Hi Phil, First! Thanks for your time to review my patch! 於 一，2013-09-23 於 19:49 +0300，Phil Carmody 提到： > On Sun, Sep 15, 2013 at 08:56:48AM +0800, Lee, Chun-Yi wrote: > > Implement EMSA_PKCS1-v1_5-ENCODE [RFC3447 sec 9.2] in rsa.c. It's the > > first step of signature generation operation (RSASSA-PKCS1-v1_5-SIGN). > > > > This patch is temporary set emLen to pks->k, and temporary set EM to > > pks->S for debugging. We will replace the above values to real signature > > after implement RSASP1. > > > > The naming of EMSA_PKCS1_v1_5_ENCODE and the variables used in this function > > accord PKCS#1 spec but not follow kernel naming convention, it useful when look > > at them with spec. > > > > Reference: ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-1v2/pkcs1ietffinal.txt > > Reference: http://www.emc.com/collateral/white-papers/h11300-pkcs-1v2-2-rsa-cryptography-standard-wp.pdf > > > > V2: > > You're now at V4. The V4 is for whole patchset, I didn't do any modify in this patch in this version. The version define maybe confuse between separate and whole patchset, I will avoid it. > > > - Clean up naming of variable: replace _EM by EM, replace EM by EM_tmp. > > - Add comment to EMSA_PKCS1-v1_5-ENCODE function. > > > > Cc: Pavel Machek <pavel@xxxxxx> > > Reviewed-by: Jiri Kosina <jkosina@xxxxxxx> > > Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx> > > --- > > crypto/asymmetric_keys/rsa.c | 163 +++++++++++++++++++++++++++++++++++++++++- > > include/crypto/public_key.h | 2 + > > 2 files changed, 164 insertions(+), 1 deletions(-) > > > > diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c > > index 47f3be4..352ba45 100644 > > --- a/crypto/asymmetric_keys/rsa.c > > +++ b/crypto/asymmetric_keys/rsa.c > > @@ -13,6 +13,7 @@ > > #include <linux/module.h> > > #include <linux/kernel.h> > > #include <linux/slab.h> > > +#include <crypto/hash.h> > > #include "public_key.h" > > #include "private_key.h" > > > > @@ -152,6 +153,132 @@ static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X) > > } > > > > /* > > + * EMSA_PKCS1-v1_5-ENCODE [RFC3447 sec 9.2] > > + * @M: message to be signed, an octet string > > + * @emLen: intended length in octets of the encoded message > > + * @hash_algo: hash function (option) > > + * @hash: true means hash M, otherwise M is already a digest > > + * @EM: encoded message, an octet string of length emLen > > + * > > + * This function is a implementation of the EMSA-PKCS1-v1_5 encoding operation > > + * in RSA PKCS#1 spec. It used by the signautre generation operation of > > + * RSASSA-PKCS1-v1_5 to encode message M to encoded message EM. > > + * > > + * The variables used in this function accord PKCS#1 spec but not follow kernel > > + * naming convention, it useful when look at them with spec. > > + */ > > +static int EMSA_PKCS1_v1_5_ENCODE(const u8 *M, size_t emLen, > > + enum pkey_hash_algo hash_algo, const bool hash, > > + u8 **EM, struct public_key_signature *pks) > > +{ > > + u8 *digest; > > + struct crypto_shash *tfm; > > + struct shash_desc *desc; > > + size_t digest_size, desc_size; > > + size_t tLen; > > + u8 *T, *PS, *EM_tmp; > > + int i, ret; > > + > > + pr_info("EMSA_PKCS1_v1_5_ENCODE start\n"); > > + > > + if (!RSA_ASN1_templates[hash_algo].data) > > + ret = -ENOTSUPP; > > ... > > > + else > > + pks->pkey_hash_algo = hash_algo; > > + > > + /* 1) Apply the hash function to the message M to produce a hash value H */ > > + tfm = crypto_alloc_shash(pkey_hash_algo[hash_algo], 0, 0); > > + if (IS_ERR(tfm)) > > + return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm); > > + > > + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); > > + digest_size = crypto_shash_digestsize(tfm); > > + > > + ret = -ENOMEM; > > The earlier "ret = -ENOTSUPP;" is either unused because you return at the IS_ERR, > or unused because you overwrite it here. I'm a little disappointed that > the compiler didn't recognise that something was assigned to a value that > is never used. > > Phil Yes, Dmitry also pointed out this issue, I should not go on the hash process if the hash algorithm didn't support. I will change fix this problem in next version. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
