Math functions for large vector based numbers

[LordofGhost]

Describe your changes

This pull request includes several changes to improve the RSA key management and encryption functionality. The key changes involve renaming files and namespaces, adding header guards, and implementing new functions for base64 encoding and decoding.

Key changes:

File Renaming and Namespace Updates:

• Renamed keys.cpp to key.cpp in src/CMakeLists.txt and updated corresponding includes and namespace references in src/cli.cpp, src/cli.h, and src/main.cpp. [1] [2] [3] [4]

Header Guards:

• Added header guards to src/cli.h, src/encryption.h, src/utility.h, and src/vec/operations.h to prevent multiple inclusions. [1] [2] [3] [4]

Key Management Enhancements:

• Implemented new functions for base64 encoding and decoding in src/key.cpp and updated the key writing and reading functions to use std::vector<uint8_t> for storing key data. [1] [2]
• Added a new constant base64Chars for the base64 character set and updated the key creation and retrieval functions to use std::vector<uint8_t> in src/key.h.

Code Cleanup:

• Removed the old keys.cpp and keys.h files and their contents, as they have been replaced by the new key.cpp and key.h files. [1] [2]

Vector Operations:

• Added new vector operations functions in the operations namespace in src/vec/operations.h, including functions for bit manipulation and comparison. [1] [2]

Tested platforms

• Windows (x86/32-Bit)
• Windows (64-Bit)
• Ubuntu (20.04 LTS or above)
• macOS (Apple Silicon)

Issue ticket number if there is one