diff options
| author | Heiko Stuebner | 2020-07-07 22:57:26 +0200 |
|---|---|---|
| committer | Tom Rini | 2020-07-08 17:21:46 -0400 |
| commit | 49d0ea3746cae267b4f3c60c0e2e73dcac3d3213 (patch) | |
| tree | 25566beb1ca5919d3ef4bd04e73e9bacb677ac0e /lib | |
| parent | 8434b4373058018ee5b79f06f2cafd6b7c0c15e1 (diff) | |
lib: rsa: fix allocated size for rr and rrtmp in rsa_gen_key_prop()
When calculating rrtmp/rr rsa_gen_key_prop() tries to make
(((rlen + 31) >> 5) + 1) steps in the rr uint32_t array and
(((rlen + 7) >> 3) + 1) / 4 steps in uint32_t rrtmp[]
with rlen being num_bits * 2
On a 4096bit key this comes down to to 257 uint32_t elements
in rr and 256 elements in rrtmp but with the current allocation
rr and rrtmp only have 129 uint32_t elements.
On 2048bit keys this works by chance as the defined max_rsa_size=4096
allocates a suitable number of elements, but with an actual 4096bit key
this results in other memory parts getting overwritten.
So as suggested by Heinrich Schuchardt just use the actual bit-size
of the key as base for the size calculation, in turn making the code
compatible to any future keysizes.
Suggested-by: Heinrich Schuchardt <xypron.debian@gmx.de>
Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
rrtmp needs 2 + (((*prop)->num_bits * 2) >> 5) array elements.
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/rsa/rsa-keyprop.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/lib/rsa/rsa-keyprop.c b/lib/rsa/rsa-keyprop.c index 4b54db44c43..cc0d2f90669 100644 --- a/lib/rsa/rsa-keyprop.c +++ b/lib/rsa/rsa-keyprop.c @@ -654,14 +654,10 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop) { struct rsa_key rsa_key; uint32_t *n = NULL, *rr = NULL, *rrtmp = NULL; - const int max_rsa_size = 4096; int rlen, i, ret; *prop = calloc(sizeof(**prop), 1); - n = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); - rr = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); - rrtmp = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5)); - if (!(*prop) || !n || !rr || !rrtmp) { + if (!(*prop)) { ret = -ENOMEM; goto err; } @@ -682,6 +678,14 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop) } memcpy((void *)(*prop)->modulus, &rsa_key.n[i], rsa_key.n_sz - i); + n = calloc(sizeof(uint32_t), 1 + ((*prop)->num_bits >> 5)); + rr = calloc(sizeof(uint32_t), 1 + (((*prop)->num_bits * 2) >> 5)); + rrtmp = calloc(sizeof(uint32_t), 2 + (((*prop)->num_bits * 2) >> 5)); + if (!n || !rr || !rrtmp) { + ret = -ENOMEM; + goto err; + } + /* exponent */ (*prop)->public_exponent = calloc(1, sizeof(uint64_t)); if (!(*prop)->public_exponent) { |