Commit dcb982d7 authored by Richard Levitte's avatar Richard Levitte
Browse files

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: default avatarPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8676)
parent ccf45361

crypto/evp/evp_enc.c

+10 −9
Original line number Diff line number Diff line
@@ -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);