Add various PKCS7 getters and setters

[WillChilds-Klein]

Issues:

Resolves CryptoAlg-2482

Description of changes:

Following up PR 1726, this PR adds various getter/setter functions needed to support ruby and provides test coverage for them. We also add test coverage for the various ASN.1 functions and PKCS7_dup added in PR 1726.

This commit borrows a sample PKCS7 SignedData from https://lapo.it/asn1js/ that, unlike other test fixtures, contains SignerInfos. That sample object has been hand-edited to reduce its size (~10KiB of an inner EncapsulatedContentInfo object were consumed by filler). You can see a parsed illustration of the new fixture here.

The next PR in this series will implement PKCS7's BIO-based data initialization and finalization functions.

Call-outs:

• none

Testing:

• CI

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 79.53964% with 80 lines in your changes missing coverage. Please review.

Project coverage is 78.45%. Comparing base (0f5d9c9) to head (af6e069).

Files with missing lines	Patch %	Lines
crypto/pkcs7/pkcs7.c	75.80%	68 Missing ⚠️
crypto/pkcs7/pkcs7_x509.c	74.46%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1780      +/-   ##
==========================================
+ Coverage   78.40%   78.45%   +0.04%     
==========================================
  Files         584      584              
  Lines       97777    98170     +393     
  Branches    14020    14087      +67     
==========================================
+ Hits        76666    77016     +350     
- Misses      20488    20530      +42     
- Partials      623      624       +1     

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[samuel40791765]

1. A lot of the PKCS7 setters/getters seem to only apply to applicable or relevant types. Should we add which specific types are relevant in the function documentation?
2. Nit: There are some remnants of OpenSSL's comment style in crypto/pkcs7/pkcs7.c that we should switch up. It'd also help to run clang-format on the file since the brackets and spacing are a bit inconsistent.

[WillChilds-Klein]

@samuel40791765 --

1. A lot of the PKCS7 setters/getters seem to only apply to applicable or relevant types. Should we add which specific types are relevant in the function documentation?

sure, i can do that.

2. Nit: There are some remnants of OpenSSL's comment style in crypto/pkcs7/pkcs7.c that we should switch up. It'd also help to run clang-format on the file since the brackets and spacing are a bit inconsistent.

that's reasonable, although I'd like to do it in a separate PR that only applies clang-format.

[samuel40791765]

Minor nit: is this necessary, seems like the pointer value hasn't changed.

[WillChilds-Klein]

are you asking about the PKCS7_dup call on L1207? if so, that's meant to exercise PKCS7_dup and assert that a.) PKCS7_dup duplicates the object without memory leaks and b.) that the duplicated object is of the expected content type.

if asking about the p7_der assignment on L1211, then yes, and nice catch :) it's intentional. d2i_* functions will advance the referenced input pointer during parsing (see comment here). this is why we assign a local pointer to the static address and reset it for relevant tests. OpenSSL documents the generic behavior in this type-specific man page.

d2i_TYPE() attempts to decode len bytes at *ppin. If successful a pointer to the TYPE structure is returned and *ppin is incremented to the byte following the parsed data.

thanks for the call-out, this needs to be documented in a comment.

[samuel40791765]

Ah yes I was asking about p7_der on L1211. It seemed like the d2i functions did some pointer advancements, but the const pointer made me question myself if anything had actually changed. Thanks for the clarification!!

[samuel40791765]

Ah yes I was asking about p7_der on L1211. It seemed like the d2i functions did some pointer advancements, but the const pointer made me question myself if anything had actually changed. Thanks for the clarification!!