Sir, we're not able to chat with you. It says Gayathri. Yeah, I know because of the network issue, I left the meeting accidentally. So I joined now. I will be the host now. So I think you can not just ask me. Just let me check one just a second. No, I'm fine. I am the host now so you can chat with me. Sir, can you just send me a message? Just a second. Can you see this now? Yeah, it's fine with all of you. Yes, so last class we had discussed the levelling effect of water. Okay, and I asked you to find out the H plus concentration if pH is given as 2.1. Okay, so almost all of you have tried. So the last question that we were discussing is, suppose the pH value is given, right, I've given you this value 2.1. What is the concentration of H plus? Okay, concentration of H plus you need to find out. This said last class also that few know log values you have to memorize like log 2, log 3, log 5, at least these three. I'll give you all these value here. The value of log 2 is 0.301. 0.301. Log 3 value is 0.477 log 5 is 0.6999. And log 7 is 0.845. This is the exact value we have. For calculation, sometimes we also assume this to be 0.48 or this is almost equals to 0.704 calculation. We can do that assumption. Okay, now based on this, how can we get the value of H plus you see. We have this pH value 2.1, which we can write 3 minus 0.9. 3 minus 0.9. 0.9 we can write as this a second. Hello. Yeah, sorry, you got a call. Yeah, so 0.9 we can write 3 into 0.30. Why this I have written because 0.30 the value we have it is log 2. Okay, so we can further write this as 3 minus 3 log 2, which again we can write 3 as in minus of log 10 to the power minus 3 is 3 only minus 3 log 2 we can write log 2 to the power 3, which is 8. If you take this minus out, this becomes minus of log 8 into 10 to the power minus 3. Okay, so pH, we know this pH is equals to minus of log 8 into 10 to the power minus 3 and pH we know it is minus log of H plus. So if you compare the two, obviously the H plus concentration we are getting here is 8 into 10 to the power minus 3. This is the answer we have. Clear any doubt in this? Yes. So like this you can solve. You can also write this as 2 plus 0.1, but we are not writing it as 2 plus 0.1 because we do not have 0.1 as any log value here. 7 into, how it is 7 you are getting? Yeah, there are many different ways we can write. Just one of the method is this, the number 2.1 can be represented in many different ways. Yeah, that's why 3 minus this if you do that it is 2.155 since we have 2.1 over here. So approximation we can take like this 2.10 will have over there. Actually in this way you know you should understand that how to proceed. Correct. So we have 10 to the power minus 3 here in the option it is given 10 to the power minus 3. It means you need to write 3 plus or 3 minus something. One of the way is this. It's not like you cannot solve this by other means. You can do that. One of the way is this. So we were discussing calculation of pH. Right. So there are different, different, you know, conditions under which we need to calculate the pH of the solution of the mixture. Correct. What you need to do, first of all, for the calculation of pH you just require the concentration of H plus, but how to get this concentration of H plus in different different conditions that is important. The basic formula is this only you need to have the concentration of H plus substituted here you'll get the answer then. So the first or the next condition we have right down calculation of pH or pH of pH of the mixture of strong acid and strong base strong acid and strong base. So there are three different conditions we have over here. Right. So what is happening here, acid we take base will mix the two. Obviously acid and base will neutralize each other. Right. So it is a neutralization reaction. The solution that you get from this when you mix acid and base. The solution could be acidic, could be basic, could be neutral, all three possibilities are there. So under what condition the solution is acidic that depends upon what amount of acid or base we are taking. If acid is in excess, right, then the solution would be acidic. If base in excess solution would be basic. If both are exactly equal, then the solution would be neutral. Okay. So the case one what we have. We are assuming case one here in which the number of equivalents of acid and a VA is the number of equivalents normality into volume. If it is greater than the number of equivalent of base. If this is given, they will give you the number of equivalents like normality or molarity will be given like normality of acid and volume would be given if normality is not given, then molarity will be given. And we know normality is equals to molarity into n factor. Okay, so accordingly you can calculate and the VB is the normality and volume of the base we have. So when we have this, if you mix the two, depending upon the number of equivalents of acid and base we can have the property of the solution. I am assuming here that the case one is the number of equivalents of acid is greater than the number of equivalents of base. And under this condition, this base will be the limiting reagent. This is the base will be the limiting reagent and when base is the limiting reagent, then the solution is what? The solution is acidic in nature. Mixer will be acidic because we have acid left. And when the mixture is acidic, then we'll get H plus concentration. We'll get H plus concentration as the number of equivalents of acid that is NA VA and some part of it gets neutralized. We know the number of equivalents which gets neutralized is equals to the number of equivalents of base because we know equal equivalents react. The equivalents of base that we have equal equivalents of acid will react. This amount of H plus you'll get divided by the total volume VA plus VB. So this is the formula of H plus and that is what we need to know. We need to have the formula of H plus the value of H plus concentration. And then we can substitute this in pH formula you'll get the pH of the solution. Similarly, we can have the second case, I'm sorry, case two. Case two, I am assuming the number of equivalents of acid is less than the number of equivalents of base. So here the condition is exactly opposite. Hence the result is also exactly opposite. This NA VA acid is the limiting reagent here. And when acid is the limiting reagent, then solution is basic in nature. And when the solution is basic, then we'll get OH minus concentration, not H plus OH minus equals to the base which is left. That is the number of equivalents of base minus some part of it will get neutralized by acid by acid divided by the total volume VA plus VB. Once you know OH minus concentration, you can further calculate POH, right, is equals to minus log of OH minus concentration. Once you get POH, you can find out pH is equals to 14 minus POH provided the condition or the temperature is 25 degree Celsius. This is what you need to do in this one. Clear? Now, the third case is, yeah, that also you can do. You can directly divide by 10 to the power minus 14. You'll get H plus concentration and then pH. That also you can do. No problem. Okay. Next case three is when the number of equivalents of acid equals to the number of equivalent of base. In this case, it is the condition of complete neutralization case of complete neutralization. And in this case, pH would be seven. No need to calculate this neutral solution, pH is seven. Got it? Try this question. Calculate the pH of solution. And the solution is we have of H2SO4 and NaOH. H2SO4, it is given 0.01 molar and volume is also given over here. Volume is 200 ml of this. For NaOH, it is 0.05 molar and volume is 300 ml. This is mixed. You need to find out the pH of the solution. Try this. Yes. Done? Yes. So, when you mix this acid and base, what you will get, you see, first of all, you find out the number of equivalents of acid and base. So, molarity is given and volume is given. So, the number of milli equivalents are right. Since the volume is given in ml. So, number of milli equivalents also you can calculate. Not a problem. That is molarity. Number of milli equivalents, what do you want? We can write down here. Normality into volume. Normality is what molarity into n factor of H2SO4 is what? Could you tell me? What is the n factor of H2SO4? 2. So, 0.01 into 2 into volume is 200. So, this is the number of milli equivalent of acid. Number of milli equivalent of base would be its molarity into n factor is 1 only NaOH into 300. I am writing down here as milli equivalent because volume is in ml. So, if you don't write milli equivalent, also the answer won't change. But technically, number of equivalent we cannot write here. That would be wrong. This is the milli equivalent of base. If you solve this, you will get 15 here. 15 milli equivalent of base we have. If you solve this, you will get 4 milli equivalent of acid. So, obviously the one which is less is the limiting reagent. So, acid here is the limiting reagent and this milli equivalent will get neutralized. So, solution would be basic. OH minus concentration would be what? Is equals to 15 minus 4 divided by 300 plus 200 500. It is 11 divided by 500 OH minus concentration. So, when you solve this, you will get 11 by 5 is 2.2 into 10 to the power minus 2. Or we can also write this as 22 into 10 to the power minus 3. So, this is what? OH minus. If you find out TOH here minus log of 22 into 10 to the power minus 3, that would be 3 minus log 22. Log 22 value is 1.3 approximately. Hence, POH is 1.7. PH is 14 minus POH. That is 12.3. This is the answer we have for this question. Done. All of you understood this? This calculation you need to be a bit careful. You have to be in calculation part. Usually what happens? We calculate POH and we answer like this only. PH is this in hurry. I am getting 12.3. No, it is not 11.3. So, for this kind of question, you first calculate the number of equivalents of acid and base, find out which one is more, which one is less. Accordingly, you can get the property of solution, acidic and basic and then H plus or OH minus concentration you can find. Okay. Now, what happens if you have a mixture of acid? PH of mixture of acid. Suppose we are mixing two acid here. You can have more than two also, right? You can have more than two. I am assuming two here. So, suppose we have two acid HA1 and HA2 we are mixing. So, HA1 will have its own normality and volume. If not, then molarity will be given. Accordingly, you can find out normality. Similarly, this one will have its own normality into volume. So, when you mix these two into a container, right? Then in this container, the total number of equivalents would be what? In this container, the total number of equivalents would be the number of equivalents of these two acids only, number of equivalents of acid one, number of equivalents of acid two. And that would be N1V1 plus N2V2. This is the number of equivalents. So, further we can write, since we are mixing only acid, the total number of equivalents H plus concentration is N1V1 plus N2V2 divided by V1 plus V2, total volume. This is the formula of H plus and then further we can find out pH from this formula. Look at this question on this. You need to calculate the pH of solution. pH of solution. We are mixing three acids here. H2SO4 we are mixing. We are mixing H3PO4 and we are mixing HCl. Three acid we are mixing. For H2SO4, we have 200 ml, 10 to the power minus two molar solution, H2SO4. H3PO4, we have 200 ml and 1.5 into 10 to the power minus two molar. For HCl it is 200 ml into 2 into 10 to the power minus two molar. This is the data given. You need to find out the pH of the solution. Try this once. Then what is the answer? 1.52. Yeah, that's 1.52 is correct. Absolutely correct. Okay. So, first of all, the number of equivalents, we'll find out the number of milli-equivalents of this. Number of milli-equivalents would be volume into molarity into N factor. And for this one again, volume into molarity into N factor is 3. Here we have volume into molarity into N factor. So, number of equivalents here, it would be 4 milli-equivalent. Here it is 3 into 3, 9 milli-equivalents and here it is 2 into 2, 4 milli-equivalents. Okay. So, total number of equivalents would be this plus this plus this divided by total volume.  We have a 600 ml here. 0.83 into 10 to the power minus two. I think slight change in the answer, actually 100 problem method is this only. H would be 2 minus log of, yes, what is the value you got? Yes, 1.55 approximately you are getting, that's fine. So, 1.55 is the pH value we have. Simple one, for acid, we just need to add the number of equivalents divided by total volume. Next is mixture of acid we got, mixture of bases, third one we write down, pH of the mixture of base. What is the value of log 2.83? Could you tell me? Log of 2.83, 0.45. So, it is 2 minus 0.45, correct. 1.55 approximately the answer is, okay, 1.55 is the answer. pH of the mixture of base again is very simple. Suppose we have two bases, BoH1 and BoH2. If you are mixing the two base, then obviously we will get the concentration of OH minus here, right. So, in this case we will have the total number of equivalents here equals to N1V1 plus N2V2 assuming the normality and volume of base 1 is N1V1 and this is N2V2. So, OH minus concentration would be N1V1 plus N2V2 divided by V1 plus V2, okay. Simple, like we did one question on base acid, similarly you can do it on base. Remember we need to find out pH, OH minus concentration we get, then you can find out H plus concentration and then you can find out pH. Okay, now the next one is pH of solution of weak acid, of weak acid, okay. So, weak acid we have, suppose I'm assuming an acid CS3 COOH, a weak acid we have, we know weak acid are the weak electrolytes, it won't dissociate completely, so it will be CS3 COO minus and H plus, okay. So, I'm assuming the initial concentration of acid is C, this is 0, this is 0, where it dissociates, if the degree of dissociation I'm assuming alpha to attain equilibrium state, so it is C minus C alpha, this is C alpha and this is C alpha. Ka is equals to concentration of product that is CS3 COO minus H plus CH3 COOH, this is the formula we have, which further we can write C alpha square by 1 minus alpha, this is what we can do. Now, if you're assuming alpha is very small, so we can write 1 minus alpha almost equals to 1, okay, hence Ka is equals to C alpha square, again you focus on this, we need to find out H plus concentration, that is C alpha we need to find out. Once you know this H plus, we can find out pH, okay, to get C alpha what we do, we'll multiply both side by C here, so C times Ka is equals to C square alpha square, so C alpha is equals to root under C Ka, which is nothing but the H plus concentration, copy this down, okay. So H plus concentration we got, now when you substitute this in order to find out pH, pH is equals to minus log of H plus, so H plus concentration is minus log of C Ka to the power 1 by 2, which is further equals to minus half log C plus log Ka. Minus sign if you take in, then it becomes half minus log Ka is P Ka minus log C, this is pH, formula of pH under this condition, yeah, this is again I'll go back, make sure of base, okay, okay. Now one more very important thing here, copy this down first, done this all of you, tell me, finished now, okay, now this is the formula of pH, but you see here, listen to me very carefully all of you, the concentration of H plus we get, once we have this assumption isn't it, we are assuming this that we do in most of the cases, but this formula is based upon this assumption, which we cannot always make. If you can make this assumption, then the formula of pH is correct, if you cannot make this assumption, then the only way is what we know this H plus concentration C alpha you need to find out C alpha and then you can get the answer. But the formula that I have written pH is equals to half of P Ka minus log C, this we can only use when we can make this assumption, if 1 minus alpha is almost equals to 1, this is the condition we have then we can use this. If we cannot, if you do not have 1 minus alpha equals to 1, then we know the concentration of H plus, I'll write down here, concentration of H plus equals to C alpha, and this is true in all condition. This is true in all condition, this we need to use this particular formula in order to find out pH, correct. The difference is what you see here, we have this expression, the expression is what? See the expression is Ka is equals to C alpha square by 1 minus alpha, we are having this assumption so that we can solve this expression easily. And to a certain extent, this assumption if you take, you will get a certain answer. If you don't take this assumption, then you have to solve the quadratic for alpha, and then you will get C alpha again. So in that way, the two answer that you are getting the difference is not that great. Hence we can always take this assumption, but like I said, we have a condition under which we can take this assumption, otherwise we cannot take this assumption. What is that condition I'll tell you? What you need to do? You need to find out alpha from this formula, alpha is equals to Ka by C, you just calculate the formula of alpha with this only, Ka is equals to C alpha square. So whatever question is given, you find out alpha with this formula. If the value of alpha you are getting is less than 0.1, is less than 0.1, then under this condition we can have this assumption 1 minus alpha equals to 1, right. But if the value of alpha you are getting greater than equal to 0.1, right, then we can say 1 minus alpha, we cannot assume it to be 1. In this case, you have to do the exact calculation. Exact calculation means what? You have to solve this quadratic, get the value of alpha, find C alpha, and then H plus concentration and then Ph, okay. In some book, this value they have written 0.05 as well. That also you must take care of. So this is the condition of alpha we have, under which we can take the approximation. Yes, clear understood all of you. Now we'll see this question you'll understand. First of all, all of you copy down this. Usually we use 0.1 also, 0.05 also you can take. Like, assume 0.05 only that's fine. You'll get questions in which the value won't lie in this range, because anyone you can take in mind. In some book they write 0.1, in some book they write 0.05. 0.05 you can take, not a problem. But keep this in mind, okay. Next, look at this question. Question is to calculate, calculate the Ph of 10 to the power minus 1 molar CH3 COOH solution if K value is given, K for CH3 COOH is given 2 into 10 to the power minus 5. Also calculate Ph of 10 to the power minus 5 molar CH3 COOH solution. Try this. Find out alpha first, you check whether you can neglect alpha or not depending upon its value and then use the formula accordingly. 2.85 is correct. The second one is not correct. Second one you cross check your calculation. The first one the answer is 2.85. Okay. See the first question is the first part of this question. We have concentration given that is 10 to the power minus 1 molar. K is same for both, right. So alpha is equals to what? We'll find out alpha, K by C root under. That would be 2 into 10 to the power minus 5 divided by 10 to the power minus 1 root under of it. So it is we are getting 10 to the power minus 2 into 1.414. So obviously this value is lesser than 0.05 we can say or 0.1 we can say, right. If this is there, then we can assume 1 minus alpha is almost equals to 1. And for this, the concentration of H plus we have, it is C into alpha, alpha value we have calculated. Right. So it is, or directly we can use the formula here. Both way you can solve that sort of problem. So pH is equals to half of pKa minus log C, half of pKa value is what? pKa of this is 5 minus log 2, 4.7 minus minus plus 1, 5.7 by 2. It is 2.85 the pH of the first part of this question. Okay. Obviously in the second one, if it is concentration is 10 to the power minus 5 here, this and this will get cancelled. Alpha we are getting more than one. Right. That value is to use. It means we cannot neglect alpha with respect to one. Correct. So in the second case, what we can write concentration is 10 to the power minus 5 and hence alpha value is greater than 0.1 or 0.05. Okay. So we can write H plus concentration here is C into alpha. So we need to find out the value of alpha because concentration we know 10 to the power minus 5. That formula we cannot use over here. Keep that in mind. To find out alpha what we can write kA is equals to C alpha square by 1 minus alpha. We need to solve the quadratic like I said. Yeah, 5.14 is correct I guess. Okay. So C alpha square is 10 to the power minus 5 alpha square divided by 1 minus alpha is equals to 2 into 10 to the power minus 5.  So it is 12, 12 is 2 root 3, 2 and 2 will get cancelled. So minus 1 plus root 3 and we are getting 0.732, the alpha value. This alpha will substitute here and hence the H plus concentration would be 0.732 into 10 to the power minus 5. Ph is equals to minus log of H plus. So 5 minus log of 0.732. 0.732, the value is approximately 0.14 or 0.135. So it is minus of this, it is 5.135 or 5.14. Approximately the answer is because log of 0.732 is minus of 0.135 log value is minus 0.3135 log less than one is negative log value will be given. If you cannot find out with those 34 values of log, other values will be given in the question. You don't have to worry about it. Because you cannot memorize all the log values. So if it is required, it will be given in the question. If not, then you can solve it by using some log property. Clear any doubt?


Hello people of the internet, my name is Johnny, welcome back to another video. It's been about half a month since you last heard that intro and I'm making a quick update slash vlog video to explain what I've been doing the past like half a month and most importantly what you can expect from the channel going into the new year. I don't really have any script for this video, I never tried to make a script for vlog videos and update videos which may be a bad thing cause maybe there's something I want to touch upon that I forget to mention but I'm just gonna run with it because I I do owe you guys an update even though I did make a community post though I actually don't know how well effective those things are so I'm making a video quickly before we can hop back into regularly scheduled uploads but basically I had to take a little bit of a mental break which honestly I'm very very glad I did. Usually whenever there's breaks in the upload schedule it's just because either I take too long a video or I just straight up lose motivation to make videos at that time but never do I actually take like a dedicated break I feel like this is probably the first one I had where I realized you know I told myself in my head stop focusing on uploading just focus on planning out your day relaxing enjoying a break from uploading and you know once we start to get that motivation back then we can start talking about videos going into the new year which is something I have done and something I'm pretty proud of I have basically the entire month of January planned out with videos and to be completely honest up front the first week of January is gonna be a bunch of FNAF news that I missed out on during my break I know I still need to talk about the movie castings we got a few more products a brand new wave from Funko that was leaked as well as a whole bunch of FNAF plus stuff so again that first full week of January is gonna be a bunch of catching up on news videos and I know some people can get pretty annoyed with that I get a lot of comments like this is old news why are you talking about it this is old news you know stop saying it's new news this is old news you're late you're bad which I'm exaggerating a little bit but again I do want to catch up on news that I missed cuz I owe it to you guys I mean I'm a freaking FNAF news reporter it'd be kind of dumb just to skip over it cuz oh I was on break then we don't even need to talk about it you know you know a bunch of other people have talked about it I do still want to make videos on those so just to set expectations that's gonna be like the first main week of January is gonna be catching up on news but before I keep talking about future stuff I want to quickly talk about this past year and most importantly the fact that we had 50,000 subscribers right before the year closes which was our goal for the year and I'm so so happy we were able to hit it so thank you guys so so much for the support recently it's been it's it's really helped again with losing motivation and you know mental health slowly draining towards the latter half of this year but you know getting that 50k before the year's end was really really sweet and I can't thank you guys enough for that I'm pretty proud of the year we had I think you know there was a few gaps with uploads here and there which again is a new year's resolution I'm gonna try and fix going into 2023 but other than that I'm pretty proud of the stuff we achieved a lot of awesome FNAF news videos a bunch of new series that came out including playing other games that aren't FNAF like Poppy Playtime and Choo Choo Charles and Bendy in the Dark Revival like I really do enjoy playing other horror games that aren't just FNAF and that is something I do want to do more going into we're not going into the new year but during 2023 has touched upon some other games that I like that aren't necessarily FNAF like for a very long time I've wanted to go back and play Tattletail because I freaking love Tattletail and also maybe a few granny's games maybe play Baldy every now and then I don't know we'll have to see about Hello Neighbor though I mean after seeing the reviews for Hello Neighbor 2 not really sure if we want to go play that series again but we'll see how that goes but yeah a bunch of other games I want to touch upon it for new for the new year I'm also really happy with how blocks talks has turned out so far kind of like my version of mogul male that's the inspiration behind that series which a few people caught on to but I really enjoyed talking about that you know we've got some very interesting subjects like Lego FNAF and Candyland in the cloak situation and while most of them are just kind of one-off dramas I do think if you look behind that slightly it's another way to like take a peek behind the curtains in the FNAF community see what people think about certain subjects and I think that's why I'm enjoying it a bunch so far and yes yes I know I've been talking about a follow-up to the Candyland video for quite a while now that's still in the works it's actually one of the videos I have planned for sometime this month and while we're on the topic of videos that I've talked about and haven't released yet a Halloween episode that's been a real real pain in the butt video to upload just because there are so many clips and it's such a complex topic surprisingly but just to give you a little hint my brother and I took a trip halfway across the country to that you know FNAF haunted house that took place in Ohio and that's basically our story flying out there experiencing the attraction and then also the aftermath of what happened with the place that hosted that and the drama surrounding it so it's gonna be a very interesting video again it's something I got to frickin get done because not only have I been pressuring myself to get done I've also got my brother and his friends who are trying to see it and a bunch of you guys who keep commenting commenting like where's the Halloween special it's coming also sometime this month I promise you but again I'm just really content with the videos we were able to pump out this year and I'm hoping we can go just a bit further beyond with 2023 there's a few other you know series I want to continue like I said playing other games that aren't just FNAF continuing blocks talks I'm also currently walking on getting a podcast set up with some FNAF people you may know right now we've got I don't know if I should confirm but quite a few people on board I think it's gonna be really cool I've also got an artist who's gonna be making some thumbnails for those podcast episodes and my god do they look amazing I honestly can't wait for you guys to see these thumbnails because they look fantastic her name's Rhea she's been a massive massive help with a whole bunch of art recently like I said those thumbnails for the podcast which hopefully will be coming out sometime this month that's the goal I'm not sure how frequent episodes will be I'm gonna try and aim for maybe one every week or one every two weeks but we'll have to wait and see yeah Rio's great she made a new banner for the channel she also made a design for some upcoming holiday themed merchandise which again should be launching very very soon she's absolutely fantastic please please go check her out her Instagram is gonna be linked down below and I think that's it for talking about this past year and now I know I've briefly touched upon some things I want to do for next year but just a few more nitpicks I want to do a bunch more live streams including a few charity streams every now and then I think my goal right now is to try and aim for one around mid-February kind of around Valentine's Day I also want to get back into doing game shows those FNAF game shows if you were around for Fazbear's Fortune which was admittedly just a Jeopardy ripoff it was pretty fun I really really freaking enjoyed it I want to try and get another one of those up and running because again that was a plas to work on I had so much fun during those episodes I'll probably start dipping my hand my hands my toes into shorts as well I've been doing a few every now and then for the past couple months or I guess technically the past year those absolutely pop off if you do them right and I think it's gonna be a really really good way to help us try and get to a hundred K which is gonna hopefully be the end goal for 2023 getting that silver plaque and overall I think my main new year's resolution is just to get better at scheduling not only for videos and content and streams and stuff like that but personal life too for a very very long time I've been going to bed at just the most disgusting of hours nearly 3 a.m. and waking up at like 11 sometimes even noon it's really not healthy and I think setting a personal schedule a daily schedule for myself is really gonna help out with mental health physical health and also content going to bed at reasonable hours waking up at reasonable hours working out showering and then hop into recording for a couple hours editing live streaming in the afternoon doing all that fancy YouTube stuff and then towards the later you know later part of the afternoon going in tonight just chill out take some time you know some loan time as a personal side note I've actually started to keep track of all of the shows and movies I watch which is actually making me want to watch more movies and dedicate more time to personal experiences and actually it's working out hey it's working out pretty good if I do say so myself yeah I do I've just I've fallen I've fallen in love with watching movies and consuming shows usually I wasn't that type of person because some shows can be really really freaking long and always at the back of my mind when I was watching a show I was like I could be walking on videos or I could just be like doing something productive but just taking time to yourself you know late at night getting relaxed getting ready for bed I think it's really gonna help that's a bit of a personal update and some personal goals but I think I've covered everything in this video again I do apologize for kind of disappearing though I mean I wasn't completely gone I was still posting for naff news on Twitter I'm still active in my discord which I got a new discord I guess it'll be linked down below keep in mind though the verification is pretty strict I was also on Phil's stream Visnum the fnaf plus creator that dude he did a charity stream for the Trevor project he raised like a whole bunch of money he played security breach glitchless which took like three days it was an amazing stream I was so so honored to um to be invited on that stream it's one of those things where it's like damn I will never be able to like interact with this person or I'll never be able to like you know hang out with all these people so much larger and more successful than me and then it happens and it's like how did we get here and I guess just to round out this upload this upload update video I just want to give a massive shout out to all of the creators and other influencers and just other people I've met in the industry I don't want to name off names because then I'm gonna forget people but you know who you are you mean a lot thank you so much and also thank you for watching me watching me why are you watching me also tell me about the new camera this is a new camera I don't know if there's much of a difference but I got it for for Christmas by the way I hope you all had a good Christmas or holidays whatever you know if you celebrated something different like Hanukkah or Kwanza or hey maybe you don't celebrate anything you just had a good good winter good end of the year this is going up on I think probably New Year's Eve or New Year's Day so if you have any New Year's resolutions or maybe you just want to tell me a funny story from the holidays maybe Uncle Jeb did something crazy at Christmas dinner and you got to share it with people feel free to let me know in the comments but I hope everyone's doing good and just thank you so much for sticking with me for five years of Johnny blocks and here's to yet another one but thank you so much for watching this video I can't wait to see you all for the New Year's we got a whole bunch of content and this time I'm actually motivated to do it thank you so much and I'll see you all on the flip side goodbye


Where did this whole breakfast-as-a-mouth important meal of the day concept come from? The father of public relations, Edward Bernays, infamous for his torches of freedom campaign to get women to start smoking back in the 1920s, was paid by a bacon company to popularize the emblematic bacon and eggs breakfast. The role of public relations, he wrote in his book entitled Propaganda, is the, quote, conscious and intelligent manipulation of the organized habits and opinions of the masses, unquote. Public relations specialists thereby constitute an invisible government, the true ruling power of our country. Breakfast is big business. Powerful corporate interests, such as breakfast cereal lobbying, are blamed for perpetuating myths about the importance of breakfast. This editorial in the American Journal of Clinical Nutrition urged nutrition scientists to speak truth to power and challenge conventional wisdom when necessary, even when it looks like we're taking away motherhood and apple pie. Actually, the editorial concludes, reducing the portion size of apple pie might not be a bad idea, either. So should we break the feast and skip breakfast to lose weight? The advice to eliminate breakfast will surely pit nutrition scientists against the very strong and powerful food industry. Skipping breakfast has been described as a straightforward and feasible strategy to reduce daily calorie intake. Unfortunately, it doesn't seem to work. Most randomized controlled studies of breakfast skipping found no weight loss benefit to emitting breakfast. How is it possible if skipping breakfast means skipping calories? The Bath Breakfast Project, a famous series of experiments run not out of the tub, but the University of Bath in the UK, discovered a key to the mystery. Men and women randomized to either eat breakfast, defined as taking in at least 700 calories before 11am or fast until noon every day. As in similar trials, the breakfast-eating group ate a little less throughout the rest of the day, but still ended up with hundreds of excess daily calories over the breakfast skippers. Those who ate breakfast consume more than 500 calories a day more. I mean, over six weeks that would add up to over 20,000 extra calories. Yet, after six weeks, both groups ended up with the exact same change in body fat. Wait, how could tens of thousands of calories just effectively disappear? If more calories were going in with no change in weight, there must have been more calories going out. And indeed, the breakfast group was found to spontaneously engage in more kind of light intensity physical activity in the mornings than the breakfast skipping group. Light intensity activities include things like casual walking, lighthouse-cleaning activities, not structured exercise per se, but apparently enough extra activity to use up the bulk of those excess breakfast calories. There's a popular misconception that our body goes into energy conservation mode when we skip breakfast by slowing our metabolic rate. That does not appear to be true, but maybe our body does intuitively slow us down in other ways. When we skip breakfast, our body just doesn't seem to want to move around as much. The extra activity didn't completely make up for the added calories, though. We seem to still be missing about 100 daily calories, suggesting there may be another factor to account for the mystery of the MIA morning calories. Recent breakthroughs in the field of chronobiology, the study of our body's natural rhythms, have unsuddled an even more sacred cow of nutrition, dogma, the concept that a calorie is a calorie. It's not just what we eat, but when we eat the same number of calories, different weight loss depending on meal timing. Just to give you a taste, the exact same number of calories of breakfast are significantly less fattening than the same number of calories eaten at supper. What? I mean, that's just mind-blowing, right? A diet with a bigger breakfast causes more weight loss than the same diet with a bigger dinner. Because of our circadian rhythms, morning calories don't appear to count as much as evening calories, so maybe breakfast should indeed be the most important meal of the day, after all.


Oh Technical difficulties, it's always great way a good way to get started here. I'm gonna sit this over this way a little bit so I can Walk out a little bit. Okay My name is Kyle Hudson. I'm one of the sys admins here for Baocat. The other sys admin is back here in the corner This is Adam a lot of you have of course wanted a lot with us via email and So that now you can get a face with it. This is Dave Turner He's our new guy he is our optimization application specialist person and So he's gonna be helping us out here today his voice is still a little gone We've all had colds within the last week. I've got it all through the department. I guess sir, so I I had a matter of fact yesterday My plan was to come in this morning and buy lots of pseudofed and be doped up and I woke up this morning He said hey, this isn't so bad. I think I can make it anyway, so I'm just getting over it Adam's just getting over it. They've still got it for a bit. So you know when it's down from him just In and reason is our just is our apartment head where my dad got it Look back here He's not out of town today.  He likes to be on them these things too This is I try to make this really interactive feel free to ask questions whenever through here that kind of thing If you need to drink a bathroom, they're Down here at the atrium just outside this hallway. There's some water fountains Just so the atrium and bathrooms are off to the right there. I Promise I won't be offended if you need to get up and go for any reason whatever your phone calls Somebody had one little bit of go whatever We're we're pretty flexible. We're easy-going guys. So, you know, there's point of clarification whatever Please feel free to bring it up that kind of thing We got kind of four sections here today. The first one just kind of an introduction to Linux and high-performance computing So first of all We have the section I call tools of the trade. These are what we need to get in How many of you are current Bayou cat users? Is that pretty much everybody? No, I've got a couple that aren't Well, the first thing you need Well, actually the first thing you need is to get an account Which I'm assuming the fact that you got the email that you all have an account So we're gonna skip over that part. If not get ahold of us. Yes for over this For the computer shares are just saying What Seth is a guy person to ask on this. He's a department guy. These are all department computers And and so you have to have a department login for that I'm gonna bring up a couple of them that you may or may not have known about most people know about putty So I'm most people use to get in from Windows Yes, no, maybe so yes a Few people have been using sig win. There's a new one out there called MOBA X term and I really like this going to demonstrate it for you real quick here just because I Have been rather impressed with what it does And I'm actually not gonna log into Bayou cat because I don't know my EID password I had to look it up and take me a lot longer, but I do know my CS department of password It all looks the same here. So this is MOBA X term and I I Just put a session in I could I could create a new session All I'll do is type in the username or the the name just like you would in putty Matter of fact, I'll leave an import your putty sessions if you already have putty You'll say, oh, I know what that is from putty. So you have to put anything else in there I'm gonna go here to my CS account. It says ask for my login Put in my username and my password and that brings up another one.  So I can't do that. No, I don't want to save that And the nice thing you see is over here now. Let's solve the files of stuff. I have over here. So if I have a File on my desktop See if there's any documents here No, not really Okay, I'm gonna create a file Wow save as A lot of text. Okay. Now I have a file called blood out text in my documents So here's my file. I can take MOBA X term Over here and just drag and drop this over here and I'll copy those files back and forth. So that way you have the same User interface for both Your your login that you're not switching back and forth between when SCP or file Zilla Which is why most people use to copy files in and out or SCPing files in and out You can use it all as one. You can just drag and drop straight from windows. Yes Yes, it's free if you have like more than a dozen sessions It limits you that kind of thing but for 90 I use the free version I use SSH a lot so and actually it'll also do RDP if you if you use window windows hosts So it'll it'll do a lot of different things all at once. I use this all the time Yes, I couldn't understand say it again What doesn't change say you do a find Editing a file, okay We're editing the file on on your windows Mm-hmm. Okay. Here's my When I just This wouldn't not like yeah, thank you. So edit it and put it back There it is. Yeah, so there it is You're just talking within Moba X term you've done this before I have not seen that problem Sorry, I wish I could tell you better anything better than that, but I've not seen that That's that's what I'm wondering if there's not a automatic The way that Moba X firm should do that automatically it should Download edit and then reupload again. Is there another question here? Okay So anyway, like I said, it's just a nice interface. It kind of replaces both your WinSCP and our filezilla and Putty kind of all in one All is one executable there. So like I said, I use it a lot feel free to you, you know If you go Google Moba X term, you'll find it just a helpful hand there Also on Windows like I said we mentioned filezilla and WinSCP those are our graphical interfaces to transfer files in and out We use protocols SCP and SFTP on Beocat, which is pretty common on unique systems. They're also command line based stuff if you're into the Mac world There are I don't know if there are any good graphical clients for SCP on Mac filezilla does And cyberduck is weird. I've used cyberduck and it's kind of a strange one, but it can be done But there are command line utilities if you if you're used to Linux land and it uses command line which I live About 90% of my life in command line So it doesn't bother me any but I understand that I'm unusual in that regard I've been called unusual for a lot of different reasons, but that's Not usually that reason But I do I spend most time in command line. So it doesn't bother me. You know typing commands out, but Those graphical interfaces a lot of times help How many of you guys are primarily Windows Linux or Mac? Let's try Windows big majority Mac Few Linux anybody. Oh, there are some Linux guys. All right good So actually filezilla does work on Linux also if you do like the graphical environment It's kind of a strange package it's all Probably look want to look in your distribution files for for what's there if you're if you're using on Linux But it does work and like I said if you the command line SSH and SCP do you work fine now? We do have Yeah, I mentioned a few of these are noob safe So you guys have said you primarily do Linux You're gonna be bored to death during this part because this is really really basic stuff We're talking about here. All right, or if you have any extensive experience Just just as a forewarning if you need to you know, go find some coffee or whatever. I won't be offended So most of the stuff are taken in from from this from this area This web page It's if you go to support.bayocad.ksu.edu, which most you guys probably should be fairly familiar with That is our Support wiki. We have not had anybody besides ourselves edit the wiki Anybody who's a Bayo cat user has the ability to do that if you see our documentation lacking, please update it We have no problems with this. That's why we have it out there. So have at it mention some of these things for The things I just went over Next part it gets into transferring files That's how we get our programs and our data files in and out of Bayo cat uses scp or sftp and there's examples on how to do this here on the site too I'm not gonna bore you with the details here and some basic Linux commands now So you guys that are into Linux How many of you spend much time with the command line on Linux? Some what okay a couple of concepts. We have to we're gonna try to have you understand here The first of all is a term directory That is what that's kind of analogous to the windows folder or the Mac folder. It's just a folder that holds other files for historical reasons they've always called it a directory on Unix and Linux systems and so That's the terminology we use If we're looking back to my mobex term here You can see all my all these here are my folders so I can look inside this folder and there's more files inside there That's called a directory a Shell shell is the environment that you operate under Bring up the wrong Open it up there. Okay It's an environment that you operate your commands in most by default on campus Everybody uses what's called TCSH or something C shell You know what the T that T and it is 10x C shell It used to be CSH and they came out with a better one than it's called TCSH That's the one that comes default on campus. Most people have spent much time at all using Unix and Linux have changed to bash or ZSH at this point if you there there's some Commands listed on this page on how to change that if you want to oh You we do set it for doing to bash. I didn't know we did that. Okay, so Though there's not a whole lot of difference in the way that they actually run commands It's more in the way of the way variables are handled and that kind of thing Most of most of the world uses bash SSH SSH stands for secure shell now back when I was going to school here We use telnet, which is a completely unsecured protocol That's how everybody got around everything and they realize this is a really bad idea because anybody could sniff passwords and things like that So don't use that anymore. Matter of fact, it's kind of outlawed on campus. So We use SSH SSH is secure shell. It's a fully encrypted connections. How we talk It's the It can both refer to the protocol of how you talk to it and it can refer to the program In our case MOBA X term or putty that is what we call your SSH client That's how you're talking to Bayo cat SCP is secure copy. It's a It's a part of the SSH protocol and it's allows files to be transferred in and out of Bayo cat and then the other Unix learning system your path now if I go over here To my English account and I say echo path This is going to show me all of the Areas that it's going to look for Executable files. So if I tell it to run something I have to tell it explicitly where to go unless it's in my path It's going to search through if I say run the program Boo, it's going to look for user bin boo Been boo user live JVM default Java boo So on so forth notice that the current directory is not in that list by default You have to add that Yourself if you want to be there a lot of times the best people come from Windows used to be able to have executable files in the folder that you're in and We can't do that on Linux unless we add it explicitly in here and that's to keep you from accidentally running the wrong thing Ownership every file and directory has a user group attached to it called its owners If I knew List here You'll see that all my files and folders here have a user Of Kyle Hudson and a group of Kyle Hudson users on bio cat. It's the same way by default all your files will have this ownership It affects the permissions Now the permissions will see listed over here on the side All these these RWX on everything that tells you read write and execute. So That means that for this first file, which the document that we were working on today bio cat introduction I have me being the user Kyle Hudson user has read and write access to it the Kyle Hudson users group, which I don't have anybody else in my users group except for me right now But I could add them. So they have would have read access no write access no execute access and the Last bit of three is the entire the rest of the world. So the rest of the world would have read permission No, right and no execute permission on that some useful commands here that we might these these are kind of this the sort of the basic things that we expect you to be able to navigate in in bio cat PWD is the Shows your print working directory is what it stands for so You notice I did PWD and it says homes ours home Kay Kyle Hudson. That's my home directory That's where I happen to be looking. That's where the Worm where this shell is looking at right now On bio cat when you first log in it would say homes Kyle Hudson matter of fact I'm gonna log in the okay here just to You can kind of see gotta pull out my password manager here That's right. If I can't get the password to my password manager, I don't never get in Okay, I think this is the first time I've actually typed my password dang it timed out They kind of see the difference my working director is now homes Kyle Hudson. That's a default on bio cat The LS command will list the files and and folders in the current directory and there's some switches you can put on there like Some of the more useful ones you just said I do LS by itself. That'll just give you a full list of the files, but no more information than that I Can do a LS dash LH The L means long listing H means human readable so this will tell me not only all this In permission and owner information, but it'll also tell me how big the file is in in human readable form so Like a 280 meg file here If I have that in bytes you might have to be counting how many columns there are to things like that The H is kind of handy on that The LS dash a if we look at it, that'll include all these like dot files Which are normally any file that starts with a with a period is Is not shown on a regular directory listing You can see it mo moba Exterm will show it most most clients don't show these unless you tell explicitly to do that Because these are that's how you that's basically how you hide directors because stuff normally like system files Things you don't need to worry about much so But if you do the dash a command on LS, you'll show you all of them including everything what starts with a period We have more people than seats. I'm really sorry I was truly surprised at how many people showed up for this today You know, so I use the LS command a lot just kind of see where I'm at The CD command will change directories again. We call them directories set of folders So that's why these things kind of make some sense. So I'm going to change directory to Let's find something here temp. This is a folder that I've already got out there. So say CD temp And now I do my directory listing. There's no files in that was a quick boring one. I usually have files in my temp folder. I Have there. Yeah, that's too much so I changed to another directory I changed in my rsync test directory and Here's some files that I've stuck out there. I don't even know what those were there for I'll get rid of them soon But But now when I do my directory listing my LS it shows what's in that directory not all the stuff that was up there before Because I'm just looking at that current directory along with that There are some special name directories There if you use the tilde that's brings you back to your home directory If you use a dot dot it brings you to the directory above it. So here if I do cd dot dot I go from being in my rsync test directory Back to my home directory and we got a few useful commands here that we that we use quite a bit Cat will just simply display the output of a file On the screen again, you notice that You don't have mouse control and that kind of stuff when you're in an ssh session That's not part of the ssh protocol. It won't do it even if you wanted to So you might be able to copy and paste some some text, but you're not going to be able to Actually use the mouse to interact so The the easy thing to do to get the output of a file is to use the cat cat command That'll just take the up the contents of the file and spit it out on the screen Uh cp copies of file. I'm not going to go through all these mv for move rm for for remove and then there's some uh For manipulating directories you can rm Make your remove directory that kind of thing I'm just going to refer you to this page at this point. I'm seeing lots of people looking bored here So Finding files is kind of useful sometimes too Um, again, I'm just going to kind of refer you to this so you know that it's out there When you're searching on your own desktop, you can you can install some commands that let you find things really fast When you're searching 600 terabytes of data, you take over a day to index it all and by the time you got it Done you'll be time to start the next day. That's why we don't have those tools installed on baocat So if you're looking for files To find them we're going to use the find command and here's a a uh Just some some quick examples on that Yes If you have yeah, the ls will show what's in your current directory But if you're looking for something that may be five directories levels deep and you don't know where it is That's where the find command comes in handy if you have You know you have a sub directory for this project and then you have these data files and these data files And then some sub director there finding them can be a real pain in the butt So that's why we that's why that's why you would use the find command um editing text files there's A very easy editor installed out there called nano and this is uh, we showed how to do it and Most people the way they use it is they take files and they manipulate them on their own pc And then they send them back and forth. However, if you only have a little change to make especially uh Using a text editor actually in On on baocat is a handy thing to have So let's see. I think I saw a text file there. I don't even know what's in here Oh, yeah, I don't remember doing this. Okay. I think I was actually just setting up a test using some files. I didn't care about um So here's just a text file And Get out of here I'm I'm used to using vi if you use linux on a regular basis. You're going to want to learn how to use vi It's learning curve looks about like a wall when you first start it As a matter of fact, the first question people usually have is okay. How do I get out of here? Because it's not obvious how you get out of there and everything you try doesn't work So it's a it's it's really tough to get started on once you get started on it You'll never want to go back to anything else and that's why you'll see me probably using vi for uh editing files We're going to use nano And let's just say I wanted to get rid of that first line.  The little carrots mean the control so I can say I'm going to exit with control x And I'll say do you want me to do you want to save it? yes And file name to write and by default it tells you the same thing that you already had before And apparently I didn't have permission on that file I'll say no so that's kind of Like I said, you'll you only see it in in it's the only text format stuff But most of the data people will work with is text format. So If you can if you if you have a specialty say especially small changes That's a lot useful not to have to transfer files, especially the big files Copy them back to your desktop edit them copy them back that type of thing. You can edit them straight on bio cat And like I say vi is very handy for that kind of thing too A little discussion about shells In your path ownership and permissions I've kind of gone over most of these things man pages If you need to know how to run a command If you know what the command is, but you don't know what the exact syntax is That's what man pages are for they call man. They're for the system manual So man is the command to do that the Back in the early days of unix Everything was space was at a premium. That's why they abbreviated everything. They didn't even you type the forward move It was mv you didn't type the word copy it was cp. They're everything was as short as possible So it's telling them instead of asking for the manual they'd ask for the man So they just cut it off and that's one of those things is legacy and it's stuck around forever and people still use it today Pipes and redirects. This is some pretty neat stuff um This is kind of the heart of it right there. You can take the output from A command and stick it to a file Uh do the same thing except to pin to the file You can take the instead of typing things into a command you can bring it You can send the file name to the input and you can take two commands and have the output of one go to the Input of the other you can string together lots and lots of these together if you Spend the whole lot of time on unix systems. I might have five or six of these pipes On on a single command line Just taking say the output of this take the output of this take the output of this Put them all together And one other command and it's brought up down here a little bit is grep grep is find me the contents of of Show any lines of the file that match this so like this is ls, which is showing the directory listing the grep command says Find everything that ends with dot sh. So I take the output of my ls Take that to the input of grep Which says find any find anything in what I type that that ends in dot sh But that comes from the output of the ls command and then it takes all that and it puts it into a text file So you say you're you're taking the input the input the input all stringing them all together And and putting into a single output file That's kind of a really brief introduction you could really spend Days talking about You know even basic linux stuff, but these are the kind of things that Pretty much everybody should need to know to Be able to you know When you when you ask us a question These are the things that we are going to assume that you know and if not We're gonna have to refer you to these pages and have you take a look at this yourself Okay That should be the most boring part of the day. I hope Yes question What is a shell that's the environment which it runs in In fact, we even talk about it a little bit up here There is a wikipedia page That talks about it in all sorts of great detail Yes But but it's it's kind of the way the way things are set up so it'll run commands That's that's the the interactive environment that you're under But it does take a lot of time


Hello, everyone. My name is Fan Wu. I'm a software engineer at Microsoft. My work is code integrity both on Linux and Windows. In this talk, I'm going to talk about code integrity in Linux. Code integrity essentially is when we try to use a file, we guarantee the file is not modified by an attacker. To give some background here, my coworker Devon proposed an LSM called IP last year. The feedback from the upstream was they wanted us to try to implement the features of IP into IMA. I will present the current progress of the investigation. We will have a brief introduction to our design motivation and what is IP. Then followed by the features of IP, we added it to IMA. Then followed with the discussion. We are trying to build a security system for fixed function machines. For example, network firewall device in a data center or an IoT device like smartwatch machine. This device don't need frequent update and can be completely locked down, so we can provide a high-level security guarantee. Other than the security part, we also want to have a high-level availability, so we don't want to reboot the machine. Also, we want the failure can be easily diagnosable, such that as long as we see the lock, we know where is the problem inside the system. Finally, the hardware resources for such kind of devices are limited, like small RAM sites, which means it will incur more disk risk and may lose more tax. Here's our threat model. We want to let our system can protect the integrity of files in the user space. Specifically, we want to protect the executable binaries and configuration files. The attacker can have the access of the machine locally or remotely as a user. The attacker can also be a compromised malicious block device, which can send arbitrary malicious data to the kernel. Some attacks are out of scope. When the kernel is compromised, the security system can be just bypassed, so there's no security guarantee. Or the memory can be directly modified, then the attacker can almost run anything. Here's a brief introduction to IPE. IPE is a Linux security module, like SC Linux, up armor. It provides a policy to control the system-wide coding integrity requirement and the enforcement. It only do one thing that is coding integrity. It completely decoupled the policy and the mechanism. IPE itself only provides policy enforcement. All the actual integrity mechanisms are provided by the other kernel components. Essentially, this means what IPE do is it's just a law or denied file based on the file context that contains what kind of security or the integrity mechanism are used to protect the file. For now, IPE supports DM variety and FS variety. New mechanisms can be easily supported because IPE has a modular design. IPE also has a flexible policy syntax and the comprehensive policy control interfaces. IPE has a swapable reboot-less policy, which means we can deploy multiple different policies at the same time and switch to whatever we want to use without any reboot. IMA has a place for code integrity, but some features are missing. The highlighted are the subset of features of IPE we tried to add to IMA. Starting from here, we are going to talk about the details of the missing features of IMA. The first thing is granularity. We think the granularity for large and small units are both important. But IMA only supports file-level granularity. It has no support for whole block device, which can make the deployment process complicated. The second thing is the whole file needs to be measured before a praise. Measure here means to read the whole file content, then hash it and use that hash as the feature of the file. This will incur a very noticeable latency increase for large files because the whole file needs to be read from the disk. It cannot verify the file integrity if the file is not opened with read permission. This is essentially a system layering issue. What caused this problem is because IMA operates on the security system level, which is above the file system. To read the file content, it has to interact with the file system. So if the file is not opened with the read permission from the user space, then the IMA cannot be allowed by the file system to read the file's content. The most critical issue is IMA can be cheated by malicious block devices. There's a paper published last year detailed the actual attack. In short, if we have a very big file that cannot fit into the memory, at the measurement process, the attacker can send a good file content to the IMA, and IMA will think the file is a good file. Then, because the file cannot fit into the memory, when the user wants to use the file, it has to read the file content from the block device again. At this time, the block device can send arbitrary malicious data to the kernel, such that the user can be attacked. Again, this is because IMA is above the file system level, so it cannot do the integrity check on every disk operation. Then it's the policy syntax issue. Essentially, policy cannot make a law or deny decision on its own. For example, there's a praise rule here, and this will be applied to all files when it is used by MAP with execution permission. If the rule is applied to a file, after the policy evaluation, IMA cannot make the decision of allow or deny the use of the file. It will ask other parts of the IMA to compare the file hash against a pre-computed hash, then make the decision. This is also a result of coupling of policy and mechanism. The solution here we propose is to utilize DM variety, make IMA just like IPE to delegate the actual integrity mechanism to DM variety instead on its own. The benefit here we get is we will have a significantly smaller read latency overhead thanks to the hash tree of DM variety. Also, by using DM variety, it can also avoid IMA interacts with the file system. This is because the actual integrity protection is dedicated to the DM variety, and the DM variety is operated on the block device level, which will do the actual verification on every disk operation. We also added two new pre-type to let the policy can make the allow or deny decision in the policy. Here's the actual implementation of the DM variety support for IMA. First, we added a new security block device such that we can save some DM variety metadata, like the root hash or the signature. During the policy evaluation, IMA can make the allow or deny decision based on these metadata. Then we added two new policy conditions for DM variety. This gives the policy the ability to specify which DM variety volume is allowed to be used. Finally, we added two new appraised type, which gives the policy the ability to make the allow or deny decision. Here, the first one appraised type equals DM variety, where allow files from a DM variety volume to be used if the DM variety condition rules are satisfied. The parcel will make sure if this appraised type is used, there must be some DM variety rule conditions inside the rule. The second one appraised type equals deny will deny files if the rule condition can be satisfied. At the bottom, we give two examples of policy rules to allow files to be used from a specified DM variety. The first one will allow files to be M-mapped if it is from a signed DM variety volume. The second one will allow files to be M-mapped if the volume hash matches with the hash inside the rule condition. Then we move on to the IMA policy control limitations. The first thing is IMA has limited policy interfaces. Only one policy can be deployed. It is impossible to deploy multiple independent policies. For features like use different policies for different containers, it is hard to implement for the current IMA. The second thing is the deployed policy cannot be deleted without a reboot. Sometimes our policy need to be updated or deleted. Because IMA need to reboot the machine to delete the policy rules, it will greatly impact our availability time. It has no permissive switch. IMA doesn't have a permissive switch that is available in SELinux and IPE. This feature is extremely useful for designing and experimenting new policies. The second thing is IMA doesn't have a full control of deployed policy rules. In some cases, it will implicitly add some rules that has higher priority than the user deployed rules. This could be problematic if the implicit rules are causing the problem to the system. And because these rules cannot be deleted without changing the source code, we have to figure out the way to solve this issue. Finally, IMA uses itself to verify the integrity of the policy file, which can be affected by multiple factors like the IMA keyrings, like the extended attributes, or the block list. We think using other mechanisms will be better to verify the integrity of the policy. So the solution of our extension is we added a new kernel structure to track the deployed policy states, like the policy flex, so that we can deploy multiple different policies. We extended the security file system such that we can deploy multiple policies and manage them. We added a kernel switch to remove the implicitly deployed policy rules. We utilized the PKC7 to verify the policy integrity against the kernel trusted keyring instead of IMA's own keyrings. We introduced a permissive switch for IMA to switch to the permissive mode. Here is the actual implementation of the new control interfaces prototype for IMA. First, we created a new structure to encapsulate the policy. The encapsulation of policy won't break any existing IMA features. The structure will be used to track policy flex for each policy. Previously, IMA uses many global variables for these policy flex, but now we have multiple policies. We need to have a structure to track the different policies. We added a new policy attributes, saved them inside a new policy structure. For example, we can have some policy versions inside the policy structure such that we can prevent anti- rowback attack. Here, the anti-rowback means we can prevent all the policy overwrite the new policies. Because we have multiple policies now, we need to have a name for each policy. We extended the policy syntax such that we added a new action called policy and the new condition rules called policy name to assign each policy name. Then we changed the policy management interfaces. We created a new file inside the security file system such that we can deploy the policy by the PKC7. We also created a new folder inside the security file system so that such that the administrator can manage the policies. And because we have multiple policies now, we added a new pointer which is protected by the RCU. That will point to the policy structure currently active. We guarantee only one policy will be active at the time. Finally, we introduced the permissive switch inside the security file system such that that is protected by the memory barriers just like what is implemented in SNLinux and IPE. And here we have a demo. We will run two binaries. One is GCC, which is not inside the DRM variety of volume. One is Halloword, which is inside the DRM variety of volume. And we will try different policies and see the behavior of the system. So here we see we have mounted a DRM variety of volume inside the TEMP file system. That is TEMP IP test. Then we switch to the policy management folder inside the IMA security file system. And there's only default policy deployed. And we can see the content inside. There's no appraisal inside. So everything will be allowed to be executed. Now we will switch to a folder that contains the policy and use cat to write the policy content to the security file system node. And we can see we have deployed three policies. Then we will try to activate the first policy which will allow the execution of binaries from a specific DRM variety, which is specified by the DRM variety root hash. Then we first see the content inside. You can see we have the new rules and the new appraised types. And then we try to activate this policy and try to use GCC failed because it is not from a DRM variety volume. Then use password and succeed. Then we will try to get into the permissive mode such that we can use the cat to see the content of other policies. Here for the second one, that will allow the use of a DRM variety volume that is signed by a trusted certificate. Now we try to activate this policy. Now the policy is activated. And we also need to set the enforcement mode. Then GCC failed because it is not inside the DRM variety volume. Then password succeed. So then the final case is the revocation case. In some cases we want to revoke the use of a specific DRM variety volume. And here the policy will deny the use of files from a specific DRM variety volume specified by the root hash. And we can see the content of this policy. Then we try to activate this policy. Also we need to turn on the enforcement mode. Then GCC succeed because it is not in the DRM variety volume. And password denied because it is inside the DRM variety. From here we are going to talk about the IMA extending difficulties and its fundamental limitations. The first problem is IMA measure strongly coupled with a praise. Because IMA has multiple actions, every policy evaluation needs to iterate the whole policy to cover all possible actions. This can be inefficient if the policy only contains one action like a praise. While for IPE, it focuses only on coding integrity. It will make the decision once it finds the first applicable rules inside the policy, which means IPE is more efficient for policy evaluation. The above coupling also causes the IMA policy mechanism or evaluation result to be a bitmap, which contains IMA actions with their parameters. Currently the bitmap has 32 bits. And while with our extension to IMA, 30 bits are using, if only two bits available for the future features. This is not really scalable and can be problematic for new upcoming features. While IPE doesn't have such an issue because the evaluation of IPE policy is just allow or deny the file. All IMA actions happen inside one single function that is process measurement. Extending a praise will make this function more complex and may cause regression to other actions. The second problem is IMA's coding integrity deployment process is complicated. Not only in policy need to be deployed, but the broad-list extended attribute and keyrings are also need to be configured. While for IPE, all you need to do is just to deploy the policy then all set. The final problem is IMA policy heavily coupled with its mechanism. IMA praise decision cannot solely be determined by the policy. It will be affected by the other factors as we just showed. And because the policy cannot fully control the system behavior, this will be headache for the administrators to travel through the machine when failures happen. And more importantly, as we mentioned previously, IMA existing integrity mechanism can be treated by malicious block device. This makes us less likely to use the existing integrity mechanism of IMA. Finally, from our experience of extending IMA, we found it is very hard to extend it for new integrity mechanism. We need to add multiple new IMA flags at different parts of IMA, which is very hard to figure out and hard to maintain the code. Meanwhile, IPE has a modular design. If we want to add a new support for a new mechanism, we just need to add a new single file. And other parts, we don't need to touch the other parts. Then we start the discussions. Here are some facts. As far as we are aware, IMA doesn't have a comprehensive test for appraise. Continue to extend appraise may break the existing features. And because we don't have the test, we don't know what kind of change will break the features. This makes us afraid of continuing to extend it. Microsoft is still using IPE in our internal production system on a daily basis. We're using IPE and IMA simultaneously, but IPE only for code integrity and IMA only for measurement. As we discussed before, the security system level is not ideal for integrity mechanism as it can be easily detected. DM variety, which is in the block device level and FS variety, which is in the file system level, are two good examples of good code integrity mechanisms. The original design of IMA is on top of the action measure, which calculates the file hash before the praise. This essentially means IMA has to do the measurement before the praise every time. However, the measurement is no longer prerequisite for coding integrity. This can be simply proved by the implementation of IPE. We did nothing related to measurement, but still guarantee the system with code integrity. Moreover, if the IPE and IMA are both enabled due to the LSM stacking, if the IPE denies a file, then the IMA's measurement hook won't be triggered. This can let us avoid some useless measurements actions. IPE is perfectly adhering Linux keys principle, which only do one thing, that is code integrity, and do it well. As measurement and code integrity can be totally separate kernel module, we think it should be better to let them separately operating. The prototype the feature to IMA are only a small subset of IPEs. We also support FS variety. We support trust files in Ethereum FS. We support anonymous memory verification. We also have a comprehensive test suite that covers various attack scenarios. The most excited part is the namespace support that will be present by my co-worker Devon this afternoon. This essentially means we can have multiple containers that has different policy deployed and operates cooperatively. Thank you for listening. I'm ready for take any question. Okay, so basically the problem is what kind of the actual mechanism of the coding integrity provided by IMA, right? They will save the pre-computed hash inside the extended attribute of the file system and may sign the hash. And it will configure a key ring of what kind of the certificate to be trust that sign the hash. And also they will have a block test that will just block the file based on the hash. These are the features as far as I know. I think I repeat the question. So the question is the existing coding integrity features of IMA already inside the system. Any else? Okay, I think we are done here. Thank you for listening.


Happy 2019! Hey there saplings! Welcome back to esoteric moment! I am so excited to usher in a new year and I wanted to share some of the things I'm doing to bring a little bit more magic into this time period with you. Many druids in those following a Catholic path will say that new year for the like wheel of the year starts at Salon, but for me that's never quite felt right. The dark part of the year is all about like cleaning out and connecting to ancestors and like making space and that feels very much a part of the old year, not the new year. So my new year in the wheel of the year is definitely at winter solstice, yule, and it ties in really well with energy of the mundane world around us as you're celebrating the calendar new year. So between the time period of winter solstice to new years, I like to make a lot of intentions, magic setting, and space for just a really great year ahead of me. One of the keys to my magical new years is making sure that I set some time for just me to be alone on yule. I definitely take the day off from work and I make sure that on that day I have at least a couple hours where I can sit in a quiet room with some tea and really make space for myself and not get wrapped up in the holiday extravaganza that is all around. One of the things I like to do is to kind of communicate and have a conversation with the spirit of yule as I like to call it. That darkness, that stillness that we're really honoring on yule in all the excitement of the return of the sun is something that is really important to me. I like to kind of close out the year by letting go of whatever wasn't working in the previous year in 2018 and talking about what's going to work for 2019. I sometimes have this conversation with the spirit of yule allowed and sometimes I write it down in a journal just depending on whatever works best for me that year. I also do a little bit of divination. It's pretty common for many folks to kind of look at the year coming up and I do this with drawing a tarot card for each month of the coming year and then I write that down in my planner so I can refer back to it as each month comes around. Once I kind of get a feel for what's coming up I dive into my core desired feelings. I'm not going to share all of them with you just yet but one of the things I'm really working on for 2019 is flow. It's so easy for me to get wrapped up in planning and prepping and trying to get ahead of things that I forget to enjoy the moment so 2019 is all about letting each moment flow into the next being okay with that, being okay with not having everything prepared and just letting the joy and delight happen without pushing it or trying to direct it so much. Core desired feelings are a really great way to tap into how you want to feel and so when you make goals or intentions it all comes back to that feeling rather than external objectives that like the community your family or what you think you should be putting on yourself. There are lots of ways that we can feel that dream life without necessarily pushing ourselves to the extreme rat race that we feel so often in our mundane and everyday life. I try to get all of this done at Yule if it doesn't happen I have until new years to kind of work on this and to do these elements that really helped me bring in the magic of this season. I also do a lot of work in my planner. I have a Midori Traveler's Notebook style it's like an A5 size. I'm sticking with the bullet journal style again for this year but it is heavily influenced by some of my other favorite planners like Daniela Port's planner and some other things I've seen online. The nice thing about keeping my planner with my journal and work notes is that everything is really condensed and I'm not carrying around a million things. I love the feel of it and it's definitely Midori is where it's at for me. I love that style and how adaptable it can be for me each year. The keys to a magical new year for me is really about making space for myself finding ways to like honor and respect this seed and germination time that we have before the new year comes in. I love the darkness and the quiet and the peacefulness and just like the love that we can really generate as a community and in our own lives at this time. Sometimes it is hard like I don't want to downplay the tensions and stress that holidays can bring on everyone and I really hope that you can find some moments to feel something other than stress and anxiety during this time period and give yourself the space to germinate all the great things you hope to bring into 2019 for yourself. Let me know in the comments below what your core desired feelings or intentions for 2019 are. I am very curious. This week's Sapling Shoutout goes out to Zayn Cooper on Instagram. I put a post about some of the myths and things that bring inspiration and owen to my practice and he wrote a really awesome comment talking about his family and the myths that inspire his practice. If you want to be a Sapling Shoutout definitely talk to me in the comments here on YouTube or over on Instagram. That is where I'm hanging out the most and I love talking and hanging out with you guys and learning from you. Hope you guys have a wonderful 2019. Thank you for watching and as always may you find peace in the sacred groves.