The current CRYPTO API supports one-shot (de)compression only, i.e. the whole
data buffer to be (de)compressed must be passed at once, and the whole
(de)compressed data buffer will be received at once.
In several use-cases (e.g. compressed file systems that store files in big
compressed blocks), this workflow is not suitable. Hence the CRYPTO API cannot
be used.
To solve this, add the following operations that support partial
(de)compression:
- crypto_compress_{init,update,final}() for compression,
- crypto_decompress_{init,update,final}() for decompression.
All these methods take a struct comp_request, which was mimicked after the
z_stream object in zlib, and contains buffer pointer and length pairs for input
and output.
Issues:
- Some underlying (de)compression implementations do not support partial
(de)compression. This is the case for e.g. LZO, which is already supported
by a crypto module. While one-shot (de)compression can easily be
implemented on top of a partial (de)compression API, the inverse is not
true.
Hence there should be a way to ask for a "one-shot" vs. "partial"
decompression module at crypto_alloc_comp() time.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@xxxxxxxxxxx>
---
crypto/compress.c | 45 +++++++++++++++++++++++++++
include/linux/crypto.h | 79 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 123 insertions(+), 1 deletion(-)
diff --git a/crypto/compress.c b/crypto/compress.c
index 1ee3570..9dbe6f6 100644
--- a/crypto/compress.c
+++ b/crypto/compress.c
@@ -33,13 +33,56 @@ static int crypto_decompress(struct crypto_tfm *tfm,
dlen);
}
+static int crypto_compress_init(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_compress_init(tfm, req);
+}
+
+static int crypto_compress_update(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_compress_update(tfm, req);
+}
+
+static int crypto_compress_final(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_compress_final(tfm, req);
+}
+
+static int crypto_decompress_init(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_decompress_init(tfm, req);
+}
+
+static int crypto_decompress_update(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_decompress_update(tfm, req);
+}
+
+static int crypto_decompress_final(struct crypto_tfm *tfm,
+ struct comp_request *req)
+{
+ return tfm->__crt_alg->cra_compress.coa_decompress_final(tfm, req);
+}
+
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_compress_init = crypto_compress_init;
+ ops->cot_compress_update = crypto_compress_update;
+ ops->cot_compress_final = crypto_compress_final;
+ ops->cot_decompress_init = crypto_decompress_init;
+ ops->cot_decompress_update = crypto_decompress_update;
+ ops->cot_decompress_final = crypto_decompress_final;
+
return 0;
}
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 3d2317e..cef556e 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -180,6 +180,13 @@ struct aead_request {
void *__ctx[] CRYPTO_MINALIGN_ATTR;
};
+struct comp_request {
+ const void *next_in; /* next input byte */
+ void *next_out; /* next output byte */
+ unsigned int avail_in; /* bytes available at next_in */
+ unsigned int avail_out; /* bytes available at next_out */
+};
+
struct blkcipher_desc {
struct crypto_blkcipher *tfm;
void *info;
@@ -294,10 +301,24 @@ struct hash_alg {
};
struct compress_alg {
+ /* one shot */
int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
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);
+ /* partial */
+ int (*coa_compress_init)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*coa_compress_update)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*coa_compress_final)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*coa_decompress_init)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*coa_decompress_update)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*coa_decompress_final)(struct crypto_tfm *tfm,
+ struct comp_request *req);
};
struct rng_alg {
@@ -443,12 +464,26 @@ struct ahash_tfm {
};
struct compress_tfm {
+ /* one shot */
int (*cot_compress)(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen);
int (*cot_decompress)(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen);
+ /* partial */
+ int (*cot_compress_init)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*cot_compress_update)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*cot_compress_final)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*cot_decompress_init)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*cot_decompress_update)(struct crypto_tfm *tfm,
+ struct comp_request *req);
+ int (*cot_decompress_final)(struct crypto_tfm *tfm,
+ struct comp_request *req);
};
struct rng_tfm {
@@ -1323,6 +1358,7 @@ static inline struct compress_tfm *crypto_comp_crt(struct crypto_comp *tfm)
return &crypto_comp_tfm(tfm)->crt_compress;
}
+/* one shot */
static inline int crypto_comp_compress(struct crypto_comp *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
@@ -1339,5 +1375,48 @@ static inline int crypto_comp_decompress(struct crypto_comp *tfm,
src, slen, dst, dlen);
}
+/* partial */
+static inline int crypto_comp_compress_init(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_compress_init(crypto_comp_tfm(tfm),
+ req);
+}
+
+static inline int crypto_comp_compress_update(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_compress_update(crypto_comp_tfm(tfm),
+ req);
+}
+
+static inline int crypto_comp_compress_final(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_compress_final(crypto_comp_tfm(tfm),
+ req);
+}
+
+static inline int crypto_comp_decompress_init(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_decompress_init(crypto_comp_tfm(tfm),
+ req);
+}
+
+static inline int crypto_comp_decompress_update(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_decompress_update(crypto_comp_tfm(tfm),
+ req);
+}
+
+static inline int crypto_comp_decompress_final(struct crypto_comp *tfm,
+ struct comp_request *req)
+{
+ return crypto_comp_crt(tfm)->cot_decompress_final(crypto_comp_tfm(tfm),
+ req);
+}
+
#endif /* _LINUX_CRYPTO_H */
With kind regards,
Geert Uytterhoeven
Software Architect
Sony Techsoft Centre Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium
Phone: +32 (0)2 700 8453
Fax: +32 (0)2 700 8622
E-mail: Geert.Uytterhoeven@xxxxxxxxxxx
Internet: http://www.sony-europe.com/
A division of Sony Europe (Belgium) N.V.
VAT BE 0413.825.160 · RPR Brussels
Fortis · BIC GEBABEBB · IBAN BE41293037680010
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