Various PKCS12 Fixes

[rlm2002]

Description

• Fix cast to int. - wc_d2i_PKCS12 casts int* to word32* violating strict aliasing and breaking on 16-bit platforms (F-1544)
• Zeroize buffers - PKCS12 PBKDF Missing ForceZero on Password-Containing Buffer (F- 1255), PKCS12 Parse Decrypted Private Key Buffer Freed Without ForceZero (F-1993)
• Check buffer bounds - PKCS12 and wc_CryptKey Unicode Password Size Check Integer Overflow Bypasses Stack Buffer Bounds Check (F-2244), PKCS12 and wc_CryptKey Unicode Password Size Check Integer Overflow Bypasses Stack Buffer Bounds Check (F-2245)

Also incorporates fixes for an issue internally found by AI and one in 10233

Testing

./configure --enable-all && make check

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[github-actions]

MemBrowse Memory Report

No memory changes detected for:

• gcc-arm-cortex-m4
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-tls12