trust: Handle incorrectly encoded CKA_SERIAL_NUMBER lookups

Handle lookups for trust objects (by NSS) which expect CKA_SERIAL_NUMBER
attributes without appropriate DER encoding.

In addition allow creation of NSS trust objects as PKCS#11 session
objects, so that we can test this behavior.

3 files changed, 114 insertions, 1 deletions

diff --git a/trust/builder.c b/trust/builder.c
index 65aa5dd..0a020cf 100644
--- a/trust/builder.c
+++ b/trust/builder.c
@@ -728,7 +728,7 @@ build_for_schema (p11_builder *builder,
         if (attrs != NULL)
                 attrs_filter_if_unchanged (attrs, merge);
 
-        if (creating) {
+        if (creating && (builder->flags & P11_BUILDER_FLAG_TOKEN)) {
                 if (schema->build_flags & GENERATED_CLASS) {
                         p11_message ("objects of this type cannot be created");
                         return CKR_TEMPLATE_INCONSISTENT;
diff --git a/trust/module.c b/trust/module.c
index dcf4e8f..3ef4034 100644
--- a/trust/module.c
+++ b/trust/module.c
@@ -45,6 +45,7 @@
 #include "module.h"
 #include "parser.h"
 #include "pkcs11.h"
+#include "pkcs11x.h"
 #include "session.h"
 #include "token.h"
 
@@ -1047,6 +1048,49 @@ sys_C_SetAttributeValue (CK_SESSION_HANDLE handle,
         return rv;
 }
 
+static CK_ATTRIBUTE *
+work_around_broken_nss_serial_number_lookups (CK_ATTRIBUTE *attrs)
+{
+        /*
+         * WORKAROUND: NSS calls us asking for CKA_SERIAL_NUMBER items that are
+         * not DER encoded. It shouldn't be doing this. We never return any certificate
+         * serial numbers that are not DER encoded.
+         *
+         * So work around the issue here while the NSS guys fix this issue.
+         * This code should be removed in future versions.
+         */
+
+        CK_OBJECT_CLASS klass;
+        CK_ATTRIBUTE *serial;
+        unsigned char *der;
+        size_t der_len;
+        int len_len;
+
+        if (!p11_attrs_find_ulong (attrs, CKA_CLASS, &klass) ||
+            klass != CKO_NSS_TRUST)
+                return attrs;
+
+        serial = p11_attrs_find_valid (attrs, CKA_SERIAL_NUMBER);
+        if (!serial || p11_asn1_tlv_length (serial->pValue, serial->ulValueLen) >= 0)
+                return attrs;
+
+        p11_debug ("working around serial number lookup that's not DER encoded");
+
+        /* Assumption that 32 bytes is more than enough to store a ulong */
+        der_len = 1 + 32 + serial->ulValueLen;
+        der = malloc (der_len);
+        return_val_if_fail (der != NULL, NULL);
+
+        der[0] = ASN1_TAG_INTEGER | ASN1_CLASS_UNIVERSAL;
+        len_len = der_len - 1;
+        asn1_length_der (serial->ulValueLen, der + 1, &len_len);
+        assert (len_len < der_len - serial->ulValueLen);
+        memcpy (der + 1 + len_len, serial->pValue, serial->ulValueLen);
+        der_len = 1 + len_len + serial->ulValueLen;
+
+        return p11_attrs_take (attrs, CKA_SERIAL_NUMBER, der, der_len);
+}
+
 static CK_RV
 sys_C_FindObjectsInit (CK_SESSION_HANDLE handle,
                        CK_ATTRIBUTE_PTR template,
@@ -1095,6 +1139,9 @@ sys_C_FindObjectsInit (CK_SESSION_HANDLE handle,
                                 find->match = p11_attrs_buildn (NULL, template, count);
                                 warn_if_fail (find->match != NULL);
 
+                                find->match = work_around_broken_nss_serial_number_lookups (find->match);
+                                warn_if_fail (find->match != NULL);
+
                                 /* Build a session snapshot of all objects */
                                 find->iterator = 0;
                                 find->snapshot = p11_index_snapshot (indices[0], indices[1], template, count);
diff --git a/trust/tests/test-module.c b/trust/tests/test-module.c
index 4606a31..de0a3b1 100644
--- a/trust/tests/test-module.c
+++ b/trust/tests/test-module.c
@@ -788,6 +788,71 @@ test_session_remove (CuTest *cu)
         teardown (cu);
 }
 
+static void
+test_find_serial_der_decoded (CuTest *cu)
+{
+        CK_OBJECT_CLASS nss_trust = CKO_NSS_TRUST;
+
+        CK_ATTRIBUTE object[] = {
+                { CKA_CLASS, &nss_trust, sizeof (nss_trust) },
+                { CKA_SERIAL_NUMBER, "\x02\x03\x01\x02\x03", 5 },
+                { CKA_INVALID }
+        };
+
+        CK_ATTRIBUTE match_decoded[] = {
+                { CKA_CLASS, &nss_trust, sizeof (nss_trust) },
+                { CKA_SERIAL_NUMBER, "\x01\x02\x03", 3 },
+                { CKA_INVALID }
+        };
+
+        CK_SESSION_HANDLE session;
+        CK_OBJECT_HANDLE handle;
+        CK_OBJECT_HANDLE check;
+        CK_ULONG count;
+        CK_RV rv;
+
+        /*
+         * WORKAROUND: NSS calls us asking for CKA_SERIAL_NUMBER items that are
+         * not DER encoded. It shouldn't be doing this. We never return any certificate
+         * serial numbers that are not DER encoded.
+         *
+         * So work around the issue here while the NSS guys fix this issue.
+         * This code should be removed in future versions.
+         *
+         * See work_around_broken_nss_serial_number_lookups().
+         */
+
+        setup (cu);
+
+        rv = test.module->C_OpenSession (test.slots[0], CKF_SERIAL_SESSION, NULL, NULL, &session);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+
+        rv = test.module->C_CreateObject (session, object, 2, &handle);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+
+        /* Do a standard find for the same object */
+        rv = test.module->C_FindObjectsInit (session, object, 2);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+        rv = test.module->C_FindObjects (session, &check, 1, &count);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+        CuAssertIntEquals (cu, 1, count);
+        CuAssertIntEquals (cu, handle, check);
+        rv = test.module->C_FindObjectsFinal (session);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+
+        /* Do a find for the serial number decoded */
+        rv = test.module->C_FindObjectsInit (session, match_decoded, 2);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+        rv = test.module->C_FindObjects (session, &check, 1, &count);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+        CuAssertIntEquals (cu, 1, count);
+        CuAssertIntEquals (cu, handle, check);
+        rv = test.module->C_FindObjectsFinal (session);
+        CuAssertIntEquals (cu, CKR_OK, rv);
+
+        teardown (cu);
+}
+
 int
 main (void)
 {
@@ -814,6 +879,7 @@ main (void)
         SUITE_ADD_TEST (suite, test_session_copy);
         SUITE_ADD_TEST (suite, test_session_remove);
         SUITE_ADD_TEST (suite, test_session_setattr);
+        SUITE_ADD_TEST (suite, test_find_serial_der_decoded);
 
         CuSuiteRun (suite);
         CuSuiteSummary (suite, output);