diff options
Diffstat (limited to 'src/plugins/irc/irc-sasl.c')
| -rw-r--r-- | src/plugins/irc/irc-sasl.c | 260 |
1 files changed, 205 insertions, 55 deletions
diff --git a/src/plugins/irc/irc-sasl.c b/src/plugins/irc/irc-sasl.c index db3ab9f7d..a410ad826 100644 --- a/src/plugins/irc/irc-sasl.c +++ b/src/plugins/irc/irc-sasl.c @@ -31,7 +31,7 @@ char *irc_sasl_mechanism_string[IRC_NUM_SASL_MECHANISMS] = -{ "plain", "dh-blowfish", "external" }; +{ "plain", "dh-blowfish", "dh-aes", "external" }; /* @@ -68,39 +68,28 @@ irc_sasl_mechanism_plain (const char *sasl_username, const char *sasl_password) } /* - * Builds answer for SASL authentication, using mechanism "DH-BLOWFISH". + * Reads key sent by server (Diffie-Hellman key exchange). * - * Argument data_base64 is a concatenation of 3 strings, each string is composed - * of 2 bytes (length of string), followed by content of string: - * 1. a prime number - * 2. a generator number - * 3. server-generated public key - * - * Note: result must be freed after use. + * Returns: + * 1: OK + * 0: error */ -char * -irc_sasl_mechanism_dh_blowfish (const char *data_base64, - const char *sasl_username, - const char *sasl_password) +int +irc_sasl_dh (const char *data_base64, + unsigned char **public_bin, unsigned char **secret_bin, + int *length_key) { - char *data, *answer, *ptr_answer, *answer_base64; - unsigned char *ptr_data, *secret_bin, *public_bin; - unsigned char *password_clear, *password_crypted; - int length_data, size, num_bits_prime_number, length_key; - int length_username, length_password, length_answer; + char *data; + unsigned char *ptr_data; + int length_data, size, num_bits_prime_number, rc; size_t num_written; gcry_mpi_t data_prime_number, data_generator_number, data_server_pub_key; gcry_mpi_t pub_key, priv_key, secret_mpi; - gcry_cipher_hd_t gcrypt_handle; + + rc = 0; data = NULL; - secret_bin = NULL; - public_bin = NULL; - password_clear = NULL; - password_crypted = NULL; - answer = NULL; - answer_base64 = NULL; data_prime_number = NULL; data_generator_number = NULL; data_server_pub_key = NULL; @@ -118,7 +107,7 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, ptr_data += 2; length_data -= 2; if (size > length_data) - goto end; + goto dhend; data_prime_number = gcry_mpi_new (size * 8); gcry_mpi_scan (&data_prime_number, GCRYMPI_FMT_USG, ptr_data, size, NULL); num_bits_prime_number = gcry_mpi_get_nbits (data_prime_number); @@ -130,7 +119,7 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, ptr_data += 2; length_data -= 2; if (size > length_data) - goto end; + goto dhend; data_generator_number = gcry_mpi_new (size * 8); gcry_mpi_scan (&data_generator_number, GCRYMPI_FMT_USG, ptr_data, size, NULL); ptr_data += size; @@ -141,7 +130,7 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, ptr_data += 2; length_data -= 2; if (size > length_data) - goto end; + goto dhend; data_server_pub_key = gcry_mpi_new (size * 8); gcry_mpi_scan (&data_server_pub_key, GCRYMPI_FMT_USG, ptr_data, size, NULL); @@ -153,18 +142,70 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, gcry_mpi_powm (pub_key, data_generator_number, priv_key, data_prime_number); /* compute secret_bin */ - length_key = num_bits_prime_number / 8; - secret_bin = malloc (length_key); + *length_key = num_bits_prime_number / 8; + *secret_bin = malloc (*length_key); secret_mpi = gcry_mpi_new (num_bits_prime_number); /* secret_mpi = (y ^ priv_key) % p */ gcry_mpi_powm (secret_mpi, data_server_pub_key, priv_key, data_prime_number); - gcry_mpi_print (GCRYMPI_FMT_USG, secret_bin, length_key, + gcry_mpi_print (GCRYMPI_FMT_USG, *secret_bin, *length_key, &num_written, secret_mpi); /* create public_bin */ - public_bin = malloc (length_key); - gcry_mpi_print (GCRYMPI_FMT_USG, public_bin, length_key, + *public_bin = malloc (*length_key); + gcry_mpi_print (GCRYMPI_FMT_USG, *public_bin, *length_key, &num_written, pub_key); + rc = 1; + +dhend: + if (data) + free (data); + if (data_prime_number) + gcry_mpi_release (data_prime_number); + if (data_generator_number) + gcry_mpi_release (data_generator_number); + if (data_server_pub_key) + gcry_mpi_release (data_server_pub_key); + if (pub_key) + gcry_mpi_release (pub_key); + if (priv_key) + gcry_mpi_release (priv_key); + if (secret_mpi) + gcry_mpi_release (secret_mpi); + + return rc; +} + +/* + * Builds answer for SASL authentication, using mechanism "DH-BLOWFISH". + * + * Argument data_base64 is a concatenation of 3 strings, each string is composed + * of 2 bytes (length of string), followed by content of string: + * 1. a prime number + * 2. a generator number + * 3. server-generated public key + * + * Note: result must be freed after use. + */ +char * +irc_sasl_mechanism_dh_blowfish (const char *data_base64, + const char *sasl_username, + const char *sasl_password) +{ + char *answer, *ptr_answer, *answer_base64; + unsigned char *password_clear, *password_crypted; + int length_key, length_username, length_password, length_answer; + unsigned char *public_bin, *secret_bin; + gcry_cipher_hd_t gcrypt_handle; + + password_clear = NULL; + password_crypted = NULL; + answer = NULL; + answer_base64 = NULL; + secret_bin = NULL; + public_bin = NULL; + + if (!irc_sasl_dh (data_base64, &public_bin, &secret_bin, &length_key)) + goto bfend; /* create password buffers (clear and crypted) */ length_password = strlen (sasl_password) + @@ -178,13 +219,15 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, /* crypt password using blowfish */ if (gcry_cipher_open (&gcrypt_handle, GCRY_CIPHER_BLOWFISH, GCRY_CIPHER_MODE_ECB, 0) != 0) - goto end; + goto bfend; if (gcry_cipher_setkey (gcrypt_handle, secret_bin, length_key) != 0) - goto end; + goto bfend; if (gcry_cipher_encrypt (gcrypt_handle, password_crypted, length_password, password_clear, length_password) != 0) - goto end; + goto bfend; + + gcry_cipher_close (gcrypt_handle); /* * build answer for server, it is concatenation of: @@ -193,16 +236,16 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, * 3. sasl_username ('length_username'+1 bytes) * 4. encrypted password ('length_password' bytes) */ - length_username = strlen (sasl_username); - length_answer = 2 + length_key + length_username + 1 + length_password; + length_username = strlen (sasl_username) + 1; + length_answer = 2 + length_key + length_username + length_password; answer = malloc (length_answer); ptr_answer = answer; *((unsigned int *)ptr_answer) = htons(length_key); ptr_answer += 2; memcpy (ptr_answer, public_bin, length_key); ptr_answer += length_key; - memcpy (ptr_answer, sasl_username, length_username + 1); - ptr_answer += length_username + 1; + memcpy (ptr_answer, sasl_username, length_username); + ptr_answer += length_username; memcpy (ptr_answer, password_crypted, length_password); /* encode answer to base64 */ @@ -210,9 +253,7 @@ irc_sasl_mechanism_dh_blowfish (const char *data_base64, if (answer_base64) weechat_string_encode_base64 (answer, length_answer, answer_base64); -end: - if (data) - free (data); +bfend: if (secret_bin) free (secret_bin); if (public_bin) @@ -223,18 +264,127 @@ end: free (password_crypted); if (answer) free (answer); - if (data_prime_number) - gcry_mpi_release (data_prime_number); - if (data_generator_number) - gcry_mpi_release (data_generator_number); - if (data_server_pub_key) - gcry_mpi_release (data_server_pub_key); - if (pub_key) - gcry_mpi_release (pub_key); - if (priv_key) - gcry_mpi_release (priv_key); - if (secret_mpi) - gcry_mpi_release (secret_mpi); + + return answer_base64; +} + +/* + * Builds answer for SASL authentication, using mechanism "DH-AES". + * + * Argument data_base64 is a concatenation of 3 strings, each string is composed + * of 2 bytes (length of string), followed by content of string: + * 1. a prime number + * 2. a generator number + * 3. server-generated public key + * + * Note: result must be freed after use. + */ +char * +irc_sasl_mechanism_dh_aes (const char *data_base64, + const char *sasl_username, + const char *sasl_password) +{ + char *answer, *ptr_answer, *answer_base64; + unsigned char *ptr_userpass, *userpass_clear, *userpass_crypted; + int length_key, length_answer; + int length_username, length_password, length_userpass; + unsigned char *public_bin, *secret_bin; + char iv[16]; + int cipher_algo; + gcry_cipher_hd_t gcrypt_handle; + + userpass_clear = NULL; + userpass_crypted = NULL; + answer = NULL; + answer_base64 = NULL; + secret_bin = NULL; + public_bin = NULL; + + if (irc_sasl_dh(data_base64, &public_bin, &secret_bin, &length_key) == 0) + goto aesend; + + /* Select cipher algorithm: key length * 8 = cipher bit size */ + switch (length_key) + { + case 32: + cipher_algo = GCRY_CIPHER_AES256; + break; + case 24: + cipher_algo = GCRY_CIPHER_AES192; + break; + case 16: + cipher_algo = GCRY_CIPHER_AES128; + break; + default: + /* Invalid bit length */ + goto aesend; + } + + /* Generate the IV */ + gcry_randomize (iv, sizeof (iv), GCRY_STRONG_RANDOM); + + /* create user/pass buffers (clear and crypted) */ + length_username = strlen (sasl_username) + 1; + length_password = strlen (sasl_password) + 1; + length_userpass = length_username + length_password + + ((16 - ((length_username + length_password) % 16)) % 16); + ptr_userpass = userpass_clear = malloc (length_userpass); + userpass_crypted = malloc (length_userpass); + memset (userpass_clear, 0, length_password); + memset (userpass_crypted, 0, length_password); + memcpy (ptr_userpass, sasl_username, length_username); + ptr_userpass += length_username; + memcpy (ptr_userpass, sasl_password, length_password); + + /* crypt password using AES in CBC mode */ + if (gcry_cipher_open (&gcrypt_handle, cipher_algo, + GCRY_CIPHER_MODE_CBC, 0) != 0) + goto aesend; + if (gcry_cipher_setkey (gcrypt_handle, secret_bin, length_key) != 0) + goto aesend; + if (gcry_cipher_setiv (gcrypt_handle, iv, sizeof(iv)) != 0) + goto aesend; + if (gcry_cipher_encrypt (gcrypt_handle, + userpass_crypted, length_userpass, + userpass_clear, length_userpass) != 0) + goto aesend; + + gcry_cipher_close (gcrypt_handle); + + /* + * build answer for server, it is concatenation of: + * 1. key length (2 bytes) + * 2. public key ('length_key' bytes) + * 3. IV (sizeof (iv) bytes) + * 4. encrypted password ('length_userpass' bytes) + */ + length_answer = 2 + length_key + sizeof (iv) + length_userpass; + answer = malloc (length_answer); + ptr_answer = answer; + *((unsigned int *)ptr_answer) = htons(length_key); + ptr_answer += 2; + memcpy (ptr_answer, public_bin, length_key); + ptr_answer += length_key; + memcpy (ptr_answer, iv, sizeof (iv)); + ptr_answer += sizeof (iv); + memcpy (ptr_answer, userpass_crypted, length_userpass); + + /* encode answer to base64 */ + answer_base64 = malloc (length_answer * 4); + if (answer_base64) + weechat_string_encode_base64 (answer, length_answer, answer_base64); + +aesend: + if (secret_bin) + free (secret_bin); + if (public_bin) + free (public_bin); + if (userpass_clear) + free (userpass_clear); + if (userpass_crypted) + free (userpass_crypted); + if (answer) + free (answer); return answer_base64; } |