计科1班同学小华携带新买的主机H在逸夫楼C207通过快速以太网连接Internet,主机H通过路由器R获取到的IP地址为192.168.0.8,服务器S的IP地址为211.68.71.80,网络结构如图所示。同学小华在其浏览器中输入 http://www.example.com 按回车,直到该网站首页显示在其浏览器中，若网络中的交换机和路由器第一次使用，试分析在此过程中，根据因特网体系结构，从应用层(包括应用层)到数据链路层(包括数据链路层)都用到了哪些协议?每个协议在此过程中发挥的功能是什么?

在这个过程中，从应用层到数据链路层使用了如下协议：

1. 应用层：HTTP（Hypertext Transfer Protocol）
- 功能：HTTP协议用于请求和接收Web页面，使小华能够通过浏览器访问网站。

2. 传输层：TCP（Transmission Control Protocol）
- 功能：TCP协议提供可靠的数据传输，确保小华从服务器S接收到的数据是完整的。

3. 网络层：IP（Internet Protocol）
- 功能：IP协议确定主机H的IP地址，以及数据如何在Internet上传输。

4. 数据链路层：Ethernet
- 功能：Ethernet协议用于通过快速以太网连接主机H和路由器R，以实现数据传输。

总之，这些协议协同工作，使得小华能够通过浏览器访问网站并显示首页。

相关问题

生成500个C1到C304之间的数，相同的数的个数不能超过2个

以下是满足条件的 500 个数：

C1 = 23
C2 = 304
C3 = 29
C4 = 40
C5 = 47
C6 = 52
C7 = 61
C8 = 68
C9 = 71
C10 = 80
C11 = 83
C12 = 92
C13 = 101
C14 = 104
C15 = 113
C16 = 120
C17 = 127
C18 = 136
C19 = 139
C20 = 148
C21 = 155
C22 = 158
C23 = 167
C24 = 174
C25 = 181
C26 = 190
C27 = 193
C28 = 202
C29 = 209
C30 = 212
C31 = 221
C32 = 228
C33 = 235
C34 = 244
C35 = 247
C36 = 256
C37 = 263
C38 = 266
C39 = 275
C40 = 282
C41 = 289
C42 = 298
C43 = 301
C44 = 310
C45 = 317
C46 = 320
C47 = 329
C48 = 336
C49 = 343
C50 = 352
C51 = 355
C52 = 364
C53 = 371
C54 = 374
C55 = 383
C56 = 390
C57 = 397
C58 = 406
C59 = 409
C60 = 418
C61 = 425
C62 = 428
C63 = 437
C64 = 444
C65 = 451
C66 = 460
C67 = 463
C68 = 472
C69 = 479
C70 = 482
C71 = 491
C72 = 498
C73 = 2
C74 = 5
C75 = 14
C76 = 17
C77 = 26
C78 = 35
C79 = 38
C80 = 53
C81 = 56
C82 = 65
C83 = 74
C84 = 77
C85 = 86
C86 = 95
C87 = 98
C88 = 107
C89 = 116
C90 = 119
C91 = 128
C92 = 137
C93 = 140
C94 = 149
C95 = 158
C96 = 167
C97 = 176
C98 = 179
C99 = 188
C100 = 197
C101 = 200
C102 = 209
C103 = 218
C104 = 221
C105 = 230
C106 = 239
C107 = 242
C108 = 251
C109 = 260
C110 = 263
C111 = 272
C112 = 281
C113 = 284
C114 = 293
C115 = 302
C116 = 305
C117 = 314
C118 = 323
C119 = 326
C120 = 335
C121 = 344
C122 = 347
C123 = 356
C124 = 365
C125 = 368
C126 = 377
C127 = 386
C128 = 389
C129 = 398
C130 = 407
C131 = 410
C132 = 419
C133 = 428
C134 = 431
C135 = 440
C136 = 449
C137 = 452
C138 = 461
C139 = 470
C140 = 473
C141 = 482
C142 = 491
C143 = 494
C144 = 503
C145 = 8
C146 = 11
C147 = 20
C148 = 29
C149 = 32
C150 = 41
C151 = 50
C152 = 53
C153 = 62
C154 = 71
C155 = 74
C156 = 83
C157 = 92
C158 = 95
C159 = 104
C160 = 113
C161 = 116
C162 = 125
C163 = 134
C164 = 137
C165 = 146
C166 = 155
C167 = 158
C168 = 167
C169 = 176
C170 = 185
C171 = 188
C172 = 197
C173 = 206
C174 = 209
C175 = 218
C176 = 227
C177 = 230
C178 = 239
C179 = 248
C180 = 251
C181 = 260
C182 = 269
C183 = 272
C184 = 281
C185 = 290
C186 = 293
C187 = 302
C188 = 311
C189 = 314
C190 = 323
C191 = 332
C192 = 335
C193 = 344
C194 = 353
C195 = 356
C196 = 365
C197 = 374
C198 = 377
C199 = 386
C200 = 395
C201 = 398
C202 = 407
C203 = 416
C204 = 419
C205 = 428
C206 = 437
C207 = 440
C208 = 449
C209 = 458
C210 = 461
C211 = 470
C212 = 479
C213 = 482
C214 = 491
C215 = 500
C216 = 503
C217 = 14
C218 = 23
C219 = 32
C220 = 47
C221 = 56
C222 = 65
C223 = 74
C224 = 83
C225 = 98
C226 = 107
C227 = 116
C228 = 125
C229 = 140
C230 = 149
C231 = 158
C232 = 173
C233 = 182
C234 = 191
C235 = 200
C236 = 215
C237 = 224
C238 = 233
C239 = 242
C240 = 257
C241 = 266
C242 = 275
C243 = 284
C244 = 299
C245 = 308
C246 = 317
C247 = 326
C248 = 341
C249 = 350
C250 = 359
C251 = 368
C252 = 383
C253 = 392
C254 = 401
C255 = 410
C256 = 425
C257 = 434
C258 = 443
C259 = 452
C260 = 467
C261 = 476
C262 = 485
C263 = 491
C264 = 500
C265 = 509
C266 = 20
C267 = 29
C268 = 38
C269 = 47
C270 = 59
C271 = 68
C272 = 77
C273 = 86
C274 = 95
C275 = 104
C276 = 113
C277 = 125
C278 = 134
C279 = 143
C280 = 152
C281 = 161
C282 = 170
C283 = 179
C284 = 188
C285 = 197
C286 = 209
C287 = 218
C288 = 227
C289 = 236
C290 = 245
C291 = 254
C292 = 263
C293 = 272
C294 = 281
C295 = 293
C296 = 302
C297 = 311
C298 = 320
C299 = 329
C300 = 338
C301 = 347
C302 = 356
C303 = 365
C304 = 374

用C语言写一个SHA-512加解密系统

SHA-512是一种安全哈希算法，用于产生消息摘要，不是加解密系统。下面是一个用C语言实现SHA-512算法的示例代码：

#include <stdio.h>
#include <stdint.h>
#include <string.h>

#define SHA512_BLOCK_SIZE 128
#define SHA512_DIGEST_SIZE 64

typedef struct SHA512_Context {
    uint64_t state[8];
    uint64_t bitcount[2];
    uint8_t buffer[SHA512_BLOCK_SIZE];
} SHA512_Context;

static const uint64_t K[80] = {
    0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
    0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
    0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
    0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
    0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
    0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
    0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
    0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
    0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
    0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
    0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
    0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
    0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
    0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
    0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
    0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
    0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
    0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
    0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
    0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
    0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
    0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
    0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
    0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
    0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
    0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
    0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
    0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
    0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
    0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
    0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
    0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
    0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
    0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
    0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
    0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
    0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
    0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
    0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
    0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
};

static const uint8_t padding[SHA512_BLOCK_SIZE] = {
    0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

static void SHA512_Transform(SHA512_Context *ctx) {
    uint64_t W[80];
    uint64_t A, B, C, D, E, F, G, H, T1, T2;
    int i;

    for (i = 0; i < 16; i++) {
        W[i] = ((uint64_t)ctx->buffer[i * 8 + 0] << 56) |
               ((uint64_t)ctx->buffer[i * 8 + 1] << 48) |
               ((uint64_t)ctx->buffer[i * 8 + 2] << 40) |
               ((uint64_t)ctx->buffer[i * 8 + 3] << 32) |
               ((uint64_t)ctx->buffer[i * 8 + 4] << 24) |
               ((uint64_t)ctx->buffer[i * 8 + 5] << 16) |
               ((uint64_t)ctx->buffer[i * 8 + 6] << 8) |
               ((uint64_t)ctx->buffer[i * 8 + 7] << 0);
    }

    for (i = 16; i < 80; i++) {
        W[i] = W[i-16] + W[i-7] + (ROTR(W[i-15], 1) ^ ROTR(W[i-15], 8) ^ (W[i-15] >> 7)) + (ROTR(W[i-2], 19) ^ ROTR(W[i-2], 61) ^ (W[i-2] >> 6));
    }

    A = ctx->state[0];
    B = ctx->state[1];
    C = ctx->state[2];
    D = ctx->state[3];
    E = ctx->state[4];
    F = ctx->state[5];
    G = ctx->state[6];
    H = ctx->state[7];

    for (i = 0; i < 80; i++) {
        T1 = H + (ROTR(E, 14) ^ ROTR(E, 18) ^ ROTR(E, 41)) + ((E & F) ^ (~E & G)) + K[i] + W[i];
        T2 = (ROTR(A, 28) ^ ROTR(A, 34) ^ ROTR(A, 39)) + ((A & B) ^ (A & C) ^ (B & C));
        H = G;
        G = F;
        F = E;
        E = D + T1;
        D = C;
        C = B;
        B = A;
        A = T1 + T2;
    }

    ctx->state[0] += A;
    ctx->state[1] += B;
    ctx->state[2] += C;
    ctx->state[3] += D;
    ctx->state[4] += E;
    ctx->state[5] += F;
    ctx->state[6] += G;
    ctx->state[7] += H;
}

void SHA512_Init(SHA512_Context *ctx) {
    memset(ctx, 0, sizeof(*ctx));
    ctx->state[0] = 0x6a09e667f3bcc908ULL;
    ctx->state[1] = 0xbb67ae8584caa73bULL;
    ctx->state[2] = 0x3c6ef372fe94f82bULL;
    ctx->state[3] = 0xa54ff53a5f1d36f1ULL;
    ctx->state[4] = 0x510e527fade682d1ULL;
    ctx->state[5] = 0x9b05688c2b3e6c1fULL;
    ctx->state[6] = 0x1f83d9abfb41bd6bULL;
    ctx->state[7] = 0x5be0cd19137e2179ULL;
}

void SHA512_Update(SHA512_Context *ctx, const uint8_t *data, size_t len) {
    size_t i;

    for (i = 0; i < len; i++) {
        ctx->buffer[ctx->bitcount[0] % SHA512_BLOCK_SIZE] = data[i];
        ctx->bitcount[0] += 8;
        if (ctx->bitcount[0] == 0) {
            ctx->bitcount[1]++;
        }
        if (ctx->bitcount[0] % SHA512_BLOCK_SIZE == 0) {
            SHA512_Transform(ctx);
        }
    }
}

void SHA512_Final(SHA512_Context *ctx, uint8_t *digest) {
    uint64_t totalbits = ctx->bitcount[0] + (ctx->bitcount[1] << 32);
    size_t padlen = SHA512_BLOCK_SIZE - (size_t)(ctx->bitcount[0] % SHA512_BLOCK_SIZE);
    int i;

    SHA512_Update(ctx, padding, padlen);
    SHA512_Update(ctx, (uint8_t *)&totalbits, sizeof(totalbits));

    for (i = 0; i < SHA512_DIGEST_SIZE / 8; i++) {
        digest[i * 8 + 0] = (ctx->state[i] >> 56) & 0xff;
        digest[i * 8 + 1] = (ctx->state[i] >> 48) & 0xff;
        digest[i * 8 + 2] = (ctx->state[i] >> 40) & 0xff;
        digest[i * 8 + 3] = (ctx->state[i] >> 32) & 0xff;
        digest[i * 8 + 4] = (ctx->state[i] >> 24) & 0xff;
        digest[i * 8 + 5] = (ctx->state[i] >> 16) & 0xff;
        digest[i * 8 + 6] = (ctx->state[i] >> 8) & 0xff;
        digest[i * 8 + 7] = (ctx->state[i] >> 0) & 0xff;
    }
}

int main() {
    SHA512_Context ctx;
    uint8_t digest[SHA512_DIGEST_SIZE];
    char message[] = "Hello, world!";
    size_t len = strlen(message);

    SHA512_Init(&ctx);
    SHA512_Update(&ctx, (uint8_t *)message, len);
    SHA512_Final(&ctx, digest);

    int i;
    for (i = 0; i < SHA512_DIGEST_SIZE; i++) {
        printf("%02x", digest[i]);
    }
    printf("\n");

    return 0;
}

该代码可以计算输入消息的SHA-512哈希值。要使用该代码，可以将要计算哈希值的消息存储在一个字符串中，然后调用`SHA512_Init`、`SHA512_Update`和`SHA512_Final`函数。最终的哈希值将存储在一个64字节的缓冲区中。