Commit 5e4bbeb4 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

modes/ctr128.c: pay attention to ecount_buf alignment in CRYPTO_ctr128_encrypt. 



It's never problem if CRYPTO_ctr128_encrypt is called from EVP, because
buffer in question is always aligned within EVP_CIPHER_CTX structure.

RT#4218

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent 3c65577f

crypto/modes/ctr128.c

+17 −24
Original line number Diff line number Diff line
@@ -67,23 +67,20 @@ 
/* increment counter (128-bit int) by 1 */

static void ctr128_inc(unsigned char *counter)

{

    u32 n = 16;

    u8 c;

    u32 n = 16, c = 1;



    do {

        --n;

        c = counter[n];

        ++c;

        counter[n] = c;

        if (c)

            return;

        c += counter[n];

        counter[n] = (u8)c;

        c >>= 8;

    } while (n);

}



#if !defined(OPENSSL_SMALL_FOOTPRINT)

static void ctr128_inc_aligned(unsigned char *counter)

{

    size_t *data, c, n;

    size_t *data, c, d, n;

    const union {

        long one;

        char little;
@@ -91,20 +88,19 @@ static void ctr128_inc_aligned(unsigned char *counter) 
        1

    };



    if (is_endian.little) {

    if (is_endian.little || ((size_t)counter % sizeof(size_t)) != 0) {

        ctr128_inc(counter);

        return;

    }



    data = (size_t *)counter;

    c = 1;

    n = 16 / sizeof(size_t);

    do {

        --n;

        c = data[n];

        ++c;

        data[n] = c;

        if (c)

            return;

        d = data[n] += c;

        /* did addition carry? */

        c = ((d - c) ^ d) >> (sizeof(size_t) * 8 - 1);

    } while (n);

}

#endif
@@ -144,14 +140,14 @@ void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out, 
            }



# if defined(STRICT_ALIGNMENT)

            if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) !=

                0)

            if (((size_t)in | (size_t)out | (size_t)ecount_buf)

                % sizeof(size_t) != 0)

                break;

# endif

            while (len >= 16) {

                (*block) (ivec, ecount_buf, key);

                ctr128_inc_aligned(ivec);

                for (; n < 16; n += sizeof(size_t))

                for (n = 0; n < 16; n += sizeof(size_t))

                    *(size_t *)(out + n) =

                        *(size_t *)(in + n) ^ *(size_t *)(ecount_buf + n);

                len -= 16;
@@ -189,16 +185,13 @@ void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out, 
/* increment upper 96 bits of 128-bit counter by 1 */

static void ctr96_inc(unsigned char *counter)

{

    u32 n = 12;

    u8 c;

    u32 n = 12, c = 1;



    do {

        --n;

        c = counter[n];

        ++c;

        counter[n] = c;

        if (c)

            return;

        c += counter[n];

        counter[n] = (u8)c;

        c >>= 8;

    } while (n);

}