Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
random: vDSO: move prototype of arch chacha function to vdso/getrandom.h
Having the prototype for __arch_chacha20_blocks_nostack in
arch/x86/include/asm/vdso/getrandom.h meant that the prototype and large
doc comment were cloned by every architecture, which has been causing
unnecessary churn. Instead move it into include/vdso/getrandom.h, where
it can be shared by all archs implementing it.
As a side bonus, this then lets us use that prototype in the
vdso_test_chacha self test, to ensure that it matches the source, and
indeed doing so turned up some inconsistencies, which are rectified
here.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+20
-16
-13
arch/x86/include/asm/vdso/getrandom.h
-13
arch/x86/include/asm/vdso/getrandom.h
···
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return &__vdso_rng_data;
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}
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-
/**
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* __arch_chacha20_blocks_nostack - Generate ChaCha20 stream without using the stack.
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* @dst_bytes: Destination buffer to hold @nblocks * 64 bytes of output.
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* @key: 32-byte input key.
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* @counter: 8-byte counter, read on input and updated on return.
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* @nblocks: Number of blocks to generate.
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*
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* Generates a given positive number of blocks of ChaCha20 output with nonce=0, and does not write
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* to any stack or memory outside of the parameters passed to it, in order to mitigate stack data
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* leaking into forked child processes.
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*/
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extern void __arch_chacha20_blocks_nostack(u8 *dst_bytes, const u32 *key, u32 *counter, size_t nblocks);
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-
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#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_VDSO_GETRANDOM_H */
+13
include/vdso/getrandom.h
+13
include/vdso/getrandom.h
···
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bool in_use;
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};
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+
/**
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* __arch_chacha20_blocks_nostack - Generate ChaCha20 stream without using the stack.
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* @dst_bytes: Destination buffer to hold @nblocks * 64 bytes of output.
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* @key: 32-byte input key.
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* @counter: 8-byte counter, read on input and updated on return.
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* @nblocks: Number of blocks to generate.
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+
*
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* Generates a given positive number of blocks of ChaCha20 output with nonce=0, and does not write
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+
* to any stack or memory outside of the parameters passed to it, in order to mitigate stack data
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* leaking into forked child processes.
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*/
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extern void __arch_chacha20_blocks_nostack(u8 *dst_bytes, const u32 *key, u32 *counter, size_t nblocks);
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+
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#endif /* _VDSO_GETRANDOM_H */
+7
-3
tools/testing/selftests/vDSO/vdso_test_chacha.c
+7
-3
tools/testing/selftests/vDSO/vdso_test_chacha.c
···
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#include <sys/random.h>
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#include <string.h>
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#include <stdint.h>
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+
#include <stdbool.h>
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#include "../kselftest.h"
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extern void __arch_chacha20_blocks_nostack(uint8_t *dst_bytes, const uint8_t *key, uint32_t *counter, size_t nblocks);
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+
typedef uint8_t u8;
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typedef uint32_t u32;
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typedef uint64_t u64;
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#include <vdso/getrandom.h>
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int main(int argc, char *argv[])
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{
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enum { TRIALS = 1000, BLOCKS = 128, BLOCK_SIZE = 64 };
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static const uint8_t nonce[8] = { 0 };
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uint32_t counter[2];
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uint8_t key[32];
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+
uint32_t key[8];
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uint8_t output1[BLOCK_SIZE * BLOCKS], output2[BLOCK_SIZE * BLOCKS];
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ksft_print_header();
···
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printf("getrandom() failed!\n");
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return KSFT_SKIP;
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}
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crypto_stream_chacha20(output1, sizeof(output1), nonce, key);
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crypto_stream_chacha20(output1, sizeof(output1), nonce, (uint8_t *)key);
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for (unsigned int split = 0; split < BLOCKS; ++split) {
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memset(output2, 'X', sizeof(output2));
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memset(counter, 0, sizeof(counter));