Module: MTProto::Crypto::AES_IGE

Defined in:
ext/aes_ige/aes_ige.c

Class Method Summary collapse

Class Method Details

.decrypt_ige(ciphertext, key, iv) ⇒ Object 



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# File 'ext/aes_ige/aes_ige.c', line 52

static VALUE
aes_ige_decrypt(VALUE self, VALUE ciphertext, VALUE key, VALUE iv)
{
    Check_Type(ciphertext, T_STRING);
    Check_Type(key, T_STRING);
    Check_Type(iv, T_STRING);

    long ciphertext_len = RSTRING_LEN(ciphertext);
    long key_len = RSTRING_LEN(key);
    long iv_len = RSTRING_LEN(iv);

    if (key_len != 32) {
        rb_raise(rb_eArgError, "Key must be 32 bytes");
    }
    if (iv_len != 32) {
        rb_raise(rb_eArgError, "IV must be 32 bytes");
    }
    if (ciphertext_len % 16 != 0) {
        rb_raise(rb_eArgError, "Ciphertext length must be multiple of 16");
    }

    AES_KEY aes_key;
    int ret = AES_set_decrypt_key((unsigned char *)RSTRING_PTR(key), 256, &aes_key);
    if (ret != 0) {
        rb_raise(rb_eRuntimeError, "AES_set_decrypt_key failed");
    }

    VALUE plaintext = rb_str_new(NULL, ciphertext_len);
    unsigned char iv_copy[32];
    memcpy(iv_copy, RSTRING_PTR(iv), 32);

    AES_ige_encrypt(
        (unsigned char *)RSTRING_PTR(ciphertext),
        (unsigned char *)RSTRING_PTR(plaintext),
        ciphertext_len,
        &aes_key,
        iv_copy,
        AES_DECRYPT
    );

    return plaintext;
}

.encrypt_ige(plaintext, key, iv) ⇒ Object 



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# File 'ext/aes_ige/aes_ige.c', line 9

static VALUE
aes_ige_encrypt(VALUE self, VALUE plaintext, VALUE key, VALUE iv)
{
    Check_Type(plaintext, T_STRING);
    Check_Type(key, T_STRING);
    Check_Type(iv, T_STRING);

    long plaintext_len = RSTRING_LEN(plaintext);
    long key_len = RSTRING_LEN(key);
    long iv_len = RSTRING_LEN(iv);

    if (key_len != 32) {
        rb_raise(rb_eArgError, "Key must be 32 bytes");
    }
    if (iv_len != 32) {
        rb_raise(rb_eArgError, "IV must be 32 bytes");
    }
    if (plaintext_len % 16 != 0) {
        rb_raise(rb_eArgError, "Plaintext length must be multiple of 16");
    }

    AES_KEY aes_key;
    int ret = AES_set_encrypt_key((unsigned char *)RSTRING_PTR(key), 256, &aes_key);
    if (ret != 0) {
        rb_raise(rb_eRuntimeError, "AES_set_encrypt_key failed");
    }

    VALUE ciphertext = rb_str_new(NULL, plaintext_len);
    unsigned char iv_copy[32];
    memcpy(iv_copy, RSTRING_PTR(iv), 32);

    AES_ige_encrypt(
        (unsigned char *)RSTRING_PTR(plaintext),
        (unsigned char *)RSTRING_PTR(ciphertext),
        plaintext_len,
        &aes_key,
        iv_copy,
        AES_ENCRYPT
    );

    return ciphertext;
}