Added support code for RSA and EC key encoding (including reconstruction of all publi...

[BearSSL] / src / x509 / asn1enc.c

diff --git a/src/x509/asn1enc.c b/src/x509/asn1enc.c
new file mode 100644 (file)
index 0000000..7a74963
--- /dev/null
+++ b/src/x509/asn1enc.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/* see inner.h */
+br_asn1_uint
+br_asn1_uint_prepare(const void *xdata, size_t xlen)
+{
+       const unsigned char *x;
+       br_asn1_uint t;
+
+       x = xdata;
+       while (xlen > 0 && *x == 0) {
+               x ++;
+               xlen --;
+       }
+       t.data = x;
+       t.len = xlen;
+       t.asn1len = xlen;
+       if (xlen == 0 || x[0] >= 0x80) {
+               t.asn1len ++;
+       }
+       return t;
+}
+
+/* see inner.h */
+size_t
+br_asn1_encode_length(void *dest, size_t len)
+{
+       unsigned char *buf;
+       size_t z;
+       int i, j;
+
+       buf = dest;
+       if (len < 0x80) {
+               if (buf != NULL) {
+                       *buf = len;
+               }
+               return 1;
+       }
+       i = 0;
+       for (z = len; z != 0; z >>= 8) {
+               i ++;
+       }
+       if (buf != NULL) {
+               *buf ++ = 0x80 + i;
+               for (j = i - 1; j >= 0; j --) {
+                       *buf ++ = len >> (j << 3);
+               }
+       }
+       return i + 1;
+}
+
+/* see inner.h */
+size_t
+br_asn1_encode_uint(void *dest, br_asn1_uint pp)
+{
+       unsigned char *buf;
+       size_t lenlen;
+
+       if (dest == NULL) {
+               return 1 + br_asn1_encode_length(NULL, pp.asn1len) + pp.asn1len;
+       }
+       buf = dest;
+       *buf ++ = 0x02;
+       lenlen = br_asn1_encode_length(buf, pp.asn1len);
+       buf += lenlen;
+       *buf = 0x00;
+       memcpy(buf + pp.asn1len - pp.len, pp.data, pp.len);
+       return 1 + lenlen + pp.asn1len;
+}