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-rw-r--r--aclk/aclk_otp.c404
1 files changed, 189 insertions, 215 deletions
diff --git a/aclk/aclk_otp.c b/aclk/aclk_otp.c
index 658e04f9..c99c6563 100644
--- a/aclk/aclk_otp.c
+++ b/aclk/aclk_otp.c
@@ -9,164 +9,6 @@
#include "mqtt_websockets/c-rbuf/include/ringbuffer.h"
-struct dictionary_singleton {
- char *key;
- char *result;
-};
-
-static int json_extract_singleton(JSON_ENTRY *e)
-{
- struct dictionary_singleton *data = e->callback_data;
-
- switch (e->type) {
- case JSON_OBJECT:
- case JSON_ARRAY:
- break;
- case JSON_STRING:
- if (!strcmp(e->name, data->key)) {
- data->result = strdupz(e->data.string);
- break;
- }
- break;
- case JSON_NUMBER:
- case JSON_BOOLEAN:
- case JSON_NULL:
- break;
- }
- return 0;
-}
-
-// Base-64 decoder.
-// Note: This is non-validating, invalid input will be decoded without an error.
-// Challenges are packed into json strings so we don't skip newlines.
-// Size errors (i.e. invalid input size or insufficient output space) are caught.
-static size_t base64_decode(unsigned char *input, size_t input_size, unsigned char *output, size_t output_size)
-{
- static char lookup[256];
- static int first_time=1;
- if (first_time)
- {
- first_time = 0;
- for(int i=0; i<256; i++)
- lookup[i] = -1;
- for(int i='A'; i<='Z'; i++)
- lookup[i] = i-'A';
- for(int i='a'; i<='z'; i++)
- lookup[i] = i-'a' + 26;
- for(int i='0'; i<='9'; i++)
- lookup[i] = i-'0' + 52;
- lookup['+'] = 62;
- lookup['/'] = 63;
- }
- if ((input_size & 3) != 0)
- {
- error("Can't decode base-64 input length %zu", input_size);
- return 0;
- }
- size_t unpadded_size = (input_size/4) * 3;
- if ( unpadded_size > output_size )
- {
- error("Output buffer size %zu is too small to decode %zu into", output_size, input_size);
- return 0;
- }
- // Don't check padding within full quantums
- for (size_t i = 0 ; i < input_size-4 ; i+=4 )
- {
- uint32_t value = (lookup[input[0]] << 18) + (lookup[input[1]] << 12) + (lookup[input[2]] << 6) + lookup[input[3]];
- output[0] = value >> 16;
- output[1] = value >> 8;
- output[2] = value;
- //error("Decoded %c %c %c %c -> %02x %02x %02x", input[0], input[1], input[2], input[3], output[0], output[1], output[2]);
- output += 3;
- input += 4;
- }
- // Handle padding only in last quantum
- if (input[2] == '=') {
- uint32_t value = (lookup[input[0]] << 6) + lookup[input[1]];
- output[0] = value >> 4;
- //error("Decoded %c %c %c %c -> %02x", input[0], input[1], input[2], input[3], output[0]);
- return unpadded_size-2;
- }
- else if (input[3] == '=') {
- uint32_t value = (lookup[input[0]] << 12) + (lookup[input[1]] << 6) + lookup[input[2]];
- output[0] = value >> 10;
- output[1] = value >> 2;
- //error("Decoded %c %c %c %c -> %02x %02x", input[0], input[1], input[2], input[3], output[0], output[1]);
- return unpadded_size-1;
- }
- else
- {
- uint32_t value = (input[0] << 18) + (input[1] << 12) + (input[2]<<6) + input[3];
- output[0] = value >> 16;
- output[1] = value >> 8;
- output[2] = value;
- //error("Decoded %c %c %c %c -> %02x %02x %02x", input[0], input[1], input[2], input[3], output[0], output[1], output[2]);
- return unpadded_size;
- }
-}
-
-static size_t base64_encode(unsigned char *input, size_t input_size, char *output, size_t output_size)
-{
- uint32_t value;
- static char lookup[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "0123456789+/";
- if ((input_size/3+1)*4 >= output_size)
- {
- error("Output buffer for encoding size=%zu is not large enough for %zu-bytes input", output_size, input_size);
- return 0;
- }
- size_t count = 0;
- while (input_size>3)
- {
- value = ((input[0] << 16) + (input[1] << 8) + input[2]) & 0xffffff;
- output[0] = lookup[value >> 18];
- output[1] = lookup[(value >> 12) & 0x3f];
- output[2] = lookup[(value >> 6) & 0x3f];
- output[3] = lookup[value & 0x3f];
- //error("Base-64 encode (%04x) -> %c %c %c %c\n", value, output[0], output[1], output[2], output[3]);
- output += 4;
- input += 3;
- input_size -= 3;
- count += 4;
- }
- switch (input_size)
- {
- case 2:
- value = (input[0] << 10) + (input[1] << 2);
- output[0] = lookup[(value >> 12) & 0x3f];
- output[1] = lookup[(value >> 6) & 0x3f];
- output[2] = lookup[value & 0x3f];
- output[3] = '=';
- //error("Base-64 encode (%06x) -> %c %c %c %c\n", (value>>2)&0xffff, output[0], output[1], output[2], output[3]);
- count += 4;
- break;
- case 1:
- value = input[0] << 4;
- output[0] = lookup[(value >> 6) & 0x3f];
- output[1] = lookup[value & 0x3f];
- output[2] = '=';
- output[3] = '=';
- //error("Base-64 encode (%06x) -> %c %c %c %c\n", value, output[0], output[1], output[2], output[3]);
- count += 4;
- break;
- case 0:
- break;
- }
- return count;
-}
-
-static int private_decrypt(RSA *p_key, unsigned char * enc_data, int data_len, unsigned char *decrypted)
-{
- int result = RSA_private_decrypt( data_len, enc_data, decrypted, p_key, RSA_PKCS1_OAEP_PADDING);
- if (result == -1) {
- char err[512];
- ERR_error_string_n(ERR_get_error(), err, sizeof(err));
- error("Decryption of the challenge failed: %s", err);
- }
- return result;
-}
-
static int aclk_https_request(https_req_t *request, https_req_response_t *response) {
int rc;
// wrapper for ACLK only which loads ACLK specific proxy settings
@@ -426,112 +268,242 @@ exit:
}
#endif
+#if defined(OPENSSL_VERSION_NUMBER) && OPENSSL_VERSION_NUMBER < OPENSSL_VERSION_110
+static EVP_ENCODE_CTX *EVP_ENCODE_CTX_new(void)
+{
+ EVP_ENCODE_CTX *ctx = OPENSSL_malloc(sizeof(*ctx));
+
+ if (ctx != NULL) {
+ memset(ctx, 0, sizeof(*ctx));
+ }
+ return ctx;
+}
+static void EVP_ENCODE_CTX_free(EVP_ENCODE_CTX *ctx)
+{
+ OPENSSL_free(ctx);
+ return;
+}
+#endif
+
+#define CHALLENGE_LEN 256
+#define CHALLENGE_LEN_BASE64 344
+inline static int base64_decode_helper(unsigned char *out, int *outl, const unsigned char *in, int in_len)
+{
+ unsigned char remaining_data[CHALLENGE_LEN];
+ EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
+ EVP_DecodeInit(ctx);
+ EVP_DecodeUpdate(ctx, out, outl, in, in_len);
+ int remainder = 0;
+ EVP_DecodeFinal(ctx, remaining_data, &remainder);
+ EVP_ENCODE_CTX_free(ctx);
+ if (remainder) {
+ error("Unexpected data at EVP_DecodeFinal");
+ return 1;
+ }
+ return 0;
+}
+
+inline static int base64_encode_helper(unsigned char *out, int *outl, const unsigned char *in, int in_len)
+{
+ int len;
+ unsigned char *str = out;
+ EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
+ EVP_EncodeInit(ctx);
+ EVP_EncodeUpdate(ctx, str, outl, in, in_len);
+ str += *outl;
+ EVP_EncodeFinal(ctx, str, &len);
+ *outl += len;
+ // if we ever expect longer output than what OpenSSL would pack into single line
+ // we would have to skip the endlines, until then we can just cut the string short
+ str = (unsigned char*)strchr((char*)out, '\n');
+ if (str)
+ *str = 0;
+ EVP_ENCODE_CTX_free(ctx);
+ return 0;
+}
+
#define OTP_URL_PREFIX "/api/v1/auth/node/"
-int aclk_get_mqtt_otp(RSA *p_key, char **mqtt_id, char **mqtt_usr, char **mqtt_pass, url_t *target) {
- // TODO this fnc will be rewritten and simplified in following PRs
- // still carries lot of baggage from ACLK Legacy
+int aclk_get_otp_challenge(url_t *target, const char *agent_id, unsigned char **challenge, int *challenge_bytes)
+{
int rc = 1;
- BUFFER *url = buffer_create(strlen(OTP_URL_PREFIX) + UUID_STR_LEN + 20);
-
https_req_t req = HTTPS_REQ_T_INITIALIZER;
https_req_response_t resp = HTTPS_REQ_RESPONSE_T_INITIALIZER;
- char *agent_id = is_agent_claimed();
- if (agent_id == NULL)
- {
- error("Agent was not claimed - cannot perform challenge/response");
- goto cleanup;
- }
+ BUFFER *url = buffer_create(strlen(OTP_URL_PREFIX) + UUID_STR_LEN + 20);
- // GET Challenge
req.host = target->host;
req.port = target->port;
buffer_sprintf(url, "%s/node/%s/challenge", target->path, agent_id);
- req.url = url->buffer;
+ req.url = (char *)buffer_tostring(url);
if (aclk_https_request(&req, &resp)) {
error ("ACLK_OTP Challenge failed");
- goto cleanup;
+ buffer_free(url);
+ return 1;
}
if (resp.http_code != 200) {
error ("ACLK_OTP Challenge HTTP code not 200 OK (got %d)", resp.http_code);
+ buffer_free(url);
if (resp.payload_size)
aclk_parse_otp_error(resp.payload);
goto cleanup_resp;
}
- info ("ACLK_OTP Got Challenge from Cloud");
+ buffer_free(url);
- struct dictionary_singleton challenge = { .key = "challenge", .result = NULL };
+ info ("ACLK_OTP Got Challenge from Cloud");
- if (json_parse(resp.payload, &challenge, json_extract_singleton) != JSON_OK)
- {
- freez(challenge.result);
- error("Could not parse the the challenge");
+ json_object *json = json_tokener_parse(resp.payload);
+ if (!json) {
+ error ("Couldn't parse HTTP GET challenge payload");
goto cleanup_resp;
}
- if (challenge.result == NULL) {
- error("Could not retrieve challenge JSON key from challenge response");
- goto cleanup_resp;
+ json_object *challenge_json;
+ if (!json_object_object_get_ex(json, "challenge", &challenge_json)) {
+ error ("No key named \"challenge\" in the returned JSON");
+ goto cleanup_json;
+ }
+ if (!json_object_is_type(challenge_json, json_type_string)) {
+ error ("\"challenge\" is not a string JSON type");
+ goto cleanup_json;
+ }
+ const char *challenge_base64;
+ if (!(challenge_base64 = json_object_get_string(challenge_json))) {
+ error("Failed to extract challenge from JSON object");
+ goto cleanup_json;
+ }
+ if (strlen(challenge_base64) != CHALLENGE_LEN_BASE64) {
+ error("Received Challenge has unexpected length of %zu (expected %d)", strlen(challenge_base64), CHALLENGE_LEN_BASE64);
+ goto cleanup_json;
}
- // Decrypt the Challenge and Calculate Response
- size_t challenge_len = strlen(challenge.result);
- unsigned char decoded[512];
- size_t decoded_len = base64_decode((unsigned char*)challenge.result, challenge_len, decoded, sizeof(decoded));
- freez(challenge.result);
-
- unsigned char plaintext[4096]={};
- int decrypted_length = private_decrypt(p_key, decoded, decoded_len, plaintext);
- char encoded[512];
- size_t encoded_len = base64_encode(plaintext, decrypted_length, encoded, sizeof(encoded));
- encoded[encoded_len] = 0;
- debug(D_ACLK, "Encoded len=%zu Decryption len=%d: '%s'", encoded_len, decrypted_length, encoded);
-
- char response_json[4096]={};
- sprintf(response_json, "{\"response\":\"%s\"}", encoded);
- debug(D_ACLK, "Password phase: %s",response_json);
+ *challenge = mallocz((CHALLENGE_LEN_BASE64 / 4) * 3);
+ base64_decode_helper(*challenge, challenge_bytes, (const unsigned char*)challenge_base64, strlen(challenge_base64));
+ if (*challenge_bytes != CHALLENGE_LEN) {
+ error("Unexpected challenge length of %d instead of %d", *challenge_bytes, CHALLENGE_LEN);
+ freez(challenge);
+ *challenge = NULL;
+ goto cleanup_json;
+ }
+ rc = 0;
+cleanup_json:
+ json_object_put(json);
+cleanup_resp:
https_req_response_free(&resp);
- https_req_response_init(&resp);
+ return rc;
+}
- // POST password
+int aclk_send_otp_response(const char *agent_id, const unsigned char *response, int response_bytes, url_t *target, struct auth_data *mqtt_auth)
+{
+ int len;
+ int rc = 1;
+ https_req_t req = HTTPS_REQ_T_INITIALIZER;
+ https_req_response_t resp = HTTPS_REQ_RESPONSE_T_INITIALIZER;
+
+ req.host = target->host;
+ req.port = target->port;
req.request_type = HTTP_REQ_POST;
- buffer_flush(url);
+
+ unsigned char base64[CHALLENGE_LEN_BASE64 + 1];
+ memset(base64, 0, CHALLENGE_LEN_BASE64 + 1);
+
+ base64_encode_helper(base64, &len, response, response_bytes);
+
+ BUFFER *url = buffer_create(strlen(OTP_URL_PREFIX) + UUID_STR_LEN + 20);
+ BUFFER *resp_json = buffer_create(strlen(OTP_URL_PREFIX) + UUID_STR_LEN + 20);
+
buffer_sprintf(url, "%s/node/%s/password", target->path, agent_id);
- req.url = url->buffer;
- req.payload = response_json;
- req.payload_size = strlen(response_json);
+ buffer_sprintf(resp_json, "{\"response\":\"%s\"}", base64);
+
+ req.url = (char *)buffer_tostring(url);
+ req.payload = (char *)buffer_tostring(resp_json);
+ req.payload_size = strlen(req.payload);
if (aclk_https_request(&req, &resp)) {
error ("ACLK_OTP Password error trying to post result to password");
- goto cleanup;
+ goto cleanup_buffers;
}
if (resp.http_code != 201) {
error ("ACLK_OTP Password HTTP code not 201 Created (got %d)", resp.http_code);
if (resp.payload_size)
aclk_parse_otp_error(resp.payload);
- goto cleanup_resp;
+ goto cleanup_response;
}
info ("ACLK_OTP Got Password from Cloud");
- struct auth_data data = { .client_id = NULL, .passwd = NULL, .username = NULL };
-
- if (parse_passwd_response(resp.payload, &data)){
+ if (parse_passwd_response(resp.payload, mqtt_auth)){
error("Error parsing response of password endpoint");
- goto cleanup_resp;
+ goto cleanup_response;
+ }
+
+ rc = 0;
+
+cleanup_response:
+ https_req_response_free(&resp);
+cleanup_buffers:
+ buffer_free(resp_json);
+ buffer_free(url);
+ return rc;
+}
+
+static int private_decrypt(RSA *p_key, unsigned char * enc_data, int data_len, unsigned char **decrypted)
+{
+ *decrypted = mallocz(RSA_size(p_key));
+ int result = RSA_private_decrypt(data_len, enc_data, *decrypted, p_key, RSA_PKCS1_OAEP_PADDING);
+ if (result == -1) {
+ char err[512];
+ ERR_error_string_n(ERR_get_error(), err, sizeof(err));
+ error("Decryption of the challenge failed: %s", err);
+ }
+ return result;
+}
+
+int aclk_get_mqtt_otp(RSA *p_key, char **mqtt_id, char **mqtt_usr, char **mqtt_pass, url_t *target)
+{
+ unsigned char *challenge;
+ int challenge_bytes;
+
+ char *agent_id = is_agent_claimed();
+ if (agent_id == NULL) {
+ error("Agent was not claimed - cannot perform challenge/response");
+ return 1;
+ }
+
+ // Get Challenge
+ if (aclk_get_otp_challenge(target, agent_id, &challenge, &challenge_bytes)) {
+ error("Error getting challenge");
+ freez(agent_id);
+ return 1;
+ }
+
+ // Decrypt Challenge / Get response
+ unsigned char *response_plaintext;
+ int response_plaintext_bytes = private_decrypt(p_key, challenge, challenge_bytes, &response_plaintext);
+ if (response_plaintext_bytes < 0) {
+ error ("Couldn't decrypt the challenge received");
+ freez(response_plaintext);
+ freez(challenge);
+ freez(agent_id);
+ return 1;
+ }
+ freez(challenge);
+
+ // Encode and Send Challenge
+ struct auth_data data = { .client_id = NULL, .passwd = NULL, .username = NULL };
+ if (aclk_send_otp_response(agent_id, response_plaintext, response_plaintext_bytes, target, &data)) {
+ error("Error getting response");
+ freez(response_plaintext);
+ freez(agent_id);
+ return 1;
}
*mqtt_pass = data.passwd;
*mqtt_usr = data.username;
*mqtt_id = data.client_id;
- rc = 0;
-cleanup_resp:
- https_req_response_free(&resp);
-cleanup:
+ freez(response_plaintext);
freez(agent_id);
- buffer_free(url);
- return rc;
+ return 0;
}
#define JSON_KEY_ENC "encoding"
@@ -860,6 +832,8 @@ int aclk_get_env(aclk_env_t *env, const char* aclk_hostname, int aclk_port) {
}
if (resp.http_code != 200) {
error("The HTTP code not 200 OK (Got %d)", resp.http_code);
+ if (resp.payload_size)
+ aclk_parse_otp_error(resp.payload);
https_req_response_free(&resp);
buffer_free(buf);
return 1;
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-03 07:21:41 +0000