From 1c2fabcdb34e436286b4a8760cfbfbff11ea551a Mon Sep 17 00:00:00 2001
From: Eneas U de Queiroz <cote2004-github@yahoo.com>
Date: Sat, 3 Nov 2018 15:41:10 -0300
Subject: eng_devcrypto: add configuration options

USE_SOFTDRIVERS: whether to use software (not accelerated) drivers
CIPHERS: list of ciphers to enable
DIGESTS: list of digests to enable

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7585)

diff --git a/crypto/engine/eng_devcrypto.c b/crypto/engine/eng_devcrypto.c
index a2c9a966f7..5ec38ca8f3 100644
--- a/crypto/engine/eng_devcrypto.c
+++ b/crypto/engine/eng_devcrypto.c
@@ -16,6 +16,7 @@
 #include <unistd.h>
 #include <assert.h>
 
+#include <openssl/conf.h>
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include <openssl/engine.h>
@@ -36,6 +37,30 @@
  * saner...  why re-open /dev/crypto for every session?
  */
 static int cfd;
+#define DEVCRYPTO_REQUIRE_ACCELERATED 0 /* require confirmation of acceleration */
+#define DEVCRYPTO_USE_SOFTWARE        1 /* allow software drivers */
+#define DEVCRYPTO_REJECT_SOFTWARE     2 /* only disallow confirmed software drivers */
+
+#define DEVCRYPTO_DEFAULT_USE_SOFDTRIVERS DEVCRYPTO_REJECT_SOFTWARE
+static int use_softdrivers = DEVCRYPTO_DEFAULT_USE_SOFDTRIVERS;
+
+/*
+ * cipher/digest status & acceleration definitions
+ * Make sure the defaults are set to 0
+ */
+struct driver_info_st {
+    enum devcrypto_status_t {
+        DEVCRYPTO_STATUS_UNUSABLE       = -1, /* session open failed */
+        DEVCRYPTO_STATUS_UNKNOWN        =  0, /* not tested yet */
+        DEVCRYPTO_STATUS_USABLE         =  1  /* algo can be used */
+    } status;
+
+    enum devcrypto_accelerated_t {
+        DEVCRYPTO_NOT_ACCELERATED       = -1, /* software implemented */
+        DEVCRYPTO_ACCELERATION_UNKNOWN  =  0, /* acceleration support unkown */
+        DEVCRYPTO_ACCELERATED           =  1  /* hardware accelerated */
+    } accelerated;
+};
 
 static int clean_devcrypto_session(struct session_op *sess) {
     if (ioctl(cfd, CIOCFSESSION, &sess->ses) < 0) {
@@ -119,13 +144,22 @@ static const struct cipher_data_st {
 #endif
 };
 
-static size_t get_cipher_data_index(int nid)
+static size_t find_cipher_data_index(int nid)
 {
     size_t i;
 
     for (i = 0; i < OSSL_NELEM(cipher_data); i++)
         if (nid == cipher_data[i].nid)
             return i;
+    return (size_t)-1;
+}
+
+static size_t get_cipher_data_index(int nid)
+{
+    size_t i = find_cipher_data_index(nid);
+
+    if (i != (size_t)-1)
+        return i;
 
     /*
      * Code further down must make sure that only NIDs in the table above
@@ -333,19 +367,40 @@ static int cipher_cleanup(EVP_CIPHER_CTX *ctx)
 }
 
 /*
- * Keep a table of known nids and associated methods.
+ * Keep tables of known nids, associated methods, selected ciphers, and driver
+ * info.
  * Note that known_cipher_nids[] isn't necessarily indexed the same way as
- * cipher_data[] above, which known_cipher_methods[] is.
+ * cipher_data[] above, which the other tables are.
  */
 static int known_cipher_nids[OSSL_NELEM(cipher_data)];
 static int known_cipher_nids_amount = -1; /* -1 indicates not yet initialised */
 static EVP_CIPHER *known_cipher_methods[OSSL_NELEM(cipher_data)] = { NULL, };
+static int selected_ciphers[OSSL_NELEM(cipher_data)];
+static struct driver_info_st cipher_driver_info[OSSL_NELEM(cipher_data)];
+
+
+static int devcrypto_test_cipher(size_t cipher_data_index)
+{
+    return (cipher_driver_info[cipher_data_index].status == DEVCRYPTO_STATUS_USABLE
+            && selected_ciphers[cipher_data_index] == 1
+            && (cipher_driver_info[cipher_data_index].accelerated
+                    == DEVCRYPTO_ACCELERATED
+                || use_softdrivers == DEVCRYPTO_USE_SOFTWARE
+                || (cipher_driver_info[cipher_data_index].accelerated
+                        != DEVCRYPTO_NOT_ACCELERATED
+                    && use_softdrivers == DEVCRYPTO_REJECT_SOFTWARE)));
+}
 
 static void prepare_cipher_methods(void)
 {
     size_t i;
     struct session_op sess;
     unsigned long cipher_mode;
+#ifdef CIOCGSESSINFO
+    struct session_info_op siop;
+#endif
+
+    memset(&cipher_driver_info, 0, sizeof(cipher_driver_info));
 
     memset(&sess, 0, sizeof(sess));
     sess.key = (void *)"01234567890123456789012345678901234567890123456789";
@@ -353,15 +408,16 @@ static void prepare_cipher_methods(void)
     for (i = 0, known_cipher_nids_amount = 0;
          i < OSSL_NELEM(cipher_data); i++) {
 
+        selected_ciphers[i] = 1;
         /*
-         * Check that the algo is really availably by trying to open and close
-         * a session.
+         * Check that the cipher is usable
          */
         sess.cipher = cipher_data[i].devcryptoid;
         sess.keylen = cipher_data[i].keylen;
-        if (ioctl(cfd, CIOCGSESSION, &sess) < 0
-            || ioctl(cfd, CIOCFSESSION, &sess.ses) < 0)
+        if (ioctl(cfd, CIOCGSESSION, &sess) < 0) {
+            cipher_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
             continue;
+        }
 
         cipher_mode = cipher_data[i].flags & EVP_CIPH_MODE;
 
@@ -387,15 +443,41 @@ static void prepare_cipher_methods(void)
                                             cipher_cleanup)
             || !EVP_CIPHER_meth_set_impl_ctx_size(known_cipher_methods[i],
                                                   sizeof(struct cipher_ctx))) {
+            cipher_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
             EVP_CIPHER_meth_free(known_cipher_methods[i]);
             known_cipher_methods[i] = NULL;
         } else {
+            cipher_driver_info[i].status = DEVCRYPTO_STATUS_USABLE;
+#ifdef CIOCGSESSINFO
+            siop.ses = sess.ses;
+            if (ioctl(cfd, CIOCGSESSINFO, &siop) < 0)
+                cipher_driver_info[i].accelerated = DEVCRYPTO_ACCELERATION_UNKNOWN;
+            else if (!(siop.flags & SIOP_FLAG_KERNEL_DRIVER_ONLY))
+                cipher_driver_info[i].accelerated = DEVCRYPTO_NOT_ACCELERATED;
+            else
+                cipher_driver_info[i].accelerated = DEVCRYPTO_ACCELERATED;
+#endif /* CIOCGSESSINFO */
+        }
+        ioctl(cfd, CIOCFSESSION, &sess.ses);
+        if (devcrypto_test_cipher(i)) {
             known_cipher_nids[known_cipher_nids_amount++] =
                 cipher_data[i].nid;
         }
     }
 }
 
+static void rebuild_known_cipher_nids(ENGINE *e)
+{
+    size_t i;
+
+    for (i = 0, known_cipher_nids_amount = 0; i < OSSL_NELEM(cipher_data); i++) {
+        if (devcrypto_test_cipher(i))
+            known_cipher_nids[known_cipher_nids_amount++] = cipher_data[i].nid;
+    }
+    ENGINE_unregister_ciphers(e);
+    ENGINE_register_ciphers(e);
+}
+
 static const EVP_CIPHER *get_cipher_method(int nid)
 {
     size_t i = get_cipher_data_index(nid);
@@ -438,6 +520,36 @@ static int devcrypto_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
     return *cipher != NULL;
 }
 
+static void devcrypto_select_all_ciphers(int *cipher_list)
+{
+    size_t i;
+
+    for (i = 0; i < OSSL_NELEM(cipher_data); i++)
+        cipher_list[i] = 1;
+}
+
+static int cryptodev_select_cipher_cb(const char *str, int len, void *usr)
+{
+    int *cipher_list = (int *)usr;
+    char *name;
+    const EVP_CIPHER *EVP;
+    size_t i;
+
+    if (len == 0)
+        return 1;
+    if (usr == NULL || (name = OPENSSL_strndup(str, len)) == NULL)
+        return 0;
+    EVP = EVP_get_cipherbyname(name);
+    if (EVP == NULL)
+        fprintf(stderr, "devcrypto: unknown cipher %s\n", name);
+    else if ((i = find_cipher_data_index(EVP_CIPHER_nid(EVP))) != (size_t)-1)
+        cipher_list[i] = 1;
+    else
+        fprintf(stderr, "devcrypto: cipher %s not available\n", name);
+    OPENSSL_free(name);
+    return 1;
+}
+
 /*
  * We only support digests if the cryptodev implementation supports multiple
  * data updates and session copying.  Otherwise, we would be forced to maintain
@@ -493,13 +605,22 @@ static const struct digest_data_st {
 #endif
 };
 
-static size_t get_digest_data_index(int nid)
+static size_t find_digest_data_index(int nid)
 {
     size_t i;
 
     for (i = 0; i < OSSL_NELEM(digest_data); i++)
         if (nid == digest_data[i].nid)
             return i;
+    return (size_t)-1;
+}
+
+static size_t get_digest_data_index(int nid)
+{
+    size_t i = find_digest_data_index(nid);
+
+    if (i != (size_t)-1)
+        return i;
 
     /*
      * Code further down must make sure that only NIDs in the table above
@@ -516,8 +637,8 @@ static const struct digest_data_st *get_digest_data(int nid)
 }
 
 /*
- * Following are the four necessary functions to map OpenSSL functionality
- * with cryptodev.
+ * Following are the five necessary functions to map OpenSSL functionality
+ * with cryptodev: init, update, final, cleanup, and copy.
  */
 
 static int digest_init(EVP_MD_CTX *ctx)
@@ -630,52 +751,94 @@ static int digest_cleanup(EVP_MD_CTX *ctx)
     return clean_devcrypto_session(&digest_ctx->sess);
 }
 
-static int devcrypto_test_digest(size_t digest_data_index)
-{
-    struct session_op sess1, sess2;
-    struct cphash_op cphash;
-    int ret=0;
-
-    memset(&sess1, 0, sizeof(sess1));
-    memset(&sess2, 0, sizeof(sess2));
-    sess1.mac = digest_data[digest_data_index].devcryptoid;
-    if (ioctl(cfd, CIOCGSESSION, &sess1) < 0)
-        return 0;
-    /* Make sure the driver is capable of hash state copy */
-    sess2.mac = sess1.mac;
-    if (ioctl(cfd, CIOCGSESSION, &sess2) >= 0) {
-        cphash.src_ses = sess1.ses;
-        cphash.dst_ses = sess2.ses;
-        if (ioctl(cfd, CIOCCPHASH, &cphash) >= 0)
-            ret = 1;
-        ioctl(cfd, CIOCFSESSION, &sess2.ses);
-    }
-    ioctl(cfd, CIOCFSESSION, &sess1.ses);
-    return ret;
-}
-
 /*
- * Keep a table of known nids and associated methods.
+ * Keep tables of known nids, associated methods, selected digests, and
+ * driver info.
  * Note that known_digest_nids[] isn't necessarily indexed the same way as
- * digest_data[] above, which known_digest_methods[] is.
+ * digest_data[] above, which the other tables are.
  */
 static int known_digest_nids[OSSL_NELEM(digest_data)];
 static int known_digest_nids_amount = -1; /* -1 indicates not yet initialised */
 static EVP_MD *known_digest_methods[OSSL_NELEM(digest_data)] = { NULL, };
+static int selected_digests[OSSL_NELEM(digest_data)];
+static struct driver_info_st digest_driver_info[OSSL_NELEM(digest_data)];
+
+static int devcrypto_test_digest(size_t digest_data_index)
+{
+    return (digest_driver_info[digest_data_index].status == DEVCRYPTO_STATUS_USABLE
+            && selected_digests[digest_data_index] == 1
+            && (digest_driver_info[digest_data_index].accelerated
+                    == DEVCRYPTO_ACCELERATED
+                || use_softdrivers == DEVCRYPTO_USE_SOFTWARE
+                || (digest_driver_info[digest_data_index].accelerated
+                        != DEVCRYPTO_NOT_ACCELERATED
+                    && use_softdrivers == DEVCRYPTO_REJECT_SOFTWARE)));
+}
+
+static void rebuild_known_digest_nids(ENGINE *e)
+{
+    size_t i;
+
+    for (i = 0, known_digest_nids_amount = 0; i < OSSL_NELEM(digest_data); i++) {
+        if (devcrypto_test_digest(i))
+            known_digest_nids[known_digest_nids_amount++] = digest_data[i].nid;
+    }
+    ENGINE_unregister_digests(e);
+    ENGINE_register_digests(e);
+}
 
 static void prepare_digest_methods(void)
 {
     size_t i;
+    struct session_op sess1, sess2;
+#ifdef CIOCGSESSINFO
+    struct session_info_op siop;
+#endif
+    struct cphash_op cphash;
+
+    memset(&digest_driver_info, 0, sizeof(digest_driver_info));
+
+    memset(&sess1, 0, sizeof(sess1));
+    memset(&sess2, 0, sizeof(sess2));
 
     for (i = 0, known_digest_nids_amount = 0; i < OSSL_NELEM(digest_data);
          i++) {
 
+        selected_digests[i] = 1;
+
         /*
-         * Check that the algo is usable
+         * Check that the digest is usable
          */
-        if (!devcrypto_test_digest(i))
-            continue;
+        sess1.mac = digest_data[i].devcryptoid;
+        sess2.ses = 0;
+        if (ioctl(cfd, CIOCGSESSION, &sess1) < 0) {
+            digest_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
+            goto finish;
+        }
 
+#ifdef CIOCGSESSINFO
+        /* gather hardware acceleration info from the driver */
+        siop.ses = sess1.ses;
+        if (ioctl(cfd, CIOCGSESSINFO, &siop) < 0)
+            digest_driver_info[i].accelerated = DEVCRYPTO_ACCELERATION_UNKNOWN;
+        else if (siop.flags & SIOP_FLAG_KERNEL_DRIVER_ONLY)
+            digest_driver_info[i].accelerated = DEVCRYPTO_ACCELERATED;
+        else
+            digest_driver_info[i].accelerated = DEVCRYPTO_NOT_ACCELERATED;
+#endif
+
+        /* digest must be capable of hash state copy */
+        sess2.mac = sess1.mac;
+        if (ioctl(cfd, CIOCGSESSION, &sess2) < 0) {
+            digest_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
+            goto finish;
+        }
+        cphash.src_ses = sess1.ses;
+        cphash.dst_ses = sess2.ses;
+        if (ioctl(cfd, CIOCCPHASH, &cphash) < 0) {
+            digest_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
+            goto finish;
+        }
         if ((known_digest_methods[i] = EVP_MD_meth_new(digest_data[i].nid,
                                                        NID_undef)) == NULL
             || !EVP_MD_meth_set_input_blocksize(known_digest_methods[i],
@@ -689,11 +852,18 @@ static void prepare_digest_methods(void)
             || !EVP_MD_meth_set_cleanup(known_digest_methods[i], digest_cleanup)
             || !EVP_MD_meth_set_app_datasize(known_digest_methods[i],
                                              sizeof(struct digest_ctx))) {
+            digest_driver_info[i].status = DEVCRYPTO_STATUS_UNUSABLE;
             EVP_MD_meth_free(known_digest_methods[i]);
             known_digest_methods[i] = NULL;
-        } else {
-            known_digest_nids[known_digest_nids_amount++] = digest_data[i].nid;
+            goto finish;
         }
+        digest_driver_info[i].status = DEVCRYPTO_STATUS_USABLE;
+finish:
+        ioctl(cfd, CIOCFSESSION, &sess1.ses);
+        if (sess2.ses != 0)
+            ioctl(cfd, CIOCFSESSION, &sess2.ses);
+        if (devcrypto_test_digest(i))
+            known_digest_nids[known_digest_nids_amount++] = digest_data[i].nid;
     }
 }
 
@@ -739,8 +909,154 @@ static int devcrypto_digests(ENGINE *e, const EVP_MD **digest,
     return *digest != NULL;
 }
 
+static void devcrypto_select_all_digests(int *digest_list)
+{
+    size_t i;
+
+    for (i = 0; i < OSSL_NELEM(digest_data); i++)
+        digest_list[i] = 1;
+}
+
+static int cryptodev_select_digest_cb(const char *str, int len, void *usr)
+{
+    int *digest_list = (int *)usr;
+    char *name;
+    const EVP_MD *EVP;
+    size_t i;
+
+    if (len == 0)
+        return 1;
+    if (usr == NULL || (name = OPENSSL_strndup(str, len)) == NULL)
+        return 0;
+    EVP = EVP_get_digestbyname(name);
+    if (EVP == NULL)
+        fprintf(stderr, "devcrypto: unknown digest %s\n", name);
+    else if ((i = find_digest_data_index(EVP_MD_type(EVP))) != (size_t)-1)
+        digest_list[i] = 1;
+    else
+        fprintf(stderr, "devcrypto: digest %s not available\n", name);
+    OPENSSL_free(name);
+    return 1;
+}
+
+#endif
+
+/******************************************************************************
+ *
+ * CONTROL COMMANDS
+ *
+ *****/
+
+#define DEVCRYPTO_CMD_USE_SOFTDRIVERS ENGINE_CMD_BASE
+#define DEVCRYPTO_CMD_CIPHERS (ENGINE_CMD_BASE + 1)
+#define DEVCRYPTO_CMD_DIGESTS (ENGINE_CMD_BASE + 2)
+#define DEVCRYPTO_CMD_DUMP_INFO (ENGINE_CMD_BASE + 3)
+
+/* Helper macros for CPP string composition */
+#ifndef OPENSSL_MSTR
+# define OPENSSL_MSTR_HELPER(x) #x
+# define OPENSSL_MSTR(x) OPENSSL_MSTR_HELPER(x)
+#endif
+
+static const ENGINE_CMD_DEFN devcrypto_cmds[] = {
+#ifdef CIOCGSESSINFO
+   {DEVCRYPTO_CMD_USE_SOFTDRIVERS,
+    "USE_SOFTDRIVERS",
+    "specifies whether to use software (not accelerated) drivers ("
+        OPENSSL_MSTR(DEVCRYPTO_REQUIRE_ACCELERATED) "=use only accelerated drivers, "
+        OPENSSL_MSTR(DEVCRYPTO_USE_SOFTWARE) "=allow all drivers, "
+        OPENSSL_MSTR(DEVCRYPTO_REJECT_SOFTWARE)
+        "=use if acceleration can't be determined) [default="
+        OPENSSL_MSTR(DEVCRYPTO_DEFAULT_USE_SOFDTRIVERS) "]",
+    ENGINE_CMD_FLAG_NUMERIC},
+#endif
+
+   {DEVCRYPTO_CMD_CIPHERS,
+    "CIPHERS",
+    "either ALL, NONE, or a comma-separated list of ciphers to enable [default=ALL]",
+    ENGINE_CMD_FLAG_STRING},
+
+#ifdef IMPLEMENT_DIGEST
+   {DEVCRYPTO_CMD_DIGESTS,
+    "DIGESTS",
+    "either ALL, NONE, or a comma-separated list of digests to enable [default=ALL]",
+    ENGINE_CMD_FLAG_STRING},
 #endif
 
+   {0, NULL, NULL, 0}
+};
+
+static int devcrypto_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
+{
+    int *new_list;
+    switch (cmd) {
+#ifdef CIOCGSESSINFO
+    case DEVCRYPTO_CMD_USE_SOFTDRIVERS:
+        switch (i) {
+        case DEVCRYPTO_REQUIRE_ACCELERATED:
+        case DEVCRYPTO_USE_SOFTWARE:
+        case DEVCRYPTO_REJECT_SOFTWARE:
+            break;
+        default:
+            fprintf(stderr, "devcrypto: invalid value (%ld) for USE_SOFTDRIVERS\n", i);
+            return 0;
+        }
+        if (use_softdrivers == i)
+            return 1;
+        use_softdrivers = i;
+#ifdef IMPLEMENT_DIGEST
+        rebuild_known_digest_nids(e);
+#endif
+        rebuild_known_cipher_nids(e);
+        return 1;
+#endif /* CIOCGSESSINFO */
+
+    case DEVCRYPTO_CMD_CIPHERS:
+        if (p == NULL)
+            return 1;
+        if (strcasecmp((const char *)p, "ALL") == 0) {
+            devcrypto_select_all_ciphers(selected_ciphers);
+        } else if (strcasecmp((const char*)p, "NONE") == 0) {
+            memset(selected_ciphers, 0, sizeof(selected_ciphers));
+        } else {
+            new_list=OPENSSL_zalloc(sizeof(selected_ciphers));
+            if (!CONF_parse_list(p, ',', 1, cryptodev_select_cipher_cb, new_list)) {
+                OPENSSL_free(new_list);
+                return 0;
+            }
+            memcpy(selected_ciphers, new_list, sizeof(selected_ciphers));
+            OPENSSL_free(new_list);
+        }
+        rebuild_known_cipher_nids(e);
+        return 1;
+
+#ifdef IMPLEMENT_DIGEST
+    case DEVCRYPTO_CMD_DIGESTS:
+        if (p == NULL)
+            return 1;
+        if (strcasecmp((const char *)p, "ALL") == 0) {
+            devcrypto_select_all_digests(selected_digests);
+        } else if (strcasecmp((const char*)p, "NONE") == 0) {
+            memset(selected_digests, 0, sizeof(selected_digests));
+        } else {
+            new_list=OPENSSL_zalloc(sizeof(selected_digests));
+            if (!CONF_parse_list(p, ',', 1, cryptodev_select_digest_cb, new_list)) {
+                OPENSSL_free(new_list);
+                return 0;
+            }
+            memcpy(selected_digests, new_list, sizeof(selected_digests));
+            OPENSSL_free(new_list);
+        }
+        rebuild_known_digest_nids(e);
+        return 1;
+#endif /* IMPLEMENT_DIGEST */
+
+    default:
+        break;
+    }
+    return 0;
+}
+
 /******************************************************************************
  *
  * LOAD / UNLOAD
@@ -793,6 +1109,8 @@ void engine_load_devcrypto_int()
 
     if (!ENGINE_set_id(e, "devcrypto")
         || !ENGINE_set_name(e, "/dev/crypto engine")
+        || !ENGINE_set_cmd_defns(e, devcrypto_cmds)
+        || !ENGINE_set_ctrl_function(e, devcrypto_ctrl)
 
 /*
  * Asymmetric ciphers aren't well supported with /dev/crypto.  Among the BSD
