e_devcrypto: make the /dev/crypto engine dynamic

Engine has been moved from crypto/engine/eng_devcrypto.c to
engines/e_devcrypto.c.

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

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7859)

2 files changed, 1297 insertions, 0 deletions

diff --git a/engines/build.info b/engines/build.info
index 27f1cecf26..f94e620a02 100644
--- a/engines/build.info
+++ b/engines/build.info
@@ -10,6 +10,9 @@ IF[{- !$disabled{"engine"} -}]
     IF[{- !$disabled{afalgeng} -}]
       SOURCE[../libcrypto]=e_afalg.c
     ENDIF
+    IF[{- !$disabled{"devcryptoeng"} -}]
+      SOURCE[../libcrypto]=e_devcrypto.c
+    ENDIF
   ELSE
     MODULES{engine}=padlock
     SOURCE[padlock]=e_padlock.c {- $target{padlock_asm_src} -}
@@ -39,6 +42,16 @@ IF[{- !$disabled{"engine"} -}]
         GENERATE[afalg.ld]=../util/engines.num
       ENDIF
     ENDIF
+    IF[{- !$disabled{"devcryptoeng"} -}]
+      ENGINES=devcrypto
+      SOURCE[devcrypto]=e_devcrypto.c
+      DEPEND[devcrypto]=../libcrypto
+      INCLUDE[devcrypto]=../include
+      IF[{- defined $target{shared_defflag} -}]
+        SHARED_SOURCE[devcrypto]=devcrypto.ld
+        GENERATE[devcrypto.ld]=../util/engines.num
+      ENDIF
+    ENDIF
 
     MODULES{noinst,engine}=ossltest dasync
     SOURCE[dasync]=e_dasync.c
diff --git a/engines/e_devcrypto.c b/engines/e_devcrypto.c
new file mode 100644
index 0000000000..87e4c2437c
--- /dev/null
+++ b/engines/e_devcrypto.c
@@ -0,0 +1,1284 @@
+/*
+ * Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "../e_os.h"
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <assert.h>
+
+#include <openssl/conf.h>
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/engine.h>
+#include <openssl/objects.h>
+#include <crypto/cryptodev.h>
+
+/* #define ENGINE_DEVCRYPTO_DEBUG */
+
+#ifdef CRYPTO_ALGORITHM_MIN
+# define CHECK_BSD_STYLE_MACROS
+#endif
+
+#define engine_devcrypto_id "devcrypto"
+
+/*
+ * ONE global file descriptor for all sessions.  This allows operations
+ * such as digest session data copying (see digest_copy()), but is also
+ * saner...  why re-open /dev/crypto for every session?
+ */
+static int cfd = -1;
+#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_FAILURE         = -3, /* unusable for other reason */
+        DEVCRYPTO_STATUS_NO_CIOCCPHASH   = -2, /* hash state copy not supported */
+        DEVCRYPTO_STATUS_NO_CIOCGSESSION = -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;
+
+    char *driver_name;
+};
+
+#ifdef OPENSSL_NO_DYNAMIC_ENGINE
+void engine_load_devcrypto_int(void);
+#endif
+
+/******************************************************************************
+ *
+ * Ciphers
+ *
+ * Because they all do the same basic operation, we have only one set of
+ * method functions for them all to share, and a mapping table between
+ * NIDs and cryptodev IDs, with all the necessary size data.
+ *
+ *****/
+
+struct cipher_ctx {
+    struct session_op sess;
+    int op;                      /* COP_ENCRYPT or COP_DECRYPT */
+    unsigned long mode;          /* EVP_CIPH_*_MODE */
+
+    /* to handle ctr mode being a stream cipher */
+    unsigned char partial[EVP_MAX_BLOCK_LENGTH];
+    unsigned int blocksize, num;
+};
+
+static const struct cipher_data_st {
+    int nid;
+    int blocksize;
+    int keylen;
+    int ivlen;
+    int flags;
+    int devcryptoid;
+} cipher_data[] = {
+#ifndef OPENSSL_NO_DES
+    { NID_des_cbc, 8, 8, 8, EVP_CIPH_CBC_MODE, CRYPTO_DES_CBC },
+    { NID_des_ede3_cbc, 8, 24, 8, EVP_CIPH_CBC_MODE, CRYPTO_3DES_CBC },
+#endif
+#ifndef OPENSSL_NO_BF
+    { NID_bf_cbc, 8, 16, 8, EVP_CIPH_CBC_MODE, CRYPTO_BLF_CBC },
+#endif
+#ifndef OPENSSL_NO_CAST
+    { NID_cast5_cbc, 8, 16, 8, EVP_CIPH_CBC_MODE, CRYPTO_CAST_CBC },
+#endif
+    { NID_aes_128_cbc, 16, 128 / 8, 16, EVP_CIPH_CBC_MODE, CRYPTO_AES_CBC },
+    { NID_aes_192_cbc, 16, 192 / 8, 16, EVP_CIPH_CBC_MODE, CRYPTO_AES_CBC },
+    { NID_aes_256_cbc, 16, 256 / 8, 16, EVP_CIPH_CBC_MODE, CRYPTO_AES_CBC },
+#ifndef OPENSSL_NO_RC4
+    { NID_rc4, 1, 16, 0, EVP_CIPH_STREAM_CIPHER, CRYPTO_ARC4 },
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_AES_CTR)
+    { NID_aes_128_ctr, 16, 128 / 8, 16, EVP_CIPH_CTR_MODE, CRYPTO_AES_CTR },
+    { NID_aes_192_ctr, 16, 192 / 8, 16, EVP_CIPH_CTR_MODE, CRYPTO_AES_CTR },
+    { NID_aes_256_ctr, 16, 256 / 8, 16, EVP_CIPH_CTR_MODE, CRYPTO_AES_CTR },
+#endif
+#if 0                            /* Not yet supported */
+    { NID_aes_128_xts, 16, 128 / 8 * 2, 16, EVP_CIPH_XTS_MODE, CRYPTO_AES_XTS },
+    { NID_aes_256_xts, 16, 256 / 8 * 2, 16, EVP_CIPH_XTS_MODE, CRYPTO_AES_XTS },
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_AES_ECB)
+    { NID_aes_128_ecb, 16, 128 / 8, 0, EVP_CIPH_ECB_MODE, CRYPTO_AES_ECB },
+    { NID_aes_192_ecb, 16, 192 / 8, 0, EVP_CIPH_ECB_MODE, CRYPTO_AES_ECB },
+    { NID_aes_256_ecb, 16, 256 / 8, 0, EVP_CIPH_ECB_MODE, CRYPTO_AES_ECB },
+#endif
+#if 0                            /* Not yet supported */
+    { NID_aes_128_gcm, 16, 128 / 8, 16, EVP_CIPH_GCM_MODE, CRYPTO_AES_GCM },
+    { NID_aes_192_gcm, 16, 192 / 8, 16, EVP_CIPH_GCM_MODE, CRYPTO_AES_GCM },
+    { NID_aes_256_gcm, 16, 256 / 8, 16, EVP_CIPH_GCM_MODE, CRYPTO_AES_GCM },
+#endif
+#ifndef OPENSSL_NO_CAMELLIA
+    { NID_camellia_128_cbc, 16, 128 / 8, 16, EVP_CIPH_CBC_MODE,
+      CRYPTO_CAMELLIA_CBC },
+    { NID_camellia_192_cbc, 16, 192 / 8, 16, EVP_CIPH_CBC_MODE,
+      CRYPTO_CAMELLIA_CBC },
+    { NID_camellia_256_cbc, 16, 256 / 8, 16, EVP_CIPH_CBC_MODE,
+      CRYPTO_CAMELLIA_CBC },
+#endif
+};
+
+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
+     * are used.  If any other NID reaches this function, there's a grave
+     * coding error further down.
+     */
+    assert("Code that never should be reached" == NULL);
+    return -1;
+}
+
+static const struct cipher_data_st *get_cipher_data(int nid)
+{
+    return &cipher_data[get_cipher_data_index(nid)];
+}
+
+/*
+ * Following are the three necessary functions to map OpenSSL functionality
+ * with cryptodev.
+ */
+
+static int cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+                       const unsigned char *iv, int enc)
+{
+    struct cipher_ctx *cipher_ctx =
+        (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
+    const struct cipher_data_st *cipher_d =
+        get_cipher_data(EVP_CIPHER_CTX_nid(ctx));
+
+    memset(&cipher_ctx->sess, 0, sizeof(cipher_ctx->sess));
+    cipher_ctx->sess.cipher = cipher_d->devcryptoid;
+    cipher_ctx->sess.keylen = cipher_d->keylen;
+    cipher_ctx->sess.key = (void *)key;
+    cipher_ctx->op = enc ? COP_ENCRYPT : COP_DECRYPT;
+    cipher_ctx->mode = cipher_d->flags & EVP_CIPH_MODE;
+    cipher_ctx->blocksize = cipher_d->blocksize;
+    if (ioctl(cfd, CIOCGSESSION, &cipher_ctx->sess) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+
+    return 1;
+}
+
+static int cipher_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
+                            const unsigned char *in, size_t inl)
+{
+    struct cipher_ctx *cipher_ctx =
+        (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
+    struct crypt_op cryp;
+    unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
+#if !defined(COP_FLAG_WRITE_IV)
+    unsigned char saved_iv[EVP_MAX_IV_LENGTH];
+    const unsigned char *ivptr;
+    size_t nblocks, ivlen;
+#endif
+
+    memset(&cryp, 0, sizeof(cryp));
+    cryp.ses = cipher_ctx->sess.ses;
+    cryp.len = inl;
+    cryp.src = (void *)in;
+    cryp.dst = (void *)out;
+    cryp.iv = (void *)iv;
+    cryp.op = cipher_ctx->op;
+#if !defined(COP_FLAG_WRITE_IV)
+    cryp.flags = 0;
+
+    ivlen = EVP_CIPHER_CTX_iv_length(ctx);
+    if (ivlen > 0)
+        switch (cipher_ctx->mode) {
+        case EVP_CIPH_CBC_MODE:
+            assert(inl >= ivlen);
+            if (!EVP_CIPHER_CTX_encrypting(ctx)) {
+                ivptr = in + inl - ivlen;
+                memcpy(saved_iv, ivptr, ivlen);
+            }
+            break;
+
+        case EVP_CIPH_CTR_MODE:
+            break;
+
+        default: /* should not happen */
+            return 0;
+        }
+#else
+    cryp.flags = COP_FLAG_WRITE_IV;
+#endif
+
+    if (ioctl(cfd, CIOCCRYPT, &cryp) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+
+#if !defined(COP_FLAG_WRITE_IV)
+    if (ivlen > 0)
+        switch (cipher_ctx->mode) {
+        case EVP_CIPH_CBC_MODE:
+            assert(inl >= ivlen);
+            if (EVP_CIPHER_CTX_encrypting(ctx))
+                ivptr = out + inl - ivlen;
+            else
+                ivptr = saved_iv;
+
+            memcpy(iv, ivptr, ivlen);
+            break;
+
+        case EVP_CIPH_CTR_MODE:
+            nblocks = (inl + cipher_ctx->blocksize - 1)
+                      / cipher_ctx->blocksize;
+            do {
+                ivlen--;
+                nblocks += iv[ivlen];
+                iv[ivlen] = (uint8_t) nblocks;
+                nblocks >>= 8;
+            } while (ivlen);
+            break;
+
+        default: /* should not happen */
+            return 0;
+        }
+#endif
+
+    return 1;
+}
+
+static int ctr_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
+                         const unsigned char *in, size_t inl)
+{
+    struct cipher_ctx *cipher_ctx =
+        (struct cipher_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
+    size_t nblocks, len;
+
+    /* initial partial block */
+    while (cipher_ctx->num && inl) {
+        (*out++) = *(in++) ^ cipher_ctx->partial[cipher_ctx->num];
+        --inl;
+        cipher_ctx->num = (cipher_ctx->num + 1) % cipher_ctx->blocksize;
+    }
+
+    /* full blocks */
+    if (inl > (unsigned int) cipher_ctx->blocksize) {
+        nblocks = inl/cipher_ctx->blocksize;
+        len = nblocks * cipher_ctx->blocksize;
+        if (cipher_do_cipher(ctx, out, in, len) < 1)
+            return 0;
+        inl -= len;
+        out += len;
+        in += len;
+    }
+
+    /* final partial block */
+    if (inl) {
+        memset(cipher_ctx->partial, 0, cipher_ctx->blocksize);
+        if (cipher_do_cipher(ctx, cipher_ctx->partial, cipher_ctx->partial,
+            cipher_ctx->blocksize) < 1)
+            return 0;
+        while (inl--) {
+            out[cipher_ctx->num] = in[cipher_ctx->num]
+                                   ^ cipher_ctx->partial[cipher_ctx->num];
+            cipher_ctx->num++;
+        }
+    }
+
+    return 1;
+}
+
+static int cipher_ctrl(EVP_CIPHER_CTX *ctx, int type, int p1, void* p2)
+{
+    EVP_CIPHER_CTX *to_ctx = (EVP_CIPHER_CTX *)p2;
+    struct cipher_ctx *cipher_ctx;
+
+    if (type == EVP_CTRL_COPY) {
+        /* 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),
+                           (cipher_ctx->op == COP_ENCRYPT));
+    }
+
+    return -1;
+}
+
+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;
+}
+
+/*
+ * 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 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";
+
+    for (i = 0, known_cipher_nids_amount = 0;
+         i < OSSL_NELEM(cipher_data); i++) {
+
+        selected_ciphers[i] = 1;
+        /*
+         * Check that the cipher is usable
+         */
+        sess.cipher = cipher_data[i].devcryptoid;
+        sess.keylen = cipher_data[i].keylen;
+        if (ioctl(cfd, CIOCGSESSION, &sess) < 0) {
+            cipher_driver_info[i].status = DEVCRYPTO_STATUS_NO_CIOCGSESSION;
+            continue;
+        }
+
+        cipher_mode = cipher_data[i].flags & EVP_CIPH_MODE;
+
+        if ((known_cipher_methods[i] =
+                 EVP_CIPHER_meth_new(cipher_data[i].nid,
+                                     cipher_mode == EVP_CIPH_CTR_MODE ? 1 :
+                                                    cipher_data[i].blocksize,
+                                     cipher_data[i].keylen)) == NULL
+            || !EVP_CIPHER_meth_set_iv_length(known_cipher_methods[i],
+                                              cipher_data[i].ivlen)
+            || !EVP_CIPHER_meth_set_flags(known_cipher_methods[i],
+                                          cipher_data[i].flags
+                                          | EVP_CIPH_CUSTOM_COPY
+                                          | 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],
+                                     cipher_mode == EVP_CIPH_CTR_MODE ?
+                                              ctr_do_cipher :
+                                              cipher_do_cipher)
+            || !EVP_CIPHER_meth_set_ctrl(known_cipher_methods[i], cipher_ctrl)
+            || !EVP_CIPHER_meth_set_cleanup(known_cipher_methods[i],
+                                            cipher_cleanup)
+            || !EVP_CIPHER_meth_set_impl_ctx_size(known_cipher_methods[i],
+                                                  sizeof(struct cipher_ctx))) {
+            cipher_driver_info[i].status = DEVCRYPTO_STATUS_FAILURE;
+            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 {
+                cipher_driver_info[i].driver_name =
+                    OPENSSL_strndup(siop.cipher_info.cra_driver_name,
+                                    CRYPTODEV_MAX_ALG_NAME);
+                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);
+
+    if (i == (size_t)-1)
+        return NULL;
+    return known_cipher_methods[i];
+}
+
+static int get_cipher_nids(const int **nids)
+{
+    *nids = known_cipher_nids;
+    return known_cipher_nids_amount;
+}
+
+static void destroy_cipher_method(int nid)
+{
+    size_t i = get_cipher_data_index(nid);
+
+    EVP_CIPHER_meth_free(known_cipher_methods[i]);
+    known_cipher_methods[i] = NULL;
+}
+
+static void destroy_all_cipher_methods(void)
+{
+    size_t i;
+
+    for (i = 0; i < OSSL_NELEM(cipher_data); i++) {
+        destroy_cipher_method(cipher_data[i].nid);
+        OPENSSL_free(cipher_driver_info[i].driver_name);
+        cipher_driver_info[i].driver_name = NULL;
+    }
+}
+
+static int devcrypto_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
+                             const int **nids, int nid)
+{
+    if (cipher == NULL)
+        return get_cipher_nids(nids);
+
+    *cipher = get_cipher_method(nid);
+
+    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;
+}
+
+static void dump_cipher_info(void)
+{
+    size_t i;
+    const char *name;
+
+    fprintf (stderr, "Information about ciphers supported by the /dev/crypto"
+             " engine:\n");
+#ifndef CIOCGSESSINFO
+    fprintf(stderr, "CIOCGSESSINFO (session info call) unavailable\n");
+#endif
+    for (i = 0; i < OSSL_NELEM(cipher_data); i++) {
+        name = OBJ_nid2sn(cipher_data[i].nid);
+        fprintf (stderr, "Cipher %s, NID=%d, /dev/crypto info: id=%d, ",
+                 name ? name : "unknown", cipher_data[i].nid,
+                 cipher_data[i].devcryptoid);
+        if (cipher_driver_info[i].status == DEVCRYPTO_STATUS_NO_CIOCGSESSION ) {
+            fprintf (stderr, "CIOCGSESSION (session open call) failed\n");
+            continue;
+        }
+        fprintf (stderr, "driver=%s ", cipher_driver_info[i].driver_name ?
+                 cipher_driver_info[i].driver_name : "unknown");
+        if (cipher_driver_info[i].accelerated == DEVCRYPTO_ACCELERATED)
+            fprintf(stderr, "(hw accelerated)");
+        else if (cipher_driver_info[i].accelerated == DEVCRYPTO_NOT_ACCELERATED)
+            fprintf(stderr, "(software)");
+        else
+            fprintf(stderr, "(acceleration status unknown)");
+        if (cipher_driver_info[i].status == DEVCRYPTO_STATUS_FAILURE)
+            fprintf (stderr, ". Cipher setup failed");
+        fprintf(stderr, "\n");
+    }
+    fprintf(stderr, "\n");
+}
+
+/*
+ * We only support digests if the cryptodev implementation supports multiple
+ * data updates and session copying.  Otherwise, we would be forced to maintain
+ * a cache, which is perilous if there's a lot of data coming in (if someone
+ * wants to checksum an OpenSSL tarball, for example).
+ */
+#if defined(CIOCCPHASH) && defined(COP_FLAG_UPDATE) && defined(COP_FLAG_FINAL)
+#define IMPLEMENT_DIGEST
+
+/******************************************************************************
+ *
+ * Digests
+ *
+ * Because they all do the same basic operation, we have only one set of
+ * method functions for them all to share, and a mapping table between
+ * NIDs and cryptodev IDs, with all the necessary size data.
+ *
+ *****/
+
+struct digest_ctx {
+    struct session_op sess;
+    /* This signals that the init function was called, not that it succeeded. */
+    int init_called;
+    unsigned char digest_res[HASH_MAX_LEN];
+};
+
+static const struct digest_data_st {
+    int nid;
+    int digestlen;
+    int devcryptoid;
+} digest_data[] = {
+#ifndef OPENSSL_NO_MD5
+    { NID_md5, 16, CRYPTO_MD5 },
+#endif
+    { NID_sha1, 20, CRYPTO_SHA1 },
+#ifndef OPENSSL_NO_RMD160
+# if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_RIPEMD160)
+    { NID_ripemd160, 20, CRYPTO_RIPEMD160 },
+# endif
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_SHA2_224)
+    { NID_sha224, 224 / 8, CRYPTO_SHA2_224 },
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_SHA2_256)
+    { NID_sha256, 256 / 8, CRYPTO_SHA2_256 },
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_SHA2_384)
+    { NID_sha384, 384 / 8, CRYPTO_SHA2_384 },
+#endif
+#if !defined(CHECK_BSD_STYLE_MACROS) || defined(CRYPTO_SHA2_512)
+    { NID_sha512, 512 / 8, CRYPTO_SHA2_512 },
+#endif
+};
+
+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
+     * are used.  If any other NID reaches this function, there's a grave
+     * coding error further down.
+     */
+    assert("Code that never should be reached" == NULL);
+    return -1;
+}
+
+static const struct digest_data_st *get_digest_data(int nid)
+{
+    return &digest_data[get_digest_data_index(nid)];
+}
+
+/*
+ * 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)
+{
+    struct digest_ctx *digest_ctx =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(ctx);
+    const struct digest_data_st *digest_d =
+        get_digest_data(EVP_MD_CTX_type(ctx));
+
+    digest_ctx->init_called = 1;
+
+    memset(&digest_ctx->sess, 0, sizeof(digest_ctx->sess));
+    digest_ctx->sess.mac = digest_d->devcryptoid;
+    if (ioctl(cfd, CIOCGSESSION, &digest_ctx->sess) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+
+    return 1;
+}
+
+static int digest_op(struct digest_ctx *ctx, const void *src, size_t srclen,
+                     void *res, unsigned int flags)
+{
+    struct crypt_op cryp;
+
+    memset(&cryp, 0, sizeof(cryp));
+    cryp.ses = ctx->sess.ses;
+    cryp.len = srclen;
+    cryp.src = (void *)src;
+    cryp.dst = NULL;
+    cryp.mac = res;
+    cryp.flags = flags;
+    return ioctl(cfd, CIOCCRYPT, &cryp);
+}
+
+static int digest_update(EVP_MD_CTX *ctx, const void *data, size_t count)
+{
+    struct digest_ctx *digest_ctx =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(ctx);
+
+    if (count == 0)
+        return 1;
+
+    if (digest_ctx == NULL)
+        return 0;
+
+    if (EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT)) {
+        if (digest_op(digest_ctx, data, count, digest_ctx->digest_res, 0) >= 0)
+            return 1;
+    } else if (digest_op(digest_ctx, data, count, NULL, COP_FLAG_UPDATE) >= 0) {
+        return 1;
+    }
+
+    SYSerr(SYS_F_IOCTL, errno);
+    return 0;
+}
+
+static int digest_final(EVP_MD_CTX *ctx, unsigned char *md)
+{
+    struct digest_ctx *digest_ctx =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(ctx);
+
+    if (md == NULL || digest_ctx == NULL)
+        return 0;
+
+    if (EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_ONESHOT)) {
+        memcpy(md, digest_ctx->digest_res, EVP_MD_CTX_size(ctx));
+    } else if (digest_op(digest_ctx, NULL, 0, md, COP_FLAG_FINAL) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+
+    return 1;
+}
+
+static int digest_copy(EVP_MD_CTX *to, const EVP_MD_CTX *from)
+{
+    struct digest_ctx *digest_from =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(from);
+    struct digest_ctx *digest_to =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(to);
+    struct cphash_op cphash;
+
+    if (digest_from == NULL || digest_from->init_called != 1)
+        return 1;
+
+    if (!digest_init(to)) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+
+    cphash.src_ses = digest_from->sess.ses;
+    cphash.dst_ses = digest_to->sess.ses;
+    if (ioctl(cfd, CIOCCPHASH, &cphash) < 0) {
+        SYSerr(SYS_F_IOCTL, errno);
+        return 0;
+    }
+    return 1;
+}
+
+static int digest_cleanup(EVP_MD_CTX *ctx)
+{
+    struct digest_ctx *digest_ctx =
+        (struct digest_ctx *)EVP_MD_CTX_md_data(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;
+}
+
+/*
+ * 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 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 digest is usable
+         */
+        sess1.mac = digest_data[i].devcryptoid;
+        sess2.ses = 0;
+        if (ioctl(cfd, CIOCGSESSION, &sess1) < 0) {
+            digest_driver_info[i].status = DEVCRYPTO_STATUS_NO_CIOCGSESSION;
+            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 {
+            digest_driver_info[i].driver_name =
+                OPENSSL_strndup(siop.hash_info.cra_driver_name,
+                                CRYPTODEV_MAX_ALG_NAME);
+            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_FAILURE;
+            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_NO_CIOCCPHASH;
+            goto finish;
+        }
+        if ((known_digest_methods[i] = EVP_MD_meth_new(digest_data[i].nid,
+                                                       NID_undef)) == NULL
+            || !EVP_MD_meth_set_result_size(known_digest_methods[i],
+                                            digest_data[i].digestlen)
+            || !EVP_MD_meth_set_init(known_digest_methods[i], digest_init)
+            || !EVP_MD_meth_set_update(known_digest_methods[i], digest_update)
+            || !EVP_MD_meth_set_final(known_digest_methods[i], digest_final)
+            || !EVP_MD_meth_set_copy(known_digest_methods[i], digest_copy)
+            || !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_FAILURE;
+            EVP_MD_meth_free(known_digest_methods[i]);
+            known_digest_methods[i] = NULL;
+            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;
+    }
+}
+
+static const EVP_MD *get_digest_method(int nid)
+{
+    size_t i = get_digest_data_index(nid);
+
+    if (i == (size_t)-1)
+        return NULL;
+    return known_digest_methods[i];
+}
+
+static int get_digest_nids(const int **nids)
+{
+    *nids = known_digest_nids;
+    return known_digest_nids_amount;
+}
+
+static void destroy_digest_method(int nid)
+{
+    size_t i = get_digest_data_index(nid);
+
+    EVP_MD_meth_free(known_digest_methods[i]);
+    known_digest_methods[i] = NULL;
+}
+
+static void destroy_all_digest_methods(void)
+{
+    size_t i;
+
+    for (i = 0; i < OSSL_NELEM(digest_data); i++) {
+        destroy_digest_method(digest_data[i].nid);
+        OPENSSL_free(digest_driver_info[i].driver_name);
+        digest_driver_info[i].driver_name = NULL;
+    }
+}
+
+static int devcrypto_digests(ENGINE *e, const EVP_MD **digest,
+                             const int **nids, int nid)
+{
+    if (digest == NULL)
+        return get_digest_nids(nids);
+
+    *digest = get_digest_method(nid);
+
+    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;
+}
+
+static void dump_digest_info(void)
+{
+    size_t i;
+    const char *name;
+
+    fprintf (stderr, "Information about digests supported by the /dev/crypto"
+             " engine:\n");
+#ifndef CIOCGSESSINFO
+    fprintf(stderr, "CIOCGSESSINFO (session info call) unavailable\n");
+#endif
+
+    for (i = 0; i < OSSL_NELEM(digest_data); i++) {
+        name = OBJ_nid2sn(digest_data[i].nid);
+        fprintf (stderr, "Digest %s, NID=%d, /dev/crypto info: id=%d, driver=%s",
+                 name ? name : "unknown", digest_data[i].nid,
+                 digest_data[i].devcryptoid,
+                 digest_driver_info[i].driver_name ? digest_driver_info[i].driver_name : "unknown");
+        if (digest_driver_info[i].status == DEVCRYPTO_STATUS_NO_CIOCGSESSION) {
+            fprintf (stderr, ". CIOCGSESSION (session open) failed\n");
+            continue;
+        }
+        if (digest_driver_info[i].accelerated == DEVCRYPTO_ACCELERATED)
+            fprintf(stderr, " (hw accelerated)");
+        else if (digest_driver_info[i].accelerated == DEVCRYPTO_NOT_ACCELERATED)
+            fprintf(stderr, " (software)");
+        else
+            fprintf(stderr, " (acceleration status unknown)");
+        if (cipher_driver_info[i].status == DEVCRYPTO_STATUS_FAILURE)
+            fprintf (stderr, ". Cipher setup failed\n");
+        else if (digest_driver_info[i].status == DEVCRYPTO_STATUS_NO_CIOCCPHASH)
+            fprintf(stderr, ", CIOCCPHASH failed\n");
+        else
+            fprintf(stderr, ", CIOCCPHASH capable\n");
+    }
+    fprintf(stderr, "\n");
+}
+
+#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)
+
+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
+
+   {DEVCRYPTO_CMD_DUMP_INFO,
+    "DUMP_INFO",
+    "dump info about each algorithm to stderr; use 'openssl engine -pre DUMP_INFO devcrypto'",
+    ENGINE_CMD_FLAG_NO_INPUT},
+
+   {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 */
+
+    case DEVCRYPTO_CMD_DUMP_INFO:
+        dump_cipher_info();
+#ifdef IMPLEMENT_DIGEST
+        dump_digest_info();
+#endif
+        return 1;
+
+    default:
+        break;
+    }
+    return 0;
+}
+
+/******************************************************************************
+ *
+ * LOAD / UNLOAD
+ *
+ *****/
+
+/*
+ * Opens /dev/crypto
+ */
+static int open_devcrypto(void)
+{
+    if (cfd >= 0)
+        return 1;
+
+    if ((cfd = open("/dev/crypto", O_RDWR, 0)) < 0) {
+#ifndef ENGINE_DEVCRYPTO_DEBUG
+        if (errno != ENOENT)
+#endif
+            fprintf(stderr, "Could not open /dev/crypto: %s\n", strerror(errno));
+        return 0;
+    }
+
+    return 1;
+}
+
+static int close_devcrypto(void)
+{
+    if (cfd < 0)
+        return 1;
+    cfd = -1;
+    if (close(cfd) == 0) {
+        fprintf(stderr, "Error closing /dev/crypto: %s\n", strerror(errno));
+        return 0;
+    }
+    return 1;
+}
+
+static int devcrypto_unload(ENGINE *e)
+{
+    destroy_all_cipher_methods();
+#ifdef IMPLEMENT_DIGEST
+    destroy_all_digest_methods();
+#endif
+
+    close_devcrypto();
+
+    return 1;
+}
+
+static int bind_devcrypto(ENGINE *e) {
+
+    if (!ENGINE_set_id(e, engine_devcrypto_id)
+        || !ENGINE_set_name(e, "/dev/crypto engine")
+        || !ENGINE_set_destroy_function(e, devcrypto_unload)
+        || !ENGINE_set_cmd_defns(e, devcrypto_cmds)
+        || !ENGINE_set_ctrl_function(e, devcrypto_ctrl))
+        return 0;
+
+    prepare_cipher_methods();
+#ifdef IMPLEMENT_DIGEST
+    prepare_digest_methods();
+#endif
+
+    return (ENGINE_set_ciphers(e, devcrypto_ciphers)
+#ifdef IMPLEMENT_DIGEST
+        && ENGINE_set_digests(e, devcrypto_digests)
+#endif
+/*
+ * Asymmetric ciphers aren't well supported with /dev/crypto.  Among the BSD
+ * implementations, it seems to only exist in FreeBSD, and regarding the
+ * parameters in its crypt_kop, the manual crypto(4) has this to say:
+ *
+ *    The semantics of these arguments are currently undocumented.
+ *
+ * Reading through the FreeBSD source code doesn't give much more than
+ * their CRK_MOD_EXP implementation for ubsec.
+ *
+ * It doesn't look much better with cryptodev-linux.  They have the crypt_kop
+ * structure as well as the command (CRK_*) in cryptodev.h, but no support
+ * seems to be implemented at all for the moment.
+ *
+ * At the time of writing, it seems impossible to write proper support for
+ * FreeBSD's asym features without some very deep knowledge and access to
+ * specific kernel modules.
+ *
+ * /Richard Levitte, 2017-05-11
+ */
+#if 0
+# ifndef OPENSSL_NO_RSA
+        && ENGINE_set_RSA(e, devcrypto_rsa)
+# endif
+# ifndef OPENSSL_NO_DSA
+        && ENGINE_set_DSA(e, devcrypto_dsa)
+# endif
+# ifndef OPENSSL_NO_DH
+        && ENGINE_set_DH(e, devcrypto_dh)
+# endif
+# ifndef OPENSSL_NO_EC
+        && ENGINE_set_EC(e, devcrypto_ec)
+# endif
+#endif
+        );
+}
+
+#ifdef OPENSSL_NO_DYNAMIC_ENGINE
+/*
+ * In case this engine is built into libcrypto, then it doesn't offer any
+ * ability to be dynamically loadable.
+ */
+void engine_load_devcrypto_int(void)
+{
+    ENGINE *e = NULL;
+
+    if (!open_devcrypto())
+        return;
+
+    if ((e = ENGINE_new()) == NULL
+        || !bind_devcrypto(e)) {
+        close_devcrypto();
+        ENGINE_free(e);
+        return;
+    }
+
+    ENGINE_add(e);
+    ENGINE_free(e);          /* Loose our local reference */
+    ERR_clear_error();
+}
+
+#else
+
+static int bind_helper(ENGINE *e, const char *id)
+{
+    if ((id && (strcmp(id, engine_devcrypto_id) != 0))
+        || !open_devcrypto())
+        return 0;
+    if (!bind_devcrypto(e)) {
+        close_devcrypto();
+        return 0;
+    }
+    return 1;
+}
+
+IMPLEMENT_DYNAMIC_CHECK_FN()
+IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
+
+#endif