| /* |
| * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the OpenSSL license (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #ifndef OPENSSL_NO_SRP |
| # include "internal/cryptlib.h" |
| # include <openssl/sha.h> |
| # include <openssl/srp.h> |
| # include <openssl/evp.h> |
| # include <openssl/buffer.h> |
| # include <openssl/rand.h> |
| # include <openssl/txt_db.h> |
| |
| # define SRP_RANDOM_SALT_LEN 20 |
| # define MAX_LEN 2500 |
| |
| static char b64table[] = |
| "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./"; |
| |
| /* |
| * the following two conversion routines have been inspired by code from |
| * Stanford |
| */ |
| |
| /* |
| * Convert a base64 string into raw byte array representation. |
| */ |
| static int t_fromb64(unsigned char *a, size_t alen, const char *src) |
| { |
| char *loc; |
| int i, j; |
| int size; |
| |
| while (*src && (*src == ' ' || *src == '\t' || *src == '\n')) |
| ++src; |
| size = strlen(src); |
| if (alen > INT_MAX || size > (int)alen) |
| return -1; |
| |
| i = 0; |
| while (i < size) { |
| loc = strchr(b64table, src[i]); |
| if (loc == (char *)0) |
| break; |
| else |
| a[i] = loc - b64table; |
| ++i; |
| } |
| /* if nothing valid to process we have a zero length response */ |
| if (i == 0) |
| return 0; |
| size = i; |
| i = size - 1; |
| j = size; |
| while (1) { |
| a[j] = a[i]; |
| if (--i < 0) |
| break; |
| a[j] |= (a[i] & 3) << 6; |
| --j; |
| a[j] = (unsigned char)((a[i] & 0x3c) >> 2); |
| if (--i < 0) |
| break; |
| a[j] |= (a[i] & 0xf) << 4; |
| --j; |
| a[j] = (unsigned char)((a[i] & 0x30) >> 4); |
| if (--i < 0) |
| break; |
| a[j] |= (a[i] << 2); |
| |
| a[--j] = 0; |
| if (--i < 0) |
| break; |
| } |
| while (a[j] == 0 && j <= size) |
| ++j; |
| i = 0; |
| while (j <= size) |
| a[i++] = a[j++]; |
| return i; |
| } |
| |
| /* |
| * Convert a raw byte string into a null-terminated base64 ASCII string. |
| */ |
| static char *t_tob64(char *dst, const unsigned char *src, int size) |
| { |
| int c, pos = size % 3; |
| unsigned char b0 = 0, b1 = 0, b2 = 0, notleading = 0; |
| char *olddst = dst; |
| |
| switch (pos) { |
| case 1: |
| b2 = src[0]; |
| break; |
| case 2: |
| b1 = src[0]; |
| b2 = src[1]; |
| break; |
| } |
| |
| while (1) { |
| c = (b0 & 0xfc) >> 2; |
| if (notleading || c != 0) { |
| *dst++ = b64table[c]; |
| notleading = 1; |
| } |
| c = ((b0 & 3) << 4) | ((b1 & 0xf0) >> 4); |
| if (notleading || c != 0) { |
| *dst++ = b64table[c]; |
| notleading = 1; |
| } |
| c = ((b1 & 0xf) << 2) | ((b2 & 0xc0) >> 6); |
| if (notleading || c != 0) { |
| *dst++ = b64table[c]; |
| notleading = 1; |
| } |
| c = b2 & 0x3f; |
| if (notleading || c != 0) { |
| *dst++ = b64table[c]; |
| notleading = 1; |
| } |
| if (pos >= size) |
| break; |
| else { |
| b0 = src[pos++]; |
| b1 = src[pos++]; |
| b2 = src[pos++]; |
| } |
| } |
| |
| *dst++ = '\0'; |
| return olddst; |
| } |
| |
| void SRP_user_pwd_free(SRP_user_pwd *user_pwd) |
| { |
| if (user_pwd == NULL) |
| return; |
| BN_free(user_pwd->s); |
| BN_clear_free(user_pwd->v); |
| OPENSSL_free(user_pwd->id); |
| OPENSSL_free(user_pwd->info); |
| OPENSSL_free(user_pwd); |
| } |
| |
| static SRP_user_pwd *SRP_user_pwd_new(void) |
| { |
| SRP_user_pwd *ret = OPENSSL_malloc(sizeof(*ret)); |
| if (ret == NULL) |
| return NULL; |
| ret->N = NULL; |
| ret->g = NULL; |
| ret->s = NULL; |
| ret->v = NULL; |
| ret->id = NULL; |
| ret->info = NULL; |
| return ret; |
| } |
| |
| static void SRP_user_pwd_set_gN(SRP_user_pwd *vinfo, const BIGNUM *g, |
| const BIGNUM *N) |
| { |
| vinfo->N = N; |
| vinfo->g = g; |
| } |
| |
| static int SRP_user_pwd_set_ids(SRP_user_pwd *vinfo, const char *id, |
| const char *info) |
| { |
| if (id != NULL && NULL == (vinfo->id = OPENSSL_strdup(id))) |
| return 0; |
| return (info == NULL || NULL != (vinfo->info = OPENSSL_strdup(info))); |
| } |
| |
| static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s, |
| const char *v) |
| { |
| unsigned char tmp[MAX_LEN]; |
| int len; |
| |
| vinfo->v = NULL; |
| vinfo->s = NULL; |
| |
| len = t_fromb64(tmp, sizeof(tmp), v); |
| if (len < 0) |
| return 0; |
| if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL))) |
| return 0; |
| len = t_fromb64(tmp, sizeof(tmp), s); |
| if (len < 0) |
| goto err; |
| vinfo->s = BN_bin2bn(tmp, len, NULL); |
| if (vinfo->s == NULL) |
| goto err; |
| return 1; |
| err: |
| BN_free(vinfo->v); |
| vinfo->v = NULL; |
| return 0; |
| } |
| |
| static int SRP_user_pwd_set_sv_BN(SRP_user_pwd *vinfo, BIGNUM *s, BIGNUM *v) |
| { |
| vinfo->v = v; |
| vinfo->s = s; |
| return (vinfo->s != NULL && vinfo->v != NULL); |
| } |
| |
| static SRP_user_pwd *srp_user_pwd_dup(SRP_user_pwd *src) |
| { |
| SRP_user_pwd *ret; |
| |
| if (src == NULL) |
| return NULL; |
| if ((ret = SRP_user_pwd_new()) == NULL) |
| return NULL; |
| |
| SRP_user_pwd_set_gN(ret, src->g, src->N); |
| if (!SRP_user_pwd_set_ids(ret, src->id, src->info) |
| || !SRP_user_pwd_set_sv_BN(ret, BN_dup(src->s), BN_dup(src->v))) { |
| SRP_user_pwd_free(ret); |
| return NULL; |
| } |
| return ret; |
| } |
| |
| SRP_VBASE *SRP_VBASE_new(char *seed_key) |
| { |
| SRP_VBASE *vb = OPENSSL_malloc(sizeof(*vb)); |
| |
| if (vb == NULL) |
| return NULL; |
| if ((vb->users_pwd = sk_SRP_user_pwd_new_null()) == NULL |
| || (vb->gN_cache = sk_SRP_gN_cache_new_null()) == NULL) { |
| OPENSSL_free(vb); |
| return NULL; |
| } |
| vb->default_g = NULL; |
| vb->default_N = NULL; |
| vb->seed_key = NULL; |
| if ((seed_key != NULL) && (vb->seed_key = OPENSSL_strdup(seed_key)) == NULL) { |
| sk_SRP_user_pwd_free(vb->users_pwd); |
| sk_SRP_gN_cache_free(vb->gN_cache); |
| OPENSSL_free(vb); |
| return NULL; |
| } |
| return vb; |
| } |
| |
| void SRP_VBASE_free(SRP_VBASE *vb) |
| { |
| if (!vb) |
| return; |
| sk_SRP_user_pwd_pop_free(vb->users_pwd, SRP_user_pwd_free); |
| sk_SRP_gN_cache_free(vb->gN_cache); |
| OPENSSL_free(vb->seed_key); |
| OPENSSL_free(vb); |
| } |
| |
| static SRP_gN_cache *SRP_gN_new_init(const char *ch) |
| { |
| unsigned char tmp[MAX_LEN]; |
| int len; |
| SRP_gN_cache *newgN = OPENSSL_malloc(sizeof(*newgN)); |
| |
| if (newgN == NULL) |
| return NULL; |
| |
| len = t_fromb64(tmp, sizeof(tmp), ch); |
| if (len < 0) |
| goto err; |
| |
| if ((newgN->b64_bn = OPENSSL_strdup(ch)) == NULL) |
| goto err; |
| |
| if ((newgN->bn = BN_bin2bn(tmp, len, NULL))) |
| return newgN; |
| |
| OPENSSL_free(newgN->b64_bn); |
| err: |
| OPENSSL_free(newgN); |
| return NULL; |
| } |
| |
| static void SRP_gN_free(SRP_gN_cache *gN_cache) |
| { |
| if (gN_cache == NULL) |
| return; |
| OPENSSL_free(gN_cache->b64_bn); |
| BN_free(gN_cache->bn); |
| OPENSSL_free(gN_cache); |
| } |
| |
| static SRP_gN *SRP_get_gN_by_id(const char *id, STACK_OF(SRP_gN) *gN_tab) |
| { |
| int i; |
| |
| SRP_gN *gN; |
| if (gN_tab != NULL) |
| for (i = 0; i < sk_SRP_gN_num(gN_tab); i++) { |
| gN = sk_SRP_gN_value(gN_tab, i); |
| if (gN && (id == NULL || strcmp(gN->id, id) == 0)) |
| return gN; |
| } |
| |
| return SRP_get_default_gN(id); |
| } |
| |
| static BIGNUM *SRP_gN_place_bn(STACK_OF(SRP_gN_cache) *gN_cache, char *ch) |
| { |
| int i; |
| if (gN_cache == NULL) |
| return NULL; |
| |
| /* search if we have already one... */ |
| for (i = 0; i < sk_SRP_gN_cache_num(gN_cache); i++) { |
| SRP_gN_cache *cache = sk_SRP_gN_cache_value(gN_cache, i); |
| if (strcmp(cache->b64_bn, ch) == 0) |
| return cache->bn; |
| } |
| { /* it is the first time that we find it */ |
| SRP_gN_cache *newgN = SRP_gN_new_init(ch); |
| if (newgN) { |
| if (sk_SRP_gN_cache_insert(gN_cache, newgN, 0) > 0) |
| return newgN->bn; |
| SRP_gN_free(newgN); |
| } |
| } |
| return NULL; |
| } |
| |
| /* |
| * this function parses verifier file. Format is: |
| * string(index):base64(N):base64(g):0 |
| * string(username):base64(v):base64(salt):int(index) |
| */ |
| |
| int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file) |
| { |
| int error_code; |
| STACK_OF(SRP_gN) *SRP_gN_tab = sk_SRP_gN_new_null(); |
| char *last_index = NULL; |
| int i; |
| char **pp; |
| |
| SRP_gN *gN = NULL; |
| SRP_user_pwd *user_pwd = NULL; |
| |
| TXT_DB *tmpdb = NULL; |
| BIO *in = BIO_new(BIO_s_file()); |
| |
| error_code = SRP_ERR_OPEN_FILE; |
| |
| if (in == NULL || BIO_read_filename(in, verifier_file) <= 0) |
| goto err; |
| |
| error_code = SRP_ERR_VBASE_INCOMPLETE_FILE; |
| |
| if ((tmpdb = TXT_DB_read(in, DB_NUMBER)) == NULL) |
| goto err; |
| |
| error_code = SRP_ERR_MEMORY; |
| |
| if (vb->seed_key) { |
| last_index = SRP_get_default_gN(NULL)->id; |
| } |
| for (i = 0; i < sk_OPENSSL_PSTRING_num(tmpdb->data); i++) { |
| pp = sk_OPENSSL_PSTRING_value(tmpdb->data, i); |
| if (pp[DB_srptype][0] == DB_SRP_INDEX) { |
| /* |
| * we add this couple in the internal Stack |
| */ |
| |
| if ((gN = OPENSSL_malloc(sizeof(*gN))) == NULL) |
| goto err; |
| |
| if ((gN->id = OPENSSL_strdup(pp[DB_srpid])) == NULL |
| || (gN->N = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpverifier])) |
| == NULL |
| || (gN->g = SRP_gN_place_bn(vb->gN_cache, pp[DB_srpsalt])) |
| == NULL |
| || sk_SRP_gN_insert(SRP_gN_tab, gN, 0) == 0) |
| goto err; |
| |
| gN = NULL; |
| |
| if (vb->seed_key != NULL) { |
| last_index = pp[DB_srpid]; |
| } |
| } else if (pp[DB_srptype][0] == DB_SRP_VALID) { |
| /* it is a user .... */ |
| const SRP_gN *lgN; |
| |
| if ((lgN = SRP_get_gN_by_id(pp[DB_srpgN], SRP_gN_tab)) != NULL) { |
| error_code = SRP_ERR_MEMORY; |
| if ((user_pwd = SRP_user_pwd_new()) == NULL) |
| goto err; |
| |
| SRP_user_pwd_set_gN(user_pwd, lgN->g, lgN->N); |
| if (!SRP_user_pwd_set_ids |
| (user_pwd, pp[DB_srpid], pp[DB_srpinfo])) |
| goto err; |
| |
| error_code = SRP_ERR_VBASE_BN_LIB; |
| if (!SRP_user_pwd_set_sv |
| (user_pwd, pp[DB_srpsalt], pp[DB_srpverifier])) |
| goto err; |
| |
| if (sk_SRP_user_pwd_insert(vb->users_pwd, user_pwd, 0) == 0) |
| goto err; |
| user_pwd = NULL; /* abandon responsibility */ |
| } |
| } |
| } |
| |
| if (last_index != NULL) { |
| /* this means that we want to simulate a default user */ |
| |
| if (((gN = SRP_get_gN_by_id(last_index, SRP_gN_tab)) == NULL)) { |
| error_code = SRP_ERR_VBASE_BN_LIB; |
| goto err; |
| } |
| vb->default_g = gN->g; |
| vb->default_N = gN->N; |
| gN = NULL; |
| } |
| error_code = SRP_NO_ERROR; |
| |
| err: |
| /* |
| * there may be still some leaks to fix, if this fails, the application |
| * terminates most likely |
| */ |
| |
| if (gN != NULL) { |
| OPENSSL_free(gN->id); |
| OPENSSL_free(gN); |
| } |
| |
| SRP_user_pwd_free(user_pwd); |
| |
| TXT_DB_free(tmpdb); |
| BIO_free_all(in); |
| |
| sk_SRP_gN_free(SRP_gN_tab); |
| |
| return error_code; |
| |
| } |
| |
| static SRP_user_pwd *find_user(SRP_VBASE *vb, char *username) |
| { |
| int i; |
| SRP_user_pwd *user; |
| |
| if (vb == NULL) |
| return NULL; |
| |
| for (i = 0; i < sk_SRP_user_pwd_num(vb->users_pwd); i++) { |
| user = sk_SRP_user_pwd_value(vb->users_pwd, i); |
| if (strcmp(user->id, username) == 0) |
| return user; |
| } |
| |
| return NULL; |
| } |
| |
| #if OPENSSL_API_COMPAT < 0x10100000L |
| /* |
| * DEPRECATED: use SRP_VBASE_get1_by_user instead. |
| * This method ignores the configured seed and fails for an unknown user. |
| * Ownership of the returned pointer is not released to the caller. |
| * In other words, caller must not free the result. |
| */ |
| SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username) |
| { |
| return find_user(vb, username); |
| } |
| #endif |
| |
| /* |
| * Ownership of the returned pointer is released to the caller. |
| * In other words, caller must free the result once done. |
| */ |
| SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username) |
| { |
| SRP_user_pwd *user; |
| unsigned char digv[SHA_DIGEST_LENGTH]; |
| unsigned char digs[SHA_DIGEST_LENGTH]; |
| EVP_MD_CTX *ctxt = NULL; |
| |
| if (vb == NULL) |
| return NULL; |
| |
| if ((user = find_user(vb, username)) != NULL) |
| return srp_user_pwd_dup(user); |
| |
| if ((vb->seed_key == NULL) || |
| (vb->default_g == NULL) || (vb->default_N == NULL)) |
| return NULL; |
| |
| /* if the user is unknown we set parameters as well if we have a seed_key */ |
| |
| if ((user = SRP_user_pwd_new()) == NULL) |
| return NULL; |
| |
| SRP_user_pwd_set_gN(user, vb->default_g, vb->default_N); |
| |
| if (!SRP_user_pwd_set_ids(user, username, NULL)) |
| goto err; |
| |
| if (RAND_bytes(digv, SHA_DIGEST_LENGTH) <= 0) |
| goto err; |
| ctxt = EVP_MD_CTX_new(); |
| if (ctxt == NULL |
| || !EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL) |
| || !EVP_DigestUpdate(ctxt, vb->seed_key, strlen(vb->seed_key)) |
| || !EVP_DigestUpdate(ctxt, username, strlen(username)) |
| || !EVP_DigestFinal_ex(ctxt, digs, NULL)) |
| goto err; |
| EVP_MD_CTX_free(ctxt); |
| ctxt = NULL; |
| if (SRP_user_pwd_set_sv_BN(user, |
| BN_bin2bn(digs, SHA_DIGEST_LENGTH, NULL), |
| BN_bin2bn(digv, SHA_DIGEST_LENGTH, NULL))) |
| return user; |
| |
| err: |
| EVP_MD_CTX_free(ctxt); |
| SRP_user_pwd_free(user); |
| return NULL; |
| } |
| |
| /* |
| * create a verifier (*salt,*verifier,g and N are in base64) |
| */ |
| char *SRP_create_verifier(const char *user, const char *pass, char **salt, |
| char **verifier, const char *N, const char *g) |
| { |
| int len; |
| char *result = NULL, *vf = NULL; |
| const BIGNUM *N_bn = NULL, *g_bn = NULL; |
| BIGNUM *N_bn_alloc = NULL, *g_bn_alloc = NULL, *s = NULL, *v = NULL; |
| unsigned char tmp[MAX_LEN]; |
| unsigned char tmp2[MAX_LEN]; |
| char *defgNid = NULL; |
| int vfsize = 0; |
| |
| if ((user == NULL) || |
| (pass == NULL) || (salt == NULL) || (verifier == NULL)) |
| goto err; |
| |
| if (N) { |
| if ((len = t_fromb64(tmp, sizeof(tmp), N)) <= 0) |
| goto err; |
| N_bn_alloc = BN_bin2bn(tmp, len, NULL); |
| N_bn = N_bn_alloc; |
| if ((len = t_fromb64(tmp, sizeof(tmp) ,g)) <= 0) |
| goto err; |
| g_bn_alloc = BN_bin2bn(tmp, len, NULL); |
| g_bn = g_bn_alloc; |
| defgNid = "*"; |
| } else { |
| SRP_gN *gN = SRP_get_gN_by_id(g, NULL); |
| if (gN == NULL) |
| goto err; |
| N_bn = gN->N; |
| g_bn = gN->g; |
| defgNid = gN->id; |
| } |
| |
| if (*salt == NULL) { |
| if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0) |
| goto err; |
| |
| s = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL); |
| } else { |
| if ((len = t_fromb64(tmp2, sizeof(tmp2), *salt)) <= 0) |
| goto err; |
| s = BN_bin2bn(tmp2, len, NULL); |
| } |
| |
| if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn)) |
| goto err; |
| |
| BN_bn2bin(v, tmp); |
| vfsize = BN_num_bytes(v) * 2; |
| if (((vf = OPENSSL_malloc(vfsize)) == NULL)) |
| goto err; |
| t_tob64(vf, tmp, BN_num_bytes(v)); |
| |
| if (*salt == NULL) { |
| char *tmp_salt; |
| |
| if ((tmp_salt = OPENSSL_malloc(SRP_RANDOM_SALT_LEN * 2)) == NULL) { |
| goto err; |
| } |
| t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN); |
| *salt = tmp_salt; |
| } |
| |
| *verifier = vf; |
| vf = NULL; |
| result = defgNid; |
| |
| err: |
| BN_free(N_bn_alloc); |
| BN_free(g_bn_alloc); |
| OPENSSL_clear_free(vf, vfsize); |
| BN_clear_free(s); |
| BN_clear_free(v); |
| return result; |
| } |
| |
| /* |
| * create a verifier (*salt,*verifier,g and N are BIGNUMs). If *salt != NULL |
| * then the provided salt will be used. On successful exit *verifier will point |
| * to a newly allocated BIGNUM containing the verifier and (if a salt was not |
| * provided) *salt will be populated with a newly allocated BIGNUM containing a |
| * random salt. |
| * The caller is responsible for freeing the allocated *salt and *verifier |
| * BIGNUMS. |
| */ |
| int SRP_create_verifier_BN(const char *user, const char *pass, BIGNUM **salt, |
| BIGNUM **verifier, const BIGNUM *N, |
| const BIGNUM *g) |
| { |
| int result = 0; |
| BIGNUM *x = NULL; |
| BN_CTX *bn_ctx = BN_CTX_new(); |
| unsigned char tmp2[MAX_LEN]; |
| BIGNUM *salttmp = NULL; |
| |
| if ((user == NULL) || |
| (pass == NULL) || |
| (salt == NULL) || |
| (verifier == NULL) || (N == NULL) || (g == NULL) || (bn_ctx == NULL)) |
| goto err; |
| |
| if (*salt == NULL) { |
| if (RAND_bytes(tmp2, SRP_RANDOM_SALT_LEN) <= 0) |
| goto err; |
| |
| salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL); |
| } else { |
| salttmp = *salt; |
| } |
| |
| x = SRP_Calc_x(salttmp, user, pass); |
| |
| *verifier = BN_new(); |
| if (*verifier == NULL) |
| goto err; |
| |
| if (!BN_mod_exp(*verifier, g, x, N, bn_ctx)) { |
| BN_clear_free(*verifier); |
| goto err; |
| } |
| |
| result = 1; |
| *salt = salttmp; |
| |
| err: |
| if (salt != NULL && *salt != salttmp) |
| BN_clear_free(salttmp); |
| BN_clear_free(x); |
| BN_CTX_free(bn_ctx); |
| return result; |
| } |
| |
| #endif |
