Adding a few more mentioned in the replies:

Vita3k: https://github.com/Vita3K/Vita3K/blob/master/vita3k/packages/src/sce_utils.cpp#L39
Ryujinx: https://github.com/Thealexbarney/LibHac/blob/master/build/CodeGen/IncludedKeys.txt
melonDS: https://github.com/melonDS-emu/melonDS/blob/master/src/DSi_AES.cpp#L141
no$gba: not open source, you can compare https://gist.github.com/delroth/4fb0528a2306147a38a89817c3ef304c from a quick disasm with melonDS above