> -----Original Message----- > From: Henrick Hellström [mailto:henr...@streamsec.se] > Sent: Sunday, September 25, 2016 4:42 PM > To: Jim Schaad <i...@augustcellars.com>; 'David Benjamin' > <david...@google.com>; tls@ietf.org > Subject: Re: [TLS] BoringSSL's TLS test suite > > On 2016-09-26 01:29, Jim Schaad wrote: > > The ASN.1 module in RFC 5280 does not say anything about if the field > > is optional for any specific algorithm. The ASN.1 for algorithm > > identifier is > > > > AlgorithmIdentifier ::= SEQUENCE { > > algorithm OBJECT IDENTIFIER, > > parameters ANY DEFINED BY algorithm OPTIONAL > > > > This very explicitly says that the value (and hence presence) of the > > parameters fields is strictly defined by the algorithm identifier. > > The algorithm identifiers for RSA with the SHA2 algorithms explicitly > > say they are required. > > > > > > RFC 5912 shows that this is required with the way it defines the same > > information > > > > sa-sha256WithRSAEncryption SIGNATURE-ALGORITHM ::= { > > IDENTIFIER sha256WithRSAEncryption > > PARAMS TYPE NULL ARE required > > HASHES { mda-sha256 } > > PUBLIC-KEYS { pk-rsa } > > SMIME-CAPS { IDENTIFIED BY sha256WithRSAEncryption } > > } > > > > You can see that the parameters are required and not optional. > > Thanks, you are absolutely correct about this, and this crucial for getting > PKCS > #1 v1.5 signatures right (since the algorithm identifier encoding is part of > the > data to be signed), but at the same time, NULL should be absent from the RSA > public key: > > pk-rsa PUBLIC-KEY ::= { > IDENTIFIER rsaEncryption > KEY RSAPublicKey > PARAMS TYPE NULL ARE absent > -- Private key format not in this module -- > CERT-KEY-USAGE {digitalSignature, nonRepudiation, > keyEncipherment, dataEncipherment, keyCertSign, cRLSign} > } > > and this is definitely not common practice.
No, it appears that I messed this up. (: It should be required and not absent. The text in RFC3279 says The parameters field MUST have ASN.1 type NULL for this algorithm identifier. Unhappiness. _______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
