nmap scan service and port for ssl ciphers - ssl

Question

When i run the command
nmap --script ssl-enum-ciphers hostname
I get the output of ciphers with a grade next to it. For example :
| ciphers:
| TLS_RSA_WITH_3DES_EDE_CBC_SHA - D
| TLS_RSA_WITH_AES_128_CBC_SHA - A
| TLS_RSA_WITH_AES_256_CBC_SHA - A
My question is What is A - D stand for ? I assume A being the highest and best. Is it right ?
Thanks

Answer 1

A-D stand for strength.
Using nmap (https://nmap.org) to scan SSL cipher you can see report like below:
nmap -p 443 --script ssl-enum-ciphers example.com
TLSv1.2:
ciphers:
TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 768) - C
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 (dh 768) - C
TLS_DHE_RSA_WITH_AES_256_CBC_SHA (dh 768) - B
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (dh 768) - B
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (secp160k1) - A
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (secp160k1) - A
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (secp160k1) - A
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (secp160k1) - A
TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
TLS_RSA_WITH_AES_128_CBC_SHA256 (rsa 2048) - A
TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
TLS_RSA_WITH_AES_256_CBC_SHA256 (rsa 2048) - A
compressors:
NULL
cipher preference: client
warnings:
64-bit block cipher 3DES vulnerable to SWEET32 attack
Key exchange (dh 768) of lower strength than certificate key
Key exchange (secp160k1) of lower strength than certificate key
least strength: C
See the bold text. First bold lines are ciphers with corresponding strength. And last bold line is summary strength based on minimum ciphers strength.