diff options
author | Micah Anderson <micah@riseup.net> | 2008-06-18 23:35:20 -0400 |
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committer | Micah Anderson <micah@riseup.net> | 2008-06-18 23:35:20 -0400 |
commit | 308aa104f66a40f2426c13b96f48631937502f6b (patch) | |
tree | 55e1b1427ba23750b0c239e5d43fc3ffa49b0293 /src/keytrans/gnutls-helpers.c | |
parent | a9a56853a27e1dbce3c48af327b0adff0e4c38e0 (diff) | |
parent | 9c94e937fbe8beb56956365cac07d6eff45215cd (diff) |
Merge commit 'dkg/master'
Conflicts:
doc/MonkeySpec
Diffstat (limited to 'src/keytrans/gnutls-helpers.c')
-rw-r--r-- | src/keytrans/gnutls-helpers.c | 446 |
1 files changed, 446 insertions, 0 deletions
diff --git a/src/keytrans/gnutls-helpers.c b/src/keytrans/gnutls-helpers.c new file mode 100644 index 0000000..5b4c46a --- /dev/null +++ b/src/keytrans/gnutls-helpers.c @@ -0,0 +1,446 @@ +/* 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> + +/* for exit() */ +#include <unistd.h> + +#include <assert.h> + +/* higher levels allow more frivolous error messages through. + this is set with the MONKEYSPHERE_DEBUG variable */ +static int loglevel = 0; + +void err(int level, const char* fmt, ...) { + va_list ap; + if (level > loglevel) + return; + 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) +{ + assert(sizeof(out) >= 2*sizeof(keyid)); + hex_print_data((char*)out, (const char*)keyid, sizeof(keyid)); +} + +/* you must have twice as many bytes in the out buffer as in the in buffer */ +void hex_print_data(char* out, const char* in, size_t incount) +{ + static const char hex[16] = "0123456789ABCDEF"; + unsigned int inix = 0, outix = 0; + + while (inix < incount) { + out[outix] = hex[(in[inix] >> 4) & 0x0f]; + out[outix + 1] = hex[in[inix] & 0x0f]; + inix++; + outix += 2; + } +} + +unsigned char hex2bin(unsigned char x) { + if ((x >= '0') && (x <= '9')) + return x - '0'; + if ((x >= 'A') && (x <= 'F')) + return 10 + x - 'A'; + if ((x >= 'a') && (x <= 'f')) + return 10 + x - 'a'; + return 0xff; +} + +void collapse_printable_keyid(gnutls_openpgp_keyid_t out, printable_keyid in) { + unsigned int pkix = 0, outkix = 0; + + while (pkix < sizeof(printable_keyid)) { + unsigned hi = hex2bin(in[pkix]); + unsigned lo = hex2bin(in[pkix + 1]); + if (hi == 0xff) { + err(0, "character '%c' is not a hex char\n", in[pkix]); + exit(1); + } + if (lo == 0xff) { + err(0, "character '%c' is not a hex char\n", in[pkix + 1]); + exit(1); + } + out[outkix] = lo | (hi << 4); + + pkix += 2; + outkix++; + } +} + +int convert_string_to_keyid(gnutls_openpgp_keyid_t out, const char* str) { + printable_keyid p; + int ret; + + ret = convert_string_to_printable_keyid(p, str); + if (ret == 0) + collapse_printable_keyid(out, p); + return ret; +} +int convert_string_to_printable_keyid(printable_keyid pkeyid, const char* str) { + int arglen, x; + arglen = 0; + x = 0; + while ((arglen <= sizeof(printable_keyid)) && + (str[x] != '\0')) { + if (isxdigit(str[x])) { + if (arglen == sizeof(printable_keyid)) { + err(0, "There are more than %d hex digits in the keyid '%s'\n", sizeof(printable_keyid), str); + return 1; + } + pkeyid[arglen] = str[x]; + arglen++; + } + x++; + } + + if (arglen != sizeof(printable_keyid)) { + err(0, "Keyid '%s' is not %d hex digits in length\n", str, sizeof(printable_keyid)); + return 1; + } + return 0; +} + + + +int init_gnutls() { + const char* version = NULL; + const char* debug_string = NULL; + int ret; + + if (debug_string = getenv("MONKEYSPHERE_DEBUG"), debug_string) { + loglevel = atoi(debug_string); + } + + if (ret = gnutls_global_init(), ret) { + err(0, "Failed to do gnutls_global_init() (error: %d)\n", ret); + return 1; + } + + version = gnutls_check_version(NULL); + + if (version) + err(1, "gnutls version: %s\n", version); + else { + err(0, "no gnutls version found!\n"); + return 1; + } + + gnutls_global_set_log_function(logfunc); + + gnutls_global_set_log_level(loglevel); + err(1, "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(0,"a is larger\n"); + return 1; + } + if (a->size < b->size) { + err(0,"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(0,"out of memory!\n"); + return -1; + } + d->size = bufsize; + } else { + bufsize = d->size; + } + f = fdopen(fd, "r"); + if (NULL == f) { + err(0,"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(0,"out of memory!\n"); + return -1; + }; + d->size = bufsize; + } + len += fread(d->data + len, 1, bufsize - len, f); + /* err(0,"read %d bytes\n", len); */ + } + if (ferror(f)) { + err(0,"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(0,"failed to stat '%s'\n", fname); + return -1; + } + + c = gnutls_realloc(d->data, sbuf.st_size); + if (NULL == c) { + err(0,"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(0,"failed to open '%s' for reading\n", fname); + return -1; + } + + x = fread(d->data, d->size, 1, file); + if (x != 1) { + err(0,"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(0,"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(0,"failed to write size of datum.\n"); + return -2; + } + if (looks_negative) { + if (write(fd, &zero, 1) != 1) { + err(0,"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(0,"bad pointer passed to create_writing_pipe()\n"); + return -1; + } + + if (ret = pipe(p), ret == -1) { + err(0,"failed to create a pipe (error: %d \"%s\")\n", errno, strerror(errno)); + return -1; + } + + *pid = fork(); + if (*pid == -1) { + err(0,"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(0,"Failed to transfer reading file descriptor to stdin (error: %d \"%s\")\n", errno, strerror(errno)); + exit(1); + } + execv(path, argv); + err(0,"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(0,"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(0,"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(0,"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(0,"invalid character in domain name: %c\n", *userid); + goto fail; + } + } + /* ensure that the last character is valid: */ + if (!isalnum(*(userid - 1))) { + err(0,"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; +} |