[PATCH 4/4] New configure option --disable-crypt.
Florian Weimer
fweimer@redhat.com
Tue May 8 15:00:00 GMT 2018
On 05/06/2018 07:51 PM, Zack Weinberg wrote:
> diff --git a/INSTALL b/INSTALL
> index 052b1b6f89..6de609c9d6 100644
> --- a/INSTALL
> +++ b/INSTALL
> @@ -197,6 +197,17 @@ if 'CFLAGS' is specified it must enable optimization. For example:
> libnss_nisplus are not built at all. Use this option to enable
> libnsl with all depending NSS modules and header files.
>
> +'--disable-crypt'
> + Do not install the password-hashing library 'libcrypt' or the
> + header file 'crypt.h'. 'unistd.h' will still declare the function
> + 'crypt', as required by POSIX. Using this option does not change
> + the set of programs that may need to be linked with '-lcrypt'; it
> + only means that the GNU C Library will not provide that library.
Two spaces after dot; see below.
> + This option is for hackers and distributions experimenting with
> + independently-maintained implementations of libcrypt. It may
> + become the default in a future release.
Okay.
> diff --git a/Makeconfig b/Makeconfig
> index 1afe86475c..608ffe648c 100644
> --- a/Makeconfig
> +++ b/Makeconfig
> @@ -566,7 +566,7 @@ link-libc-printers-tests = $(link-libc-rpath) \
> $(link-libc-tests-after-rpath-link)
>
> # This is how to find at build-time things that will be installed there.
> -rpath-dirs = math elf dlfcn nss nis rt resolv crypt mathvec support
> +rpath-dirs = math elf dlfcn nss nis rt resolv mathvec support
> rpath-link = \
> $(common-objdir):$(subst $(empty) ,:,$(patsubst ../$(subdir),.,$(rpath-dirs:%=$(common-objpfx)%)))
> else # build-static
> @@ -1205,9 +1205,14 @@ all-subdirs = csu assert ctype locale intl catgets math setjmp signal \
> stdlib stdio-common libio malloc string wcsmbs time dirent \
> grp pwd posix io termios resource misc socket sysvipc gmon \
> gnulib iconv iconvdata wctype manual shadow gshadow po argp \
> - crypt localedata timezone rt conform debug mathvec support \
> + localedata timezone rt conform debug mathvec support \
> dlfcn elf
>
> +ifeq ($(build-crypt),yes)
> +all-subdirs += crypt
> +rpath-dirs += crypt
> +endif
Okay.
> ifndef avoid-generated
> # sysd-sorted itself will contain rules making the sysd-sorted target
> # depend on Depend files. But if you just added a Depend file to an
> diff --git a/NEWS b/NEWS
> index 2fe2da8b59..cfc58f71bb 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -71,6 +71,18 @@ Deprecated and removed features, and other changes affecting compatibility:
> encrypt and setkey are not thread-safe. Software that still uses these
> functions should switch to a modern cryptography library, such as GnuTLS.
>
> +* We have tentative plans to deprecate glibc's implementation of the
> + password-hashing functions 'crypt' and 'crypt_r'. We will continue
> + to declare crypt in <unistd.h>, as required by POSIX, and programs
> + that use crypt or crypt_r should not need to change at all. However,
> + the header file <crypt.h> and library libcrypt.{a,so} will come from
> + a separate development project that will, we hope, keep up better with
> + new password-hashing algorithms.
> +
> + In this release, if the configure option --disable-crypt is used,
> + glibc will not install <crypt.h> or libcrypt. The plan is to make
> + this the default behavior in a future release.
Okay.
> diff --git a/config.make.in b/config.make.in
> index 9e5e24b2c6..d9891b2cd8 100644
> --- a/config.make.in
> +++ b/config.make.in
> @@ -96,6 +96,7 @@ cross-compiling = @cross_compiling@
> force-install = @force_install@
> link-obsolete-rpc = @link_obsolete_rpc@
> build-obsolete-nsl = @build_obsolete_nsl@
> +build-crypt = @build_crypt@
> build-nscd = @build_nscd@
> use-nscd = @use_nscd@
> build-hardcoded-path-in-tests= @hardcoded_path_in_tests@
Okay.
> diff --git a/configure b/configure
> index 7a8bd3f817..7317c1aee4 100755
> --- a/configure
> +++ b/configure
Okay (generated file).
> diff --git a/configure.ac b/configure.ac
> index ca1282a6b3..05e03f2f72 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -302,11 +302,22 @@ AC_ARG_ENABLE([experimental-malloc],
> [experimental_malloc=yes])
> AC_SUBST(experimental_malloc)
>
> +AC_ARG_ENABLE([crypt],
> + AC_HELP_STRING([--disable-crypt],
> + [do not build nor install the password hashing library, libcrypt]),
> + [build_crypt=$enableval],
> + [build_crypt=yes])
> +AC_SUBST(build_crypt)
Okay.
> AC_ARG_ENABLE([nss-crypt],
> AC_HELP_STRING([--enable-nss-crypt],
> [enable libcrypt to use nss]),
> [nss_crypt=$enableval],
> [nss_crypt=no])
> +if test x$build_libcrypt = xno && test x$nss_crypt = xyes; then
> + AC_MSG_WARN([--enable-nss-crypt has no effect when libcrypt is disabled])
> + nss_crypt=no
> +fi
Okay.
> if test x$nss_crypt = xyes; then
> nss_includes=-I$(nss-config --includedir 2>/dev/null)
> if test $? -ne 0; then
> diff --git a/conform/Makefile b/conform/Makefile
> index 864fdeca21..74fbda0786 100644
> --- a/conform/Makefile
> +++ b/conform/Makefile
> @@ -193,13 +193,11 @@ linknamespace-libs-thr = $(linknamespace-libs-isoc) \
> $(common-objpfx)rt/librt.a $(static-thread-library)
> linknamespace-libs-posix = $(linknamespace-libs-thr) \
> $(common-objpfx)dlfcn/libdl.a
> -linknamespace-libs-xsi = $(linknamespace-libs-posix) \
> - $(common-objpfx)crypt/libcrypt.a
> +linknamespace-libs-xsi = $(linknamespace-libs-posix)
> linknamespace-libs-ISO = $(linknamespace-libs-isoc)
> linknamespace-libs-ISO99 = $(linknamespace-libs-isoc)
> linknamespace-libs-ISO11 = $(linknamespace-libs-isoc)
> -linknamespace-libs-XPG4 = $(linknamespace-libs-isoc) \
> - $(common-objpfx)crypt/libcrypt.a
> +linknamespace-libs-XPG4 = $(linknamespace-libs-isoc)
> linknamespace-libs-XPG42 = $(linknamespace-libs-XPG4)
> linknamespace-libs-POSIX = $(linknamespace-libs-thr)
> linknamespace-libs-UNIX98 = $(linknamespace-libs-xsi)
> @@ -209,6 +207,11 @@ linknamespace-libs-XOPEN2K8 = $(linknamespace-libs-xsi)
> linknamespace-libs = $(foreach std,$(conformtest-standards),\
> $(linknamespace-libs-$(std)))
>
> +ifeq ($(build-crypt),yes)
> +linknamespace-libs-xsi += $(common-objpfx)crypt/libcrypt.a
> +linknamespace-libs-XPG4 += $(common-objpfx)crypt/libcrypt.a
> +endif
> +
Okay.
> $(linknamespace-symlist-stdlibs-tests): $(objpfx)symlist-stdlibs-%: \
> $(linknamespace-libs)
> LC_ALL=C $(READELF) -W -s $(linknamespace-libs-$*) > $@; \
> diff --git a/crypt/Makefile b/crypt/Makefile
> index e122bcebf0..1e2f21bf52 100644
> --- a/crypt/Makefile
> +++ b/crypt/Makefile
> @@ -35,10 +35,6 @@ tests := cert md5c-test sha256c-test sha512c-test badsalttest
> # cert.c tests the deprecated setkey/encrypt interface
> CFLAGS-cert.c = -Wno-deprecated-declarations
>
> -ifeq ($(crypt-in-libc),yes)
> -routines += $(libcrypt-routines)
> -endif
> -
Okay.
> ifeq ($(nss-crypt),yes)
> nss-cpp-flags := -DUSE_NSS \
> -I$(shell nss-config --includedir) -I$(shell nspr-config --includedir)
> diff --git a/crypt/crypt.h b/crypt/crypt.h
> index 22cf13ff89..4f928901f3 100644
> --- a/crypt/crypt.h
> +++ b/crypt/crypt.h
> @@ -28,7 +28,10 @@
>
> __BEGIN_DECLS
>
> -/* Encrypt at most 8 characters from KEY using salt to perturb DES. */
> +/* Hash a password, KEY, for storage in /etc/shadow. SALT selects the
> + hashing algorithm to be used, and ensures that no two users' passwords
> + are hashed to the same string. The return value points to static
> + storage which will be overwritten by the next call to crypt. */
> extern char *crypt (const char *__key, const char *__salt)
> __THROW __nonnull ((1, 2));
Okay.
> diff --git a/elf/Makefile b/elf/Makefile
> index e658928305..ef9155dbd7 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -385,14 +385,21 @@ $(objpfx)tst-_dl_addr_inside_object: $(objpfx)dl-addr-obj.os
> CFLAGS-tst-_dl_addr_inside_object.c += $(PIE-ccflag)
> endif
>
> -# By default tst-linkall-static should try to use crypt routines to test
> -# static libcrypt use.
> +# We can only test static libcrypt use if libcrypt has been built,
> +# and either NSS crypto is not in use, or static NSS libraries are
> +# available.
> +ifeq ($(build-crypt),no)
> +CFLAGS-tst-linkall-static.c += -DUSE_CRYPT=0
> +else
> +ifeq ($(nss-crypt),no)
> +CFLAGS-tst-linkall-static.c += -DUSE_CRYPT=1
> +else
> +ifeq ($(static-nss-crypt),no)
> +CFLAGS-tst-linkall-static.c += -DUSE_CRYPT=0
> +else
> CFLAGS-tst-linkall-static.c += -DUSE_CRYPT=1
> -# However, if we are using NSS crypto and we don't have a static
> -# library, then we exclude the use of crypt functions in the test.
> -# We similarly exclude libcrypt.a from the static link (see below).
> -ifeq (yesno,$(nss-crypt)$(static-nss-crypt))
> -CFLAGS-tst-linkall-static.c += -UUSE_CRYPT -DUSE_CRYPT=0
> +endif
> +endif
> endif
Okay.
> @@ -1113,7 +1120,6 @@ localplt-built-dso := $(addprefix $(common-objpfx),\
> rt/librt.so \
> dlfcn/libdl.so \
> resolv/libresolv.so \
> - crypt/libcrypt.so \
> )
> ifeq ($(build-mathvec),yes)
> localplt-built-dso += $(addprefix $(common-objpfx), mathvec/libmvec.so)
> @@ -1121,6 +1127,9 @@ endif
> ifeq ($(have-thread-library),yes)
> localplt-built-dso += $(filter-out %_nonshared.a, $(shared-thread-library))
> endif
> +ifeq ($(build-crypt),yes)
> +localplt-built-dso += $(addprefix $(common-objpfx), crypt/libcrypt.so)
> +endif
Okay.
> @@ -1395,6 +1404,7 @@ $(objpfx)tst-linkall-static: \
> $(common-objpfx)resolv/libanl.a \
> $(static-thread-library)
>
> +ifeq ($(build-crypt),yes)
> # If we are using NSS crypto and we have the ability to link statically
> # then we include libcrypt.a, otherwise we leave out libcrypt.a and
> # link as much as we can into the tst-linkall-static test. This assumes
> @@ -1410,6 +1420,7 @@ ifeq (no,$(nss-crypt))
> $(objpfx)tst-linkall-static: \
> $(common-objpfx)crypt/libcrypt.a
> endif
> +endif
Okay.
> # The application depends on the DSO, and the DSO loads the plugin.
> # The plugin also depends on the DSO. This creates the circular
> diff --git a/elf/tst-linkall-static.c b/elf/tst-linkall-static.c
> index e8df38f74e..d0f2592e67 100644
> --- a/elf/tst-linkall-static.c
> +++ b/elf/tst-linkall-static.c
> @@ -18,7 +18,9 @@
>
> #include <math.h>
> #include <pthread.h>
> -#include <crypt.h>
> +#if USE_CRYPT
> +# include <crypt.h>
> +#endif
> #include <resolv.h>
> #include <dlfcn.h>
> #include <utmp.h>
Okay.
> diff --git a/manual/install.texi b/manual/install.texi
> index 4bbbfcffa5..ce2d049f1a 100644
> --- a/manual/install.texi
> +++ b/manual/install.texi
> @@ -230,6 +230,18 @@ libnss_nisplus are not built at all.
> Use this option to enable libnsl with all depending NSS modules and
> header files.
>
> +@item --disable-crypt
> +Do not install the password-hashing library @file{libcrypt} or the
> +header file @file{crypt.h}. @file{unistd.h} will still declare the
> +function @code{crypt}, as required by POSIX. Using this option does
> +not change the set of programs that may need to be linked with
> +@option{-lcrypt}; it only means that @theglibc{} will not provide that
> +library.
You need to use “POSIX@.†instead of “POSIX.†here.
> +This option is for hackers and distributions experimenting with
> +independently-maintained implementations of libcrypt. It may become
> +the default in a future release.
Okay.
> @item --disable-experimental-malloc
> By default, a per-thread cache is enabled in @code{malloc}. While
> this cache can be disabled on a per-application basis using tunables
> diff --git a/posix/unistd.h b/posix/unistd.h
> index 5d4e07f6c8..fdf2d4b208 100644
> --- a/posix/unistd.h
> +++ b/posix/unistd.h
> @@ -1119,10 +1119,11 @@ extern int fdatasync (int __fildes);
> #endif /* Use POSIX199309 */
>
>
> -/* XPG4.2 specifies that prototypes for the encryption functions must
> - be defined here. */
> #ifdef __USE_XOPEN
> -/* Encrypt at most 8 characters from KEY using salt to perturb DES. */
> +/* Hash a password, KEY, for storage in /etc/shadow. SALT selects the
> + hashing algorithm to be used, and ensures that no two users' passwords
> + are hashed to the same string. The return value points to static
> + storage which will be overwritten by the next call to crypt. */
> extern char *crypt (const char *__key, const char *__salt)
> __THROW __nonnull ((1, 2));
Okay.
Thanks,
Florian
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