Issue in parameterized types

[Anonymous]

Hello,

I'm using asn1c to compile the PKCS#15 module where there are many parameterized types, e.g.:

PKCS15Object {ClassAttributes, SubClassAttributes, TypeAttributes}
    ::= SEQUENCE {
    commonObjectAttributes CommonObjectAttributes,
    classAttributes ClassAttributes,
    subClassAttributes EXPLICIT SubClassAttributes OPTIONAL,
    typeAttributes EXPLICIT TypeAttributes
}

PrivateKeyType ::= CHOICE {
-    privateRSAKey PrivateKeyObject {PrivateRSAKeyAttributes},
    privateRSAKey PKCS15Object {CommonKeyAttributes, CommonPrivateKeyAttributes, PrivateRSAKeyAttributes},
-    privateECKey PrivateKeyObject {PrivateECKeyAttributes}
    privateECKey   PKCS15Object {CommonKeyAttributes, CommonPrivateKeyAttributes, PrivateECKeyAttributes},
-    privateDHKey PrivateKeyObject {PrivateDHKeyAttributes},
-    privateDSAKey PrivateKeyObject {PrivateDSAKeyAttributes},
-    privateKEAKey PrivateKeyObject {PrivateKEAKeyAttributes},
    … - For future extensions
}

-PrivateKeyObject {KeyAttributes} ::= PKCS15Object {
-    CommonKeyAttributes, CommonPrivateKeyAttributes, KeyAttributes}

PrivateRSAKeyAttributes ::= SEQUENCE {
-    value ObjectValue {RSAPrivateKeyObject},
    value ObjectValue,
    modulusLength INTEGER, - modulus length in bits, e.g. 1024
-    keyInfo  KeyInfo {NULL, PublicKeyOperations} OPTIONAL,
    keyInfo  KeyInfo OPTIONAL,
    … - For future extensions
}

PrivateECKeyAttributes ::= SEQUENCE {
-    value  ObjectValue {ECPrivateKey},
    value  ObjectValue,
-    keyInfo KeyInfo {Parameters, PublicKeyOperations} OPTIONAL,
    keyInfo KeyInfo OPTIONAL,
    … - For future extensions
}

As you can see from the code above, I've done some modifications in order to compile it by asn1c.

The problem is that it generates only a C struct (specialization according of asn1c source code) with the PrivateRSAKeyAttributes for both privateRSAKey and privateECKey regardless of their last parameter (PrivateRSAKeyAttributes vs PrivateECKeyAttributes).

I've done some testings and only if I modify the first parameter of the type instantiation it creates a new specialization.

Reading the source, I think the problem may be located either in compare_specializations() at asn1fix_param.c, where two specializations are compared, or in asn1f_parameterization_fork() at asn1fix_param.c where a new specialization is created.

How hard is it to fix?

Regards.

[Lev Walkin]

It's nasty and hard.

[Anonymous]

A solution is redefine it as:

PrivateKeyType ::= CHOICE {
-    privateRSAKey PrivateKeyObject {PrivateRSAKeyAttributes},
    privateRSAKey SEQUENCE {
                      commonObjectAttributes CommonObjectAttributes,
                      classAttributes     CommonKeyAttributes,
                      subClassAttributes EXPLICIT CommonPrivateKeyAttributes OPTIONAL,
                      typeAttributes      EXPLICIT PrivateRSAKeyAttributes
                  },
-    privateECKey PrivateKeyObject {PrivateECKeyAttributes}
    privateECKey    SEQUENCE {
                           commonObjectAttributes CommonObjectAttributes,
                           classAttributes     CommonKeyAttributes,
                           subClassAttributes EXPLICIT CommonPrivateKeyAttributes OPTIONAL,
                           typeAttributes      EXPLICIT PrivateECKeyAttributes
                       },
-    privateDHKey PrivateKeyObject {PrivateDHKeyAttributes},
-    privateDSAKey PrivateKeyObject {PrivateDSAKeyAttributes},
-    privateKEAKey PrivateKeyObject {PrivateKEAKeyAttributes},
    … - For future extensions
}

Thus removing all parameterized types.

Thanks.