ref: d5e45580788cfa62afea322e5676cf9e5f77d0a4
dir: /sys/src/cmd/disk/cryptsetup.c/
// Original Author Taru Karttunen <[email protected]> // This file can be used as both Public Domain or Creative Commons CC0. #include <u.h> #include <libc.h> #include <libsec.h> #include <authsrv.h> typedef struct { uchar Salt[16]; uchar Key[32]; } Slot; typedef struct { uchar Master[32]; Slot Slots[8]; AESstate C1, C2; } XtsState; uchar zeros[16] = {0}; uchar buf[64*1024]; AESstate cbc; XtsState s; void setupkey(char *pass, uchar salt[16], AESstate *aes) { uchar tkey[32]; pbkdf2_x((uchar*)pass, strlen(pass), salt, 16, 9999, tkey, 32, hmac_sha1, SHA1dlen); setupAESstate(aes, tkey, 16, zeros); memset(tkey, 0, sizeof(tkey)); } void freepass(char *pass) { if(pass != nil){ memset(pass, 0, strlen(pass)); free(pass); } } void cformat(char *files[]) { char *pass, *tmp; int fd, i, j; pass = nil; do { freepass(pass); pass = readcons("Password", nil, 1); if(pass == nil || pass[0] == 0) sysfatal("input aborted"); tmp = readcons("Confirm", nil, 1); if(tmp == nil || tmp[0] == 0) sysfatal("input aborted"); i = strcmp(pass, tmp); freepass(tmp); } while(i != 0); for(;*files != nil; files++) { genrandom((uchar*)&s, sizeof(s)); setupkey(pass, s.Slots[0].Salt, &cbc); memcpy(s.Slots[0].Key, s.Master, 32); aesCBCencrypt(s.Slots[0].Key, 32, &cbc); genrandom(buf, 16*4096); for(i=0; i<16; i++) for(j=0; j<8; j++) { buf[(4096*i)+(4*j)+1] = s.Slots[j].Salt[i]; buf[(4096*i)+(4*j)+2] = s.Slots[j].Key[i]; buf[(4096*i)+(4*j)+3] = s.Slots[j].Key[i+16]; } if((fd = open(*files, OWRITE)) < 0) sysfatal("open disk: %r"); /* make the pad for checking crypto */ for(i=0; i<8; i++) buf[(64*1024)-8+i] = ~buf[(64*1024)-16+i]; setupAESstate(&cbc, s.Master, 16, zeros); aes_encrypt(cbc.ekey, cbc.rounds, &buf[(64*1024)-16], &buf[(64*1024)-16]); if(write(fd, buf, 64*1024) != 64*1024) sysfatal("writing disk: %r"); } } void copen(char *files[], int ctl) { char *pass, *name; uchar cbuf[16]; int fd, i, j; pass = nil; for(;*files != nil; files++) { memset(&s, 0, sizeof(s)); if((fd = open(*files, OREAD)) < 0) sysfatal("open disk: %r"); if(read(fd, buf, 1024*64) != 1024*64) sysfatal("read disk: %r"); retrypass: for(i=0; i<16; i++) for(j=0; j<8; j++) { s.Slots[j].Salt[i] = buf[(4096*i)+(4*j)+1]; s.Slots[j].Key[i] = buf[(4096*i)+(4*j)+2]; s.Slots[j].Key[i+16] = buf[(4096*i)+(4*j)+3]; } if(pass == nil){ pass = readcons("Password", nil, 1); if(pass == nil || pass[0] == 0) sysfatal("input aborted"); } setupkey(pass, s.Slots[0].Salt, &cbc); memcpy(s.Master, s.Slots[0].Key, 32); aesCBCdecrypt(s.Master, 32, &cbc); setupAESstate(&cbc, s.Master, 16, zeros); memcpy(cbuf, &buf[(64*1024)-16], 16); aes_decrypt(cbc.dkey, cbc.rounds, cbuf, cbuf); /* make the pad for checking crypto */ for(i=0; i<8; i++) if((cbuf[i] ^ cbuf[i+8]) != 255) { freepass(pass); pass = nil; fprint(2, "wrong key\n"); goto retrypass; } fd2path(fd, (char*)buf, sizeof(buf)); close(fd); if((name = strrchr(*files, '/')) != nil) name++; else name = *files; if(fprint(ctl, "crypt %q %q %.32H\n", name, (char*)buf, s.Master) < 0) sysfatal("write: %r"); } } void usage(void) { print("usage:\n" "%s -f files\t\t# Format file or device\n" "%s -o files\t\t# Print commandline for open\n" "%s -i files\t\t# Install (open) files\n", argv0, argv0, argv0); exits("usage"); } void main(int argc, char *argv[]) { enum { NoMode, Format, Open, Install, }; int mode, ctl; quotefmtinstall(); fmtinstall('H', encodefmt); ctl = 1; mode = NoMode; ARGBEGIN { default: usage(); case 'f': mode = Format; break; case 'o': mode = Open; break; case 'i': mode = Install; break; } ARGEND; if(argc < 0) usage(); switch(mode){ default: usage(); case Format: cformat(argv); break; case Install: if((ctl = open("/dev/fs/ctl", OWRITE)) < 0) sysfatal("open ctl: %r"); /* no break */ case Open: copen(argv, ctl); break; } exits(nil); }