doxygen should be ported to use NSS library for cryptography. See the tracking bug for details and links on how it could be done.
doygen doesn't use any non-trivial crypt rpm -q --requires doxygen libc.so.6 libc.so.6(GLIBC_2.0) libc.so.6(GLIBC_2.1) libc.so.6(GLIBC_2.1.3) libc.so.6(GLIBC_2.3.4) libc.so.6(GLIBC_2.4) libgcc_s.so.1 libgcc_s.so.1(GCC_3.0) libm.so.6 libpng12.so.0 libpng12.so.0(PNG12_0) libstdc++.so.6 libstdc++.so.6(CXXABI_1.3) libstdc++.so.6(GLIBCXX_3.4) rpmlib(CompressedFileNames) <= 3.0.4-1 rpmlib(PayloadFilesHavePrefix) <= 4.0-1 rtld(GNU_HASH)