*Hi! I am learning how to use Linux Crypto API.I used the following code with success with .salg_type = "skcipher", .salg_name = "cbc(aes)"However with "aead"/"gcm(aes)" sendmsg fails as below.What is wrong? Great thanks,I looked into documentation but could not figure out what was wrong
{ int opfd; int tfmfd; struct sockaddr_alg sa = { .salg_family = AF_ALG, .salg_type = "aead", .salg_name = "gcm(aes)" }; struct msghdr msg = {}; struct cmsghdr *cmsg; char cbuf[CMSG_SPACE(4) + CMSG_SPACE(20)] = {0}; char buf[16]; struct af_alg_iv *iv; struct iovec iov; tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0); bind(tfmfd, (struct sockaddr *)&sa, sizeof(sa)); setsockopt(tfmfd, SOL_ALG, ALG_SET_KEY, "\x06\xa9\x21\x40\x36\xb8\xa1\x5b\x51\x2e\x03\xd5\x34\x12\x00\x06", 16)); opfd = accept(tfmfd, NULL, 0); msg.msg_control = cbuf; msg.msg_controllen = sizeof(cbuf); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = SOL_ALG; cmsg->cmsg_type = ALG_SET_OP; cmsg->cmsg_len = CMSG_LEN(4); *(__u32 *)CMSG_DATA(cmsg) = ALG_OP_ENCRYPT; cmsg = CMSG_NXTHDR(&msg, cmsg); cmsg->cmsg_level = SOL_ALG; cmsg->cmsg_type = ALG_SET_IV; cmsg->cmsg_len = CMSG_LEN(20); iv = (void *)CMSG_DATA(cmsg); iv->ivlen = 16; memcpy(iv->iv, "\x3d\xaf\xba\x42\x9d\x9e\xb4\x30\xb4\x22\xda\x80\x2c\x9f\xac\x41", 16); iov.iov_base = "Single block msg"; iov.iov_len = 16; msg.msg_iov = &iov; msg.msg_iovlen = 1; if(-1 == sendmsg(opfd, &msg, 0)) { //errno is 22 (Invalid argument) }}