Linux From Scratch - Version 12.1-systemd-rc1

Chapter 8. Installing Basic System Software

8.26. Libxcrypt-4.4.36

The Libxcrypt package contains a modern library for one-way hashing of passwords.

Approximate build time: 0.1 SBU
Required disk space: 15 MB

8.26.1. Installation of Libxcrypt

Prepare Libxcrypt for compilation: 

./configure --prefix=/usr                \
            --enable-hashes=strong,glibc \
            --enable-obsolete-api=no     \
            --disable-static             \
            --disable-failure-tokens

The meaning of the new configure options:

--enable-hashes=strong,glibc

Build strong hash algorithms recommended for security use cases, and the hash algorithms provided by traditional Glibc libcrypt for compatibility.

--enable-obsolete-api=no

Disable obsolete API functions. They are not needed for a modern Linux system built from source.

--disable-failure-tokens

Disable failure token feature. It's needed for compatibility with the traditional hash libraries of some platforms, but a Linux system based on Glibc does not need it.

Compile the package: 

make

To test the results, issue: 

make check

Install the package: 

make install
[Note]

Note

The instructions above disabled obsolete API functions since no package installed by compiling from sources would link against them at runtime. However, the only known binary-only applications that link against these functions require ABI version 1. If you must have such functions because of some binary-only application or to be compliant with LSB, build the package again with the following commands: 

make distclean
./configure --prefix=/usr                \
            --enable-hashes=strong,glibc \
            --enable-obsolete-api=glibc  \
            --disable-static             \
            --disable-failure-tokens
make
cp -av .libs/libcrypt.so.1* /usr/lib

8.26.2. Contents of Libxcrypt

Installed libraries: libcrypt.so

Short Descriptions

libcrypt

Contains functions to hash passwords