Move x509_name_cmp() from x509_crt.c to x509.c
This is to prepare a subsequent rewrite of `x509_name_cmp()` in terms
of the X.509 name traversal helper `x509_set_sequence_iterate()`
from `x509.c`.
diff --git a/library/x509.c b/library/x509.c
index 58cd871..fd92747 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -484,6 +484,105 @@
return( 0 );
}
+/*
+ * Like memcmp, but case-insensitive and always returns -1 if different
+ */
+int mbedtls_x509_memcasecmp( const void *s1, const void *s2, size_t len )
+{
+ size_t i;
+ unsigned char diff;
+ const unsigned char *n1 = s1, *n2 = s2;
+
+ for( i = 0; i < len; i++ )
+ {
+ diff = n1[i] ^ n2[i];
+
+ if( diff == 0 )
+ continue;
+
+ if( diff == 32 &&
+ ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
+ ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
+ {
+ continue;
+ }
+
+ return( -1 );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Compare two X.509 strings, case-insensitive, and allowing for some encoding
+ * variations (but not all).
+ *
+ * Return 0 if equal, -1 otherwise.
+ */
+static int x509_string_cmp( const mbedtls_x509_buf *a,
+ const mbedtls_x509_buf *b )
+{
+ if( a->tag == b->tag &&
+ a->len == b->len &&
+ memcmp( a->p, b->p, b->len ) == 0 )
+ {
+ return( 0 );
+ }
+
+ if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
+ ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
+ a->len == b->len &&
+ mbedtls_x509_memcasecmp( a->p, b->p, b->len ) == 0 )
+ {
+ return( 0 );
+ }
+
+ return( -1 );
+}
+
+/*
+ * Compare two X.509 Names (aka rdnSequence).
+ *
+ * See RFC 5280 section 7.1, though we don't implement the whole algorithm:
+ * we sometimes return unequal when the full algorithm would return equal,
+ * but never the other way. (In particular, we don't do Unicode normalisation
+ * or space folding.)
+ *
+ * Return 0 if equal, -1 otherwise.
+ */
+int mbedtls_x509_name_cmp( const mbedtls_x509_name *a,
+ const mbedtls_x509_name *b )
+{
+ /* Avoid recursion, it might not be optimised by the compiler */
+ while( a != NULL || b != NULL )
+ {
+ if( a == NULL || b == NULL )
+ return( -1 );
+
+ /* type */
+ if( a->oid.tag != b->oid.tag ||
+ a->oid.len != b->oid.len ||
+ memcmp( a->oid.p, b->oid.p, b->oid.len ) != 0 )
+ {
+ return( -1 );
+ }
+
+ /* value */
+ if( x509_string_cmp( &a->val, &b->val ) != 0 )
+ return( -1 );
+
+ /* structure of the list of sets */
+ if( a->next_merged != b->next_merged )
+ return( -1 );
+
+ a = a->next;
+ b = b->next;
+ }
+
+ /* a == NULL == b */
+ return( 0 );
+}
+
static int x509_parse_int( unsigned char **p, size_t n, int *res )
{
*res = 0;