Password algorithm
The protocol 9 and protocol 10 password algorithms are different. In both cases, a seed is provided by the server and a password is provided by the user, and together they are used to generate a scrambled message of the same length as the seed.
Hashing mechanism
A string is hashed to a pair of unsigned longs using the following algorithm:

n1 = 1345345333
n2 = 305419889
add = 7
foreach c in password (ignoring space or tab)
n1 = n1 EOR (((n1 & 63) + add) * c + n1 * 256)
n2 = (n2 * 256) EOR n1
add = add + c

Only the bottom 31 bits of the unsigned longs are used.

Protocol 10
First the password, then the salt are hashed to give two pairs of longs: p1, p2, s1 and s2. These are then used to generate the two seeds of a random number generator, which takes values between 0 and 230-2.

seed1 = p1 EOR s1
seed2 = p2 EOR s2

The random number generator algorithm is:

seed1 = (seed1 * 3 + seed2) mod 230 - 1
seed2 = (seed1 + seed2 + 33) mod 230 - 1
return seed1 / (230 - 1)

The random number generator is called once for each byte of the salt, and the number given is multiplied by 31 and added to 64 to give an ASCII character between '@' and '^'.

msg[i] = chr(64 + rng()*31)

The string just given then has each character exclusive-ored with the random number generator multiplied by 31.

msg[i] = msg[i] EOR(rng()*31)