Fix incorrect error branch in ossl_bn_rsa_fips186_4_derive_prime() #20279
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BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1 on success. In case of failure, the algorithm should fail. However, the branch that it goes through on failure is "goto end", not "goto err". Therefore, the algorithm will return 1 which indicates success instead of 0 for failure, leading to potential problems for the callers. Fix it by changing the goto to "goto err" instead of "goto end". CLA: trivial
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Feb 17, 2023
| @@ -357,7 +357,7 @@ int ossl_bn_rsa_fips186_4_derive_prime(BIGNUM *Y, BIGNUM *X, const BIGNUM *Xin, | |||
| * sqrt(2) * 2^(nlen/2-1) <= Random X <= (2^(nlen/2)) - 1. | |||
| */ | |||
| if (!BN_priv_rand_range_ex(X, range, 0, ctx) || !BN_add(X, X, base)) | |||
| goto end; | |||
| goto err; | |||
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Good catch,,
Not sure if it is possible in practice.. BN_priv_rand_range_ex() does 100 iterations so it would have a very very small probability that this could ever fail.
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Feb 20, 2023
BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1 on success. In case of failure, the algorithm should fail. However, the branch that it goes through on failure is "goto end", not "goto err". Therefore, the algorithm will return 1 which indicates success instead of 0 for failure, leading to potential problems for the callers. Fix it by changing the goto to "goto err" instead of "goto end". CLA: trivial Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Shane Lontis <shane.lontis@oracle.com> Reviewed-by: Todd Short <todd.short@me.com> (Merged from #20279)
openssl-machine
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Feb 20, 2023
BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1 on success. In case of failure, the algorithm should fail. However, the branch that it goes through on failure is "goto end", not "goto err". Therefore, the algorithm will return 1 which indicates success instead of 0 for failure, leading to potential problems for the callers. Fix it by changing the goto to "goto err" instead of "goto end". CLA: trivial Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Shane Lontis <shane.lontis@oracle.com> Reviewed-by: Todd Short <todd.short@me.com> (Merged from #20279) (cherry picked from commit 835b90a)
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Merged to master, openssl-3.1 and openssl-3.0. Thanks for your contribution! |
openssl-machine
pushed a commit
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Feb 20, 2023
BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1 on success. In case of failure, the algorithm should fail. However, the branch that it goes through on failure is "goto end", not "goto err". Therefore, the algorithm will return 1 which indicates success instead of 0 for failure, leading to potential problems for the callers. Fix it by changing the goto to "goto err" instead of "goto end". CLA: trivial Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Shane Lontis <shane.lontis@oracle.com> Reviewed-by: Todd Short <todd.short@me.com> (Merged from #20279) (cherry picked from commit 835b90a) (cherry picked from commit d1e1a8f)
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BN_priv_rand_range_ex() and BN_add() both return a 0 on failure and a 1 on success. In case of failure, the algorithm should fail. However, the branch that it goes through on failure is "goto end", not "goto err". Therefore, the algorithm will return 1 which indicates success instead of 0 for failure, leading to potential problems for the callers. Fix it by changing the goto to "goto err" instead of "goto end".
CLA: trivial
Please note that I found this using a static analysis tool I am developing at the moment. It could therefore be a false positive bug. I manually reviewed the case to be extra sure that it is a real bug.
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