git: 7063329b2fc1 - stable/12 - Fortuna: push CTR-mode loop down into randomdev hash.h interface
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Date: Fri, 11 Feb 2022 05:54:52 UTC
The branch stable/12 has been updated by obrien: URL: https://cgit.FreeBSD.org/src/commit/?id=7063329b2fc132f3eebe2680ddf41e85c0fe59c5 commit 7063329b2fc132f3eebe2680ddf41e85c0fe59c5 Author: Conrad Meyer <cem@FreeBSD.org> AuthorDate: 2019-03-01 19:21:45 +0000 Commit: David E. O'Brien <obrien@FreeBSD.org> CommitDate: 2022-02-11 05:47:36 +0000 Fortuna: push CTR-mode loop down into randomdev hash.h interface As a step towards adding other potential streaming ciphers. As well as just pushing the loop down into the rijndael APIs (basically 128-bit wide AES-ICM mode) to eliminate some excess explicit_bzero(). No functional change intended. (cherry picked from commit 51c68d18e2580e5a3949b8c1b331125b71325e0b) --- sys/dev/random/fortuna.c | 16 ++++++---------- sys/dev/random/hash.c | 23 ++++++++++++++++++----- sys/dev/random/hash.h | 4 +++- 3 files changed, 27 insertions(+), 16 deletions(-) diff --git a/sys/dev/random/fortuna.c b/sys/dev/random/fortuna.c index 11879831dbbd..31fcab9e89ff 100644 --- a/sys/dev/random/fortuna.c +++ b/sys/dev/random/fortuna.c @@ -301,20 +301,16 @@ random_fortuna_reseed_internal(uint32_t *entropy_data, u_int blockcount) static __inline void random_fortuna_genblocks(uint8_t *buf, u_int blockcount) { - u_int i; RANDOM_RESEED_ASSERT_LOCK_OWNED(); KASSERT(!uint128_is_zero(fortuna_state.fs_counter), ("FS&K: C != 0")); - for (i = 0; i < blockcount; i++) { - /*- - * FS&K - r = r|E(K,C) - * - C = C + 1 - */ - randomdev_encrypt(&fortuna_state.fs_key, &fortuna_state.fs_counter, buf, RANDOM_BLOCKSIZE); - buf += RANDOM_BLOCKSIZE; - uint128_increment(&fortuna_state.fs_counter); - } + /* + * Fills buf with RANDOM_BLOCKSIZE * blockcount bytes of keystream. + * Increments fs_counter as it goes. + */ + randomdev_keystream(&fortuna_state.fs_key, &fortuna_state.fs_counter, + buf, blockcount); } /*- diff --git a/sys/dev/random/hash.c b/sys/dev/random/hash.c index fe52cd68b848..0bad46519f50 100644 --- a/sys/dev/random/hash.c +++ b/sys/dev/random/hash.c @@ -88,13 +88,26 @@ randomdev_encrypt_init(struct randomdev_key *context, const void *data) rijndael_makeKey(&context->key, DIR_ENCRYPT, RANDOM_KEYSIZE*8, data); } -/* Encrypt the supplied data using the key schedule preset in the context. - * <length> bytes are encrypted from <*d_in> to <*d_out>. <length> must be - * a multiple of RANDOM_BLOCKSIZE. +/* + * Create a psuedorandom output stream of 'blockcount' blocks using a CTR-mode + * cipher or similar. The 128-bit counter is supplied in the in-out parmeter + * 'ctr.' The output stream goes to 'd_out.' 'blockcount' RANDOM_BLOCKSIZE + * bytes are generated. */ void -randomdev_encrypt(struct randomdev_key *context, const void *d_in, void *d_out, u_int length) +randomdev_keystream(struct randomdev_key *context, uint128_t *ctr, + void *d_out, u_int blockcount) { + u_int i; - rijndael_blockEncrypt(&context->cipher, &context->key, d_in, length*8, d_out); + for (i = 0; i < blockcount; i++) { + /*- + * FS&K - r = r|E(K,C) + * - C = C + 1 + */ + rijndael_blockEncrypt(&context->cipher, &context->key, + (void *)ctr, RANDOM_BLOCKSIZE * 8, d_out); + d_out = (char *)d_out + RANDOM_BLOCKSIZE; + uint128_increment(ctr); + } } diff --git a/sys/dev/random/hash.h b/sys/dev/random/hash.h index 41dcf9089f0e..ff24d3fb802d 100644 --- a/sys/dev/random/hash.h +++ b/sys/dev/random/hash.h @@ -29,6 +29,8 @@ #ifndef SYS_DEV_RANDOM_HASH_H_INCLUDED #define SYS_DEV_RANDOM_HASH_H_INCLUDED +#include <dev/random/uint128.h> + /* Keys are formed from cipher blocks */ #define RANDOM_KEYSIZE 32 /* (in bytes) == 256 bits */ #define RANDOM_KEYSIZE_WORDS (RANDOM_KEYSIZE/sizeof(uint32_t)) @@ -52,6 +54,6 @@ void randomdev_hash_init(struct randomdev_hash *); void randomdev_hash_iterate(struct randomdev_hash *, const void *, size_t); void randomdev_hash_finish(struct randomdev_hash *, void *); void randomdev_encrypt_init(struct randomdev_key *, const void *); -void randomdev_encrypt(struct randomdev_key *context, const void *, void *, u_int); +void randomdev_keystream(struct randomdev_key *context, uint128_t *, void *, u_int); #endif /* SYS_DEV_RANDOM_HASH_H_INCLUDED */