Meditation technique proposed by the Buddha What type of meditation is proposed by the Buddha for attaining self realization? Is it Vipassanna medition? Is Mindfulness meditation the same as Vipassanna? Which scripture mentions these techniques?
If we take the Pali Canon as been the closest we have to the word of the Buddha then there isn't a wealth of specific meditation advice in there when compared to other types of advice such as ethical.

However there are two sutras that do give specific advice these being


Anapanasati Sutra (Mindfulness of breathing)
Satipatthana Sutra (The Way of Mindfulness)


Both these sutras encapsulate samatha and vipassana practices. For example the Anapansati Sutra begins with body contemplation but end up in the forth tetrad contemplating the very stuff of existence 


Contemplating impermanence   
Contemplating fading of lust
Contemplating cessation
Contemplating relinquishment


The Satipatthana sutra also start with calming practices but ultimately the practioner is asked to comtemplate the four noble truths


  Here, O bhikkhus, a bhikkhu understands: 'This is suffering,'
  according to reality; he understands: 'This is the origin of
  suffering,' according to reality; he understands: 'This is the
  cessation of suffering,' according to reality; and he understands:
  'This is the road leading to the cessation of suffering,' according to
  realty.


You can't get much more vipassana than that!

If I can also take the opportunity to recommend the book Satipaṭṭhāna: The Direct Path to Realization by Analayo. This is a tremendous book for anyone interested in really drilling into the Satipaṭṭhāna sutra and getting to grips with meditation as the Buddha taught it. It's heavy on the footnotes and is more of a heady read other Dharma books but I've read it once and it's certainly on my list to go through again.