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| author | Heiko Stuebner <heiko.stuebner@theobroma-systems.com> | 2020-05-03 13:26:34 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2020-05-07 09:01:42 -0400 |
| commit | fdf0819afb5b7a8757ba1b4fdfe14f3767ab7e87 (patch) | |
| tree | 42641387fa77a883ffe4d51227f6b5fad39dc399 /lib/rsa | |
| parent | c2a2123e33371b2dc3406789764996d4fa73aac3 (diff) | |
| download | u-boot-fdf0819afb5b7a8757ba1b4fdfe14f3767ab7e87.tar.gz u-boot-fdf0819afb5b7a8757ba1b4fdfe14f3767ab7e87.tar.bz2 u-boot-fdf0819afb5b7a8757ba1b4fdfe14f3767ab7e87.zip | |
rsa: fix alignment issue when getting public exponent
To fill the exponent field of the rsa_public_key struct, rsa_mod_exp_sw
did a cast to uint64_t of the key_prop->public_exponent field.
But that alignment is not guaranteed in all cases.
This came to light when in my spl-fit-signature the key-name exceeded
a certain length and with it the verification then started failing.
(naming it "integrity" worked fine, "integrity-uboot" failed)
key_prop.public_exponent itself is actually a void-pointer, fdt_getprop()
also just returns such a void-pointer and inside the devicetree the 64bit
exponent is represented as 2 32bit numbers, so assuming a 64bit alignment
can lead to false reads.
So just use the already existing rsa_convert_big_endian() to do the actual
conversion from the dt's big-endian to the needed uint64 value.
Fixes: fc2f4246b4b3 ("rsa: Split the rsa-verify to separate the modular exponentiation")
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'lib/rsa')
| -rw-r--r-- | lib/rsa/rsa-mod-exp.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/rsa/rsa-mod-exp.c b/lib/rsa/rsa-mod-exp.c index 420ab2eba0..62b2557cc2 100644 --- a/lib/rsa/rsa-mod-exp.c +++ b/lib/rsa/rsa-mod-exp.c @@ -262,8 +262,8 @@ int rsa_mod_exp_sw(const uint8_t *sig, uint32_t sig_len, if (!prop->public_exponent) key.exponent = RSA_DEFAULT_PUBEXP; else - key.exponent = - fdt64_to_cpu(*((uint64_t *)(prop->public_exponent))); + rsa_convert_big_endian((uint32_t *)&key.exponent, + prop->public_exponent, 2); if (!key.len || !prop->modulus || !prop->rr) { debug("%s: Missing RSA key info", __func__); |