Messages in this thread | | | Subject | Re: [PATCH v2][RESEND] X.509: unpack RSA signatureValue field from BIT STRING | From | "Maciej S. Szmigiero" <> | Date | Wed, 20 Jun 2018 14:24:54 +0200 |
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On 02.06.2018 21:12, Maciej S. Szmigiero wrote: > On 19.05.2018 14:23, 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). > > Any progress here? > This simple patch has already been submitted 3 times in last 3+ months... >
A friendly ping here.
@AMD people: Without this patch, in-kernel X.509 certificate verification is broken on AMD CCP RSA implementation.
For example, loading wireless regulatory database gives the following errors: > [ 21.310361] cfg80211: Problem loading in-kernel X.509 certificate (-22) > [ 21.351717] cfg80211: loaded regulatory.db is malformed or signature is missing/invalid
Kernel modules signature verification probably has similar problem, too.
That's why it would be nice if you could ack this patch, please.
Maciej
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