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Questions tagged [cms]

CMS is an acronym for the Cryptographic Message Syntax, as defined in RFC5652

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2answers
275 views

What exactly is the contents of the LDAP userSMIMECertificate attribute?

I'm trying to setup an LDAP with user certificates. I have already learned that certificates can be stored in either the userCertificate attribute in DER format, or ...
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1answer
237 views

PKCS#7 non-detached Signature - Help understand the message structure

I am pretty new to ASN.1 format. I have a PKCS#7 signature which after doing an ASNdump looks like the one below. Can someone help me understand what each element below signifies? I could only ...
3
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1answer
84 views

How does RFC 5652 authenticated data confirm origin and data integrity?

My reading of RFC 5652 Authenticated-Data does not give receiver confidence in originator of message, and therefore can not provide data integrity certainty. Originator process is: ...
6
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1answer
26k views

Is PKCS7 a signature format or a certificate format?

I always though PKCS7 was a signature format. However, on the net I find several references to PKCS7 being a certificate format - for example, this talks about PKCS7 certificate: Extract raw ...
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1answer
176 views

What does CMS standard mean by “initial input to the message digest”

I'm really grinding my teeth against digest calculation explanation in the CMS standard. Let's consider the case when the signedAttrs are present. The first ...
4
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0answers
205 views

Are there any test vectors for the CMS content type AuthEnvelopedData (for AES-GCM)?

I am looking for CMS AuthEnvelopedData test vectors for AES-GCM mode. I haven’t seen any ready-to-use test vectors for it. There are test vectors for AES-GCM mode but not for its CMS support. I even ...
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0answers
1k views

How do I create a PKCS#7 or CMS SignedData in python? [closed]

There doesn't appear to be PKCS#7 or CMS support in pyCrypto. I'd appreciate a recommendation on a Python library wth CMS / PKCS#7 support. Ideally, there will be a call that will create return ...
3
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1answer
517 views

Size of encrypted AES CEK in CMS block

When I run openssl cms -encrypt -aes256 -in sample.der -out wrapped.der -outform DER -recip ecc.crt -keyopt ecdh_kdf_md:sha512 the part of the CMS output which ...
1
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1answer
898 views

PKCS#7 signed data structure in signed PDF document

Is it mandatory to include PKCS#7 data (OID 1.2.840.113549.1.7.1) octet string into the sequence of PKCS#7 signed data? I mean if you want to sign PDF, you are basically adding PKCS#7 container ...
1
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1answer
2k views

extract ciphertext from encrypted SMIME file

the main question of this message is how to get the true ciphertext from S/MIME file? I created RSA keys and encrypted a message with S/MIME as follow : ...
1
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1answer
1k views

Using C_Sign to create a PKCS7 signature

I am using the PKCS#11 function C_Sign to sign some data. The output I get is just a signature. How do I get it in PKCS#7 format - i.e. ASN1 with signature and certificate (for detached) or ASN1 with ...
2
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0answers
211 views

Where is the OID and ASN.1 specified for AES_CMAC?

I have a requirement to implement AES_CMAC as the authentication algorithm in a CMS library. I just can't seem to find the OID and the ASN.1 definition for it. I expected to see the OID under {joint-...