upstream commit

Refuse RSA keys <1024 bits in length. Improve reporting
for keys that do not meet this requirement. ok markus@

Upstream-ID: b385e2a7b13b1484792ee681daaf79e1e203df6c

1 files changed, 16 insertions, 8 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 51c24bc55..7886582d7 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.302 2017/04/30 23:18:44 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.303 2017/05/07 23:15:59 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -226,13 +226,21 @@ type_bits_valid(int type, const char *name, u_int32_t *bitsp)
             OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
         if (*bitsp > maxbits)
                 fatal("key bits exceeds maximum %d", maxbits);
-        if (type == KEY_DSA && *bitsp != 1024)
-                fatal("DSA keys must be 1024 bits");
-        else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 1024)
-                fatal("Key must at least be 1024 bits");
-        else if (type == KEY_ECDSA && sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
-                fatal("Invalid ECDSA key length - valid lengths are "
-                    "256, 384 or 521 bits");
+        switch (type) {
+        case KEY_DSA:
+                if (*bitsp != 1024)
+                        fatal("Invalid DSA key length: must be 1024 bits");
+                break;
+        case KEY_RSA:
+                if (*bitsp < SSH_RSA_MINIMUM_MODULUS_SIZE)
+                        fatal("Invalid RSA key length: minimum is %d bits",
+                            SSH_RSA_MINIMUM_MODULUS_SIZE);
+                break;
+        case KEY_ECDSA:
+                if (sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
+                        fatal("Invalid ECDSA key length: valid lengths are "
+                            "256, 384 or 521 bits");
+        }
 #endif
 }