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Lines 40-45
Author: Ralph Mor, X Consortium
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#include <bsd/stdlib.h> /* for arc4random_buf() */ |
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#include <bsd/stdlib.h> /* for arc4random_buf() */ |
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#endif |
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#endif |
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#ifndef HAVE_GETENTROPY |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <fcntl.h> |
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#include <errno.h> |
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#include <linux/random.h> |
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#include <sys/syscall.h> |
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#endif |
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static int was_called_state; |
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static int was_called_state; |
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#ifndef HAVE_ARC4RANDOM_BUF |
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#ifndef HAVE_ARC4RANDOM_BUF |
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Lines 78-97
emulate_getrandom_buf (
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} |
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} |
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} |
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} |
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#ifndef HAVE_GETENTROPY |
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static int |
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emulate_getentropy |
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( |
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void *buffer, |
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size_t length |
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) |
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{ |
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int random_fd = -1; |
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int res; |
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size_t filled = 0; |
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int use_getrandom = 1; |
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if( length > 256 ) { |
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errno = EIO; |
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return -1; |
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} |
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/* try getrandom() first */ |
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res = syscall(SYS_getrandom, (char*)buffer, length, 0); |
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if( (res == -1) && (errno == ENOSYS)) { |
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/* fallback to /dev/urandrom */ |
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random_fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); |
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if( random_fd == -1 ) { |
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return -1; |
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} |
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/* use /dev/urandom further on */ |
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use_getrandom = 0; |
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} |
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while( filled < length ) { |
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if (use_getrandom) { |
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/* |
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* glibc does not contain a syscall wrapper for this in older |
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* versions |
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*/ |
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res = syscall(SYS_getrandom, (char*)buffer + filled, length - filled, 0); |
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} else { |
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res = read(random_fd, (char*)buffer + filled, length - filled); |
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} |
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if( res == -1 ) { |
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if( errno == EINTR ) |
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continue; |
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return -1; |
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} else if ( res == 0 ) { |
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// no more bytes available? should not happen |
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errno = EIO; |
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return -1; |
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} |
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filled += res; |
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} |
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return 0; |
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} |
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#endif |
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static void |
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static void |
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arc4random_buf ( |
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arc4random_buf ( |
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char *auth, |
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char *auth, |
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int len |
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int len |
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) |
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) |
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{ |
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{ |
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int ret; |
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int ret = -1; |
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#if HAVE_GETENTROPY |
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#if HAVE_GETENTROPY |
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/* weak emulation of arc4random through the entropy libc */ |
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/* weak emulation of arc4random through the entropy libc */ |
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ret = getentropy (auth, len); |
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ret = getentropy (auth, len); |
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#else |
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/* drop-in replacement for getentropy() using getrandom() or /dev/urandom directly */ |
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ret = emulate_getentropy(auth, len); |
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#endif /* HAVE_GETENTROPY */ |
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if (ret == 0) |
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if (ret == 0) |
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return; |
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return; |
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#endif /* HAVE_GETENTROPY */ |
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emulate_getrandom_buf (auth, len); |
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emulate_getrandom_buf (auth, len); |
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} |
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} |