1 files changed, 119 insertions, 0 deletions
diff --git a/src/lib/crypto/mpi.cpp b/src/lib/crypto/mpi.cpp
new file mode 100644
index 0000000..4df7eea
--- /dev/null
+++ b/src/lib/crypto/mpi.cpp
@@ -0,0 +1,119 @@
+/*-
+ * Copyright (c) 2018 Ribose Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include "mpi.h"
+#include "mem.h"
+#include "utils.h"
+
+size_t
+mpi_bits(const pgp_mpi_t *val)
+{
+    size_t  bits = 0;
+    size_t  idx = 0;
+    uint8_t bt;
+
+    for (idx = 0; (idx < val->len) && !val->mpi[idx]; idx++)
+        ;
+
+    if (idx < val->len) {
+        for (bits = (val->len - idx - 1) << 3, bt = val->mpi[idx]; bt; bits++, bt = bt >> 1)
+            ;
+    }
+
+    return bits;
+}
+
+size_t
+mpi_bytes(const pgp_mpi_t *val)
+{
+    return val->len;
+}
+
+bool
+mem2mpi(pgp_mpi_t *val, const void *mem, size_t len)
+{
+    if (len > sizeof(val->mpi)) {
+        return false;
+    }
+
+    memcpy(val->mpi, mem, len);
+    val->len = len;
+    return true;
+}
+
+void
+mpi2mem(const pgp_mpi_t *val, void *mem)
+{
+    memcpy(mem, val->mpi, val->len);
+}
+
+char *
+mpi2hex(const pgp_mpi_t *val)
+{
+    static const char *hexes = "0123456789abcdef";
+    char *             out;
+    size_t             len;
+    size_t             idx = 0;
+
+    len = mpi_bytes(val);
+    out = (char *) malloc(len * 2 + 1);
+
+    if (!out) {
+        return out;
+    }
+
+    for (size_t i = 0; i < len; i++) {
+        out[idx++] = hexes[val->mpi[i] >> 4];
+        out[idx++] = hexes[val->mpi[i] & 0xf];
+    }
+    out[idx] = '\0';
+    return out;
+}
+
+bool
+mpi_equal(const pgp_mpi_t *val1, const pgp_mpi_t *val2)
+{
+    size_t idx1 = 0;
+    size_t idx2 = 0;
+
+    for (idx1 = 0; (idx1 < val1->len) && !val1->mpi[idx1]; idx1++)
+        ;
+
+    for (idx2 = 0; (idx2 < val2->len) && !val2->mpi[idx2]; idx2++)
+        ;
+
+    return ((val1->len - idx1) == (val2->len - idx2) &&
+            !memcmp(val1->mpi + idx1, val2->mpi + idx2, val1->len - idx1));
+}
+
+void
+mpi_forget(pgp_mpi_t *val)
+{
+    secure_clear(val, sizeof(*val));
+    val->len = 0;
+}