1 files changed, 41 insertions, 4 deletions

diff --git a/ssh-rsa.c b/ssh-rsa.c
index cde05df10..f570ae6d4 100644
--- a/ssh-rsa.c
+++ b/ssh-rsa.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-rsa.c,v 1.60 2016/09/12 23:39:34 djm Exp $ */
+/* $OpenBSD: ssh-rsa.c,v 1.62 2017/07/01 13:50:45 djm Exp $ */
 /*
  * Copyright (c) 2000, 2003 Markus Friedl <markus@openbsd.org>
  *
@@ -78,6 +78,41 @@ rsa_hash_alg_nid(int type)
         }
 }
 
+/* calculate p-1 and q-1 */
+int
+ssh_rsa_generate_additional_parameters(struct sshkey *key)
+{
+        RSA *rsa;
+        BIGNUM *aux = NULL;
+        BN_CTX *ctx = NULL;
+        int r;
+
+        if (key == NULL || key->rsa == NULL ||
+            sshkey_type_plain(key->type) != KEY_RSA)
+                return SSH_ERR_INVALID_ARGUMENT;
+
+        if ((ctx = BN_CTX_new()) == NULL)
+                return SSH_ERR_ALLOC_FAIL;
+        if ((aux = BN_new()) == NULL) {
+                r = SSH_ERR_ALLOC_FAIL;
+                goto out;
+        }
+        rsa = key->rsa;
+
+        if ((BN_sub(aux, rsa->q, BN_value_one()) == 0) ||
+            (BN_mod(rsa->dmq1, rsa->d, aux, ctx) == 0) ||
+            (BN_sub(aux, rsa->p, BN_value_one()) == 0) ||
+            (BN_mod(rsa->dmp1, rsa->d, aux, ctx) == 0)) {
+                r = SSH_ERR_LIBCRYPTO_ERROR;
+                goto out;
+        }
+        r = 0;
+ out:
+        BN_clear_free(aux);
+        BN_CTX_free(ctx);
+        return r;
+}
+
 /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
 int
 ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
@@ -99,9 +134,10 @@ ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
         else
                 hash_alg = rsa_hash_alg_from_ident(alg_ident);
         if (key == NULL || key->rsa == NULL || hash_alg == -1 ||
-            sshkey_type_plain(key->type) != KEY_RSA ||
-            BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+            sshkey_type_plain(key->type) != KEY_RSA)
                 return SSH_ERR_INVALID_ARGUMENT;
+        if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+                return SSH_ERR_KEY_LENGTH;
         slen = RSA_size(key->rsa);
         if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM)
                 return SSH_ERR_INVALID_ARGUMENT;
@@ -172,9 +208,10 @@ ssh_rsa_verify(const struct sshkey *key,
 
         if (key == NULL || key->rsa == NULL ||
             sshkey_type_plain(key->type) != KEY_RSA ||
-            BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE ||
             sig == NULL || siglen == 0)
                 return SSH_ERR_INVALID_ARGUMENT;
+        if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE)
+                return SSH_ERR_KEY_LENGTH;
 
         if ((b = sshbuf_from(sig, siglen)) == NULL)
                 return SSH_ERR_ALLOC_FAIL;