X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;ds=sidebyside;f=src%2Fopenssl%2Fcipher.c;h=974fbeb2e9966e1d189fa6c7737aa63aa1e1a025;hb=2b0aeec02d64bb4724da9ff1dbc19b7d35d7c904;hp=9b39a28836c151a81d039ce74c80694e5fddb51a;hpb=b78436ff1e9afd767c3da473d34b7553d8411b6a;p=tinc diff --git a/src/openssl/cipher.c b/src/openssl/cipher.c index 9b39a288..974fbeb2 100644 --- a/src/openssl/cipher.c +++ b/src/openssl/cipher.c @@ -1,6 +1,6 @@ /* cipher.c -- Symmetric block cipher handling - Copyright (C) 2007-2013 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 @@ -28,20 +28,25 @@ #include "../xalloc.h" struct cipher { - EVP_CIPHER_CTX ctx; + EVP_CIPHER_CTX *ctx; const EVP_CIPHER *cipher; }; static cipher_t *cipher_open(const EVP_CIPHER *evp_cipher) { - cipher_t *cipher = xzalloc(sizeof *cipher); + cipher_t *cipher = xzalloc(sizeof(*cipher)); cipher->cipher = evp_cipher; - EVP_CIPHER_CTX_init(&cipher->ctx); + cipher->ctx = EVP_CIPHER_CTX_new(); + + if(!cipher->ctx) { + abort(); + } return 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; @@ -52,6 +57,7 @@ cipher_t *cipher_open_by_name(const char *name) { 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; @@ -60,35 +66,62 @@ cipher_t *cipher_open_by_nid(int nid) { return cipher_open(evp_cipher); } -cipher_t *cipher_open_blowfish_ofb(void) { - return cipher_open(EVP_bf_ofb()); -} - void cipher_close(cipher_t *cipher) { - if(!cipher) + if(!cipher) { return; + } - EVP_CIPHER_CTX_cleanup(&cipher->ctx); + EVP_CIPHER_CTX_free(cipher->ctx); free(cipher); } size_t cipher_keylength(const cipher_t *cipher) { - if(!cipher || !cipher->cipher) + 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 cipher->cipher->key_len + cipher->cipher->iv_len; + 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(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL)); return false; @@ -97,13 +130,15 @@ bool cipher_set_key(cipher_t *cipher, void *key, bool encrypt) { 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(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL)); return false; @@ -112,16 +147,24 @@ bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encry 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, 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, inlen)) { + if(outlen) { + *outlen = len; + } + return true; } } @@ -133,16 +176,24 @@ bool cipher_encrypt(cipher_t *cipher, const void *indata, size_t inlen, void *ou 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, 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, inlen)) { + if(outlen) { + *outlen = len; + } + return true; } } @@ -152,12 +203,13 @@ bool cipher_decrypt(cipher_t *cipher, const void *indata, size_t inlen, void *ou } int cipher_get_nid(const cipher_t *cipher) { - if(!cipher || !cipher->cipher) + if(!cipher || !cipher->cipher) { return 0; + } - return cipher->cipher->nid; + return EVP_CIPHER_nid(cipher->cipher); } bool cipher_active(const cipher_t *cipher) { - return cipher && cipher->cipher && cipher->cipher->nid != 0; + return cipher && cipher->cipher && EVP_CIPHER_nid(cipher->cipher) != 0; }