X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fopenssl%2Fcipher.c;h=98033c5e692057986ba010e1ad176a4474be2f27;hb=refs%2Ftags%2Frelease-1.1pre15;hp=04aee27e4c55fad2f9244fbac28b1a3a6e1d8f7f;hpb=0209f12d27d29f3aedc09b228bd289305851c75d;p=tinc diff --git a/src/openssl/cipher.c b/src/openssl/cipher.c index 04aee27e..98033c5e 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 @@ -28,14 +28,16 @@ #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->cipher = evp_cipher; - EVP_CIPHER_CTX_init(&cipher->ctx); + cipher->ctx = EVP_CIPHER_CTX_new(); + if(!cipher->ctx) + abort(); return cipher; } @@ -60,15 +62,11 @@ 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) return; - EVP_CIPHER_CTX_cleanup(&cipher->ctx); + EVP_CIPHER_CTX_free(cipher->ctx); free(cipher); } @@ -76,23 +74,41 @@ size_t cipher_keylength(const cipher_t *cipher) { if(!cipher || !cipher->cipher) return 0; - return cipher->cipher->key_len + cipher->cipher->iv_len; + 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->block_size; + 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); + 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 + cipher->cipher->key_len); + result = EVP_DecryptInit_ex(cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, (unsigned char *)key + EVP_CIPHER_key_length(cipher->cipher)); if(result) return true; @@ -105,9 +121,9 @@ bool cipher_set_key_from_rsa(cipher_t *cipher, void *key, size_t len, bool encry 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); + 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 - cipher->cipher->key_len, (unsigned char *)key + len - cipher->cipher->iv_len - cipher->cipher->key_len); + 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) return true; @@ -119,15 +135,15 @@ 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(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(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) { if(outlen) *outlen = len; return true; } @@ -140,15 +156,15 @@ 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(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(EVP_EncryptUpdate(cipher->ctx, outdata, &len, indata, inlen)) { if(outlen) *outlen = len; return true; } @@ -162,9 +178,9 @@ int cipher_get_nid(const cipher_t *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; }