xref: /freebsd-9.3-release/crypto/openssl/ssl/ssl_rsa.c

/* ssl/ssl_rsa.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "ssl_locl.h"
#include <openssl/bio.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <openssl/pem.h>

static int ssl_set_cert(CERT *c, X509 *x509);
static int ssl_set_pkey(CERT *c, EVP_PKEY *pkey);
int SSL_use_certificate(SSL *ssl, X509 *x)
{
    if (x == NULL) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ssl->cert)) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    return (ssl_set_cert(ssl->cert, x));
}

#ifndef OPENSSL_NO_STDIO
int SSL_use_certificate_file(SSL *ssl, const char *file, int type)
{
    int j;
    BIO *in;
    int ret = 0;
    X509 *x = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        x = d2i_X509_bio(in, NULL);
    } else if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        x = PEM_read_bio_X509(in, NULL, ssl->ctx->default_passwd_callback,
                              ssl->ctx->default_passwd_callback_userdata);
    } else {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }

    if (x == NULL) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE_FILE, j);
        goto end;
    }

    ret = SSL_use_certificate(ssl, x);
 end:
    if (x != NULL)
        X509_free(x);
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
#endif

int SSL_use_certificate_ASN1(SSL *ssl, const unsigned char *d, int len)
{
    X509 *x;
    int ret;

    x = d2i_X509(NULL, &d, (long)len);
    if (x == NULL) {
        SSLerr(SSL_F_SSL_USE_CERTIFICATE_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_use_certificate(ssl, x);
    X509_free(x);
    return (ret);
}

#ifndef OPENSSL_NO_RSA
int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa)
{
    EVP_PKEY *pkey;
    int ret;

    if (rsa == NULL) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ssl->cert)) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    if ((pkey = EVP_PKEY_new()) == NULL) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY, ERR_R_EVP_LIB);
        return (0);
    }

    RSA_up_ref(rsa);
    EVP_PKEY_assign_RSA(pkey, rsa);

    ret = ssl_set_pkey(ssl->cert, pkey);
    EVP_PKEY_free(pkey);
    return (ret);
}
#endif

static int ssl_set_pkey(CERT *c, EVP_PKEY *pkey)
{
    int i;

    i = ssl_cert_type(NULL, pkey);
    if (i < 0) {
        SSLerr(SSL_F_SSL_SET_PKEY, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
        return (0);
    }

    if (c->pkeys[i].x509 != NULL) {
        EVP_PKEY *pktmp;
        pktmp = X509_get_pubkey(c->pkeys[i].x509);
        EVP_PKEY_copy_parameters(pktmp, pkey);
        EVP_PKEY_free(pktmp);
        ERR_clear_error();

#ifndef OPENSSL_NO_RSA
        /*
         * Don't check the public/private key, this is mostly for smart
         * cards.
         */
        if ((pkey->type == EVP_PKEY_RSA) &&
            (RSA_flags(pkey->pkey.rsa) & RSA_METHOD_FLAG_NO_CHECK)) ;
        else
#endif
        if (!X509_check_private_key(c->pkeys[i].x509, pkey)) {
            X509_free(c->pkeys[i].x509);
            c->pkeys[i].x509 = NULL;
            return 0;
        }
    }

    if (c->pkeys[i].privatekey != NULL)
        EVP_PKEY_free(c->pkeys[i].privatekey);
    CRYPTO_add(&pkey->references, 1, CRYPTO_LOCK_EVP_PKEY);
    c->pkeys[i].privatekey = pkey;
    c->key = &(c->pkeys[i]);

    c->valid = 0;
    return (1);
}

#ifndef OPENSSL_NO_RSA
# ifndef OPENSSL_NO_STDIO
int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file, int type)
{
    int j, ret = 0;
    BIO *in;
    RSA *rsa = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        rsa = d2i_RSAPrivateKey_bio(in, NULL);
    } else if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        rsa = PEM_read_bio_RSAPrivateKey(in, NULL,
                                         ssl->ctx->default_passwd_callback,
                                         ssl->
                                         ctx->default_passwd_callback_userdata);
    } else {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }
    if (rsa == NULL) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY_FILE, j);
        goto end;
    }
    ret = SSL_use_RSAPrivateKey(ssl, rsa);
    RSA_free(rsa);
 end:
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
# endif

int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, unsigned char *d, long len)
{
    int ret;
    const unsigned char *p;
    RSA *rsa;

    p = d;
    if ((rsa = d2i_RSAPrivateKey(NULL, &p, (long)len)) == NULL) {
        SSLerr(SSL_F_SSL_USE_RSAPRIVATEKEY_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_use_RSAPrivateKey(ssl, rsa);
    RSA_free(rsa);
    return (ret);
}
#endif                          /* !OPENSSL_NO_RSA */

int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey)
{
    int ret;

    if (pkey == NULL) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ssl->cert)) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    ret = ssl_set_pkey(ssl->cert, pkey);
    return (ret);
}

#ifndef OPENSSL_NO_STDIO
int SSL_use_PrivateKey_file(SSL *ssl, const char *file, int type)
{
    int j, ret = 0;
    BIO *in;
    EVP_PKEY *pkey = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        pkey = PEM_read_bio_PrivateKey(in, NULL,
                                       ssl->ctx->default_passwd_callback,
                                       ssl->
                                       ctx->default_passwd_callback_userdata);
    } else if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        pkey = d2i_PrivateKey_bio(in, NULL);
    } else {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }
    if (pkey == NULL) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY_FILE, j);
        goto end;
    }
    ret = SSL_use_PrivateKey(ssl, pkey);
    EVP_PKEY_free(pkey);
 end:
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
#endif

int SSL_use_PrivateKey_ASN1(int type, SSL *ssl, const unsigned char *d,
                            long len)
{
    int ret;
    const unsigned char *p;
    EVP_PKEY *pkey;

    p = d;
    if ((pkey = d2i_PrivateKey(type, NULL, &p, (long)len)) == NULL) {
        SSLerr(SSL_F_SSL_USE_PRIVATEKEY_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_use_PrivateKey(ssl, pkey);
    EVP_PKEY_free(pkey);
    return (ret);
}

int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x)
{
    if (x == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ctx->cert)) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    return (ssl_set_cert(ctx->cert, x));
}

static int ssl_set_cert(CERT *c, X509 *x)
{
    EVP_PKEY *pkey;
    int i;

    pkey = X509_get_pubkey(x);
    if (pkey == NULL) {
        SSLerr(SSL_F_SSL_SET_CERT, SSL_R_X509_LIB);
        return (0);
    }

    i = ssl_cert_type(x, pkey);
    if (i < 0) {
        SSLerr(SSL_F_SSL_SET_CERT, SSL_R_UNKNOWN_CERTIFICATE_TYPE);
        EVP_PKEY_free(pkey);
        return (0);
    }

    if (c->pkeys[i].privatekey != NULL) {
        EVP_PKEY_copy_parameters(pkey, c->pkeys[i].privatekey);
        ERR_clear_error();

#ifndef OPENSSL_NO_RSA
        /*
         * Don't check the public/private key, this is mostly for smart
         * cards.
         */
        if ((c->pkeys[i].privatekey->type == EVP_PKEY_RSA) &&
            (RSA_flags(c->pkeys[i].privatekey->pkey.rsa) &
             RSA_METHOD_FLAG_NO_CHECK)) ;
        else
#endif                          /* OPENSSL_NO_RSA */
        if (!X509_check_private_key(x, c->pkeys[i].privatekey)) {
            /*
             * don't fail for a cert/key mismatch, just free current private
             * key (when switching to a different cert & key, first this
             * function should be used, then ssl_set_pkey
             */
            EVP_PKEY_free(c->pkeys[i].privatekey);
            c->pkeys[i].privatekey = NULL;
            /* clear error queue */
            ERR_clear_error();
        }
    }

    EVP_PKEY_free(pkey);

    if (c->pkeys[i].x509 != NULL)
        X509_free(c->pkeys[i].x509);
    CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
    c->pkeys[i].x509 = x;
    c->key = &(c->pkeys[i]);

    c->valid = 0;
    return (1);
}

#ifndef OPENSSL_NO_STDIO
int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file, int type)
{
    int j;
    BIO *in;
    int ret = 0;
    X509 *x = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        x = d2i_X509_bio(in, NULL);
    } else if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        x = PEM_read_bio_X509(in, NULL, ctx->default_passwd_callback,
                              ctx->default_passwd_callback_userdata);
    } else {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }

    if (x == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_FILE, j);
        goto end;
    }

    ret = SSL_CTX_use_certificate(ctx, x);
 end:
    if (x != NULL)
        X509_free(x);
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
#endif

int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, int len,
                                 const unsigned char *d)
{
    X509 *x;
    int ret;

    x = d2i_X509(NULL, &d, (long)len);
    if (x == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_CTX_use_certificate(ctx, x);
    X509_free(x);
    return (ret);
}

#ifndef OPENSSL_NO_RSA
int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa)
{
    int ret;
    EVP_PKEY *pkey;

    if (rsa == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ctx->cert)) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    if ((pkey = EVP_PKEY_new()) == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY, ERR_R_EVP_LIB);
        return (0);
    }

    RSA_up_ref(rsa);
    EVP_PKEY_assign_RSA(pkey, rsa);

    ret = ssl_set_pkey(ctx->cert, pkey);
    EVP_PKEY_free(pkey);
    return (ret);
}

# ifndef OPENSSL_NO_STDIO
int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx, const char *file, int type)
{
    int j, ret = 0;
    BIO *in;
    RSA *rsa = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        rsa = d2i_RSAPrivateKey_bio(in, NULL);
    } else if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        rsa = PEM_read_bio_RSAPrivateKey(in, NULL,
                                         ctx->default_passwd_callback,
                                         ctx->default_passwd_callback_userdata);
    } else {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }
    if (rsa == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY_FILE, j);
        goto end;
    }
    ret = SSL_CTX_use_RSAPrivateKey(ctx, rsa);
    RSA_free(rsa);
 end:
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
# endif

int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx, const unsigned char *d,
                                   long len)
{
    int ret;
    const unsigned char *p;
    RSA *rsa;

    p = d;
    if ((rsa = d2i_RSAPrivateKey(NULL, &p, (long)len)) == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_RSAPRIVATEKEY_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_CTX_use_RSAPrivateKey(ctx, rsa);
    RSA_free(rsa);
    return (ret);
}
#endif                          /* !OPENSSL_NO_RSA */

int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey)
{
    if (pkey == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY, ERR_R_PASSED_NULL_PARAMETER);
        return (0);
    }
    if (!ssl_cert_inst(&ctx->cert)) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY, ERR_R_MALLOC_FAILURE);
        return (0);
    }
    return (ssl_set_pkey(ctx->cert, pkey));
}

#ifndef OPENSSL_NO_STDIO
int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file, int type)
{
    int j, ret = 0;
    BIO *in;
    EVP_PKEY *pkey = NULL;

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY_FILE, ERR_R_SYS_LIB);
        goto end;
    }
    if (type == SSL_FILETYPE_PEM) {
        j = ERR_R_PEM_LIB;
        pkey = PEM_read_bio_PrivateKey(in, NULL,
                                       ctx->default_passwd_callback,
                                       ctx->default_passwd_callback_userdata);
    } else if (type == SSL_FILETYPE_ASN1) {
        j = ERR_R_ASN1_LIB;
        pkey = d2i_PrivateKey_bio(in, NULL);
    } else {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY_FILE, SSL_R_BAD_SSL_FILETYPE);
        goto end;
    }
    if (pkey == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY_FILE, j);
        goto end;
    }
    ret = SSL_CTX_use_PrivateKey(ctx, pkey);
    EVP_PKEY_free(pkey);
 end:
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
#endif

int SSL_CTX_use_PrivateKey_ASN1(int type, SSL_CTX *ctx,
                                const unsigned char *d, long len)
{
    int ret;
    const unsigned char *p;
    EVP_PKEY *pkey;

    p = d;
    if ((pkey = d2i_PrivateKey(type, NULL, &p, (long)len)) == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_PRIVATEKEY_ASN1, ERR_R_ASN1_LIB);
        return (0);
    }

    ret = SSL_CTX_use_PrivateKey(ctx, pkey);
    EVP_PKEY_free(pkey);
    return (ret);
}

#ifndef OPENSSL_NO_STDIO
/*
 * Read a file that contains our certificate in "PEM" format, possibly
 * followed by a sequence of CA certificates that should be sent to the peer
 * in the Certificate message.
 */
int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx, const char *file)
{
    BIO *in;
    int ret = 0;
    X509 *x = NULL;

    ERR_clear_error();          /* clear error stack for
                                 * SSL_CTX_use_certificate() */

    in = BIO_new(BIO_s_file_internal());
    if (in == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_CHAIN_FILE, ERR_R_BUF_LIB);
        goto end;
    }

    if (BIO_read_filename(in, file) <= 0) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_CHAIN_FILE, ERR_R_SYS_LIB);
        goto end;
    }

    x = PEM_read_bio_X509_AUX(in, NULL, ctx->default_passwd_callback,
                              ctx->default_passwd_callback_userdata);
    if (x == NULL) {
        SSLerr(SSL_F_SSL_CTX_USE_CERTIFICATE_CHAIN_FILE, ERR_R_PEM_LIB);
        goto end;
    }

    ret = SSL_CTX_use_certificate(ctx, x);
    if (ERR_peek_error() != 0)
        ret = 0;                /* Key/certificate mismatch doesn't imply
                                 * ret==0 ... */
    if (ret) {
        /*
         * If we could set up our certificate, now proceed to the CA
         * certificates.
         */
        X509 *ca;
        int r;
        unsigned long err;

        if (ctx->extra_certs != NULL) {
            sk_X509_pop_free(ctx->extra_certs, X509_free);
            ctx->extra_certs = NULL;
        }

        while ((ca =
                PEM_read_bio_X509(in, NULL, ctx->default_passwd_callback,
                                  ctx->default_passwd_callback_userdata))
               != NULL) {
            r = SSL_CTX_add_extra_chain_cert(ctx, ca);
            if (!r) {
                X509_free(ca);
                ret = 0;
                goto end;
            }
            /*
             * Note that we must not free r if it was successfully added to
             * the chain (while we must free the main certificate, since its
             * reference count is increased by SSL_CTX_use_certificate).
             */
        }
        /* When the while loop ends, it's usually just EOF. */
        err = ERR_peek_last_error();
        if (ERR_GET_LIB(err) == ERR_LIB_PEM
            && ERR_GET_REASON(err) == PEM_R_NO_START_LINE)
            ERR_clear_error();
        else
            ret = 0;            /* some real error */
    }

 end:
    if (x != NULL)
        X509_free(x);
    if (in != NULL)
        BIO_free(in);
    return (ret);
}
#endif