On Feb 8, 8:46 pm, Jeronimo Bertran
<jeronimo.bert...@newsgroup.nospam> wrote:

for RSA you know private key when you have modulus (p*q) and
decryption exponent. since you have p and q and exponent d - means
that you already have private key.

if you have both exponents and modulus (but no p and q) - its easy to
find p and q.
if you have (p-1)*(q-1) and one of exponents - to find second exponent
just take multiplicative inverse of first exponent mod (p-1)*(q-1).

if you ask about CRT (Chinese Remainder Theorem) optimization for RSA
decryption when you have d, p and q, all you need is just to calculate
multiplicative inverses of P and Q...

all above could be done easily with help of any biginteger library
that supports modular operations...

-Valery