return c;
}
+/*
+ * Find a character in a string, unless it's a colon contained within
+ * square brackets. Used for untangling strings of the form
+ * 'host:port', where host can be an IPv6 literal.
+ *
+ * We provide several variants of this function, with semantics like
+ * various standard string.h functions.
+ */
+static const char *host_strchr_internal(const char *s, const char *set,
+ int first)
+{
+ int brackets = 0;
+ const char *ret = NULL;
+
+ while (1) {
+ if (!*s)
+ return ret;
+
+ if (*s == '[')
+ brackets++;
+ else if (*s == ']' && brackets > 0)
+ brackets--;
+ else if (brackets && *s == ':')
+ /* never match */ ;
+ else if (strchr(set, *s)) {
+ ret = s;
+ if (first)
+ return ret;
+ }
+
+ s++;
+ }
+}
+size_t host_strcspn(const char *s, const char *set)
+{
+ const char *answer = host_strchr_internal(s, set, TRUE);
+ if (answer)
+ return answer - s;
+ else
+ return strlen(s);
+}
+char *host_strchr(const char *s, int c)
+{
+ char set[2];
+ set[0] = c;
+ set[1] = '\0';
+ return (char *) host_strchr_internal(s, set, TRUE);
+}
+char *host_strrchr(const char *s, int c)
+{
+ char set[2];
+ set[0] = c;
+ set[1] = '\0';
+ return (char *) host_strchr_internal(s, set, FALSE);
+}
+
+#ifdef TEST_HOST_STRFOO
+int main(void)
+{
+ int passes = 0, fails = 0;
+
+#define TEST1(func, string, arg2, suffix, result) do \
+ { \
+ const char *str = string; \
+ unsigned ret = func(string, arg2) suffix; \
+ if (ret == result) { \
+ passes++; \
+ } else { \
+ printf("fail: %s(%s,%s)%s = %u, expected %u\n", \
+ #func, #string, #arg2, #suffix, ret, result); \
+ fails++; \
+ } \
+} while (0)
+
+ TEST1(host_strchr, "[1:2:3]:4:5", ':', -str, 7);
+ TEST1(host_strrchr, "[1:2:3]:4:5", ':', -str, 9);
+ TEST1(host_strcspn, "[1:2:3]:4:5", "/:",, 7);
+ TEST1(host_strchr, "[1:2:3]", ':', == NULL, 1);
+ TEST1(host_strrchr, "[1:2:3]", ':', == NULL, 1);
+ TEST1(host_strcspn, "[1:2:3]", "/:",, 7);
+ TEST1(host_strcspn, "[1:2/3]", "/:",, 4);
+ TEST1(host_strcspn, "[1:2:3]/", "/:",, 7);
+
+ printf("passed %d failed %d total %d\n", passes, fails, passes+fails);
+ return fails != 0 ? 1 : 0;
+}
+/* Stubs to stop the rest of this module causing compile failures. */
+void modalfatalbox(char *fmt, ...) {}
+int conf_get_int(Conf *conf, int primary) { return 0; }
+char *conf_get_str(Conf *conf, int primary) { return NULL; }
+#endif /* TEST_HOST_STRFOO */
+
+/*
+ * Trim square brackets off the outside of an IPv6 address literal.
+ * Leave all other strings unchanged. Returns a fresh dynamically
+ * allocated string.
+ */
+char *host_strduptrim(const char *s)
+{
+ if (s[0] == '[') {
+ const char *p = s+1;
+ int colons = 0;
+ while (*p && *p != ']') {
+ if (isxdigit((unsigned char)*p))
+ /* OK */;
+ else if (*p == ':')
+ colons++;
+ else
+ break;
+ p++;
+ }
+ if (*p == ']' && !p[1] && colons > 1) {
+ /*
+ * This looks like an IPv6 address literal (hex digits and
+ * at least two colons, contained in square brackets).
+ * Trim off the brackets.
+ */
+ return dupprintf("%.*s", (int)(p - (s+1)), s+1);
+ }
+ }
+
+ /*
+ * Any other shape of string is simply duplicated.
+ */
+ return dupstr(s);
+}
+
prompts_t *new_prompts(void *frontend)
{
prompts_t *p = snew(prompts_t);
p->name_reqd = p->instr_reqd = FALSE;
return p;
}
-void add_prompt(prompts_t *p, char *promptstr, int echo, size_t len)
+void add_prompt(prompts_t *p, char *promptstr, int echo)
{
prompt_t *pr = snew(prompt_t);
- char *result = snewn(len, char);
pr->prompt = promptstr;
pr->echo = echo;
- pr->result = result;
- pr->result_len = len;
+ pr->result = NULL;
+ pr->resultsize = 0;
p->n_prompts++;
p->prompts = sresize(p->prompts, p->n_prompts, prompt_t *);
p->prompts[p->n_prompts-1] = pr;
}
+void prompt_ensure_result_size(prompt_t *pr, int newlen)
+{
+ if ((int)pr->resultsize < newlen) {
+ char *newbuf;
+ newlen = newlen * 5 / 4 + 512; /* avoid too many small allocs */
+
+ /*
+ * We don't use sresize / realloc here, because we will be
+ * storing sensitive stuff like passwords in here, and we want
+ * to make sure that the data doesn't get copied around in
+ * memory without the old copy being destroyed.
+ */
+ newbuf = snewn(newlen, char);
+ memcpy(newbuf, pr->result, pr->resultsize);
+ smemclr(pr->result, pr->resultsize);
+ sfree(pr->result);
+ pr->result = newbuf;
+ pr->resultsize = newlen;
+ }
+}
+void prompt_set_result(prompt_t *pr, const char *newstr)
+{
+ prompt_ensure_result_size(pr, strlen(newstr) + 1);
+ strcpy(pr->result, newstr);
+}
void free_prompts(prompts_t *p)
{
size_t i;
for (i=0; i < p->n_prompts; i++) {
prompt_t *pr = p->prompts[i];
- memset(pr->result, 0, pr->result_len); /* burn the evidence */
+ smemclr(pr->result, pr->resultsize); /* burn the evidence */
sfree(pr->result);
sfree(pr->prompt);
sfree(pr);
return p;
}
+void burnstr(char *string) /* sfree(str), only clear it first */
+{
+ if (string) {
+ smemclr(string, strlen(string));
+ sfree(string);
+ }
+}
+
+int toint(unsigned u)
+{
+ /*
+ * Convert an unsigned to an int, without running into the
+ * undefined behaviour which happens by the strict C standard if
+ * the value overflows. You'd hope that sensible compilers would
+ * do the sensible thing in response to a cast, but actually I
+ * don't trust modern compilers not to do silly things like
+ * assuming that _obviously_ you wouldn't have caused an overflow
+ * and so they can elide an 'if (i < 0)' test immediately after
+ * the cast.
+ *
+ * Sensible compilers ought of course to optimise this entire
+ * function into 'just return the input value'!
+ */
+ if (u <= (unsigned)INT_MAX)
+ return (int)u;
+ else if (u >= (unsigned)INT_MIN) /* wrap in cast _to_ unsigned is OK */
+ return INT_MIN + (int)(u - (unsigned)INT_MIN);
+ else
+ return INT_MIN; /* fallback; should never occur on binary machines */
+}
+
/*
* Do an sprintf(), but into a custom-allocated buffer.
*
}
/* ----------------------------------------------------------------------
- * Base64 encoding routine. This is required in public-key writing
- * but also in HTTP proxy handling, so it's centralised here.
+ * Core base64 encoding and decoding routines.
*/
void base64_encode_atom(unsigned char *data, int n, char *out)
out[3] = '=';
}
+int base64_decode_atom(char *atom, unsigned char *out)
+{
+ int vals[4];
+ int i, v, len;
+ unsigned word;
+ char c;
+
+ for (i = 0; i < 4; i++) {
+ c = atom[i];
+ if (c >= 'A' && c <= 'Z')
+ v = c - 'A';
+ else if (c >= 'a' && c <= 'z')
+ v = c - 'a' + 26;
+ else if (c >= '0' && c <= '9')
+ v = c - '0' + 52;
+ else if (c == '+')
+ v = 62;
+ else if (c == '/')
+ v = 63;
+ else if (c == '=')
+ v = -1;
+ else
+ return 0; /* invalid atom */
+ vals[i] = v;
+ }
+
+ if (vals[0] == -1 || vals[1] == -1)
+ return 0;
+ if (vals[2] == -1 && vals[3] != -1)
+ return 0;
+
+ if (vals[3] != -1)
+ len = 3;
+ else if (vals[2] != -1)
+ len = 2;
+ else
+ len = 1;
+
+ word = ((vals[0] << 18) |
+ (vals[1] << 12) | ((vals[2] & 0x3F) << 6) | (vals[3] & 0x3F));
+ out[0] = (word >> 16) & 0xFF;
+ if (len > 1)
+ out[1] = (word >> 8) & 0xFF;
+ if (len > 2)
+ out[2] = word & 0xFF;
+ return len;
+}
+
/* ----------------------------------------------------------------------
* Generic routines to deal with send buffers: a linked list of
* smallish blocks, with the operations
* - return the current size of the buffer chain in bytes
*/
-#define BUFFER_GRANULE 512
+#define BUFFER_MIN_GRANULE 512
struct bufchain_granule {
struct bufchain_granule *next;
- int buflen, bufpos;
- char buf[BUFFER_GRANULE];
+ char *bufpos, *bufend, *bufmax;
};
void bufchain_init(bufchain *ch)
ch->buffersize += len;
- if (ch->tail && ch->tail->buflen < BUFFER_GRANULE) {
- int copylen = min(len, BUFFER_GRANULE - ch->tail->buflen);
- memcpy(ch->tail->buf + ch->tail->buflen, buf, copylen);
- buf += copylen;
- len -= copylen;
- ch->tail->buflen += copylen;
- }
while (len > 0) {
- int grainlen = min(len, BUFFER_GRANULE);
- struct bufchain_granule *newbuf;
- newbuf = snew(struct bufchain_granule);
- newbuf->bufpos = 0;
- newbuf->buflen = grainlen;
- memcpy(newbuf->buf, buf, grainlen);
- buf += grainlen;
- len -= grainlen;
- if (ch->tail)
- ch->tail->next = newbuf;
- else
- ch->head = ch->tail = newbuf;
- newbuf->next = NULL;
- ch->tail = newbuf;
+ if (ch->tail && ch->tail->bufend < ch->tail->bufmax) {
+ int copylen = min(len, ch->tail->bufmax - ch->tail->bufend);
+ memcpy(ch->tail->bufend, buf, copylen);
+ buf += copylen;
+ len -= copylen;
+ ch->tail->bufend += copylen;
+ }
+ if (len > 0) {
+ int grainlen =
+ max(sizeof(struct bufchain_granule) + len, BUFFER_MIN_GRANULE);
+ struct bufchain_granule *newbuf;
+ newbuf = smalloc(grainlen);
+ newbuf->bufpos = newbuf->bufend =
+ (char *)newbuf + sizeof(struct bufchain_granule);
+ newbuf->bufmax = (char *)newbuf + grainlen;
+ newbuf->next = NULL;
+ if (ch->tail)
+ ch->tail->next = newbuf;
+ else
+ ch->head = newbuf;
+ ch->tail = newbuf;
+ }
}
}
while (len > 0) {
int remlen = len;
assert(ch->head != NULL);
- if (remlen >= ch->head->buflen - ch->head->bufpos) {
- remlen = ch->head->buflen - ch->head->bufpos;
+ if (remlen >= ch->head->bufend - ch->head->bufpos) {
+ remlen = ch->head->bufend - ch->head->bufpos;
tmp = ch->head;
ch->head = tmp->next;
- sfree(tmp);
if (!ch->head)
ch->tail = NULL;
+ sfree(tmp);
} else
ch->head->bufpos += remlen;
ch->buffersize -= remlen;
void bufchain_prefix(bufchain *ch, void **data, int *len)
{
- *len = ch->head->buflen - ch->head->bufpos;
- *data = ch->head->buf + ch->head->bufpos;
+ *len = ch->head->bufend - ch->head->bufpos;
+ *data = ch->head->bufpos;
}
void bufchain_fetch(bufchain *ch, void *data, int len)
int remlen = len;
assert(tmp != NULL);
- if (remlen >= tmp->buflen - tmp->bufpos)
- remlen = tmp->buflen - tmp->bufpos;
- memcpy(data_c, tmp->buf + tmp->bufpos, remlen);
+ if (remlen >= tmp->bufend - tmp->bufpos)
+ remlen = tmp->bufend - tmp->bufpos;
+ memcpy(data_c, tmp->bufpos, remlen);
tmp = tmp->next;
len -= remlen;
else
return conf_get_str(conf, CONF_host);
}
+
+#ifndef PLATFORM_HAS_SMEMCLR
+/*
+ * Securely wipe memory.
+ *
+ * The actual wiping is no different from what memset would do: the
+ * point of 'securely' is to try to be sure over-clever compilers
+ * won't optimise away memsets on variables that are about to be freed
+ * or go out of scope. See
+ * https://buildsecurityin.us-cert.gov/bsi-rules/home/g1/771-BSI.html
+ *
+ * Some platforms (e.g. Windows) may provide their own version of this
+ * function.
+ */
+void smemclr(void *b, size_t n) {
+ volatile char *vp;
+
+ if (b && n > 0) {
+ /*
+ * Zero out the memory.
+ */
+ memset(b, 0, n);
+
+ /*
+ * Perform a volatile access to the object, forcing the
+ * compiler to admit that the previous memset was important.
+ *
+ * This while loop should in practice run for zero iterations
+ * (since we know we just zeroed the object out), but in
+ * theory (as far as the compiler knows) it might range over
+ * the whole object. (If we had just written, say, '*vp =
+ * *vp;', a compiler could in principle have 'helpfully'
+ * optimised the memset into only zeroing out the first byte.
+ * This should be robust.)
+ */
+ vp = b;
+ while (*vp) vp++;
+ }
+}
+#endif
+
+/*
+ * Validate a manual host key specification (either entered in the
+ * GUI, or via -hostkey). If valid, we return TRUE, and update 'key'
+ * to contain a canonicalised version of the key string in 'key'
+ * (which is guaranteed to take up at most as much space as the
+ * original version), suitable for putting into the Conf. If not
+ * valid, we return FALSE.
+ */
+int validate_manual_hostkey(char *key)
+{
+ char *p, *q, *r, *s;
+
+ /*
+ * Step through the string word by word, looking for a word that's
+ * in one of the formats we like.
+ */
+ p = key;
+ while ((p += strspn(p, " \t"))[0]) {
+ q = p;
+ p += strcspn(p, " \t");
+ if (*p) *p++ = '\0';
+
+ /*
+ * Now q is our word.
+ */
+
+ if (strlen(q) == 16*3 - 1 &&
+ q[strspn(q, "0123456789abcdefABCDEF:")] == 0) {
+ /*
+ * Might be a key fingerprint. Check the colons are in the
+ * right places, and if so, return the same fingerprint
+ * canonicalised into lowercase.
+ */
+ int i;
+ for (i = 0; i < 16; i++)
+ if (q[3*i] == ':' || q[3*i+1] == ':')
+ goto not_fingerprint; /* sorry */
+ for (i = 0; i < 15; i++)
+ if (q[3*i+2] != ':')
+ goto not_fingerprint; /* sorry */
+ for (i = 0; i < 16*3 - 1; i++)
+ key[i] = tolower(q[i]);
+ key[16*3 - 1] = '\0';
+ return TRUE;
+ }
+ not_fingerprint:;
+
+ /*
+ * Before we check for a public-key blob, trim newlines out of
+ * the middle of the word, in case someone's managed to paste
+ * in a public-key blob _with_ them.
+ */
+ for (r = s = q; *r; r++)
+ if (*r != '\n' && *r != '\r')
+ *s++ = *r;
+ *s = '\0';
+
+ if (strlen(q) % 4 == 0 && strlen(q) > 2*4 &&
+ q[strspn(q, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz+/=")] == 0) {
+ /*
+ * Might be a base64-encoded SSH-2 public key blob. Check
+ * that it starts with a sensible algorithm string. No
+ * canonicalisation is necessary for this string type.
+ *
+ * The algorithm string must be at most 64 characters long
+ * (RFC 4251 section 6).
+ */
+ unsigned char decoded[6];
+ unsigned alglen;
+ int minlen;
+ int len = 0;
+
+ len += base64_decode_atom(q, decoded+len);
+ if (len < 3)
+ goto not_ssh2_blob; /* sorry */
+ len += base64_decode_atom(q+4, decoded+len);
+ if (len < 4)
+ goto not_ssh2_blob; /* sorry */
+
+ alglen = GET_32BIT_MSB_FIRST(decoded);
+ if (alglen > 64)
+ goto not_ssh2_blob; /* sorry */
+
+ minlen = ((alglen + 4) + 2) / 3;
+ if (strlen(q) < minlen)
+ goto not_ssh2_blob; /* sorry */
+
+ strcpy(key, q);
+ return TRUE;
+ }
+ not_ssh2_blob:;
+ }
+
+ return FALSE;
+}
+
+int smemeq(const void *av, const void *bv, size_t len)
+{
+ const unsigned char *a = (const unsigned char *)av;
+ const unsigned char *b = (const unsigned char *)bv;
+ unsigned val = 0;
+
+ while (len-- > 0) {
+ val |= *a++ ^ *b++;
+ }
+ /* Now val is 0 iff we want to return 1, and in the range
+ * 0x01..0xFF iff we want to return 0. So subtracting from 0x100
+ * will clear bit 8 iff we want to return 0, and leave it set iff
+ * we want to return 1, so then we can just shift down. */
+ return (0x100 - val) >> 8;
+}
projects / PuTTY.git / blobdiff