ddnnsssseecc--kkeeyyggeenn generates keys for DNSSEC (Secure DNS), as defined in RFC 2535 and RFC 4034. It can also generate keys for use with TSIG (Transaction Signatures), as defined in RFC 2845.
-a _a_l_g_o_r_i_t_h_m
Selects the cryptographic algorithm. The value of
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must be one of RSAMD5 (RSA) or RSASHA1, DSA, DH (Diffie Hellman), or HMAC-MD5. These values are case insensitive.
Note 1: that for DNSSEC, RSASHA1 is a mandatory to implement algorithm, and DSA is recommended. For TSIG, HMAC-MD5 is mandatory.
Note 2: HMAC-MD5 and DH automatically set the -k flag.
-b _k_e_y_s_i_z_e Specifies the number of bits in the key. The choice of key size depends on the algorithm used. RSAMD5 / RSASHA1 keys must be between 512 and 2048 bits. Diffie Hellman keys must be between 128 and 4096 bits. DSA keys must be between 512 and 1024 bits and an exact multiple of 64. HMAC-MD5 keys must be between 1 and 512 bits.
-n _n_a_m_e_t_y_p_e Specifies the owner type of the key. The value of nnaammeettyyppee must either be ZONE (for a DNSSEC zone key (KEY/DNSKEY)), HOST or ENTITY (for a key associated with a host (KEY)), USER (for a key associated with a user(KEY)) or OTHER (DNSKEY). These values are case insensitive. Defaults to ZONE for DNSKEY generation.
-c _c_l_a_s_s Indicates that the DNS record containing the key should have the specified class. If not specified, class IN is used.
-e If generating an RSAMD5/RSASHA1 key, use a large exponent.
-f _f_l_a_g Set the specified flag in the flag field of the KEY/DNSKEY record. The only recognized flag is KSK (Key Signing Key) DNSKEY.
-g _g_e_n_e_r_a_t_o_r If generating a Diffie Hellman key, use this generator. Allowed values are 2 and 5. If no generator is specified, a known prime from RFC 2539 will be used if possible; otherwise the default is 2.
-h Prints a short summary of the options and arguments to ddnnsssseecc--kkeeyyggeenn.
-k Generate KEY records rather than DNSKEY records.
-p _p_r_o_t_o_c_o_l Sets the protocol value for the generated key. The protocol is a number between 0 and 255. The default is 3 (DNSSEC). Other possible values for this argument are listed in RFC 2535 and its successors.
-r _r_a_n_d_o_m_d_e_v Specifies the source of randomness. If the operating system does not provide a _/_d_e_v_/_r_a_n_d_o_m or equivalent device, the default source of randomness is keyboard input. _r_a_n_d_o_m_d_e_v specifies the name of a character device or file containing random data to be used instead of the default. The special value _k_e_y_b_o_a_r_d indicates that keyboard input should be used.
-s _s_t_r_e_n_g_t_h Specifies the strength value of the key. The strength is a number between 0 and 15, and currently has no defined purpose in DNSSEC.
-t _t_y_p_e Indicates the use of the key. ttyyppee must be one of AUTHCONF, NOAUTHCONF, NOAUTH, or NOCONF. The default is AUTHCONF. AUTH refers to the ability to authenticate data, and CONF the ability to encrypt data.
-v _l_e_v_e_l Sets the debugging level.
When ddnnsssseecc--kkeeyyggeenn completes successfully, it prints a string of the form _K_n_n_n_n_._+_a_a_a_+_i_i_i_i_i to the standard output. This is an identification string for the key it has generated.
ddnnsssseecc--kkeeyyggeenn creates two files, with names based on the printed string. _K_n_n_n_n_._+_a_a_a_+_i_i_i_i_i_._k_e_y contains the public key, and _K_n_n_n_n_._+_a_a_a_+_i_i_i_i_i_._p_r_i_v_a_t_e contains the private key.
The _._k_e_y file contains a DNS KEY record that can be inserted into a zone file (directly or with a $INCLUDE statement).
The _._p_r_i_v_a_t_e file contains algorithm-specific fields. For obvious security reasons, this file does not have general read permission.
Both _._k_e_y and _._p_r_i_v_a_t_e files are generated for symmetric encryption algorithms such as HMAC-MD5, even though the public and private key are equivalent.
To generate a 768-bit DSA key for the domain eexxaammppllee..ccoomm, the following command would be issued:
ddnnsssseecc--kkeeyyggeenn --aa DDSSAA --bb 776688 --nn ZZOONNEE eexxaammppllee..ccoomm
The command would print a string of the form:
KKeexxaammppllee..ccoomm..++000033++2266116600
In this example, ddnnsssseecc--kkeeyyggeenn creates the files _K_e_x_a_m_p_l_e_._c_o_m_._+_0_0_3_+_2_6_1_6_0_._k_e_y and _K_e_x_a_m_p_l_e_._c_o_m_._+_0_0_3_+_2_6_1_6_0_._p_r_i_v_a_t_e.
ddnnsssseecc--ssiiggnnzzoonnee(8), BIND 9 Administrator Reference Manual, RFC 2539, RFC 2845, RFC 4033.
Internet Systems Consortium