SHA-2（Secure Hash Algorithm 2）

SHA-2（Secure Hash Algorithm 2）是一组密码学哈希函数，由美国国家安全局（NSA）设计，并由美国国家标准与技术研究院（NIST）发布。SHA-2家族是SHA-1的后继者，弥补了SHA-1在安全性方面的不足。SHA-2在安全性和应用领域方面得到了广泛的认可和使用。

SHA-2 家族成员

SHA-2家族包括多个不同的哈希算法，它们的主要区别在于生成的哈希值长度不同：

1. SHA-224：

   • 生成224位（28字节）的哈希值。
   • 在安全性和性能之间取得了平衡，适用于某些特定场合。

2. SHA-256：

   • 生成256位（32字节）的哈希值。
   • 是SHA-2家族中应用最为广泛的成员，广泛用于数字签名、证书、加密协议（如TLS/SSL）、区块链等领域。

3. SHA-384：

   • 生成384位（48字节）的哈希值。
   • 主要用于需要更高安全性但长度较短的哈希值的场合。

4. SHA-512：

   • 生成512位（64字节）的哈希值。
   • 提供最高的安全性，适用于高安全性要求的场合，如数据完整性验证、密钥生成等。

5. SHA-512/224 和 SHA-512/256：

   • 分别生成224位和256位的哈希值，但基于SHA-512的算法设计，提供了更高的安全性和效率。

SHA-2的特点

• 安全性增强：与SHA-1相比，SHA-2大幅提升了抗碰撞攻击和抗预映像攻击的能力，至今没有已知的有效攻击方法。
• 可扩展性：SHA-2家族提供多种不同长度的哈希值，可以根据具体需求选择合适的算法。
• 广泛应用：SHA-2被广泛应用于数字签名、证书、加密协议、区块链等各种需要数据完整性和安全性的领域。

SHA-2的工作原理

SHA-2家族的哈希函数基于Merkle-Damgård结构，它们的工作原理与SHA-1相似，但在算法复杂度和安全性上进行了改进。以下是SHA-256的简化工作流程：

1. 消息填充：

   • 将输入数据进行填充，使得其长度为512位的倍数。在消息末尾添加一个“1”比特，随后填充若干“0”，最后添加一个64位整数，表示原始消息的长度。

2. 初始化哈希值：

   • 初始化8个32位的状态变量（H0 到 H7），这些初始值是根据分解质数的平方根的小数部分选定的。

3. 处理消息块：

   • 将消息分割成多个512位的块，每个块被分成16个32位的字，并通过扩展生成64个字（SHA-512生成80个字）。
   • 每一轮处理时，利用状态变量和当前消息块中的数据进行复杂的数学运算和位操作，将结果混合到状态变量中。

4. 生成最终哈希值：

   • 所有消息块处理完成后，最终的状态变量被连接起来，生成256位的哈希值。

安全性和应用

• 抗碰撞性：SHA-2家族极大提高了抗碰撞性，没有已知的有效碰撞攻击。
• 广泛使用：SHA-256已成为互联网安全协议中的标准，如TLS、SSL、PGP、SSH、IPsec等，区块链技术如比特币也依赖于SHA-256。
• 后继算法：虽然SHA-2目前被广泛应用，但SHA-3（Keccak算法）已被选为未来的标准，以应对更长远的安全需求。

SHA224的C语言示例

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

typedef struct {
    uint32_t state[8];  // 哈希状态
    uint64_t count;     // 比特计数
    uint8_t buffer[64]; // 输入缓冲区
} SHA224_CTX;

void SHA224_Init(SHA224_CTX *context);
void SHA224_Update(SHA224_CTX *context, const uint8_t *data, size_t len);
void SHA224_Final(uint8_t digest[28], SHA224_CTX *context);
void SHA224_Transform(uint32_t state[8], const uint8_t block[64]);

#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b))))

#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22))
#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25))
#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3))
#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10))

static const uint32_t k[64] = {
        0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
        0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
        0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
        0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
        0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
        0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
        0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
        0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
        0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
        0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
        0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
        0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
        0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
        0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
        0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
        0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

void SHA224_Init(SHA224_CTX *context) {
    context->state[0] = 0xc1059ed8;
    context->state[1] = 0x367cd507;
    context->state[2] = 0x3070dd17;
    context->state[3] = 0xf70e5939;
    context->state[4] = 0xffc00b31;
    context->state[5] = 0x68581511;
    context->state[6] = 0x64f98fa7;
    context->state[7] = 0xbefa4fa4;
    context->count = 0;
}

void SHA224_Update(SHA224_CTX *context, const uint8_t *data, size_t len) {
    size_t i = 0, index = (context->count >> 3) & 0x3F;
    context->count += len << 3;

    size_t partLen = 64 - index;
    if (len >= partLen) {
        memcpy(&context->buffer[index], data, partLen);
        SHA224_Transform(context->state, context->buffer);

        for (i = partLen; i + 63 < len; i += 64) {
            SHA224_Transform(context->state, &data[i]);
        }

        index = 0;
    }

    memcpy(&context->buffer[index], &data[i], len - i);
}

void SHA224_Final(uint8_t digest[28], SHA224_CTX *context) {
    uint8_t bits[8];
    size_t index, padLen;
    static uint8_t padding[64] = { 0x80 };

    for (int i = 0; i < 8; i++) {
        bits[i] = (context->count >> (56 - i * 8)) & 0xFF;
    }

    index = (context->count >> 3) & 0x3F;
    padLen = (index < 56) ? (56 - index) : (120 - index);
    SHA224_Update(context, padding, padLen);
    SHA224_Update(context, bits, 8);

    for (int i = 0; i < 7; i++) {
        digest[i * 4] = (context->state[i] >> 24) & 0xFF;
        digest[i * 4 + 1] = (context->state[i] >> 16) & 0xFF;
        digest[i * 4 + 2] = (context->state[i] >> 8) & 0xFF;
        digest[i * 4 + 3] = context->state[i] & 0xFF;
    }

    memset(context, 0, sizeof(*context));
}

void SHA224_Transform(uint32_t state[8], const uint8_t block[64]) {
    uint32_t a, b, c, d, e, f, g, h, t1, t2, m[64];

    for (int i = 0, j = 0; i < 16; i++, j += 4) {
        m[i] = (block[j] << 24) | (block[j + 1] << 16) | (block[j + 2] << 8) | (block[j + 3]);
    }

    for (int i = 16; i < 64; i++) {
        m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
    }

    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    f = state[5];
    g = state[6];
    h = state[7];

    for (int i = 0; i < 64; i++) {
        t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i];
        t2 = EP0(a) + MAJ(a,b,c);
        h = g;
        g = f;
        f = e;
        e = d + t1;
        d = c;
        c = b;
        b = a;
        a = t1 + t2;
    }

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    state[5] += f;
    state[6] += g;
    state[7] += h;
}

// 打印哈希值
void SHA224_Print(uint8_t digest[28]) {
    for (int i = 0; i < 28; i++) {
        printf("%02x", digest[i]);
    }
    printf("\n");
}

int main() {
    SHA224_CTX context;
    uint8_t digest[28];
    uint8_t *string = (uint8_t *)"hello world";

    SHA224_Init(&context);
    SHA224_Update(&context, string, strlen((char *)string));
    SHA224_Final(digest, &context);

    printf("SHA224(\"%s\") = ", string);
    SHA224_Print(digest);

    return 0;
}

SHA256的C语言示例

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

typedef struct {
    uint32_t state[8];  // 哈希状态
    uint64_t count;     // 比特计数
    uint8_t buffer[64]; // 输入缓冲区
} SHA256_CTX;

void SHA256_Init(SHA256_CTX *context);
void SHA256_Update(SHA256_CTX *context, const uint8_t *data, size_t len);
void SHA256_Final(uint8_t digest[32], SHA256_CTX *context);
void SHA256_Transform(uint32_t state[8], const uint8_t block[64]);

#define ROTRIGHT(a,b) (((a) >> (b)) | ((a) << (32-(b))))

#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define EP0(x) (ROTRIGHT(x,2) ^ ROTRIGHT(x,13) ^ ROTRIGHT(x,22))
#define EP1(x) (ROTRIGHT(x,6) ^ ROTRIGHT(x,11) ^ ROTRIGHT(x,25))
#define SIG0(x) (ROTRIGHT(x,7) ^ ROTRIGHT(x,18) ^ ((x) >> 3))
#define SIG1(x) (ROTRIGHT(x,17) ^ ROTRIGHT(x,19) ^ ((x) >> 10))

static const uint32_t k[64] = {
        0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
        0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
        0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
        0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
        0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
        0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
        0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
        0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
        0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
        0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
        0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
        0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
        0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
        0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
        0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
        0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

void SHA256_Init(SHA256_CTX *context) {
    context->state[0] = 0x6a09e667;
    context->state[1] = 0xbb67ae85;
    context->state[2] = 0x3c6ef372;
    context->state[3] = 0xa54ff53a;
    context->state[4] = 0x510e527f;
    context->state[5] = 0x9b05688c;
    context->state[6] = 0x1f83d9ab;
    context->state[7] = 0x5be0cd19;
    context->count = 0;
}

void SHA256_Update(SHA256_CTX *context, const uint8_t *data, size_t len) {
    size_t i = 0, index = (context->count >> 3) & 0x3F;
    context->count += len << 3;

    size_t partLen = 64 - index;
    if (len >= partLen) {
        memcpy(&context->buffer[index], data, partLen);
        SHA256_Transform(context->state, context->buffer);

        for (i = partLen; i + 63 < len; i += 64) {
            SHA256_Transform(context->state, &data[i]);
        }

        index = 0;
    }

    memcpy(&context->buffer[index], &data[i], len - i);
}

void SHA256_Final(uint8_t digest[32], SHA256_CTX *context) {
    uint8_t bits[8];
    size_t index, padLen;
    static uint8_t padding[64] = { 0x80 };

    for (int i = 0; i < 8; i++) {
        bits[i] = (context->count >> (56 - i * 8)) & 0xFF;
    }

    index = (context->count >> 3) & 0x3F;
    padLen = (index < 56) ? (56 - index) : (120 - index);
    SHA256_Update(context, padding, padLen);
    SHA256_Update(context, bits, 8);

    for (int i = 0; i < 8; i++) {
        digest[i * 4] = (context->state[i] >> 24) & 0xFF;
        digest[i * 4 + 1] = (context->state[i] >> 16) & 0xFF;
        digest[i * 4 + 2] = (context->state[i] >> 8) & 0xFF;
        digest[i * 4 + 3] = context->state[i] & 0xFF;
    }

    memset(context, 0, sizeof(*context));
}

void SHA256_Transform(uint32_t state[8], const uint8_t block[64]) {
    uint32_t a, b, c, d, e, f, g, h, t1, t2, m[64];

    for (int i = 0, j = 0; i < 16; i++, j += 4) {
        m[i] = (block[j] << 24) | (block[j + 1] << 16) | (block[j + 2] << 8) | (block[j + 3]);
    }

    for (int i = 16; i < 64; i++) {
        m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
    }

    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    f = state[5];
    g = state[6];
    h = state[7];

    for (int i = 0; i < 64; i++) {
        t1 = h + EP1(e) + CH(e,f,g) + k[i] + m[i];
        t2 = EP0(a) + MAJ(a,b,c);
        h = g;
        g = f;
        f = e;
        e = d + t1;
        d = c;
        c = b;
        b = a;
        a = t1 + t2;
    }

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    state[5] += f;
    state[6] += g;
    state[7] += h;
}

// 打印哈希值
void SHA256_Print(uint8_t digest[32]) {
    for (int i = 0; i < 32; i++) {
        printf("%02x", digest[i]);
    }
    printf("\n");
}

int main() {
    SHA256_CTX context;
    uint8_t digest[32];
    uint8_t *string = (uint8_t *)"hello world";

    SHA256_Init(&context);
    SHA256_Update(&context, string, strlen((char *)string));
    SHA256_Final(digest, &context);

    printf("SHA256(\"%s\") = ", string);
    SHA256_Print(digest);

    return 0;
}

SHA384的C语言示例

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

typedef struct {
    uint64_t state[8];  // 哈希状态
    uint64_t count[2];  // 比特计数
    uint8_t buffer[128]; // 输入缓冲区
} SHA384_CTX;

void SHA384_Init(SHA384_CTX *context);
void SHA384_Update(SHA384_CTX *context, const uint8_t *data, size_t len);
void SHA384_Final(uint8_t digest[48], SHA384_CTX *context);
void SHA384_Transform(uint64_t state[8], const uint8_t block[128]);

#define ROTR64(x, n) (((x) >> (n)) | ((x) << (64 - (n))))

#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define EP0(x) (ROTR64(x,28) ^ ROTR64(x,34) ^ ROTR64(x,39))
#define EP1(x) (ROTR64(x,14) ^ ROTR64(x,18) ^ ROTR64(x,41))
#define SIG0(x) (ROTR64(x,1) ^ ROTR64(x,8) ^ ((x) >> 7))
#define SIG1(x) (ROTR64(x,19) ^ ROTR64(x,61) ^ ((x) >> 6))

static const uint64_t k[80] = {
        0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
        0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
        0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
        0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
        0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
        0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
        0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
        0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
        0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
        0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
        0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
        0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
        0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
        0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
        0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
        0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
        0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
        0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
        0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
        0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817
};

void SHA384_Init(SHA384_CTX *context) {
    context->state[0] = 0xcbbb9d5dc1059ed8;
    context->state[1] = 0x629a292a367cd507;
    context->state[2] = 0x9159015a3070dd17;
    context->state[3] = 0x152fecd8f70e5939;
    context->state[4] = 0x67332667ffc00b31;
    context->state[5] = 0x8eb44a8768581511;
    context->state[6] = 0xdb0c2e0d64f98fa7;
    context->state[7] = 0x47b5481dbefa4fa4;
    context->count[0] = context->count[1] = 0;
}

void SHA384_Update(SHA384_CTX *context, const uint8_t *data, size_t len) {
    size_t i = 0, index = (context->count[0] >> 3) & 0x7F;
    context->count[0] += len << 3;

    if (context->count[0] < (len << 3)) {
        context->count[1]++;
    }
    context->count[1] += (len >> 61);

    size_t partLen = 128 - index;
    if (len >= partLen) {
        memcpy(&context->buffer[index], data, partLen);
        SHA384_Transform(context->state, context->buffer);

        for (i = partLen; i + 127 < len; i += 128) {
            SHA384_Transform(context->state, &data[i]);
        }

        index = 0;
    }

    memcpy(&context->buffer[index], &data[i], len - i);
}

void SHA384_Final(uint8_t digest[48], SHA384_CTX *context) {
    uint8_t bits[16];
    size_t index, padLen;
    static uint8_t padding[128] = { 0x80 };

    for (int i = 0; i < 8; i++) {
        bits[i] = (context->count[1] >> (56 - i * 8)) & 0xFF;
        bits[i + 8] = (context->count[0] >> (56 - i * 8)) & 0xFF;
    }

    index = (context->count[0] >> 3) & 0x7F;
    padLen = (index < 112) ? (112 - index) : (240 - index);
    SHA384_Update(context, padding, padLen);
    SHA384_Update(context, bits, 16);

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

    memset(context, 0, sizeof(*context));
}

void SHA384_Transform(uint64_t state[8], const uint8_t block[128]) {
    uint64_t a, b, c, d, e, f, g, h, t1, t2, m[80];

    for (int i = 0, j = 0; i < 16; i++, j += 8) {
        m[i] = ((uint64_t)block[j] << 56) | ((uint64_t)block[j + 1] << 48) |
               ((uint64_t)block[j + 2] << 40) | ((uint64_t)block[j + 3] << 32) |
               ((uint64_t)block[j + 4] << 24) | ((uint64_t)block[j + 5] << 16) |
               ((uint64_t)block[j + 6] << 8) | ((uint64_t)block[j + 7]);
    }

    for (int i = 16; i < 80; i++) {
        m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
    }

    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    f = state[5];
    g = state[6];
    h = state[7];

    for (int i = 0; i < 80; i++) {
        t1 = h + EP1(e) + CH(e, f, g) + k[i] + m[i];
        t2 = EP0(a) + MAJ(a, b, c);
        h = g;
        g = f;
        f = e;
        e = d + t1;
        d = c;
        c = b;
        b = a;
        a = t1 + t2;
    }

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    state[5] += f;
    state[6] += g;
    state[7] += h;
}

// 打印哈希值
void SHA384_Print(uint8_t digest[48]) {
    for (int i = 0; i < 48; i++) {
        printf("%02x", digest[i]);
    }
    printf("\n");
}

int main() {
    SHA384_CTX context;
    uint8_t digest[48];
    uint8_t *string = (uint8_t *)"hello world";

    SHA384_Init(&context);
    SHA384_Update(&context, string, strlen((char *)string));
    SHA384_Final(digest, &context);

    printf("SHA384(\"%s\") = ", string);
    SHA384_Print(digest);

    return 0;
}

SHA512的C语言示例

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

typedef struct {
    uint64_t state[8];  // 哈希状态
    uint64_t count[2];  // 比特计数
    uint8_t buffer[128]; // 输入缓冲区
} SHA512_CTX;

void SHA512_Init(SHA512_CTX *context);
void SHA512_Update(SHA512_CTX *context, const uint8_t *data, size_t len);
void SHA512_Final(uint8_t digest[64], SHA512_CTX *context);
void SHA512_Transform(uint64_t state[8], const uint8_t block[128]);

#define ROTR64(x, n) (((x) >> (n)) | ((x) << (64 - (n))))

#define CH(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
#define MAJ(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define EP0(x) (ROTR64(x,28) ^ ROTR64(x,34) ^ ROTR64(x,39))
#define EP1(x) (ROTR64(x,14) ^ ROTR64(x,18) ^ ROTR64(x,41))
#define SIG0(x) (ROTR64(x,1) ^ ROTR64(x,8) ^ ((x) >> 7))
#define SIG1(x) (ROTR64(x,19) ^ ROTR64(x,61) ^ ((x) >> 6))

static const uint64_t k[80] = {
        0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
        0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118,
        0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
        0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
        0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65,
        0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
        0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
        0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
        0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
        0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
        0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30,
        0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
        0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
        0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3,
        0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
        0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
        0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
        0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
        0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
        0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817
};

void SHA512_Init(SHA512_CTX *context) {
    context->state[0] = 0x6a09e667f3bcc908;
    context->state[1] = 0xbb67ae8584caa73b;
    context->state[2] = 0x3c6ef372fe94f82b;
    context->state[3] = 0xa54ff53a5f1d36f1;
    context->state[4] = 0x510e527fade682d1;
    context->state[5] = 0x9b05688c2b3e6c1f;
    context->state[6] = 0x1f83d9abfb41bd6b;
    context->state[7] = 0x5be0cd19137e2179;
    context->count[0] = context->count[1] = 0;
}

void SHA512_Update(SHA512_CTX *context, const uint8_t *data, size_t len) {
    size_t i = 0, index = (context->count[0] >> 3) & 0x7F;
    context->count[0] += len << 3;

    if (context->count[0] < (len << 3)) {
        context->count[1]++;
    }
    context->count[1] += (len >> 61);

    size_t partLen = 128 - index;
    if (len >= partLen) {
        memcpy(&context->buffer[index], data, partLen);
        SHA512_Transform(context->state, context->buffer);

        for (i = partLen; i + 127 < len; i += 128) {
            SHA512_Transform(context->state, &data[i]);
        }

        index = 0;
    }

    memcpy(&context->buffer[index], &data[i], len - i);
}

void SHA512_Final(uint8_t digest[64], SHA512_CTX *context) {
    uint8_t bits[16];
    size_t index, padLen;
    static uint8_t padding[128] = { 0x80 };

    for (int i = 0; i < 8; i++) {
        bits[i] = (context->count[1] >> (56 - i * 8)) & 0xFF;
        bits[i + 8] = (context->count[0] >> (56 - i * 8)) & 0xFF;
    }

    index = (context->count[0] >> 3) & 0x7F;
    padLen = (index < 112) ? (112 - index) : (240 - index);
    SHA512_Update(context, padding, padLen);
    SHA512_Update(context, bits, 16);

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

    memset(context, 0, sizeof(*context));
}

void SHA512_Transform(uint64_t state[8], const uint8_t block[128]) {
    uint64_t a, b, c, d, e, f, g, h, t1, t2, m[80];

    for (int i = 0, j = 0; i < 16; i++, j += 8) {
        m[i] = ((uint64_t)block[j] << 56) | ((uint64_t)block[j + 1] << 48) |
               ((uint64_t)block[j + 2] << 40) | ((uint64_t)block[j + 3] << 32) |
               ((uint64_t)block[j + 4] << 24) | ((uint64_t)block[j + 5] << 16) |
               ((uint64_t)block[j + 6] << 8) | ((uint64_t)block[j + 7]);
    }

    for (int i = 16; i < 80; i++) {
        m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];
    }

    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    f = state[5];
    g = state[6];
    h = state[7];

    for (int i = 0; i < 80; i++) {
        t1 = h + EP1(e) + CH(e, f, g) + k[i] + m[i];
        t2 = EP0(a) + MAJ(a, b, c);
        h = g;
        g = f;
        f = e;
        e = d + t1;
        d = c;
        c = b;
        b = a;
        a = t1 + t2;
    }

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;
    state[5] += f;
    state[6] += g;
    state[7] += h;
}

// 打印哈希值
void SHA512_Print(uint8_t digest[64]) {
    for (int i = 0; i < 64; i++) {
        printf("%02x", digest[i]);
    }
    printf("\n");
}

int main() {
    SHA512_CTX context;
    uint8_t digest[64];
    uint8_t *string = (uint8_t *)"hello world";

    SHA512_Init(&context);
    SHA512_Update(&context, string, strlen((char *)string));
    SHA512_Final(digest, &context);

    printf("SHA512(\"%s\") = ", string);
    SHA512_Print(digest);

    return 0;
}