From 18c02492138d1eb8b6548cb26e7b625fb2414a2a Mon Sep 17 00:00:00 2001 From: Tomas Mraz Date: Fri, 22 Dec 2023 16:25:56 +0100 Subject: [PATCH] Limit the execution time of RSA public key check Fixes CVE-2023-6237 If a large and incorrect RSA public key is checked with EVP_PKEY_public_check() the computation could take very long time due to no limit being applied to the RSA public key size and unnecessarily high number of Miller-Rabin algorithm rounds used for non-primality check of the modulus. Now the keys larger than 16384 bits (OPENSSL_RSA_MAX_MODULUS_BITS) will fail the check with RSA_R_MODULUS_TOO_LARGE error reason. Also the number of Miller-Rabin rounds was set to 5. Reviewed-by: Neil Horman Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/23243) (cherry picked from commit e09fc1d746a4fd15bb5c3d7bbbab950aadd005db) --- crypto/rsa/rsa_sp800_56b_check.c | 8 +++- test/recipes/91-test_pkey_check.t | 2 +- .../91-test_pkey_check_data/rsapub_17k.pem | 48 +++++++++++++++++++ 3 files changed, 56 insertions(+), 2 deletions(-) create mode 100644 test/recipes/91-test_pkey_check_data/rsapub_17k.pem diff --git a/crypto/rsa/rsa_sp800_56b_check.c b/crypto/rsa/rsa_sp800_56b_check.c index fc8f19b48770b..bcbdd24fb8199 100644 --- a/crypto/rsa/rsa_sp800_56b_check.c +++ b/crypto/rsa/rsa_sp800_56b_check.c @@ -289,6 +289,11 @@ int ossl_rsa_sp800_56b_check_public(const RSA *rsa) return 0; nbits = BN_num_bits(rsa->n); + if (nbits > OPENSSL_RSA_MAX_MODULUS_BITS) { + ERR_raise(ERR_LIB_RSA, RSA_R_MODULUS_TOO_LARGE); + return 0; + } + #ifdef FIPS_MODULE /* * (Step a): modulus must be 2048 or 3072 (caveat from SP800-56Br1) @@ -324,7 +329,8 @@ int ossl_rsa_sp800_56b_check_public(const RSA *rsa) goto err; } - ret = ossl_bn_miller_rabin_is_prime(rsa->n, 0, ctx, NULL, 1, &status); + /* Highest number of MR rounds from FIPS 186-5 Section B.3 Table B.1 */ + ret = ossl_bn_miller_rabin_is_prime(rsa->n, 5, ctx, NULL, 1, &status); #ifdef FIPS_MODULE if (ret != 1 || status != BN_PRIMETEST_COMPOSITE_NOT_POWER_OF_PRIME) { #else diff --git a/test/recipes/91-test_pkey_check.t b/test/recipes/91-test_pkey_check.t index dc7cc64533af2..f8088df14d36c 100644 --- a/test/recipes/91-test_pkey_check.t +++ b/test/recipes/91-test_pkey_check.t @@ -70,7 +70,7 @@ push(@positive_tests, ( "dhpkey.pem" )) unless disabled("dh"); -my @negative_pubtests = (); +my @negative_pubtests = ("rsapub_17k.pem"); # Too big RSA public key push(@negative_pubtests, ( "dsapub_noparam.der" diff --git a/test/recipes/91-test_pkey_check_data/rsapub_17k.pem b/test/recipes/91-test_pkey_check_data/rsapub_17k.pem new file mode 100644 index 0000000000000..9a2eaedaf1b22 --- /dev/null +++ b/test/recipes/91-test_pkey_check_data/rsapub_17k.pem @@ -0,0 +1,48 @@ +-----BEGIN PUBLIC KEY----- +MIIIbzANBgkqhkiG9w0BAQEFAAOCCFwAMIIIVwKCCE4Ang+cE5H+hg3RbapDAHqR +B9lUnp2MlAwsZxQ/FhYepaR60bFQeumbu7817Eo5YLMObVI99hF1C4u/qcpD4Jph +gZt87/JAYDbP+DIh/5gUXCL9m5Fp4u7mvZaZdnlcftBvR1uKUTCAwc9pZ/Cfr8W2 +GzrRODzsNYnk2DcZMfe2vRDuDZRopE+Y+I72rom2SZLxoN547N1daM/M/CL9KVQ/ +XMI/YOpJrBI0jI3brMRhLkvLckwies9joufydlGbJkeil9H7/grj3fQZtFkZ2Pkj +b87XDzRVX7wsEpAgPJxskL3jApokCp1kQYKG+Uc3dKM9Ade6IAPK7VKcmbAQTYw2 +gZxsc28dtstazmfGz0ACCTSMrmbgWAM3oPL7RRzhrXDWgmYQ0jHefGh8SNTIgtPq +TuHxPYkDMQNaf0LmDGCxqlnf4b5ld3YaU8zZ/RqIRx5v/+w0rJUvU53qY1bYSnL1 +vbqKSnN2mip0GYyQ4AUgkS1NBV4rGYU/VTvzEjLfkg02KOtHKandvEoUjmZPzCT0 +V2ZhGc8K1UJNGYlIiHqCdwCBoghvly/pYajTkDXyd6BsukzA5H3IkZB1xDgl035j +/0Cr7QeZLEOdi9fPdSSaBT6OmD0WFuZfJF0wMr7ucRhWzPXvSensD9v7MBE7tNfH +SLeTSx8tLt8UeWriiM+0CnkPR1IOqMOxubOyf1eV8NQqEWm5wEQG/0IskbOKnaHa +PqLFJZn/bvyL3XK5OxVIJG3z6bnRDOMS9SzkjqgPdIO8tkySEHVSi/6iuGUltx3Y +Fmq6ye/r34ekyHPbfn6UuTON7joM6SIXb5bHM64x4iMVWx4hMvDjfy0UqfywAUyu +C1o7BExSMxxFG8GJcqR0K8akpPp7EM588PC+YuItoxzXgfUJnP3BQ1Beev2Ve7/J +xeGZH0N4ntfr+cuaLAakAER9zDglwChWflw3NNFgIdAgSxXv3XXx5xDXpdP4lxUo +F5zAN4Mero3yV90FaJl7Vhq/UFVidbwFc15jUDwaE0mKRcsBeVd3GOhoECAgE0id +aIPT20z8oVY0FyTJlRk7QSjo8WjJSrHY/Fn14gctX07ZdfkufyL6w+NijBdYluvB +nIrgHEvpkDEWoIa8qcx0EppoIcmqgMV2mTShfFYSybsO33Pm8WXec2FXjwhzs1Pi +R/BuIW8rHPI67xqWm0h8dEw11vtfi9a/BBBikFHe59KBjMTG+lW/gADNvRoTzGh7 +kN4+UVDS3jlSisRZZOn1XoeQtpubNYWgUsecjKy45IwIj8h1SHgn3wkmUesY0woN +mOdoNtq+NezN4RFtbCOHhxFVpKKDi/HQP2ro0ykkXMDjwEIVf2Lii1Mg9UP8m+Ux +AOqkTrIkdogkRx+70h7/wUOfDIFUq2JbKzqxJYamyEphcdAko7/B8efQKc61Z93O +f2SHa4++4WI7wIIx18v5KV4M/cRmrfc8w9WRkQN3gBT5AJMuqwcSHVXBWvNQeGmi +ScMh7X6cCZ0daEujqb8svq4WgsJ8UT4GaGBRIYtt7QUKEh+JQwNJzneRYZ3pzpaH +UJeeoYobMlkp3rM9cYzdq90nBQiI9Jsbim9m9ggb2dMOS5CsI9S/IuG2O5uTjfxx +wkwsd5nLDFtNXHYZ7W6XlVJ1Rc6zShnEmdCn3mmibb6OaMUmun2yl9ryEjVSoXLP +fSA8W9K9yNhKTRkzdXJfqlC+s/ovX2xBGxsuOoUDaXhRVz0qmpKIHeSFjIP4iXq4 +y8gDiwvM3HbZfvVonbg6siPwpn4uvw3hesojk1DKAENS52i6U3uK2fs1ALVxsFNS +Yh914rDu0Q3e4RXVhURaYzoEbLCot6WGYeCCfQOK0rkETMv+sTYYscC8/THuW7SL +HG5zy9Ed95N1Xmf8J+My7gM7ZFodGdHsWvdzEmqsdOFh6IVx/VfHFX0MDBq0t6lZ +eRvVgVCfu3gkYLwPScn/04E02vOom51ISKHsF/I11erC66jjNYV9BSpH8O7sAHxZ +EmPT2ZVVRSgivOHdQW/FZ3UZQQhVaVSympo2Eb4yWEMFn84Q8T+9Honj6gnB5PXz +chmeCsOMlcg1mwWwhn0k+OAWEZy7VRUk5Ahp0fBAGJgwBdqrZ3kM356DjUkVBiYq +4eHyvafNKmjf2mnFsI3g2NKRNyl1Lh63wyCFx60yYvBUfXF/W9PFJbD9CiP83kEW +gV36gxTsbOSfhpO1OXR90ODy0kx06XzWmJCUugK8u9bx4F/CjV+LIHExuNJiethC +A8sIup/MT0fWp4RO/SsVblGqfoqJTaPnhptQzeH2N07pbWkxeMuL6ppPuwFmfVjK +FJndqCVrAukcPEOQ16iVURuloJMudqYRc9QKkJFsnv0W/iMNbqQGmXe8Q/5qFiys +26NIQBiE2ad9hNLnoccEnmYSRgnW3ZPSKuq5TDdYyDqTZH2r8cam65pr3beKw2XC +xw4cc7VaxiwGC2Mg2wRmwwPaTjrcEt6sMa3RjwFEVBxBFyM26wnTEZsTBquCxV0J +pgERaeplkixP2Q0m7XAdlDaob973SM2vOoUgypzDchWmpx7u775bnOfU5CihwXl+ +k0i09WZuT8bPmhEAiGCw5sNzMkz1BC2cCZFfJIkE2vc/wXYOrGxBTJo0EKaUFswa +2dnP/u0bn+VksBUM7ywW9LJSXh4mN+tpzdeJtxEObKwX1I0dQxSPWmjd2++wMr9q +Unre5fCrDToy2H7C2VKSpuOCT2/Kv4JDQRWwI4KxQOpn0UknAGNmfBoTtpIZ3LEb +77oBUJdMQD7tQBBLL0a6f1TdK0dHVprWWawJ+gGFMiMQXqAqblHcxFKWuHv9bQID +AQAB +-----END PUBLIC KEY-----