EVP_*Update: ensure that input NULL with length 0 isn't passed

Even with custome ciphers, the combination in == NULL && inl == 0
should not be passed down to the backend cipher function.  The reason
is that these are the values passed by EVP_*Final, and some of the
backend cipher functions do check for these to see if a "final" call
is made.

Fixes #8675

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8676)

(cherry picked from commit dcb982d792)
This commit is contained in:
Richard Levitte 2019-04-05 01:22:14 +02:00
parent 5fba3afad0
commit 130b7df2db

View file

@ -305,6 +305,11 @@ static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
bl = ctx->cipher->block_size;
if (inl <= 0) {
*outl = 0;
return inl == 0;
}
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)) {
@ -320,10 +325,6 @@ static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,
return 1;
}
if (inl <= 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;
@ -457,6 +458,11 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
if (EVP_CIPHER_CTX_test_flags(ctx, EVP_CIPH_FLAG_LENGTH_BITS))
cmpl = (cmpl + 7) / 8;
if (inl <= 0) {
*outl = 0;
return inl == 0;
}
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);
@ -472,11 +478,6 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
return 1;
}
if (inl <= 0) {
*outl = 0;
return inl == 0;
}
if (ctx->flags & EVP_CIPH_NO_PADDING)
return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);