MD5 Hash String Characters

[NeXEA]

Hello, just wondering, does the MD5 hash's only contain 0-9 and the letters A-F or does it contain the whole spectrum of Alphanumeric characters.

[laserlight]

NeXEA wrote:

does the MD5 hash's only contain 0-9 and the letters A-F or does it contain the whole spectrum of Alphanumeric characters.

An MD5 hash is an integer. When you represent an integer in hexadecimal using the conventional notation, you would only use the digits 0 to 9 and the letters A to F. You could represent the integer in base 36 and it could well "contain the whole spectrum of Alphanumeric characters", or you could use some unconventional notation and then there might be no alphanumeric characters at all.

[Weedpacket]

And, being an integer, it can be written in decimal; in which case it could potentially be anything between 0 and 340,282,366,920,938,463,463,374,607,431,768,211,455 inclusive. And of course those could be represented as "zero" and "three hundred forty undecillion two hundred eighty-two decillion three hundred sixty-six nonillion nine hundred twenty octillion nine hundred thirty-eight septillion four hundred sixty-three sextillion four hundred sixty-three quintillion three hundred seventy-four quadrillion six hundred seven trillion four hundred thirty-one billion seven hundred sixty-eight million two hundred eleven thousand four hundred fifty-five".

Writing it as 32 hex characters is usually more convenient, though.

[NogDog]

Note that the default behavior of the PHP [man]md5/man function is to return the result as a 32-character hexadecimal string.

[Weedpacket]

...and that there is the option of returning it as a string of sixteen bytes (which is equivalent to writing it in base 256).