aes_modes.c

AES加密算法C语言实现

            *obuf++ = iv[b_pos++] ^= *ibuf++, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    if((nb = (len - cnt) >> 4) != 0)    /* process whole blocks */
    {
#if defined( USE_VIA_ACE_IF_PRESENT )

        if(ctx->inf.b[1] == 0xff)
        {   int m;
            uint_8t *ksp = (uint_8t*)(ctx->ks), *ivp = iv;
            aligned_auto(uint_8t, liv, AES_BLOCK_SIZE, 16);
            via_cwd(cwd, hybrid, enc, 2 * ctx->inf.b[0] - 192);

            if(addr_offset( ctx, 16 ))
                return EXIT_FAILURE;

            if(addr_offset( iv, 16 ))   /* ensure an aligned iv */
            {
                ivp = liv;
                memcpy(liv, iv, AES_BLOCK_SIZE);
            }

            if(!addr_offset( ibuf, 16 ) && !addr_offset( obuf, 16 ))
            {
                via_cfb_op7(ksp, cwd, ibuf, obuf, nb, ivp, ivp);
                ibuf += nb * AES_BLOCK_SIZE;
                obuf += nb * AES_BLOCK_SIZE;
                cnt  += nb * AES_BLOCK_SIZE;
            }
            else    /* input, output or both are unaligned  */
            {   aligned_auto(uint_8t, buf, BFR_BLOCKS * AES_BLOCK_SIZE, 16);
                uint_8t *ip, *op;

                while(nb)
                {
                    m = (nb > BFR_BLOCKS ? BFR_BLOCKS : nb), nb -= m;

                    ip = (addr_offset( ibuf, 16 ) ? buf : (uint_8t*)ibuf);
                    op = (addr_offset( obuf, 16 ) ? buf : obuf);

                    if(ip != ibuf)
                        memcpy(buf, ibuf, m * AES_BLOCK_SIZE);

                    via_cfb_op7(ksp, cwd, ip, op, m, ivp, ivp);

                    if(op != obuf)
                        memcpy(obuf, buf, m * AES_BLOCK_SIZE);

                    ibuf += m * AES_BLOCK_SIZE;
                    obuf += m * AES_BLOCK_SIZE;
                    cnt  += m * AES_BLOCK_SIZE;
                }
            }

            if(ivp != iv)
                memcpy(iv, ivp, AES_BLOCK_SIZE);
        }
#else
# ifdef FAST_BUFFER_OPERATIONS
        if(!addr_offset( ibuf, 4 ) && !addr_offset( obuf, 4 ) && !addr_offset( iv, 4 ))
            while(cnt + AES_BLOCK_SIZE <= len)
            {
                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                lp32(obuf)[0] = lp32(iv)[0] ^= lp32(ibuf)[0];
                lp32(obuf)[1] = lp32(iv)[1] ^= lp32(ibuf)[1];
                lp32(obuf)[2] = lp32(iv)[2] ^= lp32(ibuf)[2];
                lp32(obuf)[3] = lp32(iv)[3] ^= lp32(ibuf)[3];
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
        else
# endif
            while(cnt + AES_BLOCK_SIZE <= len)
            {
                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                obuf[ 0] = iv[ 0] ^= ibuf[ 0]; obuf[ 1] = iv[ 1] ^= ibuf[ 1];
                obuf[ 2] = iv[ 2] ^= ibuf[ 2]; obuf[ 3] = iv[ 3] ^= ibuf[ 3];
                obuf[ 4] = iv[ 4] ^= ibuf[ 4]; obuf[ 5] = iv[ 5] ^= ibuf[ 5];
                obuf[ 6] = iv[ 6] ^= ibuf[ 6]; obuf[ 7] = iv[ 7] ^= ibuf[ 7];
                obuf[ 8] = iv[ 8] ^= ibuf[ 8]; obuf[ 9] = iv[ 9] ^= ibuf[ 9];
                obuf[10] = iv[10] ^= ibuf[10]; obuf[11] = iv[11] ^= ibuf[11];
                obuf[12] = iv[12] ^= ibuf[12]; obuf[13] = iv[13] ^= ibuf[13];
                obuf[14] = iv[14] ^= ibuf[14]; obuf[15] = iv[15] ^= ibuf[15];
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
#endif
    }

    while(cnt < len)
    {
        if(!b_pos)
            aes_ecb_encrypt(iv, iv, AES_BLOCK_SIZE, ctx);

        while(cnt < len && b_pos < AES_BLOCK_SIZE)
            *obuf++ = iv[b_pos++] ^= *ibuf++, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    ctx->inf.b[2] = b_pos;
    return EXIT_SUCCESS;
}

AES_RETURN aes_cfb_decrypt(const unsigned char *ibuf, unsigned char *obuf,
                    int len, unsigned char *iv, aes_encrypt_ctx ctx[1])
{   int cnt = 0, b_pos = (int)ctx->inf.b[2], nb;

    if(b_pos)           /* complete any partial block   */
    {   uint_8t t;

        while(b_pos < AES_BLOCK_SIZE && cnt < len)
            t = *ibuf++, *obuf++ = t ^ iv[b_pos], iv[b_pos++] = t, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    if((nb = (len - cnt) >> 4) != 0)    /* process whole blocks */
    {
#if defined( USE_VIA_ACE_IF_PRESENT )

        if(ctx->inf.b[1] == 0xff)
        {   int m;
            uint_8t *ksp = (uint_8t*)(ctx->ks), *ivp = iv;
            aligned_auto(uint_8t, liv, AES_BLOCK_SIZE, 16);
            via_cwd(cwd, hybrid, dec, 2 * ctx->inf.b[0] - 192);

            if(addr_offset( ctx, 16 ))
                return EXIT_FAILURE;

            if(addr_offset( iv, 16 ))   /* ensure an aligned iv */
            {
                ivp = liv;
                memcpy(liv, iv, AES_BLOCK_SIZE);
            }

            if(!addr_offset( ibuf, 16 ) && !addr_offset( obuf, 16 ))
            {
                via_cfb_op6(ksp, cwd, ibuf, obuf, nb, ivp);
                ibuf += nb * AES_BLOCK_SIZE;
                obuf += nb * AES_BLOCK_SIZE;
                cnt  += nb * AES_BLOCK_SIZE;
            }
            else    /* input, output or both are unaligned  */
            {   aligned_auto(uint_8t, buf, BFR_BLOCKS * AES_BLOCK_SIZE, 16);
                uint_8t *ip, *op;

                while(nb)
                {
                    m = (nb > BFR_BLOCKS ? BFR_BLOCKS : nb), nb -= m;

                    ip = (addr_offset( ibuf, 16 ) ? buf : (uint_8t*)ibuf);
                    op = (addr_offset( obuf, 16 ) ? buf : op);

                    if(ip != ibuf)
                        memcpy(buf, ibuf, m * AES_BLOCK_SIZE);

                    via_cfb_op6(ksp, cwd, ip, op, m, ivp);

                    if(op != obuf)
                        memcpy(obuf, buf, m * AES_BLOCK_SIZE);

                    ibuf += m * AES_BLOCK_SIZE;
                    obuf += m * AES_BLOCK_SIZE;
                    cnt  += m * AES_BLOCK_SIZE;
                }
            }

            if(ivp != iv)
                memcpy(iv, ivp, AES_BLOCK_SIZE);
        }
#else
# ifdef FAST_BUFFER_OPERATIONS
        if(!addr_offset( ibuf, 4 ) && !addr_offset( obuf, 4 ) &&!addr_offset( iv, 4 ))
            while(cnt + AES_BLOCK_SIZE <= len)
            {   uint_32t t;

                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                t = lp32(ibuf)[0], lp32(obuf)[0] = t ^ lp32(iv)[0], lp32(iv)[0] = t;
                t = lp32(ibuf)[1], lp32(obuf)[1] = t ^ lp32(iv)[1], lp32(iv)[1] = t;
                t = lp32(ibuf)[2], lp32(obuf)[2] = t ^ lp32(iv)[2], lp32(iv)[2] = t;
                t = lp32(ibuf)[3], lp32(obuf)[3] = t ^ lp32(iv)[3], lp32(iv)[3] = t;
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
        else
# endif
            while(cnt + AES_BLOCK_SIZE <= len)
            {   uint_8t t;

                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                t = ibuf[ 0], obuf[ 0] = t ^ iv[ 0], iv[ 0] = t;
                t = ibuf[ 1], obuf[ 1] = t ^ iv[ 1], iv[ 1] = t;
                t = ibuf[ 2], obuf[ 2] = t ^ iv[ 2], iv[ 2] = t;
                t = ibuf[ 3], obuf[ 3] = t ^ iv[ 3], iv[ 3] = t;
                t = ibuf[ 4], obuf[ 4] = t ^ iv[ 4], iv[ 4] = t;
                t = ibuf[ 5], obuf[ 5] = t ^ iv[ 5], iv[ 5] = t;
                t = ibuf[ 6], obuf[ 6] = t ^ iv[ 6], iv[ 6] = t;
                t = ibuf[ 7], obuf[ 7] = t ^ iv[ 7], iv[ 7] = t;
                t = ibuf[ 8], obuf[ 8] = t ^ iv[ 8], iv[ 8] = t;
                t = ibuf[ 9], obuf[ 9] = t ^ iv[ 9], iv[ 9] = t;
                t = ibuf[10], obuf[10] = t ^ iv[10], iv[10] = t;
                t = ibuf[11], obuf[11] = t ^ iv[11], iv[11] = t;
                t = ibuf[12], obuf[12] = t ^ iv[12], iv[12] = t;
                t = ibuf[13], obuf[13] = t ^ iv[13], iv[13] = t;
                t = ibuf[14], obuf[14] = t ^ iv[14], iv[14] = t;
                t = ibuf[15], obuf[15] = t ^ iv[15], iv[15] = t;
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
#endif
    }

    while(cnt < len)
    {   uint_8t t;

        if(!b_pos)
            aes_ecb_encrypt(iv, iv, AES_BLOCK_SIZE, ctx);

        while(cnt < len && b_pos < AES_BLOCK_SIZE)
            t = *ibuf++, *obuf++ = t ^ iv[b_pos], iv[b_pos++] = t, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    ctx->inf.b[2] = b_pos;
    return EXIT_SUCCESS;
}

AES_RETURN aes_ofb_crypt(const unsigned char *ibuf, unsigned char *obuf,
                    int len, unsigned char *iv, aes_encrypt_ctx ctx[1])
{   int cnt = 0, b_pos = (int)ctx->inf.b[2], nb;

    if(b_pos)           /* complete any partial block   */
    {
        while(b_pos < AES_BLOCK_SIZE && cnt < len)
            *obuf++ = iv[b_pos++] ^ *ibuf++, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    if((nb = (len - cnt) >> 4) != 0)   /* process whole blocks */
    {
#if defined( USE_VIA_ACE_IF_PRESENT )

        if(ctx->inf.b[1] == 0xff)
        {   int m;
            uint_8t *ksp = (uint_8t*)(ctx->ks), *ivp = iv;
            aligned_auto(uint_8t, liv, AES_BLOCK_SIZE, 16);
            via_cwd(cwd, hybrid, enc, 2 * ctx->inf.b[0] - 192);

            if(addr_offset( ctx, 16 ))
                return EXIT_FAILURE;

            if(addr_offset( iv, 16 ))   /* ensure an aligned iv */
            {
                ivp = liv;
                memcpy(liv, iv, AES_BLOCK_SIZE);
            }

            if(!addr_offset( ibuf, 16 ) && !addr_offset( obuf, 16 ))
            {
                via_ofb_op6(ksp, cwd, ibuf, obuf, nb, ivp);
                ibuf += nb * AES_BLOCK_SIZE;
                obuf += nb * AES_BLOCK_SIZE;
                cnt  += nb * AES_BLOCK_SIZE;
            }
            else    /* input, output or both are unaligned  */
        {   aligned_auto(uint_8t, buf, BFR_BLOCKS * AES_BLOCK_SIZE, 16);
            uint_8t *ip, *op;

                while(nb)
                {
                    m = (nb > BFR_BLOCKS ? BFR_BLOCKS : nb), nb -= m;

                    ip = (addr_offset( ibuf, 16 ) ? buf : (uint_8t*)ibuf);
                    op = (addr_offset( obuf, 16 ) ? buf : obuf);

                    if(ip != ibuf)
                        memcpy(buf, ibuf, m * AES_BLOCK_SIZE);

                    via_ofb_op6(ksp, cwd, ip, op, m, ivp);

                    if(op != obuf)
                        memcpy(obuf, buf, m * AES_BLOCK_SIZE);

                    ibuf += m * AES_BLOCK_SIZE;
                    obuf += m * AES_BLOCK_SIZE;
                    cnt  += m * AES_BLOCK_SIZE;
                }
            }

            if(ivp != iv)
                memcpy(iv, ivp, AES_BLOCK_SIZE);
        }
#else
# ifdef FAST_BUFFER_OPERATIONS
        if(!addr_offset( ibuf, 4 ) && !addr_offset( obuf, 4 ) && !addr_offset( iv, 4 ))
            while(cnt + AES_BLOCK_SIZE <= len)
            {
                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                lp32(obuf)[0] = lp32(iv)[0] ^ lp32(ibuf)[0];
                lp32(obuf)[1] = lp32(iv)[1] ^ lp32(ibuf)[1];
                lp32(obuf)[2] = lp32(iv)[2] ^ lp32(ibuf)[2];
                lp32(obuf)[3] = lp32(iv)[3] ^ lp32(ibuf)[3];
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
        else
# endif
            while(cnt + AES_BLOCK_SIZE <= len)
            {
                assert(b_pos == 0);
                aes_encrypt(iv, iv, ctx);
                obuf[ 0] = iv[ 0] ^ ibuf[ 0]; obuf[ 1] = iv[ 1] ^ ibuf[ 1];
                obuf[ 2] = iv[ 2] ^ ibuf[ 2]; obuf[ 3] = iv[ 3] ^ ibuf[ 3];
                obuf[ 4] = iv[ 4] ^ ibuf[ 4]; obuf[ 5] = iv[ 5] ^ ibuf[ 5];
                obuf[ 6] = iv[ 6] ^ ibuf[ 6]; obuf[ 7] = iv[ 7] ^ ibuf[ 7];
                obuf[ 8] = iv[ 8] ^ ibuf[ 8]; obuf[ 9] = iv[ 9] ^ ibuf[ 9];
                obuf[10] = iv[10] ^ ibuf[10]; obuf[11] = iv[11] ^ ibuf[11];
                obuf[12] = iv[12] ^ ibuf[12]; obuf[13] = iv[13] ^ ibuf[13];
                obuf[14] = iv[14] ^ ibuf[14]; obuf[15] = iv[15] ^ ibuf[15];
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
                cnt  += AES_BLOCK_SIZE;
            }
#endif
    }

    while(cnt < len)
    {
        if(!b_pos)
            aes_ecb_encrypt(iv, iv, AES_BLOCK_SIZE, ctx);

        while(cnt < len && b_pos < AES_BLOCK_SIZE)
            *obuf++ = iv[b_pos++] ^ *ibuf++, cnt++;

        b_pos = (b_pos == AES_BLOCK_SIZE ? 0 : b_pos);
    }

    ctx->inf.b[2] = b_pos;
    return EXIT_SUCCESS;
}

#define BFR_LENGTH  (BFR_BLOCKS * AES_BLOCK_SIZE)

AES_RETURN aes_ctr_crypt(const unsigned char *ibuf, unsigned char *obuf,
            int len, unsigned char *cbuf, cbuf_inc ctr_inc, aes_encrypt_ctx ctx[1])
{   uint_8t *ip;
    int     i, blen, b_pos = (int)(ctx->inf.b[2]);

#if defined( USE_VIA_ACE_IF_PRESENT )
    aligned_auto(uint_8t, buf, BFR_LENGTH, 16);
    if(ctx->inf.b[1] == 0xff && addr_offset( ctx, 16 ))
        return EXIT_FAILURE;
#else
    uint_8t buf[BFR_LENGTH];
#endif

    if(b_pos)
    {
        memcpy(buf, cbuf, AES_BLOCK_SIZE);
        aes_ecb_encrypt(buf, buf, AES_BLOCK_SIZE, ctx);
        while(b_pos < AES_BLOCK_SIZE && len)
            *obuf++ = *ibuf++ ^ buf[b_pos++], --len;
        if(len)
            ctr_inc(cbuf), b_pos = 0;
    }

    while(len)
    {
        blen = (len > BFR_LENGTH ? BFR_LENGTH : len), len -= blen;

        for(i = 0, ip = buf; i < (blen >> 4); ++i)
        {
            memcpy(ip, cbuf, AES_BLOCK_SIZE);
            ctr_inc(cbuf);
            ip += AES_BLOCK_SIZE;
        }

        if(blen & (AES_BLOCK_SIZE - 1))
            memcpy(ip, cbuf, AES_BLOCK_SIZE), i++;

#if defined( USE_VIA_ACE_IF_PRESENT )
        if(ctx->inf.b[1] == 0xff)
        {
            via_cwd(cwd, hybrid, enc, 2 * ctx->inf.b[0] - 192);
            via_ecb_op5((ctx->ks),cwd,buf,buf,i);
        }
        else
#endif
        aes_ecb_encrypt(buf, buf, i * AES_BLOCK_SIZE, ctx);

        i = 0; ip = buf;
# ifdef FAST_BUFFER_OPERATIONS
        if(!addr_offset( ibuf, 4 ) && !addr_offset( obuf, 4 ) && !addr_offset( ip, 4 ))
            while(i + AES_BLOCK_SIZE <= blen)
            {
                lp32(obuf)[0] = lp32(ibuf)[0] ^ lp32(ip)[0];
                lp32(obuf)[1] = lp32(ibuf)[1] ^ lp32(ip)[1];
                lp32(obuf)[2] = lp32(ibuf)[2] ^ lp32(ip)[2];
                lp32(obuf)[3] = lp32(ibuf)[3] ^ lp32(ip)[3];
                i += AES_BLOCK_SIZE;
                ip += AES_BLOCK_SIZE;
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
            }
        else
#endif
            while(i + AES_BLOCK_SIZE <= blen)
            {
                obuf[ 0] = ibuf[ 0] ^ ip[ 0]; obuf[ 1] = ibuf[ 1] ^ ip[ 1];
                obuf[ 2] = ibuf[ 2] ^ ip[ 2]; obuf[ 3] = ibuf[ 3] ^ ip[ 3];
                obuf[ 4] = ibuf[ 4] ^ ip[ 4]; obuf[ 5] = ibuf[ 5] ^ ip[ 5];
                obuf[ 6] = ibuf[ 6] ^ ip[ 6]; obuf[ 7] = ibuf[ 7] ^ ip[ 7];
                obuf[ 8] = ibuf[ 8] ^ ip[ 8]; obuf[ 9] = ibuf[ 9] ^ ip[ 9];
                obuf[10] = ibuf[10] ^ ip[10]; obuf[11] = ibuf[11] ^ ip[11];
                obuf[12] = ibuf[12] ^ ip[12]; obuf[13] = ibuf[13] ^ ip[13];
                obuf[14] = ibuf[14] ^ ip[14]; obuf[15] = ibuf[15] ^ ip[15];
                i += AES_BLOCK_SIZE;
                ip += AES_BLOCK_SIZE;
                ibuf += AES_BLOCK_SIZE;
                obuf += AES_BLOCK_SIZE;
            }

        while(i++ < blen)
            *obuf++ = *ibuf++ ^ ip[b_pos++];
    }

    ctx->inf.b[2] = b_pos;
    return EXIT_SUCCESS;
}

#if defined(__cplusplus)
}
#endif
#endif