/*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2018 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
*/
#include <stdio.h>
+#include <assert.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
+#include <openssl/rand_drbg.h>
#include <openssl/engine.h>
#include "internal/evp_int.h"
#include "evp_locl.h"
int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
const unsigned char *key, const unsigned char *iv, int enc)
{
- EVP_CIPHER_CTX_reset(ctx);
+ if (cipher != NULL)
+ EVP_CIPHER_CTX_reset(ctx);
return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
}
if (ctx->cipher->ctx_size) {
ctx->cipher_data = OPENSSL_zalloc(ctx->cipher->ctx_size);
if (ctx->cipher_data == NULL) {
+ ctx->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
return 0;
}
ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
+ ctx->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
return 0;
}
return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
}
-int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
- const unsigned char *in, int inl)
+/*
+ * According to the letter of standard difference between pointers
+ * is specified to be valid only within same object. This makes
+ * it formally challenging to determine if input and output buffers
+ * are not partially overlapping with standard pointer arithmetic.
+ */
+#ifdef PTRDIFF_T
+# undef PTRDIFF_T
+#endif
+#if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
+/*
+ * Then we have VMS that distinguishes itself by adhering to
+ * sizeof(size_t)==4 even in 64-bit builds, which means that
+ * difference between two pointers might be truncated to 32 bits.
+ * In the context one can even wonder how comparison for
+ * equality is implemented. To be on the safe side we adhere to
+ * PTRDIFF_T even for comparison for equality.
+ */
+# define PTRDIFF_T uint64_t
+#else
+# define PTRDIFF_T size_t
+#endif
+
+int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
+{
+ PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
+ /*
+ * Check for partially overlapping buffers. [Binary logical
+ * operations are used instead of boolean to minimize number
+ * of conditional branches.]
+ */
+ int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
+ (diff > (0 - (PTRDIFF_T)len)));
+
+ return overlapped;
+}
+
+static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
+ unsigned char *out, int *outl,
+ const unsigned char *in, int inl)
{
- int i, j, bl;
+ int i, j, bl, cmpl = inl;
+
+ if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
+ cmpl = (cmpl + 7) / 8;
+
+ bl = ctx->cipher->block_size;
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
+ /* If block size > 1 then the cipher will have to do this check */
+ if (bl == 1 && is_partially_overlapping(out, in, cmpl)) {
+ EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
+ return 0;
+ }
+
i = ctx->cipher->do_cipher(ctx, out, in, inl);
if (i < 0)
return 0;
*outl = 0;
return inl == 0;
}
+ if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {
+ EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
+ return 0;
+ }
if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
}
}
i = ctx->buf_len;
- bl = ctx->cipher->block_size;
OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
if (i != 0) {
if (bl - i > inl) {
} else {
j = bl - i;
memcpy(&(ctx->buf[i]), in, j);
- if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
- return 0;
inl -= j;
in += j;
+ if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
+ return 0;
out += bl;
*outl = bl;
}
return 1;
}
+
+int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
+ const unsigned char *in, int inl)
+{
+ /* Prevent accidental use of decryption context when encrypting */
+ if (!ctx->encrypt) {
+ EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_INVALID_OPERATION);
+ return 0;
+ }
+
+ return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
+}
+
int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
int ret;
int n, ret;
unsigned int i, b, bl;
+ /* Prevent accidental use of decryption context when encrypting */
+ if (!ctx->encrypt) {
+ EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
+ return 0;
+ }
+
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
if (ret < 0)
}
b = ctx->cipher->block_size;
- OPENSSL_assert(b <= sizeof ctx->buf);
+ OPENSSL_assert(b <= sizeof(ctx->buf));
if (b == 1) {
*outl = 0;
return 1;
int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
const unsigned char *in, int inl)
{
- int fix_len;
+ int fix_len, cmpl = inl;
unsigned int b;
+ /* Prevent accidental use of encryption context when decrypting */
+ if (ctx->encrypt) {
+ EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_INVALID_OPERATION);
+ return 0;
+ }
+
+ b = ctx->cipher->block_size;
+
+ if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
+ cmpl = (cmpl + 7) / 8;
+
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
+ if (b == 1 && is_partially_overlapping(out, in, cmpl)) {
+ EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
+ return 0;
+ }
+
fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
if (fix_len < 0) {
*outl = 0;
}
if (ctx->flags & EVP_CIPH_NO_PADDING)
- return EVP_EncryptUpdate(ctx, out, outl, in, inl);
+ return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);
- b = ctx->cipher->block_size;
- OPENSSL_assert(b <= sizeof ctx->final);
+ OPENSSL_assert(b <= sizeof(ctx->final));
if (ctx->final_used) {
+ /* see comment about PTRDIFF_T comparison above */
+ if (((PTRDIFF_T)out == (PTRDIFF_T)in)
+ || is_partially_overlapping(out, in, b)) {
+ EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
+ return 0;
+ }
memcpy(out, ctx->final, b);
out += b;
fix_len = 1;
} else
fix_len = 0;
- if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))
+ if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))
return 0;
/*
{
int i, n;
unsigned int b;
+
+ /* Prevent accidental use of encryption context when decrypting */
+ if (ctx->encrypt) {
+ EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_INVALID_OPERATION);
+ return 0;
+ }
+
*outl = 0;
if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
if (b > 1) {
if (ctx->buf_len || !ctx->final_used) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
- return (0);
+ return 0;
}
- OPENSSL_assert(b <= sizeof ctx->final);
+ OPENSSL_assert(b <= sizeof(ctx->final));
/*
* The following assumes that the ciphertext has been authenticated.
n = ctx->final[b - 1];
if (n == 0 || n > (int)b) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
- return (0);
+ return 0;
}
for (i = 0; i < n; i++) {
if (ctx->final[--b] != n) {
EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
- return (0);
+ return 0;
}
}
n = ctx->cipher->block_size - n;
*outl = n;
} else
*outl = 0;
- return (1);
+ return 1;
}
int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
int ret;
+
if (!ctx->cipher) {
EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
return 0;
{
if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
- if (RAND_bytes(key, ctx->key_len) <= 0)
+ if (RAND_priv_bytes(key, ctx->key_len) <= 0)
return 0;
return 1;
}
if (in->cipher_data && in->cipher->ctx_size) {
out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
if (out->cipher_data == NULL) {
+ out->cipher = NULL;
EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
return 0;
}
}
if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
- return in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out);
+ if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
+ out->cipher = NULL;
+ EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
+ return 0;
+ }
return 1;
}