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1
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1answer
30 views

How do I get the subject public key from a PKCS7 message?

Quoting RFC4562, Cryptographic Message Syntax (CMS), section 5.6. Signature Verification Process: The recipient MAY obtain the correct public key for the signer by any means, but the preferred ...
2
votes
1answer
27 views

Why is the digest algorithm specified in two places in CMS / PKCS7?

In RFC5652, Cryptographic Message Syntax (CMS), section 5.3. SignerInfo Type, there's a digestAlgorithm field that has values like id-sha256, id-sha1, etc. In that same RFC, section 5.1. SignedData ...
0
votes
0answers
18 views

Enhanced Security Services / CAdES for PKCS7 - multiple signers for SignerInfo's?

In RFC5652, Cryptographic Message Syntax (CMS), section 5.3. SignerInfo Type, there's a sid field that maps to this: SignerIdentifier ::= CHOICE { issuerAndSerialNumber IssuerAndSerialNumber, ...
0
votes
1answer
20 views

extendedCertificate's in PKCS7 / CMS

In PKCS7 / CMS, for the signed-data content type, there's a CertifcateChoices field in the certicates field in SignedData that is a SET of CertificateChoices. CertificateChoices is defined thusly: ...
10
votes
2answers
371 views

Are there any meta-formats for crypto?

Are there are any (properly specified) meta-formats / schema formats for describing cryptographic message structures? I'm looking for a way to describe the format (where some channels might want ...
2
votes
0answers
40 views

CMS/PKCS#7: specifying signatureAlgorithm with digest?

I'm confused about algorithm selection for Cryptographic Message Syntax (a.k.a. CMS, PKCS#7) signed objects (RFC5652 Section 5.1). The SignerInfo structure (RFC5652 Section 5.3) has two separate ...
1
vote
0answers
39 views

Downloadable Autonomous System contact information

When under (a security) attack, it might be useful for the victim to first identify the source IP, then potentially contact the offending ISP. There seem to be plenty of tools for the part where an IP ...
1
vote
3answers
598 views

What part of the CSR is hashed in order to create its signature?

I'd like to change the CSR before it is transferred to the CA without going through the CSR creation process again. To do that I need to know how to calculate the signature of the CSR after I modified ...
1
vote
0answers
39 views

is this optional keyword redundant? [closed]

KDC-REQ ::= SEQUENCE { -- NOTE: first tag is [1], not [0] pvno [1] INTEGER (5) , msg-type [2] INTEGER (10 -- AS -- | 12 -- TGS --), padata [3] SEQUENCE OF PA-DATA ...
2
votes
1answer
718 views

question about implicitly tags in ASN.1

From the X.509 RFC, in the "Implicitly Tagged Module" section: CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] ...
6
votes
2answers
931 views

ASN.1: ENUMERATED vs INTEGER

From the X.509 specs: CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), ...
5
votes
1answer
2k views

Why does openssl writes EC parameters when generating private key?

When I'm generating a private key with openssl, it writes the curve's parameters, and the actual private key: ❯ openssl ecparam -name secp256k1 -genkey -----BEGIN EC PARAMETERS----- BgUrgQQACg== ...
3
votes
1answer
1k views

How to verify the signature in an iOS Passbook pass?

The Passbook application in the new iOS6 keeps track of movie tickets, coupons, and other 'passes' for you, and the passes themselves are loaded onto the user's device via file packages with the ...
6
votes
3answers
493 views

How do I test and secure ASN.1 Parsers?

As far as I can tell, .NET doesn't have an ASN.1 parser for reading or writing data built in the framework. This means that any code that creates or verifies ASN.1 data is using a 3rd party library ...