Prohibit creating a DL_Group smaller than 1024 bits

2 files changed, 5 insertions, 3 deletions

diff --git a/doc/news.rst b/doc/news.rst
index cae2270bd..99ff04238 100644
--- a/doc/news.rst
+++ b/doc/news.rst
@@ -12,7 +12,9 @@ Version 1.11.22, Not Yet Released
 * The blinding code used for RSA, Diffie-Hellman, ElGamal and Rabin-Williams now
   periodically reinitializes the sequence of blinding values instead of always
   deriving the next value by squaring the previous ones. The reinitializion
-  interval can be controlled by 
+  interval can be controlled by the build.h parameter BOTAN_BLINDING_REINIT_INTERVAL.
+
+* DL_Group now prohibits creating a group smaller than 1024 bits.
 
 * Add System_RNG type. Previously the global system RNG was only accessible via
   `system_rng` which returned a reference to the object. However is at times
diff --git a/src/lib/pubkey/dl_group/dl_group.cpp b/src/lib/pubkey/dl_group/dl_group.cpp
index c519dcb99..fbaa67eaa 100644
--- a/src/lib/pubkey/dl_group/dl_group.cpp
+++ b/src/lib/pubkey/dl_group/dl_group.cpp
@@ -1,6 +1,6 @@
 /*
 * Discrete Logarithm Parameters
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2008,2015 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -42,7 +42,7 @@ DL_Group::DL_Group(const std::string& name)
 DL_Group::DL_Group(RandomNumberGenerator& rng,
                    PrimeType type, size_t pbits, size_t qbits)
    {
-   if(pbits < 512)
+   if(pbits < 1024)
       throw Invalid_Argument("DL_Group: prime size " + std::to_string(pbits) +
                              " is too small");