Messages in this thread | | | Subject | Re: [PATCH v2] X.509: unpack RSA signatureValue field from BIT STRING | From | "Maciej S. Szmigiero" <> | Date | Tue, 17 Apr 2018 17:11:54 +0200 |
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On 17.04.2018 17:07, Kamil Konieczny wrote: > > > On 17.04.2018 15:39, Maciej S. Szmigiero wrote: >> The signatureValue field of a X.509 certificate is encoded as a BIT STRING. >> For RSA signatures this BIT STRING is of so-called primitive subtype, which >> contains a u8 prefix indicating a count of unused bits in the encoding. >> >> We have to strip this prefix from signature data, just as we already do for >> key data in x509_extract_key_data() function. >> >> This wasn't noticed earlier because this prefix byte is zero for RSA key >> sizes divisible by 8. Since BIT STRING is a big-endian encoding adding zero >> prefixes has no bearing on its value. >> >> The signature length, however was incorrect, which is a problem for RSA >> implementations that need it to be exactly correct (like AMD CCP). >> >> Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> > > your e-mail address looks incorrect > > [...] >
What's wrong with it?
Maciej
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