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-rw-r--r--src/gpg2ssh/gnutls-helpers.c364
1 files changed, 364 insertions, 0 deletions
diff --git a/src/gpg2ssh/gnutls-helpers.c b/src/gpg2ssh/gnutls-helpers.c
new file mode 100644
index 0000000..6eae29e
--- /dev/null
+++ b/src/gpg2ssh/gnutls-helpers.c
@@ -0,0 +1,364 @@
+/* Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net> */
+/* Date: Fri, 04 Apr 2008 19:31:16 -0400 */
+/* License: GPL v3 or later */
+
+#include "gnutls-helpers.h"
+/* for htonl() */
+#include <arpa/inet.h>
+
+/* for setlocale() */
+#include <locale.h>
+
+/* for isalnum() */
+#include <ctype.h>
+
+int loglevel = 0;
+
+
+void err(const char* fmt, ...) {
+ va_list ap;
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ fflush(stderr);
+}
+
+void logfunc(int level, const char* string) {
+ fprintf(stderr, "GnuTLS Logging (%d): %s\n", level, string);
+}
+
+void init_keyid(gnutls_openpgp_keyid_t keyid) {
+ memset(keyid, 'x', sizeof(gnutls_openpgp_keyid_t));
+}
+
+
+
+void make_keyid_printable(printable_keyid out, gnutls_openpgp_keyid_t keyid)
+{
+ static const char hex[16] = "0123456789ABCDEF";
+ unsigned int kix = 0, outix = 0;
+
+ while (kix < sizeof(gnutls_openpgp_keyid_t)) {
+ out[outix] = hex[(keyid[kix] >> 4) & 0x0f];
+ out[outix + 1] = hex[keyid[kix] & 0x0f];
+ kix++;
+ outix += 2;
+ }
+}
+
+
+int init_gnutls() {
+ const char* version = NULL;
+ const char* debug_string = NULL;
+ int ret;
+
+ if (ret = gnutls_global_init(), ret) {
+ err("Failed to do gnutls_global_init() (error: %d)\n", ret);
+ return 1;
+ }
+
+ version = gnutls_check_version(NULL);
+
+ if (version)
+ err("gnutls version: %s\n", version);
+ else {
+ err("no version found!\n");
+ return 1;
+ }
+
+ if (debug_string = getenv("MONKEYSPHERE_DEBUG"), debug_string) {
+ loglevel = atoi(debug_string);
+ gnutls_global_set_log_function(logfunc);
+
+ gnutls_global_set_log_level(loglevel);
+ err("set log level to %d\n", loglevel);
+ }
+ return 0;
+}
+
+void init_datum(gnutls_datum_t* d) {
+ d->data = NULL;
+ d->size = 0;
+}
+void copy_datum(gnutls_datum_t* dest, const gnutls_datum_t* src) {
+ dest->data = gnutls_realloc(dest->data, src->size);
+ dest->size = src->size;
+ memcpy(dest->data, src->data, src->size);
+}
+int compare_data(const gnutls_datum_t* a, const gnutls_datum_t* b) {
+ if (a->size > b->size) {
+ err("a is larger\n");
+ return 1;
+ }
+ if (a->size < b->size) {
+ err("b is larger\n");
+ return -1;
+ }
+ return memcmp(a->data, b->data, a->size);
+}
+void free_datum(gnutls_datum_t* d) {
+ gnutls_free(d->data);
+ d->data = NULL;
+ d->size = 0;
+}
+
+/* read the passed-in string, store in a single datum */
+int set_datum_string(gnutls_datum_t* d, const char* s) {
+ unsigned int x = strlen(s)+1;
+ unsigned char* c = NULL;
+
+ c = gnutls_realloc(d->data, x);
+ if (NULL == c)
+ return -1;
+ d->data = c;
+ d->size = x;
+ memcpy(d->data, s, x);
+ return 0;
+}
+
+/* read the passed-in file descriptor until EOF, store in a single
+ datum */
+int set_datum_fd(gnutls_datum_t* d, int fd) {
+ unsigned int bufsize = 1024;
+ unsigned int len = 0;
+
+ FILE* f = fdopen(fd, "r");
+ if (bufsize > d->size) {
+ bufsize = 1024;
+ d->data = gnutls_realloc(d->data, bufsize);
+ if (d->data == NULL) {
+ err("out of memory!\n");
+ return -1;
+ }
+ d->size = bufsize;
+ } else {
+ bufsize = d->size;
+ }
+ f = fdopen(fd, "r");
+ if (NULL == f) {
+ err("could not fdopen FD %d\n", fd);
+ }
+ clearerr(f);
+ while (!feof(f) && !ferror(f)) {
+ if (len == bufsize) {
+ /* allocate more space by doubling: */
+ bufsize *= 2;
+ d->data = gnutls_realloc(d->data, bufsize);
+ if (d->data == NULL) {
+ err("out of memory!\n");
+ return -1;
+ };
+ d->size = bufsize;
+ }
+ len += fread(d->data + len, 1, bufsize - len, f);
+ /* err("read %d bytes\n", len); */
+ }
+ if (ferror(f)) {
+ err("Error reading from fd %d (error: %d) (error: %d '%s')\n", fd, ferror(f), errno, strerror(errno));
+ return -1;
+ }
+
+ /* touch up buffer size to match reality: */
+ d->data = gnutls_realloc(d->data, len);
+ d->size = len;
+ return 0;
+}
+
+/* read the file indicated (by name) in the fname parameter. store
+ its entire contents in a single datum. */
+int set_datum_file(gnutls_datum_t* d, const char* fname) {
+ struct stat sbuf;
+ unsigned char* c = NULL;
+ FILE* file = NULL;
+ size_t x = 0;
+
+ if (0 != stat(fname, &sbuf)) {
+ err("failed to stat '%s'\n", fname);
+ return -1;
+ }
+
+ c = gnutls_realloc(d->data, sbuf.st_size);
+ if (NULL == c) {
+ err("failed to allocate %d bytes for '%s'\n", sbuf.st_size, fname);
+ return -1;
+ }
+
+ d->data = c;
+ d->size = sbuf.st_size;
+ file = fopen(fname, "r");
+ if (NULL == file) {
+ err("failed to open '%s' for reading\n", fname);
+ return -1;
+ }
+
+ x = fread(d->data, d->size, 1, file);
+ if (x != 1) {
+ err("tried to read %d bytes, read %d instead from '%s'\n", d->size, x, fname);
+ fclose(file);
+ return -1;
+ }
+ fclose(file);
+ return 0;
+}
+
+int write_datum_fd(int fd, const gnutls_datum_t* d) {
+ if (d->size != write(fd, d->data, d->size)) {
+ err("failed to write body of datum.\n");
+ return -1;
+ }
+ return 0;
+}
+
+
+int write_datum_fd_with_length(int fd, const gnutls_datum_t* d) {
+ uint32_t len;
+ int looks_negative = (d->data[0] & 0x80);
+ unsigned char zero = 0;
+
+ /* if the first bit is 1, then the datum will appear negative in the
+ MPI encoding style used by OpenSSH. In that case, we'll increase
+ the length by one, and dump out one more byte */
+
+ if (looks_negative) {
+ len = htonl(d->size + 1);
+ } else {
+ len = htonl(d->size);
+ }
+ if (write(fd, &len, sizeof(len)) != sizeof(len)) {
+ err("failed to write size of datum.\n");
+ return -2;
+ }
+ if (looks_negative) {
+ if (write(fd, &zero, 1) != 1) {
+ err("failed to write padding byte for MPI.\n");
+ return -2;
+ }
+ }
+ return write_datum_fd(fd, d);
+}
+
+int write_data_fd_with_length(int fd, const gnutls_datum_t** d, unsigned int num) {
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < num; i++)
+ if (ret = write_datum_fd_with_length(fd, d[i]), ret != 0)
+ return ret;
+
+ return 0;
+}
+
+
+int datum_from_string(gnutls_datum_t* d, const char* str) {
+ d->size = strlen(str);
+ d->data = gnutls_realloc(d->data, d->size);
+ if (d->data == 0)
+ return ENOMEM;
+ memcpy(d->data, str, d->size);
+ return 0;
+}
+
+
+int create_writing_pipe(pid_t* pid, const char* path, char* const argv[]) {
+ int p[2];
+ int ret;
+
+ if (pid == NULL) {
+ err("bad pointer passed to create_writing_pipe()\n");
+ return -1;
+ }
+
+ if (ret = pipe(p), ret == -1) {
+ err("failed to create a pipe (error: %d \"%s\")\n", errno, strerror(errno));
+ return -1;
+ }
+
+ *pid = fork();
+ if (*pid == -1) {
+ err("Failed to fork (error: %d \"%s\")\n", errno, strerror(errno));
+ return -1;
+ }
+ if (*pid == 0) { /* this is the child */
+ close(p[1]); /* close unused write end */
+
+ if (0 != dup2(p[0], 0)) { /* map the reading end into stdin */
+ err("Failed to transfer reading file descriptor to stdin (error: %d \"%s\")\n", errno, strerror(errno));
+ exit(1);
+ }
+ execv(path, argv);
+ err("exec %s failed (error: %d \"%s\")\n", path, errno, strerror(errno));
+ /* close the open file descriptors */
+ close(p[0]);
+ close(0);
+
+ exit(1);
+ } else { /* this is the parent */
+ close(p[0]); /* close unused read end */
+ return p[1];
+ }
+}
+
+int validate_ssh_host_userid(const char* userid) {
+ char* oldlocale = setlocale(LC_ALL, "C");
+
+ /* choke if userid does not match the expected format
+ ("ssh://fully.qualified.domain.name") */
+ if (strncmp("ssh://", userid, strlen("ssh://")) != 0) {
+ err("The user ID should start with ssh:// for a host key\n");
+ goto fail;
+ }
+ /* so that isalnum will work properly */
+ userid += strlen("ssh://");
+ while (0 != (*userid)) {
+ if (!isalnum(*userid)) {
+ err("label did not start with a letter or a digit! (%s)\n", userid);
+ goto fail;
+ }
+ userid++;
+ while (isalnum(*userid) || ('-' == (*userid)))
+ userid++;
+ if (('.' == (*userid)) || (0 == (*userid))) { /* clean end of label:
+ check last char
+ isalnum */
+ if (!isalnum(*(userid - 1))) {
+ err("label did not end with a letter or a digit!\n");
+ goto fail;
+ }
+ if ('.' == (*userid)) /* advance to the start of the next label */
+ userid++;
+ } else {
+ err("invalid character in domain name: %c\n", *userid);
+ goto fail;
+ }
+ }
+ /* ensure that the last character is valid: */
+ if (!isalnum(*(userid - 1))) {
+ err("hostname did not end with a letter or a digit!\n");
+ goto fail;
+ }
+ /* FIXME: fqdn's can be unicode now, thanks to RFC 3490 -- how do we
+ make sure that we've got an OK string? */
+
+ return 0;
+
+ fail:
+ setlocale(LC_ALL, oldlocale);
+ return 1;
+}
+
+/* http://tools.ietf.org/html/rfc4880#section-5.5.2 */
+size_t get_openpgp_mpi_size(gnutls_datum_t* d) {
+ return 2 + d->size;
+}
+
+int write_openpgp_mpi_to_fd(int fd, gnutls_datum_t* d) {
+ uint16_t x;
+
+ x = d->size * 8;
+ x = htons(x);
+
+ write(fd, &x, sizeof(x));
+ write(fd, d->data, d->size);
+
+ return 0;
+}
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