Multi-prime RSA support.

RSA with more than two primes is specified in
https://tools.ietf.org/html/rfc3447, although the idea goes back far
earier than that.

This change ports some of the changes in
http://rt.openssl.org/Ticket/Display.html?id=3477&user=guest&pass=guest
to BoringSSL—specifically those bits that are under an OpenSSL license.

Change-Id: I51e8e345e2148702b8ce12e00518f6ef4683d3e1
Reviewed-on: https://boringssl-review.googlesource.com/4870
Reviewed-by: Adam Langley <agl@google.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/tool/args.cc b/tool/args.cc
index a164476..850d9d8 100644
--- a/tool/args.cc
+++ b/tool/args.cc
@@ -15,6 +15,7 @@
 #include <string>
 #include <vector>
 
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -75,3 +76,28 @@ void PrintUsage(const struct argument *templates) {
     fprintf(stderr, "%s\t%s\n", templ->name, templ->description);
   }
 }
+
+bool GetUnsigned(unsigned *out, const std::string &arg_name,
+                 unsigned default_value,
+                 const std::map<std::string, std::string> &args) {
+  const auto &it = args.find(arg_name);
+  if (it == args.end()) {
+    *out = default_value;
+    return true;
+  }
+
+  const std::string &value = it->second;
+  if (value.empty()) {
+    return false;
+  }
+
+  char *endptr;
+  unsigned long int num = strtoul(value.c_str(), &endptr, 10);
+  if (*endptr ||
+      num > UINT_MAX) {
+    return false;
+  }
+
+  *out = num;
+  return true;
+}