/*
 * Copyright (c) 2005 - 2006 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 "hx_locl.h"

int
_hx509_map_file_os(const char *fn, heim_octet_string *os)
{
    size_t length;
    void *data;
    int ret;

    ret = rk_undumpdata(fn, &data, &length);

    os->data = data;
    os->length = length;

    return ret;
}

void
_hx509_unmap_file_os(heim_octet_string *os)
{
    rk_xfree(os->data);
}

int
_hx509_write_file(const char *fn, const void *data, size_t length)
{
    rk_dumpdata(fn, data, length);
    return 0;
}

/*
 *
 */

static void
print_pem_stamp(FILE *f, const char *type, const char *str)
{
    fprintf(f, "-----%s %s-----\n", type, str);
}

int
hx509_pem_write(hx509_context context, const char *type,
                hx509_pem_header *headers, FILE *f,
                const void *data, size_t size)
{
    const char *p = data;
    size_t length;
    char *line;

#define ENCODE_LINE_LENGTH      54

    print_pem_stamp(f, "BEGIN", type);

    while (headers) {
        fprintf(f, "%s: %s\n%s",
                headers->header, headers->value,
                headers->next ? "" : "\n");
        headers = headers->next;
    }

    while (size > 0) {
        ssize_t l;

        length = size;
        if (length > ENCODE_LINE_LENGTH)
            length = ENCODE_LINE_LENGTH;

        l = base64_encode(p, length, &line);
        if (l < 0) {
            hx509_set_error_string(context, 0, ENOMEM,
                                   "malloc - out of memory");
            return ENOMEM;
        }
        size -= length;
        fprintf(f, "%s\n", line);
        p += length;
        free(line);
    }

    print_pem_stamp(f, "END", type);

    return 0;
}

/*
 *
 */

int
hx509_pem_add_header(hx509_pem_header **headers,
                     const char *header, const char *value)
{
    hx509_pem_header *h;

    h = calloc(1, sizeof(*h));
    if (h == NULL)
        return ENOMEM;
    h->header = strdup(header);
    if (h->header == NULL) {
        free(h);
        return ENOMEM;
    }
    h->value = strdup(value);
    if (h->value == NULL) {
        free(h->header);
        free(h);
        return ENOMEM;
    }

    h->next = *headers;
    *headers = h;

    return 0;
}

void
hx509_pem_free_header(hx509_pem_header *headers)
{
    hx509_pem_header *h;
    while (headers) {
        h = headers;
        headers = headers->next;
        free(h->header);
        free(h->value);
        free(h);
    }
}

/*
 *
 */

const char *
hx509_pem_find_header(const hx509_pem_header *h, const char *header)
{
    while(h) {
        if (strcmp(header, h->header) == 0)
            return h->value;
        h = h->next;
    }
    return NULL;
}


/*
 *
 */

int
hx509_pem_read(hx509_context context,
               FILE *f,
               hx509_pem_read_func func,
               void *ctx)
{
    hx509_pem_header *headers = NULL;
    char *type = NULL;
    void *data = NULL;
    size_t len = 0;
    char buf[1024];
    int ret = HX509_PARSING_KEY_FAILED;

    enum { BEFORE, SEARCHHEADER, INHEADER, INDATA, DONE } where;

    where = BEFORE;

    while (fgets(buf, sizeof(buf), f) != NULL) {
        char *p;
        int i;

        i = strcspn(buf, "\n");
        if (buf[i] == '\n') {
            buf[i] = '\0';
            if (i > 0)
                i--;
        }
        if (buf[i] == '\r') {
            buf[i] = '\0';
            if (i > 0)
                i--;
        }

        switch (where) {
        case BEFORE:
            if (strncmp("-----BEGIN ", buf, 11) == 0) {
                type = strdup(buf + 11);
                if (type == NULL)
                    break;
                p = strchr(type, '-');
                if (p)
                    *p = '\0';
                where = SEARCHHEADER;
            }
            break;
        case SEARCHHEADER:
            p = strchr(buf, ':');
            if (p == NULL) {
                where = INDATA;
                goto indata;
            }
            /* FALLTHOUGH */
        case INHEADER:
            if (buf[0] == '\0') {
                where = INDATA;
                break;
            }
            p = strchr(buf, ':');
            if (p) {
                *p++ = '\0';
                while (isspace((int)*p))
                    p++;
                ret = hx509_pem_add_header(&headers, buf, p);
                if (ret)
                    abort();
            }
            break;
        case INDATA:
        indata:

            if (strncmp("-----END ", buf, 9) == 0) {
                where = DONE;
                break;
            }

            p = emalloc(i);
            i = base64_decode(buf, p);
            if (i < 0) {
                free(p);
                goto out;
            }

            data = erealloc(data, len + i);
            memcpy(((char *)data) + len, p, i);
            free(p);
            len += i;
            break;
        case DONE:
            abort();
        }

        if (where == DONE) {
            ret = (*func)(context, type, headers, data, len, ctx);
        out:
            free(data);
            data = NULL;
            len = 0;
            free(type);
            type = NULL;
            where = BEFORE;
            hx509_pem_free_header(headers);
            headers = NULL;
            if (ret)
                break;
        }
    }

    if (where != BEFORE) {
        hx509_set_error_string(context, 0, HX509_PARSING_KEY_FAILED,
                               "File ends before end of PEM end tag");
        ret = HX509_PARSING_KEY_FAILED;
    }
    if (data)
        free(data);
    if (type)
        free(type);
    if (headers)
        hx509_pem_free_header(headers);

    return ret;
}