TLS-PRF实现示例

#include 
#include 
#include 
#include 
#include 
#include 
#include 

void hmac_sha1(unsigned char *key, int key_len, unsigned char *text, int text_len, unsigned char *digest)
{
    int i;
    unsigned char k_ipad[64];
    unsigned char k_opad[64];
    unsigned char tk[20];

    SHA_CTX ctx;

    if (key_len > 64)
    {
        SHA1(key, key_len, tk);

        SHA1(key, key_len, tk);
        key = tk;
        key_len = 20;
    }

    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    for (i=0; i<64; i++)
    {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    SHA1_Init(&ctx);
    SHA1_Update(&ctx, k_ipad, 64);
    SHA1_Update(&ctx, text, text_len); 
    SHA1_Final(digest, &ctx);         

    SHA1_Init(&ctx);
    SHA1_Update(&ctx, k_opad, 64);
    SHA1_Update(&ctx, digest, 20);
    SHA1_Final(digest, &ctx);
}

void hmac_md5(unsigned char *key, int key_len, unsigned char *text, int text_len, unsigned char *digest)
{
    int i;
    unsigned char k_ipad[64];
    unsigned char k_opad[64];
    unsigned char tk[16];

    MD5_CTX ctx;

    if (key_len > 64)
    {
        MD5(key, key_len, tk);

        key = tk;
        key_len = 16;
    }

    memset(k_ipad, 0, sizeof(k_ipad));
    memset(k_opad, 0, sizeof(k_opad));
    memcpy(k_ipad, key, key_len);
    memcpy(k_opad, key, key_len);

    for (i=0; i<64; i++)
    {
        k_ipad[i] ^= 0x36;
        k_opad[i] ^= 0x5c;
    }

    MD5_Init(&ctx);
    MD5_Update(&ctx, k_ipad, 64);
    MD5_Update(&ctx, text, text_len); 
    MD5_Final(digest, &ctx);         

    MD5_Init(&ctx);
    MD5_Update(&ctx, k_opad, 64);
    MD5_Update(&ctx, digest, 16);
    MD5_Final(digest, &ctx);
}

int p_sha1(unsigned char *secret, int secret_len, unsigned char *seed, int seed_len, unsigned char *out, unsigned int outlen)
{
    int loop = 0;
    int count = (outlen+20-1)/20;
    unsigned char a[20] = {0};
    unsigned char *a_seed = NULL;
    unsigned char hmac_hash[20] = {0};

    if(count <= 0)
        return -1;

    a_seed = (unsigned char*)malloc(20+seed_len);
    if(!a_seed)
        return -1;
    memset(a_seed, 0, 20+seed_len);

    for(loop=0; loopA(1);
        else
            hmac_sha1(secret, secret_len, a, 20, a);            //A(i)->A(i+1);

        memcpy(a_seed, a, 20);
        memcpy(a_seed+20, seed, seed_len);

        hmac_sha1(secret, secret_len, a_seed, 20+seed_len, hmac_hash);
        memcpy(out+loop*20, hmac_hash, 20 < outlen-loop*20 ? 20 : outlen-loop*20);
    }

    if(a_seed) free(a_seed);
    return count;
}

int p_md5(unsigned char *secret, int secret_len, unsigned char *seed, int seed_len, unsigned char *out, unsigned int outlen)
{
    int loop = 0;
    int count = (outlen+16-1)/16;
    unsigned char a[16] = {0};
    unsigned char *a_seed = NULL;
    unsigned char hmac_hash[16] = {0};

    if(count <= 0)
        return -1;

    a_seed = (unsigned char*)malloc(16+seed_len);
    if(!a_seed)
        return -1;
    memset(a_seed, 0, 16+seed_len);

    for(loop=0; loopA(1);
        else
            hmac_md5(secret, secret_len, a, 16, a);             //A(i)->A(i+1);

        memcpy(a_seed, a, 16);
        memcpy(a_seed+16, seed, seed_len);

        hmac_md5(secret, secret_len, a_seed, 16+seed_len, hmac_hash);
        memcpy(out+loop*16, hmac_hash, 16 < outlen-loop*16 ? 16 : outlen-loop*16);
    }

    if(a_seed) free(a_seed);
    return count;
}

int tls_prf(unsigned char *secret, int secret_len, unsigned char *label, int label_len, unsigned char *seed, int seed_len, unsigned char *out, unsigned int outlen)
{
    int ret = 0;
    int loop = 0;
    unsigned char *out_sha1 = NULL;
    unsigned char *out_md5 = NULL;
    unsigned char *label_seed = NULL;

    out_sha1 = (unsigned char*)malloc(outlen);
    if(!out_sha1)
        goto EndP;
    memset(out_sha1, 0, outlen);
    out_md5 = (unsigned char*)malloc(outlen);
    if(!out_md5)
        goto EndP;
    memset(out_md5, 0, outlen);

    label_seed = (unsigned char*)malloc(label_len+seed_len);
    if(!label_seed)
        goto EndP;
    memset(label_seed, 0, label_len+seed_len);

    memcpy(label_seed, label, label_len);
    memcpy(label_seed+label_len, seed, seed_len);
    ret = p_sha1(secret, (secret_len+1)/2, label_seed, label_len+seed_len, out_sha1, outlen);
    if(ret == -1)
        goto EndP;
    ret = p_md5(secret+secret_len/2, (secret_len+1)/2, label_seed, label_len+seed_len, out_md5, outlen);
    if(ret == -1)
        goto EndP;  

    for(loop=0; loop