/*
- * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2004-2018 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
* 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
+ *
+ * Originally written by Christophe Renou and Peter Sylvester,
+ * for the EdelKey project.
*/
#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
-static char b64table[] =
- "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz./";
-
/*
- * the following two conversion routines have been inspired by code from
- * Stanford
+ * 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)
{
- char *loc;
- int i, j;
- int size;
-
- if (alen == 0 || alen > INT_MAX)
- return -1;
+ EVP_ENCODE_CTX *ctx;
+ int outl = 0, outl2 = 0;
+ size_t size, padsize;
+ const unsigned char *pad = (const unsigned char *)"00";
- while (*src && (*src == ' ' || *src == '\t' || *src == '\n'))
+ while (*src == ' ' || *src == '\t' || *src == '\n')
++src;
size = strlen(src);
- if (size < 0 || size >= (int)alen)
+ padsize = 4 - (size & 3);
+ padsize &= 3;
+
+ /* Four bytes in src become three bytes output. */
+ if (size > INT_MAX || ((size + padsize) / 4) * 3 > alen)
return -1;
- i = 0;
- while (i < size) {
- loc = strchr(b64table, src[i]);
- if (loc == (char *)0)
- break;
- else
- a[i] = loc - b64table;
- ++i;
+ 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;
}
- /* 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;
+
+ /* 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;
}
- while (j <= size && a[j] == 0)
- ++j;
- i = 0;
- while (j <= size)
- a[i++] = a[j++];
- return i;
+
+ 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 char *t_tob64(char *dst, const unsigned char *src, int size)
+static int 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;
+ 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;
}
- 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++];
- }
+ 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';
}
- *dst++ = '\0';
- return olddst;
+ 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;
return NULL;
}
- #if OPENSSL_API_COMPAT < 0x10100000L
+# 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.
{
return find_user(vb, username);
}
-#endif
+# endif
/*
* Ownership of the returned pointer is released to the caller.
if (!SRP_user_pwd_set_ids(user, username, NULL))
goto err;
- if (RAND_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
+ if (RAND_priv_bytes(digv, SHA_DIGEST_LENGTH) <= 0)
goto err;
ctxt = EVP_MD_CTX_new();
if (ctxt == NULL
projects / openssl.git / blobdiff