[PATCH 1/9] crypto: add zbufsize() interface
From: Kees Cook <hidden>
Date: 2018-08-02 21:52:24
Also in:
lkml
Subsystem:
crypto api, the rest · Maintainers:
Herbert Xu, "David S. Miller", Linus Torvalds
When pstore was refactored to use the crypto compress API in:
commit cb3bee0369bc ("pstore: Use crypto compress API")
nearly all the pstore-specific compression routines were replaced with
the existing crypto compression API. One case remained: calculating the
"worst case" compression sizes ahead of time so it could have a buffer
preallocated for doing compression (which was called "zbufsize").
To make pstore fully algorithm-agnostic, the compression API needs to
grow this functionality. This adds the interface to support querying the
"worst case" estimate, with a new "zbufsize" routine that each compressor
can implement. The per-compressor implementations come in later commits.
Signed-off-by: Kees Cook <redacted>
---
crypto/compress.c | 9 +++++++++
include/crypto/internal/scompress.h | 11 +++++++++++
include/linux/crypto.h | 12 ++++++++++++
3 files changed, 32 insertions(+)
diff --git a/crypto/compress.c b/crypto/compress.c
index f2d522924a07..29a80bb3b9d3 100644
--- a/crypto/compress.c
+++ b/crypto/compress.c@@ -33,12 +33,21 @@ static int crypto_decompress(struct crypto_tfm *tfm, dlen); } +static int crypto_zbufsize(struct crypto_tfm *tfm, + unsigned int slen, unsigned int *dlen) +{ + if (!tfm->__crt_alg->cra_compress.coa_zbufsize) + return -ENOTSUPP; + return tfm->__crt_alg->cra_compress.coa_zbufsize(tfm, slen, dlen); +} + int crypto_init_compress_ops(struct crypto_tfm *tfm) { struct compress_tfm *ops = &tfm->crt_compress; ops->cot_compress = crypto_compress; ops->cot_decompress = crypto_decompress; + ops->cot_zbufsize = crypto_zbufsize; return 0; }
diff --git a/include/crypto/internal/scompress.h b/include/crypto/internal/scompress.h
index 0f6ddac1acfc..a4a2a55080ad 100644
--- a/include/crypto/internal/scompress.h
+++ b/include/crypto/internal/scompress.h@@ -39,6 +39,8 @@ struct scomp_alg { int (*decompress)(struct crypto_scomp *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen, void *ctx); + int (*zbufsize)(struct crypto_scomp *tfm, unsigned int slen, + unsigned int *dlen, void *ctx); struct crypto_alg base; };
@@ -94,6 +96,15 @@ static inline int crypto_scomp_decompress(struct crypto_scomp *tfm, ctx); } +static inline int crypto_scomp_zbufsize(struct crypto_scomp *tfm, + unsigned int slen, + unsigned int *dlen, void *ctx) +{ + if (!crypto_scomp_alg(tfm)->zbufsize) + return -ENOTSUPP; + return crypto_scomp_alg(tfm)->zbufsize(tfm, slen, dlen, ctx); +} + int crypto_init_scomp_ops_async(struct crypto_tfm *tfm); struct acomp_req *crypto_acomp_scomp_alloc_ctx(struct acomp_req *req); void crypto_acomp_scomp_free_ctx(struct acomp_req *req);
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 6eb06101089f..376c056447e7 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h@@ -362,6 +362,8 @@ struct compress_alg { unsigned int slen, u8 *dst, unsigned int *dlen); int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen); + int (*coa_zbufsize)(struct crypto_tfm *tfm, unsigned int slen, + unsigned int *dlen); };
@@ -578,6 +580,8 @@ struct compress_tfm { int (*cot_decompress)(struct crypto_tfm *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int *dlen); + int (*cot_zbufsize)(struct crypto_tfm *tfm, + unsigned int slen, unsigned int *dlen); }; #define crt_ablkcipher crt_u.ablkcipher
@@ -1660,5 +1664,13 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm, src, slen, dst, dlen); } +static inline int crypto_comp_zbufsize(struct crypto_comp *tfm, + unsigned int slen, + unsigned int *dlen) +{ + return crypto_comp_crt(tfm)->cot_zbufsize(crypto_comp_tfm(tfm), + slen, dlen); +} + #endif /* _LINUX_CRYPTO_H */
--
2.17.1