X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fopenssl%2Fcipher.c;h=974fbeb2e9966e1d189fa6c7737aa63aa1e1a025;hb=2b0aeec02d64bb4724da9ff1dbc19b7d35d7c904;hp=e5fe07d93401588265a3419db04b01053936316f;hpb=103543aa2c15d9f1e2aa313a2e593a7524cce484;p=tinc diff --git a/src/openssl/cipher.c b/src/openssl/cipher.c index e5fe07d9..974fbeb2 100644 --- a/src/openssl/cipher.c +++ b/src/openssl/cipher.c @@ -1,6 +1,6 @@ /* cipher.c -- Symmetric block cipher handling - Copyright (C) 2007 Guus Sliepen + Copyright (C) 2007-2017 Guus Sliepen 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 @@ -17,164 +17,199 @@ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "system.h" +#include "../system.h" #include #include +#include -#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) { - cipher->keylen = cipher->cipher->key_len; - cipher->blklen = cipher->cipher->iv_len; +struct cipher { + EVP_CIPHER_CTX *ctx; + const EVP_CIPHER *cipher; +}; - cipher->key = xmalloc(cipher->keylen + cipher->blklen); +static cipher_t *cipher_open(const EVP_CIPHER *evp_cipher) { + cipher_t *cipher = xzalloc(sizeof(*cipher)); + cipher->cipher = evp_cipher; + cipher->ctx = EVP_CIPHER_CTX_new(); - EVP_CIPHER_CTX_init(&cipher->ctx); + if(!cipher->ctx) { + abort(); + } - return true; + return cipher; } -bool cipher_open_by_name(cipher_t *cipher, const char *name) { - cipher->cipher = EVP_get_cipherbyname(name); +cipher_t *cipher_open_by_name(const char *name) { + const EVP_CIPHER *evp_cipher = EVP_get_cipherbyname(name); - if(cipher->cipher) - return cipher_open(cipher); + if(!evp_cipher) { + logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher name '%s'!", name); + return NULL; + } - logger(LOG_DEBUG, "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); +cipher_t *cipher_open_by_nid(int nid) { + const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid); - if(cipher->cipher) - return cipher_open(cipher); - - logger(LOG_DEBUG, "Unknown cipher nid %d!", nid); - return false; -} + if(!evp_cipher) { + logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid); + return NULL; + } -bool cipher_open_blowfish_ofb(cipher_t *cipher) { - cipher->cipher = EVP_bf_ofb(); - return cipher_open(cipher); + return cipher_open(evp_cipher); } void cipher_close(cipher_t *cipher) { - EVP_CIPHER_CTX_cleanup(&cipher->ctx); - - if(cipher->key) { - free(cipher->key); - cipher->key = NULL; + if(!cipher) { + return; } + + EVP_CIPHER_CTX_free(cipher->ctx); + free(cipher); } size_t cipher_keylength(const cipher_t *cipher) { - return cipher->keylen + cipher->blklen; -} + if(!cipher || !cipher->cipher) { + return 0; + } -void cipher_get_key(const cipher_t *cipher, void *key) { - memcpy(key, cipher->key, cipher->keylen + cipher->blklen); + return EVP_CIPHER_key_length(cipher->cipher) + EVP_CIPHER_iv_length(cipher->cipher); } -bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) { - memcpy(cipher->key, key, cipher->keylen + cipher->blklen); - bool result; +uint64_t cipher_budget(const cipher_t *cipher) { + /* Hopefully some failsafe way to calculate the maximum amount of bytes to + send/receive with a given cipher before we might run into birthday paradox + attacks. Because we might use different modes, the block size of the mode + might be 1 byte. In that case, use the IV length. Ensure the whole thing + is limited to what can be represented with a 64 bits integer. + */ - if(encrypt) - result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); - else - result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); + if(!cipher || !cipher->cipher) { + return UINT64_MAX; // NULL cipher + } - if(result) - return true; + int ivlen = EVP_CIPHER_iv_length(cipher->cipher); + int blklen = EVP_CIPHER_block_size(cipher->cipher); + int len = blklen > 1 ? blklen : ivlen > 1 ? ivlen : 8; + int bits = len * 4 - 1; + return bits < 64 ? UINT64_C(1) << bits : UINT64_MAX; +} - logger(LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL)); - return false; +size_t cipher_blocksize(const cipher_t *cipher) { + if(!cipher || !cipher->cipher) { + return 1; + } + + return EVP_CIPHER_block_size(cipher->cipher); } -bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) { - memcpy(cipher->key, key + len - (size_t)cipher->keylen, cipher->keylen); - memcpy(cipher->key + cipher->keylen, key + len - (size_t)cipher->keylen - (size_t)cipher->blklen, cipher->blklen); +bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) { bool result; - if(encrypt) - result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); - else - result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); + if(encrypt) { + result = EVP_EncryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + EVP_CIPHER_key_length(cipher->cipher)); + } else { + result = EVP_DecryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + EVP_CIPHER_key_length(cipher->cipher)); + } - if(result) + 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_regenerate_key(cipher_t *cipher, bool encrypt) { +bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) { bool result; - RAND_pseudo_bytes((unsigned char *)cipher->key, cipher->keylen + cipher->blklen); - - if(encrypt) - result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); - else - result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)cipher->key, (unsigned char *)cipher->key + cipher->keylen); + if(encrypt) { + result = EVP_EncryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - EVP_CIPHER_key_length(cipher->cipher), (unsigned char *)key + len - EVP_CIPHER_iv_length(cipher->cipher) - EVP_CIPHER_key_length(cipher->cipher)); + } else { + result = EVP_DecryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - EVP_CIPHER_key_length(cipher->cipher), (unsigned char *)key + len - EVP_CIPHER_iv_length(cipher->cipher) - EVP_CIPHER_key_length(cipher->cipher)); + } - if(result) + if(result) { return true; - - logger(LOG_ERR, "Error while regenerating 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_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) { if(oneshot) { - int len = *outlen, pad; - if(EVP_EncryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL) - &&EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen) - && EVP_EncryptFinal(&cipher->ctx, outdata + len, &pad)) { - *outlen = len + pad; + 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_ex(cipher->ctx, (unsigned char *)outdata + len, &pad)) { + if(outlen) { + *outlen = len + pad; + } + return true; } } else { - int len = *outlen; - if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) { - *outlen = len; + int len; + + if(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) { + 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; } bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *outdata, size_t *outlen, bool oneshot) { if(oneshot) { - int len = *outlen, pad; - if(EVP_DecryptInit_ex(&cipher->ctx, NULL, NULL, NULL, NULL) - && EVP_DecryptUpdate(&cipher->ctx, outdata, &len, indata, inlen) - && EVP_DecryptFinal(&cipher->ctx, outdata + len, &pad)) { - *outlen = len + pad; + int len, pad; + + if(EVP_DecryptInit_ex(cipher->ctx, NULL, NULL, NULL, NULL) + && EVP_DecryptUpdate(cipher->ctx, (unsigned char *)outdata, &len, indata, inlen) + && EVP_DecryptFinal_ex(cipher->ctx, (unsigned char *)outdata + len, &pad)) { + if(outlen) { + *outlen = len + pad; + } + return true; } } else { - int len = *outlen; - if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) { - *outlen = len; + int len; + + if(EVP_DecryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) { + 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 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 EVP_CIPHER_nid(cipher->cipher); } bool cipher_active(const cipher_t *cipher) { - return cipher->cipher && cipher->cipher->nid != 0; + return cipher && cipher->cipher && EVP_CIPHER_nid(cipher->cipher) != 0; }