From: Selva Nair <selva.n...@gmail.com>
v2: Moved the "parse_hexstring" chunk to a function for clarity
and to permit unit-testing.
A test is submitted as a follow up patch.
Signed-off-by: Selva Nair <selva.n...@gmail.com>
---
src/openvpn/cryptoapi.c | 77 ++++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 40 deletions(-)
diff --git a/src/openvpn/cryptoapi.c b/src/openvpn/cryptoapi.c
index eafef1b1..136c6ffc 100644
--- a/src/openvpn/cryptoapi.c
+++ b/src/openvpn/cryptoapi.c
@@ -180,6 +180,39 @@ err:
return NULL;
}
+/**
+ * Parse a hex string with optional embedded spaces into
+ * a byte array.
+ * @param p pointer to the input string
+ * @param arr on output contains the parsed bytes
+ * @param capacity capacity of the byte array arr
+ * @returns the number of bytes parsed or 0 on error
+ */
+int
+parse_hexstring(const char *p, unsigned char *arr, size_t capacity)
+{
+ int i = 0;
+ for ( ; *p && i < capacity; p += 2)
+ {
+ /* skip spaces */
+ while (*p == ' ')
+ {
+ p++;
+ }
+ if (!*p) /* ending with spaces is not an error */
+ {
+ break;
+ }
+
+ if (!isxdigit(p[0]) || !isxdigit(p[1])
+ || sscanf(p, "%2hhx", &arr[i++]) != 1)
+ {
+ return 0;
+ }
+ }
+ return i;
+}
+
static const CERT_CONTEXT *
find_certificate_in_store(const char *cert_prop, HCERTSTORE cert_store)
{
@@ -210,51 +243,15 @@ find_certificate_in_store(const char *cert_prop,
HCERTSTORE cert_store)
}
else if (!strncmp(cert_prop, "THUMB:", 6))
{
- const char *p;
- int i, x = 0;
find_type = CERT_FIND_HASH;
find_param = &blob;
- /* skip the tag */
- cert_prop += 6;
- for (p = cert_prop, i = 0; *p && i < sizeof(hash); i++)
+ blob.cbData = parse_hexstring(cert_prop + 6, hash, sizeof(hash));
+ if (blob.cbData == 0)
{
- if (*p >= '0' && *p <= '9')
- {
- x = (*p - '0') << 4;
- }
- else if (*p >= 'A' && *p <= 'F')
- {
- x = (*p - 'A' + 10) << 4;
- }
- else if (*p >= 'a' && *p <= 'f')
- {
- x = (*p - 'a' + 10) << 4;
- }
- if (!*++p) /* unexpected end of string */
- {
- msg(M_WARN|M_INFO, "WARNING: cryptoapicert: error parsing
<THUMB:%s>.", cert_prop);
- goto out;
- }
- if (*p >= '0' && *p <= '9')
- {
- x += *p - '0';
- }
- else if (*p >= 'A' && *p <= 'F')
- {
- x += *p - 'A' + 10;
- }
- else if (*p >= 'a' && *p <= 'f')
- {
- x += *p - 'a' + 10;
- }
- hash[i] = x;
- /* skip any space(s) between hex numbers */
- for (p++; *p && *p == ' '; p++)
- {
- }
+ msg(M_WARN|M_INFO, "WARNING: cryptoapicert: error parsing <%s>.",
cert_prop);
+ goto out;
}
- blob.cbData = i;
}
else
{
--
2.34.1
_______________________________________________
Openvpn-devel mailing list
Openvpn-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/openvpn-devel
