Re: [CMake] How URL_MD5 is computed in ExternalProject_Add?
I managed to obtain the same MD5 code by running the md5sum command on the downloaded file. However, I would like to write an automatic way of downloading third-party libraries. Is it possible to let CMake compute the MD5 of the downloaded file? Cédric - Mail original - De: Cedric Doucet cedric.dou...@inria.fr À: cmake@cmake.org Envoyé: Mardi 19 Mai 2015 12:37:03 Objet: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake-- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
[CMake] How URL_MD5 is computed in ExternalProject_Add?
Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
Re: [CMake] How URL_MD5 is computed in ExternalProject_Add?
You can use FILE (MD5 file variable) command to compute MD5 value. From: CMake on behalf of Cedric Doucet Date: Tuesday 19 May 2015 13:14 To: cmake@cmake.orgmailto:cmake@cmake.org Subject: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? I managed to obtain the same MD5 code by running the md5sum command on the downloaded file. However, I would like to write an automatic way of downloading third-party libraries. Is it possible to let CMake compute the MD5 of the downloaded file? Cédric De: Cedric Doucet cedric.dou...@inria.frmailto:cedric.dou...@inria.fr À: cmake@cmake.orgmailto:cmake@cmake.org Envoyé: Mardi 19 Mai 2015 12:37:03 Objet: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
Re: [CMake] How URL_MD5 is computed in ExternalProject_Add?
... And thank you very much for your help Marc! :) - Mail original - De: Cedric Doucet cedric.dou...@inria.fr À: David Cole dlrd...@aol.com Cc: cmake@cmake.org Envoyé: Mardi 19 Mai 2015 15:38:49 Objet: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello David, I understand exactly what you mean but the misunderstanding comes from your sentence: The point is to double check that it downloaded correctly and as expected. That's NOT why I use the URL_MD5 variable in ExternalProject_Add. I use it to avoid downloading again libraries after typing 'make clean'. So, my feeling is that I shouldn't use the URL_MD5 variable to perform this checking. Furthermore, I should check other steps (updating, configuration, building, installation). Do you agree with this? What is the correct way to do this with CMake? Cédric - Mail original - De: David Cole dlrd...@aol.com À: Marc CHEVRIER marc.chevr...@sap.com Cc: Cedric Doucet cedric.dou...@inria.fr, cmake@cmake.org Envoyé: Mardi 19 Mai 2015 15:04:58 Objet: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? The point of specifying URL_MD5 in ExternalProject_Add is so that it can check to see if it downloaded the file properly. If you don't tell it what the md5 sum should be, then what good is computing it after downloading it? The point is to double check that it downloaded correctly and as expected. If you don't tell it what to expect, it's impossible. So... you can't download arbitrary content from the internet unless you can also download it's corresponding md5 sum reliably. But... you can't even do that: because if somebody is trying to spoof it and hacks the file on the internet, they can just as easily hack the md5 you'd get from the internet and fool you into using a hacked file. So: it's up to you to verify that a package retrieved from the internet is use-able and un-hacked, and then computes its md5 sum (or even better, SHA-1 sum), and pass it to ExternalProject_Add so it can *fail* if the sum of the downloaded file does not match the expected sum. Does this make sense? On Tue, May 19, 2015 at 7:29 AM, CHEVRIER, Marc marc.chevr...@sap.com wrote: You can use FILE (MD5 file variable) command to compute MD5 value. From: CMake on behalf of Cedric Doucet Date: Tuesday 19 May 2015 13:14 To: cmake@cmake.org Subject: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? I managed to obtain the same MD5 code by running the md5sum command on the downloaded file. However, I would like to write an automatic way of downloading third-party libraries. Is it possible to let CMake compute the MD5 of the downloaded file? Cédric De: Cedric Doucet cedric.dou...@inria.fr À: cmake@cmake.org Envoyé: Mardi 19 Mai 2015 12:37:03 Objet: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http
Re: [CMake] How URL_MD5 is computed in ExternalProject_Add?
Hello David, I understand exactly what you mean but the misunderstanding comes from your sentence: The point is to double check that it downloaded correctly and as expected. That's NOT why I use the URL_MD5 variable in ExternalProject_Add. I use it to avoid downloading again libraries after typing 'make clean'. So, my feeling is that I shouldn't use the URL_MD5 variable to perform this checking. Furthermore, I should check other steps (updating, configuration, building, installation). Do you agree with this? What is the correct way to do this with CMake? Cédric - Mail original - De: David Cole dlrd...@aol.com À: Marc CHEVRIER marc.chevr...@sap.com Cc: Cedric Doucet cedric.dou...@inria.fr, cmake@cmake.org Envoyé: Mardi 19 Mai 2015 15:04:58 Objet: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? The point of specifying URL_MD5 in ExternalProject_Add is so that it can check to see if it downloaded the file properly. If you don't tell it what the md5 sum should be, then what good is computing it after downloading it? The point is to double check that it downloaded correctly and as expected. If you don't tell it what to expect, it's impossible. So... you can't download arbitrary content from the internet unless you can also download it's corresponding md5 sum reliably. But... you can't even do that: because if somebody is trying to spoof it and hacks the file on the internet, they can just as easily hack the md5 you'd get from the internet and fool you into using a hacked file. So: it's up to you to verify that a package retrieved from the internet is use-able and un-hacked, and then computes its md5 sum (or even better, SHA-1 sum), and pass it to ExternalProject_Add so it can *fail* if the sum of the downloaded file does not match the expected sum. Does this make sense? On Tue, May 19, 2015 at 7:29 AM, CHEVRIER, Marc marc.chevr...@sap.com wrote: You can use FILE (MD5 file variable) command to compute MD5 value. From: CMake on behalf of Cedric Doucet Date: Tuesday 19 May 2015 13:14 To: cmake@cmake.org Subject: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? I managed to obtain the same MD5 code by running the md5sum command on the downloaded file. However, I would like to write an automatic way of downloading third-party libraries. Is it possible to let CMake compute the MD5 of the downloaded file? Cédric De: Cedric Doucet cedric.dou...@inria.fr À: cmake@cmake.org Envoyé: Mardi 19 Mai 2015 12:37:03 Objet: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow
Re: [CMake] How URL_MD5 is computed in ExternalProject_Add?
The point of specifying URL_MD5 in ExternalProject_Add is so that it can check to see if it downloaded the file properly. If you don't tell it what the md5 sum should be, then what good is computing it after downloading it? The point is to double check that it downloaded correctly and as expected. If you don't tell it what to expect, it's impossible. So... you can't download arbitrary content from the internet unless you can also download it's corresponding md5 sum reliably. But... you can't even do that: because if somebody is trying to spoof it and hacks the file on the internet, they can just as easily hack the md5 you'd get from the internet and fool you into using a hacked file. So: it's up to you to verify that a package retrieved from the internet is use-able and un-hacked, and then computes its md5 sum (or even better, SHA-1 sum), and pass it to ExternalProject_Add so it can *fail* if the sum of the downloaded file does not match the expected sum. Does this make sense? On Tue, May 19, 2015 at 7:29 AM, CHEVRIER, Marc marc.chevr...@sap.com wrote: You can use FILE (MD5 file variable) command to compute MD5 value. From: CMake on behalf of Cedric Doucet Date: Tuesday 19 May 2015 13:14 To: cmake@cmake.org Subject: Re: [CMake] How URL_MD5 is computed in ExternalProject_Add? I managed to obtain the same MD5 code by running the md5sum command on the downloaded file. However, I would like to write an automatic way of downloading third-party libraries. Is it possible to let CMake compute the MD5 of the downloaded file? Cédric De: Cedric Doucet cedric.dou...@inria.fr À: cmake@cmake.org Envoyé: Mardi 19 Mai 2015 12:37:03 Objet: [CMake] How URL_MD5 is computed in ExternalProject_Add? Hello, I use the URL_MD5 variable to avoid downloading more than once a library with the ExternalProject_Add command. However, I don't manage to get the same MD5 code as CMake when I try to get one with generators available on the internet. How could I get the same one for an URL written in the form http://www.mywebsite.myext/mypath/myfile? I have already tried the MD5 of the URL and of myfile but I don't get the same MD5 as CMake. Thanks! Cédric -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
