[PATCH v5 5/8] lib: rsa: free local arrays after use in rsa_gen_key_prop()

Heiko Stuebner
2020-05-22T14:19:34Z

n, rr and rrtmp are used for internal calculations, but in the end
the results are copied into separately allocated elements of the
actual key_prop, so the n, rr and rrtmp elements are not used anymore
when returning from the function and should of course be freed.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
---
changes in v4:
- new patch

lib/rsa/rsa-keyprop.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/lib/rsa/rsa-keyprop.c b/lib/rsa/rsa-keyprop.c
index e28fbb7472..ac33b35ff9 100644
--- a/lib/rsa/rsa-keyprop.c
+++ b/lib/rsa/rsa-keyprop.c
@@ -655,7 +655,7 @@ 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;
+ int rlen, i, ret = 0;

*prop = calloc(sizeof(**prop), 1);
n = calloc(sizeof(uint32_t), 1 + (max_rsa_size >> 5));
@@ -663,12 +663,12 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop)
rrtmp = calloc(sizeof(uint32_t), 1 + ((max_rsa_size * 2) >> 5));
if (!(*prop) || !n || !rr || !rrtmp) {
ret = -ENOMEM;
- goto err;
+ goto out;
}

ret = rsa_parse_pub_key(&rsa_key, key, keylen);
if (ret)
- goto err;
+ goto out;

/* modulus */
/* removing leading 0's */
@@ -678,7 +678,7 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop)
(*prop)->modulus = malloc(rsa_key.n_sz - i);
if (!(*prop)->modulus) {
ret = -ENOMEM;
- goto err;
+ goto out;
}
memcpy((void *)(*prop)->modulus, &rsa_key.n[i], rsa_key.n_sz - i);

@@ -686,7 +686,7 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop)
(*prop)->public_exponent = calloc(1, sizeof(uint64_t));
if (!(*prop)->public_exponent) {
ret = -ENOMEM;
- goto err;
+ goto out;
}
memcpy((void *)(*prop)->public_exponent + sizeof(uint64_t)
- rsa_key.e_sz,
@@ -710,16 +710,15 @@ int rsa_gen_key_prop(const void *key, uint32_t keylen, struct key_prop **prop)
(*prop)->rr = malloc(rlen);
if (!(*prop)->rr) {
ret = -ENOMEM;
- goto err;
+ goto out;
}
br_i32_encode((void *)(*prop)->rr, rlen, rr);

- return 0;
-
-err:
+out:
free(n);
free(rr);
free(rrtmp);
- rsa_free_key_prop(*prop);
+ if (ret < 0)
+ rsa_free_key_prop(*prop);
return ret;
}
--
2.25.1