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Diffstat (limited to 'Utilities/cmcurl/lib/rand.c')
| -rw-r--r-- | Utilities/cmcurl/lib/rand.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/rand.c b/Utilities/cmcurl/lib/rand.c new file mode 100644 index 0000000..3383c49 --- /dev/null +++ b/Utilities/cmcurl/lib/rand.c @@ -0,0 +1,289 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + * SPDX-License-Identifier: curl + * + ***************************************************************************/ + +#include "curl_setup.h" + +#include <limits.h> + +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif +#ifdef HAVE_ARPA_INET_H +#include <arpa/inet.h> +#endif + +#include <curl/curl.h> +#include "urldata.h" +#include "vtls/vtls.h" +#include "sendf.h" +#include "timeval.h" +#include "rand.h" +#include "escape.h" + +/* The last 3 #include files should be in this order */ +#include "curl_printf.h" +#include "curl_memory.h" +#include "memdebug.h" + +#ifdef _WIN32 + +#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600 +# define HAVE_WIN_BCRYPTGENRANDOM +# include <bcrypt.h> +# ifdef _MSC_VER +# pragma comment(lib, "bcrypt.lib") +# endif +# ifndef BCRYPT_USE_SYSTEM_PREFERRED_RNG +# define BCRYPT_USE_SYSTEM_PREFERRED_RNG 0x00000002 +# endif +# ifndef STATUS_SUCCESS +# define STATUS_SUCCESS ((NTSTATUS)0x00000000L) +# endif +#elif defined(USE_WIN32_CRYPTO) +# include <wincrypt.h> +# ifdef _MSC_VER +# pragma comment(lib, "advapi32.lib") +# endif +#endif + +CURLcode Curl_win32_random(unsigned char *entropy, size_t length) +{ + memset(entropy, 0, length); + +#if defined(HAVE_WIN_BCRYPTGENRANDOM) + if(BCryptGenRandom(NULL, entropy, (ULONG)length, + BCRYPT_USE_SYSTEM_PREFERRED_RNG) != STATUS_SUCCESS) + return CURLE_FAILED_INIT; + + return CURLE_OK; +#elif defined(USE_WIN32_CRYPTO) + { + HCRYPTPROV hCryptProv = 0; + + if(!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, + CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) + return CURLE_FAILED_INIT; + + if(!CryptGenRandom(hCryptProv, (DWORD)length, entropy)) { + CryptReleaseContext(hCryptProv, 0UL); + return CURLE_FAILED_INIT; + } + + CryptReleaseContext(hCryptProv, 0UL); + } + return CURLE_OK; +#else + return CURLE_NOT_BUILT_IN; +#endif +} +#endif + +static CURLcode randit(struct Curl_easy *data, unsigned int *rnd) +{ + CURLcode result = CURLE_OK; + static unsigned int randseed; + static bool seeded = FALSE; + +#ifdef CURLDEBUG + char *force_entropy = getenv("CURL_ENTROPY"); + if(force_entropy) { + if(!seeded) { + unsigned int seed = 0; + size_t elen = strlen(force_entropy); + size_t clen = sizeof(seed); + size_t min = elen < clen ? elen : clen; + memcpy((char *)&seed, force_entropy, min); + randseed = ntohl(seed); + seeded = TRUE; + } + else + randseed++; + *rnd = randseed; + return CURLE_OK; + } +#endif + + /* data may be NULL! */ + result = Curl_ssl_random(data, (unsigned char *)rnd, sizeof(*rnd)); + if(result != CURLE_NOT_BUILT_IN) + /* only if there is no random function in the TLS backend do the non crypto + version, otherwise return result */ + return result; + + /* ---- non-cryptographic version following ---- */ + +#ifdef _WIN32 + if(!seeded) { + result = Curl_win32_random((unsigned char *)rnd, sizeof(*rnd)); + if(result != CURLE_NOT_BUILT_IN) + return result; + } +#endif + +#if defined(HAVE_ARC4RANDOM) && !defined(USE_OPENSSL) + if(!seeded) { + *rnd = (unsigned int)arc4random(); + return CURLE_OK; + } +#endif + +#if defined(RANDOM_FILE) && !defined(_WIN32) + if(!seeded) { + /* if there's a random file to read a seed from, use it */ + int fd = open(RANDOM_FILE, O_RDONLY); + if(fd > -1) { + /* read random data into the randseed variable */ + ssize_t nread = read(fd, &randseed, sizeof(randseed)); + if(nread == sizeof(randseed)) + seeded = TRUE; + close(fd); + } + } +#endif + + if(!seeded) { + struct curltime now = Curl_now(); + infof(data, "WARNING: using weak random seed"); + randseed += (unsigned int)now.tv_usec + (unsigned int)now.tv_sec; + randseed = randseed * 1103515245 + 12345; + randseed = randseed * 1103515245 + 12345; + randseed = randseed * 1103515245 + 12345; + seeded = TRUE; + } + + { + unsigned int r; + /* Return an unsigned 32-bit pseudo-random number. */ + r = randseed = randseed * 1103515245 + 12345; + *rnd = (r << 16) | ((r >> 16) & 0xFFFF); + } + return CURLE_OK; +} + +/* + * Curl_rand() stores 'num' number of random unsigned characters in the buffer + * 'rnd' points to. + * + * If libcurl is built without TLS support or with a TLS backend that lacks a + * proper random API (rustls or mbedTLS), this function will use "weak" + * random. + * + * When built *with* TLS support and a backend that offers strong random, it + * will return error if it cannot provide strong random values. + * + * NOTE: 'data' may be passed in as NULL when coming from external API without + * easy handle! + * + */ + +CURLcode Curl_rand(struct Curl_easy *data, unsigned char *rnd, size_t num) +{ + CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT; + + DEBUGASSERT(num > 0); + + while(num) { + unsigned int r; + size_t left = num < sizeof(unsigned int) ? num : sizeof(unsigned int); + + result = randit(data, &r); + if(result) + return result; + + while(left) { + *rnd++ = (unsigned char)(r & 0xFF); + r >>= 8; + --num; + --left; + } + } + + return result; +} + +/* + * Curl_rand_hex() fills the 'rnd' buffer with a given 'num' size with random + * hexadecimal digits PLUS a null-terminating byte. It must be an odd number + * size. + */ + +CURLcode Curl_rand_hex(struct Curl_easy *data, unsigned char *rnd, + size_t num) +{ + CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT; + unsigned char buffer[128]; + DEBUGASSERT(num > 1); + +#ifdef __clang_analyzer__ + /* This silences a scan-build warning about accessing this buffer with + uninitialized memory. */ + memset(buffer, 0, sizeof(buffer)); +#endif + + if((num/2 >= sizeof(buffer)) || !(num&1)) + /* make sure it fits in the local buffer and that it is an odd number! */ + return CURLE_BAD_FUNCTION_ARGUMENT; + + num--; /* save one for null-termination */ + + result = Curl_rand(data, buffer, num/2); + if(result) + return result; + + Curl_hexencode(buffer, num/2, rnd, num + 1); + return result; +} + +/* + * Curl_rand_alnum() fills the 'rnd' buffer with a given 'num' size with random + * alphanumerical chars PLUS a null-terminating byte. + */ + +static const char alnum[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; + +CURLcode Curl_rand_alnum(struct Curl_easy *data, unsigned char *rnd, + size_t num) +{ + CURLcode result = CURLE_OK; + const int alnumspace = sizeof(alnum) - 1; + unsigned int r; + DEBUGASSERT(num > 1); + + num--; /* save one for null-termination */ + + while(num) { + do { + result = randit(data, &r); + if(result) + return result; + } while(r >= (UINT_MAX - UINT_MAX % alnumspace)); + + *rnd++ = alnum[r % alnumspace]; + num--; + } + *rnd = 0; + + return result; +} |
