Paine and Smith have come under the scanner for their on-field antics in the third Test.
See Also: ‘It was unbefitting of a captain’, Gavaskar slams Paine for his dirty sledging in 3rd Test
Paine has come under the scanner for using an abusive word during the verbal duel with Ashwin when the Indian held vigil with an injured Hanuma Vihari to eke out a draw for his team, which was chasing a mammoth 407 in the fourth innings.
On the other hand, Smith was accused of cheating as he appeared to scuff up Pant's guard at the crease during a tense final day.
See More: “Very poor” Steve Smith slammed by former cricketers for scuffing up Pant’s batting guard
"Do I have faith in Tim Paine? You have no idea how much faith I have in Tim Paine," Langer quoted as saying by AFP on Wednesday (January 13).
"He didn't have his best day, no doubt about that, but after three years he has hardly put a hair out of place.
"He has been outstanding as the Australian captain in everything he does. He had a frustrating day and we have got to cut him some slack, surely."
Meanwhile, Paine has apologised for his on-field antics, saying that he ended up "looking like a fool" by sledging Ashwin.
The Australian captain also received flak for showing dissent at an umpire’s decision during the second day’s play in Sydney.
While backing Paine to continue as captain "for some time to come", Langer said criticism would come if anyone deviated from the high standards the team has set post the ball-tampering scandal.
"When you set a standard as high as he does, and we do, we understand we get criticised when you fall below that. It's not what we are about," he stated.
"But Tim is an outstanding leader and will continue to be for some time to come yet. He has my 100 percent support."
Commenting on Smith’s scrutiny, the Australia coach said: "As for Steve Smith, I literally cannot believe some of the rubbish I've read — absolute load of rubbish."
"I mean, anyone who knows Steve Smith, he is a bit quirky... and we have all laughed about it for the last couple of years.
"What Steve Smith does at the crease he does it probably most games, he's just thinking about the game. Anyone who suggests for one millisecond he was trying to do something untoward, they're way out of line.
"On that wicket, that was that flat, and it was like concrete, you'd need 15-inch spikes to make an indent on the crease and he went nowhere near the crease," Langer added.
"So seriously, I thought that was absolutely ludicrous."
By securing a famous draw in Sydney, Team India kept the series levelled at 1-1 going into the fourth Test, starting January 15 in Brisbane.
(With AFP inputs)