1 files changed, 16 insertions, 22 deletions
diff --git a/src/ltc/pk/asn1/der/utf8/der_decode_utf8_string.c b/src/ltc/pk/asn1/der/utf8/der_decode_utf8_string.c
index d857ce95..c86d6603 100644
--- a/src/ltc/pk/asn1/der/utf8/der_decode_utf8_string.c
+++ b/src/ltc/pk/asn1/der/utf8/der_decode_utf8_string.c
@@ -29,6 +29,7 @@ int der_decode_utf8_string(const unsigned char *in,  unsigned long inlen,
 {
    wchar_t       tmp;
    unsigned long x, y, z, len;
+   int err;
 
    LTC_ARGCHK(in     != NULL);
    LTC_ARGCHK(out    != NULL);
@@ -45,25 +46,14 @@ int der_decode_utf8_string(const unsigned char *in,  unsigned long inlen,
    }
    x = 1;
 
-   /* decode the length */
-   if (in[x] & 0x80) {
-      /* valid # of bytes in length are 1,2,3 */
-      y = in[x] & 0x7F;
-      if ((y == 0) || (y > 3) || ((x + y) > inlen)) {
-         return CRYPT_INVALID_PACKET;
-      }
-
-      /* read the length in */
-      len = 0;
-      ++x;
-      while (y--) {
-         len = (len << 8) | in[x++];
-      }
-   } else {
-      len = in[x++] & 0x7F;
+   /* get the length of the data */
+   y = inlen - x;
+   if ((err = der_decode_asn1_length(in + x, &y, &len)) != CRYPT_OK) {
+      return err;
    }
+   x += y;
 
-   if (len + x > inlen) {
+   if (len > (inlen - x)) {
       return CRYPT_INVALID_PACKET;
    }
 
@@ -91,15 +81,19 @@ int der_decode_utf8_string(const unsigned char *in,  unsigned long inlen,
          tmp = (tmp << 6) | ((wchar_t)in[x++] & 0x3F);
       }
 
-      if (y > *outlen) {
-         *outlen = y;
-         return CRYPT_BUFFER_OVERFLOW;
+      if (y < *outlen) {
+         out[y] = tmp;
       }
-      out[y++] = tmp;
+      y++;
+   }
+   if (y > *outlen) {
+      err = CRYPT_BUFFER_OVERFLOW;
+   } else {
+      err = CRYPT_OK;
    }
    *outlen = y;
 
-   return CRYPT_OK;
+   return err;
 }
 
 #endif