From 26d438457ed1b99b6cb26d8f694e8d3de336f9d8 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 30 Jan 2013 11:30:05 +0200 Subject: digsig: remove unnecessary memory allocation and copying In existing use case, copying of the decoded data is unnecessary in pkcs_1_v1_5_decode_emsa. It is just enough to get pointer to the message. Removing copying and extra buffer allocation. Signed-off-by: Dmitry Kasatkin Signed-off-by: James Morris --- lib/digsig.c | 41 ++++++++++++++--------------------------- 1 file changed, 14 insertions(+), 27 deletions(-) (limited to 'lib') diff --git a/lib/digsig.c b/lib/digsig.c index 8c0e62975c88..0103c5b9b802 100644 --- a/lib/digsig.c +++ b/lib/digsig.c @@ -30,11 +30,10 @@ static struct crypto_shash *shash; -static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg, - unsigned long msglen, - unsigned long modulus_bitlen, - unsigned char *out, - unsigned long *outlen) +static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg, + unsigned long msglen, + unsigned long modulus_bitlen, + unsigned long *outlen) { unsigned long modulus_len, ps_len, i; @@ -42,11 +41,11 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg, /* test message size */ if ((msglen > modulus_len) || (modulus_len < 11)) - return -EINVAL; + return NULL; /* separate encoded message */ - if ((msg[0] != 0x00) || (msg[1] != (unsigned char)1)) - return -EINVAL; + if (msg[0] != 0x00 || msg[1] != 0x01) + return NULL; for (i = 2; i < modulus_len - 1; i++) if (msg[i] != 0xFF) @@ -56,19 +55,13 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg, if (msg[i] != 0) /* There was no octet with hexadecimal value 0x00 to separate ps from m. */ - return -EINVAL; + return NULL; ps_len = i - 2; - if (*outlen < (msglen - (2 + ps_len + 1))) { - *outlen = msglen - (2 + ps_len + 1); - return -EOVERFLOW; - } - *outlen = (msglen - (2 + ps_len + 1)); - memcpy(out, &msg[2 + ps_len + 1], *outlen); - return 0; + return msg + 2 + ps_len + 1; } /* @@ -83,7 +76,8 @@ static int digsig_verify_rsa(struct key *key, unsigned long mlen, mblen; unsigned nret, l; int head, i; - unsigned char *out1 = NULL, *out2 = NULL; + unsigned char *out1 = NULL; + const char *m; MPI in = NULL, res = NULL, pkey[2]; uint8_t *p, *datap, *endp; struct user_key_payload *ukp; @@ -120,7 +114,7 @@ static int digsig_verify_rsa(struct key *key, } mblen = mpi_get_nbits(pkey[0]); - mlen = (mblen + 7)/8; + mlen = DIV_ROUND_UP(mblen, 8); if (mlen == 0) goto err; @@ -129,10 +123,6 @@ static int digsig_verify_rsa(struct key *key, if (!out1) goto err; - out2 = kzalloc(mlen, GFP_KERNEL); - if (!out2) - goto err; - nret = siglen; in = mpi_read_from_buffer(sig, &nret); if (!in) @@ -162,18 +152,15 @@ static int digsig_verify_rsa(struct key *key, memset(out1, 0, head); memcpy(out1 + head, p, l); - err = pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len); - if (err) - goto err; + m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len); - if (len != hlen || memcmp(out2, h, hlen)) + if (!m || len != hlen || memcmp(m, h, hlen)) err = -EINVAL; err: mpi_free(in); mpi_free(res); kfree(out1); - kfree(out2); while (--i >= 0) mpi_free(pkey[i]); err1: -- cgit From 0d2a1b2d03dfd5ee79e7ebc59635690c8f08810f Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 30 Jan 2013 11:30:06 +0200 Subject: mpilib: use DIV_ROUND_UP and remove unused macros Remove MIN, MAX and ABS macros that are duplicates kernel's native implementation. Signed-off-by: Andy Shevchenko Signed-off-by: James Morris --- lib/mpi/mpi-internal.h | 4 ---- lib/mpi/mpicoder.c | 8 ++++---- 2 files changed, 4 insertions(+), 8 deletions(-) (limited to 'lib') diff --git a/lib/mpi/mpi-internal.h b/lib/mpi/mpi-internal.h index 77adcf6bc257..60cf765628e9 100644 --- a/lib/mpi/mpi-internal.h +++ b/lib/mpi/mpi-internal.h @@ -65,10 +65,6 @@ typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */ typedef int mpi_size_t; /* (must be a signed type) */ -#define ABS(x) (x >= 0 ? x : -x) -#define MIN(l, o) ((l) < (o) ? (l) : (o)) -#define MAX(h, i) ((h) > (i) ? (h) : (i)) - static inline int RESIZE_IF_NEEDED(MPI a, unsigned b) { if (a->alloced < b) diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 3962b7f7fe3f..5f9c44cdf1f5 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -52,7 +52,7 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) else nbits = 0; - nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); val = mpi_alloc(nlimbs); if (!val) return NULL; @@ -96,8 +96,8 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) buffer += 2; nread = 2; - nbytes = (nbits + 7) / 8; - nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; + nbytes = DIV_ROUND_UP(nbits, 8); + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); val = mpi_alloc(nlimbs); if (!val) return NULL; @@ -193,7 +193,7 @@ int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign) int nlimbs; int i; - nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB; + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); if (RESIZE_IF_NEEDED(a, nlimbs) < 0) return -ENOMEM; a->sign = sign; -- cgit