static int
parse_username(char *tbuf, char **ndx, int *t_size, fko_ctx_t ctx)
{
if((*t_size = strcspn(*ndx, ":")) < 1)
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_MISSING);
if (*t_size > MAX_SPA_USERNAME_SIZE)
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_TOOBIG);
strlcpy(tbuf, *ndx, *t_size+1);
if(ctx->username != NULL)
free(ctx->username);
ctx->username = calloc(1, *t_size+1); /* Yes, more than we need */
if(ctx->username == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
if(b64_decode(tbuf, (unsigned char*)ctx->username) < 0)
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_DECODEFAIL);
if(validate_username(ctx->username) != FKO_SUCCESS)
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_VALIDFAIL);
*ndx += *t_size + 1;
return FKO_SUCCESS;
}
/* Get or Set the username for the fko context spa data.
*/
int
fko_set_username(fko_ctx_t ctx, const char * const spoof_user)
{
char *username = NULL;
int res = FKO_SUCCESS, is_user_heap_allocated=0;
#if HAVE_LIBFIU
fiu_return_on("fko_set_username_init", FKO_ERROR_CTX_NOT_INITIALIZED);
#endif
/* Must be initialized
*/
if(!CTX_INITIALIZED(ctx))
return FKO_ERROR_CTX_NOT_INITIALIZED;
/* If spoof_user was not passed in, check for a SPOOF_USER enviroment
* variable. If it is set, use its value.
*/
if(spoof_user != NULL && spoof_user[0] != '\0')
{
#if HAVE_LIBFIU
fiu_return_on("fko_set_username_strdup", FKO_ERROR_MEMORY_ALLOCATION);
#endif
username = strdup(spoof_user);
if(username == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
is_user_heap_allocated = 1;
}
else
username = getenv("SPOOF_USER");
/* Try to get the username from the system.
*/
if(username == NULL)
{
/* Since we've already tried looking at an env variable, try
* LOGNAME next (and the cuserid() man page recommends this)
*/
if((username = getenv("LOGNAME")) == NULL)
{
#ifdef _XOPEN_SOURCE
/* cuserid will return the effective user (i.e. su or setuid).
*/
username = cuserid(NULL);
#else
username = getlogin();
#endif
/* if we still didn't get a username, continue falling back
*/
if(username == NULL)
{
if((username = getenv("USER")) == NULL)
{
username = strdup("NO_USER");
if(username == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
is_user_heap_allocated = 1;
}
}
}
}
/* Truncate the username if it is too long.
*/
if(strnlen(username, MAX_SPA_USERNAME_SIZE) == MAX_SPA_USERNAME_SIZE)
*(username + MAX_SPA_USERNAME_SIZE - 1) = '\0';
if((res = validate_username(username)) != FKO_SUCCESS)
{
if(is_user_heap_allocated == 1)
free(username);
#if HAVE_LIBFIU
fiu_return_on("fko_set_username_valuser", FKO_ERROR_INVALID_DATA);
#endif
return res;
}
/* Just in case this is a subsquent call to this function. We
* do not want to be leaking memory.
*/
if(ctx->username != NULL)
free(ctx->username);
ctx->username = strdup(username);
ctx->state |= FKO_DATA_MODIFIED;
if(is_user_heap_allocated == 1)
free(username);
if(ctx->username == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
return(FKO_SUCCESS);
}
/* Decode the encoded SPA data.
*/
int
fko_decode_spa_data(fko_ctx_t ctx)
{
char *tbuf, *ndx, *tmp;
int t_size, i, is_err;
if (! is_valid_encoded_msg_len(ctx->encoded_msg_len))
return(FKO_ERROR_INVALID_DATA_DECODE_MSGLEN_VALIDFAIL);
/* Make sure there are no non-ascii printable chars
*/
for (i=0; i < (int)strnlen(ctx->encoded_msg, MAX_SPA_ENCODED_MSG_SIZE); i++)
if(isprint(ctx->encoded_msg[i]) == 0)
return(FKO_ERROR_INVALID_DATA_DECODE_NON_ASCII);
/* Make sure there are enough fields in the SPA packet
* delimited with ':' chars
*/
ndx = ctx->encoded_msg;
for (i=0; i < MAX_SPA_FIELDS; i++)
{
if ((tmp = strchr(ndx, ':')) == NULL)
break;
ndx = tmp;
ndx++;
}
if (i < MIN_SPA_FIELDS)
return(FKO_ERROR_INVALID_DATA_DECODE_LT_MIN_FIELDS);
t_size = strnlen(ndx, SHA512_B64_LEN+1);
switch(t_size)
{
case MD5_B64_LEN:
ctx->digest_type = FKO_DIGEST_MD5;
ctx->digest_len = MD5_B64_LEN;
break;
case SHA1_B64_LEN:
ctx->digest_type = FKO_DIGEST_SHA1;
ctx->digest_len = SHA1_B64_LEN;
break;
case SHA256_B64_LEN:
ctx->digest_type = FKO_DIGEST_SHA256;
ctx->digest_len = SHA256_B64_LEN;
break;
case SHA384_B64_LEN:
ctx->digest_type = FKO_DIGEST_SHA384;
ctx->digest_len = SHA384_B64_LEN;
break;
case SHA512_B64_LEN:
ctx->digest_type = FKO_DIGEST_SHA512;
ctx->digest_len = SHA512_B64_LEN;
break;
default: /* Invalid or unsupported digest */
return(FKO_ERROR_INVALID_DIGEST_TYPE);
}
if (ctx->encoded_msg_len - t_size < 0)
return(FKO_ERROR_INVALID_DATA_DECODE_ENC_MSG_LEN_MT_T_SIZE);
if(ctx->digest != NULL)
free(ctx->digest);
/* Copy the digest into the context and terminate the encoded data
* at that point so the original digest is not part of the
* encoded string.
*/
ctx->digest = strdup(ndx);
if(ctx->digest == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Zero out the rest of the encoded_msg bucket...
*/
bzero((ndx-1), t_size);
ctx->encoded_msg_len -= t_size+1;
/* Make a tmp bucket for processing base64 encoded data and
* other general use.
*/
tbuf = malloc(FKO_ENCODE_TMP_BUF_SIZE);
if(tbuf == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Can now verify the digest.
*/
switch(ctx->digest_type)
{
case FKO_DIGEST_MD5:
md5_base64(tbuf, (unsigned char*)ctx->encoded_msg, ctx->encoded_msg_len);
break;
case FKO_DIGEST_SHA1:
sha1_base64(tbuf, (unsigned char*)ctx->encoded_msg, ctx->encoded_msg_len);
break;
case FKO_DIGEST_SHA256:
sha256_base64(tbuf, (unsigned char*)ctx->encoded_msg, ctx->encoded_msg_len);
break;
case FKO_DIGEST_SHA384:
sha384_base64(tbuf, (unsigned char*)ctx->encoded_msg, ctx->encoded_msg_len);
break;
case FKO_DIGEST_SHA512:
sha512_base64(tbuf, (unsigned char*)ctx->encoded_msg, ctx->encoded_msg_len);
break;
}
/* We give up here if the computed digest does not match the
* digest in the message data.
*/
if(constant_runtime_cmp(ctx->digest, tbuf, t_size) != 0)
{
free(tbuf);
return(FKO_ERROR_DIGEST_VERIFICATION_FAILED);
}
/* Now we will work through the encoded data and extract (and base64-
* decode where necessary), the SPA data fields and populate the context.
*/
ndx = ctx->encoded_msg;
/* The rand val data */
if((t_size = strcspn(ndx, ":")) < FKO_RAND_VAL_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_RAND_MISSING);
}
if(ctx->rand_val != NULL)
free(ctx->rand_val);
ctx->rand_val = calloc(1, FKO_RAND_VAL_SIZE+1);
if(ctx->rand_val == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
ctx->rand_val = strncpy(ctx->rand_val, ndx, FKO_RAND_VAL_SIZE);
/* Jump to the next field (username). We need to use the temp buffer
* for the base64 decode step.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_MISSING);
}
if (t_size > MAX_SPA_USERNAME_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_TOOBIG);
}
strlcpy(tbuf, ndx, t_size+1);
if(ctx->username != NULL)
free(ctx->username);
ctx->username = malloc(t_size+1); /* Yes, more than we need */
if(ctx->username == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
if(b64_decode(tbuf, (unsigned char*)ctx->username) < 0)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_DECODEFAIL);
}
if(validate_username(ctx->username) != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_USERNAME_VALIDFAIL);
}
/* Extract the timestamp value.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMESTAMP_MISSING);
}
if (t_size > MAX_SPA_TIMESTAMP_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMESTAMP_TOOBIG);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->timestamp = (unsigned int) strtol_wrapper(tbuf,
0, -1, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMESTAMP_DECODEFAIL);
}
/* Extract the version string.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_VERSION_MISSING);
}
if (t_size > MAX_SPA_VERSION_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_VERSION_TOOBIG);
}
if(ctx->version != NULL)
free(ctx->version);
ctx->version = malloc(t_size+1);
if(ctx->version == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
strlcpy(ctx->version, ndx, t_size+1);
/* Extract the message type value.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MSGTYPE_MISSING);
}
if (t_size > MAX_SPA_MESSAGE_TYPE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MSGTYPE_TOOBIG);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->message_type = strtol_wrapper(tbuf, 0,
FKO_LAST_MSG_TYPE, NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MSGTYPE_DECODEFAIL);
}
/* Extract the SPA message string.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MESSAGE_MISSING);
}
if (t_size > MAX_SPA_MESSAGE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MESSAGE_TOOBIG);
}
strlcpy(tbuf, ndx, t_size+1);
if(ctx->message != NULL)
free(ctx->message);
ctx->message = malloc(t_size+1); /* Yes, more than we need */
if(ctx->message == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
if(b64_decode(tbuf, (unsigned char*)ctx->message) < 0)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MESSAGE_DECODEFAIL);
}
if(ctx->message_type == FKO_COMMAND_MSG)
{
/* Require a message similar to: 1.2.3.4,<command>
*/
if(validate_cmd_msg(ctx->message) != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_MESSAGE_VALIDFAIL);
}
}
else
{
/* Require a message similar to: 1.2.3.4,tcp/22
*/
if(validate_access_msg(ctx->message) != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_ACCESS_VALIDFAIL);
}
}
/* Extract nat_access string if the message_type indicates so.
*/
if( ctx->message_type == FKO_NAT_ACCESS_MSG
|| ctx->message_type == FKO_LOCAL_NAT_ACCESS_MSG
|| ctx->message_type == FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG
|| ctx->message_type == FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG)
{
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_NATACCESS_MISSING);
}
if (t_size > MAX_SPA_MESSAGE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_NATACCESS_TOOBIG);
}
strlcpy(tbuf, ndx, t_size+1);
if(ctx->nat_access != NULL)
free(ctx->nat_access);
ctx->nat_access = malloc(t_size+1); /* Yes, more than we need */
if(ctx->nat_access == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
if(b64_decode(tbuf, (unsigned char*)ctx->nat_access) < 0)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_NATACCESS_DECODEFAIL);
}
if(validate_nat_access_msg(ctx->nat_access) != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_NATACCESS_VALIDFAIL);
}
}
/* Now look for a server_auth string.
*/
ndx += t_size + 1;
if((t_size = strlen(ndx)) > 0)
{
if (t_size > MAX_SPA_MESSAGE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_SRVAUTH_MISSING);
}
/* There is data, but what is it?
* If the message_type does not have a timeout, assume it is a
* server_auth field.
*/
if( ctx->message_type != FKO_CLIENT_TIMEOUT_ACCESS_MSG
&& ctx->message_type != FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG
&& ctx->message_type != FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG)
{
strlcpy(tbuf, ndx, t_size+1);
if(ctx->server_auth != NULL)
free(ctx->server_auth);
ctx->server_auth = malloc(t_size+1); /* Yes, more than we need */
if(ctx->server_auth == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
if(b64_decode(tbuf, (unsigned char*)ctx->server_auth) < 0)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_SRVAUTH_DECODEFAIL);
}
/* At this point we should be done.
*/
free(tbuf);
/* Call the context initialized.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
return(FKO_SUCCESS);
}
/* If we are here then we may still have a server_auth string,
* or a timeout, or both. So we look for a ':' delimiter. If
* it is there we have both, if not we check the message_type
* again.
*/
if(strchr(ndx, ':'))
{
t_size = strcspn(ndx, ":");
if (t_size > MAX_SPA_MESSAGE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_EXTRA_TOOBIG);
}
/* Looks like we have both, so assume this is the
*/
strlcpy(tbuf, ndx, t_size+1);
if(ctx->server_auth != NULL)
free(ctx->server_auth);
ctx->server_auth = malloc(t_size+1); /* Yes, more than we need */
if(ctx->server_auth == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
if(b64_decode(tbuf, (unsigned char*)ctx->server_auth) < 0)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_EXTRA_DECODEFAIL);
}
ndx += t_size + 1;
}
/* Now we look for a timeout value if one is supposed to be there.
*/
if( ctx->message_type == FKO_CLIENT_TIMEOUT_ACCESS_MSG
|| ctx->message_type == FKO_CLIENT_TIMEOUT_NAT_ACCESS_MSG
|| ctx->message_type == FKO_CLIENT_TIMEOUT_LOCAL_NAT_ACCESS_MSG)
{
if((t_size = strlen(ndx)) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMEOUT_MISSING);
}
if (t_size > MAX_SPA_MESSAGE_SIZE)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMEOUT_TOOBIG);
}
/* Should be a number only.
*/
if(strspn(ndx, "0123456789") != t_size)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMEOUT_VALIDFAIL);
}
ctx->client_timeout = (unsigned int) strtol_wrapper(ndx, 0,
(2 << 15), NO_EXIT_UPON_ERR, &is_err);
if(is_err != FKO_SUCCESS)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA_DECODE_TIMEOUT_DECODEFAIL);
}
}
}
/* Done with the tmp buffer.
*/
free(tbuf);
/* Call the context initialized.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
return(FKO_SUCCESS);
}
/* Set the SPA encryption type.
*/
int
fko_encode_spa_data(fko_ctx_t ctx)
{
int res, offset = 0;
char *tbuf;
/* Must be initialized
*/
if(!CTX_INITIALIZED(ctx))
return(FKO_ERROR_CTX_NOT_INITIALIZED);
/* Check prerequisites.
* --DSS XXX: Needs review. Also, we could make this more robust (or
* (at leaset expand the error reporting for the missing
* data).
*/
if( validate_username(ctx->username) != FKO_SUCCESS
|| ctx->version == NULL || strnlen(ctx->version, MAX_SPA_VERSION_SIZE) == 0
|| ctx->message == NULL || strnlen(ctx->message, MAX_SPA_MESSAGE_SIZE) == 0)
{
return(FKO_ERROR_INCOMPLETE_SPA_DATA);
}
if(ctx->message_type == FKO_NAT_ACCESS_MSG)
{
if(ctx->nat_access == NULL || strnlen(ctx->nat_access, MAX_SPA_MESSAGE_SIZE) == 0)
return(FKO_ERROR_INCOMPLETE_SPA_DATA);
}
/* Allocate our initial tmp buffer.
*/
tbuf = calloc(1, FKO_ENCODE_TMP_BUF_SIZE);
if(tbuf == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Put it together a piece at a time, starting with the rand val.
*/
strlcpy(tbuf, ctx->rand_val, FKO_ENCODE_TMP_BUF_SIZE);
/* Add the base64-encoded username.
*/
strlcat(tbuf, ":", FKO_ENCODE_TMP_BUF_SIZE);
if((res = append_b64(tbuf, ctx->username)) != FKO_SUCCESS)
{
free(tbuf);
return(res);
}
/* Add the timestamp.
*/
offset = strlen(tbuf);
sprintf(((char*)tbuf+offset), ":%u:", (unsigned int) ctx->timestamp);
/* Add the version string.
*/
strlcat(tbuf, ctx->version, FKO_ENCODE_TMP_BUF_SIZE);
/* Before we add the message type value, we will once again
* check for whether or not a client_timeout was specified
* since the message_type was set. If this is the case, then
* we want to adjust the message_type first. The easy way
* to do this is simply call fko_set_spa_client_timeout and set
* it to its current value. This will force a re-check and
* possible reset of the message type.
*
*/
fko_set_spa_client_timeout(ctx, ctx->client_timeout);
/* Add the message type value.
*/
offset = strlen(tbuf);
sprintf(((char*)tbuf+offset), ":%i:", ctx->message_type);
/* Add the base64-encoded SPA message.
*/
if((res = append_b64(tbuf, ctx->message)) != FKO_SUCCESS)
{
free(tbuf);
return(res);
}
/* If a nat_access message was given, add it to the SPA
* message.
*/
if(ctx->nat_access != NULL)
{
strlcat(tbuf, ":", FKO_ENCODE_TMP_BUF_SIZE);
if((res = append_b64(tbuf, ctx->nat_access)) != FKO_SUCCESS)
{
free(tbuf);
return(res);
}
}
/* If we have a server_auth field set. Add it here.
*
*/
if(ctx->server_auth != NULL)
{
strlcat(tbuf, ":", FKO_ENCODE_TMP_BUF_SIZE);
if((res = append_b64(tbuf, ctx->server_auth)) != FKO_SUCCESS)
{
free(tbuf);
return(res);
}
}
/* If a client timeout is specified and we are not dealing with a
* SPA command message, add the timeout here.
*/
if(ctx->client_timeout > 0 && ctx->message_type != FKO_COMMAND_MSG)
{
offset = strlen(tbuf);
sprintf(((char*)tbuf+offset), ":%i", ctx->client_timeout);
}
/* If encoded_msg is not null, then we assume it needs to
* be freed before re-assignment.
*/
if(ctx->encoded_msg != NULL)
free(ctx->encoded_msg);
/* Copy our encoded data into the context.
*/
ctx->encoded_msg = strdup(tbuf);
if(ctx->encoded_msg == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
/* At this point we can compute the digest for this SPA data.
*/
if((res = fko_set_spa_digest(ctx)) != FKO_SUCCESS)
{
free(tbuf);
return(res);
}
/* Here we can clear the modified flags on the SPA data fields.
*/
FKO_CLEAR_SPA_DATA_MODIFIED(ctx);
free(tbuf);
return(FKO_SUCCESS);
}
