/*

 * Copyright 2005-2019 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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

 */

/*

 * Support for PVK format keys and related structures (such a PUBLICKEYBLOB

 * and PRIVATEKEYBLOB).

 */

#include "internal/cryptlib.h"

#include <openssl/pem.h>

#include <openssl/rand.h>

#include <openssl/bn.h>

#if !defined(OPENSSL_NO_RSA) && !defined(OPENSSL_NO_DSA)

# include <openssl/dsa.h>

# include <openssl/rsa.h>

/*

 * Utility function: read a DWORD (4 byte unsigned integer) in little endian

 * format

 */

static unsigned int read_ledword(const unsigned char **in)

{

    const unsigned char *p = *in;

    unsigned int ret;

    ret = *p++;

    ret |= (*p++ << 8);

    ret |= (*p++ << 16);

    ret |= (*p++ << 24);

    *in = p;

    return ret;

}

/*

 * Read a BIGNUM in little endian format. The docs say that this should take

 * up bitlen/8 bytes.

 */

static int read_lebn(const unsigned char **in, unsigned int nbyte, BIGNUM **r)

{

    *r = BN_lebin2bn(*in, nbyte, NULL);

    if (*r == NULL)

        return 0;

    *in += nbyte;

    return 1;

}

/* Convert private key blob to EVP_PKEY: RSA and DSA keys supported */

# define MS_PUBLICKEYBLOB        0x6

# define MS_PRIVATEKEYBLOB       0x7

# define MS_RSA1MAGIC            0x31415352L

# define MS_RSA2MAGIC            0x32415352L

# define MS_DSS1MAGIC            0x31535344L

# define MS_DSS2MAGIC            0x32535344L

# define MS_KEYALG_RSA_KEYX      0xa400

# define MS_KEYALG_DSS_SIGN      0x2200

# define MS_KEYTYPE_KEYX         0x1

# define MS_KEYTYPE_SIGN         0x2

/* Maximum length of a blob after header */

# define BLOB_MAX_LENGTH          102400

/* The PVK file magic number: seems to spell out "bobsfile", who is Bob? */

# define MS_PVKMAGIC             0xb0b5f11eL

/* Salt length for PVK files */

# define PVK_SALTLEN             0x10

/* Maximum length in PVK header */

# define PVK_MAX_KEYLEN          102400

/* Maximum salt length */

# define PVK_MAX_SALTLEN         10240

static EVP_PKEY *b2i_rsa(const unsigned char **in,

                         unsigned int bitlen, int ispub);

static EVP_PKEY *b2i_dss(const unsigned char **in,

                         unsigned int bitlen, int ispub);

static int do_blob_header(const unsigned char **in, unsigned int length,

                          unsigned int *pmagic, unsigned int *pbitlen,

                          int *pisdss, int *pispub)

{

    const unsigned char *p = *in;

    if (length < 16)

        return 0;

    /* bType */

    if (*p == MS_PUBLICKEYBLOB) {

        if (*pispub == 0) {

            PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);

            return 0;

        }

        *pispub = 1;

    } else if (*p == MS_PRIVATEKEYBLOB) {

        if (*pispub == 1) {

            PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);

            return 0;

        }

        *pispub = 0;

    } else

        return 0;

    p++;

    /* Version */

    if (*p++ != 0x2) {

        PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_VERSION_NUMBER);

        return 0;

    }

    /* Ignore reserved, aiKeyAlg */

    p += 6;

    *pmagic = read_ledword(&p);

    *pbitlen = read_ledword(&p);

    *pisdss = 0;

    switch (*pmagic) {

    case MS_DSS1MAGIC:

        *pisdss = 1;

        /* fall thru */

    case MS_RSA1MAGIC:

        if (*pispub == 0) {

            PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PRIVATE_KEY_BLOB);

            return 0;

        }

        break;

    case MS_DSS2MAGIC:

        *pisdss = 1;

        /* fall thru */

    case MS_RSA2MAGIC:

        if (*pispub == 1) {

            PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_EXPECTING_PUBLIC_KEY_BLOB);

            return 0;

        }

        break;

    default:

        PEMerr(PEM_F_DO_BLOB_HEADER, PEM_R_BAD_MAGIC_NUMBER);

        return -1;

    }

    *in = p;

    return 1;

}

static unsigned int blob_length(unsigned bitlen, int isdss, int ispub)

{

    unsigned int nbyte, hnbyte;

    nbyte = (bitlen + 7) >> 3;

    hnbyte = (bitlen + 15) >> 4;

    if (isdss) {

        /*

         * Expected length: 20 for q + 3 components bitlen each + 24 for seed

         * structure.

         */

        if (ispub)

            return 44 + 3 * nbyte;

        /*

         * Expected length: 20 for q, priv, 2 bitlen components + 24 for seed

         * structure.

         */

        else

            return 64 + 2 * nbyte;

    } else {

        /* Expected length: 4 for 'e' + 'n' */

        if (ispub)

            return 4 + nbyte;

        else

            /*

             * Expected length: 4 for 'e' and 7 other components. 2

             * components are bitlen size, 5 are bitlen/2

             */

            return 4 + 2 * nbyte + 5 * hnbyte;

    }

}

static EVP_PKEY *do_b2i(const unsigned char **in, unsigned int length,

                        int ispub)

{

    const unsigned char *p = *in;

    unsigned int bitlen, magic;

    int isdss;

    if (do_blob_header(&p, length, &magic, &bitlen, &isdss, &ispub) <= 0) {

        PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_HEADER_PARSE_ERROR);

        return NULL;

    }

    length -= 16;

    if (length < blob_length(bitlen, isdss, ispub)) {

        PEMerr(PEM_F_DO_B2I, PEM_R_KEYBLOB_TOO_SHORT);

        return NULL;

    }

    if (isdss)

        return b2i_dss(&p, bitlen, ispub);

    else

        return b2i_rsa(&p, bitlen, ispub);

}

static EVP_PKEY *do_b2i_bio(BIO *in, int ispub)

{

    const unsigned char *p;

    unsigned char hdr_buf[16], *buf = NULL;

    unsigned int bitlen, magic, length;

    int isdss;

    EVP_PKEY *ret = NULL;

    if (BIO_read(in, hdr_buf, 16) != 16) {

        PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);

        return NULL;

    }

    p = hdr_buf;

    if (do_blob_header(&p, 16, &magic, &bitlen, &isdss, &ispub) <= 0)

        return NULL;

    length = blob_length(bitlen, isdss, ispub);

    if (length > BLOB_MAX_LENGTH) {

        PEMerr(PEM_F_DO_B2I_BIO, PEM_R_HEADER_TOO_LONG);

        return NULL;

    }

    buf = OPENSSL_malloc(length);

    if (buf == NULL) {

        PEMerr(PEM_F_DO_B2I_BIO, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    p = buf;

    if (BIO_read(in, buf, length) != (int)length) {

        PEMerr(PEM_F_DO_B2I_BIO, PEM_R_KEYBLOB_TOO_SHORT);

        goto err;

    }

    if (isdss)

        ret = b2i_dss(&p, bitlen, ispub);

    else

        ret = b2i_rsa(&p, bitlen, ispub);

 err:

    OPENSSL_free(buf);

    return ret;

}

static EVP_PKEY *b2i_dss(const unsigned char **in,

                         unsigned int bitlen, int ispub)

{

    const unsigned char *p = *in;

    EVP_PKEY *ret = NULL;

    DSA *dsa = NULL;

    BN_CTX *ctx = NULL;

    unsigned int nbyte;

    BIGNUM *pbn = NULL, *qbn = NULL, *gbn = NULL, *priv_key = NULL;

    BIGNUM *pub_key = NULL;

    nbyte = (bitlen + 7) >> 3;

    dsa = DSA_new();

    ret = EVP_PKEY_new();

    if (dsa == NULL || ret == NULL)

        goto memerr;

    if (!read_lebn(&p, nbyte, &pbn))

        goto memerr;

    if (!read_lebn(&p, 20, &qbn))

        goto memerr;

    if (!read_lebn(&p, nbyte, &gbn))

        goto memerr;

    if (ispub) {

        if (!read_lebn(&p, nbyte, &pub_key))

            goto memerr;

    } else {

        if (!read_lebn(&p, 20, &priv_key))

            goto memerr;

        /* Set constant time flag before public key calculation */

        BN_set_flags(priv_key, BN_FLG_CONSTTIME);

        /* Calculate public key */

        pub_key = BN_new();

        if (pub_key == NULL)

            goto memerr;

        if ((ctx = BN_CTX_new()) == NULL)

            goto memerr;

        if (!BN_mod_exp(pub_key, gbn, priv_key, pbn, ctx))

            goto memerr;

        BN_CTX_free(ctx);

        ctx = NULL;

    }

    if (!DSA_set0_pqg(dsa, pbn, qbn, gbn))

        goto memerr;

    pbn = qbn = gbn = NULL;

    if (!DSA_set0_key(dsa, pub_key, priv_key))

        goto memerr;

    pub_key = priv_key = NULL;

    if (!EVP_PKEY_set1_DSA(ret, dsa))

        goto memerr;

    DSA_free(dsa);

    *in = p;

    return ret;

 memerr:

    PEMerr(PEM_F_B2I_DSS, ERR_R_MALLOC_FAILURE);

    DSA_free(dsa);

    BN_free(pbn);

    BN_free(qbn);

    BN_free(gbn);

    BN_free(pub_key);

    BN_free(priv_key);

    EVP_PKEY_free(ret);

    BN_CTX_free(ctx);

    return NULL;

}

static EVP_PKEY *b2i_rsa(const unsigned char **in,

                         unsigned int bitlen, int ispub)

{

    const unsigned char *pin = *in;

    EVP_PKEY *ret = NULL;

    BIGNUM *e = NULL, *n = NULL, *d = NULL;

    BIGNUM *p = NULL, *q = NULL, *dmp1 = NULL, *dmq1 = NULL, *iqmp = NULL;

    RSA *rsa = NULL;

    unsigned int nbyte, hnbyte;

    nbyte = (bitlen + 7) >> 3;

    hnbyte = (bitlen + 15) >> 4;

    rsa = RSA_new();

    ret = EVP_PKEY_new();

    if (rsa == NULL || ret == NULL)

        goto memerr;

    e = BN_new();

    if (e == NULL)

        goto memerr;

    if (!BN_set_word(e, read_ledword(&pin)))

        goto memerr;

    if (!read_lebn(&pin, nbyte, &n))

        goto memerr;

    if (!ispub) {

        if (!read_lebn(&pin, hnbyte, &p))

            goto memerr;

        if (!read_lebn(&pin, hnbyte, &q))

            goto memerr;

        if (!read_lebn(&pin, hnbyte, &dmp1))

            goto memerr;

        if (!read_lebn(&pin, hnbyte, &dmq1))

            goto memerr;

        if (!read_lebn(&pin, hnbyte, &iqmp))

            goto memerr;

        if (!read_lebn(&pin, nbyte, &d))

            goto memerr;

        if (!RSA_set0_factors(rsa, p, q))

            goto memerr;

        p = q = NULL;

        if (!RSA_set0_crt_params(rsa, dmp1, dmq1, iqmp))

            goto memerr;

        dmp1 = dmq1 = iqmp = NULL;

    }

    if (!RSA_set0_key(rsa, n, e, d))

        goto memerr;

    n = e = d = NULL;

    if (!EVP_PKEY_set1_RSA(ret, rsa))

        goto memerr;

    RSA_free(rsa);

    *in = pin;

    return ret;

 memerr:

    PEMerr(PEM_F_B2I_RSA, ERR_R_MALLOC_FAILURE);

    BN_free(e);

    BN_free(n);

    BN_free(p);

    BN_free(q);

    BN_free(dmp1);

    BN_free(dmq1);

    BN_free(iqmp);

    BN_free(d);

    RSA_free(rsa);

    EVP_PKEY_free(ret);

    return NULL;

}

EVP_PKEY *b2i_PrivateKey(const unsigned char **in, long length)

{

    return do_b2i(in, length, 0);

}

EVP_PKEY *b2i_PublicKey(const unsigned char **in, long length)

{

    return do_b2i(in, length, 1);

}

EVP_PKEY *b2i_PrivateKey_bio(BIO *in)

{

    return do_b2i_bio(in, 0);

}

EVP_PKEY *b2i_PublicKey_bio(BIO *in)

{

    return do_b2i_bio(in, 1);

}

static void write_ledword(unsigned char **out, unsigned int dw)

{

    unsigned char *p = *out;

    *p++ = dw & 0xff;

    *p++ = (dw >> 8) & 0xff;

    *p++ = (dw >> 16) & 0xff;

    *p++ = (dw >> 24) & 0xff;

    *out = p;

}

static void write_lebn(unsigned char **out, const BIGNUM *bn, int len)

{

    BN_bn2lebinpad(bn, *out, len);

    *out += len;

}

static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *magic);

static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *magic);

static void write_rsa(unsigned char **out, RSA *rsa, int ispub);

static void write_dsa(unsigned char **out, DSA *dsa, int ispub);

static int do_i2b(unsigned char **out, EVP_PKEY *pk, int ispub)

{

    unsigned char *p;

    unsigned int bitlen, magic = 0, keyalg;

    int outlen, noinc = 0;

    int pktype = EVP_PKEY_id(pk);

    if (pktype == EVP_PKEY_DSA) {

        bitlen = check_bitlen_dsa(EVP_PKEY_get0_DSA(pk), ispub, &magic);

        keyalg = MS_KEYALG_DSS_SIGN;

    } else if (pktype == EVP_PKEY_RSA) {

        bitlen = check_bitlen_rsa(EVP_PKEY_get0_RSA(pk), ispub, &magic);

        keyalg = MS_KEYALG_RSA_KEYX;

    } else

        return -1;

    if (bitlen == 0)

        return -1;

    outlen = 16 + blob_length(bitlen,

                              keyalg == MS_KEYALG_DSS_SIGN ? 1 : 0, ispub);

    if (out == NULL)

        return outlen;

    if (*out)

        p = *out;

    else {

        if ((p = OPENSSL_malloc(outlen)) == NULL) {

            PEMerr(PEM_F_DO_I2B, ERR_R_MALLOC_FAILURE);

            return -1;

        }

        *out = p;

        noinc = 1;

    }

    if (ispub)

        *p++ = MS_PUBLICKEYBLOB;

    else

        *p++ = MS_PRIVATEKEYBLOB;

    *p++ = 0x2;

    *p++ = 0;

    *p++ = 0;

    write_ledword(&p, keyalg);

    write_ledword(&p, magic);

    write_ledword(&p, bitlen);

    if (keyalg == MS_KEYALG_DSS_SIGN)

        write_dsa(&p, EVP_PKEY_get0_DSA(pk), ispub);

    else

        write_rsa(&p, EVP_PKEY_get0_RSA(pk), ispub);

    if (!noinc)

        *out += outlen;

    return outlen;

}

static int do_i2b_bio(BIO *out, EVP_PKEY *pk, int ispub)

{

    unsigned char *tmp = NULL;

    int outlen, wrlen;

    outlen = do_i2b(&tmp, pk, ispub);

    if (outlen < 0)

        return -1;

    wrlen = BIO_write(out, tmp, outlen);

    OPENSSL_free(tmp);

    if (wrlen == outlen)

        return outlen;

    return -1;

}

static int check_bitlen_dsa(DSA *dsa, int ispub, unsigned int *pmagic)

{

    int bitlen;

    const BIGNUM *p = NULL, *q = NULL, *g = NULL;

    const BIGNUM *pub_key = NULL, *priv_key = NULL;

    DSA_get0_pqg(dsa, &p, &q, &g);

    DSA_get0_key(dsa, &pub_key, &priv_key);

    bitlen = BN_num_bits(p);

    if ((bitlen & 7) || (BN_num_bits(q) != 160)

        || (BN_num_bits(g) > bitlen))

        goto badkey;

    if (ispub) {

        if (BN_num_bits(pub_key) > bitlen)

            goto badkey;

        *pmagic = MS_DSS1MAGIC;

    } else {

        if (BN_num_bits(priv_key) > 160)

            goto badkey;

        *pmagic = MS_DSS2MAGIC;

    }

    return bitlen;

 badkey:

    PEMerr(PEM_F_CHECK_BITLEN_DSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);

    return 0;

}

static int check_bitlen_rsa(RSA *rsa, int ispub, unsigned int *pmagic)

{

    int nbyte, hnbyte, bitlen;

    const BIGNUM *e;

    RSA_get0_key(rsa, NULL, &e, NULL);

    if (BN_num_bits(e) > 32)

        goto badkey;

    bitlen = RSA_bits(rsa);

    nbyte = RSA_size(rsa);

    hnbyte = (bitlen + 15) >> 4;

    if (ispub) {

        *pmagic = MS_RSA1MAGIC;

        return bitlen;

    } else {

        const BIGNUM *d, *p, *q, *iqmp, *dmp1, *dmq1;

        *pmagic = MS_RSA2MAGIC;

        /*

         * For private key each component must fit within nbyte or hnbyte.

         */

        RSA_get0_key(rsa, NULL, NULL, &d);

        if (BN_num_bytes(d) > nbyte)

            goto badkey;

        RSA_get0_factors(rsa, &p, &q);

        RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);

        if ((BN_num_bytes(iqmp) > hnbyte)

            || (BN_num_bytes(p) > hnbyte)

            || (BN_num_bytes(q) > hnbyte)

            || (BN_num_bytes(dmp1) > hnbyte)

            || (BN_num_bytes(dmq1) > hnbyte))

            goto badkey;

    }

    return bitlen;

 badkey:

    PEMerr(PEM_F_CHECK_BITLEN_RSA, PEM_R_UNSUPPORTED_KEY_COMPONENTS);

    return 0;

}

static void write_rsa(unsigned char **out, RSA *rsa, int ispub)

{

    int nbyte, hnbyte;

    const BIGNUM *n, *d, *e, *p, *q, *iqmp, *dmp1, *dmq1;

    nbyte = RSA_size(rsa);

    hnbyte = (RSA_bits(rsa) + 15) >> 4;

    RSA_get0_key(rsa, &n, &e, &d);

    write_lebn(out, e, 4);

    write_lebn(out, n, nbyte);

    if (ispub)

        return;

    RSA_get0_factors(rsa, &p, &q);

    RSA_get0_crt_params(rsa, &dmp1, &dmq1, &iqmp);

    write_lebn(out, p, hnbyte);

    write_lebn(out, q, hnbyte);

    write_lebn(out, dmp1, hnbyte);

    write_lebn(out, dmq1, hnbyte);

    write_lebn(out, iqmp, hnbyte);

    write_lebn(out, d, nbyte);

}

static void write_dsa(unsigned char **out, DSA *dsa, int ispub)

{

    int nbyte;

    const BIGNUM *p = NULL, *q = NULL, *g = NULL;

    const BIGNUM *pub_key = NULL, *priv_key = NULL;

    DSA_get0_pqg(dsa, &p, &q, &g);

    DSA_get0_key(dsa, &pub_key, &priv_key);

    nbyte = BN_num_bytes(p);

    write_lebn(out, p, nbyte);

    write_lebn(out, q, 20);

    write_lebn(out, g, nbyte);

    if (ispub)

        write_lebn(out, pub_key, nbyte);

    else

        write_lebn(out, priv_key, 20);

    /* Set "invalid" for seed structure values */

    memset(*out, 0xff, 24);

    *out += 24;

    return;

}

int i2b_PrivateKey_bio(BIO *out, EVP_PKEY *pk)

{

    return do_i2b_bio(out, pk, 0);

}

int i2b_PublicKey_bio(BIO *out, EVP_PKEY *pk)

{

    return do_i2b_bio(out, pk, 1);

}

# ifndef OPENSSL_NO_RC4

static int do_PVK_header(const unsigned char **in, unsigned int length,

                         int skip_magic,

                         unsigned int *psaltlen, unsigned int *pkeylen)

{

    const unsigned char *p = *in;

    unsigned int pvk_magic, is_encrypted;

    if (skip_magic) {

        if (length < 20) {

            PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);

            return 0;

        }

    } else {

        if (length < 24) {

            PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);

            return 0;

        }

        pvk_magic = read_ledword(&p);

        if (pvk_magic != MS_PVKMAGIC) {

            PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_BAD_MAGIC_NUMBER);

            return 0;

        }

    }

    /* Skip reserved */

    p += 4;

    /*

     * keytype =

     */ read_ledword(&p);

    is_encrypted = read_ledword(&p);

    *psaltlen = read_ledword(&p);

    *pkeylen = read_ledword(&p);

    if (*pkeylen > PVK_MAX_KEYLEN || *psaltlen > PVK_MAX_SALTLEN)

        return 0;

    if (is_encrypted && !*psaltlen) {

        PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_INCONSISTENT_HEADER);

        return 0;

    }

    *in = p;

    return 1;

}

static int derive_pvk_key(unsigned char *key,

                          const unsigned char *salt, unsigned int saltlen,

                          const unsigned char *pass, int passlen)

{

    EVP_MD_CTX *mctx = EVP_MD_CTX_new();

    int rv = 1;

    if (mctx == NULL

        || !EVP_DigestInit_ex(mctx, EVP_sha1(), NULL)

        || !EVP_DigestUpdate(mctx, salt, saltlen)

        || !EVP_DigestUpdate(mctx, pass, passlen)

        || !EVP_DigestFinal_ex(mctx, key, NULL))

        rv = 0;

    EVP_MD_CTX_free(mctx);

    return rv;

}

static EVP_PKEY *do_PVK_body(const unsigned char **in,

                             unsigned int saltlen, unsigned int keylen,

                             pem_password_cb *cb, void *u)

{

    EVP_PKEY *ret = NULL;

    const unsigned char *p = *in;

    unsigned int magic;

    unsigned char *enctmp = NULL, *q;

    unsigned char keybuf[20];

    EVP_CIPHER_CTX *cctx = EVP_CIPHER_CTX_new();

    if (saltlen) {

        char psbuf[PEM_BUFSIZE];

        int enctmplen, inlen;

        if (cb)

            inlen = cb(psbuf, PEM_BUFSIZE, 0, u);

        else

            inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);

        if (inlen < 0) {

            PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_PASSWORD_READ);

            goto err;

        }

        enctmp = OPENSSL_malloc(keylen + 8);

        if (enctmp == NULL) {

            PEMerr(PEM_F_DO_PVK_BODY, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        if (!derive_pvk_key(keybuf, p, saltlen,

                            (unsigned char *)psbuf, inlen))

            goto err;

        p += saltlen;

        /* Copy BLOBHEADER across, decrypt rest */

        memcpy(enctmp, p, 8);

        p += 8;

        if (keylen < 8) {

            PEMerr(PEM_F_DO_PVK_BODY, PEM_R_PVK_TOO_SHORT);

            goto err;

        }

        inlen = keylen - 8;

        q = enctmp + 8;

        if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))

            goto err;

        if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))

            goto err;

        if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))

            goto err;

        magic = read_ledword((const unsigned char **)&q);

        if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {

            q = enctmp + 8;

            memset(keybuf + 5, 0, 11);

            if (!EVP_DecryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))

                goto err;

            if (!EVP_DecryptUpdate(cctx, q, &enctmplen, p, inlen))

                goto err;

            if (!EVP_DecryptFinal_ex(cctx, q + enctmplen, &enctmplen))

                goto err;

            magic = read_ledword((const unsigned char **)&q);

            if (magic != MS_RSA2MAGIC && magic != MS_DSS2MAGIC) {

                PEMerr(PEM_F_DO_PVK_BODY, PEM_R_BAD_DECRYPT);

                goto err;

            }

        }

        p = enctmp;

    }

    ret = b2i_PrivateKey(&p, keylen);

 err:

    EVP_CIPHER_CTX_free(cctx);

    if (enctmp != NULL) {

        OPENSSL_cleanse(keybuf, sizeof(keybuf));

        OPENSSL_free(enctmp);

    }

    return ret;

}

EVP_PKEY *b2i_PVK_bio(BIO *in, pem_password_cb *cb, void *u)

{

    unsigned char pvk_hdr[24], *buf = NULL;

    const unsigned char *p;

    int buflen;

    EVP_PKEY *ret = NULL;

    unsigned int saltlen, keylen;

    if (BIO_read(in, pvk_hdr, 24) != 24) {

        PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);

        return NULL;

    }

    p = pvk_hdr;

    if (!do_PVK_header(&p, 24, 0, &saltlen, &keylen))

        return 0;

    buflen = (int)keylen + saltlen;

    buf = OPENSSL_malloc(buflen);

    if (buf == NULL) {

        PEMerr(PEM_F_B2I_PVK_BIO, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    p = buf;

    if (BIO_read(in, buf, buflen) != buflen) {

        PEMerr(PEM_F_B2I_PVK_BIO, PEM_R_PVK_DATA_TOO_SHORT);

        goto err;

    }

    ret = do_PVK_body(&p, saltlen, keylen, cb, u);

 err:

    OPENSSL_clear_free(buf, buflen);

    return ret;

}

static int i2b_PVK(unsigned char **out, EVP_PKEY *pk, int enclevel,

                   pem_password_cb *cb, void *u)

{

    int outlen = 24, pklen;

    unsigned char *p = NULL, *start = NULL, *salt = NULL;

    EVP_CIPHER_CTX *cctx = NULL;

    if (enclevel)

        outlen += PVK_SALTLEN;

    pklen = do_i2b(NULL, pk, 0);

    if (pklen < 0)

        return -1;

    outlen += pklen;

    if (out == NULL)

        return outlen;

    if (*out != NULL) {

        p = *out;

    } else {

        start = p = OPENSSL_malloc(outlen);

        if (p == NULL) {

            PEMerr(PEM_F_I2B_PVK, ERR_R_MALLOC_FAILURE);

            return -1;

        }

    }

    cctx = EVP_CIPHER_CTX_new();

    if (cctx == NULL)

        goto error;

    write_ledword(&p, MS_PVKMAGIC);

    write_ledword(&p, 0);

    if (EVP_PKEY_id(pk) == EVP_PKEY_DSA)

        write_ledword(&p, MS_KEYTYPE_SIGN);

    else

        write_ledword(&p, MS_KEYTYPE_KEYX);

    write_ledword(&p, enclevel ? 1 : 0);

    write_ledword(&p, enclevel ? PVK_SALTLEN : 0);

    write_ledword(&p, pklen);

    if (enclevel) {

        if (RAND_bytes(p, PVK_SALTLEN) <= 0)

            goto error;

        salt = p;

        p += PVK_SALTLEN;

    }

    do_i2b(&p, pk, 0);

    if (enclevel != 0) {

        char psbuf[PEM_BUFSIZE];

        unsigned char keybuf[20];

        int enctmplen, inlen;

        if (cb)

            inlen = cb(psbuf, PEM_BUFSIZE, 1, u);

        else

            inlen = PEM_def_callback(psbuf, PEM_BUFSIZE, 1, u);

        if (inlen <= 0) {

            PEMerr(PEM_F_I2B_PVK, PEM_R_BAD_PASSWORD_READ);

            goto error;

        }

        if (!derive_pvk_key(keybuf, salt, PVK_SALTLEN,

                            (unsigned char *)psbuf, inlen))

            goto error;

        if (enclevel == 1)

            memset(keybuf + 5, 0, 11);

        p = salt + PVK_SALTLEN + 8;

        if (!EVP_EncryptInit_ex(cctx, EVP_rc4(), NULL, keybuf, NULL))

            goto error;

        OPENSSL_cleanse(keybuf, 20);

        if (!EVP_EncryptUpdate(cctx, p, &enctmplen, p, pklen - 8))

            goto error;

        if (!EVP_EncryptFinal_ex(cctx, p + enctmplen, &enctmplen))

            goto error;

    }

    EVP_CIPHER_CTX_free(cctx);

    if (*out == NULL)

        *out = start;

    return outlen;

 error:

    EVP_CIPHER_CTX_free(cctx);

    if (*out == NULL)

        OPENSSL_free(start);

    return -1;

}

int i2b_PVK_bio(BIO *out, EVP_PKEY *pk, int enclevel,

                pem_password_cb *cb, void *u)

{

    unsigned char *tmp = NULL;

    int outlen, wrlen;

    outlen = i2b_PVK(&tmp, pk, enclevel, cb, u);

    if (outlen < 0)

        return -1;

    wrlen = BIO_write(out, tmp, outlen);

    OPENSSL_free(tmp);

    if (wrlen == outlen) {

        PEMerr(PEM_F_I2B_PVK_BIO, PEM_R_BIO_WRITE_FAILURE);

        return outlen;

    }