Implement Octet String to Integer conversion [RFC3447 sec 4.2] in rsa.c. It's the second step of signature generation operation. This patch is temporary set non-RSASP1 message to pks->S for debugging. The naming of RSA_OS2IP 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 Cc: Pavel Machek <pavel@xxxxxx> Reviewed-by: Jiri Kosina <jkosina@xxxxxxx> Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx> --- crypto/asymmetric_keys/rsa.c | 29 ++++++++++++++++++++++++----- 1 files changed, 24 insertions(+), 5 deletions(-) diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c index aac8b77..a092aac 100644 --- a/crypto/asymmetric_keys/rsa.c +++ b/crypto/asymmetric_keys/rsa.c @@ -168,6 +168,20 @@ static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X) } /* + * Octet String to Integer conversion [RFC3447 sec 4.2] + */ +static int RSA_OS2IP(u8 *X, size_t XLen, MPI *_x) +{ + MPI x; + + x = mpi_alloc((XLen + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB); + mpi_set_buffer(x, X, XLen, 0); + + *_x = x; + return 0; +} + +/* * 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 @@ -419,6 +433,9 @@ static struct public_key_signature *RSA_generate_signature( { struct public_key_signature *pks; u8 *EM = NULL; + MPI m = NULL; + MPI s = NULL; + unsigned X_size; size_t emLen; int ret; @@ -438,14 +455,16 @@ static struct public_key_signature *RSA_generate_signature( if (ret < 0) goto error_v1_5_encode; - /* TODO 2): m = OS2IP (EM) */ + /* 2): m = OS2IP (EM) */ + ret = RSA_OS2IP(EM, emLen, &m); + if (ret < 0) + goto error_v1_5_encode; /* TODO 3): s = RSASP1 (K, m) */ + s = m; - /* TODO 4): S = I2OSP (s, k) */ - - /* TODO: signature S to a u8* S or set to sig->rsa.s? */ - pks->S = EM; /* TODO: temporary set S to EM */ + /* 4): S = I2OSP (s, k) */ + _RSA_I2OSP(s, &X_size, &pks->S); return pks; -- 1.6.0.2 -- 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
