The above was an FYI, but is should be fine as outlined by Lazlo this isn't needed as since ipxe 1.0.0+git-20180124.fbe8c52d-0ubuntu4 we use CONFIG=qemu and in comment #7 he explained that in this case "totally don't need (or even *use*) the iPXE HTTPS infrastructure (the entropy gathering that trips the ASSERT seems spurious to me, with CONFIG=qemu). With CONFIG=qemu, iPXE provides the UEFI SNP (Simple Network Protocol) interface on top of the e1000 NIC, and the crypto stuff (if any) is done by the platform firmware (edk2 / OVMF)"
The above was an FYI, but is should be fine as outlined by Lazlo this isn't needed as since ipxe 1.0.0+git- 20180124. fbe8c52d- 0ubuntu4 we use CONFIG=qemu and in comment #7 he explained that in this case "totally don't need (or even *use*) the iPXE HTTPS infrastructure (the entropy gathering that trips the ASSERT seems spurious to me, with CONFIG=qemu). With CONFIG=qemu, iPXE provides the UEFI SNP (Simple Network Protocol) interface on top of the e1000 NIC, and the crypto stuff (if any) is done by the platform firmware (edk2 / OVMF)"