diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/digsig.c | 41 |
1 files changed, 14 insertions, 27 deletions
diff --git a/lib/digsig.c b/lib/digsig.c index 8c0e629..0103c5b 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: |
