- markus@cvs.openbsd.org 2013/11/02 20:03:54

     [ssh-pkcs11.c]
     support pkcs#11 tokes that only provide x509 zerts instead of raw pubkeys;
     fixes bz#1908; based on patch from Laurent Barbe; ok djm

1 files changed, 101 insertions, 40 deletions

diff --git a/ssh-pkcs11.c b/ssh-pkcs11.c
index 618c07526..6e8d2db36 100644
--- a/ssh-pkcs11.c
+++ b/ssh-pkcs11.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-pkcs11.c,v 1.8 2013/07/12 00:20:00 djm Exp $ */
+/* $OpenBSD: ssh-pkcs11.c,v 1.9 2013/11/02 20:03:54 markus Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
  *
@@ -31,6 +31,8 @@
 
 #include "openbsd-compat/sys-queue.h"
 
+#include <openssl/x509.h>
+
 #define CRYPTOKI_COMPAT
 #include "pkcs11.h"
 
@@ -225,24 +227,19 @@ pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
         CK_OBJECT_HANDLE        obj;
         CK_ULONG                tlen = 0;
         CK_RV                   rv;
-        CK_OBJECT_CLASS         private_key_class = CKO_PRIVATE_KEY;
+        CK_OBJECT_CLASS private_key_class = CKO_PRIVATE_KEY;
         CK_BBOOL                true_val = CK_TRUE;
         CK_MECHANISM            mech = {
                 CKM_RSA_PKCS, NULL_PTR, 0
         };
         CK_ATTRIBUTE            key_filter[] = {
-                {CKA_CLASS, NULL, sizeof(private_key_class) },
+                {CKA_CLASS, &private_key_class, sizeof(private_key_class) },
                 {CKA_ID, NULL, 0},
-                {CKA_SIGN, NULL, sizeof(true_val) }
+                {CKA_SIGN, &true_val, sizeof(true_val) }
         };
         char                    *pin, prompt[1024];
         int                     rval = -1;
 
-        /* some compilers complain about non-constant initializer so we
-           use NULL in CK_ATTRIBUTE above and set the values here */
-        key_filter[0].pValue = &private_key_class;
-        key_filter[2].pValue = &true_val;
-
         if ((k11 = RSA_get_app_data(rsa)) == NULL) {
                 error("RSA_get_app_data failed for rsa %p", rsa);
                 return (-1);
@@ -384,36 +381,73 @@ pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin)
  * add 'wrapped' public keys to the 'keysp' array and increment nkeys.
  * keysp points to an (possibly empty) array with *nkeys keys.
  */
+static int pkcs11_fetch_keys_filter(struct pkcs11_provider *, CK_ULONG,
+    CK_ATTRIBUTE [], CK_ATTRIBUTE [3], Key ***, int *)
+        __attribute__((__bounded__(__minbytes__,4, 3 * sizeof(CK_ATTRIBUTE))));
+
+static int
+pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx,
+    Key ***keysp, int *nkeys)
+{
+        CK_OBJECT_CLASS pubkey_class = CKO_PUBLIC_KEY;
+        CK_OBJECT_CLASS cert_class = CKO_CERTIFICATE;
+        CK_ATTRIBUTE            pubkey_filter[] = {
+                { CKA_CLASS, &pubkey_class, sizeof(pubkey_class) }
+        };
+        CK_ATTRIBUTE            cert_filter[] = {
+                { CKA_CLASS, &cert_class, sizeof(cert_class) }
+        };
+        CK_ATTRIBUTE            pubkey_attribs[] = {
+                { CKA_ID, NULL, 0 },
+                { CKA_MODULUS, NULL, 0 },
+                { CKA_PUBLIC_EXPONENT, NULL, 0 }
+        };
+        CK_ATTRIBUTE            cert_attribs[] = {
+                { CKA_ID, NULL, 0 },
+                { CKA_SUBJECT, NULL, 0 },
+                { CKA_VALUE, NULL, 0 }
+        };
+
+        if (pkcs11_fetch_keys_filter(p, slotidx, pubkey_filter, pubkey_attribs,
+            keysp, nkeys) < 0 ||
+            pkcs11_fetch_keys_filter(p, slotidx, cert_filter, cert_attribs,
+            keysp, nkeys) < 0)
+                return (-1);
+        return (0);
+}
+
 static int
-pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx, Key ***keysp,
-    int *nkeys)
+pkcs11_key_included(Key ***keysp, int *nkeys, Key *key)
+{
+        int i;
+
+        for (i = 0; i < *nkeys; i++)
+                if (key_equal(key, *keysp[i]))
+                        return (1);
+        return (0);
+}
+
+static int
+pkcs11_fetch_keys_filter(struct pkcs11_provider *p, CK_ULONG slotidx,
+    CK_ATTRIBUTE filter[], CK_ATTRIBUTE attribs[3],
+    Key ***keysp, int *nkeys)
 {
         Key                     *key;
         RSA                     *rsa;
+        X509                    *x509;
+        EVP_PKEY                *evp;
         int                     i;
+        const u_char            *cp;
         CK_RV                   rv;
         CK_OBJECT_HANDLE        obj;
         CK_ULONG                nfound;
         CK_SESSION_HANDLE       session;
         CK_FUNCTION_LIST        *f;
-        CK_OBJECT_CLASS         pubkey_class = CKO_PUBLIC_KEY;
-        CK_ATTRIBUTE            pubkey_filter[] = {
-                { CKA_CLASS, NULL, sizeof(pubkey_class) }
-        };
-        CK_ATTRIBUTE            attribs[] = {
-                { CKA_ID, NULL, 0 },
-                { CKA_MODULUS, NULL, 0 },
-                { CKA_PUBLIC_EXPONENT, NULL, 0 }
-        };
-
-        /* some compilers complain about non-constant initializer so we
-           use NULL in CK_ATTRIBUTE above and set the value here */
-        pubkey_filter[0].pValue = &pubkey_class;
 
         f = p->function_list;
         session = p->slotinfo[slotidx].session;
         /* setup a filter the looks for public keys */
-        if ((rv = f->C_FindObjectsInit(session, pubkey_filter, 1)) != CKR_OK) {
+        if ((rv = f->C_FindObjectsInit(session, filter, 1)) != CKR_OK) {
                 error("C_FindObjectsInit failed: %lu", rv);
                 return (-1);
         }
@@ -441,32 +475,59 @@ pkcs11_fetch_keys(struct pkcs11_provider *p, CK_ULONG slotidx, Key ***keysp,
                 /* allocate buffers for attributes */
                 for (i = 0; i < 3; i++)
                         attribs[i].pValue = xmalloc(attribs[i].ulValueLen);
-                /* retrieve ID, modulus and public exponent of RSA key */
+                /*
+                 * retrieve ID, modulus and public exponent of RSA key,
+                 * or ID, subject and value for certificates.
+                 */
+                rsa = NULL;
                 if ((rv = f->C_GetAttributeValue(session, obj, attribs, 3))
                     != CKR_OK) {
                         error("C_GetAttributeValue failed: %lu", rv);
-                } else if ((rsa = RSA_new()) == NULL) {
-                        error("RSA_new failed");
+                } else if (attribs[1].type == CKA_MODULUS ) {
+                        if ((rsa = RSA_new()) == NULL) {
+                                error("RSA_new failed");
+                        } else {
+                                rsa->n = BN_bin2bn(attribs[1].pValue,
+                                    attribs[1].ulValueLen, NULL);
+                                rsa->e = BN_bin2bn(attribs[2].pValue,
+                                    attribs[2].ulValueLen, NULL);
+                        }
                 } else {
-                        rsa->n = BN_bin2bn(attribs[1].pValue,
-                            attribs[1].ulValueLen, NULL);
-                        rsa->e = BN_bin2bn(attribs[2].pValue,
-                            attribs[2].ulValueLen, NULL);
-                        if (rsa->n && rsa->e &&
-                            pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
-                                key = key_new(KEY_UNSPEC);
-                                key->rsa = rsa;
-                                key->type = KEY_RSA;
-                                key->flags |= KEY_FLAG_EXT;
+                        cp = attribs[2].pValue;
+                        if ((x509 = X509_new()) == NULL) {
+                                error("X509_new failed");
+                        } else if (d2i_X509(&x509, &cp, attribs[2].ulValueLen)
+                            == NULL) {
+                                error("d2i_X509 failed");
+                        } else if ((evp = X509_get_pubkey(x509)) == NULL ||
+                            evp->type != EVP_PKEY_RSA ||
+                            evp->pkey.rsa == NULL) {
+                                debug("X509_get_pubkey failed or no rsa");
+                        } else if ((rsa = RSAPublicKey_dup(evp->pkey.rsa))
+                            == NULL) {
+                                error("RSAPublicKey_dup");
+                        }
+                        if (x509)
+                                X509_free(x509);
+                }
+                if (rsa && rsa->n && rsa->e &&
+                    pkcs11_rsa_wrap(p, slotidx, &attribs[0], rsa) == 0) {
+                        key = key_new(KEY_UNSPEC);
+                        key->rsa = rsa;
+                        key->type = KEY_RSA;
+                        key->flags |= KEY_FLAG_EXT;
+                        if (pkcs11_key_included(keysp, nkeys, key)) {
+                                key_free(key);
+                        } else {
                                 /* expand key array and add key */
                                 *keysp = xrealloc(*keysp, *nkeys + 1,
                                     sizeof(Key *));
                                 (*keysp)[*nkeys] = key;
                                 *nkeys = *nkeys + 1;
                                 debug("have %d keys", *nkeys);
-                        } else {
-                                RSA_free(rsa);
                         }
+                } else if (rsa) {
+                        RSA_free(rsa);
                 }
                 for (i = 0; i < 3; i++)
                         free(attribs[i].pValue);