/*
cipher.c -- Symmetric block cipher handling
- Copyright (C) 2007 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2007-2013 Guus Sliepen <guus@tinc-vpn.org>
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
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#include "system.h"
+#include "../system.h"
#include <openssl/rand.h>
#include <openssl/err.h>
+#include <openssl/evp.h>
-#include "cipher.h"
-#include "logger.h"
-#include "xalloc.h"
+#include "../cipher.h"
+#include "../logger.h"
+#include "../xalloc.h"
-static bool cipher_open(cipher_t *cipher) {
+struct cipher {
+ EVP_CIPHER_CTX ctx;
+ const EVP_CIPHER *cipher;
+ struct cipher_counter *counter;
+};
+
+typedef struct cipher_counter {
+ unsigned char counter[CIPHER_MAX_IV_SIZE];
+ unsigned char block[CIPHER_MAX_IV_SIZE];
+ int n;
+} cipher_counter_t;
+
+static cipher_t *cipher_open(const EVP_CIPHER *evp_cipher) {
+ cipher_t *cipher = xzalloc(sizeof *cipher);
+ cipher->cipher = evp_cipher;
EVP_CIPHER_CTX_init(&cipher->ctx);
- return true;
+ return cipher;
}
-bool cipher_open_by_name(cipher_t *cipher, const char *name) {
- cipher->cipher = EVP_get_cipherbyname(name);
-
- if(cipher->cipher)
- return cipher_open(cipher);
+cipher_t *cipher_open_by_name(const char *name) {
+ const EVP_CIPHER *evp_cipher = EVP_get_cipherbyname(name);
+ if(!evp_cipher) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher name '%s'!", name);
+ return NULL;
+ }
- logger(LOG_ERR, "Unknown cipher name '%s'!", name);
- return false;
+ return cipher_open(evp_cipher);
}
-bool cipher_open_by_nid(cipher_t *cipher, int nid) {
- cipher->cipher = EVP_get_cipherbynid(nid);
-
- if(cipher->cipher)
- return cipher_open(cipher);
+cipher_t *cipher_open_by_nid(int nid) {
+ const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid);
+ if(!evp_cipher) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid);
+ return NULL;
+ }
- logger(LOG_ERR, "Unknown cipher nid %d!", nid);
- return false;
+ return cipher_open(evp_cipher);
}
-bool cipher_open_blowfish_ofb(cipher_t *cipher) {
- cipher->cipher = EVP_bf_ofb();
- return cipher_open(cipher);
+cipher_t *cipher_open_blowfish_ofb(void) {
+ return cipher_open(EVP_bf_ofb());
}
void cipher_close(cipher_t *cipher) {
+ if(!cipher)
+ return;
+
EVP_CIPHER_CTX_cleanup(&cipher->ctx);
+ free(cipher->counter);
+ free(cipher);
}
size_t cipher_keylength(const cipher_t *cipher) {
+ if(!cipher || !cipher->cipher)
+ return 0;
+
return cipher->cipher->key_len + cipher->cipher->iv_len;
}
if(result)
return true;
- logger(LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
return false;
}
if(result)
return true;
- logger(LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
return false;
}
+bool cipher_set_counter(cipher_t *cipher, const void *counter, size_t len) {
+ if(len > cipher->cipher->iv_len - 4) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Counter too long");
+ return false;
+ }
+
+ memcpy(cipher->counter->counter, counter, len);
+ cipher->counter->n = 0;
+
+ return true;
+}
+
+bool cipher_set_counter_key(cipher_t *cipher, void *key) {
+ int result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, NULL);
+ if(!result) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+
+ if(!cipher->counter)
+ cipher->counter = xzalloc(sizeof *cipher->counter);
+ else
+ cipher->counter->n = 0;
+
+ memcpy(cipher->counter->counter, (unsigned char *)key + cipher->cipher->key_len, cipher->cipher->iv_len);
+
+ return true;
+}
+
+bool cipher_gcm_encrypt_start(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ int len = 0;
+ if(!EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)
+ || (inlen && !EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ if(outlen)
+ *outlen = len;
+ return true;
+}
+
+bool cipher_gcm_encrypt_finish(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ int len = 0, pad = 0;
+ if(!(inlen && EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))
+ || !EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_GET_TAG, 16, (unsigned char *)outdata + len + pad);
+ if(outlen)
+ *outlen = len + pad + 16;
+ return true;
+}
+
+bool cipher_gcm_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ int len = 0, pad = 0;
+ if(!EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter) ||
+ !EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen) ||
+ !EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_GET_TAG, 16, (unsigned char *)outdata + len + pad);
+ if(outlen)
+ *outlen = len + pad + 16;
+ return true;
+}
+
+bool cipher_gcm_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ if(inlen < 16)
+ return false;
+
+ int len = 0, pad = 0;
+ if(!EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+
+ EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_SET_TAG, 16, (unsigned char *)indata + inlen - 16);
+
+ if(!EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen - 16) ||
+ !EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ if(outlen)
+ *outlen = len;
+ return true;
+}
+
+bool cipher_gcm_decrypt_start(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ int len = 0;
+ if(!EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, cipher->counter->counter)
+ || (inlen && !EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ if(outlen)
+ *outlen = len;
+ return true;
+}
+
+bool cipher_gcm_decrypt_finish(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen) {
+ if(inlen < 16)
+ return false;
+
+ EVP_CIPHER_CTX_ctrl(&cipher->ctx, EVP_CTRL_GCM_SET_TAG, 16, (unsigned char *)indata + inlen - 16);
+
+ int len = 0, pad = 0;
+ if((inlen > 16 && !EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, (unsigned char *)indata, inlen - 16))
+ || !EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ return true;
+}
+
+
bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) {
if(oneshot) {
int len, pad;
if(EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
&& EVP_EncryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
&& EVP_EncryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
- *outlen = len + pad;
+ if(outlen) *outlen = len + pad;
return true;
}
} else {
int len;
if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
- *outlen = len;
+ if(outlen) *outlen = len;
return true;
}
}
- logger(LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
return false;
}
if(EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL)
&& EVP_DecryptUpdate(&cipher->ctx, (unsigned char *)outdata, &len, indata, inlen)
&& EVP_DecryptFinal(&cipher->ctx, (unsigned char *)outdata + len, &pad)) {
- *outlen = len + pad;
+ if(outlen) *outlen = len + pad;
return true;
}
} else {
int len;
if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) {
- *outlen = len;
+ if(outlen) *outlen = len;
return true;
}
}
- logger(LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL));
return false;
}
int cipher_get_nid(const cipher_t *cipher) {
- return cipher->cipher ? cipher->cipher->nid : 0;
+ if(!cipher || !cipher->cipher)
+ return 0;
+
+ return cipher->cipher->nid;
}
bool cipher_active(const cipher_t *cipher) {
- return cipher->cipher && cipher->cipher->nid != 0;
+ return cipher && cipher->cipher && cipher->cipher->nid != 0;
}