From 9edbdaa84e38b1bfb53a7d72c1de44f8de373405 Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Thu, 11 Jan 2024 15:45:11 +0900 Subject: [PATCH 1/2] x509: detect loop in certificate chain MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There can be a loop in a certificate chain, when multiple CA certificates are cross-signed with each other, such as A → B, B → C, and C → A. Previously, the verification logic was not capable of handling this scenario while sorting the certificates in the chain in _gnutls_sort_clist, resulting in an assertion failure. This patch properly detects such loop and aborts further processing in a graceful manner. Signed-off-by: Daiki Ueno --- lib/x509/common.c | 4 ++ tests/test-chains.h | 125 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 129 insertions(+) --- a/lib/x509/common.c +++ b/lib/x509/common.c @@ -1794,10 +1794,14 @@ unsigned int _gnutls_sort_clist(gnutls_x prev = issuer[prev]; if (prev < 0) { /* no issuer */ break; } + if (insorted[prev]) { /* loop detected */ + break; + } + sorted[i] = clist[prev]; insorted[prev] = 1; } /* append the remaining certs */ --- a/tests/test-chains.h +++ b/tests/test-chains.h @@ -4261,10 +4261,133 @@ static const char *rsa_sha1_not_in_trust "tnYFXKC0Q+QUf38horqG2Mc3/uh8MOm0eYUXwGJOdXYD\n" "-----END CERTIFICATE-----\n", NULL }; +static const char *cross_signed[] = { + /* server (signed by A1) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBqDCCAVqgAwIBAgIUejlil+8DBffazcnMNwyOOP6yCCowBQYDK2VwMBoxGDAW\n" + "BgNVBAMTD0ludGVybWVkaWF0ZSBBMTAgFw0yNDAxMTEwNjI3MjJaGA85OTk5MTIz\n" + "MTIzNTk1OVowNzEbMBkGA1UEChMSR251VExTIHRlc3Qgc2VydmVyMRgwFgYDVQQD\n" + "Ew90ZXN0LmdudXRscy5vcmcwKjAFBgMrZXADIQA1ZVS0PcNeTPQMZ+FuVz82AHrj\n" + "qL5hWEpCDgpG4M4fxaOBkjCBjzAMBgNVHRMBAf8EAjAAMBoGA1UdEQQTMBGCD3Rl\n" + "c3QuZ251dGxzLm9yZzATBgNVHSUEDDAKBggrBgEFBQcDATAOBgNVHQ8BAf8EBAMC\n" + "B4AwHQYDVR0OBBYEFGtEUv+JSt+zPoO3lu0IiObZVoiNMB8GA1UdIwQYMBaAFPnY\n" + "v6Pw0IvKSqIlb6ewHyEAmTA3MAUGAytlcANBAAS2lyc87kH/aOvNKzPjqDwUYxPA\n" + "CfYjyaKea2d0DZLBM5+Bjnj/4aWwTKgVTJzWhLJcLtaSdVHrXqjr9NhEhQ0=\n" + "-----END CERTIFICATE-----\n", + /* A1 (signed by A) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBUjCCAQSgAwIBAgIUe/R+NVp04e74ySw2qgI6KZgFR20wBQYDK2VwMBExDzAN\n" + "BgNVBAMTBlJvb3QgQTAgFw0yNDAxMTEwNjI1MDFaGA85OTk5MTIzMTIzNTk1OVow\n" + "GjEYMBYGA1UEAxMPSW50ZXJtZWRpYXRlIEExMCowBQYDK2VwAyEAlkTNqwz973sy\n" + "u3whMjSiUMs77CZu5YA7Gi5KcakExrKjYzBhMA8GA1UdEwEB/wQFMAMBAf8wDgYD\n" + "VR0PAQH/BAQDAgIEMB0GA1UdDgQWBBT52L+j8NCLykqiJW+nsB8hAJkwNzAfBgNV\n" + "HSMEGDAWgBRbYgOkRGsd3Z74+CauX4htzLg0lzAFBgMrZXADQQBM0NBaFVPd3cTJ\n" + "DSaZNT34fsHuJk4eagpn8mBxKQpghq4s8Ap+nYtp2KiXjcizss53PeLXVnkfyLi0\n" + "TLVBHvUJ\n" + "-----END CERTIFICATE-----\n", + /* A (signed by B) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhQtdJpg+qlPcLoRW8iiztJUD4xNvDAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBCMCAXDTI0MDExMTA2MTk1OVoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEEwKjAFBgMrZXADIQA0vDYyg3tgotSETL1Wq2hBs32p\n" + "WbnINkmOSNmOiZlGHKNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFFtiA6REax3dnvj4Jq5fiG3MuDSXMB8GA1UdIwQYMBaAFJFA\n" + "s2rg6j8w9AKItRnOOOjG2FG6MAUGAytlcANBAPv674p9ek5GjRcRfVQhgN+kQlHU\n" + "u774wL3Vx3fWA1E7+WchdMzcHrPoa5OKtKmxjIKUTO4SeDZL/AVpvulrWwk=\n" + "-----END CERTIFICATE-----\n", + /* A (signed by C) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhReNpCiVn7eFDUox3mvM5qE942AVzAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBDMCAXDTI0MDExMTA2MjEyMVoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEIwKjAFBgMrZXADIQAYX92hS97OGKbMzwrD7ReVifwM\n" + "3iz5tnfQHWQSkvvYMKNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFJFAs2rg6j8w9AKItRnOOOjG2FG6MB8GA1UdIwQYMBaAFEh/\n" + "XKjIuMeEavX5QVoy39Q+GhnwMAUGAytlcANBAIwghH3gelXty8qtoTGIEJb0+EBv\n" + "BH4YOUh7TamxjxkjvvIhDA7ZdheofFb7NrklJco7KBcTATUSOvxakYRP9Q8=\n" + "-----END CERTIFICATE-----\n", + /* B1 (signed by B) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBUjCCAQSgAwIBAgIUfpmrVDc1XBA5/7QYMyGBuB9mTtUwBQYDK2VwMBExDzAN\n" + "BgNVBAMTBlJvb3QgQjAgFw0yNDAxMTEwNjI1MjdaGA85OTk5MTIzMTIzNTk1OVow\n" + "GjEYMBYGA1UEAxMPSW50ZXJtZWRpYXRlIEIxMCowBQYDK2VwAyEAh6ZTuJWsweVB\n" + "a5fsye5iq89kWDC2Y/Hlc0htLmjzMP+jYzBhMA8GA1UdEwEB/wQFMAMBAf8wDgYD\n" + "VR0PAQH/BAQDAgIEMB0GA1UdDgQWBBTMQu37PKyLjKfPODZgxYCaayff+jAfBgNV\n" + "HSMEGDAWgBSRQLNq4Oo/MPQCiLUZzjjoxthRujAFBgMrZXADQQBblmguY+lnYvOK\n" + "rAZJnqpEUGfm1tIFyu3rnlE7WOVcXRXMIoNApLH2iHIipQjlvNWuSBFBTC1qdewh\n" + "/e+0cgQB\n" + "-----END CERTIFICATE-----\n", + /* B (signed by A) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhRpEm+dWNX6DMZh/nottkFfFFrXXDAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBBMCAXDTI0MDExMTA2MTcyNloYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEIwKjAFBgMrZXADIQAYX92hS97OGKbMzwrD7ReVifwM\n" + "3iz5tnfQHWQSkvvYMKNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFJFAs2rg6j8w9AKItRnOOOjG2FG6MB8GA1UdIwQYMBaAFFti\n" + "A6REax3dnvj4Jq5fiG3MuDSXMAUGAytlcANBAFvmcK3Ida5ViVYDzxKVLPcPsCHe\n" + "3hxz99lBrerJC9iJSvRYTJoPBvjTxDYnBn5EFrQYMrUED+6i71lmGXNU9gs=\n" + "-----END CERTIFICATE-----\n", + /* B (signed by C) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhReNpCiVn7eFDUox3mvM5qE942AVzAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBDMCAXDTI0MDExMTA2MjEyMVoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEIwKjAFBgMrZXADIQAYX92hS97OGKbMzwrD7ReVifwM\n" + "3iz5tnfQHWQSkvvYMKNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFJFAs2rg6j8w9AKItRnOOOjG2FG6MB8GA1UdIwQYMBaAFEh/\n" + "XKjIuMeEavX5QVoy39Q+GhnwMAUGAytlcANBAIwghH3gelXty8qtoTGIEJb0+EBv\n" + "BH4YOUh7TamxjxkjvvIhDA7ZdheofFb7NrklJco7KBcTATUSOvxakYRP9Q8=\n" + "-----END CERTIFICATE-----\n", + /* C1 (signed by C) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBUjCCAQSgAwIBAgIUSKsfY1wD3eD2VmaaK1wt5naPckMwBQYDK2VwMBExDzAN\n" + "BgNVBAMTBlJvb3QgQzAgFw0yNDAxMTEwNjI1NDdaGA85OTk5MTIzMTIzNTk1OVow\n" + "GjEYMBYGA1UEAxMPSW50ZXJtZWRpYXRlIEMxMCowBQYDK2VwAyEA/t7i1chZlKkV\n" + "qxJOrmmyATn8XnpK+nV/iT4OMHSHfAyjYzBhMA8GA1UdEwEB/wQFMAMBAf8wDgYD\n" + "VR0PAQH/BAQDAgIEMB0GA1UdDgQWBBRmpF3JjoP3NiBzE5J5ANT0bvfRmjAfBgNV\n" + "HSMEGDAWgBRIf1yoyLjHhGr1+UFaMt/UPhoZ8DAFBgMrZXADQQAeRBXv6WCTOp0G\n" + "3wgd8bbEGrrILfpi+qH7aj/MywgkPIlppDYRQ3jL6ASd+So/408dlE0DV9DXKBi0\n" + "725XUUYO\n" + "-----END CERTIFICATE-----\n", + /* C (signed by A) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhRvbZv3SRTjDOiAbyFWHH4y0yMZkjAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBBMCAXDTI0MDExMTA2MTg1MVoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEMwKjAFBgMrZXADIQDxm6Ubhsa0gSa1vBCIO5e+qZEH\n" + "8Oocz+buNHfIJbh5NaNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFEh/XKjIuMeEavX5QVoy39Q+GhnwMB8GA1UdIwQYMBaAFFti\n" + "A6REax3dnvj4Jq5fiG3MuDSXMAUGAytlcANBAPl+SyiOfXJnjSWx8hFMhJ7w92mn\n" + "tkGifCFHBpUhYcBIMeMtLw0RBLXqaaN0EKlTFimiEkLClsU7DKYrpEEJegs=\n" + "-----END CERTIFICATE-----\n", + /* C (signed by B) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBSDCB+6ADAgECAhQU1OJWRVOLrGrgJiLwexd1/MwKkTAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBCMCAXDTI0MDExMTA2MjAzMFoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEMwKjAFBgMrZXADIQDxm6Ubhsa0gSa1vBCIO5e+qZEH\n" + "8Oocz+buNHfIJbh5NaNjMGEwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFEh/XKjIuMeEavX5QVoy39Q+GhnwMB8GA1UdIwQYMBaAFJFA\n" + "s2rg6j8w9AKItRnOOOjG2FG6MAUGAytlcANBALXeyuj8vj6Q8j4l17VzZwmJl0gN\n" + "bCGoKMl0J/0NiN/fQRIsdbwQDh0RUN/RN3I6DTtB20ER6f3VdnzAh8nXkQ4=\n" + "-----END CERTIFICATE-----\n", + NULL +}; + +static const char *cross_signed_ca[] = { + /* A (self-signed) */ + "-----BEGIN CERTIFICATE-----\n" + "MIIBJzCB2qADAgECAhQs1Ur+gzPs1ISxs3Tbs700q0CZcjAFBgMrZXAwETEPMA0G\n" + "A1UEAxMGUm9vdCBBMCAXDTI0MDExMTA2MTYwMFoYDzk5OTkxMjMxMjM1OTU5WjAR\n" + "MQ8wDQYDVQQDEwZSb290IEEwKjAFBgMrZXADIQA0vDYyg3tgotSETL1Wq2hBs32p\n" + "WbnINkmOSNmOiZlGHKNCMEAwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMC\n" + "AgQwHQYDVR0OBBYEFFtiA6REax3dnvj4Jq5fiG3MuDSXMAUGAytlcANBAHrVv7E9\n" + "5scuOVCH9gNRRm8Z9SUoLakRHAPnySdg6z/kI3vOgA/OM7reArpnW8l1H2FapgpL\n" + "bDeZ2XJH+BdVFwg=\n" + "-----END CERTIFICATE-----\n", + NULL +}; + #if defined __clang__ || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wunused-variable" #endif @@ -4440,10 +4563,12 @@ static struct 0, NULL, 1620052390, 1}, { "rsa-sha1 not in trusted - not ok", rsa_sha1_not_in_trusted, rsa_sha1_not_in_trusted_ca, GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_MEDIUM), GNUTLS_CERT_INSECURE_ALGORITHM | GNUTLS_CERT_INVALID, NULL, 1620118136, 1}, + { "cross signed - ok", cross_signed, cross_signed_ca, 0, 0, 0, + 1704955300 }, { NULL, NULL, NULL, 0, 0} }; #if defined __clang__ || __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5) # pragma GCC diagnostic pop