Commit a8bf2f8f authored by Richard Levitte's avatar Richard Levitte
Browse files

Prevent calling decryption in an encryption context and vice versa 



Reviewed-by: default avatarKurt Roeckx <kurt@roeckx.be>
Reviewed-by: default avatarPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7852)
parent 1057c2c3

crypto/evp/evp_enc.c

+39 −6
Original line number Diff line number Diff line
@@ -294,7 +294,8 @@ int is_partially_overlapping(const void *ptr1, const void *ptr2, int len) 
    return overlapped;

}



int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,

static int evp_EncryptDecryptUpdate(EVP_CIPHER_CTX *ctx,

                                    unsigned char *out, int *outl,

                                    const unsigned char *in, int inl)

{

    int i, j, bl, cmpl = inl;
@@ -307,7 +308,7 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
    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_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);

            EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);

            return 0;

        }
@@ -324,7 +325,7 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
        return inl == 0;

    }

    if (is_partially_overlapping(out + ctx->buf_len, in, cmpl)) {

        EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);

        EVPerr(EVP_F_EVP_ENCRYPTDECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);

        return 0;

    }
@@ -371,6 +372,19 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
    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;
@@ -383,6 +397,12 @@ int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) 
    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)
@@ -426,6 +446,12 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
    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))
@@ -452,7 +478,7 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
    }



    if (ctx->flags & EVP_CIPH_NO_PADDING)

        return EVP_EncryptUpdate(ctx, out, outl, in, inl);

        return evp_EncryptDecryptUpdate(ctx, out, outl, in, inl);



    OPENSSL_assert(b <= sizeof(ctx->final));
@@ -469,7 +495,7 @@ int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl, 
    } else

        fix_len = 0;



    if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))

    if (!evp_EncryptDecryptUpdate(ctx, out, outl, in, inl))

        return 0;



    /*
@@ -500,6 +526,13 @@ int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl) 
{

    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) {