1 files changed, 141 insertions, 26 deletions

diff --git a/ssh-pkcs11-client.c b/ssh-pkcs11-client.c
index d1241ce67..e7860de89 100644
--- a/ssh-pkcs11-client.c
+++ b/ssh-pkcs11-client.c
@@ -1,6 +1,7 @@
-/* $OpenBSD: ssh-pkcs11-client.c,v 1.10 2018/07/09 21:59:10 markus Exp $ */
+/* $OpenBSD: ssh-pkcs11-client.c,v 1.15 2019/01/21 12:53:35 djm Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
+ * Copyright (c) 2014 Pedro Martelletto. All rights reserved.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -30,6 +31,7 @@
 #include <unistd.h>
 #include <errno.h>
 
+#include <openssl/ecdsa.h>
 #include <openssl/rsa.h>
 
 #include "openbsd-compat/openssl-compat.h"
@@ -47,8 +49,8 @@
 
 /* borrows code from sftp-server and ssh-agent */
 
-int fd = -1;
-pid_t pid = -1;
+static int fd = -1;
+static pid_t pid = -1;
 
 static void
 send_msg(struct sshbuf *m)
@@ -113,22 +115,27 @@ pkcs11_terminate(void)
 }
 
 static int
-pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
-    int padding)
+rsa_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa, int padding)
 {
-        struct sshkey key;      /* XXX */
-        u_char *blob, *signature = NULL;
+        struct sshkey *key = NULL;
+        struct sshbuf *msg = NULL;
+        u_char *blob = NULL, *signature = NULL;
         size_t blen, slen = 0;
         int r, ret = -1;
-        struct sshbuf *msg;
 
         if (padding != RSA_PKCS1_PADDING)
-                return (-1);
-        key.type = KEY_RSA;
-        key.rsa = rsa;
-        if ((r = sshkey_to_blob(&key, &blob, &blen)) != 0) {
+                goto fail;
+        key = sshkey_new(KEY_UNSPEC);
+        if (key == NULL) {
+                error("%s: sshkey_new failed", __func__);
+                goto fail;
+        }
+        key->type = KEY_RSA;
+        RSA_up_ref(rsa);
+        key->rsa = rsa;
+        if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) {
                 error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
-                return -1;
+                goto fail;
         }
         if ((msg = sshbuf_new()) == NULL)
                 fatal("%s: sshbuf_new failed", __func__);
@@ -137,7 +144,6 @@ pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
             (r = sshbuf_put_string(msg, from, flen)) != 0 ||
             (r = sshbuf_put_u32(msg, 0)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
-        free(blob);
         send_msg(msg);
         sshbuf_reset(msg);
 
@@ -150,22 +156,115 @@ pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
                 }
                 free(signature);
         }
+ fail:
+        free(blob);
+        sshkey_free(key);
+        sshbuf_free(msg);
+        return (ret);
+}
+
+#ifdef HAVE_EC_KEY_METHOD_NEW
+static ECDSA_SIG *
+ecdsa_do_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv,
+    const BIGNUM *rp, EC_KEY *ec)
+{
+        struct sshkey *key = NULL;
+        struct sshbuf *msg = NULL;
+        ECDSA_SIG *ret = NULL;
+        const u_char *cp;
+        u_char *blob = NULL, *signature = NULL;
+        size_t blen, slen = 0;
+        int r, nid;
+
+        nid = sshkey_ecdsa_key_to_nid(ec);
+        if (nid < 0) {
+                error("%s: couldn't get curve nid", __func__);
+                goto fail;
+        }
+
+        key = sshkey_new(KEY_UNSPEC);
+        if (key == NULL) {
+                error("%s: sshkey_new failed", __func__);
+                goto fail;
+        }
+        key->ecdsa = ec;
+        key->ecdsa_nid = nid;
+        key->type = KEY_ECDSA;
+        EC_KEY_up_ref(ec);
+
+        if ((r = sshkey_to_blob(key, &blob, &blen)) != 0) {
+                error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
+                goto fail;
+        }
+        if ((msg = sshbuf_new()) == NULL)
+                fatal("%s: sshbuf_new failed", __func__);
+        if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
+            (r = sshbuf_put_string(msg, blob, blen)) != 0 ||
+            (r = sshbuf_put_string(msg, dgst, dgst_len)) != 0 ||
+            (r = sshbuf_put_u32(msg, 0)) != 0)
+                fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        send_msg(msg);
+        sshbuf_reset(msg);
+
+        if (recv_msg(msg) == SSH2_AGENT_SIGN_RESPONSE) {
+                if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0)
+                        fatal("%s: buffer error: %s", __func__, ssh_err(r));
+                cp = signature;
+                ret = d2i_ECDSA_SIG(NULL, &cp, slen);
+                free(signature);
+        }
+
+ fail:
+        free(blob);
+        sshkey_free(key);
         sshbuf_free(msg);
         return (ret);
 }
+#endif /* HAVE_EC_KEY_METHOD_NEW */
+
+static RSA_METHOD       *helper_rsa;
+#ifdef HAVE_EC_KEY_METHOD_NEW
+static EC_KEY_METHOD    *helper_ecdsa;
+#endif /* HAVE_EC_KEY_METHOD_NEW */
+
+/* redirect private key crypto operations to the ssh-pkcs11-helper */
+static void
+wrap_key(struct sshkey *k)
+{
+        if (k->type == KEY_RSA)
+                RSA_set_method(k->rsa, helper_rsa);
+#ifdef HAVE_EC_KEY_METHOD_NEW
+        else if (k->type == KEY_ECDSA)
+                EC_KEY_set_method(k->ecdsa, helper_ecdsa);
+#endif /* HAVE_EC_KEY_METHOD_NEW */
+        else
+                fatal("%s: unknown key type", __func__);
+}
 
-/* redirect the private key encrypt operation to the ssh-pkcs11-helper */
 static int
-wrap_key(RSA *rsa)
+pkcs11_start_helper_methods(void)
 {
-        static RSA_METHOD *helper_rsa;
+        if (helper_rsa != NULL)
+                return (0);
+
+#ifdef HAVE_EC_KEY_METHOD_NEW
+        int (*orig_sign)(int, const unsigned char *, int, unsigned char *,
+            unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL;
+        if (helper_ecdsa != NULL)
+                return (0);
+        helper_ecdsa = EC_KEY_METHOD_new(EC_KEY_OpenSSL());
+        if (helper_ecdsa == NULL)
+                return (-1);
+        EC_KEY_METHOD_get_sign(helper_ecdsa, &orig_sign, NULL, NULL);
+        EC_KEY_METHOD_set_sign(helper_ecdsa, orig_sign, NULL, ecdsa_do_sign);
+#endif /* HAVE_EC_KEY_METHOD_NEW */
 
         if ((helper_rsa = RSA_meth_dup(RSA_get_default_method())) == NULL)
                 fatal("%s: RSA_meth_dup failed", __func__);
         if (!RSA_meth_set1_name(helper_rsa, "ssh-pkcs11-helper") ||
-            !RSA_meth_set_priv_enc(helper_rsa, pkcs11_rsa_private_encrypt))
+            !RSA_meth_set_priv_enc(helper_rsa, rsa_encrypt))
                 fatal("%s: failed to prepare method", __func__);
-        RSA_set_method(rsa, helper_rsa);
+
         return (0);
 }
 
@@ -173,6 +272,15 @@ static int
 pkcs11_start_helper(void)
 {
         int pair[2];
+        char *helper, *verbosity = NULL;
+
+        if (log_level_get() >= SYSLOG_LEVEL_DEBUG1)
+                verbosity = "-vvv";
+
+        if (pkcs11_start_helper_methods() == -1) {
+                error("pkcs11_start_helper_methods failed");
+                return (-1);
+        }
 
         if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
                 error("socketpair: %s", strerror(errno));
@@ -189,10 +297,13 @@ pkcs11_start_helper(void)
                 }
                 close(pair[0]);
                 close(pair[1]);
-                execlp(_PATH_SSH_PKCS11_HELPER, _PATH_SSH_PKCS11_HELPER,
-                    (char *)NULL);
-                fprintf(stderr, "exec: %s: %s\n", _PATH_SSH_PKCS11_HELPER,
-                    strerror(errno));
+                helper = getenv("SSH_PKCS11_HELPER");
+                if (helper == NULL || strlen(helper) == 0)
+                        helper = _PATH_SSH_PKCS11_HELPER;
+                debug("%s: starting %s %s", __func__, helper,
+                    verbosity == NULL ? "" : verbosity);
+                execlp(helper, helper, verbosity, (char *)NULL);
+                fprintf(stderr, "exec: %s: %s\n", helper, strerror(errno));
                 _exit(1);
         }
         close(pair[1]);
@@ -204,7 +315,7 @@ int
 pkcs11_add_provider(char *name, char *pin, struct sshkey ***keysp)
 {
         struct sshkey *k;
-        int r;
+        int r, type;
         u_char *blob;
         size_t blen;
         u_int nkeys, i;
@@ -222,7 +333,8 @@ pkcs11_add_provider(char *name, char *pin, struct sshkey ***keysp)
         send_msg(msg);
         sshbuf_reset(msg);
 
-        if (recv_msg(msg) == SSH2_AGENT_IDENTITIES_ANSWER) {
+        type = recv_msg(msg);
+        if (type == SSH2_AGENT_IDENTITIES_ANSWER) {
                 if ((r = sshbuf_get_u32(msg, &nkeys)) != 0)
                         fatal("%s: buffer error: %s", __func__, ssh_err(r));
                 *keysp = xcalloc(nkeys, sizeof(struct sshkey *));
@@ -234,10 +346,13 @@ pkcs11_add_provider(char *name, char *pin, struct sshkey ***keysp)
                                     __func__, ssh_err(r));
                         if ((r = sshkey_from_blob(blob, blen, &k)) != 0)
                                 fatal("%s: bad key: %s", __func__, ssh_err(r));
-                        wrap_key(k->rsa);
+                        wrap_key(k);
                         (*keysp)[i] = k;
                         free(blob);
                 }
+        } else if (type == SSH2_AGENT_FAILURE) {
+                if ((r = sshbuf_get_u32(msg, &nkeys)) != 0)
+                        nkeys = -1;
         } else {
                 nkeys = -1;
         }