On 04/14/2013 06:12 PM, Milan Broz wrote: > When user requests encryption (or decryption) of block which > is not aligned to cipher block size through userspace crypto > interface, an OOps like this can happen
And this is a reproducer for the problem above... Milan /* * Check for unaligned buffer to block cipher size in kernel crypto API * fixed by patch: http://article.gmane.org/gmane.linux.kernel.cryptoapi/7980 * * Compile with gcc test.c -o tst */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <inttypes.h> #include <errno.h> #include <unistd.h> #include <sys/socket.h> #include <linux/if_alg.h> #ifndef AF_ALG #define AF_ALG 38 #endif #ifndef SOL_ALG #define SOL_ALG 279 #endif static int kernel_crypt(int opfd, const char *in, char *out, size_t length, const char *iv, size_t iv_length, uint32_t direction) { int r = 0; ssize_t len; struct af_alg_iv *alg_iv; struct cmsghdr *header; uint32_t *type; struct iovec iov = { .iov_base = (void*)(uintptr_t)in, .iov_len = length, }; int iv_msg_size = iv ? CMSG_SPACE(sizeof(*alg_iv) + iv_length) : 0; char buffer[CMSG_SPACE(sizeof(type)) + iv_msg_size]; struct msghdr msg = { .msg_control = buffer, .msg_controllen = sizeof(buffer), .msg_iov = &iov, .msg_iovlen = 1, }; if (!in || !out || !length) return -EINVAL; if ((!iv && iv_length) || (iv && !iv_length)) return -EINVAL; memset(buffer, 0, sizeof(buffer)); /* Set encrypt/decrypt operation */ header = CMSG_FIRSTHDR(&msg); header->cmsg_level = SOL_ALG; header->cmsg_type = ALG_SET_OP; header->cmsg_len = CMSG_LEN(sizeof(type)); type = (void*)CMSG_DATA(header); *type = direction; /* Set IV */ if (iv) { header = CMSG_NXTHDR(&msg, header); header->cmsg_level = SOL_ALG; header->cmsg_type = ALG_SET_IV; header->cmsg_len = iv_msg_size; alg_iv = (void*)CMSG_DATA(header); alg_iv->ivlen = iv_length; memcpy(alg_iv->iv, iv, iv_length); } len = sendmsg(opfd, &msg, 0); if (len != (ssize_t)length) { r = -EIO; goto bad; } len = read(opfd, out, length); if (len != (ssize_t)length) r = -EIO; bad: memset(buffer, 0, sizeof(buffer)); return r; } int main (int argc, char *argv[]) { const char key[32] = "0123456789abcdef0123456789abcdef"; const char iv[16] = "0000000000000001"; struct sockaddr_alg sa = { .salg_family = AF_ALG, .salg_type = "skcipher", .salg_name = "cbc(aes)" }; int tfmfd, opfd; char *data; if (posix_memalign((void*)&data, 4096, 32)) { printf("Cannot alloc memory.\n"); return 1; } tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0); if (tfmfd == -1) goto bad; if (bind(tfmfd, (struct sockaddr *)&sa, sizeof(sa)) == -1) goto bad; opfd = accept(tfmfd, NULL, 0); if (opfd == -1) goto bad; if (setsockopt(tfmfd, SOL_ALG, ALG_SET_KEY, key, sizeof(key)) == -1) goto bad; if (kernel_crypt(opfd, data, data, 1, iv, sizeof(iv), ALG_OP_ENCRYPT) < 0) printf("Cannot encrypt data.\n"); close(tfmfd); close(opfd); free(data); return 0; bad: printf("Cannot initialise cipher.\n"); return 1; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
