mirror of https://github.com/minetest/minetest.git
1027 lines
27 KiB
C++
1027 lines
27 KiB
C++
/*
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* Secure Remote Password 6a implementation
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* https://github.com/est31/csrp-gmp
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2010, 2013 Tom Cocagne, 2015 est31 <MTest31@outlook.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is furnished to do
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* so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <cstddef>
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#ifdef WIN32
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#include <windows.h>
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#include <wincrypt.h>
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#else
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#include <ctime>
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#endif
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#include <cstdlib>
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#include <cstring>
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#include <cstdio>
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#include <cstdint>
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#include <config.h>
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#if USE_SYSTEM_GMP
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#include <gmp.h>
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#else
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#include <mini-gmp.h>
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#endif
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#include "util/sha256.h"
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#include "srp.h"
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//#define CSRP_USE_SHA1
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#define CSRP_USE_SHA256
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#define CSRP_MAX_HASH (SHA256_DIGEST_LENGTH)
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#define srp_dbg_data(data, datalen, prevtext) ;
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/*void srp_dbg_data(unsigned char * data, size_t datalen, char * prevtext)
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{
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printf(prevtext);
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size_t i;
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for (i = 0; i < datalen; i++)
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{
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printf("%02X", data[i]);
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}
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printf("\n");
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}*/
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static int g_initialized = 0;
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#define RAND_BUFF_MAX 128
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static unsigned int g_rand_idx;
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static unsigned char g_rand_buff[RAND_BUFF_MAX];
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void *(*srp_alloc)(size_t) = &malloc;
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void *(*srp_realloc)(void *, size_t) = &realloc;
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void (*srp_free)(void *) = &free;
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void srp_set_memory_functions(
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void *(*new_srp_alloc)(size_t),
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void *(*new_srp_realloc)(void *, size_t),
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void (*new_srp_free)(void *))
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{
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srp_alloc = new_srp_alloc;
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srp_realloc = new_srp_realloc;
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srp_free = new_srp_free;
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}
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typedef struct {
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mpz_t N;
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mpz_t g;
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} NGConstant;
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struct NGHex {
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const char *n_hex;
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const char *g_hex;
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};
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/* All constants here were pulled from Appendix A of RFC 5054 */
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static struct NGHex global_Ng_constants[] = {
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{/* 1024 */
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"EEAF0AB9ADB38DD69C33F80AFA8FC5E86072618775FF3C0B9EA2314C"
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"9C256576D674DF7496EA81D3383B4813D692C6E0E0D5D8E250B98BE4"
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"8E495C1D6089DAD15DC7D7B46154D6B6CE8EF4AD69B15D4982559B29"
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"7BCF1885C529F566660E57EC68EDBC3C05726CC02FD4CBF4976EAA9A"
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"FD5138FE8376435B9FC61D2FC0EB06E3",
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"2"},
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{/* 2048 */
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"AC6BDB41324A9A9BF166DE5E1389582FAF72B6651987EE07FC319294"
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"3DB56050A37329CBB4A099ED8193E0757767A13DD52312AB4B03310D"
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"CD7F48A9DA04FD50E8083969EDB767B0CF6095179A163AB3661A05FB"
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"D5FAAAE82918A9962F0B93B855F97993EC975EEAA80D740ADBF4FF74"
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"7359D041D5C33EA71D281E446B14773BCA97B43A23FB801676BD207A"
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"436C6481F1D2B9078717461A5B9D32E688F87748544523B524B0D57D"
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"5EA77A2775D2ECFA032CFBDBF52FB3786160279004E57AE6AF874E73"
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"03CE53299CCC041C7BC308D82A5698F3A8D0C38271AE35F8E9DBFBB6"
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"94B5C803D89F7AE435DE236D525F54759B65E372FCD68EF20FA7111F"
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"9E4AFF73",
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"2"},
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{/* 4096 */
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08"
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"8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B"
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"302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9"
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"A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6"
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"49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8"
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"FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D"
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"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C"
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"180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718"
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"3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D"
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"04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D"
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"B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226"
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"1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
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"BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC"
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"E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26"
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"99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB"
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"04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2"
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"233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127"
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"D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934063199"
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"FFFFFFFFFFFFFFFF",
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"5"},
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{/* 8192 */
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"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08"
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"8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B"
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"302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9"
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"A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6"
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"49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8"
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"FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D"
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"670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C"
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"180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718"
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"3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D"
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"04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D"
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"B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226"
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"1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
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"BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC"
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"E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26"
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"99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB"
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"04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2"
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"233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127"
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"D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934028492"
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"36C3FAB4D27C7026C1D4DCB2602646DEC9751E763DBA37BDF8FF9406"
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"AD9E530EE5DB382F413001AEB06A53ED9027D831179727B0865A8918"
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"DA3EDBEBCF9B14ED44CE6CBACED4BB1BDB7F1447E6CC254B33205151"
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"2BD7AF426FB8F401378CD2BF5983CA01C64B92ECF032EA15D1721D03"
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"F482D7CE6E74FEF6D55E702F46980C82B5A84031900B1C9E59E7C97F"
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"BEC7E8F323A97A7E36CC88BE0F1D45B7FF585AC54BD407B22B4154AA"
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"CC8F6D7EBF48E1D814CC5ED20F8037E0A79715EEF29BE32806A1D58B"
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"B7C5DA76F550AA3D8A1FBFF0EB19CCB1A313D55CDA56C9EC2EF29632"
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"387FE8D76E3C0468043E8F663F4860EE12BF2D5B0B7474D6E694F91E"
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"6DBE115974A3926F12FEE5E438777CB6A932DF8CD8BEC4D073B931BA"
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"3BC832B68D9DD300741FA7BF8AFC47ED2576F6936BA424663AAB639C"
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"5AE4F5683423B4742BF1C978238F16CBE39D652DE3FDB8BEFC848AD9"
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"22222E04A4037C0713EB57A81A23F0C73473FC646CEA306B4BCBC886"
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"2F8385DDFA9D4B7FA2C087E879683303ED5BDD3A062B3CF5B3A278A6"
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"6D2A13F83F44F82DDF310EE074AB6A364597E899A0255DC164F31CC5"
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"0846851DF9AB48195DED7EA1B1D510BD7EE74D73FAF36BC31ECFA268"
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"359046F4EB879F924009438B481C6CD7889A002ED5EE382BC9190DA6"
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"FC026E479558E4475677E9AA9E3050E2765694DFC81F56E880B96E71"
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"60C980DD98EDD3DFFFFFFFFFFFFFFFFF",
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"13"},
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{0, 0} /* null sentinel */
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};
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static void delete_ng(NGConstant *ng)
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{
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if (ng) {
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mpz_clear(ng->N);
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mpz_clear(ng->g);
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srp_free(ng);
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}
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}
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static NGConstant *new_ng(SRP_NGType ng_type, const char *n_hex, const char *g_hex)
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{
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NGConstant *ng = (NGConstant *)srp_alloc(sizeof(NGConstant));
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if (!ng) return 0;
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mpz_init(ng->N);
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mpz_init(ng->g);
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if (ng_type != SRP_NG_CUSTOM) {
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n_hex = global_Ng_constants[ng_type].n_hex;
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g_hex = global_Ng_constants[ng_type].g_hex;
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}
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int rv = 0;
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rv = mpz_set_str(ng->N, n_hex, 16);
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rv = rv | mpz_set_str(ng->g, g_hex, 16);
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if (rv) {
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delete_ng(ng);
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return 0;
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}
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return ng;
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}
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typedef union {
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// SHA_CTX sha;
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SHA256_CTX sha256;
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// SHA512_CTX sha512;
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} HashCTX;
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struct SRPVerifier {
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SRP_HashAlgorithm hash_alg;
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NGConstant *ng;
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char *username;
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unsigned char *bytes_B;
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int authenticated;
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unsigned char M[CSRP_MAX_HASH];
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unsigned char H_AMK[CSRP_MAX_HASH];
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unsigned char session_key[CSRP_MAX_HASH];
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};
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struct SRPUser {
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SRP_HashAlgorithm hash_alg;
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NGConstant *ng;
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mpz_t a;
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mpz_t A;
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mpz_t S;
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unsigned char *bytes_A;
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int authenticated;
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char *username;
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char *username_verifier;
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unsigned char *password;
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size_t password_len;
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unsigned char M[CSRP_MAX_HASH];
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unsigned char H_AMK[CSRP_MAX_HASH];
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unsigned char session_key[CSRP_MAX_HASH];
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};
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static int hash_init(SRP_HashAlgorithm alg, HashCTX *c)
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{
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switch (alg) {
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#ifdef CSRP_USE_SHA1
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case SRP_SHA1: return SHA1_Init(&c->sha);
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#endif
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/*
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case SRP_SHA224: return SHA224_Init(&c->sha256);
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*/
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#ifdef CSRP_USE_SHA256
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case SRP_SHA256: return SHA256_Init(&c->sha256);
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#endif
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/*
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case SRP_SHA384: return SHA384_Init(&c->sha512);
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case SRP_SHA512: return SHA512_Init(&c->sha512);
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*/
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default: return -1;
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};
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}
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static int hash_update( SRP_HashAlgorithm alg, HashCTX *c, const void *data, size_t len )
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{
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switch (alg) {
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#ifdef CSRP_USE_SHA1
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case SRP_SHA1: return SHA1_Update(&c->sha, data, len);
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#endif
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/*
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case SRP_SHA224: return SHA224_Update(&c->sha256, data, len);
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*/
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#ifdef CSRP_USE_SHA256
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case SRP_SHA256: return SHA256_Update(&c->sha256, data, len);
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#endif
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/*
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case SRP_SHA384: return SHA384_Update(&c->sha512, data, len);
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case SRP_SHA512: return SHA512_Update(&c->sha512, data, len);
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*/
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default: return -1;
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};
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}
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static int hash_final( SRP_HashAlgorithm alg, HashCTX *c, unsigned char *md )
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{
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switch (alg) {
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#ifdef CSRP_USE_SHA1
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case SRP_SHA1: return SHA1_Final(md, &c->sha);
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#endif
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/*
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case SRP_SHA224: return SHA224_Final(md, &c->sha256);
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*/
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#ifdef CSRP_USE_SHA256
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case SRP_SHA256: return SHA256_Final(md, &c->sha256);
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#endif
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/*
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case SRP_SHA384: return SHA384_Final(md, &c->sha512);
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case SRP_SHA512: return SHA512_Final(md, &c->sha512);
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*/
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default: return -1;
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};
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}
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static unsigned char *hash(SRP_HashAlgorithm alg, const unsigned char *d, size_t n, unsigned char *md)
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{
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switch (alg) {
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#ifdef CSRP_USE_SHA1
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case SRP_SHA1: return SHA1(d, n, md);
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#endif
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/*
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case SRP_SHA224: return SHA224( d, n, md );
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*/
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#ifdef CSRP_USE_SHA256
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case SRP_SHA256: return SHA256(d, n, md);
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#endif
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/*
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case SRP_SHA384: return SHA384( d, n, md );
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case SRP_SHA512: return SHA512( d, n, md );
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*/
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default: return 0;
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};
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}
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static size_t hash_length(SRP_HashAlgorithm alg)
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{
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switch (alg) {
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#ifdef CSRP_USE_SHA1
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case SRP_SHA1: return SHA_DIGEST_LENGTH;
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#endif
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/*
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case SRP_SHA224: return SHA224_DIGEST_LENGTH;
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*/
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#ifdef CSRP_USE_SHA256
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case SRP_SHA256: return SHA256_DIGEST_LENGTH;
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#endif
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/*
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case SRP_SHA384: return SHA384_DIGEST_LENGTH;
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case SRP_SHA512: return SHA512_DIGEST_LENGTH;
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*/
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default: return 0;
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};
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}
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inline static int mpz_num_bytes(const mpz_t op)
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{
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return (mpz_sizeinbase(op, 2) + 7) / 8;
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}
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inline static void mpz_to_bin(const mpz_t op, unsigned char *to)
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{
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mpz_export(to, NULL, 1, 1, 1, 0, op);
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}
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|
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inline static void mpz_from_bin(const unsigned char *s, size_t len, mpz_t ret)
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{
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mpz_import(ret, len, 1, 1, 1, 0, s);
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}
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|
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// set op to (op1 * op2) mod d, using tmp for the calculation
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inline static void mpz_mulm(
|
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mpz_t op, const mpz_t op1, const mpz_t op2, const mpz_t d, mpz_t tmp)
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{
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mpz_mul(tmp, op1, op2);
|
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mpz_mod(op, tmp, d);
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}
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|
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// set op to (op1 + op2) mod d, using tmp for the calculation
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inline static void mpz_addm(
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mpz_t op, const mpz_t op1, const mpz_t op2, const mpz_t d, mpz_t tmp)
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{
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mpz_add(tmp, op1, op2);
|
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mpz_mod(op, tmp, d);
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}
|
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|
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// set op to (op1 - op2) mod d, using tmp for the calculation
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inline static void mpz_subm(
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mpz_t op, const mpz_t op1, const mpz_t op2, const mpz_t d, mpz_t tmp)
|
|
{
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mpz_sub(tmp, op1, op2);
|
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mpz_mod(op, tmp, d);
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}
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|
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static SRP_Result H_nn(
|
|
mpz_t result, SRP_HashAlgorithm alg, const mpz_t N, const mpz_t n1, const mpz_t n2)
|
|
{
|
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unsigned char buff[CSRP_MAX_HASH];
|
|
size_t len_N = mpz_num_bytes(N);
|
|
size_t len_n1 = mpz_num_bytes(n1);
|
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size_t len_n2 = mpz_num_bytes(n2);
|
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size_t nbytes = len_N + len_N;
|
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unsigned char *bin = (unsigned char *)srp_alloc(nbytes);
|
|
if (!bin) return SRP_ERR;
|
|
if (len_n1 > len_N || len_n2 > len_N) {
|
|
srp_free(bin);
|
|
return SRP_ERR;
|
|
}
|
|
memset(bin, 0, nbytes);
|
|
mpz_to_bin(n1, bin + (len_N - len_n1));
|
|
mpz_to_bin(n2, bin + (len_N + len_N - len_n2));
|
|
hash(alg, bin, nbytes, buff);
|
|
srp_free(bin);
|
|
mpz_from_bin(buff, hash_length(alg), result);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result H_ns(mpz_t result, SRP_HashAlgorithm alg, const unsigned char *n,
|
|
size_t len_n, const unsigned char *bytes, size_t len_bytes)
|
|
{
|
|
unsigned char buff[CSRP_MAX_HASH];
|
|
size_t nbytes = len_n + len_bytes;
|
|
unsigned char *bin = (unsigned char *)srp_alloc(nbytes);
|
|
if (!bin) return SRP_ERR;
|
|
memcpy(bin, n, len_n);
|
|
memcpy(bin + len_n, bytes, len_bytes);
|
|
hash(alg, bin, nbytes, buff);
|
|
srp_free(bin);
|
|
mpz_from_bin(buff, hash_length(alg), result);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static int calculate_x(mpz_t result, SRP_HashAlgorithm alg, const unsigned char *salt,
|
|
size_t salt_len, const char *username, const unsigned char *password,
|
|
size_t password_len)
|
|
{
|
|
unsigned char ucp_hash[CSRP_MAX_HASH];
|
|
HashCTX ctx;
|
|
hash_init(alg, &ctx);
|
|
|
|
srp_dbg_data((char *)username, strlen(username), "Username for x: ");
|
|
srp_dbg_data((char *)password, password_len, "Password for x: ");
|
|
hash_update(alg, &ctx, username, strlen(username));
|
|
hash_update(alg, &ctx, ":", 1);
|
|
hash_update(alg, &ctx, password, password_len);
|
|
|
|
hash_final(alg, &ctx, ucp_hash);
|
|
|
|
return H_ns(result, alg, salt, salt_len, ucp_hash, hash_length(alg));
|
|
}
|
|
|
|
static SRP_Result update_hash_n(SRP_HashAlgorithm alg, HashCTX *ctx, const mpz_t n)
|
|
{
|
|
size_t len = mpz_num_bytes(n);
|
|
unsigned char *n_bytes = (unsigned char *)srp_alloc(len);
|
|
if (!n_bytes) return SRP_ERR;
|
|
mpz_to_bin(n, n_bytes);
|
|
hash_update(alg, ctx, n_bytes, len);
|
|
srp_free(n_bytes);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result hash_num(SRP_HashAlgorithm alg, const mpz_t n, unsigned char *dest)
|
|
{
|
|
int nbytes = mpz_num_bytes(n);
|
|
unsigned char *bin = (unsigned char *)srp_alloc(nbytes);
|
|
if (!bin) return SRP_ERR;
|
|
mpz_to_bin(n, bin);
|
|
hash(alg, bin, nbytes, dest);
|
|
srp_free(bin);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result calculate_M(SRP_HashAlgorithm alg, NGConstant *ng, unsigned char *dest,
|
|
const char *I, const unsigned char *s_bytes, size_t s_len, const mpz_t A,
|
|
const mpz_t B, const unsigned char *K)
|
|
{
|
|
unsigned char H_N[CSRP_MAX_HASH];
|
|
unsigned char H_g[CSRP_MAX_HASH];
|
|
unsigned char H_I[CSRP_MAX_HASH];
|
|
unsigned char H_xor[CSRP_MAX_HASH];
|
|
HashCTX ctx;
|
|
size_t i = 0;
|
|
size_t hash_len = hash_length(alg);
|
|
|
|
if (!hash_num(alg, ng->N, H_N)) return SRP_ERR;
|
|
if (!hash_num(alg, ng->g, H_g)) return SRP_ERR;
|
|
|
|
hash(alg, (const unsigned char *)I, strlen(I), H_I);
|
|
|
|
for (i = 0; i < hash_len; i++)
|
|
H_xor[i] = H_N[i] ^ H_g[i];
|
|
|
|
hash_init(alg, &ctx);
|
|
|
|
hash_update(alg, &ctx, H_xor, hash_len);
|
|
hash_update(alg, &ctx, H_I, hash_len);
|
|
hash_update(alg, &ctx, s_bytes, s_len);
|
|
if (!update_hash_n(alg, &ctx, A)) return SRP_ERR;
|
|
if (!update_hash_n(alg, &ctx, B)) return SRP_ERR;
|
|
hash_update(alg, &ctx, K, hash_len);
|
|
|
|
hash_final(alg, &ctx, dest);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result calculate_H_AMK(SRP_HashAlgorithm alg, unsigned char *dest,
|
|
const mpz_t A, const unsigned char *M, const unsigned char *K)
|
|
{
|
|
HashCTX ctx;
|
|
|
|
hash_init(alg, &ctx);
|
|
|
|
if (!update_hash_n(alg, &ctx, A)) return SRP_ERR;
|
|
hash_update(alg, &ctx, M, hash_length(alg));
|
|
hash_update(alg, &ctx, K, hash_length(alg));
|
|
|
|
hash_final(alg, &ctx, dest);
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result fill_buff()
|
|
{
|
|
g_rand_idx = 0;
|
|
|
|
#ifdef WIN32
|
|
HCRYPTPROV wctx;
|
|
#else
|
|
FILE *fp = 0;
|
|
#endif
|
|
|
|
#ifdef WIN32
|
|
|
|
if (!CryptAcquireContext(&wctx, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
|
|
return SRP_ERR;
|
|
if (!CryptGenRandom(wctx, sizeof(g_rand_buff), (BYTE *)g_rand_buff)) return SRP_ERR;
|
|
if (!CryptReleaseContext(wctx, 0)) return SRP_ERR;
|
|
|
|
#else
|
|
fp = fopen("/dev/urandom", "r");
|
|
|
|
if (!fp) return SRP_ERR;
|
|
|
|
if (fread(g_rand_buff, sizeof(g_rand_buff), 1, fp) != 1) { fclose(fp); return SRP_ERR; }
|
|
if (fclose(fp)) return SRP_ERR;
|
|
#endif
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result mpz_fill_random(mpz_t num)
|
|
{
|
|
// was call: BN_rand(num, 256, -1, 0);
|
|
if (RAND_BUFF_MAX - g_rand_idx < 32)
|
|
if (fill_buff() != SRP_OK) return SRP_ERR;
|
|
mpz_from_bin((const unsigned char *)(&g_rand_buff[g_rand_idx]), 32, num);
|
|
g_rand_idx += 32;
|
|
return SRP_OK;
|
|
}
|
|
|
|
static SRP_Result init_random()
|
|
{
|
|
if (g_initialized) return SRP_OK;
|
|
SRP_Result ret = fill_buff();
|
|
g_initialized = (ret == SRP_OK);
|
|
return ret;
|
|
}
|
|
|
|
#define srp_dbg_num(num, text) ;
|
|
/*void srp_dbg_num(mpz_t num, char * prevtext)
|
|
{
|
|
int len_num = mpz_num_bytes(num);
|
|
char *bytes_num = (char*) srp_alloc(len_num);
|
|
mpz_to_bin(num, (unsigned char *) bytes_num);
|
|
srp_dbg_data(bytes_num, len_num, prevtext);
|
|
srp_free(bytes_num);
|
|
|
|
}*/
|
|
|
|
/***********************************************************************************************************
|
|
*
|
|
* Exported Functions
|
|
*
|
|
***********************************************************************************************************/
|
|
|
|
SRP_Result srp_create_salted_verification_key( SRP_HashAlgorithm alg,
|
|
SRP_NGType ng_type, const char *username_for_verifier,
|
|
const unsigned char *password, size_t len_password,
|
|
unsigned char **bytes_s, size_t *len_s,
|
|
unsigned char **bytes_v, size_t *len_v,
|
|
const char *n_hex, const char *g_hex )
|
|
{
|
|
SRP_Result ret = SRP_OK;
|
|
|
|
mpz_t v; mpz_init(v);
|
|
mpz_t x; mpz_init(x);
|
|
|
|
NGConstant *ng = new_ng(ng_type, n_hex, g_hex);
|
|
|
|
if (!ng) goto error_and_exit;
|
|
|
|
if (init_random() != SRP_OK) /* Only happens once */
|
|
goto error_and_exit;
|
|
|
|
if (*bytes_s == NULL) {
|
|
size_t size_to_fill = 16;
|
|
*len_s = size_to_fill;
|
|
if (RAND_BUFF_MAX - g_rand_idx < size_to_fill)
|
|
if (fill_buff() != SRP_OK) goto error_and_exit;
|
|
*bytes_s = (unsigned char *)srp_alloc(size_to_fill);
|
|
if (!*bytes_s) goto error_and_exit;
|
|
memcpy(*bytes_s, &g_rand_buff[g_rand_idx], size_to_fill);
|
|
g_rand_idx += size_to_fill;
|
|
}
|
|
|
|
if (!calculate_x(
|
|
x, alg, *bytes_s, *len_s, username_for_verifier, password, len_password))
|
|
goto error_and_exit;
|
|
|
|
srp_dbg_num(x, "Server calculated x: ");
|
|
|
|
mpz_powm(v, ng->g, x, ng->N);
|
|
|
|
*len_v = mpz_num_bytes(v);
|
|
|
|
*bytes_v = (unsigned char *)srp_alloc(*len_v);
|
|
|
|
if (!*bytes_v) goto error_and_exit;
|
|
|
|
mpz_to_bin(v, *bytes_v);
|
|
|
|
cleanup_and_exit:
|
|
delete_ng(ng);
|
|
mpz_clear(v);
|
|
mpz_clear(x);
|
|
return ret;
|
|
error_and_exit:
|
|
ret = SRP_ERR;
|
|
goto cleanup_and_exit;
|
|
}
|
|
|
|
|
|
/* Out: bytes_B, len_B.
|
|
*
|
|
* On failure, bytes_B will be set to NULL and len_B will be set to 0
|
|
*/
|
|
struct SRPVerifier *srp_verifier_new(SRP_HashAlgorithm alg,
|
|
SRP_NGType ng_type, const char *username,
|
|
const unsigned char *bytes_s, size_t len_s,
|
|
const unsigned char *bytes_v, size_t len_v,
|
|
const unsigned char *bytes_A, size_t len_A,
|
|
const unsigned char *bytes_b, size_t len_b,
|
|
unsigned char **bytes_B, size_t *len_B,
|
|
const char *n_hex, const char *g_hex )
|
|
{
|
|
mpz_t v; mpz_init(v); mpz_from_bin(bytes_v, len_v, v);
|
|
mpz_t A; mpz_init(A); mpz_from_bin(bytes_A, len_A, A);
|
|
mpz_t u; mpz_init(u);
|
|
mpz_t B; mpz_init(B);
|
|
mpz_t S; mpz_init(S);
|
|
mpz_t b; mpz_init(b);
|
|
mpz_t k; mpz_init(k);
|
|
mpz_t tmp1; mpz_init(tmp1);
|
|
mpz_t tmp2; mpz_init(tmp2);
|
|
mpz_t tmp3; mpz_init(tmp3);
|
|
size_t ulen = strlen(username) + 1;
|
|
NGConstant *ng = new_ng(ng_type, n_hex, g_hex);
|
|
struct SRPVerifier *ver = 0;
|
|
|
|
*len_B = 0;
|
|
*bytes_B = 0;
|
|
|
|
if (!ng) goto cleanup_and_exit;
|
|
|
|
ver = (struct SRPVerifier *)srp_alloc(sizeof(struct SRPVerifier));
|
|
|
|
if (!ver) goto cleanup_and_exit;
|
|
|
|
if (init_random() != SRP_OK) { /* Only happens once */
|
|
srp_free(ver);
|
|
ver = 0;
|
|
goto cleanup_and_exit;
|
|
}
|
|
|
|
ver->username = (char *)srp_alloc(ulen);
|
|
ver->hash_alg = alg;
|
|
ver->ng = ng;
|
|
|
|
if (!ver->username) {
|
|
srp_free(ver);
|
|
ver = 0;
|
|
goto cleanup_and_exit;
|
|
}
|
|
|
|
memcpy(ver->username, username, ulen);
|
|
|
|
ver->authenticated = 0;
|
|
|
|
/* SRP-6a safety check */
|
|
mpz_mod(tmp1, A, ng->N);
|
|
if (mpz_sgn(tmp1) != 0) {
|
|
if (bytes_b) {
|
|
mpz_from_bin(bytes_b, len_b, b);
|
|
} else {
|
|
if (!mpz_fill_random(b)) goto ver_cleanup_and_exit;
|
|
}
|
|
|
|
if (!H_nn(k, alg, ng->N, ng->N, ng->g)) goto ver_cleanup_and_exit;
|
|
|
|
/* B = kv + g^b */
|
|
mpz_mulm(tmp1, k, v, ng->N, tmp3);
|
|
mpz_powm(tmp2, ng->g, b, ng->N);
|
|
mpz_addm(B, tmp1, tmp2, ng->N, tmp3);
|
|
|
|
if (!H_nn(u, alg, ng->N, A, B)) goto ver_cleanup_and_exit;
|
|
|
|
srp_dbg_num(u, "Server calculated u: ");
|
|
|
|
/* S = (A *(v^u)) ^ b */
|
|
mpz_powm(tmp1, v, u, ng->N);
|
|
mpz_mulm(tmp2, A, tmp1, ng->N, tmp3);
|
|
mpz_powm(S, tmp2, b, ng->N);
|
|
|
|
if (!hash_num(alg, S, ver->session_key)) goto ver_cleanup_and_exit;
|
|
|
|
if (!calculate_M(
|
|
alg, ng, ver->M, username, bytes_s, len_s, A, B, ver->session_key)) {
|
|
goto ver_cleanup_and_exit;
|
|
}
|
|
if (!calculate_H_AMK(alg, ver->H_AMK, A, ver->M, ver->session_key)) {
|
|
goto ver_cleanup_and_exit;
|
|
}
|
|
|
|
*len_B = mpz_num_bytes(B);
|
|
*bytes_B = (unsigned char *)srp_alloc(*len_B);
|
|
|
|
if (!*bytes_B) {
|
|
*len_B = 0;
|
|
goto ver_cleanup_and_exit;
|
|
}
|
|
|
|
mpz_to_bin(B, *bytes_B);
|
|
|
|
ver->bytes_B = *bytes_B;
|
|
} else {
|
|
srp_free(ver);
|
|
ver = 0;
|
|
}
|
|
|
|
cleanup_and_exit:
|
|
mpz_clear(v);
|
|
mpz_clear(A);
|
|
mpz_clear(u);
|
|
mpz_clear(k);
|
|
mpz_clear(B);
|
|
mpz_clear(S);
|
|
mpz_clear(b);
|
|
mpz_clear(tmp1);
|
|
mpz_clear(tmp2);
|
|
mpz_clear(tmp3);
|
|
return ver;
|
|
ver_cleanup_and_exit:
|
|
srp_free(ver->username);
|
|
srp_free(ver);
|
|
ver = 0;
|
|
goto cleanup_and_exit;
|
|
}
|
|
|
|
void srp_verifier_delete(struct SRPVerifier *ver)
|
|
{
|
|
if (ver) {
|
|
delete_ng(ver->ng);
|
|
srp_free(ver->username);
|
|
srp_free(ver->bytes_B);
|
|
memset(ver, 0, sizeof(*ver));
|
|
srp_free(ver);
|
|
}
|
|
}
|
|
|
|
int srp_verifier_is_authenticated(struct SRPVerifier *ver)
|
|
{
|
|
return ver->authenticated;
|
|
}
|
|
|
|
const char *srp_verifier_get_username(struct SRPVerifier *ver)
|
|
{
|
|
return ver->username;
|
|
}
|
|
|
|
const unsigned char *srp_verifier_get_session_key(
|
|
struct SRPVerifier *ver, size_t *key_length)
|
|
{
|
|
if (key_length) *key_length = hash_length(ver->hash_alg);
|
|
return ver->session_key;
|
|
}
|
|
|
|
size_t srp_verifier_get_session_key_length(struct SRPVerifier *ver)
|
|
{
|
|
return hash_length(ver->hash_alg);
|
|
}
|
|
|
|
/* user_M must be exactly CSRP_MAX_HASH bytes in size */
|
|
void srp_verifier_verify_session(
|
|
struct SRPVerifier *ver, const unsigned char *user_M, unsigned char **bytes_HAMK)
|
|
{
|
|
if (memcmp(ver->M, user_M, hash_length(ver->hash_alg)) == 0) {
|
|
ver->authenticated = 1;
|
|
*bytes_HAMK = ver->H_AMK;
|
|
} else
|
|
*bytes_HAMK = NULL;
|
|
}
|
|
|
|
/*******************************************************************************/
|
|
|
|
struct SRPUser *srp_user_new(SRP_HashAlgorithm alg, SRP_NGType ng_type,
|
|
const char *username, const char *username_for_verifier,
|
|
const unsigned char *bytes_password, size_t len_password, const char *n_hex,
|
|
const char *g_hex)
|
|
{
|
|
struct SRPUser *usr = (struct SRPUser *)srp_alloc(sizeof(struct SRPUser));
|
|
size_t ulen = strlen(username) + 1;
|
|
size_t uvlen = strlen(username_for_verifier) + 1;
|
|
|
|
if (!usr) goto err_exit;
|
|
|
|
if (init_random() != SRP_OK) /* Only happens once */
|
|
goto err_exit;
|
|
|
|
usr->hash_alg = alg;
|
|
usr->ng = new_ng(ng_type, n_hex, g_hex);
|
|
|
|
mpz_init(usr->a);
|
|
mpz_init(usr->A);
|
|
mpz_init(usr->S);
|
|
|
|
if (!usr->ng) goto err_exit;
|
|
|
|
usr->username = (char *)srp_alloc(ulen);
|
|
usr->username_verifier = (char *)srp_alloc(uvlen);
|
|
usr->password = (unsigned char *)srp_alloc(len_password);
|
|
usr->password_len = len_password;
|
|
|
|
if (!usr->username || !usr->password || !usr->username_verifier) goto err_exit;
|
|
|
|
memcpy(usr->username, username, ulen);
|
|
memcpy(usr->username_verifier, username_for_verifier, uvlen);
|
|
memcpy(usr->password, bytes_password, len_password);
|
|
|
|
usr->authenticated = 0;
|
|
|
|
usr->bytes_A = 0;
|
|
|
|
return usr;
|
|
|
|
err_exit:
|
|
if (usr) {
|
|
mpz_clear(usr->a);
|
|
mpz_clear(usr->A);
|
|
mpz_clear(usr->S);
|
|
delete_ng(usr->ng);
|
|
srp_free(usr->username);
|
|
srp_free(usr->username_verifier);
|
|
if (usr->password) {
|
|
memset(usr->password, 0, usr->password_len);
|
|
srp_free(usr->password);
|
|
}
|
|
srp_free(usr);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void srp_user_delete(struct SRPUser *usr)
|
|
{
|
|
if (usr) {
|
|
mpz_clear(usr->a);
|
|
mpz_clear(usr->A);
|
|
mpz_clear(usr->S);
|
|
|
|
delete_ng(usr->ng);
|
|
|
|
memset(usr->password, 0, usr->password_len);
|
|
|
|
srp_free(usr->username);
|
|
srp_free(usr->username_verifier);
|
|
srp_free(usr->password);
|
|
|
|
if (usr->bytes_A) srp_free(usr->bytes_A);
|
|
|
|
memset(usr, 0, sizeof(*usr));
|
|
srp_free(usr);
|
|
}
|
|
}
|
|
|
|
int srp_user_is_authenticated(struct SRPUser *usr)
|
|
{
|
|
return usr->authenticated;
|
|
}
|
|
|
|
const char *srp_user_get_username(struct SRPUser *usr)
|
|
{
|
|
return usr->username;
|
|
}
|
|
|
|
const unsigned char *srp_user_get_session_key(struct SRPUser *usr, size_t *key_length)
|
|
{
|
|
if (key_length) *key_length = hash_length(usr->hash_alg);
|
|
return usr->session_key;
|
|
}
|
|
|
|
size_t srp_user_get_session_key_length(struct SRPUser *usr)
|
|
{
|
|
return hash_length(usr->hash_alg);
|
|
}
|
|
|
|
/* Output: username, bytes_A, len_A */
|
|
SRP_Result srp_user_start_authentication(struct SRPUser *usr, char **username,
|
|
const unsigned char *bytes_a, size_t len_a,
|
|
unsigned char **bytes_A, size_t *len_A)
|
|
{
|
|
if (bytes_a) {
|
|
mpz_from_bin(bytes_a, len_a, usr->a);
|
|
} else {
|
|
if (!mpz_fill_random(usr->a)) goto error_and_exit;
|
|
}
|
|
|
|
mpz_powm(usr->A, usr->ng->g, usr->a, usr->ng->N);
|
|
|
|
*len_A = mpz_num_bytes(usr->A);
|
|
*bytes_A = (unsigned char *)srp_alloc(*len_A);
|
|
|
|
if (!*bytes_A) goto error_and_exit;
|
|
|
|
mpz_to_bin(usr->A, *bytes_A);
|
|
|
|
usr->bytes_A = *bytes_A;
|
|
if (username) *username = usr->username;
|
|
|
|
return SRP_OK;
|
|
|
|
error_and_exit:
|
|
*len_A = 0;
|
|
*bytes_A = 0;
|
|
*username = 0;
|
|
return SRP_ERR;
|
|
}
|
|
|
|
/* Output: bytes_M. Buffer length is CSRP_MAX_HASH */
|
|
void srp_user_process_challenge(struct SRPUser *usr,
|
|
const unsigned char *bytes_s, size_t len_s,
|
|
const unsigned char *bytes_B, size_t len_B,
|
|
unsigned char **bytes_M, size_t *len_M)
|
|
{
|
|
mpz_t B; mpz_init(B); mpz_from_bin(bytes_B, len_B, B);
|
|
mpz_t u; mpz_init(u);
|
|
mpz_t x; mpz_init(x);
|
|
mpz_t k; mpz_init(k);
|
|
mpz_t v; mpz_init(v);
|
|
mpz_t tmp1; mpz_init(tmp1);
|
|
mpz_t tmp2; mpz_init(tmp2);
|
|
mpz_t tmp3; mpz_init(tmp3);
|
|
mpz_t tmp4; mpz_init(tmp4);
|
|
|
|
*len_M = 0;
|
|
*bytes_M = 0;
|
|
|
|
if (!H_nn(u, usr->hash_alg, usr->ng->N, usr->A, B)) goto cleanup_and_exit;
|
|
|
|
srp_dbg_num(u, "Client calculated u: ");
|
|
|
|
if (!calculate_x(x, usr->hash_alg, bytes_s, len_s, usr->username_verifier,
|
|
usr->password, usr->password_len))
|
|
goto cleanup_and_exit;
|
|
|
|
srp_dbg_num(x, "Client calculated x: ");
|
|
|
|
if (!H_nn(k, usr->hash_alg, usr->ng->N, usr->ng->N, usr->ng->g))
|
|
goto cleanup_and_exit;
|
|
|
|
/* SRP-6a safety check */
|
|
if (mpz_sgn(B) != 0 && mpz_sgn(u) != 0) {
|
|
mpz_powm(v, usr->ng->g, x, usr->ng->N);
|
|
|
|
srp_dbg_num(v, "Client calculated v: ");
|
|
|
|
/* S = (B - k*(g^x)) ^ (a + ux) */
|
|
mpz_mul(tmp1, u, x);
|
|
mpz_add(tmp2, usr->a, tmp1); /* tmp2 = (a + ux) */
|
|
mpz_powm(tmp1, usr->ng->g, x, usr->ng->N); /* tmp1 = g^x */
|
|
mpz_mulm(tmp3, k, tmp1, usr->ng->N, tmp4); /* tmp3 = k*(g^x) */
|
|
mpz_subm(tmp1, B, tmp3, usr->ng->N, tmp4); /* tmp1 = (B - K*(g^x)) */
|
|
mpz_powm(usr->S, tmp1, tmp2, usr->ng->N);
|
|
|
|
if (!hash_num(usr->hash_alg, usr->S, usr->session_key)) goto cleanup_and_exit;
|
|
|
|
if (!calculate_M(usr->hash_alg, usr->ng, usr->M, usr->username, bytes_s, len_s,
|
|
usr->A, B, usr->session_key))
|
|
goto cleanup_and_exit;
|
|
if (!calculate_H_AMK(usr->hash_alg, usr->H_AMK, usr->A, usr->M, usr->session_key))
|
|
goto cleanup_and_exit;
|
|
|
|
*bytes_M = usr->M;
|
|
*len_M = hash_length(usr->hash_alg);
|
|
} else {
|
|
*bytes_M = NULL;
|
|
*len_M = 0;
|
|
}
|
|
|
|
cleanup_and_exit:
|
|
mpz_clear(B);
|
|
mpz_clear(u);
|
|
mpz_clear(x);
|
|
mpz_clear(k);
|
|
mpz_clear(v);
|
|
mpz_clear(tmp1);
|
|
mpz_clear(tmp2);
|
|
mpz_clear(tmp3);
|
|
mpz_clear(tmp4);
|
|
}
|
|
|
|
void srp_user_verify_session(struct SRPUser *usr, const unsigned char *bytes_HAMK)
|
|
{
|
|
if (memcmp(usr->H_AMK, bytes_HAMK, hash_length(usr->hash_alg)) == 0)
|
|
usr->authenticated = 1;
|
|
}
|