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| -rw-r--r-- | nping/Crypto.cc | 279 |
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diff --git a/nping/Crypto.cc b/nping/Crypto.cc new file mode 100644 index 0000000..ab41175 --- /dev/null +++ b/nping/Crypto.cc @@ -0,0 +1,279 @@ + +/*************************************************************************** + * Crypto.cc -- The Crypto Class contains miscellaneous methods and helpers* + * that may be used to provide properties such as authentication, integrity* + * or confidentiality. * + * * + ***********************IMPORTANT NMAP LICENSE TERMS************************ + * + * The Nmap Security Scanner is (C) 1996-2023 Nmap Software LLC ("The Nmap + * Project"). Nmap is also a registered trademark of the Nmap Project. + * + * This program is distributed under the terms of the Nmap Public Source + * License (NPSL). The exact license text applying to a particular Nmap + * release or source code control revision is contained in the LICENSE + * file distributed with that version of Nmap or source code control + * revision. More Nmap copyright/legal information is available from + * https://nmap.org/book/man-legal.html, and further information on the + * NPSL license itself can be found at https://nmap.org/npsl/ . This + * header summarizes some key points from the Nmap license, but is no + * substitute for the actual license text. + * + * Nmap is generally free for end users to download and use themselves, + * including commercial use. It is available from https://nmap.org. + * + * The Nmap license generally prohibits companies from using and + * redistributing Nmap in commercial products, but we sell a special Nmap + * OEM Edition with a more permissive license and special features for + * this purpose. See https://nmap.org/oem/ + * + * If you have received a written Nmap license agreement or contract + * stating terms other than these (such as an Nmap OEM license), you may + * choose to use and redistribute Nmap under those terms instead. + * + * The official Nmap Windows builds include the Npcap software + * (https://npcap.com) for packet capture and transmission. It is under + * separate license terms which forbid redistribution without special + * permission. So the official Nmap Windows builds may not be redistributed + * without special permission (such as an Nmap OEM license). + * + * Source is provided to this software because we believe users have a + * right to know exactly what a program is going to do before they run it. + * This also allows you to audit the software for security holes. + * + * Source code also allows you to port Nmap to new platforms, fix bugs, and add + * new features. You are highly encouraged to submit your changes as a Github PR + * or by email to the dev@nmap.org mailing list for possible incorporation into + * the main distribution. Unless you specify otherwise, it is understood that + * you are offering us very broad rights to use your submissions as described in + * the Nmap Public Source License Contributor Agreement. This is important + * because we fund the project by selling licenses with various terms, and also + * because the inability to relicense code has caused devastating problems for + * other Free Software projects (such as KDE and NASM). + * + * The free version of Nmap is distributed in the hope that it will be + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Warranties, + * indemnification and commercial support are all available through the + * Npcap OEM program--see https://nmap.org/oem/ + * + ***************************************************************************/ +#include "nping.h" +#include "Crypto.h" +#include "output.h" +#include "NpingOps.h" + +#ifdef HAVE_OPENSSL +#include <openssl/hmac.h> +#include <openssl/evp.h> +#include <openssl/err.h> + +#if (OPENSSL_VERSION_NUMBER >= 0x10100000L) && !defined LIBRESSL_VERSION_NUMBER +#define HAVE_OPAQUE_EVP_PKEY 1 +#else +#define EVP_MD_CTX_new EVP_MD_CTX_create +#define EVP_MD_CTX_free EVP_MD_CTX_destroy +#define EVP_CIPHER_CTX_free EVP_CIPHER_CTX_cleanup +#endif + +#endif /* HAVE_OPENSSL */ + +extern NpingOps o; + +Crypto::Crypto(){ + this->reset(); +} /* End of Crypto constructor */ + + +Crypto::~Crypto(){ + +} /* End of Crypto destructor */ + + +/** Sets every attribute to its default value. */ +void Crypto::reset() { + +} /* End of reset() */ + + +int Crypto::hmac_sha256(u8 *inbuff, size_t inlen, u8 *dst_buff, u8 *key, size_t key_len){ + + #ifdef HAVE_OPENSSL + if( o.doCrypto() ){ + u8 result[EVP_MAX_MD_SIZE]; + memset(result, 0, EVP_MAX_MD_SIZE); + unsigned int result_len; + HMAC(EVP_sha256(), key, (int)key_len, inbuff, (int)inlen, result, &result_len); + memcpy(dst_buff, result, 256/8); + return OP_SUCCESS; + } + #endif + /* Set a bogus sum: all zero */ + memset(dst_buff, 0, HMAC_SHA256_CODE_LEN); + return OP_SUCCESS; +} /* End of hmac_sha256() */ + + +int Crypto::aes128_cbc_encrypt(u8 *inbuff, size_t inlen, u8 *dst_buff, u8 *key, size_t key_len, u8 *iv){ + nping_print(DBG_4, "%s(%p, %lu, %p, %p, %lu, %p)", __func__, inbuff, (unsigned long)inlen, dst_buff, key, (unsigned long)key_len, iv); + if(inbuff==NULL || dst_buff==NULL || key==NULL || iv==NULL) + return OP_FAILURE; + if( ((inlen%AES_BLOCK_SIZE)!=0) || key_len<AES_KEY_SIZE) + return OP_FAILURE; + + #ifdef HAVE_OPENSSL + if( o.doCrypto() ){ + int flen=0, flen2=0; + #if HAVE_OPAQUE_EVP_PKEY + EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new(); + #else + EVP_CIPHER_CTX stack_ctx; + EVP_CIPHER_CTX *ctx = &stack_ctx; + EVP_CIPHER_CTX_init(ctx); + #endif + EVP_CIPHER_CTX_set_padding(ctx, 0); + int result=OP_SUCCESS; + if( EVP_EncryptInit(ctx, EVP_aes_128_cbc(), key, iv)==0 ){ + nping_print(DBG_4, "EVP_EncryptInit() failed"); + result=OP_FAILURE; + }else if( EVP_EncryptUpdate(ctx, dst_buff, &flen, inbuff, (int)inlen)==0 ){ + nping_print(DBG_4, "EVP_EncryptUpdate() failed"); + result=OP_FAILURE; + }else if( EVP_EncryptFinal(ctx, dst_buff+flen, &flen2)==0 ){ + nping_print(DBG_4, "EVP_EncryptFinal() failed"); + result=OP_FAILURE; + } + EVP_CIPHER_CTX_free(ctx); + return result; + } + #endif + /* Do not encrypt, just set the plaintext */ + for(size_t i=0; i<inlen; i++) + dst_buff[i]=inbuff[i]; + return OP_SUCCESS; +} /* End of aes128_cbc_encrypt() */ + + +int Crypto::aes128_cbc_decrypt(u8 *inbuff, size_t inlen, u8 *dst_buff, u8 *key, size_t key_len, u8 *iv){ + nping_print(DBG_4, "%s(%p, %lu, %p, %p, %lu, %p)", __func__, inbuff, (unsigned long)inlen, dst_buff, key, (unsigned long)key_len, iv); + if(inbuff==NULL || dst_buff==NULL || key==NULL || iv==NULL) + return OP_FAILURE; + if( ((inlen%AES_BLOCK_SIZE)!=0) || key_len<AES_KEY_SIZE) + return OP_FAILURE; + + #ifdef HAVE_OPENSSL + if( o.doCrypto() ){ + int flen1=0, flen2=0; + #if HAVE_OPAQUE_EVP_PKEY + EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new(); + #else + EVP_CIPHER_CTX stack_ctx; + EVP_CIPHER_CTX *ctx = &stack_ctx; + EVP_CIPHER_CTX_init(ctx); + #endif + EVP_CIPHER_CTX_set_padding(ctx, 0); + int result=OP_SUCCESS; + if( EVP_DecryptInit(ctx, EVP_aes_128_cbc(), key, iv)==0 ){ + nping_print(DBG_4, "EVP_DecryptInit() failed"); + result=OP_FAILURE; + }else if( EVP_DecryptUpdate(ctx, dst_buff, &flen1, inbuff, (int)inlen)==0 ){ + nping_print(DBG_4, "EVP_DecryptUpdate() failed"); + result=OP_FAILURE; + }else if( EVP_DecryptFinal(ctx, dst_buff+flen1, &flen2)==0 ){ + nping_print(DBG_4, "OpenSSL bug: it says EVP_DecryptFinal() failed when it didn't (%s).", + ERR_error_string(ERR_peek_last_error(), NULL)); + /* We do not return OP_FAILURE in this case because the + * EVP_DecryptFinal() function seems to be buggy and fails when it shouldn't. + * We are passing a buffer whose length is multiple of the AES block + * size, we've disable padding, and still, the call fails. + * The call to EVP_DecryptUpdate() says we've decrypted all blocks but + * the last one and then EVP_DecryptFinal says we have decrypted nothing. + * However I've tested this for hours and everything works fine. The + * full buffer is decrypted correctly, from the first to the last byte, + * so we return OP_SUCCESS even if OpenSSL says the opposite. */ + + /* NOTE for developers debugging memory issues with Valgrind: + * None of these seems to free OpenSSL's internal error structures. + * Valgrind currently reports things like: + ==12849== 592 bytes in 1 blocks are still reachable in loss record 7 of 9 + ==12849== at 0x4C284A8: malloc (vg_replace_malloc.c:236) + ==12849== by 0x531BF21: CRYPTO_malloc (in /lib/libcrypto.so.0.9.8) + ==12849== by 0x537F25D: ERR_get_state (in /lib/libcrypto.so.0.9.8) + ==12849== by 0x537E7BE: ERR_put_error (in /lib/libcrypto.so.0.9.8) + ==12849== by 0x5381EB0: EVP_DecryptFinal_ex (in /lib/libcrypto.so.0.9.8) + ==12849== by 0x429A49: Crypto::aes128_cbc_decrypt(unsigned char*... + ==12849== by 0x41ABBA: EchoHeader::decrypt(unsigned char*, unsign... + */ + //ERR_clear_error(); + //ERR_free_strings(); + //ERR_pop_to_mark(); + } + EVP_CIPHER_CTX_free(ctx); + return result; + } + #endif + /* Do not decrypt, just leave the ciphertext */ + for(size_t i=0; i<inlen; i++) + dst_buff[i]=inbuff[i]; + return OP_SUCCESS; +} /* End of aes128_cbc_decrypt() */ + + +int Crypto::generateNonce(u8 *dst_buff, size_t bufflen){ + nping_print(DBG_4, "%s()", __func__); + if(dst_buff==NULL || bufflen<=0) + return OP_FAILURE; + #ifdef HAVE_OPENSSL + // Get cryptographically secure random data from OpenSSL + // @todo TODO finish this. + get_random_bytes(dst_buff, bufflen); /* Provided by nbase */ + #else + get_random_bytes(dst_buff, bufflen); /* Provided by nbase */ + #endif + return OP_SUCCESS; +} /* End of generateNonce() */ + + +#define TIMES_KEY_DERIVATION 1000 +u8 *Crypto::deriveKey(const u8 *from, size_t fromlen, size_t *final_len){ + nping_print(DBG_4, "%s()", __func__); + if(from==NULL || fromlen==0) + return NULL; + + #ifdef HAVE_OPENSSL + if( o.doCrypto() ){ + static u8 hash[MAX(SHA256_HASH_LEN, EVP_MAX_MD_SIZE)]; + static u8 next[MAX(SHA256_HASH_LEN, EVP_MAX_MD_SIZE)]; + unsigned int lastlen; + EVP_MD_CTX *ctx = EVP_MD_CTX_new(); + + if( EVP_MD_size(EVP_sha256()) != SHA256_HASH_LEN ) + nping_fatal(QT_2, "OpenSSL is broken. SHA256 len is %d\n", EVP_MD_size(EVP_sha256()) ); + + /* Compute the SHA256 hash of the supplied buffer */ + EVP_DigestInit(ctx, EVP_sha256()); + EVP_DigestUpdate(ctx, from, fromlen); + EVP_DigestFinal(ctx, hash, &lastlen); + + /* Now compute the 1000th hash of that hash */ + for(int i=0; i<TIMES_KEY_DERIVATION; i++){ + EVP_MD_CTX_init(ctx); + EVP_DigestInit(ctx, EVP_sha256()); + EVP_DigestUpdate(ctx, hash, SHA256_HASH_LEN); + EVP_DigestFinal(ctx, next, &lastlen); + memcpy(hash, next, SHA256_HASH_LEN); + } + if(final_len!=NULL) + *final_len=SHA256_HASH_LEN; + + EVP_MD_CTX_free(ctx); + return hash; + } + #endif + static u8 zerohash[SHA256_HASH_LEN]; + memset(zerohash, 0, SHA256_HASH_LEN); + if(final_len!=NULL) + *final_len=SHA256_HASH_LEN; + return zerohash; + +} /* End of deriveKey() */ |