/*

 * Copyright 1999-2016 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

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/pkcs12.h>

/* Simplified PKCS#12 routines */

static int parse_pk12(PKCS12 *p12, const char *pass, int passlen,

                      EVP_PKEY **pkey, STACK_OF(X509) *ocerts);

static int parse_bags(const STACK_OF(PKCS12_SAFEBAG) *bags, const char *pass,

                      int passlen, EVP_PKEY **pkey, STACK_OF(X509) *ocerts);

static int parse_bag(PKCS12_SAFEBAG *bag, const char *pass, int passlen,

                     EVP_PKEY **pkey, STACK_OF(X509) *ocerts);

/*

 * Parse and decrypt a PKCS#12 structure returning user key, user cert and

 * other (CA) certs. Note either ca should be NULL, *ca should be NULL, or it

 * should point to a valid STACK structure. pkey and cert can be passed

 * uninitialised.

 */

int PKCS12_parse(PKCS12 *p12, const char *pass, EVP_PKEY **pkey, X509 **cert,

                 STACK_OF(X509) **ca)

{

    STACK_OF(X509) *ocerts = NULL;

    X509 *x = NULL;

    if (pkey)

        *pkey = NULL;

    if (cert)

        *cert = NULL;

    /* Check for NULL PKCS12 structure */

    if (!p12) {

        PKCS12err(PKCS12_F_PKCS12_PARSE,

                  PKCS12_R_INVALID_NULL_PKCS12_POINTER);

        return 0;

    }

    /* Check the mac */

    /*

     * If password is zero length or NULL then try verifying both cases to

     * determine which password is correct. The reason for this is that under

     * PKCS#12 password based encryption no password and a zero length

     * password are two different things...

     */

    if (!pass || !*pass) {

        if (PKCS12_verify_mac(p12, NULL, 0))

            pass = NULL;

        else if (PKCS12_verify_mac(p12, "", 0))

            pass = "";

        else {

            PKCS12err(PKCS12_F_PKCS12_PARSE, PKCS12_R_MAC_VERIFY_FAILURE);

            goto err;

        }

    } else if (!PKCS12_verify_mac(p12, pass, -1)) {

        PKCS12err(PKCS12_F_PKCS12_PARSE, PKCS12_R_MAC_VERIFY_FAILURE);

        goto err;

    }

    /* Allocate stack for other certificates */

    ocerts = sk_X509_new_null();

    if (!ocerts) {

        PKCS12err(PKCS12_F_PKCS12_PARSE, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (!parse_pk12(p12, pass, -1, pkey, ocerts)) {

        PKCS12err(PKCS12_F_PKCS12_PARSE, PKCS12_R_PARSE_ERROR);

        goto err;

    }

    while ((x = sk_X509_pop(ocerts))) {

        if (pkey && *pkey && cert && !*cert) {

            ERR_set_mark();

            if (X509_check_private_key(x, *pkey)) {

                *cert = x;

                x = NULL;

            }

            ERR_pop_to_mark();

        }

        if (ca && x) {

            if (!*ca)

                *ca = sk_X509_new_null();

            if (!*ca)

                goto err;

            if (!sk_X509_push(*ca, x))

                goto err;

            x = NULL;

        }

        X509_free(x);

    }

    sk_X509_pop_free(ocerts, X509_free);

    return 1;

 err:

    if (pkey) {

        EVP_PKEY_free(*pkey);

        *pkey = NULL;

    }

    if (cert) {

        X509_free(*cert);

        *cert = NULL;

    }

    X509_free(x);

    sk_X509_pop_free(ocerts, X509_free);

    return 0;

}

/* Parse the outer PKCS#12 structure */

static int parse_pk12(PKCS12 *p12, const char *pass, int passlen,

                      EVP_PKEY **pkey, STACK_OF(X509) *ocerts)

{

    STACK_OF(PKCS7) *asafes;

    STACK_OF(PKCS12_SAFEBAG) *bags;

    int i, bagnid;

    PKCS7 *p7;

    if ((asafes = PKCS12_unpack_authsafes(p12)) == NULL)

        return 0;

    for (i = 0; i < sk_PKCS7_num(asafes); i++) {

        p7 = sk_PKCS7_value(asafes, i);

        bagnid = OBJ_obj2nid(p7->type);

        if (bagnid == NID_pkcs7_data) {

            bags = PKCS12_unpack_p7data(p7);

        } else if (bagnid == NID_pkcs7_encrypted) {

            bags = PKCS12_unpack_p7encdata(p7, pass, passlen);

        } else

            continue;

        if (!bags) {

            sk_PKCS7_pop_free(asafes, PKCS7_free);

            return 0;

        }

        if (!parse_bags(bags, pass, passlen, pkey, ocerts)) {

            sk_PKCS12_SAFEBAG_pop_free(bags, PKCS12_SAFEBAG_free);

            sk_PKCS7_pop_free(asafes, PKCS7_free);

            return 0;

        }

        sk_PKCS12_SAFEBAG_pop_free(bags, PKCS12_SAFEBAG_free);

    }

    sk_PKCS7_pop_free(asafes, PKCS7_free);

    return 1;

}

static int parse_bags(const STACK_OF(PKCS12_SAFEBAG) *bags, const char *pass,

                      int passlen, EVP_PKEY **pkey, STACK_OF(X509) *ocerts)

{

    int i;

    for (i = 0; i < sk_PKCS12_SAFEBAG_num(bags); i++) {

        if (!parse_bag(sk_PKCS12_SAFEBAG_value(bags, i),

                       pass, passlen, pkey, ocerts))

            return 0;

    }

    return 1;

}

static int parse_bag(PKCS12_SAFEBAG *bag, const char *pass, int passlen,

                     EVP_PKEY **pkey, STACK_OF(X509) *ocerts)

{

    PKCS8_PRIV_KEY_INFO *p8;

    X509 *x509;

    const ASN1_TYPE *attrib;

    ASN1_BMPSTRING *fname = NULL;

    ASN1_OCTET_STRING *lkid = NULL;

    if ((attrib = PKCS12_SAFEBAG_get0_attr(bag, NID_friendlyName)))

        fname = attrib->value.bmpstring;

    if ((attrib = PKCS12_SAFEBAG_get0_attr(bag, NID_localKeyID)))

        lkid = attrib->value.octet_string;

    switch (PKCS12_SAFEBAG_get_nid(bag)) {

    case NID_keyBag:

        if (!pkey || *pkey)

            return 1;

        *pkey = EVP_PKCS82PKEY(PKCS12_SAFEBAG_get0_p8inf(bag));

        if (*pkey == NULL)

            return 0;

        break;

    case NID_pkcs8ShroudedKeyBag:

        if (!pkey || *pkey)

            return 1;

        if ((p8 = PKCS12_decrypt_skey(bag, pass, passlen)) == NULL)

            return 0;

        *pkey = EVP_PKCS82PKEY(p8);

        PKCS8_PRIV_KEY_INFO_free(p8);

        if (!(*pkey))

            return 0;

        break;

    case NID_certBag:

        if (PKCS12_SAFEBAG_get_bag_nid(bag) != NID_x509Certificate)

            return 1;

        if ((x509 = PKCS12_SAFEBAG_get1_cert(bag)) == NULL)

            return 0;

        if (lkid && !X509_keyid_set1(x509, lkid->data, lkid->length)) {

            X509_free(x509);

            return 0;

        }

        if (fname) {

            int len, r;

            unsigned char *data;

            len = ASN1_STRING_to_UTF8(&data, fname);

            if (len >= 0) {

                r = X509_alias_set1(x509, data, len);

                OPENSSL_free(data);

                if (!r) {

                    X509_free(x509);

                    return 0;

                }

            }

        }

        if (!sk_X509_push(ocerts, x509)) {

            X509_free(x509);

            return 0;

        }

        break;

    case NID_safeContentsBag:

        return parse_bags(PKCS12_SAFEBAG_get0_safes(bag), pass, passlen, pkey,

                          ocerts);

    default:

        return 1;

    }

    return 1;

}