€•T;      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ&/translations/zh_CN/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ&/translations/zh_TW/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ&/translations/it_IT/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ&/translations/ja_JP/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ&/translations/ko_KR/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ&/translations/sp_SP/crypto/api-samples”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒCode Examples”h]”hŒCode Examples”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ@/var/lib/git/docbuild/linux/Documentation/crypto/api-samples.rst”h Kubh¢)”}”(hhh]”(h§)”}”(hŒ/Code Example For Symmetric Key Cipher Operation”h]”hŒ/Code Example For Symmetric Key Cipher Operation”…””}”(hhºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh·hžhhŸh¶h KubhŒ	paragraph”“”)”}”(hŒÈThis code encrypts some data with AES-256-XTS.  For sake of example,
all inputs are random bytes, the encryption is done in-place, and it's
assumed the code is running in a context where it can sleep.”h]”hŒÊThis code encrypts some data with AES-256-XTS.  For sake of example,
all inputs are random bytes, the encryption is done in-place, and itâ€™s
assumed the code is running in a context where it can sleep.”…””}”(hhÊhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÈhŸh¶h Khh·hžhubhŒliteral_block”“”)”}”(hXs
  static int test_skcipher(void)
{
        struct crypto_skcipher *tfm = NULL;
        struct skcipher_request *req = NULL;
        u8 *data = NULL;
        const size_t datasize = 512; /* data size in bytes */
        struct scatterlist sg;
        DECLARE_CRYPTO_WAIT(wait);
        u8 iv[16];  /* AES-256-XTS takes a 16-byte IV */
        u8 key[64]; /* AES-256-XTS takes a 64-byte key */
        int err;

        /*
         * Allocate a tfm (a transformation object) and set the key.
         *
         * In real-world use, a tfm and key are typically used for many
         * encryption/decryption operations.  But in this example, we'll just do a
         * single encryption operation with it (which is not very efficient).
         */

        tfm = crypto_alloc_skcipher("xts(aes)", 0, 0);
        if (IS_ERR(tfm)) {
                pr_err("Error allocating xts(aes) handle: %ld\n", PTR_ERR(tfm));
                return PTR_ERR(tfm);
        }

        get_random_bytes(key, sizeof(key));
        err = crypto_skcipher_setkey(tfm, key, sizeof(key));
        if (err) {
                pr_err("Error setting key: %d\n", err);
                goto out;
        }

        /* Allocate a request object */
        req = skcipher_request_alloc(tfm, GFP_KERNEL);
        if (!req) {
                err = -ENOMEM;
                goto out;
        }

        /* Prepare the input data */
        data = kmalloc(datasize, GFP_KERNEL);
        if (!data) {
                err = -ENOMEM;
                goto out;
        }
        get_random_bytes(data, datasize);

        /* Initialize the IV */
        get_random_bytes(iv, sizeof(iv));

        /*
         * Encrypt the data in-place.
         *
         * For simplicity, in this example we wait for the request to complete
         * before proceeding, even if the underlying implementation is asynchronous.
         *
         * To decrypt instead of encrypt, just change crypto_skcipher_encrypt() to
         * crypto_skcipher_decrypt().
         */
        sg_init_one(&sg, data, datasize);
        skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
                                           CRYPTO_TFM_REQ_MAY_SLEEP,
                                      crypto_req_done, &wait);
        skcipher_request_set_crypt(req, &sg, &sg, datasize, iv);
        err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
        if (err) {
                pr_err("Error encrypting data: %d\n", err);
                goto out;
        }

        pr_debug("Encryption was successful\n");
out:
        crypto_free_skcipher(tfm);
        skcipher_request_free(req);
        kfree(data);
        return err;
}”h]”hXs
  static int test_skcipher(void)
{
        struct crypto_skcipher *tfm = NULL;
        struct skcipher_request *req = NULL;
        u8 *data = NULL;
        const size_t datasize = 512; /* data size in bytes */
        struct scatterlist sg;
        DECLARE_CRYPTO_WAIT(wait);
        u8 iv[16];  /* AES-256-XTS takes a 16-byte IV */
        u8 key[64]; /* AES-256-XTS takes a 64-byte key */
        int err;

        /*
         * Allocate a tfm (a transformation object) and set the key.
         *
         * In real-world use, a tfm and key are typically used for many
         * encryption/decryption operations.  But in this example, we'll just do a
         * single encryption operation with it (which is not very efficient).
         */

        tfm = crypto_alloc_skcipher("xts(aes)", 0, 0);
        if (IS_ERR(tfm)) {
                pr_err("Error allocating xts(aes) handle: %ld\n", PTR_ERR(tfm));
                return PTR_ERR(tfm);
        }

        get_random_bytes(key, sizeof(key));
        err = crypto_skcipher_setkey(tfm, key, sizeof(key));
        if (err) {
                pr_err("Error setting key: %d\n", err);
                goto out;
        }

        /* Allocate a request object */
        req = skcipher_request_alloc(tfm, GFP_KERNEL);
        if (!req) {
                err = -ENOMEM;
                goto out;
        }

        /* Prepare the input data */
        data = kmalloc(datasize, GFP_KERNEL);
        if (!data) {
                err = -ENOMEM;
                goto out;
        }
        get_random_bytes(data, datasize);

        /* Initialize the IV */
        get_random_bytes(iv, sizeof(iv));

        /*
         * Encrypt the data in-place.
         *
         * For simplicity, in this example we wait for the request to complete
         * before proceeding, even if the underlying implementation is asynchronous.
         *
         * To decrypt instead of encrypt, just change crypto_skcipher_encrypt() to
         * crypto_skcipher_decrypt().
         */
        sg_init_one(&sg, data, datasize);
        skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
                                           CRYPTO_TFM_REQ_MAY_SLEEP,
                                      crypto_req_done, &wait);
        skcipher_request_set_crypt(req, &sg, &sg, datasize, iv);
        err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
        if (err) {
                pr_err("Error encrypting data: %d\n", err);
                goto out;
        }

        pr_debug("Encryption was successful\n");
out:
        crypto_free_skcipher(tfm);
        skcipher_request_free(req);
        kfree(data);
        return err;
}”…””}”hhÚsbah}”(h]”h ]”h"]”h$]”h&]”Œ	xml:space”Œpreserve”uh1hØhŸh¶h Khh·hžhubeh}”(h]”Œ/code-example-for-symmetric-key-cipher-operation”ah ]”h"]”Œ/code example for symmetric key cipher operation”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒ;Code Example For Use of Operational State Memory With SHASH”h]”hŒ;Code Example For Use of Operational State Memory With SHASH”…””}”(hhõhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hhòhžhhŸh¶h K^ubhÙ)”}”(hXê  struct sdesc {
    struct shash_desc shash;
    char ctx[];
};

static struct sdesc *init_sdesc(struct crypto_shash *alg)
{
    struct sdesc *sdesc;
    int size;

    size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
    sdesc = kmalloc(size, GFP_KERNEL);
    if (!sdesc)
        return ERR_PTR(-ENOMEM);
    sdesc->shash.tfm = alg;
    return sdesc;
}

static int calc_hash(struct crypto_shash *alg,
             const unsigned char *data, unsigned int datalen,
             unsigned char *digest)
{
    struct sdesc *sdesc;
    int ret;

    sdesc = init_sdesc(alg);
    if (IS_ERR(sdesc)) {
        pr_info("can't alloc sdesc\n");
        return PTR_ERR(sdesc);
    }

    ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
    kfree(sdesc);
    return ret;
}

static int test_hash(const unsigned char *data, unsigned int datalen,
             unsigned char *digest)
{
    struct crypto_shash *alg;
    char *hash_alg_name = "sha1-padlock-nano";
    int ret;

    alg = crypto_alloc_shash(hash_alg_name, 0, 0);
    if (IS_ERR(alg)) {
            pr_info("can't alloc alg %s\n", hash_alg_name);
            return PTR_ERR(alg);
    }
    ret = calc_hash(alg, data, datalen, digest);
    crypto_free_shash(alg);
    return ret;
}”h]”hXê  struct sdesc {
    struct shash_desc shash;
    char ctx[];
};

static struct sdesc *init_sdesc(struct crypto_shash *alg)
{
    struct sdesc *sdesc;
    int size;

    size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
    sdesc = kmalloc(size, GFP_KERNEL);
    if (!sdesc)
        return ERR_PTR(-ENOMEM);
    sdesc->shash.tfm = alg;
    return sdesc;
}

static int calc_hash(struct crypto_shash *alg,
             const unsigned char *data, unsigned int datalen,
             unsigned char *digest)
{
    struct sdesc *sdesc;
    int ret;

    sdesc = init_sdesc(alg);
    if (IS_ERR(sdesc)) {
        pr_info("can't alloc sdesc\n");
        return PTR_ERR(sdesc);
    }

    ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
    kfree(sdesc);
    return ret;
}

static int test_hash(const unsigned char *data, unsigned int datalen,
             unsigned char *digest)
{
    struct crypto_shash *alg;
    char *hash_alg_name = "sha1-padlock-nano";
    int ret;

    alg = crypto_alloc_shash(hash_alg_name, 0, 0);
    if (IS_ERR(alg)) {
            pr_info("can't alloc alg %s\n", hash_alg_name);
            return PTR_ERR(alg);
    }
    ret = calc_hash(alg, data, datalen, digest);
    crypto_free_shash(alg);
    return ret;
}”…””}”hj  sbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h Kchhòhžhubeh}”(h]”Œ;code-example-for-use-of-operational-state-memory-with-shash”ah ]”h"]”Œ;code example for use of operational state memory with shash”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K^ubh¢)”}”(hhh]”(h§)”}”(hŒ.Code Example For Random Number Generator Usage”h]”hŒ.Code Example For Random Number Generator Usage”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj  hžhhŸh¶h KšubhÙ)”}”(hXò  static int get_random_numbers(u8 *buf, unsigned int len)
{
    struct crypto_rng *rng = NULL;
    char *drbg = "drbg_nopr_sha256"; /* Hash DRBG with SHA-256, no PR */
    int ret;

    if (!buf || !len) {
        pr_debug("No output buffer provided\n");
        return -EINVAL;
    }

    rng = crypto_alloc_rng(drbg, 0, 0);
    if (IS_ERR(rng)) {
        pr_debug("could not allocate RNG handle for %s\n", drbg);
        return PTR_ERR(rng);
    }

    ret = crypto_rng_get_bytes(rng, buf, len);
    if (ret < 0)
        pr_debug("generation of random numbers failed\n");
    else if (ret == 0)
        pr_debug("RNG returned no data");
    else
        pr_debug("RNG returned %d bytes of data\n", ret);

out:
    crypto_free_rng(rng);
    return ret;
}”h]”hXò  static int get_random_numbers(u8 *buf, unsigned int len)
{
    struct crypto_rng *rng = NULL;
    char *drbg = "drbg_nopr_sha256"; /* Hash DRBG with SHA-256, no PR */
    int ret;

    if (!buf || !len) {
        pr_debug("No output buffer provided\n");
        return -EINVAL;
    }

    rng = crypto_alloc_rng(drbg, 0, 0);
    if (IS_ERR(rng)) {
        pr_debug("could not allocate RNG handle for %s\n", drbg);
        return PTR_ERR(rng);
    }

    ret = crypto_rng_get_bytes(rng, buf, len);
    if (ret < 0)
        pr_debug("generation of random numbers failed\n");
    else if (ret == 0)
        pr_debug("RNG returned no data");
    else
        pr_debug("RNG returned %d bytes of data\n", ret);

out:
    crypto_free_rng(rng);
    return ret;
}”…””}”hj*  sbah}”(h]”h ]”h"]”h$]”h&]”hèhéuh1hØhŸh¶h KŸhj  hžhubeh}”(h]”Œ.code-example-for-random-number-generator-usage”ah ]”h"]”Œ.code example for random number generator usage”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kšubeh}”(h]”Œcode-examples”ah ]”h"]”Œcode examples”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jk  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jE  jB  hïhìj  j  j=  j:  uŒ	nametypes”}”(jE  ‰hï‰j  ‰j=  ‰uh}”(jB  h£hìh·j  hòj:  j  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nhžhub.