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

[BearSSL] / src / x509 / encode_rsa_rawder.c

diff --git a/src/x509/encode_rsa_rawder.c b/src/x509/encode_rsa_rawder.c
new file mode 100644 (file)
index 0000000..1a8052b
--- /dev/null
+++ b/src/x509/encode_rsa_rawder.c
@@ -0,0 +1,96 @@
+/*
+ * 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 bearssl_x509.h */
+size_t
+br_encode_rsa_raw_der(void *dest, const br_rsa_private_key *sk,
+       const br_rsa_public_key *pk, const void *d, size_t dlen)
+{
+       /*
+        * ASN.1 format:
+        *
+        *   RSAPrivateKey ::= SEQUENCE {
+        *       version           Version,
+        *       modulus           INTEGER,  -- n
+        *       publicExponent    INTEGER,  -- e
+        *       privateExponent   INTEGER,  -- d
+        *       prime1            INTEGER,  -- p
+        *       prime2            INTEGER,  -- q
+        *       exponent1         INTEGER,  -- d mod (p-1)
+        *       exponent2         INTEGER,  -- d mod (q-1)
+        *       coefficient       INTEGER,  -- (inverse of q) mod p
+        *       otherPrimeInfos   OtherPrimeInfos OPTIONAL
+        *   }
+        *
+        * The 'version' field is an INTEGER of value 0 (meaning: there
+        * are exactly two prime factors), and 'otherPrimeInfos' will
+        * be absent (because there are exactly two prime factors).
+        */
+
+       br_asn1_uint num[9];
+       size_t u, slen;
+
+       /*
+        * For all INTEGER values, get the pointer and length for the
+        * data bytes.
+        */
+       num[0] = br_asn1_uint_prepare(NULL, 0);
+       num[1] = br_asn1_uint_prepare(pk->n, pk->nlen);
+       num[2] = br_asn1_uint_prepare(pk->e, pk->elen);
+       num[3] = br_asn1_uint_prepare(d, dlen);
+       num[4] = br_asn1_uint_prepare(sk->p, sk->plen);
+       num[5] = br_asn1_uint_prepare(sk->q, sk->qlen);
+       num[6] = br_asn1_uint_prepare(sk->dp, sk->dplen);
+       num[7] = br_asn1_uint_prepare(sk->dq, sk->dqlen);
+       num[8] = br_asn1_uint_prepare(sk->iq, sk->iqlen);
+
+       /*
+        * Get the length of the SEQUENCE contents.
+        */
+       slen = 0;
+       for (u = 0; u < 9; u ++) {
+               uint32_t ilen;
+
+               ilen = num[u].asn1len;
+               slen += 1 + len_of_len(ilen) + ilen;
+       }
+
+       if (dest == NULL) {
+               return 1 + len_of_len(slen) + slen;
+       } else {
+               unsigned char *buf;
+               size_t lenlen;
+
+               buf = dest;
+               *buf ++ = 0x30;  /* SEQUENCE tag */
+               lenlen = br_asn1_encode_length(buf, slen);
+               buf += lenlen;
+               for (u = 0; u < 9; u ++) {
+                       buf += br_asn1_encode_uint(buf, num[u]);
+               }
+               return 1 + lenlen + slen;
+       }
+}