Parse IBAN (field 5F53) as format 'an'

EMV 4.4 Book 3 Annex A states that this field has format 'var' and a
length of up to 34 bytes while Wikipedia states that an IBAN consists of
34 alphanumeric characters. Therefore this implementation assumes that
this field can be interpreted as format 'an'.

src/emv_strings.c

@@ -452,7 +452,12 @@ int emv_tlv_get_info(
 				"Uniquely identifies the account of a customer at a financial "
 				"institution as defined in ISO 13616.";
 			info->format = EMV_FORMAT_VAR;
-			return emv_tlv_value_get_string(tlv, EMV_FORMAT_CN, 34, value_str, value_str_len);
+			// EMV 4.4 Book 3 Annex A states that this field has format 'var'
+			// and a length of up to 34 bytes while Wikipedia states that an
+			// IBAN consists of 34 alphanumeric characters. Therefore this
+			// implementation assumes that this field can be interpreted as
+			// format 'an'.
+			return emv_tlv_value_get_string(tlv, EMV_FORMAT_AN, 34, value_str, value_str_len);
 
 		case EMV_TAG_5F54_BANK_IDENTIFIER_CODE:
 			info->tag_name = "Bank Identifier Code (BIC)";