/* Initialize an fko context with external (encrypted/encoded) data.
* This is used to create a context with the purpose of decoding
* and parsing the provided data into the context data.
*/
int
fko_new_with_data(fko_ctx_t *r_ctx, char *enc_msg, char *dec_key)
{
fko_ctx_t ctx;
int res = FKO_SUCCESS; /* Are we optimistic or what? */
ctx = calloc(1, sizeof *ctx);
if(ctx == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* First, add the data to the context.
*/
ctx->encrypted_msg = strdup(enc_msg);
if(ctx->encrypted_msg == NULL)
{
free(ctx);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
/* Consider it initialized here.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
/* If a decryption password is provided, go ahead and decrypt and
* decode.
*/
if(dec_key != NULL)
{
res = fko_decrypt_spa_data(ctx, dec_key);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
*r_ctx = NULL; /* Make sure the caller ctx is null just in case */
return(res);
}
}
#if HAVE_LIBGPGME
/* Set gpg signature verify on.
*/
ctx->verify_gpg_sigs = 1;
#endif /* HAVE_LIBGPGME */
*r_ctx = ctx;
return(res);
}
/* Decode the encoded SPA data.
*/
int
fko_decode_spa_data(fko_ctx_t ctx)
{
char *tbuf, *ndx;
int t_size, i, res;
/* Array of function pointers to SPA field parsing functions
*/
int (*field_parser[FIELD_PARSERS])(char *tbuf, char **ndx, int *t_size, fko_ctx_t ctx)
= { parse_rand_val, /* Extract random value */
parse_username, /* Extract username */
parse_timestamp, /* Client timestamp */
parse_version, /* SPA version */
parse_msg_type, /* SPA msg type */
parse_msg, /* SPA msg string */
parse_nat_msg, /* SPA NAT msg string */
parse_server_auth, /* optional server authentication method */
parse_client_timeout /* client defined timeout */
};
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((int)(unsigned char)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;
if (num_fields(ndx) < MIN_SPA_FIELDS)
return(FKO_ERROR_INVALID_DATA_DECODE_LT_MIN_FIELDS);
ndx += last_field(ndx);
t_size = strnlen(ndx, SHA512_B64_LEN+1);
/* Validate digest length
*/
res = is_valid_digest_len(t_size, ctx);
if(res != FKO_SUCCESS)
return res;
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);
/* Chop the digest off 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 = calloc(1, FKO_ENCODE_TMP_BUF_SIZE);
if(tbuf == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Can now verify the digest.
*/
res = verify_digest(tbuf, t_size, ctx);
if(res != FKO_SUCCESS)
{
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;
for (i=0; i < FIELD_PARSERS; i++)
{
res = (*field_parser[i])(tbuf, &ndx, &t_size, ctx);
if(res != FKO_SUCCESS)
{
free(tbuf);
return res;
}
}
/* Done with the tmp buffer.
*/
free(tbuf);
/* Call the context initialized.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
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);
}
/* Decrypt the encoded SPA data.
*/
int
fko_decode_spa_data(fko_ctx_t ctx)
{
char *tbuf, *ndx;
int edata_size, t_size;
/* Check for required data.
*/
if(ctx->encoded_msg == NULL
|| strlen(ctx->encoded_msg) < MIN_SPA_ENCODED_MSG_SIZE)
return(FKO_ERROR_INVALID_DATA);
edata_size = strlen(ctx->encoded_msg);
/* Move the Digest to its place in the context.
*/
ndx = strrchr(ctx->encoded_msg, ':'); /* Find the last : in the data */
if(ndx == NULL)
return(FKO_ERROR_INVALID_DATA);
ndx++;
t_size = strlen(ndx);
switch(t_size)
{
case MD5_B64_LENGTH:
ctx->digest_type = FKO_DIGEST_MD5;
break;
case SHA1_B64_LENGTH:
ctx->digest_type = FKO_DIGEST_SHA1;
break;
case SHA256_B64_LENGTH:
ctx->digest_type = FKO_DIGEST_SHA256;
break;
case SHA384_B64_LENGTH:
ctx->digest_type = FKO_DIGEST_SHA384;
break;
case SHA512_B64_LENGTH:
ctx->digest_type = FKO_DIGEST_SHA512;
break;
default: /* Invalid or unsupported digest */
return(FKO_ERROR_INVALID_DIGEST_TYPE);
}
/* 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);
/* 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, strlen(ctx->encoded_msg));
break;
case FKO_DIGEST_SHA1:
sha1_base64(tbuf, (unsigned char*)ctx->encoded_msg, strlen(ctx->encoded_msg));
break;
case FKO_DIGEST_SHA256:
sha256_base64(tbuf, (unsigned char*)ctx->encoded_msg, strlen(ctx->encoded_msg));
break;
case FKO_DIGEST_SHA384:
sha384_base64(tbuf, (unsigned char*)ctx->encoded_msg, strlen(ctx->encoded_msg));
break;
case FKO_DIGEST_SHA512:
sha512_base64(tbuf, (unsigned char*)ctx->encoded_msg, strlen(ctx->encoded_msg));
break;
}
/* We give up here if the computed digest does not match the
* digest in the message data.
*/
if(strcmp(ctx->digest, tbuf))
{
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);
}
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);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->username = malloc(t_size+1); /* Yes, more than we need */
if(ctx->username == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
b64_decode(tbuf, (unsigned char*)ctx->username, t_size);
/* Extract the timestamp value.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->timestamp = (unsigned int)atoi(tbuf);
/* Extract the version string.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA);
}
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);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->message_type = (unsigned int)atoi(tbuf);
/* Extract the SPA message string.
*/
ndx += t_size + 1;
if((t_size = strcspn(ndx, ":")) < 1)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->message = malloc(t_size+1); /* Yes, more than we need */
if(ctx->message == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
b64_decode(tbuf, (unsigned char*)ctx->message, t_size);
/* 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);
}
strlcpy(tbuf, ndx, t_size+1);
ctx->nat_access = malloc(t_size+1); /* Yes, more than we need */
if(ctx->nat_access == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
b64_decode(tbuf, (unsigned char*)ctx->nat_access, t_size);
}
/* Now look for a server_auth string.
*/
ndx += t_size + 1;
if((t_size = strlen(ndx)) > 0)
{
/* 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);
ctx->server_auth = malloc(t_size+1); /* Yes, more than we need */
if(ctx->server_auth == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
b64_decode(tbuf, (unsigned char*)ctx->server_auth, t_size);
/* 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, ":");
/* Looks like we have both, so assume this is the
*/
strlcpy(tbuf, ndx, t_size+1);
ctx->server_auth = malloc(t_size+1); /* Yes, more than we need */
if(ctx->server_auth == NULL)
{
free(tbuf);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
b64_decode(tbuf, (unsigned char*)ctx->server_auth, t_size);
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);
}
/* Should be a number only.
*/
if(strspn(ndx, "0123456789") != t_size)
{
free(tbuf);
return(FKO_ERROR_INVALID_DATA);
}
ctx->client_timeout = (unsigned int)atoi(ndx);
}
}
/* Done with the tmp buffer.
*/
free(tbuf);
/* Call the context initialized.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
return(FKO_SUCCESS);
}
/* Initialize an fko context.
*/
int
fko_new(fko_ctx_t *r_ctx)
{
fko_ctx_t ctx;
int res;
char *ver;
ctx = calloc(1, sizeof *ctx);
if(ctx == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Set default values and state.
*
* Note: We have to explicitly set the ctx->state to initialized
* just before making an fko_xxx function call, then set it
* back to zero just afer. During initialization, we need
* to make these functions think they are operating on an
* initialized context, or else they would fail.
*/
/* Set the version string.
*/
ctx->initval = FKO_CTX_INITIALIZED;
ver = strdup(FKO_PROTOCOL_VERSION);
ctx->initval = 0;
if(ver == NULL)
{
free(ctx);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
ctx->version = ver;
/* Rand value.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_rand_value(ctx, NULL);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
/* Username.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_username(ctx, NULL);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
/* Timestamp.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_timestamp(ctx, 0);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
/* Default Digest Type.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_spa_digest_type(ctx, FKO_DEFAULT_DIGEST);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
/* Default Message Type.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_spa_message_type(ctx, FKO_DEFAULT_MSG_TYPE);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
/* Default Encryption Type.
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_spa_encryption_type(ctx, FKO_DEFAULT_ENCRYPTION);
ctx->initval = 0;
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
return res;
}
#if HAVE_LIBGPGME
/* Set gpg signature verify on.
*/
ctx->verify_gpg_sigs = 1;
#endif /* HAVE_LIBGPGME */
/* Now we mean it.
*/
ctx->initval = FKO_CTX_INITIALIZED;
FKO_SET_CTX_INITIALIZED(ctx);
*r_ctx = ctx;
return(FKO_SUCCESS);
}
/* Initialize an fko context.
*/
int
fko_new(fko_ctx_t *r_ctx)
{
fko_ctx_t ctx = NULL;
int res;
char *ver;
#if HAVE_LIBFIU
fiu_return_on("fko_new_calloc", FKO_ERROR_MEMORY_ALLOCATION);
#endif
ctx = calloc(1, sizeof *ctx);
if(ctx == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
/* Set default values and state.
*
* Note: We initialize the context early so that the fko_set_xxx
* functions can operate properly. If there are any problems during
* initialization, then fko_destroy() is called which will clean up
* the context.
*/
ctx->initval = FKO_CTX_INITIALIZED;
/* Set the version string.
*/
ver = strdup(FKO_PROTOCOL_VERSION);
if(ver == NULL)
{
fko_destroy(ctx);
ctx = NULL;
return(FKO_ERROR_MEMORY_ALLOCATION);
}
ctx->version = ver;
/* Rand value.
*/
res = fko_set_rand_value(ctx, NULL);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Username.
*/
res = fko_set_username(ctx, NULL);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Timestamp.
*/
res = fko_set_timestamp(ctx, 0);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Default Digest Type.
*/
res = fko_set_spa_digest_type(ctx, FKO_DEFAULT_DIGEST);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Default Message Type.
*/
res = fko_set_spa_message_type(ctx, FKO_DEFAULT_MSG_TYPE);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Default Encryption Type.
*/
res = fko_set_spa_encryption_type(ctx, FKO_DEFAULT_ENCRYPTION);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Default is Rijndael in CBC mode
*/
res = fko_set_spa_encryption_mode(ctx, FKO_DEFAULT_ENC_MODE);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
#if HAVE_LIBGPGME
/* Set gpg signature verify on.
*/
ctx->verify_gpg_sigs = 1;
#endif /* HAVE_LIBGPGME */
FKO_SET_CTX_INITIALIZED(ctx);
*r_ctx = ctx;
return(FKO_SUCCESS);
}
/* Initialize an fko context with external (encrypted/encoded) data.
* This is used to create a context with the purpose of decoding
* and parsing the provided data into the context data.
*/
int
fko_new_with_data(fko_ctx_t *r_ctx, const char * const enc_msg,
const char * const dec_key, const int dec_key_len,
int encryption_mode, const char * const hmac_key,
const int hmac_key_len, const int hmac_type)
{
fko_ctx_t ctx = NULL;
int res = FKO_SUCCESS; /* Are we optimistic or what? */
int enc_msg_len;
#if HAVE_LIBFIU
fiu_return_on("fko_new_with_data_msg",
FKO_ERROR_INVALID_DATA_FUNCS_NEW_ENCMSG_MISSING);
#endif
if(enc_msg == NULL)
return(FKO_ERROR_INVALID_DATA_FUNCS_NEW_ENCMSG_MISSING);
#if HAVE_LIBFIU
fiu_return_on("fko_new_with_data_keylen",
FKO_ERROR_INVALID_KEY_LEN);
#endif
if(dec_key_len < 0 || hmac_key_len < 0)
return(FKO_ERROR_INVALID_KEY_LEN);
ctx = calloc(1, sizeof *ctx);
if(ctx == NULL)
return(FKO_ERROR_MEMORY_ALLOCATION);
enc_msg_len = strnlen(enc_msg, MAX_SPA_ENCODED_MSG_SIZE);
if(! is_valid_encoded_msg_len(enc_msg_len))
{
free(ctx);
return(FKO_ERROR_INVALID_DATA_FUNCS_NEW_MSGLEN_VALIDFAIL);
}
/* First, add the data to the context.
*/
ctx->encrypted_msg = strdup(enc_msg);
ctx->encrypted_msg_len = enc_msg_len;
if(ctx->encrypted_msg == NULL)
{
free(ctx);
return(FKO_ERROR_MEMORY_ALLOCATION);
}
/* Default Encryption Mode (Rijndael in CBC mode)
*/
ctx->initval = FKO_CTX_INITIALIZED;
res = fko_set_spa_encryption_mode(ctx, encryption_mode);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* HMAC digest type
*/
res = fko_set_spa_hmac_type(ctx, hmac_type);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Check HMAC if the access stanza had an HMAC key
*/
if(hmac_key_len > 0 && hmac_key != NULL)
res = fko_verify_hmac(ctx, hmac_key, hmac_key_len);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
return res;
}
/* Consider it initialized here.
*/
FKO_SET_CTX_INITIALIZED(ctx);
/* If a decryption key is provided, go ahead and decrypt and decode.
*/
if(dec_key != NULL)
{
res = fko_decrypt_spa_data(ctx, dec_key, dec_key_len);
if(res != FKO_SUCCESS)
{
fko_destroy(ctx);
ctx = NULL;
*r_ctx = NULL; /* Make sure the caller ctx is null just in case */
return(res);
}
}
#if HAVE_LIBGPGME
/* Set gpg signature verify on.
*/
ctx->verify_gpg_sigs = 1;
#endif /* HAVE_LIBGPGME */
*r_ctx = ctx;
return(res);
}
