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digest: type name readability regression #1069
Description
Activity
could be fixed by using newtypes around the generic core, rather than just type aliases.
It will involve a quite significant amount of boilerplate in every hash crate.
I think with some experimentation we can find a solution which allows newtypes for each hash type while minimizing per-crate boilerplate.
Alternatively perhaps we could find more meaningful names for the generic types which make the generic types more readable.
Or a combination thereof.
In RustCrypto/RSA#179 we ran into a somewhat related issue:
It would be nice to be able to use the
const_oid::AssociatedOidtrait to associate an OID with types likeSha224/Sha256/Sha384/Sha512.Unfortunately this isn't possible because these types are actually
CoreWrapper<CtVariableCoreWrapper<...>as defined by thedigestcrate.Something I think is worth noting is the orphan rules would probably permit such an impl if the inner generic type were defined in the current crate (leveraging the same exemption
Fromuses), but that doesn't work with multiple layers of generics like this.I think
digestcan implementAssociatedOidfor the wrappers if a wrapped type implements it. In other words, we would implementAssociatedOidfor core types anddigestwill handle "bubbling" it to the types used by users.Potentially relevant issue: rust-lang/rust#66751
Reacted by Tony ArcieriRe: newtypes, using macros for delegation is one option as mentioned here: #1098 (comment)
FWIW I don't think it's a terrible option. Macros are best used as stopgaps for missing language features, and I think the lack of first-class delegation support (especially in a composition-over-inheritance language) is a reasonable use case for macros. I also think lack of first-class delegation is somewhat widely recognized as a deficiency in Rust which should eventually get addressed somehow. See rust-lang/rfcs#2393
We use them for solving a similar problem related to
AssociatedOidhere: https://docs.rs/x509-cert/latest/x509_cert/macro.impl_newtype.htmlAlternatively
Derefcould be used, potentially in combination with macros.Along these same lines, the error messages for when a digest type fails to impl the #1098 approach to
AssociatedOidmakes for a fairly inscrutable error message:error[E0599]: the function or associated item `new_with_prefix` exists for struct `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>`, but its trait bounds were not satisfied --> ssh-key/src/signature.rs:403:52 | 403 | let data = pkcs1v15::SigningKey::<Sha512>::new_with_prefix(self) | ^^^^^^^^^^^^^^^ function or associated item cannot be called on `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>` due to unsatisfied trait bounds | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/rsa-0.7.0-rc.0/src/pkcs1v15.rs:306:1 | 306 | pub struct SigningKey<D> | ------------------------ | | | doesn't satisfy `_: Default` | doesn't satisfy `_: FixedOutput` | doesn't satisfy `_: HashMarker` | doesn't satisfy `_: Update` | doesn't satisfy `_: sha2::Digest` | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/digest-0.10.5/src/core_api/wrapper.rs:24:1 | 24 | pub struct CoreWrapper<T> | ------------------------- doesn't satisfy `_: AssociatedOid` | = note: the following trait bounds were not satisfied: `CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>: AssociatedOid`...and for me this error continues (possibly unrelated):
`rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `&rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `&mut rsa::pkcs1v15::SigningKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` error[E0599]: the function or associated item `new_with_prefix` exists for struct `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>`, but its trait bounds were not satisfied --> ssh-key/src/signature.rs:427:51 | 427 | pkcs1v15::VerifyingKey::<Sha256>::new_with_prefix(self) | ^^^^^^^^^^^^^^^ function or associated item cannot be called on `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>` due to unsatisfied trait bounds | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/rsa-0.7.0-rc.0/src/pkcs1v15.rs:406:1 | 406 | pub struct VerifyingKey<D> | -------------------------- | | | doesn't satisfy `_: Default` | doesn't satisfy `_: FixedOutput` | doesn't satisfy `_: HashMarker` | doesn't satisfy `_: Update` | doesn't satisfy `_: sha2::Digest` | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/digest-0.10.5/src/core_api/wrapper.rs:24:1 | 24 | pub struct CoreWrapper<T> | ------------------------- doesn't satisfy `_: AssociatedOid` | = note: the following trait bounds were not satisfied: `CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>: AssociatedOid` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: FixedOutput` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Default` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Update` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: HashMarker` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: FixedOutput` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Default` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Update` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: HashMarker` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: FixedOutput` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Default` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: Update` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: HashMarker` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, OidSha256>>>: sha2::Digest` error[E0599]: the function or associated item `new_with_prefix` exists for struct `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>`, but its trait bounds were not satisfied --> ssh-key/src/signature.rs:435:51 | 435 | pkcs1v15::VerifyingKey::<Sha512>::new_with_prefix(self) | ^^^^^^^^^^^^^^^ function or associated item cannot be called on `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>` due to unsatisfied trait bounds | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/rsa-0.7.0-rc.0/src/pkcs1v15.rs:406:1 | 406 | pub struct VerifyingKey<D> | -------------------------- | | | doesn't satisfy `_: Default` | doesn't satisfy `_: FixedOutput` | doesn't satisfy `_: HashMarker` | doesn't satisfy `_: Update` | doesn't satisfy `_: sha2::Digest` | ::: /Users/bascule/.cargo/registry/src/github.com-1ecc6299db9ec823/digest-0.10.5/src/core_api/wrapper.rs:24:1 | 24 | pub struct CoreWrapper<T> | ------------------------- doesn't satisfy `_: AssociatedOid` | = note: the following trait bounds were not satisfied: `CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>: AssociatedOid` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `&rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: FixedOutput` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Default` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: Update` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest` `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: HashMarker` which is required by `&mut rsa::pkcs1v15::VerifyingKey<CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>, OidSha512>>>: sha2::Digest`A note re: above: it becomes very very hard to tell what's happening when dealing with errors like above but trying to figure out e.g.
Sha256vsSha512, as these are:SHA-256
CoreWrapper<CtVariableCoreWrapper<Sha256VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>>>
SHA-512
CoreWrapper<CtVariableCoreWrapper<Sha512VarCore, signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<signature::digest::typenum::UInt<UTerm, B1>, B0>, B0>, B0>, B0>, B0>, B0>>>>
There is just so much syntactic noise the actual important parts become very difficult to find/compare.
The solution to all of the above was to enable the
oidfeature ofsha2, however arriving at that was incredibly counterintuitive given the error messages, and that's coming from the perspective of a developer of these crates.For now we're going to need to make all of this very clear in the documentation, with examples of the error messages and suggested resolutions.
Most of the noise comes from
typenum, with const generics we would get something likeCoreWrapper<CtVariableCoreWrapper<Sha512VarCore, 64>>>, which is not ideal, but still much better. I wonder if something like this could help eventually.Regardless of the horrible error messages, maybe we should make the
oidfeature enabled by default or even make it non-gated in the next breaking releases?Reacted by Tony Arcieri
Digest now makes use of several vaguely-named generic wrapper structs and type aliases to give them human-readable names.
This makes both the type names emitted by rustc and the resulting rustdoc harder to read, as they render the canonical type name rather than the type alias.
For example, what used to render in rustdoc as:
now renders as:
e.g. https://docs.rs/k256/0.11.3/k256/schnorr/struct.Signature.html#impl-PrehashSignature
I think this usability issue and various others (e.g. confusing error messages relating to blanket impls of sealed traits) could be fixed by using newtypes around the generic core, rather than just type aliases.