C++ EVP_Cipher函数代码示例

static int FIPS_des3_test(void)
{
    int ret = 0;
    unsigned char pltmp[8];
    unsigned char citmp[8];
    unsigned char key[] =
    {   1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
        19, 20, 21, 22, 23, 24
    };
    unsigned char plaintext[] = { 'e', 't', 'a', 'o', 'n', 'r', 'i', 's' };
    EVP_CIPHER_CTX ctx;
    EVP_CIPHER_CTX_init(&ctx);
    if (EVP_CipherInit_ex(&ctx, EVP_des_ede3_ecb(), NULL, key, NULL, 1) <= 0)
        goto err;
    EVP_Cipher(&ctx, citmp, plaintext, 8);
    if (EVP_CipherInit_ex(&ctx, EVP_des_ede3_ecb(), NULL, key, NULL, 0) <= 0)
        goto err;
    EVP_Cipher(&ctx, pltmp, citmp, 8);
    if (memcmp(pltmp, plaintext, 8))
        goto err;
    ret = 1;
err:
    EVP_CIPHER_CTX_cleanup(&ctx);
    return ret;
}

/*
 * This function decrypts a buffer using AES GCM mode
 *
 * Parameters:
 *	c	Crypto context
 *	buf	data to encrypt
 *	enc_len	length of encrypt buffer
 */
err_status_t aes_gcm_openssl_decrypt (aes_gcm_ctx_t *c, unsigned char *buf, 
	                              unsigned int *enc_len)
{
    if (c->dir != direction_encrypt && c->dir != direction_decrypt) {
        return (err_status_bad_param);
    }

    /*
     * Set the tag before decrypting
     */
    EVP_CIPHER_CTX_ctrl(&c->ctx, EVP_CTRL_GCM_SET_TAG, c->tag_len, 
	                buf + (*enc_len - c->tag_len));
    EVP_Cipher(&c->ctx, buf, buf, *enc_len - c->tag_len);

    /*
     * Check the tag
     */
    if (EVP_Cipher(&c->ctx, NULL, NULL, 0)) {
        return (err_status_auth_fail);
    }

    /*
     * Reduce the buffer size by the tag length since the tag
     * is not part of the original payload
     */
    *enc_len -= c->tag_len;

    return (err_status_ok);
}

static int
test_cipher(int i, const EVP_CIPHER *c, struct tests *t)
{
    EVP_CIPHER_CTX ectx;
    EVP_CIPHER_CTX dctx;
    void *d;

    if (c == NULL) {
	printf("%s not supported\n", t->name);
	return 0;
    }

    EVP_CIPHER_CTX_init(&ectx);
    EVP_CIPHER_CTX_init(&dctx);

    if (EVP_CipherInit_ex(&ectx, c, NULL, NULL, NULL, 1) != 1)
	errx(1, "%s: %d EVP_CipherInit_ex einit", t->name, i);
    if (EVP_CipherInit_ex(&dctx, c, NULL, NULL, NULL, 0) != 1)
	errx(1, "%s: %d EVP_CipherInit_ex dinit", t->name, i);

    EVP_CIPHER_CTX_set_key_length(&ectx, t->keysize);
    EVP_CIPHER_CTX_set_key_length(&dctx, t->keysize);

    if (EVP_CipherInit_ex(&ectx, NULL, NULL, t->key, t->iv, 1) != 1)
	errx(1, "%s: %d EVP_CipherInit_ex encrypt", t->name, i);
    if (EVP_CipherInit_ex(&dctx, NULL, NULL, t->key, t->iv, 0) != 1)
	errx(1, "%s: %d EVP_CipherInit_ex decrypt", t->name, i);

    d = emalloc(t->datasize);

    if (!EVP_Cipher(&ectx, d, t->indata, t->datasize))
	errx(1, "%s: %d EVP_Cipher encrypt failed", t->name, i);

    if (memcmp(d, t->outdata, t->datasize) != 0) {
	char *s, *s2;
	hex_encode(d, t->datasize, &s);
	hex_encode(t->outdata, t->datasize, &s2);
	errx(1, "%s: %d encrypt not the same: %s != %s", t->name, i, s, s2);
    }

    if (!EVP_Cipher(&dctx, d, d, t->datasize))
	errx(1, "%s: %d EVP_Cipher decrypt failed", t->name, i);

    if (memcmp(d, t->indata, t->datasize) != 0) {
	char *s;
	hex_encode(d, t->datasize, &s);
	errx(1, "%s: %d decrypt not the same: %s", t->name, i, s);
    }
    if (t->outiv)
	/* XXXX check  */;

    EVP_CIPHER_CTX_cleanup(&ectx);
    EVP_CIPHER_CTX_cleanup(&dctx);
    free(d);

    return 0;
}

int
_krb5_evp_encrypt_iov(krb5_context context,
		      struct _krb5_key_data *key,
		      struct krb5_crypto_iov *iov,
		      int niov,
		      krb5_boolean encryptp,
		      int usage,
		      void *ivec)
{
    size_t blocksize, blockmask, wholeblocks;
    struct _krb5_evp_schedule *ctx = key->schedule->data;
    unsigned char tmp[EVP_MAX_BLOCK_LENGTH];
    EVP_CIPHER_CTX *c;
    struct _krb5_evp_iov_cursor cursor;

    c = encryptp ? &ctx->ectx : &ctx->dctx;

    blocksize = EVP_CIPHER_CTX_block_size(c);

    blockmask = ~(blocksize - 1);

    if (ivec)
	EVP_CipherInit_ex(c, NULL, NULL, NULL, ivec, -1);
    else
	EVP_CipherInit_ex(c, NULL, NULL, NULL, zero_ivec, -1);

    _krb5_evp_iov_cursor_init(&cursor, iov, niov);

    while (!_krb5_evp_iov_cursor_done(&cursor)) {

	/* Number of bytes of data in this iovec that are in whole blocks */
        wholeblocks = cursor.current.length & ~blockmask;

        if (wholeblocks != 0) {
            EVP_Cipher(c, cursor.current.data,
                       cursor.current.data, wholeblocks);
            _krb5_evp_iov_cursor_advance(&cursor, wholeblocks);
        }

        /* If there's a partial block of data remaining in the current
         * iovec, steal enough from subsequent iovecs to form a whole block */
        if (cursor.current.length > 0 && cursor.current.length < blocksize) {
	    /* Build up a block's worth of data in tmp, leaving the cursor
	     * pointing at where we started */
            _krb5_evp_iov_cursor_fillbuf(&cursor, tmp, blocksize, NULL);

            EVP_Cipher(c, tmp, tmp, blocksize);

            /* Copy the data in tmp back into the iovecs that it came from,
             * advancing the cursor */
            _krb5_evp_iov_cursor_fillvec(&cursor, tmp, blocksize);
        }
    }

    return 0;
}

void
cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src, u_int len)
{
	if (len % cc->cipher->block_size)
		fatal("cipher_encrypt: bad plaintext length %d", len);
#ifdef SSH_OLD_EVP
	EVP_Cipher(&cc->evp, dest, (u_char *)src, len);
#else
	if (EVP_Cipher(&cc->evp, dest, (u_char *)src, len) == 0)
		fatal("evp_crypt: EVP_Cipher failed");
#endif
}

static int
ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, size_t len)
{
	struct ssh1_3des_ctx *c;

	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL)
		return 0;
	if (EVP_Cipher(&c->k1, dest, __UNCONST(src), len) == 0 ||
	    EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
	    EVP_Cipher(&c->k3, dest, dest, len) == 0)
		return 0;
	return 1;
}

static int
ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, size_t len)
{
	struct ssh1_3des_ctx *c;

	if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
		error("ssh1_3des_cbc: no context");
		return (0);
	}
	if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
	    EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
	    EVP_Cipher(&c->k3, dest, dest, len) == 0)
		return (0);
	return (1);
}

static int
test_bulk_cipher(const char *cname, const EVP_CIPHER *c)
{
    static unsigned char key[16];
    static unsigned char iv[16];
    int i;
    int64_t M = 0;

    for (i = 0; i < loops; i++) {
        EVP_CIPHER_CTX ectx;
        EVP_CIPHER_CTX dctx;

        STATS_START(M)

        EVP_CIPHER_CTX_init(&ectx);
        EVP_CIPHER_CTX_init(&dctx);

        if (EVP_CipherInit_ex(&ectx, c, NULL, NULL, NULL, 1) != 1)
	    errx(1, "can't init encrypt");
        if (EVP_CipherInit_ex(&dctx, c, NULL, NULL, NULL, 0) != 1)
	    errx(1, "can't init decrypt");

        EVP_CIPHER_CTX_set_key_length(&ectx, sizeof(key));
        EVP_CIPHER_CTX_set_key_length(&dctx, sizeof(key));

        if (EVP_CipherInit_ex(&ectx, NULL, NULL, key, iv, 1) != 1)
	    errx(1, "can't init encrypt");
        if (EVP_CipherInit_ex(&dctx, NULL, NULL, key, iv, 0) != 1)
	    errx(1, "can't init decrypt");

        if (!EVP_Cipher(&ectx, d, d, len))
	    errx(1, "can't encrypt");
        if (!EVP_Cipher(&dctx, d, d, len))
	    errx(1, "can't decrypt");

        EVP_CIPHER_CTX_cleanup(&ectx);
        EVP_CIPHER_CTX_cleanup(&dctx);

        STATS_END(M);

	if (d[0] != 0x00 || d[len - 1] != ((len - 1) & 0xff))
	    errx(1, "encrypt/decrypt inconsistent");
    }

    printf("%s: mean time %llu usec%s\n", cname, M, (M == 1) ? "" : "s");

    return 0;
}

/*
 * cipher_crypt() operates as following:
 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
 * Theses bytes are treated as additional authenticated data for
 * authenticated encryption modes.
 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
 * This tag is written on encryption and verified on decryption.
 * Both 'aadlen' and 'authlen' can be set to 0.
 * cipher_crypt() returns 0 on success and -1 if the decryption integrity
 * check fails.
 */
int
cipher_crypt(CipherContext *cc, u_int seqnr, u_char *dest, const u_char *src,
    u_int len, u_int aadlen, u_int authlen)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, len,
		    aadlen, authlen, cc->encrypt);
	if (authlen) {
		u_char lastiv[1];

		if (authlen != cipher_authlen(cc->cipher))
			fatal("%s: authlen mismatch %d", __func__, authlen);
		/* increment IV */
		if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
		    1, lastiv))
			fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__);
		/* set tag on decyption */
		if (!cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG,
		    authlen, (u_char *)src + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_SET_TAG", __func__);
	}
	if (aadlen) {
		if (authlen &&
		    EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0)
			fatal("%s: EVP_Cipher(aad) failed", __func__);
		memcpy(dest, src, aadlen);
	}
	if (len % cc->cipher->block_size)
		fatal("%s: bad plaintext length %d", __func__, len);
	if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen,
	    len) < 0)
		fatal("%s: EVP_Cipher failed", __func__);
	if (authlen) {
		/* compute tag (on encrypt) or verify tag (on decrypt) */
		if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) {
			if (cc->encrypt)
				fatal("%s: EVP_Cipher(final) failed", __func__);
			else
				return -1;
		}
		if (cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG,
		    authlen, dest + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_GET_TAG", __func__);
	}
	return 0;
}

krb5_error_code
_krb5_evp_encrypt(krb5_context context,
		struct _krb5_key_data *key,
		void *data,
		size_t len,
		krb5_boolean encryptp,
		int usage,
		void *ivec)
{
    struct _krb5_evp_schedule *ctx = key->schedule->data;
    EVP_CIPHER_CTX *c;
    c = encryptp ? &ctx->ectx : &ctx->dctx;
    if (ivec == NULL) {
	/* alloca ? */
	size_t len2 = EVP_CIPHER_CTX_iv_length(c);
	void *loiv = malloc(len2);
	if (loiv == NULL)
	    return krb5_enomem(context);
	memset(loiv, 0, len2);
	EVP_CipherInit_ex(c, NULL, NULL, NULL, loiv, -1);
	free(loiv);
    } else
	EVP_CipherInit_ex(c, NULL, NULL, NULL, ivec, -1);
    EVP_Cipher(c, data, data, len);
    return 0;
}

int
tls_process_record_data(struct SSLConnection *conn, const opaque *fragment, const int len,
                        uint8_t **out, uint32_t *outl)
{
    EVP_CIPHER_CTX *evp;
    unsigned char pad;
    unsigned char *decoded;
    uint32_t dlen;

    if (conn->direction == 0) {
        evp = &conn->client_cipher_ctx;
    } else {
        evp = &conn->server_cipher_ctx;
    }

    decoded = sng_malloc(len);
    EVP_Cipher(evp, decoded, (unsigned char *) fragment, len);

    // Get padding counter and remove from data
    pad = decoded[len - 1];
    dlen = (len - (pad + 1) - /* Trailing MAC */20);

    if ((int32_t)dlen > 0 && dlen <= *outl) {
        memcpy(*out, decoded, dlen);
        *outl = dlen;
    }

    // Clenaup decoded memory
    sng_free(decoded);
    return *outl;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_des_checksum(krb5_context context,
		   const EVP_MD *evp_md,
		   struct _krb5_key_data *key,
		   const void *data,
		   size_t len,
		   Checksum *cksum)
{
    struct _krb5_evp_schedule *ctx = key->schedule->data;
    EVP_MD_CTX *m;
    DES_cblock ivec;
    unsigned char *p = cksum->checksum.data;

    krb5_generate_random_block(p, 8);

    m = EVP_MD_CTX_create();
    if (m == NULL)
	return krb5_enomem(context);

    EVP_DigestInit_ex(m, evp_md, NULL);
    EVP_DigestUpdate(m, p, 8);
    EVP_DigestUpdate(m, data, len);
    EVP_DigestFinal_ex (m, p + 8, NULL);
    EVP_MD_CTX_destroy(m);
    memset (&ivec, 0, sizeof(ivec));
    EVP_CipherInit_ex(&ctx->ectx, NULL, NULL, NULL, (void *)&ivec, -1);
    EVP_Cipher(&ctx->ectx, p, p, 24);

    return 0;
}

int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, 
			const EVP_CIPHER *cipher, ENGINE *impl)
	{
	static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];
#ifdef OPENSSL_FIPS
	if (FIPS_mode())
		{
		/* If we have an ENGINE need to allow non FIPS */
		if ((impl || ctx->cctx.engine)
			&& !(ctx->cctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW))

			{
			EVPerr(EVP_F_CMAC_INIT, EVP_R_DISABLED_FOR_FIPS);
			return 0;
			}
		/* Other algorithm blocking will be done in FIPS_cmac_init,
		 * via FIPS_cipherinit().
		 */
		if (!impl && !ctx->cctx.engine)
			return FIPS_cmac_init(ctx, key, keylen, cipher, NULL);
		}
#endif
	/* All zeros means restart */
	if (!key && !cipher && !impl && keylen == 0)
		{
		/* Not initialised */
		if (ctx->nlast_block == -1)
			return 0;
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
			return 0;
		return 1;
		}
	/* Initialiase context */
	if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))
		return 0;
	/* Non-NULL key means initialisation complete */
	if (key)
		{
		int bl;
		if (!EVP_CIPHER_CTX_cipher(&ctx->cctx))
			return 0;
		if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))
			return 0;
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))
			return 0;
		bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);
		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))
			return 0;
		make_kn(ctx->k1, ctx->tbl, bl);
		make_kn(ctx->k2, ctx->k1, bl);
		OPENSSL_cleanse(ctx->tbl, bl);
		/* Reset context again ready for first data block */
		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))
			return 0;
		/* Zero tbl so resume works */
		memset(ctx->tbl, 0, bl);
		ctx->nlast_block = 0;
		}
	return 1;
	}

/*
 * This function processes the AAD
 *
 * Parameters:
 *	c	Crypto context
 *	aad	Additional data to process for AEAD cipher suites
 *	aad_len	length of aad buffer
 */
static srtp_err_status_t srtp_aes_gcm_openssl_set_aad(void *cv,
                                                      const uint8_t *aad,
                                                      uint32_t aad_len)
{
    srtp_aes_gcm_ctx_t *c = (srtp_aes_gcm_ctx_t *)cv;
    int rv;

    /*
     * Set dummy tag, OpenSSL requires the Tag to be set before
     * processing AAD
     */

    /*
     * OpenSSL never write to address pointed by the last parameter of
     * EVP_CIPHER_CTX_ctrl while EVP_CTRL_GCM_SET_TAG (in reality,
     * OpenSSL copy its content to the context), so we can make
     * aad read-only in this function and all its wrappers.
     */
    unsigned char dummy_tag[GCM_AUTH_TAG_LEN];
    memset(dummy_tag, 0x0, GCM_AUTH_TAG_LEN);
    EVP_CIPHER_CTX_ctrl(c->ctx, EVP_CTRL_GCM_SET_TAG, c->tag_len, &dummy_tag);

    rv = EVP_Cipher(c->ctx, NULL, aad, aad_len);
    if (rv != aad_len) {
        return (srtp_err_status_algo_fail);
    } else {
        return (srtp_err_status_ok);
    }
}

krb5_error_code
_krb5_des_checksum(krb5_context context,
		   CCDigestAlg alg,
		   struct _krb5_key_data *key,
		   const void *data,
		   size_t len,
		   Checksum *cksum)
{
    struct _krb5_evp_schedule *ctx = key->schedule->data;
    CCDigestRef m;
    unsigned char ivec[8];
    unsigned char *p = cksum->checksum.data;

    krb5_generate_random_block(p, 8);

    m = CCDigestCreate(alg);
    if (m == NULL) {
	krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
	return ENOMEM;
    }

    CCDigestUpdate(m, p, 8);
    CCDigestUpdate(m, data, len);
    CCDigestFinal(m, p + 8);
    CCDigestDestroy(m);
    memset (&ivec, 0, sizeof(ivec));
    EVP_CipherInit_ex(&ctx->ectx, NULL, NULL, NULL, (void *)ivec, -1);
    EVP_Cipher(&ctx->ectx, p, p, 24);

    return 0;
}