Tagged Questions
5
votes
5answers
154 views
A standard way to manually add a digital signature to a pdf file?
I've created a few certificates to use myself, but I find myself stumped when it comes to creating a certificate which contains a digital signature. First, how would I go about creating a standard ...
1
vote
1answer
78 views
x509: must the signature algorithm and public key algorithm match?
I'm having trouble getting Firefox to send an encrypted message using a certificate, and I've found that the only difference between this one and others that work fine are that this one has a DSA ...
1
vote
1answer
80 views
Can I use any ssl certificate to sign and encrypt AS2 message?
I'm absolutely new to this topic of ssl certificates, so please be patient with me.
My task is to install an AS2 communication with some business partner. Therefore we need message signing and ...
0
votes
1answer
103 views
How to test for OCSP
I have to test OCSP feature on a SSL server. Since it is a pretty standard feature now, I was looking around for tips on test plans / setting up OCSP responder etc. I have not found anything so far. ...
3
votes
2answers
90 views
Why are SSL certificates valid only from a certain date?
Each SSL certificate is valid starting from a specific date and up to the expiration date.
What's the point in that "valid from" date? Why do we want a certificate to only be valid after a specific ...
3
votes
1answer
259 views
Enhanced Key Usage vs. Extended Key Usage
I've seen both the terms Enhanced Key Usage and Extended Key Usage, and both were abbreviated as EKU. Do both refer to the same extension or property?
41
votes
10answers
2k views
Why do we not trust an SSL certificate that expired recently?
Every SSL certificate has an expiration date. Now suppose some site's certificate expired an hour ago or a day ago. All the software by default will either just refuse to connect to the site or issue ...
4
votes
1answer
150 views
Why do X.509 certificates have “Key Usage” attribute?
I can find their values and all details in the RFC, but I cannot find why it was decided to have this attribute in certificates, instead of leaving them to be multipurposes.
Is there a reasoning ...
4
votes
1answer
118 views
Which properties of a X.509 certificate should be critical and which not?
RFC5280's section 4.2 states
Each extension in a
certificate is designated as either critical or non-critical. A
certificate-using system MUST reject the certificate if it encounters
...
1
vote
1answer
113 views
How to troubleshoot why Thunderbird rejects a PKCS#12 certificate with “Could not verify this certificate for unknown reasons”?
After playing around a bit with openssl, I created a PKCS12 certificate which imports flawlessly in Firefox while Thunderbird "Could not verify this certificate for unknown reasons". Talk about a ...
11
votes
4answers
2k views
What is certificate pinning?
I'm superficially familiar with SSL and what certs do. Recently I saw some discussion on cert pinning but there wasn't a definition. A DDG search didn't turn up anything useful. What is certificate ...
3
votes
4answers
470 views
Is it possible to create a self signed certificate authority?
Would it be possible to create a legitimate certificate with the CA bit set? I dont have a usecase associated with this, I'm merely curious.
To explain my question : Suppose I sign a public ...
0
votes
1answer
109 views
Behavior when validating an expired certificate chain
I have the following situation:
A server certificate (CServ) is signed by self-signed certificate (C0)
A client certificate (CCli) is signed by CServ
Client's trust-store contains C0, so the client ...
2
votes
1answer
108 views
What damage could be done if a malicious certificate had an identical “Subject Key Identifier”?
I'm looking at the the Subject Key Identifier attribute of a CA certificate and am trying to understand the role it plays in validation and infer how validating client software could get it wrong.
...
2
votes
1answer
54 views
Is it a good idea to generate certificate-specific CRLs? What is this technique called?
Suppose I create 3 certificates with the following CRLs
Cert1 http://crl.server.com/batch1/root1.crl
Cert2 http://crl.server.com/batch2/root2.crl
Cert3 ...
2
votes
1answer
184 views
What should a CRL file name look like when “new” and “delta” CRLs are generated?
I suspect my Windows 20012 Certificate Server CRL revocation configuration is incorrect every time I generate a new CRL or a new Delta, only a maximum of 3 files are generated.
When I created the ...
2
votes
1answer
157 views
What Enhanced Key Usages are required for PKI infrastructure tasks? (OIDs for OSPF and CRL signing, etc)
I'm building a constrained PKI that specifies EKUs for the the entire hierarchy and want to document the OIDs required for PKI tree maintenance tasks.
I understand that clients may not validate the ...
4
votes
2answers
207 views
Extensions for SSL server certificate
I have some question about the X.509 v3 extensions. What extensions should appear in a proper certificate for a SSL server ?
3
votes
2answers
232 views
Is an AIA or CRL useful / required at the Root CA if that Root is used to cross certify another PKI?
Suppose I have several independent PKIs that are used
Two internal PKIs: One with SHA1 support the other with Suite B algorithms.
A partner who I trust and have a policy map with.
Since both my ...
2
votes
1answer
236 views
What OID Issuance Policies are appropriate for SmartCard and Browser Certificates?
I'm investigating issuance policies for SMIME and Browser certificates with different levels of assurance.
For the purposes of S/MIME and Browser certificates, should I even use an assurance policy? ...
24
votes
3answers
810 views
A Different Approach to PKI
After yet another failure of the public key infrastructure, I was thinking about how broken the whole thing is. This business of undeniably associating an identity with a public key, and all the work ...
1
vote
2answers
192 views
Difference between Encryption and Verification certificate
What is the difference between the Encryption certificate and Verification certificate in Outlook? When exchanging certs, it just requires a digitally-signed message to be sent. It seems as though ...
1
vote
1answer
131 views
How do I verify, parse and process the results of the HTML5 keygen tag?
I'm investigating the HTML5 attribute Keygen and discovered that it sends this data on a Form POST to the server. Here is an example POST:
...
1
vote
2answers
192 views
Self-signed certificates usage for code signing purposes
if a self-signed certificate is trusted by the client's certificate store, then it should be fine to be used, since the client trusts the issuer of the certificate as it does any other trusted CA ...
-1
votes
4answers
232 views
Does a renewed certificate open old messages?
I have a digital certificate that I use to exchange messages with peers, my certificate expiration date is due next year, suppose I renew this certificate before it expires, will I be able to open the ...
2
votes
1answer
76 views
how does OpenSSL create X.509 certs from SPKACs?
The SPKAC ASN.1 description:
PublicKeyAndChallenge ::= SEQUENCE {
spki SubjectPublicKeyInfo,
challenge IA5STRING
}
SignedPublicKeyAndChallenge ::= SEQUENCE {
publicKeyAndChallenge ...
3
votes
2answers
161 views
What did the certificate authority do with my CSR?
I needed to reach a web service which is not mine.
The IT department of that web service has asked me to send them a CSR (certificate signing request).
Then, he will send me back a signed certificate ...
4
votes
3answers
266 views
What issues arise from sharing a SSL certificate's private key?
Scenario: I am hosting a website for a my client, who we'll call S. S owns the domain s.com and I own the servers that actually host the website. S now wants to enable SSL on their website.
I have ...
3
votes
3answers
441 views
How to distribute client certificates without exposing private key?
I'm desgining a B2B web service based on WCF. As the number of clients is relatively small and security is a priority, i have chosen to go with X509 client certificates for client authentication.
I'm ...
2
votes
2answers
144 views
distribution mechanisms for CRLs
From the X.509 RFC:
DistributionPoint ::= SEQUENCE {
distributionPoint [0] DistributionPointName OPTIONAL,
reasons [1] ReasonFlags OPTIONAL,
cRLIssuer ...
11
votes
4answers
401 views
What alternatives are there to the existing Certificate Authority system for SSL?
Whilst the current CA system works very well for a lot of people, it does put a lot of power into individual CAs' hands, and makes a CA hack potentially devastating for customers and business. What ...
1
vote
2answers
94 views
Certificate Security in intranet Environment?
We have this topology in our company :
A new rule says that each document being sent by outlook should be encrypted.
we decided using PGP.
We already have a certificate ( self signed).
the ...
5
votes
1answer
179 views
Which attributes of a X509v3 certificate are never really used?
Are there any extensions/extended key usage attributes of a X.509Certificate that are rarely or never used in practice?
Either due to never being part of an issued certificate or because they are ...
8
votes
2answers
601 views
Are there really functioning quantum computers?
I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
3
votes
1answer
151 views
What are the Netscape Cert Type attributes? Why/when are they needed?
What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions?
Example:
There is the Client/Server Extended Key Usage (X.509) but there is ...
2
votes
2answers
257 views
Revoked certificate validation using past times
I'm working on XAdES implementation for Java, as such I require cryptographic implementation to be able to verify certificates in the past.
Unfortunately I have problems verifying revoked ...
5
votes
2answers
142 views
ASN.1: ENUMERATED vs INTEGER
From the X.509 specs:
CRLReason ::= ENUMERATED {
unspecified (0),
keyCompromise (1),
cACompromise (2),
affiliationChanged (3),
...
2
votes
1answer
79 views
Which .CER file format is more secure for purposes of an AIA record?
What file format is most appropriate or secure for the AIA record in a PKI certificate?
The options I'm aware of are:
DER encoded binary X.509 (.cer)
Base-64 encoded X.509 (.cer)
I also have the ...
1
vote
1answer
75 views
What keys are involved in an X.509 certificate?
I'm trying to examine some instances where an X.509 certificate uses public and private keys for a paper I'm going to write. However, the only thing I have explicitly seen so far is in one of the ...
3
votes
2answers
415 views
x.509 CRLs: next update?
An X.509 certificate revocation list contains a field specifying when the next such list is expected to be issued. I'm trying to figure out the importance of this field...I know that sometimes ...
5
votes
3answers
237 views
Digital Signature and Verification?
AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it.
So public key is used to decrypt ...
4
votes
3answers
557 views
How is an X509 certificate signer verified?
Lets say I create a self-signed certificate A and use it to issue certificate B. I put certificate A in my trusted root authorities so that all certificates signed by it are accepted. My question is,
...
173
votes
3answers
45k views
How does SSL work?
How does SSL work? I just realised we don't actually have a definitive answer here, and it's something worth covering.
I'd like to see details in terms of:
A high level description of the protocol.
...
6
votes
3answers
173 views
What risks would exist in transmitting an encrypted PKCS12 via Https
I have a scenario in which I would like to automate the deployment of client certificates generated by an issuer I control. The approach I am considering is given below, and I would appreciate ...
2
votes
2answers
72 views
Using a verified certificate to sign others
OK my Google Fu has failed me as I'm not exactly sure what I'm searching for. This relates to PKI ad certificates generally but websites more specifically.
Could you get a verified certificate from ...
4
votes
1answer
56 views
Standards for CA cert revocation and time-constrained cryptographic algorithm parameters
I'm working on software that will be in use for foreseeable future (15 years+) that will need to validate XAdES-A signatures (long term archival, similar to PAdES-A, but for XML). That means, it will ...
5
votes
1answer
70 views
Is it possible to have multiple key lengths in PKI?
Is it possible to have multiple key lengths in a PKI? For example, use a 1024-bit key for the issued certificate, a 2048-bit key for the intermediate certificate, and 4096-bit key for the root ...
3
votes
1answer
61 views
CMC (RFC 5272) compatible CA server
I need a CA server or any tool that supports Certificate Management over CMS (CMC) format, described in RFC 5272 (RFC 2797). I need a possibility to generate different Full PKI requests and responses ...
3
votes
1answer
55 views
Within a CSR, is there a field to have the MS PKI server change the default cert filename
I'm not intimately familiar with MS PKI, but it was a question that came up in a discussion for an issue a coworker is having. When you input the request fields manually on a PKI server, the cert ...
4
votes
5answers
433 views
Is Spoofing a CA signed certificate possible?
I had never thought about this situation before, I may be completely wrong but I am going to have to clarify it anyway.
When a communication starts with a server, during the client handshake, the ...
