Hexa format

[joel vennin]

Hello, i'm a new user of the gcrypt library. It is a really great
library with really lots of feature. So thank you for you job !

I've just a simple question for you, i would like to know if there is
a function inside the gcrypt library to convert digest buffer to a
hexa string representation. In fact, i'm using the gcry_md_hash_buffer
function and i want to display on the screen the hexa representation
of the digest buffer.

I've got another question, i want to know what it is more efficient:
  - use the gcry_md_hash_buffer function
  - or use the set of functions:
       - gcry_md_write
       - gcry_md_read

Thank you !

I've you can send me the email to my box because i've not subcribed to the ML