From 299bd4f113d0bd39fa1577a671a04ed7899eff3c Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Sun, 31 May 2020 12:39:14 +0200 Subject: [PATCH 1/3] _gnutls_pkcs11_verify_crt_status: check validity against system cert To verify a certificate chain, this function replaces known certificates with the ones in the system trust store if possible. However, if it is found, the function checks the validity of the original certificate rather than the certificate found in the trust store. That reveals a problem in a scenario that (1) a certificate is signed by multiple issuers and (2) one of the issuers' certificate has expired and included in the input chain. This patch makes it a little robuster by actually retrieving the certificate from the trust store and perform check against it. Signed-off-by: Daiki Ueno --- lib/pkcs11.c | 98 +++++++++++++++++++++++++++++++++-------------- lib/pkcs11_int.h | 5 +++ lib/x509/verify.c | 7 +++- 3 files changed, 80 insertions(+), 30 deletions(-) diff --git a/lib/pkcs11.c b/lib/pkcs11.c index fad16aaf4f..d8d4a65114 100644 --- a/lib/pkcs11.c +++ b/lib/pkcs11.c @@ -4547,34 +4547,10 @@ int gnutls_pkcs11_get_raw_issuer_by_subject_key_id (const char *url, return ret; } -/** - * gnutls_pkcs11_crt_is_known: - * @url: A PKCS 11 url identifying a token - * @cert: is the certificate to find issuer for - * @issuer: Will hold the issuer if any in an allocated buffer. - * @fmt: The format of the exported issuer. - * @flags: Use zero or flags from %GNUTLS_PKCS11_OBJ_FLAG. - * - * This function will check whether the provided certificate is stored - * in the specified token. This is useful in combination with - * %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED or - * %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED, - * to check whether a CA is present or a certificate is blacklisted in - * a trust PKCS #11 module. - * - * This function can be used with a @url of "pkcs11:", and in that case all modules - * will be searched. To restrict the modules to the marked as trusted in p11-kit - * use the %GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE flag. - * - * Note that the flag %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED is - * specific to p11-kit trust modules. - * - * Returns: If the certificate exists non-zero is returned, otherwise zero. - * - * Since: 3.3.0 - **/ -unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, - unsigned int flags) +unsigned +_gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, + unsigned int flags, + gnutls_x509_crt_t *trusted_cert) { int ret; struct find_cert_st priv; @@ -4586,6 +4562,15 @@ unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, memset(&priv, 0, sizeof(priv)); + if (trusted_cert) { + ret = gnutls_pkcs11_obj_init(&priv.obj); + if (ret < 0) { + gnutls_assert(); + goto cleanup; + } + priv.need_import = 1; + } + if (url == NULL || url[0] == 0) { url = "pkcs11:"; } @@ -4632,8 +4617,18 @@ unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, _gnutls_debug_log("crt_is_known: did not find cert, using issuer DN + serial, using DN only\n"); /* attempt searching with the subject DN only */ gnutls_assert(); + if (priv.obj) + gnutls_pkcs11_obj_deinit(priv.obj); gnutls_free(priv.serial.data); memset(&priv, 0, sizeof(priv)); + if (trusted_cert) { + ret = gnutls_pkcs11_obj_init(&priv.obj); + if (ret < 0) { + gnutls_assert(); + goto cleanup; + } + priv.need_import = 1; + } priv.crt = cert; priv.flags = flags; @@ -4650,9 +4645,26 @@ unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, goto cleanup; } + if (trusted_cert) { + ret = gnutls_x509_crt_init(trusted_cert); + if (ret < 0) { + gnutls_assert(); + ret = 0; + goto cleanup; + } + ret = gnutls_x509_crt_import_pkcs11(*trusted_cert, priv.obj); + if (ret < 0) { + gnutls_assert(); + gnutls_x509_crt_deinit(*trusted_cert); + ret = 0; + goto cleanup; + } + } ret = 1; cleanup: + if (priv.obj) + gnutls_pkcs11_obj_deinit(priv.obj); if (info) p11_kit_uri_free(info); gnutls_free(priv.serial.data); @@ -4660,6 +4672,36 @@ unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, return ret; } +/** + * gnutls_pkcs11_crt_is_known: + * @url: A PKCS 11 url identifying a token + * @cert: is the certificate to find issuer for + * @flags: Use zero or flags from %GNUTLS_PKCS11_OBJ_FLAG. + * + * This function will check whether the provided certificate is stored + * in the specified token. This is useful in combination with + * %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED or + * %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED, + * to check whether a CA is present or a certificate is blacklisted in + * a trust PKCS #11 module. + * + * This function can be used with a @url of "pkcs11:", and in that case all modules + * will be searched. To restrict the modules to the marked as trusted in p11-kit + * use the %GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE flag. + * + * Note that the flag %GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED is + * specific to p11-kit trust modules. + * + * Returns: If the certificate exists non-zero is returned, otherwise zero. + * + * Since: 3.3.0 + **/ +unsigned gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, + unsigned int flags) +{ + return _gnutls_pkcs11_crt_is_known(url, cert, flags, NULL); +} + /** * gnutls_pkcs11_obj_get_flags: * @obj: The pkcs11 object diff --git a/lib/pkcs11_int.h b/lib/pkcs11_int.h index 9d88807098..86cce0dee5 100644 --- a/lib/pkcs11_int.h +++ b/lib/pkcs11_int.h @@ -460,6 +460,11 @@ inline static bool is_pkcs11_url_object(const char *url) return 0; } +unsigned +_gnutls_pkcs11_crt_is_known(const char *url, gnutls_x509_crt_t cert, + unsigned int flags, + gnutls_x509_crt_t *trusted_cert); + #endif /* ENABLE_PKCS11 */ #endif /* GNUTLS_LIB_PKCS11_INT_H */ diff --git a/lib/x509/verify.c b/lib/x509/verify.c index d202670198..fd7c6a1642 100644 --- a/lib/x509/verify.c +++ b/lib/x509/verify.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include #include @@ -1188,6 +1189,7 @@ _gnutls_pkcs11_verify_crt_status(const char* url, for (; i < clist_size; i++) { unsigned vflags; + gnutls_x509_crt_t trusted_cert; if (i == 0) /* in the end certificate do full comparison */ vflags = GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE| @@ -1196,9 +1198,10 @@ _gnutls_pkcs11_verify_crt_status(const char* url, vflags = GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE| GNUTLS_PKCS11_OBJ_FLAG_COMPARE_KEY|GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED; - if (gnutls_pkcs11_crt_is_known (url, certificate_list[i], vflags) != 0) { + if (_gnutls_pkcs11_crt_is_known (url, certificate_list[i], vflags, &trusted_cert) != 0) { - status |= check_ca_sanity(certificate_list[i], now, flags); + status |= check_ca_sanity(trusted_cert, now, flags); + gnutls_x509_crt_deinit(trusted_cert); if (func) func(certificate_list[i], -- 2.26.2 From cdf075e7f54cb77f046ef3e7c2147f159941faca Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Sun, 31 May 2020 13:59:53 +0200 Subject: [PATCH 2/3] x509: trigger fallback verification path when cert is expired gnutls_x509_trust_list_verify_crt2 use the macro SIGNER_OLD_OR_UNKNOWN to trigger the fallback verification path if the signer of the last certificate is not in the trust store. Previously, it doesn't take into account of the condition where the certificate is expired. Signed-off-by: Daiki Ueno --- lib/x509/verify-high.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/lib/x509/verify-high.c b/lib/x509/verify-high.c index b1421ef17a..40638ad3aa 100644 --- a/lib/x509/verify-high.c +++ b/lib/x509/verify-high.c @@ -1192,11 +1192,13 @@ gnutls_x509_trust_list_verify_crt(gnutls_x509_trust_list_t list, #define LAST_DN cert_list[cert_list_size-1]->raw_dn #define LAST_IDN cert_list[cert_list_size-1]->raw_issuer_dn -/* This macro is introduced to detect a verification output - * which indicates an unknown signer, or a signer which uses - * an insecure algorithm (e.g., sha1), something that indicates - * a superseded signer */ -#define SIGNER_OLD_OR_UNKNOWN(output) ((output & GNUTLS_CERT_SIGNER_NOT_FOUND) || (output & GNUTLS_CERT_INSECURE_ALGORITHM)) +/* This macro is introduced to detect a verification output which + * indicates an unknown signer, a signer which uses an insecure + * algorithm (e.g., sha1), a signer has expired, or something that + * indicates a superseded signer */ +#define SIGNER_OLD_OR_UNKNOWN(output) ((output & GNUTLS_CERT_SIGNER_NOT_FOUND) || \ + (output & GNUTLS_CERT_EXPIRED) || \ + (output & GNUTLS_CERT_INSECURE_ALGORITHM)) #define SIGNER_WAS_KNOWN(output) (!(output & GNUTLS_CERT_SIGNER_NOT_FOUND)) /** -- 2.26.2 From 9067bcbee8ff18badff1e829d22e63590dbd7a5c Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Sun, 31 May 2020 14:28:48 +0200 Subject: [PATCH 3/3] tests: add test case for certificate chain superseding Signed-off-by: Daiki Ueno --- tests/test-chains.h | 97 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) diff --git a/tests/test-chains.h b/tests/test-chains.h index dd19e6a815..9b06b85f5f 100644 --- a/tests/test-chains.h +++ b/tests/test-chains.h @@ -4010,6 +4010,102 @@ static const char *ed448[] = { NULL }; +/* This contains an expired intermediate CA, which should be superseded. */ +static const char *superseding[] = { + "-----BEGIN CERTIFICATE-----" + "MIIDrzCCAmegAwIBAgIUcozIBhMJvM/rd1PVI7LOq7Kscs8wDQYJKoZIhvcNAQEL" + "BQAwJjEkMCIGA1UEAxMbR251VExTIHRlc3QgaW50ZXJtZWRpYXRlIENBMCAXDTIw" + "MDUzMTEyMTczN1oYDzk5OTkxMjMxMjM1OTU5WjA3MRgwFgYDVQQDEw90ZXN0Lmdu" + "dXRscy5vcmcxGzAZBgNVBAoTEkdudVRMUyB0ZXN0IHNlcnZlcjCCASAwCwYJKoZI" + "hvcNAQEKA4IBDwAwggEKAoIBAQCd2PBnWn+b0FsIMbG+f/K+og2iK/BoLCsJD3j9" + "yRNSHD6wTifYwNTbe1LF/8BzxcwVRCD0zpbpFQawbjxbmBSzrXqQlUFFG11DvNBa" + "w58rgHGo3TYCrtFIBfLbziyB1w/vWeX0xHvv8MMJ1iRSdY+7Y36a2cV+s85PdO4B" + "TpZlLfy8LPP6p6+dgVoC+9tTu2H1wARYOVog+jt9A3Hx0L1xxVWTedFoiK2sVouz" + "fLRjfp5cOwuRHSD2qbpGOAeNVVaOE88Bv3pIGPguMw0qAdEDo20hRYH23LIyvBwB" + "oCnyFNnAViMtLa2QlXSliV9a9BKOXYjWzAeso2SF4pdHcvd5AgMBAAGjgZMwgZAw" + "DAYDVR0TAQH/BAIwADAaBgNVHREEEzARgg90ZXN0LmdudXRscy5vcmcwEwYDVR0l" + "BAwwCgYIKwYBBQUHAwEwDwYDVR0PAQH/BAUDAweAADAdBgNVHQ4EFgQUan6mlccq" + "Uy1Z64wvRv3xxg4h2ykwHwYDVR0jBBgwFoAUSCM0UwqJMThKWurKttKm3s4dKxgw" + "DQYJKoZIhvcNAQELBQADggExAKAOMyMLpk0u2UTwwFWtr1hfx7evo2J7dgco410I" + "DN/QWoe2Xlcxcp1h5R9rX1I3KU2WGFtdXqiMsllCLnrDEKZmlks0uz76bCpKmM99" + "/1MDlY7mGCr/2PPx53USK5J5JTiqgp6r7qAcDAnpYvrPH45kk7iqwh02DhAxRnGR" + "CW7KWK8h7uu0Az9iBT2YfV372g4fRDK3fqYzJofQwbhSiUuJ7wyZCRhGOoxMMmDb" + "KBbc1wAYXW+tlv2cSbfzRvSxMR+CzkyH2tGDxeN//aZUfGmQ8IzWUQ7UtK5z+Q0E" + "fL6fZtm2SdGabGpV1UYoGpwOtOngK+m0i9SqrMD7g5+SMhc1VuvVuTtxjr5Cha8l" + "X0HEZtxgFrkdfMD4yLAqiguaCBngtbRmELF5VpebmJbiLVU=" + "-----END CERTIFICATE-----", + "-----BEGIN CERTIFICATE-----" + "MIIDkTCCAkmgAwIBAgIUY9cJ4NLNFEaojJHdP1I4Q7OHNJwwDQYJKoZIhvcNAQEL" + "BQAwGTEXMBUGA1UEAxMOR251VExTIHRlc3QgQ0EwHhcNMTgxMjMxMjMwMDAwWhcN" + "MjAwNTMwMjIwMDAwWjAmMSQwIgYDVQQDExtHbnVUTFMgdGVzdCBpbnRlcm1lZGlh" + "dGUgQ0EwggFSMA0GCSqGSIb3DQEBAQUAA4IBPwAwggE6AoIBMQC0ayeYJa/B/x7K" + "sH702LztQ4ZnVF3atB7CkF+DPAIR/BNyhbKIpGVBC3ZfI76Kn/55S3M7LsdLPL8W" + "yZdVNRfzoXJLMMLgJ5QS81YA5s6CSxFdpB6b+vq5GypNGLW6peYMx6iooW2qiITc" + "lg6ybBw1qufHlD351cfCog1Ls2569whfxQnNFZMa95jfKkxmiSTtH9AWY4FlpVg7" + "oc0lYpuZgVQIFxjsfC8IojsoVzKdF0cKhvtisUGZ5vveqOogfvMb7rrqmiFkKZLy" + "rXPlGQWdN1PiEZ8YXyK64osNAIyeL6eHPUC+SqKlkggMLmHAWHyameHWrIM5Jc8+" + "G+3ro22dy8U43sHHbps0FL4wPoKQHrlKmnbk7zMMRqIxcvbDYQv4qmeJ9KXldjeh" + "KZ+Aeap1AgMBAAGjZDBiMA8GA1UdEwEB/wQFMAMBAf8wDwYDVR0PAQH/BAUDAwcE" + "ADAdBgNVHQ4EFgQUSCM0UwqJMThKWurKttKm3s4dKxgwHwYDVR0jBBgwFoAUHncj" + "bWcxH5EHm5Yv7PzIRv6M4QMwDQYJKoZIhvcNAQELBQADggExAHP1UAQ/nvuQtRZF" + "Q4b96yxVwCjMjn7knLyLNtyYGE3466xvE/ofvx5lgaR06ez/G17XP+Ok5SLJNUVc" + "mplTERCv5CgnX7R5VdGJkkD1repaYxaTtwyJz0AfYEMRUj3jfaeLaiUKJvEW5RRs" + "I3solY18sy/m/xGrH2X0GTNfKM9BURENABsppt07jxH719nF9m9SynV/Z2hE5hlv" + "5e5vyPt4wyRPIJLUI3TKAlvb1s40zz3ua7ZTgQL/cOxfY4f9pRKW9CMB3uF69OP9" + "COAxrmHVZsImmDZ6qO1qQrbY1KN/cX5kG4pKg7Ium723aOlwcWzEDXKumD960fN1" + "5g+HrjNs6kW+r9Q5QS8qV5s8maZNcxTrMvQ1fF2AKBNI3Z3U7vmtrSeqxIXp3rGH" + "iJwOKIk=" + "-----END CERTIFICATE-----", + NULL +}; + +static const char *superseding_ca[] = { + "-----BEGIN CERTIFICATE-----" + "MIIDkzCCAkugAwIBAgIUIs7jB4Q4sFcdCmzWVHbJLESC3T4wDQYJKoZIhvcNAQEL" + "BQAwGTEXMBUGA1UEAxMOR251VExTIHRlc3QgQ0EwIBcNMjAwNTMxMTIxMzEwWhgP" + "OTk5OTEyMzEyMzU5NTlaMCYxJDAiBgNVBAMTG0dudVRMUyB0ZXN0IGludGVybWVk" + "aWF0ZSBDQTCCAVIwDQYJKoZIhvcNAQEBBQADggE/ADCCAToCggExALRrJ5glr8H/" + "HsqwfvTYvO1DhmdUXdq0HsKQX4M8AhH8E3KFsoikZUELdl8jvoqf/nlLczsux0s8" + "vxbJl1U1F/OhckswwuAnlBLzVgDmzoJLEV2kHpv6+rkbKk0Ytbql5gzHqKihbaqI" + "hNyWDrJsHDWq58eUPfnVx8KiDUuzbnr3CF/FCc0Vkxr3mN8qTGaJJO0f0BZjgWWl" + "WDuhzSVim5mBVAgXGOx8LwiiOyhXMp0XRwqG+2KxQZnm+96o6iB+8xvuuuqaIWQp" + "kvKtc+UZBZ03U+IRnxhfIrriiw0AjJ4vp4c9QL5KoqWSCAwuYcBYfJqZ4dasgzkl" + "zz4b7eujbZ3LxTjewcdumzQUvjA+gpAeuUqaduTvMwxGojFy9sNhC/iqZ4n0peV2" + "N6Epn4B5qnUCAwEAAaNkMGIwDwYDVR0TAQH/BAUwAwEB/zAPBgNVHQ8BAf8EBQMD" + "BwQAMB0GA1UdDgQWBBRIIzRTCokxOEpa6sq20qbezh0rGDAfBgNVHSMEGDAWgBQe" + "dyNtZzEfkQebli/s/MhG/ozhAzANBgkqhkiG9w0BAQsFAAOCATEAcF9R9VGQxTwW" + "aOjeIeQ9ZJxybaj0BaXC8xR4b9uZloS9d/RBFTjgRbQ82yqaj7f80mgUtabKRfTA" + "ltV2MgTbJdOjwGzEDtKGhClBbovnEGrYTbPBT9rgfYPt0q7SMBr6AzGAPt+ltwI7" + "9yntV81qvTxvW5MEEo0j2MuA3NT3oqe+w1rUKNQCWhnN2TUhJGkTlaaMozcgNFaE" + "Dplop4dtvCGtupxOjC3Nf6FWq1k7iZQxX70AFBYVMpuF7qGh6qDp+T1hmTCSVzxP" + "SfDQIBjhKgy4clhkuR5SRxhN74RX+/5eiQyVLxzr+eIhqzJhPqUCmVnCLcqYdNRi" + "hpHic4uJm0wGOKYTI7EG8rb4ZP4Jz6k4iN9CnL/+kiiW5otSl3YyCAuao5VKdDq9" + "izchzb9eow==" + "-----END CERTIFICATE-----", + "-----BEGIN CERTIFICATE-----" + "MIIDZTCCAh2gAwIBAgIULcrECQOBgPaePBfBHXcyZiU0IiYwDQYJKoZIhvcNAQEL" + "BQAwGTEXMBUGA1UEAxMOR251VExTIHRlc3QgQ0EwIBcNMjAwNTMxMTIxMTQzWhgP" + "OTk5OTEyMzEyMzU5NTlaMBkxFzAVBgNVBAMTDkdudVRMUyB0ZXN0IENBMIIBUjAN" + "BgkqhkiG9w0BAQEFAAOCAT8AMIIBOgKCATEAnORCsX1unl//fy2d1054XduIg/3C" + "qVBaT3Hca65SEoDwh0KiPtQoOgZLdKY2cobGs/ojYtOjcs0KnlPYdmtjEh6WEhuJ" + "U95v4TQdC4OLMiE56eIGq252hZAbHoTL84Q14DxQWGuzQK830iml7fbw2WcIcRQ8" + "vFGs8SzfXw63+MI6Fq6iMAQIqP08WzGmRRzL5wvCiPhCVkrPmwbXoABub6AAsYwW" + "PJB91M9/lx5gFH5k9/iPfi3s2Kg3F8MOcppqFYjxDSnsfiz6eMh1+bYVIAo367vG" + "VYHigXMEZC2FezlwIHaZzpEoFlY3a7LFJ00yrjQ910r8UE+CEMTYzE40D0olCMo7" + "FA9RCjeO3bUIoYaIdVTUGWEGHWSeoxGei9Gkm6u+ASj8f+i0jxdD2qXsewIDAQAB" + "o0MwQTAPBgNVHRMBAf8EBTADAQH/MA8GA1UdDwEB/wQFAwMHBAAwHQYDVR0OBBYE" + "FB53I21nMR+RB5uWL+z8yEb+jOEDMA0GCSqGSIb3DQEBCwUAA4IBMQAeMSzMyuTy" + "FjXTjxAUv010bsr6e6fI9txq/S1tXmWWJV/8aeARthuOFZO5Jjy3C5aMbac2HDV4" + "Otu0+JLaoEMSXvorAhValVuq06i5cmaPzvJBcxMWzlEAXfavSwHv5Q+kqNU3z81S" + "WnjEpMHcl9OyER7o9IhF55Xom2BXY5XL83QOzQ4C3bpKrNevZC7i7zS8NoYRGP+8" + "w21JseXkWQW4o2hkFqbCcRE1dlMW02iJE28RZ5aBFDIm2Y6zuLaXZIkaO7E41CAw" + "IUyhowm/S1HcmQnhruAGKJvQtB6jvnhZb7pgnuSkhIvAQgw93CLE985KEua1ifY2" + "p1d/6ho2TWotHHqDnDkB8pC0Wzai8R+63z18Kt0gROX2QItCyFksjNJqYPbgwZgt" + "eh1COrLsOJo+" + "-----END CERTIFICATE-----", + NULL +}; + #if defined __clang__ || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wunused-variable" @@ -4178,6 +4274,7 @@ static struct GNUTLS_CERT_INSECURE_ALGORITHM | GNUTLS_CERT_INVALID, NULL, 1576759855, 1}, { "ed448 - ok", ed448, &ed448[0], GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_ULTRA), 0, NULL, 1584352960, 1}, + { "superseding - ok", superseding, superseding_ca, 0, 0, 0, 1590928011 }, { NULL, NULL, NULL, 0, 0} }; -- 2.26.2