Arch Linux

Description:
argon2 20171227-1 PKGBUILD uses the Apache license only please switch to or add the CC0 licence.

The code with the exception of src/encoding.c and src/blake2/* are dual licensed CC0 / Apache 2.0
src/encoding.c and src/blake2/* are CC0 only [2] the arch package appears to use src/encoding.c and src/blake2/blake2b.c relicensing them to Apache 2.0

As discussed https://bugs.archlinux.org/task/56703#comment164809 the FSF considers Apache 2.0 incompatible with GPL 2.0 so linking cryptsetup GPL 2.0 with argon2 Apache 2.0
may be problematic depending on Arch's legal position.

[1] From makepkg
Building with optimizations for native
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now src/argon2.c src/core.c src/blake2/blake2b.c src/thread.c src/encoding.c src/opt.c src/run.c -o argon2
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -shared -fPIC -fvisibility=hidden -DA2_VISCTL=1 -Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -Wl,-soname,libargon2.so.1 src/argon2.c src/core.c src/blake2/blake2b.c src/thread.c src/encoding.c src/opt.c -o libargon2.so.1
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/argon2.o src/argon2.c
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/core.o src/core.c
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/blake2/blake2b.o src/blake2/blake2b.c
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/thread.o src/thread.c
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/encoding.o src/encoding.c
cc -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -std=c89 -O3 -Wall -g -Iinclude -Isrc -pthread -march=native -D_FORTIFY_SOURCE=2 -c -o src/opt.o src/opt.c
ar rcs libargon2.a src/argon2.o src/core.o src/blake2/blake2b.o src/thread.o src/encoding.o src/opt.o
[2] https://github.com/P-H-C/phc-winner-argon2/blob/master/README.md