Add SHA-512/224 and SHA-512/256 hash functions #55
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Ok. It isn’t as easy as I thought. Found test with longer messages, and for them it does not work (only for one block messages). I believe I’ll need to make proxy structs with 512 bits output for both hash functions and copying first bytes of result. |
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I think that we should find way to achieve writing |
Use `copy_nonoverlapping` instead loops This resolves issue with strange SHA-512/224 additional struct in #55.
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Could you fix the PR to not use |
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Will do that soon. User cannot truncate output by himself from SHA-512 because the initial values are different. SHA-512/224 and SHA-512/256 are practically identical to SHA-384 in terms of relation to SHA-512. SHA-384 is not called SHA-512/384 probably only because there is no 384 hash function using 32 bit words. |
hauleth
changed the title
…a512_224 and Sha512_256 to Sha512224 and Sha512256
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@homu r+ |
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📌 Commit 8be3dfc has been approved by |
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⚡ Test exempted - status |
Add SHA-512/224 and SHA-512/256 hash functions SHA2-512/224 and SHA-512/256 implemented, using existing macros for sha2 functions. However, SHA2-512/224 has 224 bits, and that is not a multiple of 64. Thus, `write_u64()` used for writing state to resulting `out` slice cannot be used directly (as it would copy 4 bytes to few to out, or 4 to many). Because of that a *proxy* struct `_Sha512_224` which outputs 256 bits is created, and its methods are simply called by proper `Sha512_224` struct. In the `result()` method a new vec, `res` is created, result is written to it, and then 28 first bytes are copied to `out` using a simple for loop. SHA2-512/256 is implemented with just `impl_sha!(high Sha512_256, SHA512_256_INIT, 256)`. It closes #47.
SHA2-512/224 and SHA-512/256 implemented, using existing macros for sha2 functions. However, SHA2-512/224 has 224 bits, and that is not a multiple of 64. Thus,
write_u64()used for writing state to resultingoutslice cannot be used directly (as it would copy 4 bytes to few to out, or 4 to many).Because of that a proxy struct
_Sha512_224which outputs 256 bits is created, and its methods are simply called by properSha512_224struct. In theresult()method a new vec,resis created, result is written to it, and then 28 first bytes are copied tooutusing a simple for loop.SHA2-512/256 is implemented with just
impl_sha!(high Sha512_256, SHA512_256_INIT, 256).It closes #47.