X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fopenssl%2Fcipher.c;h=77747f11b7dd356c1ea8000444cf6ef2495affce;hb=dcf9e6c3e444fd39318f8d5b261bdc22e5031f67;hp=743449a33a498f70c7bdf9c37f54c3623ca0d386;hpb=3d75dbc0880484ff6d2f689a9b981def3cd75b5e;p=tinc diff --git a/src/openssl/cipher.c b/src/openssl/cipher.c index 743449a3..77747f11 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) 2007-2022 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 @@ -17,130 +17,196 @@ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "system.h" +#include "../system.h" -#include #include +#include +#include "log.h" #include "cipher.h" -#include "logger.h" -#include "xalloc.h" +#include "../cipher.h" +#include "../logger.h" -static bool cipher_open(cipher_t *cipher) { - EVP_CIPHER_CTX_init(&cipher->ctx); +static void cipher_open(cipher_t *cipher, const EVP_CIPHER *evp_cipher) { + cipher->cipher = evp_cipher; + cipher->ctx = EVP_CIPHER_CTX_new(); - return true; + if(!cipher->ctx) { + abort(); + } } bool cipher_open_by_name(cipher_t *cipher, const char *name) { - cipher->cipher = EVP_get_cipherbyname(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 false; + } - logger(LOG_ERR, "Unknown cipher name '%s'!", name); - return false; + cipher_open(cipher, evp_cipher); + return true; } bool cipher_open_by_nid(cipher_t *cipher, int nid) { - cipher->cipher = EVP_get_cipherbynid(nid); - - if(cipher->cipher) - return cipher_open(cipher); + const EVP_CIPHER *evp_cipher = EVP_get_cipherbynid(nid); - logger(LOG_ERR, "Unknown cipher nid %d!", nid); - return false; -} + if(!evp_cipher) { + logger(DEBUG_ALWAYS, LOG_ERR, "Unknown cipher nid %d!", nid); + return false; + } -bool cipher_open_blowfish_ofb(cipher_t *cipher) { - cipher->cipher = EVP_bf_ofb(); - return cipher_open(cipher); + cipher_open(cipher, evp_cipher); + return true; } void cipher_close(cipher_t *cipher) { - EVP_CIPHER_CTX_cleanup(&cipher->ctx); + if(!cipher) { + return; + } + + if(cipher->ctx) { + EVP_CIPHER_CTX_free(cipher->ctx); + } + + memset(cipher, 0, sizeof(*cipher)); } size_t cipher_keylength(const cipher_t *cipher) { - return cipher->cipher->key_len + cipher->cipher->iv_len; + if(!cipher || !cipher->cipher) { + return 0; + } + + return EVP_CIPHER_key_length(cipher->cipher) + EVP_CIPHER_iv_length(cipher->cipher); +} + +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(!cipher || !cipher->cipher) { + return UINT64_MAX; // NULL cipher + } + + 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; +} + +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(cipher_t *cipher, void *key, bool encrypt) { bool result; - if(encrypt) - result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len); - else - result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + cipher->cipher->key_len); + 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)); + openssl_err("set key"); return false; } bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encrypt) { bool result; - if(encrypt) - result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - cipher->cipher->key_len, (unsigned char *)key + len - cipher->cipher->iv_len - cipher->cipher->key_len); - else - result = EVP_DecryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key + len - cipher->cipher->key_len, (unsigned char *)key + len - cipher->cipher->iv_len - cipher->cipher->key_len); + 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 setting key: %s", ERR_error_string(ERR_get_error(), NULL)); + openssl_err("set key"); 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, 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)) { - if(outlen) *outlen = len + pad; + + if(EVP_EncryptInit_ex(cipher->ctx, NULL, NULL, NULL, NULL) + && EVP_EncryptUpdate(cipher->ctx, (unsigned char *)outdata, &len, indata, (int)inlen) + && EVP_EncryptFinal_ex(cipher->ctx, (unsigned char *)outdata + len, &pad)) { + if(outlen) { + *outlen = len + pad; + } + return true; } } else { int len; - if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) { - if(outlen) *outlen = len; + + if(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, (int)inlen)) { + if(outlen) { + *outlen = len; + } + return true; } } - logger(LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL)); + openssl_err("encrypt data"); 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, pad; - 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)) { - if(outlen) *outlen = len + pad; + + if(EVP_DecryptInit_ex(cipher->ctx, NULL, NULL, NULL, NULL) + && EVP_DecryptUpdate(cipher->ctx, (unsigned char *)outdata, &len, indata, (int)inlen) + && EVP_DecryptFinal_ex(cipher->ctx, (unsigned char *)outdata + len, &pad)) { + if(outlen) { + *outlen = len + pad; + } + return true; } } else { int len; - if(EVP_EncryptUpdate(&cipher->ctx, outdata, &len, indata, inlen)) { - if(outlen) *outlen = len; + + if(EVP_DecryptUpdate(cipher->ctx, outdata, &len, indata, (int)inlen)) { + if(outlen) { + *outlen = len; + } + return true; } } - logger(LOG_ERR, "Error while decrypting: %s", ERR_error_string(ERR_get_error(), NULL)); + openssl_err("decrypt data"); 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; }