nav b wrote:
In the ITU-T Recommendation H.235 I found the ASN.1 expression
SIGNED { ToBeSigned } ::= SEQUENCE {
toBeSigned ToBeSigned,
algorithmOID OBJECT IDENTIFIER,
paramS Params, -- any "runtime" parameters
signature BIT STRING -- could be an RSA or an ASN.1 coded ECGDSASignature
} ( CONSTRAINED BY { -- Verify or Sign Certificate -- } )
this is my understanding of above structure N::= SIGNED { XYZ }
is equalent of
N::=SEQUENCE {
toBeSigned XYZ,
algorithmOID OBJECT IDENTIFIER,
paramS Params, -- any "runtime" parameters
signature BIT STRING -- could be an RSA or an ASN.1 coded ECGDSASignature
} ( CONSTRAINED BY { -- Verify or Sign Certificate -- } )
is my understanding right?
Yes, for the purposes of encoding. However, it probably better be compiled into something that facilitates computing a signature of XYZ. Some special structure or something. Depends on the compiler though.
& does the CONSTRAINED BY which is a user-defined constraint, can it be ignored here?
Only if you want do deliberately break the protocol this structure is defined for. An example would be if you want to display the contents of the bad certificate without doing any computations to Verify or Sign the certificate.
ENCRYPTED { ToBeEncrypted } ::= SEQUENCE { algorithmOID OBJECT IDENTIFIER, paramS Params, -- any "runtime" parameters encryptedData OCTET STRING } ( CONSTRAINED BY { -- Encrypt or Decrypt -- ToBeEncrypted } )
HASHED { ToBeHashed } ::= SEQUENCE { algorithmOID OBJECT IDENTIFIER, paramS Params, -- any "runtime" parameters hash BIT STRING } ( CONSTRAINED BY { -- Hash -- ToBeHashed } )
the ENCRYPTED & HASHED structures, also have same issues as SIGNED
They are the same. These syntaxes are defined in X.683 (ISO 8824-4), Parametrization of ASN.1 specifications.
Thanks a lot
Naveen Kumar B K Encore Software Limited _______________________________________________ ASN1 mailing list [EMAIL PROTECTED] http://lists.asn1.org/mailman/listinfo/asn1
-- Lev Walkin [EMAIL PROTECTED] _______________________________________________ ASN1 mailing list [EMAIL PROTECTED] http://lists.asn1.org/mailman/listinfo/asn1
