/* $OpenBSD: x509_pci.c,v 1.2 2021/08/24 15:23:03 tb Exp $ */
/* Contributed to the OpenSSL Project 2004
 * by Richard Levitte (richard@levitte.org)
 */
/* Copyright (c) 2004 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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.
 */

#include <stdio.h>
#include <string.h>

#include <openssl/conf.h>
#include <openssl/err.h>
#include <openssl/x509v3.h>

static int i2r_pci(X509V3_EXT_METHOD *method, PROXY_CERT_INFO_EXTENSION *ext,
    BIO *out, int indent);
static PROXY_CERT_INFO_EXTENSION *r2i_pci(X509V3_EXT_METHOD *method,
    X509V3_CTX *ctx, char *str);

const X509V3_EXT_METHOD v3_pci = {
        .ext_nid = NID_proxyCertInfo,
        .ext_flags = 0,
        .it = &PROXY_CERT_INFO_EXTENSION_it,
        .ext_new = NULL,
        .ext_free = NULL,
        .d2i = NULL,
        .i2d = NULL,
        .i2s = NULL,
        .s2i = NULL,
        .i2v = NULL,
        .v2i = NULL,
        .i2r = (X509V3_EXT_I2R)i2r_pci,
        .r2i = (X509V3_EXT_R2I)r2i_pci,
        .usr_data = NULL,
};

static int
i2r_pci(X509V3_EXT_METHOD *method, PROXY_CERT_INFO_EXTENSION *pci, BIO *out,
    int indent)
{
        BIO_printf(out, "%*sPath Length Constraint: ", indent, "");
        if (pci->pcPathLengthConstraint)
                i2a_ASN1_INTEGER(out, pci->pcPathLengthConstraint);
        else
                BIO_printf(out, "infinite");
        BIO_puts(out, "\n");
        BIO_printf(out, "%*sPolicy Language: ", indent, "");
        i2a_ASN1_OBJECT(out, pci->proxyPolicy->policyLanguage);
        BIO_puts(out, "\n");
        if (pci->proxyPolicy->policy && pci->proxyPolicy->policy->data)
                BIO_printf(out, "%*sPolicy Text: %.*s\n", indent, "",
                    pci->proxyPolicy->policy->length,
                    pci->proxyPolicy->policy->data);
        return 1;
}

static int
process_pci_value(CONF_VALUE *val, ASN1_OBJECT **language,
    ASN1_INTEGER **pathlen, ASN1_OCTET_STRING **policy)
{
        int free_policy = 0;

        if (strcmp(val->name, "language") == 0) {
                if (*language) {
                        X509V3error(X509V3_R_POLICY_LANGUAGE_ALREADY_DEFINED);
                        X509V3_conf_err(val);
                        return 0;
                }
                if (!(*language = OBJ_txt2obj(val->value, 0))) {
                        X509V3error(X509V3_R_INVALID_OBJECT_IDENTIFIER);
                        X509V3_conf_err(val);
                        return 0;
                }
        }
        else if (strcmp(val->name, "pathlen") == 0) {
                if (*pathlen) {
                        X509V3error(X509V3_R_POLICY_PATH_LENGTH_ALREADY_DEFINED);
                        X509V3_conf_err(val);
                        return 0;
                }
                if (!X509V3_get_value_int(val, pathlen)) {
                        X509V3error(X509V3_R_POLICY_PATH_LENGTH);
                        X509V3_conf_err(val);
                        return 0;
                }
        }
        else if (strcmp(val->name, "policy") == 0) {
                unsigned char *tmp_data = NULL;
                long val_len;
                if (!*policy) {
                        *policy = ASN1_OCTET_STRING_new();
                        if (!*policy) {
                                X509V3error(ERR_R_MALLOC_FAILURE);
                                X509V3_conf_err(val);
                                return 0;
                        }
                        free_policy = 1;
                }
                if (strncmp(val->value, "hex:", 4) == 0) {
                        unsigned char *tmp_data2 =
                            string_to_hex(val->value + 4, &val_len);

                        if (!tmp_data2) {
                                X509V3error(X509V3_R_ILLEGAL_HEX_DIGIT);
                                X509V3_conf_err(val);
                                goto err;
                        }

                        tmp_data = realloc((*policy)->data,
                            (*policy)->length + val_len + 1);
                        if (tmp_data) {
                                (*policy)->data = tmp_data;
                                memcpy(&(*policy)->data[(*policy)->length],
                                    tmp_data2, val_len);
                                (*policy)->length += val_len;
                                (*policy)->data[(*policy)->length] = '\0';
                        } else {
                                free(tmp_data2);
                                free((*policy)->data);
                                (*policy)->data = NULL;
                                (*policy)->length = 0;
                                X509V3error(ERR_R_MALLOC_FAILURE);
                                X509V3_conf_err(val);
                                goto err;
                        }
                        free(tmp_data2);
                }
                else if (strncmp(val->value, "file:", 5) == 0) {
                        unsigned char buf[2048];
                        int n;
                        BIO *b = BIO_new_file(val->value + 5, "r");
                        if (!b) {
                                X509V3error(ERR_R_BIO_LIB);
                                X509V3_conf_err(val);
                                goto err;
                        }
                        while ((n = BIO_read(b, buf, sizeof(buf))) > 0 ||
                            (n == 0 && BIO_should_retry(b))) {
                                if (!n)
                                        continue;

                                tmp_data = realloc((*policy)->data,
                                    (*policy)->length + n + 1);

                                if (!tmp_data)
                                        break;

                                (*policy)->data = tmp_data;
                                memcpy(&(*policy)->data[(*policy)->length],
                                    buf, n);
                                (*policy)->length += n;
                                (*policy)->data[(*policy)->length] = '\0';
                        }
                        BIO_free_all(b);

                        if (n < 0) {
                                X509V3error(ERR_R_BIO_LIB);
                                X509V3_conf_err(val);
                                goto err;
                        }
                }
                else if (strncmp(val->value, "text:", 5) == 0) {
                        val_len = strlen(val->value + 5);
                        tmp_data = realloc((*policy)->data,
                            (*policy)->length + val_len + 1);
                        if (tmp_data) {
                                (*policy)->data = tmp_data;
                                memcpy(&(*policy)->data[(*policy)->length],
                                    val->value + 5, val_len);
                                (*policy)->length += val_len;
                                (*policy)->data[(*policy)->length] = '\0';
                        } else {
                                free((*policy)->data);
                                (*policy)->data = NULL;
                                (*policy)->length = 0;
                                X509V3error(ERR_R_MALLOC_FAILURE);
                                X509V3_conf_err(val);
                                goto err;
                        }
                } else {
                        X509V3error(X509V3_R_INCORRECT_POLICY_SYNTAX_TAG);
                        X509V3_conf_err(val);
                        goto err;
                }
                if (!tmp_data) {
                        X509V3error(ERR_R_MALLOC_FAILURE);
                        X509V3_conf_err(val);
                        goto err;
                }
        }
        return 1;

err:
        if (free_policy) {
                ASN1_OCTET_STRING_free(*policy);
                *policy = NULL;
        }
        return 0;
}

static PROXY_CERT_INFO_EXTENSION *
r2i_pci(X509V3_EXT_METHOD *method, X509V3_CTX *ctx, char *value)
{
        PROXY_CERT_INFO_EXTENSION *pci = NULL;
        STACK_OF(CONF_VALUE) *vals;
        ASN1_OBJECT *language = NULL;
        ASN1_INTEGER *pathlen = NULL;
        ASN1_OCTET_STRING *policy = NULL;
        int i, j;

        vals = X509V3_parse_list(value);
        for (i = 0; i < sk_CONF_VALUE_num(vals); i++) {
                CONF_VALUE *cnf = sk_CONF_VALUE_value(vals, i);
                if (!cnf->name || (*cnf->name != '@' && !cnf->value)) {
                        X509V3error(X509V3_R_INVALID_PROXY_POLICY_SETTING);
                        X509V3_conf_err(cnf);
                        goto err;
                }
                if (*cnf->name == '@') {
                        STACK_OF(CONF_VALUE) *sect;
                        int success_p = 1;

                        sect = X509V3_get_section(ctx, cnf->name + 1);
                        if (!sect) {
                                X509V3error(X509V3_R_INVALID_SECTION);
                                X509V3_conf_err(cnf);
                                goto err;
                        }
                        for (j = 0; success_p &&
                            j < sk_CONF_VALUE_num(sect); j++) {
                                success_p = process_pci_value(
                                    sk_CONF_VALUE_value(sect, j),
                                    &language, &pathlen, &policy);
                        }
                        X509V3_section_free(ctx, sect);
                        if (!success_p)
                                goto err;
                } else {
                        if (!process_pci_value(cnf,
                            &language, &pathlen, &policy)) {
                                X509V3_conf_err(cnf);
                                goto err;
                        }
                }
        }

        /* Language is mandatory */
        if (!language) {
                X509V3error(X509V3_R_NO_PROXY_CERT_POLICY_LANGUAGE_DEFINED);
                goto err;
        }
        i = OBJ_obj2nid(language);
        if ((i == NID_Independent || i == NID_id_ppl_inheritAll) && policy) {
                X509V3error(X509V3_R_POLICY_WHEN_PROXY_LANGUAGE_REQUIRES_NO_POLICY);
                goto err;
        }

        pci = PROXY_CERT_INFO_EXTENSION_new();
        if (!pci) {
                X509V3error(ERR_R_MALLOC_FAILURE);
                goto err;
        }

        pci->proxyPolicy->policyLanguage = language;
        language = NULL;
        pci->proxyPolicy->policy = policy;
        policy = NULL;
        pci->pcPathLengthConstraint = pathlen;
        pathlen = NULL;
        goto end;

err:
        ASN1_OBJECT_free(language);
        language = NULL;
        ASN1_INTEGER_free(pathlen);
        pathlen = NULL;
        ASN1_OCTET_STRING_free(policy);
        policy = NULL;
end:
        sk_CONF_VALUE_pop_free(vals, X509V3_conf_free);
        return pci;
}