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author | Maciej S. Szmigiero <mail@maciej.szmigiero.name> | 2018-05-19 14:23:54 +0200 |
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committer | James Morris <james.morris@microsoft.com> | 2018-06-25 12:17:08 -0700 |
commit | 8d03c9c3ae3088eb938ba26fbe9374353e5f97e9 (patch) | |
tree | 8d3a2ee60a0083af58339ffc385e3a48db5fe4f2 /crypto/lrw.c | |
parent | 74166d72810cbba7a17154caee1a182e361247b1 (diff) | |
download | linux-crypto-8d03c9c3ae3088eb938ba26fbe9374353e5f97e9.tar.gz linux-crypto-8d03c9c3ae3088eb938ba26fbe9374353e5f97e9.zip |
X.509: unpack RSA signatureValue field from BIT STRING
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>
Fixes: de26a46f6c58 ("X.509: Add a crypto key parser for binary (DER) X.509 certificates")
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.morris@microsoft.com>
Diffstat (limited to 'crypto/lrw.c')
0 files changed, 0 insertions, 0 deletions