Mercurial > gnulib
view lib/af_alg.h @ 39342:b50fdee87a36
af_alg: Add ability to use Linux kernel crypto API on data in memory.
* lib/af_alg.h (afalg_buffer): New declaration.
* lib/af_alg.c (afalg_buffer): New function.
author | Bruno Haible <bruno@clisp.org> |
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date | Sun, 06 May 2018 17:04:25 +0200 |
parents | 70fea0441bbe |
children | b9a17c2eedf8 |
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/* af_alg.h - Compute message digests from file streams. Copyright (C) 2018 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, see <https://www.gnu.org/licenses/>. */ /* Written by Matteo Croce <mcroce@redhat.com>, 2018. Documentation by Bruno Haible <bruno@clisp.org>, 2018. */ /* Declare specific functions for computing message digests using the Linux kernel crypto API, if available. This kernel API gives access to specialized crypto instructions (that would also be available in user space) or to crypto devices (not directly available in user space). For a more complete set of facilities that use the Linux kernel crypto API, look at libkcapi. */ #ifndef AF_ALG_H # define AF_ALG_H 1 # include <stdio.h> # include <errno.h> # ifdef __cplusplus extern "C" { # endif # if USE_LINUX_CRYPTO_API /* Compute a message digest of a memory region. The memory region starts at BUFFER and is LEN bytes long. ALG is the message digest algorithm; see the file /proc/crypto. RESBLOCK points to a block of HASHLEN bytes, for the result. HASHLEN must be the length of the message digest, in bytes, in particular: alg | hashlen -------+-------- md5 | 16 sha1 | 20 sha224 | 28 sha256 | 32 sha384 | 48 sha512 | 64 If successful, fill RESBLOCK and return 0. Upon failure, return a negated error number. */ int afalg_buffer (const char *buffer, size_t len, const char *alg, void *resblock, ssize_t hashlen); /* Compute a message digest of the contents of a file. STREAM is an open file stream. Regular files are handled more efficiently. The contents of STREAM from its current position to its end will be read. The case that the last operation on STREAM was an 'ungetc' is not supported. ALG is the message digest algorithm; see the file /proc/crypto. RESBLOCK points to a block of HASHLEN bytes, for the result. HASHLEN must be the length of the message digest, in bytes, in particular: alg | hashlen -------+-------- md5 | 16 sha1 | 20 sha224 | 28 sha256 | 32 sha384 | 48 sha512 | 64 If successful, fill RESBLOCK and return 0. Upon failure, return a negated error number. */ int afalg_stream (FILE *stream, const char *alg, void *resblock, ssize_t hashlen); # else static inline int afalg_buffer (const char *buffer, size_t len, const char *alg, void *resblock, ssize_t hashlen) { return -EAFNOSUPPORT; } static inline int afalg_stream (FILE *stream, const char *alg, void *resblock, ssize_t hashlen) { return -EAFNOSUPPORT; } # endif # ifdef __cplusplus } # endif #endif /* AF_ALG_H */