int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)
{
    PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
    int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
                                                (diff > (0 - (PTRDIFF_T)len)));
    return overlapped;
}
['static int enc_read(BIO *b, char *out, int outl)\n{\n    int ret = 0, i, blocksize;\n    BIO_ENC_CTX *ctx;\n    BIO *next;\n    if (out == NULL)\n        return (0);\n    ctx = BIO_get_data(b);\n    next = BIO_next(b);\n    if ((ctx == NULL) || (next == NULL))\n        return 0;\n    if (ctx->buf_len > 0) {\n        i = ctx->buf_len - ctx->buf_off;\n        if (i > outl)\n            i = outl;\n        memcpy(out, &(ctx->buf[ctx->buf_off]), i);\n        ret = i;\n        out += i;\n        outl -= i;\n        ctx->buf_off += i;\n        if (ctx->buf_len == ctx->buf_off) {\n            ctx->buf_len = 0;\n            ctx->buf_off = 0;\n        }\n    }\n    blocksize = EVP_CIPHER_CTX_block_size(ctx->cipher);\n    if (blocksize == 1)\n        blocksize = 0;\n    while (outl > 0) {\n        if (ctx->cont <= 0)\n            break;\n        if (ctx->read_start == ctx->read_end) {\n            ctx->read_end = ctx->read_start = &(ctx->buf[BUF_OFFSET]);\n            i = BIO_read(next, ctx->read_start, ENC_BLOCK_SIZE);\n            if (i > 0)\n                ctx->read_end += i;\n        } else {\n            i = ctx->read_end - ctx->read_start;\n        }\n        if (i <= 0) {\n            if (!BIO_should_retry(next)) {\n                ctx->cont = i;\n                i = EVP_CipherFinal_ex(ctx->cipher,\n                                       ctx->buf, &(ctx->buf_len));\n                ctx->ok = i;\n                ctx->buf_off = 0;\n            } else {\n                ret = (ret == 0) ? i : ret;\n                break;\n            }\n        } else {\n            if (outl > ENC_MIN_CHUNK) {\n                int j = outl - blocksize, buf_len;\n                if (!EVP_CipherUpdate(ctx->cipher,\n                                      (unsigned char *)out, &buf_len,\n                                      ctx->read_start, i > j ? j : i)) {\n                    BIO_clear_retry_flags(b);\n                    return 0;\n                }\n                ret += buf_len;\n                out += buf_len;\n                outl -= buf_len;\n                if ((i -= j) <= 0) {\n                    ctx->read_start = ctx->read_end;\n                    continue;\n                }\n                ctx->read_start += j;\n            }\n            if (i > ENC_MIN_CHUNK)\n                i = ENC_MIN_CHUNK;\n            if (!EVP_CipherUpdate(ctx->cipher,\n                                  ctx->buf, &ctx->buf_len,\n                                  ctx->read_start, i)) {\n                BIO_clear_retry_flags(b);\n                ctx->ok = 0;\n                return 0;\n            }\n            ctx->read_start += i;\n            ctx->cont = 1;\n            if (ctx->buf_len == 0)\n                continue;\n        }\n        if (ctx->buf_len <= outl)\n            i = ctx->buf_len;\n        else\n            i = outl;\n        if (i <= 0)\n            break;\n        memcpy(out, ctx->buf, i);\n        ret += i;\n        ctx->buf_off = i;\n        outl -= i;\n        out += i;\n    }\n    BIO_clear_retry_flags(b);\n    BIO_copy_next_retry(b);\n    return ((ret == 0) ? ctx->cont : ret);\n}', 'int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,\n                     const unsigned char *in, int inl)\n{\n    if (ctx->encrypt)\n        return EVP_EncryptUpdate(ctx, out, outl, in, inl);\n    else\n        return EVP_DecryptUpdate(ctx, out, outl, in, inl);\n}', 'int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,\n                      const unsigned char *in, int inl)\n{\n    int fix_len;\n    unsigned int b;\n    b = ctx->cipher->block_size;\n    if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {\n        if (b == 1 && is_partially_overlapping(out, in, inl)) {\n            EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);\n            return 0;\n        }\n        fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);\n        if (fix_len < 0) {\n            *outl = 0;\n            return 0;\n        } else\n            *outl = fix_len;\n        return 1;\n    }\n    if (inl <= 0) {\n        *outl = 0;\n        return inl == 0;\n    }\n    if (ctx->flags & EVP_CIPH_NO_PADDING)\n        return EVP_EncryptUpdate(ctx, out, outl, in, inl);\n    OPENSSL_assert(b <= sizeof ctx->final);\n    if (ctx->final_used) {\n        if (((PTRDIFF_T)out == (PTRDIFF_T)in)\n            || is_partially_overlapping(out, in, b)) {\n            EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);\n            return 0;\n        }\n        memcpy(out, ctx->final, b);\n        out += b;\n        fix_len = 1;\n    } else\n        fix_len = 0;\n    if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))\n        return 0;\n    if (b > 1 && !ctx->buf_len) {\n        *outl -= b;\n        ctx->final_used = 1;\n        memcpy(ctx->final, &out[*outl], b);\n    } else\n        ctx->final_used = 0;\n    if (fix_len)\n        *outl += b;\n    return 1;\n}', 'int is_partially_overlapping(const void *ptr1, const void *ptr2, int len)\n{\n    PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;\n    int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |\n                                                (diff > (0 - (PTRDIFF_T)len)));\n    return overlapped;\n}']