This implements the worst-case compression size querying interface for 842, based on the logic originally used by pstore.
Signed-off-by: Kees Cook <[email protected]> --- crypto/842.c | 17 ++++++++++++++++- include/linux/sw842.h | 9 +++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/crypto/842.c b/crypto/842.c index bc26dc942821..c6d9ad6512f8 100644 --- a/crypto/842.c +++ b/crypto/842.c @@ -101,6 +101,19 @@ static int crypto842_sdecompress(struct crypto_scomp *tfm, return sw842_decompress(src, slen, dst, dlen); } +static int crypto842_zbufsize(struct crypto_tfm *tfm, + unsigned int slen, unsigned int *dlen) +{ + return sw842_zbufsize(slen, dlen); +} + +static int crypto842_szbufsize(struct crypto_scomp *tfm, + unsigned int slen, unsigned int *dlen, + void *ctx) +{ + return sw842_zbufsize(slen, dlen); +} + static struct crypto_alg alg = { .cra_name = "842", .cra_driver_name = "842-generic", @@ -112,7 +125,8 @@ static struct crypto_alg alg = { .cra_exit = crypto842_exit, .cra_u = { .compress = { .coa_compress = crypto842_compress, - .coa_decompress = crypto842_decompress } } + .coa_decompress = crypto842_decompress, + .coa_zbufsize = crypto842_zbufsize } } }; static struct scomp_alg scomp = { @@ -120,6 +134,7 @@ static struct scomp_alg scomp = { .free_ctx = crypto842_free_ctx, .compress = crypto842_scompress, .decompress = crypto842_sdecompress, + .zbufsize = crypto842_szbufsize, .base = { .cra_name = "842", .cra_driver_name = "842-scomp", diff --git a/include/linux/sw842.h b/include/linux/sw842.h index 3e29f5dcc62b..9760554beb26 100644 --- a/include/linux/sw842.h +++ b/include/linux/sw842.h @@ -10,4 +10,13 @@ int sw842_compress(const u8 *src, unsigned int srclen, int sw842_decompress(const u8 *src, unsigned int srclen, u8 *dst, unsigned int *destlen); +static inline int sw842_zbufsize(unsigned int srclen, + unsigned int *destlen) +{ + /* Worst case is uncompressed sized. */ + *destlen = srclen; + + return 0; +} + #endif -- 2.17.1
