# openssl_get_md_methods

(PHP 5 >= 5.3.0, PHP 7)

openssl_get_md_methods — 获取可用的摘要算法

### 说明

openssl_get_md_methods ([ bool `$aliases` = false ] ) : array

获取可用的摘要算法列表

### 参数

`aliases`

  设置为 `TRUE` 时，返回的array中将会包含摘要的别名.

### 返回值

含有可用摘要算法的数组

### 范例

Example #1 openssl_get_md_methods() 范例：

显示了可用的摘要，以及哪些别名可能是可用的。

    <?php
    $digests             = openssl_get_md_methods();
    $digests_and_aliases = openssl_get_md_methods(true);
    $digest_aliases      = array_diff($digests_and_aliases, $digests);

    print_r($digests);

    print_r($digest_aliases);

    ?>

以上例程的输出类似于：

    Array
    (
        [0] => DSA
        [1] => DSA-SHA
        [2] => MD2
        [3] => MD4
        [4] => MD5
        [5] => RIPEMD160
        [6] => SHA
        [7] => SHA1
        [8] => SHA224
        [9] => SHA256
        [10] => SHA384
        [11] => SHA512
        [12] => dsaEncryption
        [13] => dsaWithSHA
        [14] => ecdsa-with-SHA1
        [15] => md2
        [16] => md4
        [17] => md5
        [18] => ripemd160
        [19] => sha
        [20] => sha1
        [21] => sha224
        [22] => sha256
        [23] => sha384
        [24] => sha512
    )
    Array
    (
        [2] => DSA-SHA1
        [3] => DSA-SHA1-old
        [4] => DSS1
        [9] => RSA-MD2
        [10] => RSA-MD4
        [11] => RSA-MD5
        [12] => RSA-RIPEMD160
        [13] => RSA-SHA
        [14] => RSA-SHA1
        [15] => RSA-SHA1-2
        [16] => RSA-SHA224
        [17] => RSA-SHA256
        [18] => RSA-SHA384
        [19] => RSA-SHA512
        [28] => dsaWithSHA1
        [29] => dss1
        [32] => md2WithRSAEncryption
        [34] => md4WithRSAEncryption
        [36] => md5WithRSAEncryption
        [37] => ripemd
        [39] => ripemd160WithRSA
        [40] => rmd160
        [43] => sha1WithRSAEncryption
        [45] => sha224WithRSAEncryption
        [47] => sha256WithRSAEncryption
        [49] => sha384WithRSAEncryption
        [51] => sha512WithRSAEncryption
        [52] => shaWithRSAEncryption
        [53] => ssl2-md5
        [54] => ssl3-md5
        [55] => ssl3-sha1
    )

### 参见

- openssl_digest() - 计算摘要
- openssl_get_cipher_methods() - 获取可用的加密算法