tpm2: Check return code of BN_div()

Resolves: #304 Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
stefanberger · Mar 30, 2022 · ffaaeb0 · ffaaeb0
1 parent bd42b67
commit ffaaeb0
Showing 1 changed file with 1 addition and 2 deletions.
diff --git a/src/tpm2/crypto/openssl/Helpers.c b/src/tpm2/crypto/openssl/Helpers.c
@@ -521,8 +521,7 @@ InitOpenSSLRSAPrivateKey(OBJECT     *rsaKey,   // IN
             ERROR_RETURN(TPM_RC_FAILURE);
         /* Q = N/P; no remainder */
         BN_set_flags(P, BN_FLG_CONSTTIME); // P is secret
-        BN_div(Q, Qr, N, P, ctx);
-        if(!BN_is_zero(Qr))
+        if (!BN_div(Q, Qr, N, P, ctx) || !BN_is_zero(Qr))
             ERROR_RETURN(TPM_RC_BINDING);
         BN_set_flags(Q, BN_FLG_CONSTTIME); // Q is secret