oysteikt/heimdal
0
0
Fork 0
Code Issues 5 Pull Requests Releases Activity

table-driven checksum

Browse Source 
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@2044 ec53bebd-3082-4978-b11e-865c3cabbd6b
This commit is contained in:
Assar Westerlund
1997-07-08 23:15:33 +00:00
parent 831415cbbe
commit 7cd7046903
1 changed files with 54 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
lib/krb5/checksum.c
View File

@@ -2,6 +2,31 @@
RCSID("$Id$"); RCSID("$Id$");
struct checksum_type {
int type;
size_t checksumsize;
void (*checksum)(void *, size_t, void *);
};
static struct checksum_type cm[] = {
{ CKSUMTYPE_NONE, 0, krb5_NULL_checksum},
{ CKSUMTYPE_CRC32, 4, krb5_CRC_checksum},
{ CKSUMTYPE_RSA_MD4, 16, krb5_MD4_checksum},
{ CKSUMTYPE_RSA_MD5, 16, krb5_MD5_checksum}
};
static int num_ctypes = sizeof(cm) / sizeof(cm[0]);
static struct checksum_type *
find_checksum_type(int ctype)
{
struct checksum_type *c;
for(c = cm; c < cm + num_ctypes; c++)
if(ctype == c->type)
return c;
return NULL;
}
krb5_error_code krb5_error_code
krb5_create_checksum (krb5_context context, krb5_create_checksum (krb5_context context,
krb5_cksumtype type, krb5_cksumtype type,
@@ -9,20 +34,18 @@ krb5_create_checksum (krb5_context context,
size_t len, size_t len,
Checksum *result) Checksum *result)
{ {
struct md4 m; struct checksum_type *c;
if (type != CKSUMTYPE_RSA_MD4) c = find_checksum_type (type);
abort (); if (c == NULL)
return KRB5_PROG_SUMTYPE_NOSUPP;
result->cksumtype = CKSUMTYPE_RSA_MD4; result->cksumtype = type;
result->checksum.length = 16; result->checksum.length = c->checksumsize;
result->checksum.data = malloc(16); result->checksum.data = malloc(result->checksum.length);
if (result->checksum.data == NULL) if(result->checksum.data == NULL)
return ENOMEM; return ENOMEM;
md4_init(&m); (*c->checksum)(ptr, len, result->checksum.data);
md4_update(&m, ptr, len);
md4_finito (&m, result->checksum.data);
return 0; return 0;
} }
@@ -32,18 +55,22 @@ krb5_verify_checksum (krb5_context context,
size_t len, size_t len,
Checksum *cksum) Checksum *cksum)
{ {
struct md4 m; void *tmp;
u_char csum[16]; struct checksum_type *c;
int ret;
if (cksum->cksumtype != CKSUMTYPE_RSA_MD4) c = find_checksum_type (cksum->cksumtype);
return KRB5KRB_AP_ERR_INAPP_CKSUM; if (c == NULL)
if (cksum->checksum.length != 16) return KRB5_PROG_SUMTYPE_NOSUPP;
if (cksum->checksum.length != c->checksumsize)
return KRB5KRB_AP_ERR_MODIFIED; return KRB5KRB_AP_ERR_MODIFIED;
tmp = malloc (c->checksumsize);
md4_init (&m); if (tmp == NULL)
md4_update (&m, ptr, len); return ENOMEM;
md4_finito (&m, csum); (*c->checksum)(ptr, len, tmp);
if (memcmp (cksum->checksum.data, csum, 16) == 0) ret = memcmp (cksum->checksum.data, tmp, c->checksumsize);
free (tmp);
if (ret == 0)
return 0; return 0;
else else
return KRB5KRB_AP_ERR_MODIFIED; return KRB5KRB_AP_ERR_MODIFIED;