RSA signature verification fails with mbedtls and openssl against signature generated from libtomcrypt

[dam...@chirp.io]

Hi,

I already created an issue on StackOverflow (https://stackoverflow.com/questions/55613950/rsa-signature-verification-failing-with-libtomcrypt) but haven't had any answer yet so I will make it short on here :)

My issue is that a signature generated with libtomcrypt fails to be verified by either mbedtls or openssl. I would like to know if it's a bug with my code or a bug from libtomcrypt, which would really surprise me.

Thank you !
Damien

[Steffen Jaeckel]

I took the liberty to reply on SO.

For all of you who don't want to go there... Damien forgot to hash the
input before calling `rsa_sign_hash()`

It's true that this point isn't explicitly stated in the documentation
that "you probably have to hash the data before passing it in", so this
could be improved.


Cheers,
Steffen

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[dam...@chirp.io]

Hi Steffen,

I validated your answer on SO as it fixed the issue. I repeat myself but my bad, I misread the documentation.

Thanks for your quick support !

Damien

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