/*
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"
+
+struct cipher {
+ EVP_CIPHER_CTX ctx;
+ const EVP_CIPHER *cipher;
+ struct cipher_counter *counter;
+};
typedef struct cipher_counter {
- unsigned char counter[EVP_MAX_IV_LENGTH];
- unsigned char block[EVP_MAX_IV_LENGTH];
+ unsigned char counter[CIPHER_MAX_IV_SIZE];
+ unsigned char block[CIPHER_MAX_IV_SIZE];
int n;
} cipher_counter_t;
-static bool cipher_open(cipher_t *cipher) {
+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(DEBUG_ALWAYS, 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(DEBUG_ALWAYS, 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);
- if(cipher->counter) {
- free(cipher->counter);
- cipher->counter = 0;
- }
+ free(cipher->counter);
+ free(cipher);
}
size_t cipher_keylength(const cipher_t *cipher) {
- return cipher->cipher->key_len + cipher->cipher->block_size;
+ if(!cipher || !cipher->cipher)
+ return 0;
+
+ return cipher->cipher->key_len + cipher->cipher->iv_len;
}
bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) {
}
bool cipher_set_counter(cipher_t *cipher, const void *counter, size_t len) {
- if(len > cipher->cipher->block_size - 4) {
+ if(len > cipher->cipher->iv_len - 4) {
logger(DEBUG_ALWAYS, LOG_ERR, "Counter too long");
- abort();
+ return false;
}
- memcpy(cipher->counter->counter + cipher->cipher->block_size - len, counter, len);
- memset(cipher->counter->counter, 0, 4);
+ memcpy(cipher->counter->counter, counter, len);
cipher->counter->n = 0;
return true;
}
if(!cipher->counter)
- cipher->counter = xmalloc_and_zero(sizeof *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->block_size);
+ memcpy(cipher->counter->counter, (unsigned char *)key + cipher->cipher->key_len, cipher->cipher->iv_len);
return true;
}
-bool cipher_counter_xor(cipher_t *cipher, const void *indata, size_t inlen, void *outdata) {
- if(!cipher->counter) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Counter not initialized");
+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;
+}
- const unsigned char *in = indata;
- unsigned char *out = outdata;
-
- while(inlen--) {
- // Encrypt the new counter value if we need it
- if(!cipher->counter->n) {
- int len;
- if(!EVP_EncryptUpdate(&cipher->ctx, cipher->counter->block, &len, cipher->counter->counter, cipher->cipher->block_size)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
- return false;
- }
-
- // Increase the counter value
- for(int i = 0; i < cipher->cipher->block_size; i++)
- if(++cipher->counter->counter[i])
- break;
- }
+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;
+}
- *out++ = *in++ ^ cipher->counter->counter[cipher->counter->n++];
+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;
- if(cipher->counter->n >= cipher->cipher->block_size)
- cipher->counter->n = 0;
+ 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;
}
}
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;
}
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