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Diffstat (limited to 'libs/libcurl/src/rand.c')
| -rw-r--r-- | libs/libcurl/src/rand.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/libs/libcurl/src/rand.c b/libs/libcurl/src/rand.c new file mode 100644 index 0000000000..2670af9d97 --- /dev/null +++ b/libs/libcurl/src/rand.c @@ -0,0 +1,179 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2017, 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.haxx.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. + * + ***************************************************************************/ + +#include "curl_setup.h" + +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif + +#include <curl/curl.h> +#include "vtls/vtls.h" +#include "sendf.h" +#include "rand.h" + +/* The last 3 #include files should be in this order */ +#include "curl_printf.h" +#include "curl_memory.h" +#include "memdebug.h" + +static CURLcode randit(struct Curl_easy *data, unsigned int *rnd) +{ + unsigned int r; + 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 RANDOM_FILE + 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\n"); + 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; + } + + /* 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 integers in the buffer + * 'rndptr' points to. + * + * If libcurl is built without TLS support or with a TLS backend that lacks a + * proper random API (Gskit, PolarSSL 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 zero 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; + const char *hex = "0123456789abcdef"; + unsigned char buffer[128]; + unsigned char *bufp = buffer; + DEBUGASSERT(num > 1); + + 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 zero termination */ + + result = Curl_rand(data, buffer, num/2); + if(result) + return result; + + while(num) { + *rnd++ = hex[(*bufp & 0xF0)>>4]; + *rnd++ = hex[*bufp & 0x0F]; + bufp++; + num -= 2; + } + *rnd = 0; + + return result; +} |