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/*
20140117
20241208 - reformated using clang-format
Jan Mojzis
Public domain.
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "load.h"
#include "log.h"
#include "open.h"
#include "writeall.h"
#include "purge.h"
#include "global.h"
#include "bug.h"
#include "e.h"
#include "purge.h"
#include "readall.h"
#include "blocking.h"
#include "sshcrypto.h"
#include "subprocess.h"
/*
The 'subprocess_sign' function reads secret-key from 'keydir' and signs the data
'x' of length 'xlen' and returns it in 'y'. Caller is expecting 'y' of length
'ylen'. Signing is done in a different process, so secret-key is in a separate
memory space than rest of the program.
*/
int subprocess_sign(unsigned char *y, long long ylen, const char *keydir,
unsigned char *x, long long xlen) {
pid_t pid;
int status, fromchild[2] = {-1, -1};
if (ylen != sshcrypto_sign_bytes) bug_inval();
if (xlen != sshcrypto_hash_bytes) bug_inval();
if (!y || !keydir || !x) bug_inval();
if (open_pipe(fromchild) == -1) return -1;
pid = fork();
if (pid == -1) {
close(fromchild[0]);
close(fromchild[1]);
return -1;
}
if (pid == 0) {
unsigned char sk[sshcrypto_sign_SECRETKEYMAX];
unsigned char sm[sshcrypto_sign_MAX + sshcrypto_hash_MAX];
unsigned long long smlen;
close(fromchild[0]);
/* signing starts here */
if (chdir(keydir) == -1) {
log_w2("sign: unable to change directory to ", keydir);
global_die(111);
}
if (load(sshcrypto_sign_secretkeyfilename, sk,
sshcrypto_sign_secretkeybytes) == -1) {
log_w4("sign: unable to load secret-key from file ", keydir, "/",
sshcrypto_sign_secretkeyfilename);
purge(sk, sizeof sk);
global_die(111);
}
if (sshcrypto_sign(sm, &smlen, x, sshcrypto_hash_bytes, sk) != 0) {
log_w4("sign: unable to sign using secret-key from file ", keydir,
"/", sshcrypto_sign_secretkeyfilename);
purge(sk, sizeof sk);
global_die(111);
}
purge(sk, sizeof sk);
if (writeall(fromchild[1], sm, sshcrypto_sign_bytes) == -1) {
log_w1("sign: unable to write signature to parrent process");
global_die(111);
}
close(fromchild[1]);
/* signing ends here */
purge(sm, sizeof sm);
global_die(0);
}
close(fromchild[1]);
blocking_enable(fromchild[0]);
if (readall(fromchild[0], y, ylen) == -1) {
close(fromchild[0]);
return -1;
}
close(fromchild[0]);
while (waitpid(pid, &status, 0) != pid) {}
if (!WIFEXITED(status)) return -1;
return WEXITSTATUS(status);
}
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