Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 833 insertions, 0 deletions

diff --git a/src/lib/var-expand.c b/src/lib/var-expand.c
new file mode 100644
index 0000000..7ddaec0
--- /dev/null
+++ b/src/lib/var-expand.c
@@ -0,0 +1,833 @@
+/* Copyright (c) 2003-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "array.h"
+#include "md5.h"
+#include "hash.h"
+#include "hex-binary.h"
+#include "base64.h"
+#include "hostpid.h"
+#include "hmac.h"
+#include "pkcs5.h"
+#include "hash-method.h"
+#include "str.h"
+#include "strescape.h"
+#include "var-expand.h"
+#include "var-expand-private.h"
+
+#include <unistd.h>
+#include <ctype.h>
+
+#define TABLE_LAST(t) \
+	((t)->key == '\0' && (t)->long_key == NULL)
+
+struct var_expand_modifier {
+	char key;
+	const char *(*func)(const char *, struct var_expand_context *);
+};
+
+static ARRAY(struct var_expand_extension_func_table) var_expand_extensions;
+
+static const char *
+m_str_lcase(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	return t_str_lcase(str);
+}
+
+static const char *
+m_str_ucase(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	return t_str_ucase(str);
+}
+
+static const char *
+m_str_escape(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	return str_escape(str);
+}
+
+static const char *
+m_str_hex(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	unsigned long long l;
+
+	if (str_to_ullong(str, &l) < 0)
+		l = 0;
+	return t_strdup_printf("%llx", l);
+}
+
+static const char *
+m_str_reverse(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	size_t len = strlen(str);
+	char *p, *rev;
+
+	rev = t_malloc_no0(len + 1);
+	rev[len] = '\0';
+
+	for (p = rev + len - 1; *str != '\0'; str++)
+		*p-- = *str;
+	return rev;
+}
+
+static const char *m_str_hash(const char *str, struct var_expand_context *ctx)
+{
+	unsigned int value = str_hash(str);
+	string_t *hash = t_str_new(20);
+
+	if (ctx->width != 0) {
+		value %= ctx->width;
+		ctx->width = 0;
+	}
+
+	str_printfa(hash, "%x", value);
+	while ((int)str_len(hash) < ctx->offset)
+		str_insert(hash, 0, "0");
+	ctx->offset = 0;
+
+	return str_c(hash);
+}
+
+static const char *
+m_str_newhash(const char *str, struct var_expand_context *ctx)
+{
+	string_t *hash = t_str_new(20);
+	unsigned char result[MD5_RESULTLEN];
+	unsigned int i;
+	uint64_t value = 0;
+
+	md5_get_digest(str, strlen(str), result);
+	for (i = 0; i < sizeof(value); i++) {
+		value <<= 8;
+		value |= result[i];
+	}
+
+	if (ctx->width != 0) {
+		value %= ctx->width;
+		ctx->width = 0;
+	}
+
+	str_printfa(hash, "%x", (unsigned int)value);
+	while ((int)str_len(hash) < ctx->offset)
+		str_insert(hash, 0, "0");
+	ctx->offset = 0;
+
+	return str_c(hash);
+}
+
+static const char *
+m_str_md5(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	unsigned char digest[16];
+
+	md5_get_digest(str, strlen(str), digest);
+
+	return binary_to_hex(digest, sizeof(digest));
+}
+
+static const char *
+m_str_ldap_dn(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	string_t *ret = t_str_new(256);
+
+	while (*str != '\0') {
+		if (*str == '.')
+			str_append(ret, ",dc=");
+		else
+			str_append_c(ret, *str);
+		str++;
+	}
+
+	return str_free_without_data(&ret);
+}
+
+static const char *
+m_str_trim(const char *str, struct var_expand_context *ctx ATTR_UNUSED)
+{
+	size_t len;
+
+	len = strlen(str);
+	while (len > 0 && i_isspace(str[len-1]))
+		len--;
+	return t_strndup(str, len);
+}
+
+#define MAX_MODIFIER_COUNT 10
+static const struct var_expand_modifier modifiers[] = {
+	{ 'L', m_str_lcase },
+	{ 'U', m_str_ucase },
+	{ 'E', m_str_escape },
+	{ 'X', m_str_hex },
+	{ 'R', m_str_reverse },
+	{ 'H', m_str_hash },
+	{ 'N', m_str_newhash },
+	{ 'M', m_str_md5 },
+	{ 'D', m_str_ldap_dn },
+	{ 'T', m_str_trim },
+	{ '\0', NULL }
+};
+
+static int
+var_expand_short(const struct var_expand_table *table, char key,
+		 const char **var_r, const char **error_r)
+{
+	const struct var_expand_table *t;
+
+	if (table != NULL) {
+		for (t = table; !TABLE_LAST(t); t++) {
+			if (t->key == key) {
+				*var_r = t->value != NULL ? t->value : "";
+				return 1;
+			}
+		}
+	}
+
+	/* not found */
+	if (key == '%') {
+		*var_r = "%";
+		return 1;
+	}
+	if (*error_r == NULL)
+		*error_r = t_strdup_printf("Unknown variable '%%%c'", key);
+	*var_r = t_strdup_printf("UNSUPPORTED_VARIABLE_%c", key);
+	return 0;
+}
+
+static int
+var_expand_hash(struct var_expand_context *ctx,
+		const char *key, const char *field,
+		const char **result_r, const char **error_r)
+{
+	enum {
+		FORMAT_HEX,
+		FORMAT_HEX_UC,
+		FORMAT_BASE64
+	} format = FORMAT_HEX;
+
+	const char *p = strchr(key, ';');
+	const char *const *args = NULL;
+	const char *algo = key;
+	const char *value;
+	int ret;
+
+	if (p != NULL) {
+		algo = t_strcut(key, ';');
+		args = t_strsplit(p+1, ",");
+	}
+
+	const struct hash_method *method;
+	if (strcmp(algo, "pkcs5") == 0) {
+		method = hash_method_lookup("sha256");
+	} else if ((method = hash_method_lookup(algo)) == NULL) {
+		return 0;
+	}
+
+	string_t *field_value = t_str_new(64);
+	string_t *salt = t_str_new(64);
+	string_t *tmp = t_str_new(method->digest_size);
+
+	if ((ret = var_expand_long(ctx, field, strlen(field),
+				   &value, error_r)) < 1) {
+		return ret;
+	}
+
+	str_append(field_value, value);
+
+	/* default values */
+	unsigned int rounds = 1;
+	unsigned int truncbits = 0;
+
+	if (strcmp(algo, "pkcs5") == 0) {
+		rounds = 2048;
+		str_append(salt, field);
+	}
+
+	while(args != NULL && *args != NULL) {
+		const char *k = t_strcut(*args, '=');
+		const char *value = strchr(*args, '=');
+		if (value == NULL) {
+			args++;
+			continue;
+		} else {
+			value++;
+		}
+		if (strcmp(k, "rounds") == 0) {
+			if (str_to_uint(value, &rounds)<0) {
+				*error_r = t_strdup_printf(
+					"Cannot parse hash arguments:"
+					"'%s' is not number for rounds",
+					value);
+				return -1;
+			}
+			if (rounds < 1) {
+				*error_r = t_strdup_printf(
+					"Cannot parse hash arguments:"
+					"rounds must be at least 1");
+				return -1;
+			}
+		} else if (strcmp(k, "truncate") == 0) {
+			if (str_to_uint(value, &truncbits)<0) {
+				*error_r = t_strdup_printf(
+					"Cannot parse hash arguments:"
+					"'%s' is not number for truncbits",
+					value);
+				return -1;
+			}
+			truncbits = I_MIN(truncbits, method->digest_size*8);
+		} else if (strcmp(k, "salt") == 0) {
+			str_truncate(salt, 0);
+			if (var_expand_with_funcs(salt, value, ctx->table,
+						  ctx->func_table, ctx->context,
+						  error_r) < 0) {
+				return -1;
+			}
+			break;
+		} else if (strcmp(k, "format") == 0) {
+			if (strcmp(value, "hex") == 0) {
+				format = FORMAT_HEX;
+			} else if (strcmp(value, "hexuc") == 0){
+				format = FORMAT_HEX_UC;
+			} else if (strcmp(value, "base64") == 0) {
+				format = FORMAT_BASE64;
+			} else {
+				*error_r = t_strdup_printf(
+					"Cannot parse hash arguments:"
+					"'%s' is not supported format",
+					value);
+				return -1;
+			}
+		}
+		args++;
+	}
+
+	str_truncate(tmp, 0);
+
+	if (strcmp(algo, "pkcs5") == 0) {
+		if (pkcs5_pbkdf(PKCS5_PBKDF2, method,
+				field_value->data, field_value->used,
+				salt->data, salt->used,
+				rounds, HMAC_MAX_CONTEXT_SIZE, tmp) != 0) {
+			*error_r = "Cannot hash: PKCS5_PBKDF2 failed";
+			return -1;
+		}
+	} else {
+		void *context = t_malloc_no0(method->context_size);
+
+		str_append_str(tmp, field_value);
+
+		for(;rounds>0;rounds--) {
+			method->init(context);
+			if (salt->used > 0)
+				method->loop(context, salt->data, salt->used);
+			method->loop(context, tmp->data, tmp->used);
+			unsigned char *digest =
+				buffer_get_modifiable_data(tmp, NULL);
+			method->result(context, digest);
+			if (tmp->used != method->digest_size)
+				buffer_set_used_size(tmp, method->digest_size);
+		}
+	}
+
+	if (truncbits > 0)
+		buffer_truncate_rshift_bits(tmp, truncbits);
+
+	switch(format) {
+		case FORMAT_HEX:
+			*result_r = binary_to_hex(tmp->data, tmp->used);
+			return 1;
+		case FORMAT_HEX_UC:
+			*result_r = binary_to_hex(tmp->data, tmp->used);
+			return 1;
+		case FORMAT_BASE64: {
+			string_t *dest = t_str_new(64);
+			base64_encode(tmp->data, tmp->used, dest);
+			*result_r = str_c(dest);
+			return 1;
+		}
+	}
+
+	i_unreached();
+}
+
+static int
+var_expand_func(const struct var_expand_func_table *func_table,
+		const char *key, const char *data, void *context,
+		const char **var_r, const char **error_r)
+{
+	const char *value = NULL;
+	int ret;
+
+	if (strcmp(key, "env") == 0) {
+		value = getenv(data);
+		*var_r = value != NULL ? value : "";
+		return 1;
+	}
+	if (func_table != NULL) {
+		for (; func_table->key != NULL; func_table++) {
+			if (strcmp(func_table->key, key) == 0) {
+				ret = func_table->func(data, context, &value, error_r);
+				*var_r = value != NULL ? value : "";
+				return ret;
+			}
+		}
+	}
+	if (*error_r == NULL)
+		*error_r = t_strdup_printf("Unknown variable '%%%s'", key);
+	*var_r = t_strdup_printf("UNSUPPORTED_VARIABLE_%s", key);
+	return 0;
+}
+
+static int
+var_expand_try_extension(struct var_expand_context *ctx,
+			 const char *key, const char *data,
+			 const char **var_r, const char **error_r)
+{
+	int ret;
+	const char *sep = strchr(key, ';');
+
+	if (sep == NULL) sep = key + strlen(key);
+
+	/* try with extensions */
+	const struct var_expand_extension_func_table *f;
+	array_foreach(&var_expand_extensions, f) {
+		/* ensure we won't match abbreviations */
+		size_t len = sep-key;
+		if (strncasecmp(key, f->key, len) == 0 && f->key[len] == '\0')
+			return f->func(ctx, key, data, var_r, error_r);
+	}
+	if ((ret = var_expand_func(ctx->func_table, key, data,
+				   ctx->context, var_r, error_r)) == 0) {
+		*error_r = t_strdup_printf("Unknown variable '%%%s'", key);
+	}
+	return ret;
+}
+
+
+int
+var_expand_long(struct var_expand_context *ctx,
+		const void *key_start, size_t key_len,
+		const char **var_r, const char **error_r)
+{
+	const struct var_expand_table *t;
+	const char *key, *value = NULL;
+	int ret = 1;
+
+	if (ctx->table != NULL) {
+		for (t = ctx->table; !TABLE_LAST(t); t++) {
+			if (t->long_key != NULL &&
+			    strncmp(t->long_key, key_start, key_len) == 0 &&
+			    t->long_key[key_len] == '\0') {
+				*var_r = t->value != NULL ? t->value : "";
+				return 1;
+			}
+		}
+	}
+	key = t_strndup(key_start, key_len);
+
+	/* built-in variables: */
+	switch (key_len) {
+	case 3:
+		if (strcmp(key, "pid") == 0)
+			value = my_pid;
+		else if (strcmp(key, "uid") == 0)
+			value = dec2str(geteuid());
+		else if (strcmp(key, "gid") == 0)
+			value = dec2str(getegid());
+		break;
+	case 8:
+		if (strcmp(key, "hostname") == 0)
+			value = my_hostname;
+		break;
+	}
+
+	if (value == NULL) {
+		const char *data = strchr(key, ':');
+
+		if (data != NULL)
+			key = t_strdup_until(key, data++);
+		else
+			data = "";
+
+		ret = var_expand_try_extension(ctx, key, data, &value, error_r);
+
+		if (ret <= 0 && value == NULL) {
+			value = "";
+		}
+	}
+	*var_r = value;
+	return ret;
+}
+
+int var_expand_with_funcs(string_t *dest, const char *str,
+			  const struct var_expand_table *table,
+			  const struct var_expand_func_table *func_table,
+			  void *context, const char **error_r)
+{
+	const struct var_expand_modifier *m;
+	const char *var;
+	struct var_expand_context ctx;
+	const char *(*modifier[MAX_MODIFIER_COUNT])
+		(const char *, struct var_expand_context *);
+	const char *end;
+	unsigned int i, modifier_count;
+	size_t len;
+	int ret, final_ret = 1;
+
+	*error_r = NULL;
+
+	i_zero(&ctx);
+	ctx.table = table;
+	ctx.func_table = func_table;
+	ctx.context = context;
+
+	for (; *str != '\0'; str++) {
+		if (*str != '%')
+			str_append_c(dest, *str);
+		else {
+			int sign = 1;
+
+			str++;
+
+			/* reset per-field modifiers */
+			ctx.offset = 0;
+			ctx.width = 0;
+			ctx.zero_padding = FALSE;
+
+			/* [<offset>.]<width>[<modifiers>]<variable> */
+			if (*str == '-') {
+				sign = -1;
+				str++;
+			}
+			if (*str == '0') {
+				ctx.zero_padding = TRUE;
+				str++;
+			}
+			while (*str >= '0' && *str <= '9') {
+				ctx.width = ctx.width*10 + (*str - '0');
+				str++;
+			}
+
+			if (*str == '.') {
+				ctx.offset = sign * ctx.width;
+				sign = 1;
+				ctx.width = 0;
+				str++;
+
+				/* if offset was prefixed with zero (or it was
+				   plain zero), just ignore that. zero padding
+				   is done with the width. */
+				ctx.zero_padding = FALSE;
+				if (*str == '0') {
+					ctx.zero_padding = TRUE;
+					str++;
+				}
+				if (*str == '-') {
+					sign = -1;
+					str++;
+				}
+
+				while (*str >= '0' && *str <= '9') {
+					ctx.width = ctx.width*10 + (*str - '0');
+					str++;
+				}
+				ctx.width = sign * ctx.width;
+			}
+
+			modifier_count = 0;
+			while (modifier_count < MAX_MODIFIER_COUNT) {
+				modifier[modifier_count] = NULL;
+				for (m = modifiers; m->key != '\0'; m++) {
+					if (m->key == *str) {
+						/* @UNSAFE */
+						modifier[modifier_count] =
+							m->func;
+						str++;
+						break;
+					}
+				}
+				if (modifier[modifier_count] == NULL)
+					break;
+				modifier_count++;
+			}
+
+			if (*str == '\0')
+				break;
+
+			var = NULL;
+			if (*str == '{' && strchr(str, '}') != NULL) {
+				/* %{long_key} */
+				unsigned int ctr = 1;
+				bool escape = FALSE;
+				end = str;
+				while(*++end != '\0' && ctr > 0) {
+					if (!escape && *end == '\\') {
+						escape = TRUE;
+						continue;
+					}
+					if (escape) {
+						escape = FALSE;
+						continue;
+					}
+					if (*end == '{') ctr++;
+					if (*end == '}') ctr--;
+				}
+				if (ctr == 0)
+					/* it needs to come back a bit */
+					end--;
+				/* if there is no } it will consume rest of the
+				   string */
+				len = end - (str + 1);
+				ret = var_expand_long(&ctx, str+1, len,
+						      &var, error_r);
+				str = end;
+			} else {
+				ret = var_expand_short(ctx.table, *str,
+						       &var, error_r);
+			}
+			i_assert(var != NULL);
+
+			if (final_ret > ret)
+				final_ret = ret;
+
+			if (ret <= 0)
+				str_append(dest, var);
+			else {
+				for (i = 0; i < modifier_count; i++)
+					var = modifier[i](var, &ctx);
+
+				if (ctx.offset < 0) {
+					/* if offset is < 0 then we want to
+					   start at the end */
+					size_t len = strlen(var);
+					size_t offset_from_end = -ctx.offset;
+
+					if (len > offset_from_end)
+						var += len - offset_from_end;
+				} else {
+					while (*var != '\0' && ctx.offset > 0) {
+						ctx.offset--;
+						var++;
+					}
+				}
+				if (ctx.width == 0)
+					str_append(dest, var);
+				else if (!ctx.zero_padding) {
+					if (ctx.width < 0)
+						ctx.width = strlen(var) - (-ctx.width);
+					str_append_max(dest, var, ctx.width);
+				} else {
+					/* %05d -like padding. no truncation. */
+					ssize_t len = strlen(var);
+					while (len < ctx.width) {
+						str_append_c(dest, '0');
+						ctx.width--;
+					}
+					str_append(dest, var);
+				}
+			}
+		}
+	}
+	return final_ret;
+}
+
+int var_expand(string_t *dest, const char *str,
+	       const struct var_expand_table *table, const char **error_r)
+{
+	return var_expand_with_funcs(dest, str, table, NULL, NULL, error_r);
+}
+
+static bool
+var_get_key_range_full(const char *str, unsigned int *idx_r,
+		       unsigned int *size_r)
+{
+	const struct var_expand_modifier *m;
+	unsigned int i = 0;
+
+	/* [<offset>.]<width>[<modifiers>]<variable> */
+	while ((str[i] >= '0' && str[i] <= '9') || str[i] == '-')
+		i++;
+
+	if (str[i] == '.') {
+		i++;
+		while ((str[i] >= '0' && str[i] <= '9') || str[i] == '-')
+			i++;
+	}
+
+	do {
+		for (m = modifiers; m->key != '\0'; m++) {
+			if (m->key == str[i]) {
+				i++;
+				break;
+			}
+		}
+	} while (m->key != '\0');
+
+	if (str[i] != '{') {
+		/* short key */
+		*idx_r = i;
+		*size_r = str[i] == '\0' ? 0 : 1;
+		return FALSE;
+	} else {
+		unsigned int depth = 1;
+		bool escape = FALSE;
+		/* long key */
+		*idx_r = ++i;
+		for (; str[i] != '\0'; i++) {
+			if (!escape && str[i] == '\\') {
+				escape = TRUE;
+				continue;
+			}
+			if (escape) {
+				escape = FALSE;
+				continue;
+			}
+			if (str[i] == '{')
+				depth++;
+			if (str[i] == '}') {
+				if (--depth==0)
+					break;
+			}
+		}
+		*size_r = i - *idx_r;
+		return TRUE;
+	}
+}
+
+char var_get_key(const char *str)
+{
+	unsigned int idx, size;
+
+	if (var_get_key_range_full(str, &idx, &size))
+		return '{';
+	return str[idx];
+}
+
+void var_get_key_range(const char *str, unsigned int *idx_r,
+		       unsigned int *size_r)
+{
+	(void)var_get_key_range_full(str, idx_r, size_r);
+}
+
+static bool var_has_long_key(const char **str, const char *long_key)
+{
+	const char *start, *end;
+
+	start = strchr(*str, '{');
+	i_assert(start != NULL);
+
+	end = strchr(++start, '}');
+	if (end == NULL)
+		return FALSE;
+
+	if (strncmp(start, long_key, end-start) == 0 &&
+	    long_key[end-start] == '\0')
+		return TRUE;
+
+	*str = end;
+	return FALSE;
+}
+
+bool var_has_key(const char *str, char key, const char *long_key)
+{
+	char c;
+
+	for (; *str != '\0'; str++) {
+		if (*str == '%' && str[1] != '\0') {
+			str++;
+			c = var_get_key(str);
+			if (c == key && key != '\0')
+				return TRUE;
+
+			if (c == '{' && long_key != NULL) {
+				if (var_has_long_key(&str, long_key))
+					return TRUE;
+			}
+		}
+	}
+	return FALSE;
+}
+
+void var_expand_extensions_deinit(void)
+{
+	array_free(&var_expand_extensions);
+}
+
+void var_expand_extensions_init(void)
+{
+	i_array_init(&var_expand_extensions, 32);
+
+	/* put all hash methods there */
+	for(const struct hash_method **meth = hash_methods;
+	    *meth != NULL;
+	    meth++) {
+		struct var_expand_extension_func_table *func =
+			array_append_space(&var_expand_extensions);
+		func->key = (*meth)->name;
+		func->func = var_expand_hash;
+	}
+
+	/* pkcs5 */
+	struct var_expand_extension_func_table *func =
+		array_append_space(&var_expand_extensions);
+	func->key = "pkcs5";
+	func->func = var_expand_hash;
+
+	/* if */
+	func = array_append_space(&var_expand_extensions);
+	func->key = "if";
+	func->func = var_expand_if;
+}
+
+void
+var_expand_register_func_array(const struct var_expand_extension_func_table *funcs)
+{
+	for(const struct var_expand_extension_func_table *ptr = funcs;
+	    ptr->key != NULL;
+	    ptr++) {
+		i_assert(*ptr->key != '\0');
+		array_push_front(&var_expand_extensions, ptr);
+	}
+}
+
+void
+var_expand_unregister_func_array(const struct var_expand_extension_func_table *funcs)
+{
+	for(const struct var_expand_extension_func_table *ptr = funcs;
+	    ptr->key != NULL;
+	    ptr++) {
+		i_assert(ptr->func != NULL);
+		for(unsigned int i = 0; i < array_count(&var_expand_extensions); i++) {
+			const struct var_expand_extension_func_table *func =
+				array_idx(&var_expand_extensions, i);
+			if (strcasecmp(func->key, ptr->key) == 0) {
+				array_delete(&var_expand_extensions, i, 1);
+			}
+		}
+	}
+}
+
+struct var_expand_table *
+var_expand_merge_tables(pool_t pool, const struct var_expand_table *a,
+			const struct var_expand_table *b)
+{
+	ARRAY(struct var_expand_table) table;
+	size_t a_size = var_expand_table_size(a);
+	size_t b_size = var_expand_table_size(b);
+	p_array_init(&table, pool, a_size + b_size + 1);
+	for(size_t i=0; i<a_size; i++) {
+		struct var_expand_table *entry =
+			array_append_space(&table);
+		entry->key = a[i].key;
+		entry->value = p_strdup(pool, a[i].value);
+		entry->long_key = p_strdup(pool, a[i].long_key);
+	}
+	for(size_t i=0; i<b_size; i++) {
+		struct var_expand_table *entry =
+			array_append_space(&table);
+		entry->key = b[i].key;
+		entry->value = p_strdup(pool, b[i].value);
+		entry->long_key = p_strdup(pool, b[i].long_key);
+	}
+	array_append_zero(&table);
+	return array_front_modifiable(&table);
+}