No download over HTTPS

[Stefan K.]

zsync cannot download the target file, if it is requested by HTTPS.

It just says the remote file cannot be found as if you have defined an invalid URI.

This happens for example if you get isos from a mirror like

https://ftp.halifax.rwth-aachen.de/ubuntu-releases/18.04.1

Change it to http in cmdline or the "URL" line in zsync file and it works fine.

zsync 0.6.2-1ubuntu1
DISTRIB_ID=neon
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="KDE neon User Edition 5.13"

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[shemgp (shemgp)]

On groovy here and I can't update https://releases.ubuntu.com/20.04/ubuntu-20.04.1-live-server-amd64.iso.zsync using zsync. Had to change it to: http://releases.ubuntu.com/20.04/ubuntu-20.04.1-live-server-amd64.iso.zsync.

strace zsync https://releases.ubuntu.com/20.04/ubuntu-20.04.1-live-server-amd64.iso.zsync
execve("/usr/bin/zsync", ["zsync", "https://releases.ubuntu.com/20.0"...], 0x7fff19f68278 /* 73 vars */) = 0
brk(NULL) = 0x564ac4377000
arch_prctl(0x3001 /* ARCH_??? */, 0x7fff829439d0) = -1 EINVAL (Invalid argument)
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=357046, ...}) = 0
mmap(NULL, 357046, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fb90df4f000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\360q\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0o\340p\t\274W\346\221p0\320R7\r\213\355"..., 68, 880) = 68
fstat(3, {st_mode=S_IFREG|0755, st_size=2029224, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fb90df4d000
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
pread64(3, "\4\0\0\0\20\0\0\0\5\0\0\0GNU\0\2\0\0\300\4\0\0\0\3\0\0\0\0\0\0\0", 32, 848) = 32
pread64(3, "\4\0\0\0\24\0\0\0\3\0\0\0GNU\0o\340p\t\274W\346\221p0\320R7\r\213\355"..., 68, 880) = 68
mmap(NULL, 2036952, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fb90dd5b000
mprotect(0x7fb90dd80000, 1847296, PROT_NONE) = 0
mmap(0x7fb90dd80000, 1540096, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x25000) = 0x7fb90dd80000
mmap(0x7fb90def8000, 303104, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19d000) = 0x7fb90def8000
mmap(0x7fb90df43000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7fb90df43000
mmap(0x7fb90df49000, 13528, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fb90df49000
close(3) = 0
arch_prctl(ARCH_SET_FS, 0x7fb90df4e580) = 0
mprotect(0x7fb90df43000, 12288, PROT_READ) = 0
mprotect(0x564ac40c2000, 4096, PROT_READ) = 0
mprotect(0x7fb90dfd4000, 4096, PROT_READ) = 0
munmap(0x7fb90df4f000, 357046) = 0
getpid() = 169401
brk(NULL) = 0x564ac4377000
brk(0x564ac4398000) = 0x564ac4398000
openat(AT_FDCWD, "https://releases.ubuntu.com/20.04/ubuntu-20.04.1-live-server-amd64.iso.zsync", O_RDONLY) = -1 ENOENT (No such file or directory)
write(2, "failed on url https://releases.u"..., 91failed on url https://releases.ubuntu.com/20.04/ubuntu-20.04.1-live-server-amd64.iso.zsync
) = 91
write(2, "could not read control file from"..., 114could not read control file from URL https://releases.ubuntu.com/20.04/ubuntu-2...

[Ubfan (ubfan1)]

Oct 23, on an ubuntu 18.04 system, the Ubuntu 20.10 zsync download displays the above errors when an https download is attempted. Using http succeeds.

The failure (local iso is a renamed beta):
$ zsync -i ubuntu-20.10-desktop-amd64.iso https://releases.ubuntu.com/20.10/ubuntu-20.10-desktop-amd64.iso.zsync
failed on url https://releases.ubuntu.com/20.10/ubuntu-20.10-desktop-amd64.iso.zsync
could not read control file from URL https://releases.ubuntu.com/20.10/ubuntu-20.10-desktop-amd64.iso.zsync

[shemgp (shemgp)]

Still present in current jammy.