zip_source_pkware_encode.c File Reference

#include <stdlib.h>
#include <string.h>
#include "zipint.h"

Go to the source code of this file.

Classes
struct	trad_pkware

Functions
static int	encrypt_header (zip_source_t *, struct trad_pkware *)
static zip_int64_t	pkware_encrypt (zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t)
static void	trad_pkware_free (struct trad_pkware *)
static struct trad_pkware *	trad_pkware_new (const char *password, zip_error_t *error)
zip_source_t *	zip_source_pkware_encode (zip_t *za, zip_source_t *src, zip_uint16_t em, int flags, const char *password)

Function Documentation

encrypt_header()

static int encrypt_header ( zip_source_t *  src, struct trad_pkware *  ctx  )

static

Definition at line 83 of file zip_source_pkware_encode.c.

                                                           {
    struct zip_stat st;
    unsigned short dostime, dosdate;
    zip_uint8_t *header;
 
    if (zip_source_stat(src, &st) != 0) {
        _zip_error_set_from_source(&ctx->error, src);
        return -1;
    }
 
    _zip_u2d_time(st.mtime, &dostime, &dosdate);
 
    if ((ctx->buffer = _zip_buffer_new(NULL, ZIP_CRYPTO_PKWARE_HEADERLEN)) == NULL) {
        zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
        return -1;
    }
 
    header = _zip_buffer_data(ctx->buffer);
 
    /* generate header from random bytes and mtime
       see appnote.iz, XIII. Decryption, Step 2, last paragraph */
    if (!zip_secure_random(header, ZIP_CRYPTO_PKWARE_HEADERLEN - 1)) {
        zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0);
        _zip_buffer_free(ctx->buffer);
        ctx->buffer = NULL;
        return -1;
    }
    header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] = (zip_uint8_t)((dostime >> 8) & 0xff);
 
    _zip_pkware_encrypt(&ctx->keys, header, header, ZIP_CRYPTO_PKWARE_HEADERLEN);
 
    return 0;
}

References _zip_buffer_data(), _zip_buffer_free(), _zip_buffer_new(), _zip_error_set_from_source(), _zip_pkware_encrypt(), _zip_u2d_time(), ctx::error, header, zip_stat::mtime, NULL, src, ZIP_CRYPTO_PKWARE_HEADERLEN, ZIP_ER_INTERNAL, ZIP_ER_MEMORY, zip_error_set(), zip_secure_random(), and zip_source_stat().

Referenced by pkware_encrypt().

pkware_encrypt()

static zip_int64_t pkware_encrypt ( zip_source_t *  src, void *  ud, void *  data, zip_uint64_t  length, zip_source_cmd_t  cmd  )

static

Definition at line 119 of file zip_source_pkware_encode.c.

                                                                                                   {
    struct trad_pkware *ctx;
    zip_int64_t n;
    zip_uint64_t buffer_n;
 
    ctx = (struct trad_pkware *)ud;
 
    switch (cmd) {
    case ZIP_SOURCE_OPEN:
        ctx->eof = false;
 
        /* initialize keys */
        _zip_pkware_keys_reset(&ctx->keys);
        _zip_pkware_encrypt(&ctx->keys, NULL, (const zip_uint8_t *)ctx->password, strlen(ctx->password));
 
        if (encrypt_header(src, ctx) < 0) {
            return -1;
        }
        return 0;
 
    case ZIP_SOURCE_READ:
        buffer_n = 0;
 
        if (ctx->buffer) {
            /* write header values to data */
            buffer_n = _zip_buffer_read(ctx->buffer, data, length);
            data = (zip_uint8_t *)data + buffer_n;
            length -= buffer_n;
 
            if (_zip_buffer_eof(ctx->buffer)) {
                _zip_buffer_free(ctx->buffer);
                ctx->buffer = NULL;
            }
        }
 
        if (ctx->eof) {
            return (zip_int64_t)buffer_n;
        }
 
        if ((n = zip_source_read(src, data, length)) < 0) {
            _zip_error_set_from_source(&ctx->error, src);
            return -1;
        }
 
        _zip_pkware_encrypt(&ctx->keys, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n);
 
        if ((zip_uint64_t)n < length) {
            ctx->eof = true;
        }
 
        return (zip_int64_t)buffer_n + n;
 
    case ZIP_SOURCE_CLOSE:
        _zip_buffer_free(ctx->buffer);
        ctx->buffer = NULL;
        return 0;
 
    case ZIP_SOURCE_STAT: {
        zip_stat_t *st;
 
        st = (zip_stat_t *)data;
        st->encryption_method = ZIP_EM_TRAD_PKWARE;
        st->valid |= ZIP_STAT_ENCRYPTION_METHOD;
        if (st->valid & ZIP_STAT_COMP_SIZE) {
            st->comp_size += ZIP_CRYPTO_PKWARE_HEADERLEN;
        }
 
        return 0;
    }
 
    case ZIP_SOURCE_GET_FILE_ATTRIBUTES: {
        zip_file_attributes_t *attributes = (zip_file_attributes_t *)data;
        if (length < sizeof(*attributes)) {
            zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
            return -1;
        }
        attributes->valid |= ZIP_FILE_ATTRIBUTES_VERSION_NEEDED;
        attributes->version_needed = 20;
 
        return 0;
    }
 
    case ZIP_SOURCE_SUPPORTS:
        return zip_source_make_command_bitmap(ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, ZIP_SOURCE_CLOSE, ZIP_SOURCE_STAT, ZIP_SOURCE_ERROR, ZIP_SOURCE_FREE, ZIP_SOURCE_GET_FILE_ATTRIBUTES, -1);
 
    case ZIP_SOURCE_ERROR:
        return zip_error_to_data(&ctx->error, data, length);
 
    case ZIP_SOURCE_FREE:
        trad_pkware_free(ctx);
        return 0;
 
    default:
        zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
        return -1;
    }
}

References _zip_buffer_eof(), _zip_buffer_free(), _zip_buffer_read(), _zip_error_set_from_source(), _zip_pkware_encrypt(), _zip_pkware_keys_reset(), cmd, zip_stat::comp_size, encrypt_header(), zip_stat::encryption_method, ctx::error, length, n, NULL, src, trad_pkware_free(), zip_stat::valid, zip_file_attributes::valid, zip_file_attributes::version_needed, ZIP_CRYPTO_PKWARE_HEADERLEN, ZIP_EM_TRAD_PKWARE, ZIP_ER_INVAL, zip_error_set(), zip_error_to_data(), ZIP_FILE_ATTRIBUTES_VERSION_NEEDED, ZIP_SOURCE_CLOSE, ZIP_SOURCE_ERROR, ZIP_SOURCE_FREE, ZIP_SOURCE_GET_FILE_ATTRIBUTES, zip_source_make_command_bitmap(), ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, zip_source_read(), ZIP_SOURCE_STAT, ZIP_SOURCE_SUPPORTS, ZIP_STAT_COMP_SIZE, and ZIP_STAT_ENCRYPTION_METHOD.

Referenced by zip_source_pkware_encode().

trad_pkware_free()

static void trad_pkware_free ( struct trad_pkware *  ctx )

static

Definition at line 240 of file zip_source_pkware_encode.c.

                                          {
    if (ctx == NULL) {
        return;
    }
 
    free(ctx->password);
    _zip_buffer_free(ctx->buffer);
    zip_error_fini(&ctx->error);
    free(ctx);
}

References _zip_buffer_free(), ctx::error, free(), NULL, and zip_error_fini().

Referenced by pkware_encrypt(), and zip_source_pkware_encode().

trad_pkware_new()

static struct trad_pkware * trad_pkware_new ( const char *  password, zip_error_t *  error  )

static

Definition at line 219 of file zip_source_pkware_encode.c.

                                                          {
    struct trad_pkware *ctx;
 
    if ((ctx = (struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) {
        zip_error_set(error, ZIP_ER_MEMORY, 0);
        return NULL;
    }
 
    if ((ctx->password = strdup(password)) == NULL) {
        zip_error_set(error, ZIP_ER_MEMORY, 0);
        free(ctx);
        return NULL;
    }
    ctx->buffer = NULL;
    zip_error_init(&ctx->error);
 
    return ctx;
}

References ctx::error, error(), free(), malloc(), NULL, trad_pkware::password, strdup(), ZIP_ER_MEMORY, zip_error_init(), and zip_error_set().

Referenced by zip_source_pkware_encode().

zip_source_pkware_encode()

zip_source_t* zip_source_pkware_encode	(	zip_t *	za,
		zip_source_t *	src,
		zip_uint16_t	em,
		int	flags,
		const char *	password
	)

Definition at line 56 of file zip_source_pkware_encode.c.

                                                                                                         {
    struct trad_pkware *ctx;
    zip_source_t *s2;
 
    if (password == NULL || src == NULL || em != ZIP_EM_TRAD_PKWARE) {
        zip_error_set(&za->error, ZIP_ER_INVAL, 0);
        return NULL;
    }
    if (!(flags & ZIP_CODEC_ENCODE)) {
        zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0);
        return NULL;
    }
 
    if ((ctx = trad_pkware_new(password, &za->error)) == NULL) {
        return NULL;
    }
 
    if ((s2 = zip_source_layered(za, src, pkware_encrypt, ctx)) == NULL) {
        trad_pkware_free(ctx);
        return NULL;
    }
 
    return s2;
}

References zip::error, flags, NULL, trad_pkware::password, pkware_encrypt(), s2, src, trad_pkware_free(), trad_pkware_new(), za, ZIP_CODEC_ENCODE, ZIP_EM_TRAD_PKWARE, ZIP_ER_ENCRNOTSUPP, ZIP_ER_INVAL, zip_error_set(), and zip_source_layered().

Referenced by _zip_get_encryption_implementation().