Fix buffer overrun in RSA signing

[thirdparty/openssl.git] / crypto / pem / pvkfmt.c

/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
 * 2005.
 */
/* ====================================================================
 * Copyright (c) 2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

/*
 * Support for PVK format keys and related structures (such a PUBLICKEYBLOB
 * and PRIVATEKEYBLOB).
 */

#include "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)
{
    const unsigned char *p;
    unsigned char *tmpbuf, *q;
    unsigned int i;
    p = *in + nbyte - 1;
    tmpbuf = OPENSSL_malloc(nbyte);
    if (!tmpbuf)
        return 0;
    q = tmpbuf;
    for (i = 0; i < nbyte; i++)
        *q++ = *p--;
    *r = BN_bin2bn(tmpbuf, nbyte, NULL);
    OPENSSL_free(tmpbuf);
    if (*r) {
        *in += nbyte;
        return 1;
    } else
        return 0;
}

/* 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

/* 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

static EVP_PKEY *b2i_rsa(const unsigned char **in, unsigned int length,
                         unsigned int bitlen, int ispub);
static EVP_PKEY *b2i_dss(const unsigned char **in, unsigned int length,
                         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;
    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;
    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, length, bitlen, ispub);
    else
        return b2i_rsa(&p, length, 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);
    buf = OPENSSL_malloc(length);
    if (!buf) {
        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, length, bitlen, ispub);
    else
        ret = b2i_rsa(&p, length, bitlen, ispub);

 err:
    if (buf)
        OPENSSL_free(buf);
    return ret;
}

static EVP_PKEY *b2i_dss(const unsigned char **in, unsigned int length,
                         unsigned int bitlen, int ispub)
{
    const unsigned char *p = *in;
    EVP_PKEY *ret = NULL;
    DSA *dsa = NULL;
    BN_CTX *ctx = NULL;
    unsigned int nbyte;
    nbyte = (bitlen + 7) >> 3;

    dsa = DSA_new();
    ret = EVP_PKEY_new();
    if (!dsa || !ret)
        goto memerr;
    if (!read_lebn(&p, nbyte, &dsa->p))
        goto memerr;
    if (!read_lebn(&p, 20, &dsa->q))
        goto memerr;
    if (!read_lebn(&p, nbyte, &dsa->g))
        goto memerr;
    if (ispub) {
        if (!read_lebn(&p, nbyte, &dsa->pub_key))
            goto memerr;
    } else {
        if (!read_lebn(&p, 20, &dsa->priv_key))
            goto memerr;
        /* Calculate public key */
        if (!(dsa->pub_key = BN_new()))
            goto memerr;
        if (!(ctx = BN_CTX_new()))
            goto memerr;

        if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx))

            goto memerr;
        BN_CTX_free(ctx);
    }

    EVP_PKEY_set1_DSA(ret, dsa);
    DSA_free(dsa);
    *in = p;
    return ret;

 memerr:
    PEMerr(PEM_F_B2I_DSS, ERR_R_MALLOC_FAILURE);
    DSA_free(dsa);
    EVP_PKEY_free(ret);
    if (ctx)
        BN_CTX_free(ctx);
    return NULL;
}

static EVP_PKEY *b2i_rsa(const unsigned char **in, unsigned int length,
                         unsigned int bitlen, int ispub)
{
    const unsigned char *p = *in;
    EVP_PKEY *ret = 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 || !ret)
        goto memerr;
    rsa->e = BN_new();
    if (!rsa->e)
        goto memerr;
    if (!BN_set_word(rsa->e, read_ledword(&p)))
        goto memerr;
    if (!read_lebn(&p, nbyte, &rsa->n))
        goto memerr;
    if (!ispub) {
        if (!read_lebn(&p, hnbyte, &rsa->p))
            goto memerr;
        if (!read_lebn(&p, hnbyte, &rsa->q))
            goto memerr;
        if (!read_lebn(&p, hnbyte, &rsa->dmp1))
            goto memerr;
        if (!read_lebn(&p, hnbyte, &rsa->dmq1))
            goto memerr;
        if (!read_lebn(&p, hnbyte, &rsa->iqmp))
            goto memerr;
        if (!read_lebn(&p, nbyte, &rsa->d))
            goto memerr;
    }

    EVP_PKEY_set1_RSA(ret, rsa);
    RSA_free(rsa);
    *in = p;
    return ret;
 memerr:
    PEMerr(PEM_F_B2I_RSA, ERR_R_MALLOC_FAILURE);
    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)
{
    int nb, i;
    unsigned char *p = *out, *q, c;
    nb = BN_num_bytes(bn);
    BN_bn2bin(bn, p);
    q = p + nb - 1;
    /* In place byte order reversal */
    for (i = 0; i < nb / 2; i++) {
        c = *p;
        *p++ = *q;
        *q-- = c;
    }
    *out += nb;
    /* Pad with zeroes if we have to */
    if (len > 0) {
        len -= nb;
        if (len > 0) {
            memset(*out, 0, 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;
    if (pk->type == EVP_PKEY_DSA) {
        bitlen = check_bitlen_dsa(pk->pkey.dsa, ispub, &magic);
        keyalg = MS_KEYALG_DSS_SIGN;
    } else if (pk->type == EVP_PKEY_RSA) {
        bitlen = check_bitlen_rsa(pk->pkey.rsa, 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 {
        p = OPENSSL_malloc(outlen);
        if (!p)
            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, pk->pkey.dsa, ispub);
    else
        write_rsa(&p, pk->pkey.rsa, 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;
    bitlen = BN_num_bits(dsa->p);
    if ((bitlen & 7) || (BN_num_bits(dsa->q) != 160)
        || (BN_num_bits(dsa->g) > bitlen))
        goto badkey;
    if (ispub) {
        if (BN_num_bits(dsa->pub_key) > bitlen)
            goto badkey;
        *pmagic = MS_DSS1MAGIC;
    } else {
        if (BN_num_bits(dsa->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;
    if (BN_num_bits(rsa->e) > 32)
        goto badkey;
    bitlen = BN_num_bits(rsa->n);
    nbyte = BN_num_bytes(rsa->n);
    hnbyte = (BN_num_bits(rsa->n) + 15) >> 4;
    if (ispub) {
        *pmagic = MS_RSA1MAGIC;
        return bitlen;
    } else {
        *pmagic = MS_RSA2MAGIC;
        /*
         * For private key each component must fit within nbyte or hnbyte.
         */
        if (BN_num_bytes(rsa->d) > nbyte)
            goto badkey;
        if ((BN_num_bytes(rsa->iqmp) > hnbyte)
            || (BN_num_bytes(rsa->p) > hnbyte)
            || (BN_num_bytes(rsa->q) > hnbyte)
            || (BN_num_bytes(rsa->dmp1) > hnbyte)
            || (BN_num_bytes(rsa->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;
    nbyte = BN_num_bytes(rsa->n);
    hnbyte = (BN_num_bits(rsa->n) + 15) >> 4;
    write_lebn(out, rsa->e, 4);
    write_lebn(out, rsa->n, -1);
    if (ispub)
        return;
    write_lebn(out, rsa->p, hnbyte);
    write_lebn(out, rsa->q, hnbyte);
    write_lebn(out, rsa->dmp1, hnbyte);
    write_lebn(out, rsa->dmq1, hnbyte);
    write_lebn(out, rsa->iqmp, hnbyte);
    write_lebn(out, rsa->d, nbyte);
}

static void write_dsa(unsigned char **out, DSA *dsa, int ispub)
{
    int nbyte;
    nbyte = BN_num_bytes(dsa->p);
    write_lebn(out, dsa->p, nbyte);
    write_lebn(out, dsa->q, 20);
    write_lebn(out, dsa->g, nbyte);
    if (ispub)
        write_lebn(out, dsa->pub_key, nbyte);
    else
        write_lebn(out, dsa->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;
        }
        length -= 20;
    } else {
        if (length < 24) {
            PEMerr(PEM_F_DO_PVK_HEADER, PEM_R_PVK_TOO_SHORT);
            return 0;
        }
        length -= 24;
        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 (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;
    int rv = 1;
    EVP_MD_CTX_init(&mctx);
    if (!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_cleanup(&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;
    EVP_CIPHER_CTX cctx;
    EVP_CIPHER_CTX_init(&cctx);
    if (saltlen) {
        char psbuf[PEM_BUFSIZE];
        unsigned char keybuf[20];
        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);
            return NULL;
        }
        enctmp = OPENSSL_malloc(keylen + 8);
        if (!enctmp) {
            PEMerr(PEM_F_DO_PVK_BODY, ERR_R_MALLOC_FAILURE);
            return NULL;
        }
        if (!derive_pvk_key(keybuf, p, saltlen,
                            (unsigned char *)psbuf, inlen))
            return NULL;
        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);
            return NULL;
        }
        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;
            OPENSSL_cleanse(keybuf, 20);
            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;
            }
        } else
            OPENSSL_cleanse(keybuf, 20);
        p = enctmp;
    }

    ret = b2i_PrivateKey(&p, keylen);
 err:
    EVP_CIPHER_CTX_cleanup(&cctx);
    if (enctmp && saltlen)
        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) {
        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, *salt = NULL;
    EVP_CIPHER_CTX cctx;
    EVP_CIPHER_CTX_init(&cctx);
    if (enclevel)
        outlen += PVK_SALTLEN;
    pklen = do_i2b(NULL, pk, 0);
    if (pklen < 0)
        return -1;
    outlen += pklen;
    if (!out)
        return outlen;
    if (*out)
        p = *out;
    else {
        p = OPENSSL_malloc(outlen);
        if (!p) {
            PEMerr(PEM_F_I2B_PVK, ERR_R_MALLOC_FAILURE);
            return -1;
        }
        *out = p;
    }

    write_ledword(&p, MS_PVKMAGIC);
    write_ledword(&p, 0);
    if (pk->type == 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)
        return outlen;
    else {
        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_DecryptUpdate(&cctx, p, &enctmplen, p, pklen - 8))
            goto error;
        if (!EVP_DecryptFinal_ex(&cctx, p + enctmplen, &enctmplen))
            goto error;
    }
    EVP_CIPHER_CTX_cleanup(&cctx);
    return outlen;

 error:
    EVP_CIPHER_CTX_cleanup(&cctx);
    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;
    }
    return -1;
}

# endif

#endif