normal world CA is hanging at getentropy( ) syscall

[nageshshamnur]

Hi,
I am running openssl in CA application and do the test on QEMU default environment (QEMU v7). Version of optee used is 3.6.0.

When my CA application invokes SSL_CTX_new( ), it hangs at RAND_bytes( ), analysing the call stack revealed that syscall to getentropy( ) function at UNIX blocked. Callstack as below:

3004 if ((RAND_bytes(ret->ext.tick_key_name,
(gdb)

^C
Program received signal SIGINT, Interrupt.
__libc_do_syscall () at ../sysdeps/unix/sysv/linux/arm/libc-do-syscall.S:46
46 swi 0x0
(gdb) bt
#0 _libc_do_syscall () at ../sysdeps/unix/sysv/linux/arm/libc-do-syscall.S:46
#1 0x76b4abe6 in getentropy (buffer=0x3a778, length=) at ../sysdeps/unix/sysv/linux/getentropy.c:45
#2 0x76e1dec8 in syscall_random (buf=0x3a778, buflen=32) at crypto/rand/rand_unix.c:324
#3 0x76e1e5d4 in rand_pool_acquire_entropy (pool=0x3a750) at crypto/rand/rand_unix.c:589
#4 0x76e1c590 in rand_drbg_get_entropy (drbg=0x3a508, pout=0x7efffb44, entropy=256, min_len=32, max_len=2147483647, prediction_resistance=0) at crypto/rand/rand_lib.c:198
#5 0x76e1a964 in RAND_DRBG_instantiate (drbg=0x3a508, pers=0x76eef35c <ossl_pers_string> "OpenSSL NIST SP 800-90A DRBG", perslen=28) at crypto/rand/drbg_lib.c:338
#6 0x76e1bbac in drbg_setup (parent=0x0) at crypto/rand/drbg_lib.c:895
#7 0x76e1bc80 in do_rand_drbg_init () at crypto/rand/drbg_lib.c:924
#8 0x76e1bbe8 in do_rand_drbg_init_ossl () at crypto/rand/drbg_lib.c:909
#9 0x76c5988e in pthread_once_slow (once_control=0x76f26f8c <rand_drbg_init>, init_routine=0x76e1bbdc <do_rand_drbg_init_ossl>) at pthread_once.c:116
#10 0x76e63370 in CRYPTO_THREAD_run_once (once=0x76f26f8c <rand_drbg_init>, init=0x76e1bbdc <do_rand_drbg_init_ossl>) at crypto/threads_pthread.c:118
#11 0x76e1c164 in RAND_DRBG_get0_public () at crypto/rand/drbg_lib.c:1116
#12 0x76e1be18 in drbg_bytes (out=0x39e38 "", count=16) at crypto/rand/drbg_lib.c:966
#13 0x76e1ddb4 in RAND_bytes (buf=0x39e38 "", num=16) at crypto/rand/rand_lib.c:938
#14 0x76f687c8 in SSL_CTX_new (meth=0x76fcfef0 <TLS_server_method_data.26172>) at ssl/ssl_lib.c:3004
#15 0x00012878 in server_create_context () at test/src/vpp_openssl_adpt_server.c:75
#16 0x00012b64 in tls12_server () at test/src/vpp_openssl_adpt_server.c:169
#17 0x00012ccc in main () at test/src/vpp_openssl_adpt_server.c:215

[vivinamartins16]

I get the same problem!
I can't even get curl to work with https. Any help with this would be much appreciated :)

[jforissier]

It looks like the guest doesn't have enough entropy. Please try enabling the VirtIORNG device, see here: https://wiki.qemu.org/Features/VirtIORNG
(Note: there is a QEMU parameter plus a command in the guest)