root/trunk/src/libopensc/pkcs15-cert.c

/*
 * pkcs15-cert.c: PKCS #15 certificate functions
 *
 * Copyright (C) 2001, 2002  Juha YrjölÀ <juha.yrjola@iki.fi>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "internal.h"
#include "pkcs15.h"
#include "asn1.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <assert.h>

static int parse_x509_cert(sc_context_t *ctx, const u8 *buf, size_t buflen, struct sc_pkcs15_cert *cert)
{
        int r;
        struct sc_algorithm_id pk_alg, sig_alg;
        sc_pkcs15_der_t pk = { NULL, 0 };
        struct sc_asn1_entry asn1_version[] = {
                { "version", SC_ASN1_INTEGER, SC_ASN1_TAG_INTEGER, 0, &cert->version, NULL },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        struct sc_asn1_entry asn1_pkinfo[] = {
                { "algorithm",          SC_ASN1_ALGORITHM_ID,  SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, &pk_alg, NULL },
                { "subjectPublicKey",   SC_ASN1_BIT_STRING_NI, SC_ASN1_TAG_BIT_STRING, SC_ASN1_ALLOC, &pk.value, &pk.len },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        struct sc_asn1_entry asn1_x509v3[] = {
                { "certificatePolicies",        SC_ASN1_OCTET_STRING, SC_ASN1_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
                { "subjectKeyIdentifier",       SC_ASN1_OCTET_STRING, SC_ASN1_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
                { "crlDistributionPoints",      SC_ASN1_OCTET_STRING, SC_ASN1_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, &cert->crl, &cert->crl_len },
                { "authorityKeyIdentifier",     SC_ASN1_OCTET_STRING, SC_ASN1_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
                { "keyUsage",                   SC_ASN1_BOOLEAN, SC_ASN1_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        struct sc_asn1_entry asn1_extensions[] = {
                { "x509v3",             SC_ASN1_STRUCT,    SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, asn1_x509v3, NULL },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        struct sc_asn1_entry asn1_tbscert[] = {
                { "version",            SC_ASN1_STRUCT,    SC_ASN1_CTX | 0 | SC_ASN1_CONS, SC_ASN1_OPTIONAL, asn1_version, NULL },
                { "serialNumber",       SC_ASN1_OCTET_STRING, SC_ASN1_TAG_INTEGER, SC_ASN1_ALLOC, &cert->serial, &cert->serial_len },
                { "signature",          SC_ASN1_STRUCT,    SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, NULL, NULL },
                { "issuer",             SC_ASN1_OCTET_STRING, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, SC_ASN1_ALLOC, &cert->issuer, &cert->issuer_len },
                { "validity",           SC_ASN1_STRUCT,    SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, NULL, NULL },
                { "subject",            SC_ASN1_OCTET_STRING, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, SC_ASN1_ALLOC, &cert->subject, &cert->subject_len },
                { "subjectPublicKeyInfo",SC_ASN1_STRUCT,   SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, asn1_pkinfo, NULL },
                { "extensions",         SC_ASN1_STRUCT,    SC_ASN1_CTX | 3 | SC_ASN1_CONS, SC_ASN1_OPTIONAL, asn1_extensions, NULL },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        struct sc_asn1_entry asn1_cert[] = {
                { "tbsCertificate",     SC_ASN1_STRUCT,    SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, asn1_tbscert, NULL },
                { "signatureAlgorithm", SC_ASN1_ALGORITHM_ID, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, &sig_alg, NULL },
                { "signatureValue",     SC_ASN1_BIT_STRING, SC_ASN1_TAG_BIT_STRING, 0, NULL, NULL },
                { NULL, 0, 0, 0, NULL, NULL }
        };
        const u8 *obj;
        size_t objlen;
        
        memset(cert, 0, sizeof(*cert));
        obj = sc_asn1_verify_tag(ctx, buf, buflen, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS,
                                 &objlen);
        if (obj == NULL) {
                sc_error(ctx, "X.509 certificate not found\n");
                return SC_ERROR_INVALID_ASN1_OBJECT;
        }
        cert->data_len = objlen + (obj - buf);
        r = sc_asn1_decode(ctx, asn1_cert, obj, objlen, NULL, NULL);
        SC_TEST_RET(ctx, r, "ASN.1 parsing of certificate failed");

        cert->version++;

        cert->key.algorithm = pk_alg.algorithm;
        pk.len >>= 3;   /* convert number of bits to bytes */
        cert->key.data = pk;

        r = sc_pkcs15_decode_pubkey(ctx, &cert->key, pk.value, pk.len);
        if (r < 0)
                free(pk.value);
        sc_asn1_clear_algorithm_id(&pk_alg);
        sc_asn1_clear_algorithm_id(&sig_alg);

        return r;
}

int sc_pkcs15_read_certificate(struct sc_pkcs15_card *p15card,
                               const struct sc_pkcs15_cert_info *info,
                               struct sc_pkcs15_cert **cert_out)
{
        int r;
        struct sc_pkcs15_cert *cert;
        u8 *data = NULL;
        size_t len;
        
        assert(p15card != NULL && info != NULL && cert_out != NULL);
        SC_FUNC_CALLED(p15card->card->ctx, 1);

        if (info->path.len) {
                r = sc_pkcs15_read_file(p15card, &info->path, &data, &len, NULL);
                if (r)
                        return r;
        } else {
                sc_pkcs15_der_t copy;

                sc_der_copy(&copy, &info->value);
                data = copy.value;
                len = copy.len;
        }

        cert = (struct sc_pkcs15_cert *) malloc(sizeof(struct sc_pkcs15_cert));
        if (cert == NULL) {
                free(data);
                return SC_ERROR_OUT_OF_MEMORY;
        }
        memset(cert, 0, sizeof(struct sc_pkcs15_cert));
        if (parse_x509_cert(p15card->card->ctx, data, len, cert)) {
                free(data);
                free(cert);
                return SC_ERROR_INVALID_ASN1_OBJECT;
        }
        cert->data = data;
        *cert_out = cert;
        return 0;
}

static const struct sc_asn1_entry c_asn1_cred_ident[] = {
        { "idType",     SC_ASN1_INTEGER,      SC_ASN1_TAG_INTEGER, 0, NULL, NULL },
        { "idValue",    SC_ASN1_OCTET_STRING, SC_ASN1_TAG_OCTET_STRING, 0, NULL, NULL },
        { NULL, 0, 0, 0, NULL, NULL }
};
static const struct sc_asn1_entry c_asn1_com_cert_attr[] = {
        { "iD",         SC_ASN1_PKCS15_ID, SC_ASN1_TAG_OCTET_STRING, 0, NULL, NULL },
        { "authority",  SC_ASN1_BOOLEAN,   SC_ASN1_TAG_BOOLEAN, SC_ASN1_OPTIONAL, NULL, NULL },
        { "identifier", SC_ASN1_STRUCT,    SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
        /* FIXME: Add rest of the optional fields */
        { NULL, 0, 0, 0, NULL, NULL }
};
static const struct sc_asn1_entry c_asn1_x509_cert_value_choice[] = {
        { "path",       SC_ASN1_PATH,      SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, SC_ASN1_OPTIONAL, NULL, NULL },
        { "direct",     SC_ASN1_OCTET_STRING, SC_ASN1_CTX | 0 | SC_ASN1_CONS, SC_ASN1_OPTIONAL | SC_ASN1_ALLOC, NULL, NULL },
        { NULL, 0, 0, 0, NULL, NULL }
};
static const struct sc_asn1_entry c_asn1_x509_cert_attr[] = {
        { "value",      SC_ASN1_CHOICE, 0, 0, NULL, NULL },
        { NULL, 0, 0, 0, NULL, NULL }
};
static const struct sc_asn1_entry c_asn1_type_cert_attr[] = {
        { "x509CertificateAttributes", SC_ASN1_STRUCT, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, NULL, NULL },
        { NULL, 0, 0, 0, NULL, NULL }
};
static const struct sc_asn1_entry c_asn1_cert[] = {
        { "x509Certificate", SC_ASN1_PKCS15_OBJECT, SC_ASN1_TAG_SEQUENCE | SC_ASN1_CONS, 0, NULL, NULL },
        { NULL, 0, 0, 0, NULL, NULL }
};

int sc_pkcs15_decode_cdf_entry(struct sc_pkcs15_card *p15card,
                               struct sc_pkcs15_object *obj,
                               const u8 ** buf, size_t *buflen)
{
        sc_context_t *ctx = p15card->card->ctx;
        struct sc_pkcs15_cert_info info;
        struct sc_asn1_entry    asn1_cred_ident[3], asn1_com_cert_attr[4],
                                asn1_x509_cert_attr[2], asn1_type_cert_attr[2],
                                asn1_cert[2], asn1_x509_cert_value_choice[3];
        struct sc_asn1_pkcs15_object cert_obj = { obj, asn1_com_cert_attr, NULL,
                                             asn1_type_cert_attr };
        sc_pkcs15_der_t *der = &info.value;
        u8 id_value[128];
        int id_type;
        size_t id_value_len = sizeof(id_value);
        int r;

        sc_copy_asn1_entry(c_asn1_cred_ident, asn1_cred_ident);
        sc_copy_asn1_entry(c_asn1_com_cert_attr, asn1_com_cert_attr);
        sc_copy_asn1_entry(c_asn1_x509_cert_attr, asn1_x509_cert_attr);
        sc_copy_asn1_entry(c_asn1_x509_cert_value_choice, asn1_x509_cert_value_choice);
        sc_copy_asn1_entry(c_asn1_type_cert_attr, asn1_type_cert_attr);
        sc_copy_asn1_entry(c_asn1_cert, asn1_cert);
        
        sc_format_asn1_entry(asn1_cred_ident + 0, &id_type, NULL, 0);
        sc_format_asn1_entry(asn1_cred_ident + 1, &id_value, &id_value_len, 0);
        sc_format_asn1_entry(asn1_com_cert_attr + 0, &info.id, NULL, 0);
        sc_format_asn1_entry(asn1_com_cert_attr + 1, &info.authority, NULL, 0);
        sc_format_asn1_entry(asn1_com_cert_attr + 2, asn1_cred_ident, NULL, 0);
        sc_format_asn1_entry(asn1_x509_cert_attr + 0, asn1_x509_cert_value_choice, NULL, 0);
        sc_format_asn1_entry(asn1_x509_cert_value_choice + 0, &info.path, NULL, 0);
        sc_format_asn1_entry(asn1_x509_cert_value_choice + 1, &der->value, &der->len, 0);
        sc_format_asn1_entry(asn1_type_cert_attr + 0, asn1_x509_cert_attr, NULL, 0);
        sc_format_asn1_entry(asn1_cert + 0, &cert_obj, NULL, 0);

        /* Fill in defaults */
        memset(&info, 0, sizeof(info));
        info.authority = 0;
        
        r = sc_asn1_decode(ctx, asn1_cert, *buf, *buflen, buf, buflen);
        /* In case of error, trash the cert value (direct coding) */
        if (r < 0 && der->value)
                free(der->value);
        if (r == SC_ERROR_ASN1_END_OF_CONTENTS)
                return r;
        SC_TEST_RET(ctx, r, "ASN.1 decoding failed");
        r = sc_pkcs15_make_absolute_path(&p15card->file_app->path, &info.path);
        if (r < 0)
                return r;
        obj->type = SC_PKCS15_TYPE_CERT_X509;
        obj->data = malloc(sizeof(info));
        if (obj->data == NULL)
                SC_FUNC_RETURN(ctx, 0, SC_ERROR_OUT_OF_MEMORY);
        memcpy(obj->data, &info, sizeof(info));

        return 0;
}

int sc_pkcs15_encode_cdf_entry(sc_context_t *ctx,
                               const struct sc_pkcs15_object *obj,
                               u8 **buf, size_t *bufsize)
{
        struct sc_asn1_entry    asn1_cred_ident[3], asn1_com_cert_attr[4],
                                asn1_x509_cert_attr[2], asn1_type_cert_attr[2],
                                asn1_cert[2], asn1_x509_cert_value_choice[3];
        struct sc_pkcs15_cert_info *infop = (sc_pkcs15_cert_info_t *) obj->data;
        sc_pkcs15_der_t *der = &infop->value;
        struct sc_asn1_pkcs15_object cert_obj = { (struct sc_pkcs15_object *) obj,
                                                        asn1_com_cert_attr, NULL,
                                                        asn1_type_cert_attr };
        int r;

        sc_copy_asn1_entry(c_asn1_cred_ident, asn1_cred_ident);
        sc_copy_asn1_entry(c_asn1_com_cert_attr, asn1_com_cert_attr);
        sc_copy_asn1_entry(c_asn1_x509_cert_attr, asn1_x509_cert_attr);
        sc_copy_asn1_entry(c_asn1_x509_cert_value_choice, asn1_x509_cert_value_choice);
        sc_copy_asn1_entry(c_asn1_type_cert_attr, asn1_type_cert_attr);
        sc_copy_asn1_entry(c_asn1_cert, asn1_cert);
        
        sc_format_asn1_entry(asn1_com_cert_attr + 0, (void *) &infop->id, NULL, 1);
        if (infop->authority)
                sc_format_asn1_entry(asn1_com_cert_attr + 1, (void *) &infop->authority, NULL, 1);
        if (infop->path.len || !der->value) {
                sc_format_asn1_entry(asn1_x509_cert_value_choice + 0, &infop->path, NULL, 1);
        } else {
                sc_format_asn1_entry(asn1_x509_cert_value_choice + 1, der->value, &der->len, 1);
        }
        sc_format_asn1_entry(asn1_type_cert_attr + 0, &asn1_x509_cert_value_choice, NULL, 1);
        sc_format_asn1_entry(asn1_cert + 0, (void *) &cert_obj, NULL, 1);

        r = sc_asn1_encode(ctx, asn1_cert, buf, bufsize);

        return r;
}

void sc_pkcs15_free_certificate(struct sc_pkcs15_cert *cert)
{
        assert(cert != NULL);

        sc_pkcs15_erase_pubkey(&cert->key);
        free(cert->subject);
        free(cert->issuer);
        free(cert->serial);
        free(cert->data);
        free(cert->crl);
        free(cert);
}

void sc_pkcs15_free_cert_info(sc_pkcs15_cert_info_t *cert)
{
        if (!cert)
                return;
        if (cert->value.value)
                free(cert->value.value);
        free(cert);
}