> Cool.. but the key below has 128 bytes in total, but reported as being
> 1023-bit
>
> -----
> Modulus (1023 bit):
> 5d:10:63:d3:d8:00:2a:50:ab:65:8a:f0:92:83:b0:
> 6a:39:e3:0c:38:aa:f5:32:23:71:25:8e:4a:8d:50:
> fd:80:a3:95:59:33:27:92:88:d0:1d:28:dd:05:7c:
> b6:a0:5e:68:9e:b4:70:c9:bd:28:8a:fb:6d:95:0a:
> 38:83:f9:8d:15:b1:3a:33:bf:d7:ab:1c:5e:1b:d3:
> d6:c1:1a:f8:05:7f:ef:22:23:48:ef:48:a2:8d:99:
> 90:10:81:8a:54:dd:16:9e:7f:d0:88:a8:b7:34:68:
> be:4d:8f:dc:4b:5d:d9:72:c5:a4:88:a6:40:fa:f2:
> f7:16:79:a8:35:3d:f2:ad
> Exponent: 3 (0x3)
> -----
Half of the 128-byte numbers can be expressed in 1,023 bits. This one
can,
since it's high nibble is '5' or '0100'. The leading zero can be omitted,
resulting in 1,023 bits.
> I notice that for 1024-bit RSA key generated by openssl, the modulus has
> 129 bytes but having the first byte = 0. Why is this?, for example:
>
> -----
> Modulus (1024 bit):
> 00:d8:6e:77:67:5e:29:bb:4e:83:52:fe:fa:fc:58:
> 04:d8:07:3e:43:11:92:10:45:dc:f2:f7:7a:77:49:
> 91:cf:cc:0d:5e:ec:d9:44:15:2d:61:19:cd:9d:79:
> 9e:27:80:61:6c:a3:db:34:21:cf:87:60:7a:e4:d9:
> a5:02:59:57:fb:4e:8c:e4:32:fb:5e:cb:1a:99:7b:
> 76:b2:79:ae:2f:1f:62:1d:f6:fc:9e:32:e5:bd:46:
> 8f:c7:05:63:aa:10:2c:be:60:46:4a:44:c5:63:94:
> b1:ab:d5:c5:33:cd:d7:69:f0:2b:36:54:dd:82:92:
> 66:6c:0d:50:81:a1:23:79:67
> Exponent: 65537 (0x10001)
> -----
Why is what? This number requires 1,024 bits to express it. The lead
nibble
is 'd' in hex, which is '1101', so there's no leading zero in the nibble
that can be dropped.
DS
______________________________________________________________________
OpenSSL Project http://www.openssl.org
User Support Mailing List [email protected]
Automated List Manager [EMAIL PROTECTED]
