4 ms·

> According to Müller, LPRG incorporates four entropy sources that operate completely independent of each other including execution timing jitter and the timing

> According to Müller, LPRG incorporates four entropy sources that operate completely independent of each other including execution timing jitter and the timing of the arrival of interrupts. Can you 'lie' to the operating system about these sources of entropy in order to control the random number generation?

not-elite 5y ago
Of course. https://groups.google.com/g/randomness-generation/c/eNnepJ_65eQ https://groups.google.com/g/randomness-generation/c/eNnepJ_6...
CodeArtisan 5y ago
Last time i checked, /dev/random was receiving entropy from * The kernel command line string at boot. * Every time there is an input event (mouse, keyboard, ...). * Every time there is a disk event. * By retrieving the cpu cycles counter (RDTSC on x86) from random interrupts. * Hardware RNGs(RDRAND on x86). * From latent entropy every time a process is created. Latent entropy is a 64 bits unsigned that has its state modified every time a procedure with the attribute latent_entropy is executed. The latent_entropy attribute is implemented by a GCC plugin and adds random operations on the latent_entropy seed to a procedure. For example void foo(bool a) __attribute__((latent_entropy)) { if (a) bar(); else baz(); } become void foo(bool a) __attribute__((latent_entropy)) { if (a) { latent_entropy OP NUMBER; bar(); } else { latent_entropy OP NUMBER; baz(); } } where OP (*= += -= ^= ...) and NUMBER are randomly generated at compilation time. Many kernel procedures handling interrupts have the latent_entropy attribute. more information at https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/scripts/gcc-plugins/latent_entropy_plugin.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...

not-elite 5y ago

Of course. https://groups.google.com/g/randomness-generation/c/eNnepJ_65eQ https://groups.google.com/g/randomness-generation/c/eNnepJ_6...

CodeArtisan 5y ago

Last time i checked, /dev/random was receiving entropy from * The kernel command line string at boot. * Every time there is an input event (mouse, keyboard, ...). * Every time there is a disk event. * By retrieving the cpu cycles counter (RDTSC on x86) from random interrupts. * Hardware RNGs(RDRAND on x86). * From latent entropy every time a process is created. Latent entropy is a 64 bits unsigned that has its state modified every time a procedure with the attribute latent_entropy is executed. The latent_entropy attribute is implemented by a GCC plugin and adds random operations on the latent_entropy seed to a procedure. For example void foo(bool a) __attribute__((latent_entropy)) { if (a) bar(); else baz(); } become void foo(bool a) __attribute__((latent_entropy)) { if (a) { latent_entropy OP NUMBER; bar(); } else { latent_entropy OP NUMBER; baz(); } } where OP (*= += -= ^= ...) and NUMBER are randomly generated at compilation time. Many kernel procedures handling interrupts have the latent_entropy attribute. more information at https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/scripts/gcc-plugins/latent_entropy_plugin.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...