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@xxxxxxxxxxxxxxxxxxxxx> your e-mail address looks incorrect [...] -- Best regards, Kamil Konieczny Samsung R&D Institute Poland
