add the apache md5 implementation to valid password hash algorithms

Conflicts:
	src/util/password.c
	src/util/password.h

crypto

@@ -1 +1 @@
-Subproject commit f9ecf5a10983adfc7bd1bee8ac1f9a3abf1d41d9
+Subproject commit 10f60eafb8cbb4f6af2a4df65371e12464c2fd45

src/util/password.c

@@ -0,0 +1,99 @@
+#include <platform.h>
+#include "password.h"
+
+#include <md5.h>
+#include <mtrand.h>
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <time.h>
+
+#define MAXSALTLEN 32 // maximum length in characters of any salt
+#define SALTLEN 8 // length of salts we generate
+
+#define b64_from_24bit(B2, B1, B0, N)					      \
+  do {									      \
+    unsigned int w = ((B2) << 16) | ((B1) << 8) | (B0);			      \
+    int n = (N);							      \
+    while (n-- > 0 && buflen > 0)					      \
+      {									      \
+	*cp++ = itoa64[w & 0x3f];					      \
+	--buflen;							      \
+	w >>= 6;							      \
+      }									      \
+  } while (0)
+
+
+char *password_gensalt(void) {
+    static char salt[SALTLEN + 1];
+    char *cp = salt;
+    int buflen = SALTLEN;
+    while (buflen) {
+        unsigned long ul = genrand_int32() & (unsigned long)time(0);
+        b64_from_24bit((char)(ul & 0xFF), (char)((ul>>8)&0xff), (char)((ul>>16)&0xFF), 4);
+    }
+    salt[SALTLEN] = 0;
+    return salt;
+}
+
+static const char * password_hash_i(const char * passwd, const char *salt, int algo, char *result, size_t len) {
+    assert(passwd);
+    if (!salt) {
+        salt = password_gensalt();
+    }
+    if (algo==PASSWORD_PLAIN) {
+        _snprintf(result, len, "$0$%s$%s", salt, passwd);
+    }
+    else if (algo == PASSWORD_MD5) {
+        return md5_crypt_r(passwd, salt, result, len);
+    }
+    else if (algo == PASSWORD_APACHE_MD5) {
+        apr_md5_encode(passwd, salt, result, len);
+        return result;
+    }
+    else {
+        return NULL;
+    }
+    return result;
+}
+
+const char * password_hash(const char * passwd, const char * salt, int algo) {
+    static char result[64]; // TODO: static result buffers are bad mojo!
+    if (algo < 0) algo = PASSWORD_DEFAULT;
+    return password_hash_i(passwd, salt, algo, result, sizeof(result));
+}
+
+static bool password_is_implemented(int algo) {
+    return algo==PASSWORD_PLAIN || algo==PASSWORD_MD5 || algo==PASSWORD_APACHE_MD5;
+}
+
+int password_verify(const char * pwhash, const char * passwd) {
+    char salt[MAXSALTLEN+1];
+    char hash[64];
+    size_t len;
+    int algo;
+    char *pos;
+    const char *dol, *result;
+    assert(passwd);
+    assert(pwhash);
+    assert(pwhash[0] == '$');
+    algo = pwhash[1];
+    pos = strchr(pwhash+2, '$');
+    assert(pos && pos[0] == '$');
+    ++pos;
+    dol = strchr(pos, '$');
+    assert(dol>pos && dol[0] == '$');
+    len = dol - pos;
+    assert(len <= MAXSALTLEN);
+    strncpy(salt, pos, len);
+    salt[len] = 0;
+    result = password_hash_i(passwd, salt, algo, hash, sizeof(hash));
+    if (!password_is_implemented(algo)) {
+        return VERIFY_UNKNOWN;
+    }
+    if (strcmp(pwhash, result) == 0) {
+        return VERIFY_OK;
+    }
+    return VERIFY_FAIL;
+}

src/util/password.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#define PASSWORD_PLAIN  '0'
+#define PASSWORD_MD5 '1'
+#define PASSWORD_BCRYPT '2' // not implemented
+#define PASSWORD_APACHE_MD5 'a'
+#define PASSWORD_SHA256 '5' // not implemented
+#define PASSWORD_SHA512 '6' // not implemented
+#define PASSWORD_DEFAULT PASSWORD_MD5
+
+
+#define VERIFY_OK 0 // password matches hash
+#define VERIFY_FAIL 1 // password is wrong
+#define VERIFY_UNKNOWN 2 // hashing algorithm not supported
+int password_verify(const char *hash, const char *passwd);
+const char * password_hash(const char *passwd, const char *salt, int algo);