Issue warnings for large DSA and RSA keys

[openssl.git] / apps / genrsa.c

diff --git a/apps/genrsa.c b/apps/genrsa.c
index 2bc8fa08275c326b2e9fc1ac56c0a572ff4a9ba2..c17cd147154eea5c78915b0bb1ee8552d1026abd 100644 (file)
--- a/apps/genrsa.c
+++ b/apps/genrsa.c
@@ -123,6 +123,11 @@ opthelp:
     if (argc == 1) {
         if (!opt_int(argv[0], &num) || num <= 0)
             goto end;
+        if (num > OPENSSL_RSA_MAX_MODULUS_BITS)
+            BIO_printf(bio_err,
+                       "Warning: It is not recommended to use more than %d bit for RSA keys.\n"
+                       "         Your key size is %d! Larger key size may behave not as expected.\n",
+                       OPENSSL_RSA_MAX_MODULUS_BITS, num);
     } else if (argc > 0) {
         BIO_printf(bio_err, "Extra arguments given.\n");
         goto opthelp;