RetroShare/openpgpsdk/src/openpgpsdk/readerwriter.c

/*
 * Copyright (c) 2005-2008 Nominet UK (www.nic.uk)
 * All rights reserved.
 * Contributors: Ben Laurie, Rachel Willmer. The Contributors have asserted
 * their moral rights under the UK Copyright Design and Patents Act 1988 to
 * be recorded as the authors of this copyright work.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. 
 * 
 * You may obtain a copy of the License at 
 *     http://www.apache.org/licenses/LICENSE-2.0 
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * 
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <fcntl.h>
#ifndef WIN32
#include <unistd.h>
#include <termios.h>
#else
#include <direct.h>
#endif
#include <assert.h>
#include <string.h>
#include <stdio.h>

#include <openpgpsdk/readerwriter.h>
#include <openpgpsdk/callback.h>
#include <openpgpsdk/opsdir.h>

#include "parse_local.h"

#ifdef WIN32
#include <conio.h>
#include <stdio.h>

#define PASS_MAX 512

char *getpass (const char *prompt)
{
    static char getpassbuf [PASS_MAX + 1];
    size_t i = 0;
    int c;

    if (prompt) {
        fputs (prompt, stderr);
        fflush (stderr);
    }

    for (;;) {
        c = _getch ();
        if (c == '\r') {
            getpassbuf [i] = '\0';
            break;
        }
        else if (i < PASS_MAX) {
            getpassbuf[i++] = c;
        }

        if (i >= PASS_MAX) {
            getpassbuf [i] = '\0';
            break;
        }
    }

    if (prompt) {
        fputs ("\r\n", stderr);
        fflush (stderr);
    }

    return getpassbuf;
}
#endif

/**
 \ingroup Core_Writers
 \brief Create and initialise cinfo and mem; Set for writing to mem
 \param cinfo Address where new cinfo pointer will be set
 \param mem Address when new mem pointer will be set
 \param bufsz Initial buffer size (will automatically be increased when necessary)
 \note It is the caller's responsiblity to free cinfo and mem.
 \sa ops_teardown_memory_write()
*/
void ops_setup_memory_write(ops_create_info_t **cinfo, ops_memory_t **mem, size_t bufsz)
    {
    /*
     * initialise needed structures for writing to memory
     */

    *cinfo=ops_create_info_new();
    *mem=ops_memory_new();

    ops_memory_init(*mem,bufsz);

    ops_writer_set_memory(*cinfo,*mem);
    }

/**
   \ingroup Core_Writers
   \brief Closes writer and frees cinfo and mem
   \param cinfo
   \param mem
   \sa ops_setup_memory_write()
*/
void ops_teardown_memory_write(ops_create_info_t *cinfo, ops_memory_t *mem)
    {
    ops_writer_close(cinfo); // new
    ops_create_info_delete(cinfo);
    ops_memory_free(mem);
    }

/**
   \ingroup Core_Readers
   \brief Create parse_info and sets to read from memory
   \param pinfo Address where new parse_info will be set
   \param mem Memory to read from
   \param arg Reader-specific arg
   \param callback Callback to use with reader
   \param accumulate Set if we need to accumulate as we read. (Usually false unless doing signature verification)
   \note It is the caller's responsiblity to free parse_info
   \sa ops_teardown_memory_read()
*/
void ops_setup_memory_read(ops_parse_info_t **pinfo, ops_memory_t *mem,
                           void* arg,
                           ops_parse_cb_return_t callback(const ops_parser_content_t *, ops_parse_cb_info_t *),
                           ops_boolean_t accumulate)
    {
    /*
     * initialise needed uctures for reading
     */

    *pinfo=ops_parse_info_new();
    ops_parse_cb_set(*pinfo,callback,arg);
    ops_reader_set_memory(*pinfo,
                          ops_memory_get_data(mem),
                          ops_memory_get_length(mem));

    if (accumulate)
        (*pinfo)->rinfo.accumulate=ops_true;
    }

/**
   \ingroup Core_Readers
   \brief Frees pinfo and mem
   \param pinfo
   \param mem
   \sa ops_setup_memory_read()
*/
void ops_teardown_memory_read(ops_parse_info_t *pinfo, ops_memory_t *mem)
    {
    ops_parse_info_delete(pinfo);
    ops_memory_free(mem);
    }

/**
 \ingroup Core_Writers
 \brief Create and initialise cinfo and mem; Set for writing to file
 \param cinfo Address where new cinfo pointer will be set
 \param filename File to write to
 \param allow_overwrite Allows file to be overwritten, if set.
 \return Newly-opened file descriptor
 \note It is the caller's responsiblity to free cinfo and to close fd.
 \sa ops_teardown_file_write()
*/
int ops_setup_file_write(ops_create_info_t **cinfo, const char* filename, ops_boolean_t allow_overwrite)
    {
    int fd=0;
    int flags=0;

    /*
     * initialise needed structures for writing to file
     */

    flags=O_WRONLY | O_CREAT;
    if (allow_overwrite==ops_true)
        flags |= O_TRUNC;
    else
        flags |= O_EXCL;
    flags |= O_BINARY;

    fd=ops_open(filename, flags, 0600);
    if(fd < 0)
        {
        perror(filename);
        return fd;
        }
    
    *cinfo=ops_create_info_new();

    ops_writer_set_fd(*cinfo,fd);

    return fd;
    }

/**
   \ingroup Core_Writers
   \brief Closes writer, frees info, closes fd
   \param cinfo
   \param fd 
*/
void ops_teardown_file_write(ops_create_info_t *cinfo, int fd)
    {
    ops_writer_close(cinfo);
    close(fd);
    ops_create_info_delete(cinfo);
    }

/**
   \ingroup Core_Writers
   \brief As ops_setup_file_write, but appends to file
*/
int ops_setup_file_append(ops_create_info_t **cinfo, const char* filename)
    {
    int fd;
    /*
     * initialise needed structures for writing to file
     */

    fd=ops_open(filename,O_WRONLY | O_APPEND | O_BINARY | O_CREAT, 0600);

    if(fd < 0)
        {
        perror(filename);
        return fd;
        }
    
    *cinfo=ops_create_info_new();

    ops_writer_set_fd(*cinfo,fd);

    return fd;
    }

/**
   \ingroup Core_Writers
   \brief As ops_teardown_file_write()
*/
void ops_teardown_file_append(ops_create_info_t *cinfo, int fd)
    {
    ops_teardown_file_write(cinfo,fd);
    }

/**
   \ingroup Core_Readers
   \brief Creates parse_info, opens file, and sets to read from file
   \param pinfo Address where new parse_info will be set
   \param filename Name of file to read
   \param arg Reader-specific arg
   \param callback Callback to use when reading
   \param accumulate Set if we need to accumulate as we read. (Usually false unless doing signature verification)
   \note It is the caller's responsiblity to free parse_info and to close fd
   \sa ops_teardown_file_read()
*/

int ops_setup_file_read(ops_parse_info_t **pinfo, const char *filename,
                        void* arg,
                        ops_parse_cb_return_t callback(const ops_parser_content_t *, ops_parse_cb_info_t *),
                        ops_boolean_t accumulate)
    {
    int fd=0;
    /*
     * initialise needed structures for reading
     */

    fd=ops_open(filename,O_RDONLY | O_BINARY, 0);

    if (fd < 0)
        {
        perror(filename);
        return fd;
        }

    *pinfo=ops_parse_info_new();
    ops_parse_cb_set(*pinfo,callback,arg);
    ops_reader_set_fd(*pinfo,fd);

    if (accumulate)
        (*pinfo)->rinfo.accumulate=ops_true;

    return fd;
    }

/**
   \ingroup Core_Readers
   \brief Frees pinfo and closes fd
   \param pinfo
   \param fd
   \sa ops_setup_file_read()
*/
void ops_teardown_file_read(ops_parse_info_t *pinfo, int fd)
    {
    close(fd);
    ops_parse_info_delete(pinfo);
    }

ops_parse_cb_return_t
callback_literal_data(const ops_parser_content_t *content_,ops_parse_cb_info_t *cbinfo)
    {
    ops_parser_content_union_t* content=(ops_parser_content_union_t *)&content_->content;

    OPS_USED(cbinfo);

    //    ops_print_packet(content_);

    // Read data from packet into static buffer
    switch(content_->tag)
        {
    case OPS_PTAG_CT_LITERAL_DATA_BODY:
        // if writer enabled, use it
        if (cbinfo->cinfo)
            {
            ops_write(content->literal_data_body.data,
                      content->literal_data_body.length,
                      cbinfo->cinfo);
            }
        /*
        ops_memory_add(mem_literal_data,
                       content->literal_data_body.data,
                       content->literal_data_body.length);
        */
        break;

    case OPS_PTAG_CT_LITERAL_DATA_HEADER:
        // ignore
        break;

    default:
        //        return callback_general(content_,cbinfo);
        break;
        }

    return OPS_RELEASE_MEMORY;
    }
 
ops_parse_cb_return_t
callback_pk_session_key(const ops_parser_content_t *content_,ops_parse_cb_info_t *cbinfo)
    {
    ops_parser_content_union_t* content=(ops_parser_content_union_t *)&content_->content;
    
    OPS_USED(cbinfo);

    //    ops_print_packet(content_);
    
    // Read data from packet into static buffer
    switch(content_->tag)
        {
    case OPS_PTAG_CT_PK_SESSION_KEY:
		//	printf ("OPS_PTAG_CT_PK_SESSION_KEY\n");
        assert(cbinfo->cryptinfo.keyring);
        cbinfo->cryptinfo.keydata=ops_keyring_find_key_by_id(cbinfo->cryptinfo.keyring,
                                             content->pk_session_key.key_id);
        if(!cbinfo->cryptinfo.keydata)
            break;
        break;

    default:
        //        return callback_general(content_,cbinfo);
        break;
        }

    return OPS_RELEASE_MEMORY;
    }

/**
 \ingroup Core_Callbacks

\brief Callback to get secret key, decrypting if necessary.

@verbatim
 This callback does the following:
 * finds the session key in the keyring
 * gets a passphrase if required
 * decrypts the secret key, if necessary
 * sets the secret_key in the content struct
@endverbatim
*/

ops_parse_cb_return_t
callback_cmd_get_secret_key(const ops_parser_content_t *content_,ops_parse_cb_info_t *cbinfo)
{
	ops_parser_content_union_t* content=(ops_parser_content_union_t *)&content_->content;
	const ops_secret_key_t *secret;
	ops_parser_content_t pc;

	OPS_USED(cbinfo);

	//    ops_print_packet(content_);

	switch(content_->tag)
	{
		case OPS_PARSER_CMD_GET_SECRET_KEY:
			cbinfo->cryptinfo.keydata=ops_keyring_find_key_by_id(cbinfo->cryptinfo.keyring,content->get_secret_key.pk_session_key->key_id);
			if (!cbinfo->cryptinfo.keydata || !ops_is_key_secret(cbinfo->cryptinfo.keydata))
				return 0;

			/* now get the key from the data */
			secret=ops_get_secret_key_from_data(cbinfo->cryptinfo.keydata);
			int tag_to_use = OPS_PARSER_CMD_GET_SK_PASSPHRASE ;
			int nbtries = 0 ;

			while( (!secret) && nbtries++ < 3)
			{
				if (!cbinfo->cryptinfo.passphrase)
				{
					memset(&pc,'\0',sizeof pc);
					pc.content.secret_key_passphrase.passphrase=&cbinfo->cryptinfo.passphrase;
					CB(cbinfo,tag_to_use,&pc);
					if (!cbinfo->cryptinfo.passphrase)
					{
						fprintf(stderr,"can't get passphrase\n");
						assert(0);
					}
				}
				/* then it must be encrypted */
				secret=ops_decrypt_secret_key_from_data(cbinfo->cryptinfo.keydata,cbinfo->cryptinfo.passphrase);

				free(cbinfo->cryptinfo.passphrase) ;
				cbinfo->cryptinfo.passphrase = NULL ;
				tag_to_use = OPS_PARSER_CMD_GET_SK_PASSPHRASE_PREV_WAS_BAD ;
			}

			if(!secret)
				return 0 ;

			*content->get_secret_key.secret_key=secret;
			break;

		default:
			//        return callback_general(content_,cbinfo);
			break;
	}

	return OPS_RELEASE_MEMORY;
}

char *ops_get_passphrase(void)
    {
    return ops_malloc_passphrase(getpass("Passphrase: "));
    }

char *ops_malloc_passphrase(char *pp)
    {
    char *passphrase;
    size_t n;

    n=strlen(pp);
    passphrase=malloc(n+1);
    strncpy(passphrase,pp,n+1);

    return passphrase;
    }

/**
 \ingroup HighLevel_Callbacks
 \brief Callback to use when you need to prompt user for passphrase
 \param content_
 \param cbinfo
*/
ops_parse_cb_return_t
callback_cmd_get_passphrase_from_cmdline(const ops_parser_content_t *content_,ops_parse_cb_info_t *cbinfo)
    {
    ops_parser_content_union_t* content=(ops_parser_content_union_t *)&content_->content;

    OPS_USED(cbinfo);

//    ops_print_packet(content_);

    switch(content_->tag)
        {
    case OPS_PARSER_CMD_GET_SK_PASSPHRASE:
        *(content->secret_key_passphrase.passphrase)=ops_get_passphrase();
        return OPS_KEEP_MEMORY;
        break;
        
    default:
        //        return callback_general(content_,cbinfo);
        break;
	}
    
    return OPS_RELEASE_MEMORY;
    }

ops_boolean_t ops_reader_set_accumulate(ops_parse_info_t* pinfo, ops_boolean_t state)
    {
    pinfo->rinfo.accumulate=state;
    return state;
    }

// EOF