krb5 commit: Refactor krb5_string_to_keysalts()
Tom Yu
tlyu at MIT.EDU
Wed Jan 8 17:06:53 EST 2014
https://github.com/krb5/krb5/commit/0918990bf1d8560d74473fc0e41d08d433da1a15
commit 0918990bf1d8560d74473fc0e41d08d433da1a15
Author: Tom Yu <tlyu at mit.edu>
Date: Tue Jan 7 16:37:46 2014 -0500
Refactor krb5_string_to_keysalts()
Use various standard C library functions rather than rolling our own.
Previous code spent many lines reimplementing realloc(), strpbrk(),
strtok_r(), etc.
Make a separate string_to_keysalt() parser for an individual keysalt
pair, which for now is private and destructive.
src/lib/kadm5/str_conv.c | 179 ++++++++++++++++-----------------------------
1 files changed, 64 insertions(+), 115 deletions(-)
diff --git a/src/lib/kadm5/str_conv.c b/src/lib/kadm5/str_conv.c
index 83d081e..e8de915 100644
--- a/src/lib/kadm5/str_conv.c
+++ b/src/lib/kadm5/str_conv.c
@@ -246,6 +246,30 @@ krb5_keysalt_is_present(ksaltlist, nksalts, enctype, salttype)
return(foundit);
}
+/* NOTE: This is a destructive parser (writes NULs). */
+static krb5_error_code
+string_to_keysalt(char *s, const char *ksaltseps,
+ krb5_enctype *etype, krb5_int32 *stype)
+{
+ char *sp;
+ const char *ksseps = (ksaltseps != NULL) ? ksaltseps : default_ksaltseps;
+ krb5_error_code ret = 0;
+
+ sp = strpbrk(s, ksseps);
+ if (sp != NULL) {
+ *sp++ = '\0';
+ }
+ ret = krb5_string_to_enctype(s, etype);
+ if (ret)
+ return ret;
+
+ /* Default to normal salt if omitted. */
+ *stype = KRB5_KDB_SALTTYPE_NORMAL;
+ if (sp == NULL)
+ return 0;
+ return krb5_string_to_salttype(sp, stype);
+}
+
/*
* krb5_string_to_keysalts() - Convert a string representation to a list
* of key/salt tuples.
@@ -255,123 +279,48 @@ krb5_string_to_keysalts(const char *string, const char *tupleseps,
const char *ksaltseps, krb5_boolean dups,
krb5_key_salt_tuple **ksaltp, krb5_int32 *nksaltp)
{
- krb5_error_code kret;
- char *dup_string, *kp, *sp, *ep;
- char sepchar = 0, trailchar = 0;
- krb5_enctype ktype;
- krb5_int32 stype;
- krb5_key_salt_tuple *savep;
- const char *tseplist;
- const char *ksseplist;
- const char *septmp;
- size_t len;
-
- kret = 0;
- dup_string = strdup(string);
- if (dup_string == NULL)
+ char *p, *ksp;
+ char *tlasts = NULL;
+ const char *tseps = (tupleseps != NULL) ? tupleseps : default_tupleseps;
+ krb5_int32 nksalts = 0;
+ krb5_int32 stype;
+ krb5_enctype etype;
+ krb5_error_code ret = 0;
+ krb5_key_salt_tuple *ksalts = NULL, *ksalts_new = NULL;
+
+ *ksaltp = NULL;
+ *nksaltp = 0;
+ p = strdup(string);
+ if (p == NULL)
return ENOMEM;
- kp = dup_string;
- tseplist = (tupleseps) ? tupleseps : default_tupleseps;
- ksseplist = (ksaltseps) ? ksaltseps : default_ksaltseps;
- while (kp) {
- /* Attempt to find a separator */
- ep = (char *) NULL;
- if (*tseplist) {
- septmp = tseplist;
- for (ep = strchr(kp, (int) *septmp);
- *(++septmp) && !ep;
- ep = strchr(kp, (int) *septmp));
- }
-
- if (ep) {
- trailchar = *ep;
- *ep = '\0';
- ep++;
+ ksp = strtok_r(p, tseps, &tlasts);
+ while (ksp != NULL) {
+ ret = string_to_keysalt(ksp, ksaltseps, &etype, &stype);
+ if (ret)
+ goto cleanup;
+
+ /* Ignore duplicate keysalts if caller asks. */
+ if (!dups && krb5_keysalt_is_present(ksalts, nksalts, etype, stype))
+ continue;
+
+ ksalts_new = realloc(ksalts, (nksalts + 1) * sizeof(*ksalts));
+ if (ksalts_new == NULL) {
+ ret = ENOMEM;
+ goto cleanup;
}
- /*
- * kp points to something (hopefully) of the form:
- * <enctype><ksseplist><salttype>
- * or
- * <enctype>
- */
- sp = (char *) NULL;
- /* Attempt to find a separator */
- septmp = ksseplist;
- for (sp = strchr(kp, (int) *septmp);
- *(++septmp) && !sp;
- sp = strchr(kp, (int) *septmp));
-
- if (sp) {
- /* Separate enctype from salttype */
- sepchar = *sp;
- *sp = '\0';
- sp++;
- }
- else
- stype = KRB5_KDB_SALTTYPE_NORMAL;
-
- /*
- * Attempt to parse enctype and salttype. If we parse well
- * then make sure that it specifies a unique key/salt combo
- */
- if (!(kret = krb5_string_to_enctype(kp, &ktype)) &&
- (!sp || !(kret = krb5_string_to_salttype(sp, &stype))) &&
- (dups ||
- !krb5_keysalt_is_present(*ksaltp, *nksaltp, ktype, stype))) {
-
- /* Squirrel away old keysalt array */
- savep = *ksaltp;
- len = (size_t) *nksaltp;
-
- /* Get new keysalt array */
- *ksaltp = (krb5_key_salt_tuple *)
- malloc((len + 1) * sizeof(krb5_key_salt_tuple));
- if (*ksaltp) {
-
- /* Copy old keysalt if appropriate */
- if (savep) {
- memcpy(*ksaltp, savep,
- len * sizeof(krb5_key_salt_tuple));
- free(savep);
- }
-
- /* Save our values */
- (*ksaltp)[(*nksaltp)].ks_enctype = ktype;
- (*ksaltp)[(*nksaltp)].ks_salttype = stype;
- (*nksaltp)++;
- }
- else {
- *ksaltp = savep;
- break;
- }
- }
- if (kret) {
- free(dup_string);
- return kret;
- }
- if (sp)
- sp[-1] = sepchar;
- if (ep)
- ep[-1] = trailchar;
- kp = ep;
-
- /* Skip over extra separators - like spaces */
- if (kp && *tseplist) {
- septmp = tseplist;
- while(*septmp && *kp) {
- if(*septmp == *kp) {
- /* Increment string - reset separator list */
- kp++;
- septmp = tseplist;
- } else {
- septmp++;
- }
- }
- if (!*kp) kp = NULL;
- }
- } /* while kp */
- free(dup_string);
- return(kret);
+ ksalts = ksalts_new;
+ ksalts[nksalts].ks_enctype = etype;
+ ksalts[nksalts].ks_salttype = stype;
+ nksalts++;
+ ksp = strtok_r(NULL, tseps, &tlasts);
+ }
+ *ksaltp = ksalts;
+ *nksaltp = nksalts;
+cleanup:
+ if (ret)
+ free(ksalts);
+ free(p);
+ return ret;
}
/*
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