baea0b2d3d65e21fc94545f17e956292b4cfa8eaecdfa46344a88eb15f9e230a384caefaced24f6553f5ba7c7e41f9c9bbec71a9a5d8a33b994b6d1ce62a1334351057838c2fbe0aa3a204c17fb11e1970f36a8ef3a16d634890a98dee795c197ad586a5c0cf5a23e72d5931481ddf33a342c5bcc320965b98b46bfc2c51a106ce2dedc8f7196b1af0f30825854d5a34d7fc398aea4548e13d0289fe76ec71f4d9531e56d44d39562ca349fd9b62321e28e7d1c1c406199b5dd4841e12d1c649e9e3dd7db84c8499f61621c188fcf56da4915001bc82a8b8aaafa7001486df8dc215d02261640dfce04c79ba5d66ea5daec4fe8a7f2e39527c8c5ca8d8e05fe00e9f909d49a852a9c2ab96f185aa63ccd5e542b0355d8ee66b252a5a57ab0b30c704ea8055eea246d5700c0aadf23520a445e70b331b24fb8f8c43739403cba21d87a6a63e05cddfcf6934230c4f9420b796b70df0eb70f0c1a94c09c70b7e1bb6e2494fe4ae028c358a9048404e31e6191749b83f8cc942fc796459ce1669ea7c268d3c55cb2be9e8ed54400cd831c974fe59d63b043963e98330c7179038c3be277bcb8d9713234a48a7f2e84bdc41c6f822e7292a02407c9966834fc014727d1aa86ca08f39d5fb53b745bb16d2eb11f23af7955b1a5507ff670dc39d8bd929a2ac8ad2e72ed27d36c386223672d434474f9149d39079bd72977f573bee8686584eddcb1467c24c16a38b0e6f6a9c727f7cca2b7a7a86589fa507438ee0bdaa383ddb95ac2d3abe8d07fe06dc4980bbf6423d7496d4283f85cfc9dc79091eb8695d583ebf31a6aad857a6510e3bf268b634ec62ee7112be92a89633f394792332d8e0f5fcff45353bf8e55db172dae5d60dacd372c1e47f9ce8d497f7a18438fe6a3930c240b29ab1d91176ebd5934d23230b629f46f294f9926d4f33c5ba2c1cee78df2b3bb2d43c67423751cfd78ec652596dec00a06db900000000000003a0d28d2cf0c4c23a0ae40ab3a4a29ed7eaa11a3957bf5ee7b8e61c4f3858982f5fe8f40bb19cf728f76121c2cd51ab9a970000000000000003e8c9885501863a2462cf63cd2d4109746aeda1643d286fd6fb13014bef689dc66b34b6e5a6f83e88aead415c06737aaee5eb3c7fda86f635b3345c72329088cbae5eb375e33f880727993c4c01b736f93fc1520f3fa1b41a8c8eb7002dd6a1a996535faeae2d5b27e4c0b37f2d8667128dbe048a2814ce4d24fc60f7a0dda7c87e1d3b30254c25aba701ff6eeb9ebe8800000000000000011ca2ae5ab0ed3dc52cc9cd341c4a482e9d9f5f2d81d981a11032821603b863baa19a900087052a2f799092f29d7e2c8b158a686df05f9cb8c9f01f6499b27d21c499d31ad7d8274c4dff49192e73c184018a600ba8fc0e3734dd643706ae2af8922fffa4574a630845a4a91f0ce23518000000000000000125cf08c3ee49b669e5cfb0ad13de8e19691287addf6b5228a78fc769ce76c74e0000000000000001975d70bd51172f6374af4a6caef9cf309579710d8de8544924a4b3e1dea66268cbb03d16b627871f3953107611f586177d5513c8577e1f1d6fe32db8e15652c342c3962968a07e584544049e05cfcc50692e5dc7dbb8eaf492c6b8191083f1a363b6ab807e54f04f4a7d0dd03097354d733baa72c8c74fd4705afdca689209f566a27c010f60cc64000000000000002886ec356465a6f1f026d858b4379d94d26c85b519261f1aec7ef751dbb7047e0a0d4c5c554d6c0859d3f81ffc8c67d5923165c636f32ee6cf3aee685d84a38cd411a0007ab583cc18985830be0c634b132890055ab792751ac4154645f5fc0a00697d0b202f3bc1ed194875eb59dcacc7482ce06feb934e8409ba391e56537c02b599c54b173e9ac920d9f14af16cfa9649bd35c0d4b1425f35f9c2f49f7c441b9c02bc2eb97e318b76aa4dabc55a76f40000000000000020c0f8550862860085c4f90ac96b053dfa355be3de55a341c24ea20c3ae0050e4649bbf5aa9b06c678717d7582308bd68aafdf11a379bc34056f56c762e11d1340239b777df26c543ff1e61fd0066e842400000000";
+
     fn prepare_even_split(
         dbc_owner: SecretKey,
         amount_secrets: AmountSecrets,
@@ -307,6 +329,47 @@ pub(crate) mod tests {
         Ok(dbc_builder)
     }
 
+    #[test]
+    fn from_hex_should_deserialize_a_hex_encoded_string_to_a_dbc() -> Result<(), Error> {
+        let dbc = Dbc::from_hex(DBC_WITH_1_530_000_000)?;
+        let amount = dbc.amount_secrets_bearer()?.amount();
+        assert_eq!(amount, 1_530_000_000);
+        Ok(())
+    }
+
+    #[test]
+    fn to_hex_should_serialize_a_dbc_to_a_hex_encoded_string() -> Result<(), Error> {
+        let mut rng = crate::rng::from_seed([0u8; 32]);
+        let amount = 100;
+        let owner_once =
+            OwnerOnce::from_owner_base(Owner::from_random_secret_key(&mut rng), &mut rng);
+        let ringct_material = RingCtMaterial {
+            inputs: vec![],
+            outputs: vec![Output::new(owner_once.as_owner().public_key(), amount)],
+        };
+        let (transaction, revealed_commitments) = ringct_material
+            .sign(&mut rng)
+            .expect("Failed to sign transaction");
+        let input_content = DbcContent::from((
+            owner_once.owner_base.clone(),
+            owner_once.derivation_index,
+            AmountSecrets::from(revealed_commitments[0]),
+        ));
+        let dbc = Dbc {
+            content: input_content,
+            transaction,
+            spent_proofs: Default::default(),
+        };
+
+        let hex = dbc.to_hex()?;
+
+        let dbc_from_hex = Dbc::from_hex(&hex)?;
+        let left = dbc.amount_secrets_bearer()?.amount();
+        let right = dbc_from_hex.amount_secrets_bearer()?.amount();
+        assert_eq!(left, right);
+        Ok(())
+    }
+
     #[test]
     fn test_dbc_without_inputs_fails_verification() -> Result<(), Error> {
         let mut rng = crate::rng::from_seed([0u8; 32]);

src/error.rs

@@ -72,6 +72,12 @@ pub enum Error {
     #[error("Secret key does not match public key")]
     SecretKeyDoesNotMatchPublicKey,
 
+    #[error("Could not deserialize specified hex string to a DBC: {0}")]
+    HexDeserializationFailed(String),
+
+    #[error("Could not serialize DBC to hex: {0}")]
+    HexSerializationFailed(String),
+
     #[error("Bls error: {0}")]
     Blsttc(#[from] blsttc::error::Error),