diff --git a/src/config/defaults/linux.h b/src/config/defaults/linux.h index 6b24da480..fcdf90400 100644 --- a/src/config/defaults/linux.h +++ b/src/config/defaults/linux.h @@ -14,7 +14,7 @@ #define NAP_LINUX #define SMBIOS_LINUX #define SANBOOT_NULL -#define ENTROPY_NULL +#define ENTROPY_LINUX #define DRIVERS_LINUX diff --git a/src/include/ipxe/entropy.h b/src/include/ipxe/entropy.h index 50ba4fc63..adf325e79 100644 --- a/src/include/ipxe/entropy.h +++ b/src/include/ipxe/entropy.h @@ -54,6 +54,7 @@ typedef uint8_t entropy_sample_t; /* Include all architecture-independent entropy API headers */ #include +#include /* Include all architecture-dependent entropy API headers */ #include diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index 050bf3fec..bfb738a4a 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -247,6 +247,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #define ERRFILE_drbg ( ERRFILE_OTHER | 0x00250000 ) #define ERRFILE_entropy ( ERRFILE_OTHER | 0x00260000 ) #define ERRFILE_rsa ( ERRFILE_OTHER | 0x00270000 ) +#define ERRFILE_linux_entropy ( ERRFILE_OTHER | 0x00280000 ) /** @} */ diff --git a/src/include/ipxe/linux/linux_entropy.h b/src/include/ipxe/linux/linux_entropy.h new file mode 100644 index 000000000..bd89bd52f --- /dev/null +++ b/src/include/ipxe/linux/linux_entropy.h @@ -0,0 +1,32 @@ +#ifndef _IPXE_LINUX_ENTROPY_H +#define _IPXE_LINUX_ENTROPY_H + +/** @file + * + * iPXE entropy API for linux + * + */ + +FILE_LICENCE(GPL2_OR_LATER); + +#ifdef ENTROPY_LINUX +#define ENTROPY_PREFIX_linux +#else +#define ENTROPY_PREFIX_linux __linux_ +#endif + +/** + * min-entropy per sample + * + * @ret min_entropy min-entropy of each sample + */ +static inline __always_inline double +ENTROPY_INLINE ( linux, min_entropy_per_sample ) ( void ) { + + /* We read single bytes from /dev/random and assume that each + * contains full entropy. + */ + return 8; +} + +#endif /* _IPXE_LINUX_ENTROPY_H */ diff --git a/src/interface/linux/linux_entropy.c b/src/interface/linux/linux_entropy.c new file mode 100644 index 000000000..d82aabaad --- /dev/null +++ b/src/interface/linux/linux_entropy.c @@ -0,0 +1,96 @@ +/* + * Copyright (C) 2012 Michael Brown . + * + * 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 of the + * License, or 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +/** @file + * + * Linux entropy source + * + */ + +#include +#include +#include +#include + +/** Entropy source filename */ +static const char entropy_filename[] = "/dev/random"; + +/** Entropy source file handle */ +static int entropy_fd; + +/** + * Enable entropy gathering + * + * @ret rc Return status code + */ +static int linux_entropy_enable ( void ) { + + /* Open entropy source */ + entropy_fd = linux_open ( entropy_filename, O_RDONLY ); + if ( entropy_fd < 0 ) { + DBGC ( &entropy_fd, "ENTROPY could not open %s: %s\n", + entropy_filename, linux_strerror ( linux_errno ) ); + return entropy_fd; + } + + return 0; +} + +/** + * Disable entropy gathering + * + */ +static void linux_entropy_disable ( void ) { + + /* Close entropy source */ + linux_close ( entropy_fd ); +} + +/** + * Get noise sample + * + * @ret noise Noise sample + * @ret rc Return status code + */ +static int linux_get_noise ( noise_sample_t *noise ) { + uint8_t byte; + ssize_t len; + + /* Read a single byte from entropy source */ + len = linux_read ( entropy_fd, &byte, sizeof ( byte ) ); + if ( len < 0 ) { + DBGC ( &entropy_fd, "ENTROPY could not read from %s: %s\n", + entropy_filename, linux_strerror ( linux_errno ) ); + return len; + } + if ( len == 0 ) { + DBGC ( &entropy_fd, "ENTROPY EOF on reading from %s: %s\n", + entropy_filename, linux_strerror ( linux_errno ) ); + return -EPIPE; + } + *noise = byte; + + return 0; +} + +PROVIDE_ENTROPY_INLINE ( linux, min_entropy_per_sample ); +PROVIDE_ENTROPY ( linux, entropy_enable, linux_entropy_enable ); +PROVIDE_ENTROPY ( linux, entropy_disable, linux_entropy_disable ); +PROVIDE_ENTROPY ( linux, get_noise, linux_get_noise );