/*

 * Copyright 2004-2025 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

 */

/*

 * This file uses the low level AES and engine functions (which are deprecated

 * for non-internal use) in order to implement the padlock engine AES ciphers.

 */

#define OPENSSL_SUPPRESS_DEPRECATED

#include <stdio.h>

#include <string.h>

#include <openssl/opensslconf.h>

#include <openssl/crypto.h>

#include <openssl/engine.h>

#include <openssl/evp.h>

#include <openssl/aes.h>

#include <openssl/rand.h>

#include <openssl/err.h>

#include <openssl/modes.h>

#ifndef OPENSSL_NO_PADLOCKENG

/*

 * VIA PadLock AES is available *ONLY* on some x86 CPUs. Not only that it

 * doesn't exist elsewhere, but it even can't be compiled on other platforms!

 */

#undef COMPILE_PADLOCKENG

#if defined(PADLOCK_ASM)

#define COMPILE_PADLOCKENG

#ifdef OPENSSL_NO_DYNAMIC_ENGINE

static ENGINE *ENGINE_padlock(void);

#endif

#endif

#ifdef OPENSSL_NO_DYNAMIC_ENGINE

void engine_load_padlock_int(void);

void engine_load_padlock_int(void)

{

/* On non-x86 CPUs it just returns. */

#ifdef COMPILE_PADLOCKENG

    ENGINE *toadd = ENGINE_padlock();

    if (!toadd)

        return;

    ERR_set_mark();

    ENGINE_add(toadd);

    /*

     * If the "add" worked, it gets a structural reference. So either way, we

     * release our just-created reference.

     */

    ENGINE_free(toadd);

    /*

     * If the "add" didn't work, it was probably a conflict because it was

     * already added (eg. someone calling ENGINE_load_blah then calling

     * ENGINE_load_builtin_engines() perhaps).

     */

    ERR_pop_to_mark();

#endif

}

#endif

#ifdef COMPILE_PADLOCKENG

/* Function for ENGINE detection and control */

static int padlock_available(void);

static int padlock_init(ENGINE *e);

/* RNG Stuff */

static RAND_METHOD padlock_rand;

/* Cipher Stuff */

static int padlock_ciphers(ENGINE *e, const EVP_CIPHER **cipher,

    const int **nids, int nid);

/* Engine names */

static const char *padlock_id = "padlock";

static char padlock_name[100];

/* Available features */

static int padlock_use_ace = 0; /* Advanced Cryptography Engine */

static int padlock_use_rng = 0; /* Random Number Generator */

/* ===== Engine "management" functions ===== */

/* Prepare the ENGINE structure for registration */

static int padlock_bind_helper(ENGINE *e)

{

    /* Check available features */

    padlock_available();

    /*

     * RNG is currently disabled for reasons discussed in commentary just

     * before padlock_rand_bytes function.

     */

    padlock_use_rng = 0;

    /* Generate a nice engine name with available features */

    BIO_snprintf(padlock_name, sizeof(padlock_name),

        "VIA PadLock (%s, %s)",

        padlock_use_rng ? "RNG" : "no-RNG",

        padlock_use_ace ? "ACE" : "no-ACE");

    /* Register everything or return with an error */

    if (!ENGINE_set_id(e, padlock_id) || !ENGINE_set_name(e, padlock_name) || !ENGINE_set_init_function(e, padlock_init) || (padlock_use_ace && !ENGINE_set_ciphers(e, padlock_ciphers)) || (padlock_use_rng && !ENGINE_set_RAND(e, &padlock_rand))) {

        return 0;

    }

    /* Everything looks good */

    return 1;

}

#ifdef OPENSSL_NO_DYNAMIC_ENGINE

/* Constructor */

static ENGINE *ENGINE_padlock(void)

{

    ENGINE *eng = ENGINE_new();

    if (eng == NULL) {

        return NULL;

    }

    if (!padlock_bind_helper(eng)) {

        ENGINE_free(eng);

        return NULL;

    }

    return eng;

}

#endif

/* Check availability of the engine */

static int padlock_init(ENGINE *e)

{

    return (padlock_use_rng || padlock_use_ace);

}

#ifndef AES_ASM

static int padlock_aes_set_encrypt_key(const unsigned char *userKey,

    const int bits,

    AES_KEY *key);

static int padlock_aes_set_decrypt_key(const unsigned char *userKey,

    const int bits,

    AES_KEY *key);

#define AES_ASM

#define AES_set_encrypt_key padlock_aes_set_encrypt_key

#define AES_set_decrypt_key padlock_aes_set_decrypt_key

/* clang-format off */

#   include "../crypto/aes/aes_core.c"

/* clang-format on */

#endif

/*

 * This stuff is needed if this ENGINE is being compiled into a

 * self-contained shared-library.

 */

#ifndef OPENSSL_NO_DYNAMIC_ENGINE

static int padlock_bind_fn(ENGINE *e, const char *id)

{

    if (id && (strcmp(id, padlock_id) != 0)) {

        return 0;

    }

    if (!padlock_bind_helper(e)) {

        return 0;

    }

    return 1;

}

IMPLEMENT_DYNAMIC_CHECK_FN()

IMPLEMENT_DYNAMIC_BIND_FN(padlock_bind_fn)

#endif /* !OPENSSL_NO_DYNAMIC_ENGINE */

/* ===== Here comes the "real" engine ===== */

/* Some AES-related constants */

#define AES_BLOCK_SIZE 16

#define AES_KEY_SIZE_128 16

#define AES_KEY_SIZE_192 24

#define AES_KEY_SIZE_256 32

/*

 * Here we store the status information relevant to the current context.

 */

/*

 * BIG FAT WARNING: Inline assembler in PADLOCK_XCRYPT_ASM() depends on

 * the order of items in this structure.  Don't blindly modify, reorder,

 * etc!

 */

struct padlock_cipher_data {

    unsigned char iv[AES_BLOCK_SIZE]; /* Initialization vector */

    union {

        unsigned int pad[4];

        struct {

            int rounds : 4;

            int dgst : 1; /* n/a in C3 */

            int align : 1; /* n/a in C3 */

            int ciphr : 1; /* n/a in C3 */ /* codespell:ignore */

            unsigned int keygen : 1;

            int interm : 1; /* codespell:ignore */

            unsigned int encdec : 1;

            int ksize : 2;

        } b;

    } cword; /* Control word */

    AES_KEY ks; /* Encryption key */

};

/* Interface to assembler module */

unsigned int padlock_capability(void);

void padlock_key_bswap(AES_KEY *key);

void padlock_verify_context(struct padlock_cipher_data *ctx);

void padlock_reload_key(void);

void padlock_aes_block(void *out, const void *inp,

    struct padlock_cipher_data *ctx);

int padlock_ecb_encrypt(void *out, const void *inp,

    struct padlock_cipher_data *ctx, size_t len);

int padlock_cbc_encrypt(void *out, const void *inp,

    struct padlock_cipher_data *ctx, size_t len);

int padlock_cfb_encrypt(void *out, const void *inp,

    struct padlock_cipher_data *ctx, size_t len);

int padlock_ofb_encrypt(void *out, const void *inp,

    struct padlock_cipher_data *ctx, size_t len);

int padlock_ctr32_encrypt(void *out, const void *inp,

    struct padlock_cipher_data *ctx, size_t len);

int padlock_xstore(void *out, int edx);

void padlock_sha1_oneshot(void *ctx, const void *inp, size_t len);

void padlock_sha1(void *ctx, const void *inp, size_t len);

void padlock_sha256_oneshot(void *ctx, const void *inp, size_t len);

void padlock_sha256(void *ctx, const void *inp, size_t len);

/*

 * Load supported features of the CPU to see if the PadLock is available.

 */

static int padlock_available(void)

{

    unsigned int edx = padlock_capability();

    /* Fill up some flags */

    padlock_use_ace = ((edx & (0x3 << 6)) == (0x3 << 6));

    padlock_use_rng = ((edx & (0x3 << 2)) == (0x3 << 2));

    return padlock_use_ace + padlock_use_rng;

}

/* ===== AES encryption/decryption ===== */

#if defined(NID_aes_128_cfb128) && !defined(NID_aes_128_cfb)

#define NID_aes_128_cfb NID_aes_128_cfb128

#endif

#if defined(NID_aes_128_ofb128) && !defined(NID_aes_128_ofb)

#define NID_aes_128_ofb NID_aes_128_ofb128

#endif

#if defined(NID_aes_192_cfb128) && !defined(NID_aes_192_cfb)

#define NID_aes_192_cfb NID_aes_192_cfb128

#endif

#if defined(NID_aes_192_ofb128) && !defined(NID_aes_192_ofb)

#define NID_aes_192_ofb NID_aes_192_ofb128

#endif

#if defined(NID_aes_256_cfb128) && !defined(NID_aes_256_cfb)

#define NID_aes_256_cfb NID_aes_256_cfb128

#endif

#if defined(NID_aes_256_ofb128) && !defined(NID_aes_256_ofb)

#define NID_aes_256_ofb NID_aes_256_ofb128

#endif

/* List of supported ciphers. */

static const int padlock_cipher_nids[] = {

    NID_aes_128_ecb,

    NID_aes_128_cbc,

    NID_aes_128_cfb,

    NID_aes_128_ofb,

    NID_aes_128_ctr,

    NID_aes_192_ecb,

    NID_aes_192_cbc,

    NID_aes_192_cfb,

    NID_aes_192_ofb,

    NID_aes_192_ctr,

    NID_aes_256_ecb,

    NID_aes_256_cbc,

    NID_aes_256_cfb,

    NID_aes_256_ofb,

    NID_aes_256_ctr

};

static int padlock_cipher_nids_num = (sizeof(padlock_cipher_nids) / sizeof(padlock_cipher_nids[0]));

/* Function prototypes ... */

static int padlock_aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,

    const unsigned char *iv, int enc);

#define NEAREST_ALIGNED(ptr) ((unsigned char *)(ptr) + ((0x10 - ((size_t)(ptr) & 0x0F)) & 0x0F))

#define ALIGNED_CIPHER_DATA(ctx) ((struct padlock_cipher_data *) \

        NEAREST_ALIGNED(EVP_CIPHER_CTX_get_cipher_data(ctx)))

static int

padlock_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,

    const unsigned char *in_arg, size_t nbytes)

{

    return padlock_ecb_encrypt(out_arg, in_arg,

        ALIGNED_CIPHER_DATA(ctx), nbytes);

}

static int

padlock_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,

    const unsigned char *in_arg, size_t nbytes)

{

    struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);

    int ret;

    memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);

    if ((ret = padlock_cbc_encrypt(out_arg, in_arg, cdata, nbytes)))

        memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);

    return ret;

}

static int

padlock_cfb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,

    const unsigned char *in_arg, size_t nbytes)

{

    struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);

    size_t chunk;

    if ((chunk = EVP_CIPHER_CTX_get_num(ctx))) { /* borrow chunk variable */

        unsigned char *ivp = EVP_CIPHER_CTX_iv_noconst(ctx);

        if (chunk >= AES_BLOCK_SIZE)

            return 0; /* bogus value */

        if (EVP_CIPHER_CTX_is_encrypting(ctx))

            while (chunk < AES_BLOCK_SIZE && nbytes != 0) {

                ivp[chunk] = *(out_arg++) = *(in_arg++) ^ ivp[chunk];

                chunk++, nbytes--;

            }

        else

            while (chunk < AES_BLOCK_SIZE && nbytes != 0) {

                unsigned char c = *(in_arg++);

                *(out_arg++) = c ^ ivp[chunk];

                ivp[chunk++] = c, nbytes--;

            }

        EVP_CIPHER_CTX_set_num(ctx, chunk % AES_BLOCK_SIZE);

    }

    if (nbytes == 0)

        return 1;

    memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);

    if ((chunk = nbytes & ~(AES_BLOCK_SIZE - 1))) {

        if (!padlock_cfb_encrypt(out_arg, in_arg, cdata, chunk))

            return 0;

        nbytes -= chunk;

    }

    if (nbytes) {

        unsigned char *ivp = cdata->iv;

        out_arg += chunk;

        in_arg += chunk;

        EVP_CIPHER_CTX_set_num(ctx, (int)nbytes);

        if (cdata->cword.b.encdec) {

            cdata->cword.b.encdec = 0;

            padlock_reload_key();

            padlock_aes_block(ivp, ivp, cdata);

            cdata->cword.b.encdec = 1;

            padlock_reload_key();

            while (nbytes) {

                unsigned char c = *(in_arg++);

                *(out_arg++) = c ^ *ivp;

                *(ivp++) = c, nbytes--;

            }

        } else {

            padlock_reload_key();

            padlock_aes_block(ivp, ivp, cdata);

            padlock_reload_key();

            while (nbytes) {

                *ivp = *(out_arg++) = *(in_arg++) ^ *ivp;

                ivp++, nbytes--;

            }

        }

    }

    memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);

    return 1;

}

static int

padlock_ofb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,

    const unsigned char *in_arg, size_t nbytes)

{

    struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);

    size_t chunk;

    /*

     * ctx->num is maintained in byte-oriented modes, such as CFB and OFB...

     */

    if ((chunk = EVP_CIPHER_CTX_get_num(ctx))) { /* borrow chunk variable */

        unsigned char *ivp = EVP_CIPHER_CTX_iv_noconst(ctx);

        if (chunk >= AES_BLOCK_SIZE)

            return 0; /* bogus value */

        while (chunk < AES_BLOCK_SIZE && nbytes != 0) {

            *(out_arg++) = *(in_arg++) ^ ivp[chunk];

            chunk++, nbytes--;

        }

        EVP_CIPHER_CTX_set_num(ctx, chunk % AES_BLOCK_SIZE);

    }

    if (nbytes == 0)

        return 1;

    memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);

    if ((chunk = nbytes & ~(AES_BLOCK_SIZE - 1))) {

        if (!padlock_ofb_encrypt(out_arg, in_arg, cdata, chunk))

            return 0;

        nbytes -= chunk;

    }

    if (nbytes) {

        unsigned char *ivp = cdata->iv;

        out_arg += chunk;

        in_arg += chunk;

        EVP_CIPHER_CTX_set_num(ctx, (int)nbytes);

        padlock_reload_key(); /* empirically found */

        padlock_aes_block(ivp, ivp, cdata);

        padlock_reload_key(); /* empirically found */

        while (nbytes) {

            *(out_arg++) = *(in_arg++) ^ *ivp;

            ivp++, nbytes--;

        }

    }

    memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);

    return 1;

}

static void padlock_ctr32_encrypt_glue(const unsigned char *in,

    unsigned char *out, size_t blocks,

    struct padlock_cipher_data *ctx,

    const unsigned char *ivec)

{

    memcpy(ctx->iv, ivec, AES_BLOCK_SIZE);

    padlock_ctr32_encrypt(out, in, ctx, AES_BLOCK_SIZE * blocks);

}

static int

padlock_ctr_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,

    const unsigned char *in_arg, size_t nbytes)

{

    struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);

    int n = EVP_CIPHER_CTX_get_num(ctx);

    unsigned int num;

    if (n < 0)

        return 0;

    num = (unsigned int)n;

    CRYPTO_ctr128_encrypt_ctr32(in_arg, out_arg, nbytes,

        cdata, EVP_CIPHER_CTX_iv_noconst(ctx),

        EVP_CIPHER_CTX_buf_noconst(ctx), &num,

        (ctr128_f)padlock_ctr32_encrypt_glue);

    EVP_CIPHER_CTX_set_num(ctx, (size_t)num);

    return 1;

}

#define EVP_CIPHER_block_size_ECB AES_BLOCK_SIZE

#define EVP_CIPHER_block_size_CBC AES_BLOCK_SIZE

#define EVP_CIPHER_block_size_OFB 1

#define EVP_CIPHER_block_size_CFB 1

#define EVP_CIPHER_block_size_CTR 1

/*

 * Declaring so many ciphers by hand would be a pain. Instead introduce a bit

 * of preprocessor magic :-)

 */

#define DECLARE_AES_EVP(ksize, lmode, umode)                                                    \

    static EVP_CIPHER *_hidden_aes_##ksize##_##lmode = NULL;                                    \

    static const EVP_CIPHER *padlock_aes_##ksize##_##lmode(void)                                \

    {                                                                                           \

        if (_hidden_aes_##ksize##_##lmode == NULL                                               \

            && ((_hidden_aes_##ksize##_##lmode = EVP_CIPHER_meth_new(NID_aes_##ksize##_##lmode, \

                     EVP_CIPHER_block_size_##umode,                                             \

                     AES_KEY_SIZE_##ksize))                                                     \

                    == NULL                                                                     \

                || !EVP_CIPHER_meth_set_iv_length(_hidden_aes_##ksize##_##lmode,                \

                    AES_BLOCK_SIZE)                                                             \

                || !EVP_CIPHER_meth_set_flags(_hidden_aes_##ksize##_##lmode,                    \

                    0 | EVP_CIPH_##umode##_MODE)                                                \

                || !EVP_CIPHER_meth_set_init(_hidden_aes_##ksize##_##lmode,                     \

                    padlock_aes_init_key)                                                       \

                || !EVP_CIPHER_meth_set_do_cipher(_hidden_aes_##ksize##_##lmode,                \

                    padlock_##lmode##_cipher)                                                   \

                || !EVP_CIPHER_meth_set_impl_ctx_size(_hidden_aes_##ksize##_##lmode,            \

                    sizeof(struct padlock_cipher_data) + 16)                                    \

                || !EVP_CIPHER_meth_set_set_asn1_params(_hidden_aes_##ksize##_##lmode,          \

                    EVP_CIPHER_set_asn1_iv)                                                     \

                || !EVP_CIPHER_meth_set_get_asn1_params(_hidden_aes_##ksize##_##lmode,          \

                    EVP_CIPHER_get_asn1_iv))) {                                                 \

            EVP_CIPHER_meth_free(_hidden_aes_##ksize##_##lmode);                                \

            _hidden_aes_##ksize##_##lmode = NULL;                                               \

        }                                                                                       \

        return _hidden_aes_##ksize##_##lmode;                                                   \

    }

DECLARE_AES_EVP(128, ecb, ECB)

DECLARE_AES_EVP(128, cbc, CBC)

DECLARE_AES_EVP(128, cfb, CFB)

DECLARE_AES_EVP(128, ofb, OFB)

DECLARE_AES_EVP(128, ctr, CTR)

DECLARE_AES_EVP(192, ecb, ECB)

DECLARE_AES_EVP(192, cbc, CBC)

DECLARE_AES_EVP(192, cfb, CFB)

DECLARE_AES_EVP(192, ofb, OFB)

DECLARE_AES_EVP(192, ctr, CTR)

DECLARE_AES_EVP(256, ecb, ECB)

DECLARE_AES_EVP(256, cbc, CBC)

DECLARE_AES_EVP(256, cfb, CFB)

DECLARE_AES_EVP(256, ofb, OFB)

DECLARE_AES_EVP(256, ctr, CTR)

static int

padlock_ciphers(ENGINE *e, const EVP_CIPHER **cipher, const int **nids,

    int nid)

{

    /* No specific cipher => return a list of supported nids ... */

    if (!cipher) {

        *nids = padlock_cipher_nids;

        return padlock_cipher_nids_num;

    }

    /* ... or the requested "cipher" otherwise */

    switch (nid) {

    case NID_aes_128_ecb:

        *cipher = padlock_aes_128_ecb();

        break;

    case NID_aes_128_cbc:

        *cipher = padlock_aes_128_cbc();

        break;

    case NID_aes_128_cfb:

        *cipher = padlock_aes_128_cfb();

        break;

    case NID_aes_128_ofb:

        *cipher = padlock_aes_128_ofb();

        break;

    case NID_aes_128_ctr:

        *cipher = padlock_aes_128_ctr();

        break;

    case NID_aes_192_ecb:

        *cipher = padlock_aes_192_ecb();

        break;

    case NID_aes_192_cbc:

        *cipher = padlock_aes_192_cbc();

        break;

    case NID_aes_192_cfb:

        *cipher = padlock_aes_192_cfb();

        break;

    case NID_aes_192_ofb:

        *cipher = padlock_aes_192_ofb();

        break;

    case NID_aes_192_ctr:

        *cipher = padlock_aes_192_ctr();

        break;

    case NID_aes_256_ecb:

        *cipher = padlock_aes_256_ecb();

        break;

    case NID_aes_256_cbc:

        *cipher = padlock_aes_256_cbc();

        break;

    case NID_aes_256_cfb:

        *cipher = padlock_aes_256_cfb();

        break;

    case NID_aes_256_ofb:

        *cipher = padlock_aes_256_ofb();

        break;

    case NID_aes_256_ctr:

        *cipher = padlock_aes_256_ctr();

        break;

    default:

        /* Sorry, we don't support this NID */

        *cipher = NULL;

        return 0;

    }

    return 1;

}

/* Prepare the encryption key for PadLock usage */

static int

padlock_aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,

    const unsigned char *iv, int enc)

{

    struct padlock_cipher_data *cdata;

    int key_len = EVP_CIPHER_CTX_get_key_length(ctx) * 8;

    unsigned long mode = EVP_CIPHER_CTX_get_mode(ctx);

    if (key == NULL)

        return 0; /* ERROR */

    cdata = ALIGNED_CIPHER_DATA(ctx);

    memset(cdata, 0, sizeof(*cdata));

    /* Prepare Control word. */

    if (mode == EVP_CIPH_OFB_MODE || mode == EVP_CIPH_CTR_MODE)

        cdata->cword.b.encdec = 0;

    else

        cdata->cword.b.encdec = (EVP_CIPHER_CTX_is_encrypting(ctx) == 0);

    cdata->cword.b.rounds = 10 + (key_len - 128) / 32;

    cdata->cword.b.ksize = (key_len - 128) / 64;

    switch (key_len) {

    case 128:

        /*

         * PadLock can generate an extended key for AES128 in hardware

         */

        memcpy(cdata->ks.rd_key, key, AES_KEY_SIZE_128);

        cdata->cword.b.keygen = 0;

        break;

    case 192:

    case 256:

        /*

         * Generate an extended AES key in software. Needed for AES192/AES256

         */

        /*

         * Well, the above applies to Stepping 8 CPUs and is listed as

         * hardware errata. They most likely will fix it at some point and

         * then a check for stepping would be due here.

         */

        if ((mode == EVP_CIPH_ECB_MODE || mode == EVP_CIPH_CBC_MODE)

            && !enc)

            AES_set_decrypt_key(key, key_len, &cdata->ks);

        else

            AES_set_encrypt_key(key, key_len, &cdata->ks);

        /*

         * OpenSSL C functions use byte-swapped extended key.

         */

        padlock_key_bswap(&cdata->ks);

        cdata->cword.b.keygen = 1;

        break;

    default:

        /* ERROR */

        return 0;

    }

    /*

     * This is done to cover for cases when user reuses the

     * context for new key. The catch is that if we don't do

     * this, padlock_eas_cipher might proceed with old key...

     */

    padlock_reload_key();

    return 1;

}

/* ===== Random Number Generator ===== */

/*

 * This code is not engaged. The reason is that it does not comply

 * with recommendations for VIA RNG usage for secure applications

 * (posted at http://www.via.com.tw/en/viac3/c3.jsp) nor does it

 * provide meaningful error control...

 */

/*

 * Wrapper that provides an interface between the API and the raw PadLock

 * RNG

 */

static int padlock_rand_bytes(unsigned char *output, int count)

{

    unsigned int eax, buf;

    while (count >= 8) {

        eax = padlock_xstore(output, 0);

        if (!(eax & (1 << 6)))

            return 0; /* RNG disabled */

        /* this ---vv--- covers DC bias, Raw Bits and String Filter */

        if (eax & (0x1F << 10))

            return 0;

        if ((eax & 0x1F) == 0)

            continue; /* no data, retry... */

        if ((eax & 0x1F) != 8)

            return 0; /* fatal failure...  */

        output += 8;

        count -= 8;

    }

    while (count > 0) {

        eax = padlock_xstore(&buf, 3);

        if (!(eax & (1 << 6)))

            return 0; /* RNG disabled */

        /* this ---vv--- covers DC bias, Raw Bits and String Filter */

        if (eax & (0x1F << 10))

            return 0;

        if ((eax & 0x1F) == 0)

            continue; /* no data, retry... */

        if ((eax & 0x1F) != 1)

            return 0; /* fatal failure...  */

        *output++ = (unsigned char)buf;

        count--;

    }

    OPENSSL_cleanse(&buf, sizeof(buf));

    return 1;

}

/* Dummy but necessary function */

static int padlock_rand_status(void)

{

    return 1;

}

/* Prepare structure for registration */

static RAND_METHOD padlock_rand = {

    NULL, /* seed */

    padlock_rand_bytes, /* bytes */

    NULL, /* cleanup */

    NULL, /* add */

    padlock_rand_bytes, /* pseudorand */

    padlock_rand_status, /* rand status */

};

#endif /* COMPILE_PADLOCKENG */

#endif /* !OPENSSL_NO_PADLOCKENG */

#if defined(OPENSSL_NO_PADLOCKENG) || !defined(COMPILE_PADLOCKENG)

#ifndef OPENSSL_NO_DYNAMIC_ENGINE

OPENSSL_EXPORT

int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns);

OPENSSL_EXPORT

int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns)

{

    return 0;

}

IMPLEMENT_DYNAMIC_CHECK_FN()

#endif

#endif