/*
- * Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2004-2019 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2004, EdelKey Project. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
#ifndef OPENSSL_NO_SRP
# include "internal/cryptlib.h"
+# include "internal/evp_int.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>
+# include <openssl/err.h>
# define SRP_RANDOM_SALT_LEN 20
# define MAX_LEN 2500
+/*
+ * Note that SRP uses its own variant of base 64 encoding. A different base64
+ * alphabet is used and no padding '=' characters are added. Instead we pad to
+ * the front with 0 bytes and subsequently strip off leading encoded padding.
+ * This variant is used for compatibility with other SRP implementations -
+ * notably libsrp, but also others. It is also required for backwards
+ * compatibility in order to load verifier files from other OpenSSL versions.
+ */
+
/*
* Convert a base64 string into raw byte array representation.
+ * Returns the length of the decoded data, or -1 on error.
*/
static int t_fromb64(unsigned char *a, size_t alen, const char *src)
{
- size_t size = strlen(src);
+ EVP_ENCODE_CTX *ctx;
+ int outl = 0, outl2 = 0;
+ size_t size, padsize;
+ const unsigned char *pad = (const unsigned char *)"00";
+
+ while (*src == ' ' || *src == '\t' || *src == '\n')
+ ++src;
+ size = strlen(src);
+ padsize = 4 - (size & 3);
+ padsize &= 3;
/* Four bytes in src become three bytes output. */
- if (size > INT_MAX || (size / 4) * 3 > alen)
+ if (size > INT_MAX || ((size + padsize) / 4) * 3 > alen)
return -1;
- return EVP_DecodeBlock(a, (unsigned char *)src, (int)size);
+ ctx = EVP_ENCODE_CTX_new();
+ if (ctx == NULL)
+ return -1;
+
+ /*
+ * This should never occur because 1 byte of data always requires 2 bytes of
+ * encoding, i.e.
+ * 0 bytes unencoded = 0 bytes encoded
+ * 1 byte unencoded = 2 bytes encoded
+ * 2 bytes unencoded = 3 bytes encoded
+ * 3 bytes unencoded = 4 bytes encoded
+ * 4 bytes unencoded = 6 bytes encoded
+ * etc
+ */
+ if (padsize == 3) {
+ outl = -1;
+ goto err;
+ }
+
+ /* Valid padsize values are now 0, 1 or 2 */
+
+ EVP_DecodeInit(ctx);
+ evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+ /* Add any encoded padding that is required */
+ if (padsize != 0
+ && EVP_DecodeUpdate(ctx, a, &outl, pad, padsize) < 0) {
+ outl = -1;
+ goto err;
+ }
+ if (EVP_DecodeUpdate(ctx, a, &outl2, (const unsigned char *)src, size) < 0) {
+ outl = -1;
+ goto err;
+ }
+ outl += outl2;
+ EVP_DecodeFinal(ctx, a + outl, &outl2);
+ outl += outl2;
+
+ /* Strip off the leading padding */
+ if (padsize != 0) {
+ if ((int)padsize >= outl) {
+ outl = -1;
+ goto err;
+ }
+
+ /*
+ * If we added 1 byte of padding prior to encoding then we have 2 bytes
+ * of "real" data which gets spread across 4 encoded bytes like this:
+ * (6 bits pad)(2 bits pad | 4 bits data)(6 bits data)(6 bits data)
+ * So 1 byte of pre-encoding padding results in 1 full byte of encoded
+ * padding.
+ * If we added 2 bytes of padding prior to encoding this gets encoded
+ * as:
+ * (6 bits pad)(6 bits pad)(4 bits pad | 2 bits data)(6 bits data)
+ * So 2 bytes of pre-encoding padding results in 2 full bytes of encoded
+ * padding, i.e. we have to strip the same number of bytes of padding
+ * from the encoded data as we added to the pre-encoded data.
+ */
+ memmove(a, a + padsize, outl - padsize);
+ outl -= padsize;
+ }
+
+ err:
+ EVP_ENCODE_CTX_free(ctx);
+
+ return outl;
}
/*
* Convert a raw byte string into a null-terminated base64 ASCII string.
+ * Returns 1 on success or 0 on error.
*/
-static void t_tob64(char *dst, const unsigned char *src, int size)
+static int t_tob64(char *dst, const unsigned char *src, int size)
{
- EVP_EncodeBlock((unsigned char *)dst, src, size);
+ EVP_ENCODE_CTX *ctx = EVP_ENCODE_CTX_new();
+ int outl = 0, outl2 = 0;
+ unsigned char pad[2] = {0, 0};
+ size_t leadz = 0;
+
+ if (ctx == NULL)
+ return 0;
+
+ EVP_EncodeInit(ctx);
+ evp_encode_ctx_set_flags(ctx, EVP_ENCODE_CTX_NO_NEWLINES
+ | EVP_ENCODE_CTX_USE_SRP_ALPHABET);
+
+ /*
+ * We pad at the front with zero bytes until the length is a multiple of 3
+ * so that EVP_EncodeUpdate/EVP_EncodeFinal does not add any of its own "="
+ * padding
+ */
+ leadz = 3 - (size % 3);
+ if (leadz != 3
+ && !EVP_EncodeUpdate(ctx, (unsigned char *)dst, &outl, pad,
+ leadz)) {
+ EVP_ENCODE_CTX_free(ctx);
+ return 0;
+ }
+
+ if (!EVP_EncodeUpdate(ctx, (unsigned char *)dst + outl, &outl2, src,
+ size)) {
+ EVP_ENCODE_CTX_free(ctx);
+ return 0;
+ }
+ outl += outl2;
+ EVP_EncodeFinal(ctx, (unsigned char *)dst + outl, &outl2);
+ outl += outl2;
+
+ /* Strip the encoded padding at the front */
+ if (leadz != 3) {
+ memmove(dst, dst + leadz, outl - leadz);
+ dst[outl - leadz] = '\0';
+ }
+
+ EVP_ENCODE_CTX_free(ctx);
+ return 1;
}
void SRP_user_pwd_free(SRP_user_pwd *user_pwd)
static SRP_user_pwd *SRP_user_pwd_new(void)
{
- SRP_user_pwd *ret = OPENSSL_malloc(sizeof(*ret));
- if (ret == NULL)
+ SRP_user_pwd *ret;
+
+ if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) {
+ /* SRPerr(SRP_F_SRP_USER_PWD_NEW, ERR_R_MALLOC_FAILURE); */ /*ckerr_ignore*/
return NULL;
+ }
ret->N = NULL;
ret->g = NULL;
ret->s = NULL;
if ((len = t_fromb64(tmp, sizeof(tmp), N)) <= 0)
goto err;
N_bn_alloc = BN_bin2bn(tmp, len, NULL);
+ if (N_bn_alloc == NULL)
+ goto err;
N_bn = N_bn_alloc;
if ((len = t_fromb64(tmp, sizeof(tmp) ,g)) <= 0)
goto err;
g_bn_alloc = BN_bin2bn(tmp, len, NULL);
+ if (g_bn_alloc == NULL)
+ goto err;
g_bn = g_bn_alloc;
defgNid = "*";
} else {
goto err;
s = BN_bin2bn(tmp2, len, NULL);
}
+ if (s == NULL)
+ goto err;
if (!SRP_create_verifier_BN(user, pass, &s, &v, N_bn, g_bn))
goto err;
- BN_bn2bin(v, tmp);
+ if (BN_bn2bin(v, tmp) < 0)
+ goto err;
vfsize = BN_num_bytes(v) * 2;
if (((vf = OPENSSL_malloc(vfsize)) == NULL))
goto err;
- t_tob64(vf, tmp, BN_num_bytes(v));
+ if (!t_tob64(vf, tmp, BN_num_bytes(v)))
+ goto err;
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);
+ if (!t_tob64(tmp_salt, tmp2, SRP_RANDOM_SALT_LEN)) {
+ OPENSSL_free(tmp_salt);
+ goto err;
+ }
*salt = tmp_salt;
}
goto err;
salttmp = BN_bin2bn(tmp2, SRP_RANDOM_SALT_LEN, NULL);
+ if (salttmp == NULL)
+ goto err;
} else {
salttmp = *salt;
}
x = SRP_Calc_x(salttmp, user, pass);
+ if (x == NULL)
+ goto err;
*verifier = BN_new();
if (*verifier == NULL)
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