eng_devcrypto: close open session on init

cipher_init may be called on an already initialized context, without a
necessary cleanup.  This separates cleanup from initialization, closing
an eventual open session before creating a new one.

Move the /dev/crypto session cleanup code to its own function.
Signed-off-by: NEneas U de Queiroz <cote2004-github@yahoo.com>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NNicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/8306)

crypto/engine/eng_devcrypto.c

@@ -37,6 +37,15 @@
  */
 static int cfd;
 
+static int clean_devcrypto_session(struct session_op *sess) {
+    if (ioctl(cfd, CIOCFSESSION, &sess->ses) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+    memset(sess, 0, sizeof(struct session_op));
+    return 1;
+}
+
 /******************************************************************************
  *
  * Ciphers
@@ -145,7 +154,11 @@ static int cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
     const struct cipher_data_st *cipher_d =
         get_cipher_data(EVP_CIPHER_CTX_nid(ctx));
 
-    memset(&cipher_ctx->sess, 0, sizeof(cipher_ctx->sess));
+    /* cleanup a previous session */
+    if (cipher_ctx->sess.ses != 0 &&
+        clean_devcrypto_session(&cipher_ctx->sess) == 0)
+        return 0;
+
     cipher_ctx->sess.cipher = cipher_d->devcryptoid;
     cipher_ctx->sess.keylen = cipher_d->keylen;
     cipher_ctx->sess.key = (void *)key;
@@ -284,15 +297,28 @@ static int ctr_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
 
 static int cipher_ctrl(EVP_CIPHER_CTX *ctx, int type, int p1, void* p2)
 {
+    struct cipher_ctx *cipher_ctx =
+        (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
     EVP_CIPHER_CTX *to_ctx = (EVP_CIPHER_CTX *)p2;
-    struct cipher_ctx *cipher_ctx;
+    struct cipher_ctx *to_cipher_ctx;
 
-    if (type == EVP_CTRL_COPY) {
+    switch (type) {
+    case EVP_CTRL_COPY:
+        if (cipher_ctx == NULL)
+            return 1;
         /* when copying the context, a new session needs to be initialized */
-        cipher_ctx = (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
-        return (cipher_ctx == NULL)
-            || cipher_init(to_ctx, cipher_ctx->sess.key, EVP_CIPHER_CTX_iv(ctx),
+        to_cipher_ctx =
+            (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(to_ctx);
+        memset(&to_cipher_ctx->sess, 0, sizeof(to_cipher_ctx->sess));
+        return cipher_init(to_ctx, cipher_ctx->sess.key, EVP_CIPHER_CTX_iv(ctx),
                            (cipher_ctx->op == COP_ENCRYPT));
+
+    case EVP_CTRL_INIT:
+        memset(&cipher_ctx->sess, 0, sizeof(cipher_ctx->sess));
+        return 1;
+
+    default:
+        break;
     }
 
     return -1;
@@ -303,12 +329,7 @@ static int cipher_cleanup(EVP_CIPHER_CTX *ctx)
     struct cipher_ctx *cipher_ctx =
         (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
 
-    if (ioctl(cfd, CIOCFSESSION, &cipher_ctx->sess.ses) < 0) {
-        SYSerr(SYS_F_IOCTL, errno);
-        return 0;
-    }
-
-    return 1;
+    return clean_devcrypto_session(&cipher_ctx->sess);
 }
 
 /*
@@ -354,6 +375,7 @@ static void prepare_cipher_methods(void)
             || !EVP_CIPHER_meth_set_flags(known_cipher_methods[i],
                                           cipher_data[i].flags
                                           | EVP_CIPH_CUSTOM_COPY
+                                          | EVP_CIPH_CTRL_INIT
                                           | EVP_CIPH_FLAG_DEFAULT_ASN1)
             || !EVP_CIPHER_meth_set_init(known_cipher_methods[i], cipher_init)
             || !EVP_CIPHER_meth_set_do_cipher(known_cipher_methods[i],
@@ -596,11 +618,8 @@ static int digest_cleanup(EVP_MD_CTX *ctx)
 
     if (digest_ctx == NULL)
         return 1;
-    if (ioctl(cfd, CIOCFSESSION, &digest_ctx->sess.ses) < 0) {
-        SYSerr(SYS_F_IOCTL, errno);
-        return 0;
-    }
-    return 1;
+
+    return clean_devcrypto_session(&digest_ctx->sess);
 }
 
 static int devcrypto_test_digest(size_t digest_data_index)