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authorDoug Hogan <[email protected]>2019-01-03 18:46:08 -0800
committerDoug Hogan <[email protected]>2019-01-08 00:08:22 -0800
commit7ad28fd1bd0b6504c78c5d76903878cebd5cd631 (patch)
treef883f98ac4c07dc71a1ff167bcb69ac6f18beeaf
parent74a4f7b390581859b798079484f4af2644d41ee2 (diff)
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Revamp get_dss_public_key()
* Simplify logic by having incremental allocation and only free on error on one place. * Add error checking on all OpenSSL calls. * Make it explicit when you need to be careful with non-reference counted pointers. - set0 calls will use the pointer values without ref counting. - On success, set pointers to NULL to avoid double frees since the struct is now responsible for freeing the resources.
-rw-r--r--lib/crypto/c_src/dss.c64
1 files changed, 46 insertions, 18 deletions
diff --git a/lib/crypto/c_src/dss.c b/lib/crypto/c_src/dss.c
index 934b33d87c..9bf8eb3ce0 100644
--- a/lib/crypto/c_src/dss.c
+++ b/lib/crypto/c_src/dss.c
@@ -94,23 +94,51 @@ int get_dss_public_key(ErlNifEnv* env, ERL_NIF_TERM key, DSA *dsa)
ERL_NIF_TERM head, tail;
BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL, *dsa_y = NULL;
- if (!enif_get_list_cell(env, key, &head, &tail)
- || !get_bn_from_bin(env, head, &dsa_p)
- || !enif_get_list_cell(env, tail, &head, &tail)
- || !get_bn_from_bin(env, head, &dsa_q)
- || !enif_get_list_cell(env, tail, &head, &tail)
- || !get_bn_from_bin(env, head, &dsa_g)
- || !enif_get_list_cell(env, tail, &head, &tail)
- || !get_bn_from_bin(env, head, &dsa_y)
- || !enif_is_empty_list(env,tail)) {
- if (dsa_p) BN_free(dsa_p);
- if (dsa_q) BN_free(dsa_q);
- if (dsa_g) BN_free(dsa_g);
- if (dsa_y) BN_free(dsa_y);
- return 0;
- }
-
- DSA_set0_pqg(dsa, dsa_p, dsa_q, dsa_g);
- DSA_set0_key(dsa, dsa_y, NULL);
+ if (!enif_get_list_cell(env, key, &head, &tail))
+ goto err;
+ if (!get_bn_from_bin(env, head, &dsa_p))
+ goto err;
+
+ if (!enif_get_list_cell(env, tail, &head, &tail))
+ goto err;
+ if (!get_bn_from_bin(env, head, &dsa_q))
+ goto err;
+
+ if (!enif_get_list_cell(env, tail, &head, &tail))
+ goto err;
+ if (!get_bn_from_bin(env, head, &dsa_g))
+ goto err;
+
+ if (!enif_get_list_cell(env, tail, &head, &tail))
+ goto err;
+ if (!get_bn_from_bin(env, head, &dsa_y))
+ goto err;
+
+ if (!enif_is_empty_list(env,tail))
+ goto err;
+
+ if (!DSA_set0_pqg(dsa, dsa_p, dsa_q, dsa_g))
+ goto err;
+ /* dsa takes ownership on success */
+ dsa_p = NULL;
+ dsa_q = NULL;
+ dsa_g = NULL;
+
+ if (!DSA_set0_key(dsa, dsa_y, NULL))
+ goto err;
+ /* dsa takes ownership on success */
+ dsa_y = NULL;
+
return 1;
+
+ err:
+ if (dsa_p)
+ BN_free(dsa_p);
+ if (dsa_q)
+ BN_free(dsa_q);
+ if (dsa_g)
+ BN_free(dsa_g);
+ if (dsa_y)
+ BN_free(dsa_y);
+ return 0;
}