fwknop/lib/fko_util.c

373 lines
10 KiB
C

/*
*****************************************************************************
*
* File: fko_util.c
*
* Author: Michael Rash
*
* Purpose: Provide a set of common utility functions that fwknop can use.
*
* Copyright 2012 Michael Rash (mbr@cipherdyne.org)
*
* License (GNU Public License):
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
*****************************************************************************
*/
#include "fko_common.h"
#include "fko.h"
#include "fko_util.h"
#include <errno.h>
/* Validate encoded message length
*/
int
is_valid_encoded_msg_len(const int len)
{
if(len < MIN_SPA_ENCODED_MSG_SIZE || len >= MAX_SPA_ENCODED_MSG_SIZE)
return(0);
return(1);
}
/* Convert a digest_type string to its integer value.
*/
short
digest_strtoint(const char *dt_str)
{
if(strcasecmp(dt_str, "md5") == 0)
return(FKO_DIGEST_MD5);
else if(strcasecmp(dt_str, "sha1") == 0)
return(FKO_DIGEST_SHA1);
else if(strcasecmp(dt_str, "sha256") == 0)
return(FKO_DIGEST_SHA256);
else if(strcasecmp(dt_str, "sha384") == 0)
return(FKO_DIGEST_SHA384);
else if(strcasecmp(dt_str, "sha512") == 0)
return(FKO_DIGEST_SHA512);
else
return(-1);
}
/**
* \brief Return a digest string according to a digest integer value
*
* This function checks the digest integer is valid, and write the digest
* string associated.
*
* \param digest Digest inetger value (FKO_DIGEST_MD5, FKO_DIGEST_SHA1 ...)
* \param digest_str Buffer to write the digest string
* \param digest_size size of the digest string buffer
*
* \return -1 if the digest integer value is not supported, 0 otherwise
*/
short
digest_inttostr(int digest, char* digest_str, size_t digest_size)
{
short digest_not_valid = 0;
memset(digest_str, 0, digest_size);
switch (digest)
{
case FKO_DIGEST_MD5:
strlcpy(digest_str, "MD5", digest_size);
break;
case FKO_DIGEST_SHA1:
strlcpy(digest_str, "SHA1", digest_size);
break;
case FKO_DIGEST_SHA256:
strlcpy(digest_str, "SHA256", digest_size);
break;
case FKO_DIGEST_SHA384:
strlcpy(digest_str, "SHA384", digest_size);
break;
case FKO_DIGEST_SHA512:
strlcpy(digest_str, "SHA512", digest_size);
break;
default:
strlcpy(digest_str, "Unknown", digest_size);
digest_not_valid = -1;
break;
}
return digest_not_valid;
}
short
hmac_digest_strtoint(const char *dt_str)
{
if(strcasecmp(dt_str, "md5") == 0)
return(FKO_HMAC_MD5);
else if(strcasecmp(dt_str, "sha1") == 0)
return(FKO_HMAC_SHA1);
else if(strcasecmp(dt_str, "sha256") == 0)
return(FKO_HMAC_SHA256);
else if(strcasecmp(dt_str, "sha384") == 0)
return(FKO_HMAC_SHA384);
else if(strcasecmp(dt_str, "sha512") == 0)
return(FKO_HMAC_SHA512);
else
return(-1);
}
/* Return encryption type string representation
*/
const char *
enc_type_inttostr(const int type)
{
if(type == FKO_ENC_MODE_UNKNOWN)
return("Unknown encryption type");
else if(type == FKO_ENCRYPTION_RIJNDAEL)
return("Rijndael");
else if(type == FKO_ENCRYPTION_GPG)
return("GPG");
return("Unknown encryption type");
}
/* Return message type string representation
*/
const char *
msg_type_inttostr(const int type)
{
if(type == FKO_COMMAND_MSG)
return("Command msg");
else if(type == FKO_ACCESS_MSG)
return("Access msg");
else if(type == FKO_NAT_ACCESS_MSG)
return("NAT access msg");
else if(type == FKO_CLIENT_TIMEOUT_ACCESS_MSG)
return("Client timeout access msg");
else if(type == FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG)
return("Client timeout NAT access msg");
else if(type == FKO_LOCAL_NAT_ACCESS_MSG)
return("Local NAT access msg");
else if(type == FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG)
return("Client timeout local NAT access msg");
return("Unknown message type");
}
/**
* \brief Return a hmac digest string according to a hmac digest integer value
*
* This function checks if the digest integer is valid, and write the digest
* string associated.
*
* \param digest Digest inetger value (FKO_HMAC_MD5, FKO_HMAC_SHA1 ...)
* \param digest_str Buffer to write the digest string
* \param digest_size size of the digest string buffer
*
* \return -1 if the digest integer value is not supported, 0 otherwise
*/
short
hmac_digest_inttostr(int digest, char* digest_str, size_t digest_size)
{
short digest_not_valid = 0;
memset(digest_str, 0, digest_size);
switch (digest)
{
case FKO_HMAC_MD5:
strlcpy(digest_str, "MD5", digest_size);
break;
case FKO_HMAC_SHA1:
strlcpy(digest_str, "SHA1", digest_size);
break;
case FKO_HMAC_SHA256:
strlcpy(digest_str, "SHA256", digest_size);
break;
case FKO_HMAC_SHA384:
strlcpy(digest_str, "SHA384", digest_size);
break;
case FKO_HMAC_SHA512:
strlcpy(digest_str, "SHA512", digest_size);
break;
default:
strlcpy(digest_str, "Unknown", digest_size);
digest_not_valid = -1;
break;
}
return digest_not_valid;
}
/* Validate plaintext input size
*/
int
is_valid_pt_msg_len(const int len)
{
if(len < MIN_SPA_PLAINTEXT_MSG_SIZE || len >= MAX_SPA_PLAINTEXT_MSG_SIZE)
return(0);
return(1);
}
/* Convert an encryption_mode string to its integer value.
*/
int
enc_mode_strtoint(const char *enc_mode_str)
{
if(strcasecmp(enc_mode_str, "cbc") == 0)
return(FKO_ENC_MODE_CBC);
else if(strcasecmp(enc_mode_str, "ecb") == 0)
return(FKO_ENC_MODE_ECB);
else if(strcasecmp(enc_mode_str, "cfb") == 0)
return(FKO_ENC_MODE_CFB);
else if(strcasecmp(enc_mode_str, "pcbc") == 0)
return(-1); /* not supported yet */
else if(strcasecmp(enc_mode_str, "ofb") == 0)
return(FKO_ENC_MODE_OFB);
else if(strcasecmp(enc_mode_str, "ctr") == 0)
return(FKO_ENC_MODE_CTR);
else if(strcasecmp(enc_mode_str, "legacy") == 0)
return(FKO_ENC_MODE_CBC_LEGACY_IV);
else
return(-1);
}
/**
* \brief Return an encryption mode string according to an enc_mode integer value
*
* This function checks if the encryption mode integer is valid, and write the
* encryption mode string associated.
*
* \param enc_mode Encryption mode inetger value (FKO_ENC_MODE_CBC, FKO_ENC_MODE_ECB ...)
* \param enc_mode_str Buffer to write the encryption mode string
* \param enc_mode_size size of the encryption mode string buffer
*
* \return -1 if the encryption mode integer value is not supported, 0 otherwise
*/
short
enc_mode_inttostr(int enc_mode, char* enc_mode_str, size_t enc_mode_size)
{
short enc_mode_not_valid = 0;
memset(enc_mode_str, 0, enc_mode_size);
switch (enc_mode)
{
case FKO_ENC_MODE_CBC :
strlcpy(enc_mode_str, "CBC", enc_mode_size);
break;
case FKO_ENC_MODE_ECB :
strlcpy(enc_mode_str, "ECB", enc_mode_size);
break;
case FKO_ENC_MODE_CFB :
strlcpy(enc_mode_str, "CFB", enc_mode_size);
break;
case FKO_ENC_MODE_PCBC :
//strlcpy(enc_mode_str, "PCBC", enc_mode_size);
enc_mode_not_valid = -1;
break;
case FKO_ENC_MODE_OFB :
strlcpy(enc_mode_str, "OFB", enc_mode_size);
break;
case FKO_ENC_MODE_CTR :
strlcpy(enc_mode_str, "CTR", enc_mode_size);
break;
case FKO_ENC_MODE_CBC_LEGACY_IV:
strlcpy(enc_mode_str, "CBC legacy IV", enc_mode_size);
break;
case FKO_ENC_MODE_ASYMMETRIC:
strlcpy(enc_mode_str, "Asymmetric", enc_mode_size);
break;
default:
enc_mode_not_valid = -1;
break;
}
return enc_mode_not_valid;
}
int
strtol_wrapper(const char * const str, const int min,
const int max, const int exit_upon_err, int *err)
{
int val;
errno = 0;
*err = FKO_SUCCESS;
val = strtol(str, (char **) NULL, 10);
if ((errno == ERANGE || (errno != 0 && val == 0)))
{
*err = errno;
if(exit_upon_err == EXIT_UPON_ERR)
{
perror("strtol");
fprintf(stderr, "[*] Value %d out of range %d - %d\n",
val, min, max);
exit(EXIT_FAILURE);
}
}
if(val < min)
{
*err = FKO_ERROR_INVALID_DATA;
if(exit_upon_err == EXIT_UPON_ERR)
{
fprintf(stderr, "[*] Value %d out of range %d - %d\n",
val, min, max);
exit(EXIT_FAILURE);
}
}
/* allow max == -1 to be an exception where we don't care about the
* maximum - note that the ERANGE check is still in place above
*/
if((max >= 0) && (val > max))
{
*err = FKO_ERROR_INVALID_DATA;
if(exit_upon_err == EXIT_UPON_ERR)
{
fprintf(stderr, "[*] Value %d out of range %d - %d\n",
val, min, max);
exit(EXIT_FAILURE);
}
}
return val;
}
#ifdef WIN32
/* Windows does not have strndup, so we well implement it here.
* This was the Public Domain C Library (PDCLib).
*/
char
*strndup( const char * s, size_t len )
{
char* ns = NULL;
if(s) {
ns = malloc(len + 1);
if(ns) {
ns[len] = 0;
// strncpy to be pedantic about modification in multithreaded
// applications
return strncpy(ns, s, len);
}
}
return ns;
}
#endif
/***EOF***/