+/************************************************/
+/* Return offset in ops table, or -1 if not found.
+Repoint to just after the operator in the string.
+
+Argument:
+ ss string representation of operator
+ opname split-out operator name
+*/
+
+static int
+identify_operator(const uschar ** ss, uschar ** opname)
+{
+const uschar * s = *ss;
+uschar name[256];
+
+/* Numeric comparisons are symbolic */
+
+if (*s == '=' || *s == '>' || *s == '<')
+ {
+ int p = 0;
+ name[p++] = *s++;
+ if (*s == '=')
+ {
+ name[p++] = '=';
+ s++;
+ }
+ name[p] = 0;
+ }
+
+/* All other conditions are named */
+
+else
+ s = read_name(name, sizeof(name), s, US"_");
+*ss = s;
+
+/* If we haven't read a name, it means some non-alpha character is first. */
+
+if (!name[0])
+ {
+ expand_string_message = string_sprintf("condition name expected, "
+ "but found \"%.16s\"", s);
+ return -1;
+ }
+if (opname)
+ *opname = string_copy(name);
+
+return chop_match(name, cond_table, nelem(cond_table));
+}
+
+
+/*************************************************
+* Handle MD5 or SHA-1 computation for HMAC *
+*************************************************/
+
+/* These are some wrapping functions that enable the HMAC code to be a bit
+cleaner. A good compiler will spot the tail recursion.
+
+Arguments:
+ type HMAC_MD5 or HMAC_SHA1
+ remaining are as for the cryptographic hash functions
+
+Returns: nothing
+*/
+
+static void
+chash_start(int type, void * base)
+{
+if (type == HMAC_MD5)
+ md5_start((md5 *)base);
+else
+ sha1_start((hctx *)base);
+}
+
+static void
+chash_mid(int type, void * base, const uschar * string)
+{
+if (type == HMAC_MD5)
+ md5_mid((md5 *)base, string);
+else
+ sha1_mid((hctx *)base, string);
+}
+
+static void
+chash_end(int type, void * base, const uschar * string, int length,
+ uschar * digest)
+{
+if (type == HMAC_MD5)
+ md5_end((md5 *)base, string, length, digest);
+else
+ sha1_end((hctx *)base, string, length, digest);
+}
+
+
+
+
+/* Do an hmac_md5. The result is _not_ nul-terminated, and is sized as
+the smaller of a full hmac_md5 result (16 bytes) or the supplied output buffer.
+
+Arguments:
+ key encoding key, nul-terminated
+ src data to be hashed, nul-terminated
+ buf output buffer
+ len size of output buffer
+*/
+
+static void
+hmac_md5(const uschar * key, const uschar * src, uschar * buf, unsigned len)
+{
+md5 md5_base;
+const uschar * keyptr;
+uschar * p;
+unsigned int keylen;
+
+#define MD5_HASHLEN 16
+#define MD5_HASHBLOCKLEN 64
+
+uschar keyhash[MD5_HASHLEN];
+uschar innerhash[MD5_HASHLEN];
+uschar finalhash[MD5_HASHLEN];
+uschar innerkey[MD5_HASHBLOCKLEN];
+uschar outerkey[MD5_HASHBLOCKLEN];
+
+keyptr = key;
+keylen = Ustrlen(keyptr);
+
+/* If the key is longer than the hash block length, then hash the key
+first */
+
+if (keylen > MD5_HASHBLOCKLEN)
+ {
+ chash_start(HMAC_MD5, &md5_base);
+ chash_end(HMAC_MD5, &md5_base, keyptr, keylen, keyhash);
+ keyptr = keyhash;
+ keylen = MD5_HASHLEN;
+ }
+
+/* Now make the inner and outer key values */
+
+memset(innerkey, 0x36, MD5_HASHBLOCKLEN);
+memset(outerkey, 0x5c, MD5_HASHBLOCKLEN);
+
+for (int i = 0; i < keylen; i++)
+ {
+ innerkey[i] ^= keyptr[i];
+ outerkey[i] ^= keyptr[i];
+ }
+
+/* Now do the hashes */
+
+chash_start(HMAC_MD5, &md5_base);
+chash_mid(HMAC_MD5, &md5_base, innerkey);
+chash_end(HMAC_MD5, &md5_base, src, Ustrlen(src), innerhash);
+
+chash_start(HMAC_MD5, &md5_base);
+chash_mid(HMAC_MD5, &md5_base, outerkey);
+chash_end(HMAC_MD5, &md5_base, innerhash, MD5_HASHLEN, finalhash);
+
+/* Encode the final hash as a hex string, limited by output buffer size */
+
+p = buf;
+for (int i = 0, j = len; i < MD5_HASHLEN; i++)
+ {
+ if (j-- <= 0) break;
+ *p++ = hex_digits[(finalhash[i] & 0xf0) >> 4];
+ if (j-- <= 0) break;
+ *p++ = hex_digits[finalhash[i] & 0x0f];
+ }
+return;
+}
+
+
git://git.exim.org / exim.git / blobdiff