RC2 is deprecated by OpenSSL 3.2.0

[nightkr]

From https://www.openssl.org/news/cl32.txt:

• The implementation of older EVP ciphers related to CAST, IDEA, SEED, RC2, RC4,
  RC5, DESX and DES have been moved to the legacy provider.

In practice, this means that trying to open an encrypted PKCS#12 bundle generated by p12::EncryptedData::from_safe_bags using OpenSSL will fail:

$ openssl pkcs12 -in truststore.p12 
Enter Import Password:
Error outputting keys and certificates
40976AB7AB730000:error:0308010C:digital envelope routines:inner_evp_generic_fetch:unsupported:../crypto/evp/evp_fetch.c:373:Global default library context, Algorithm (RC2-40-CBC : 0), Properties ()

This can be worked around by using the -legacy flag:

$ openssl pkcs12 -in truststore.p12 -legacy | head -n5
Enter Import Password:
Bag Attributes
    2.16.840.1.113894.746875.1.1: <No Values>
subject=CN = secret-operator self-signed
issuer=CN = secret-operator self-signed
-----BEGIN CERTIFICATE-----
[snip]

However, it would still be good to switch to a more modern algorithm.

[nightkr]

Modern OpenSSL defaults to AES-256-CBC and PBKDF2, that seems like a good lead to follow.