[337] | 1 | /***************************************************************************
|
---|
| 2 | * _ _ ____ _
|
---|
| 3 | * Project ___| | | | _ \| |
|
---|
| 4 | * / __| | | | |_) | |
|
---|
| 5 | * | (__| |_| | _ <| |___
|
---|
| 6 | * \___|\___/|_| \_\_____|
|
---|
| 7 | *
|
---|
| 8 | * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
|
---|
| 9 | *
|
---|
| 10 | * This software is licensed as described in the file COPYING, which
|
---|
| 11 | * you should have received as part of this distribution. The terms
|
---|
| 12 | * are also available at https://curl.haxx.se/docs/copyright.html.
|
---|
| 13 | *
|
---|
| 14 | * You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
---|
| 15 | * copies of the Software, and permit persons to whom the Software is
|
---|
| 16 | * furnished to do so, under the terms of the COPYING file.
|
---|
| 17 | *
|
---|
| 18 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
---|
| 19 | * KIND, either express or implied.
|
---|
| 20 | *
|
---|
| 21 | ***************************************************************************/
|
---|
| 22 |
|
---|
| 23 | #include "curl_setup.h"
|
---|
| 24 |
|
---|
| 25 | #ifdef HAVE_FCNTL_H
|
---|
| 26 | #include <fcntl.h>
|
---|
| 27 | #endif
|
---|
| 28 |
|
---|
| 29 | #include <curl/curl.h>
|
---|
| 30 | #include "vtls/vtls.h"
|
---|
| 31 | #include "sendf.h"
|
---|
| 32 | #include "rand.h"
|
---|
| 33 |
|
---|
| 34 | /* The last 3 #include files should be in this order */
|
---|
| 35 | #include "curl_printf.h"
|
---|
| 36 | #include "curl_memory.h"
|
---|
| 37 | #include "memdebug.h"
|
---|
| 38 |
|
---|
| 39 | static CURLcode randit(struct Curl_easy *data, unsigned int *rnd)
|
---|
| 40 | {
|
---|
| 41 | unsigned int r;
|
---|
| 42 | CURLcode result = CURLE_OK;
|
---|
| 43 | static unsigned int randseed;
|
---|
| 44 | static bool seeded = FALSE;
|
---|
| 45 |
|
---|
| 46 | #ifdef CURLDEBUG
|
---|
| 47 | char *force_entropy = getenv("CURL_ENTROPY");
|
---|
| 48 | if(force_entropy) {
|
---|
| 49 | if(!seeded) {
|
---|
| 50 | unsigned int seed = 0;
|
---|
| 51 | size_t elen = strlen(force_entropy);
|
---|
| 52 | size_t clen = sizeof(seed);
|
---|
| 53 | size_t min = elen < clen ? elen : clen;
|
---|
| 54 | memcpy((char *)&seed, force_entropy, min);
|
---|
| 55 | randseed = ntohl(seed);
|
---|
| 56 | seeded = TRUE;
|
---|
| 57 | }
|
---|
| 58 | else
|
---|
| 59 | randseed++;
|
---|
| 60 | *rnd = randseed;
|
---|
| 61 | return CURLE_OK;
|
---|
| 62 | }
|
---|
| 63 | #endif
|
---|
| 64 |
|
---|
| 65 | /* data may be NULL! */
|
---|
| 66 | result = Curl_ssl_random(data, (unsigned char *)rnd, sizeof(*rnd));
|
---|
| 67 | if(result != CURLE_NOT_BUILT_IN)
|
---|
| 68 | /* only if there is no random function in the TLS backend do the non crypto
|
---|
| 69 | version, otherwise return result */
|
---|
| 70 | return result;
|
---|
| 71 |
|
---|
| 72 | /* ---- non-cryptographic version following ---- */
|
---|
| 73 |
|
---|
| 74 | #ifdef RANDOM_FILE
|
---|
| 75 | if(!seeded) {
|
---|
| 76 | /* if there's a random file to read a seed from, use it */
|
---|
| 77 | int fd = open(RANDOM_FILE, O_RDONLY);
|
---|
| 78 | if(fd > -1) {
|
---|
| 79 | /* read random data into the randseed variable */
|
---|
| 80 | ssize_t nread = read(fd, &randseed, sizeof(randseed));
|
---|
| 81 | if(nread == sizeof(randseed))
|
---|
| 82 | seeded = TRUE;
|
---|
| 83 | close(fd);
|
---|
| 84 | }
|
---|
| 85 | }
|
---|
| 86 | #endif
|
---|
| 87 |
|
---|
| 88 | if(!seeded) {
|
---|
| 89 | struct curltime now = Curl_now();
|
---|
| 90 | infof(data, "WARNING: Using weak random seed\n");
|
---|
| 91 | randseed += (unsigned int)now.tv_usec + (unsigned int)now.tv_sec;
|
---|
| 92 | randseed = randseed * 1103515245 + 12345;
|
---|
| 93 | randseed = randseed * 1103515245 + 12345;
|
---|
| 94 | randseed = randseed * 1103515245 + 12345;
|
---|
| 95 | seeded = TRUE;
|
---|
| 96 | }
|
---|
| 97 |
|
---|
| 98 | /* Return an unsigned 32-bit pseudo-random number. */
|
---|
| 99 | r = randseed = randseed * 1103515245 + 12345;
|
---|
| 100 | *rnd = (r << 16) | ((r >> 16) & 0xFFFF);
|
---|
| 101 | return CURLE_OK;
|
---|
| 102 | }
|
---|
| 103 |
|
---|
| 104 | /*
|
---|
| 105 | * Curl_rand() stores 'num' number of random unsigned integers in the buffer
|
---|
| 106 | * 'rndptr' points to.
|
---|
| 107 | *
|
---|
| 108 | * If libcurl is built without TLS support or with a TLS backend that lacks a
|
---|
| 109 | * proper random API (Gskit, PolarSSL or mbedTLS), this function will use
|
---|
| 110 | * "weak" random.
|
---|
| 111 | *
|
---|
| 112 | * When built *with* TLS support and a backend that offers strong random, it
|
---|
| 113 | * will return error if it cannot provide strong random values.
|
---|
| 114 | *
|
---|
| 115 | * NOTE: 'data' may be passed in as NULL when coming from external API without
|
---|
| 116 | * easy handle!
|
---|
| 117 | *
|
---|
| 118 | */
|
---|
| 119 |
|
---|
| 120 | CURLcode Curl_rand(struct Curl_easy *data, unsigned char *rnd, size_t num)
|
---|
| 121 | {
|
---|
| 122 | CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT;
|
---|
| 123 |
|
---|
| 124 | DEBUGASSERT(num > 0);
|
---|
| 125 |
|
---|
| 126 | while(num) {
|
---|
| 127 | unsigned int r;
|
---|
| 128 | size_t left = num < sizeof(unsigned int) ? num : sizeof(unsigned int);
|
---|
| 129 |
|
---|
| 130 | result = randit(data, &r);
|
---|
| 131 | if(result)
|
---|
| 132 | return result;
|
---|
| 133 |
|
---|
| 134 | while(left) {
|
---|
| 135 | *rnd++ = (unsigned char)(r & 0xFF);
|
---|
| 136 | r >>= 8;
|
---|
| 137 | --num;
|
---|
| 138 | --left;
|
---|
| 139 | }
|
---|
| 140 | }
|
---|
| 141 |
|
---|
| 142 | return result;
|
---|
| 143 | }
|
---|
| 144 |
|
---|
| 145 | /*
|
---|
| 146 | * Curl_rand_hex() fills the 'rnd' buffer with a given 'num' size with random
|
---|
| 147 | * hexadecimal digits PLUS a zero terminating byte. It must be an odd number
|
---|
| 148 | * size.
|
---|
| 149 | */
|
---|
| 150 |
|
---|
| 151 | CURLcode Curl_rand_hex(struct Curl_easy *data, unsigned char *rnd,
|
---|
| 152 | size_t num)
|
---|
| 153 | {
|
---|
| 154 | CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT;
|
---|
| 155 | const char *hex = "0123456789abcdef";
|
---|
| 156 | unsigned char buffer[128];
|
---|
| 157 | unsigned char *bufp = buffer;
|
---|
| 158 | DEBUGASSERT(num > 1);
|
---|
| 159 |
|
---|
| 160 | if((num/2 >= sizeof(buffer)) || !(num&1))
|
---|
| 161 | /* make sure it fits in the local buffer and that it is an odd number! */
|
---|
| 162 | return CURLE_BAD_FUNCTION_ARGUMENT;
|
---|
| 163 |
|
---|
| 164 | num--; /* save one for zero termination */
|
---|
| 165 |
|
---|
| 166 | result = Curl_rand(data, buffer, num/2);
|
---|
| 167 | if(result)
|
---|
| 168 | return result;
|
---|
| 169 |
|
---|
| 170 | while(num) {
|
---|
| 171 | *rnd++ = hex[(*bufp & 0xF0)>>4];
|
---|
| 172 | *rnd++ = hex[*bufp & 0x0F];
|
---|
| 173 | bufp++;
|
---|
| 174 | num -= 2;
|
---|
| 175 | }
|
---|
| 176 | *rnd = 0;
|
---|
| 177 |
|
---|
| 178 | return result;
|
---|
| 179 | }
|
---|