1 files changed, 226 insertions, 39 deletions

diff --git a/thirdparty/mbedtls/library/x509_create.c b/thirdparty/mbedtls/library/x509_create.c
index 4ffd3b6a80..839b5df226 100644
--- a/thirdparty/mbedtls/library/x509_create.c
+++ b/thirdparty/mbedtls/library/x509_create.c
@@ -9,13 +9,17 @@
 
 #if defined(MBEDTLS_X509_CREATE_C)
 
-#include "mbedtls/x509.h"
+#include "x509_internal.h"
 #include "mbedtls/asn1write.h"
 #include "mbedtls/error.h"
 #include "mbedtls/oid.h"
 
 #include <string.h>
 
+#include "mbedtls/platform.h"
+
+#include "mbedtls/asn1.h"
+
 /* Structure linking OIDs for X.509 DN AttributeTypes to their
  * string representations and default string encodings used by Mbed TLS. */
 typedef struct {
@@ -23,7 +27,8 @@ typedef struct {
                        * "CN" or "emailAddress". */
     size_t name_len; /* Length of 'name', without trailing 0 byte. */
     const char *oid; /* String representation of OID of AttributeType,
-                      * as per RFC 5280, Appendix A.1. */
+                      * as per RFC 5280, Appendix A.1. encoded as per
+                      * X.690 */
     int default_tag; /* The default character encoding used for the
                       * given attribute type, e.g.
                       * MBEDTLS_ASN1_UTF8_STRING for UTF-8. */
@@ -111,79 +116,261 @@ static const x509_attr_descriptor_t *x509_attr_descr_from_name(const char *name,
     return cur;
 }
 
+static int hex_to_int(char c)
+{
+    return ('0' <= c && c <= '9') ? (c - '0') :
+           ('a' <= c && c <= 'f') ? (c - 'a' + 10) :
+           ('A' <= c && c <= 'F') ? (c - 'A' + 10) : -1;
+}
+
+static int hexpair_to_int(const char *hexpair)
+{
+    int n1 = hex_to_int(*hexpair);
+    int n2 = hex_to_int(*(hexpair + 1));
+
+    if (n1 != -1 && n2 != -1) {
+        return (n1 << 4) | n2;
+    } else {
+        return -1;
+    }
+}
+
+static int parse_attribute_value_string(const char *s,
+                                        int len,
+                                        unsigned char *data,
+                                        size_t *data_len)
+{
+    const char *c;
+    const char *end = s + len;
+    unsigned char *d = data;
+    int n;
+
+    for (c = s; c < end; c++) {
+        if (*c == '\\') {
+            c++;
+
+            /* Check for valid escaped characters as per RFC 4514 Section 3 */
+            if (c + 1 < end && (n = hexpair_to_int(c)) != -1) {
+                if (n == 0) {
+                    return MBEDTLS_ERR_X509_INVALID_NAME;
+                }
+                *(d++) = n;
+                c++;
+            } else if (c < end && strchr(" ,=+<>#;\"\\", *c)) {
+                *(d++) = *c;
+            } else {
+                return MBEDTLS_ERR_X509_INVALID_NAME;
+            }
+        } else {
+            *(d++) = *c;
+        }
+
+        if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) {
+            return MBEDTLS_ERR_X509_INVALID_NAME;
+        }
+    }
+    *data_len = (size_t) (d - data);
+    return 0;
+}
+
+/** Parse a hexstring containing a DER-encoded string.
+ *
+ * \param s         A string of \p len bytes hexadecimal digits.
+ * \param len       Number of bytes to read from \p s.
+ * \param data      Output buffer of size \p data_size.
+ *                  On success, it contains the payload that's DER-encoded
+ *                  in the input (content without the tag and length).
+ *                  If the DER tag is a string tag, the payload is guaranteed
+ *                  not to contain null bytes.
+ * \param data_size Length of the \p data buffer.
+ * \param data_len  On success, the length of the parsed string.
+ *                  It is guaranteed to be less than
+ *                  #MBEDTLS_X509_MAX_DN_NAME_SIZE.
+ * \param tag       The ASN.1 tag that the payload in \p data is encoded in.
+ *
+ * \retval          0 on success.
+ * \retval          #MBEDTLS_ERR_X509_INVALID_NAME if \p s does not contain
+ *                  a valid hexstring,
+ *                  or if the decoded hexstring is not valid DER,
+ *                  or if the payload does not fit in \p data,
+ *                  or if the payload is more than
+ *                  #MBEDTLS_X509_MAX_DN_NAME_SIZE bytes,
+ *                  of if \p *tag is an ASN.1 string tag and the payload
+ *                  contains a null byte.
+ * \retval          #MBEDTLS_ERR_X509_ALLOC_FAILED on low memory.
+ */
+static int parse_attribute_value_hex_der_encoded(const char *s,
+                                                 size_t len,
+                                                 unsigned char *data,
+                                                 size_t data_size,
+                                                 size_t *data_len,
+                                                 int *tag)
+{
+    /* Step 1: preliminary length checks. */
+    /* Each byte is encoded by exactly two hexadecimal digits. */
+    if (len % 2 != 0) {
+        /* Odd number of hex digits */
+        return MBEDTLS_ERR_X509_INVALID_NAME;
+    }
+    size_t const der_length = len / 2;
+    if (der_length > MBEDTLS_X509_MAX_DN_NAME_SIZE + 4) {
+        /* The payload would be more than MBEDTLS_X509_MAX_DN_NAME_SIZE
+         * (after subtracting the ASN.1 tag and length). Reject this early
+         * to avoid allocating a large intermediate buffer. */
+        return MBEDTLS_ERR_X509_INVALID_NAME;
+    }
+    if (der_length < 1) {
+        /* Avoid empty-buffer shenanigans. A valid DER encoding is never
+         * empty. */
+        return MBEDTLS_ERR_X509_INVALID_NAME;
+    }
+
+    /* Step 2: Decode the hex string into an intermediate buffer. */
+    unsigned char *der = mbedtls_calloc(1, der_length);
+    if (der == NULL) {
+        return MBEDTLS_ERR_X509_ALLOC_FAILED;
+    }
+    /* Beyond this point, der needs to be freed on exit. */
+    for (size_t i = 0; i < der_length; i++) {
+        int c = hexpair_to_int(s + 2 * i);
+        if (c < 0) {
+            goto error;
+        }
+        der[i] = c;
+    }
+
+    /* Step 3: decode the DER. */
+    /* We've checked that der_length >= 1 above. */
+    *tag = der[0];
+    {
+        unsigned char *p = der + 1;
+        if (mbedtls_asn1_get_len(&p, der + der_length, data_len) != 0) {
+            goto error;
+        }
+        /* Now p points to the first byte of the payload inside der,
+         * and *data_len is the length of the payload. */
+
+        /* Step 4: payload validation */
+        if (*data_len > MBEDTLS_X509_MAX_DN_NAME_SIZE) {
+            goto error;
+        }
+        /* Strings must not contain null bytes. */
+        if (MBEDTLS_ASN1_IS_STRING_TAG(*tag)) {
+            for (size_t i = 0; i < *data_len; i++) {
+                if (p[i] == 0) {
+                    goto error;
+                }
+            }
+        }
+
+        /* Step 5: output the payload. */
+        if (*data_len > data_size) {
+            goto error;
+        }
+        memcpy(data, p, *data_len);
+    }
+    mbedtls_free(der);
+
+    return 0;
+
+error:
+    mbedtls_free(der);
+    return MBEDTLS_ERR_X509_INVALID_NAME;
+}
+
 int mbedtls_x509_string_to_names(mbedtls_asn1_named_data **head, const char *name)
 {
     int ret = MBEDTLS_ERR_X509_INVALID_NAME;
+    int parse_ret = 0;
     const char *s = name, *c = s;
     const char *end = s + strlen(s);
-    const char *oid = NULL;
+    mbedtls_asn1_buf oid = { .p = NULL, .len = 0, .tag = MBEDTLS_ASN1_NULL };
     const x509_attr_descriptor_t *attr_descr = NULL;
-    int in_tag = 1;
-    char data[MBEDTLS_X509_MAX_DN_NAME_SIZE];
-    char *d = data;
+    int in_attr_type = 1;
+    int tag;
+    int numericoid = 0;
+    unsigned char data[MBEDTLS_X509_MAX_DN_NAME_SIZE];
+    size_t data_len = 0;
 
     /* Clear existing chain if present */
     mbedtls_asn1_free_named_data_list(head);
 
     while (c <= end) {
-        if (in_tag && *c == '=') {
-            if ((attr_descr = x509_attr_descr_from_name(s, c - s)) == NULL) {
-                ret = MBEDTLS_ERR_X509_UNKNOWN_OID;
-                goto exit;
+        if (in_attr_type && *c == '=') {
+            if ((attr_descr = x509_attr_descr_from_name(s, (size_t) (c - s))) == NULL) {
+                if ((mbedtls_oid_from_numeric_string(&oid, s, (size_t) (c - s))) != 0) {
+                    return MBEDTLS_ERR_X509_INVALID_NAME;
+                } else {
+                    numericoid = 1;
+                }
+            } else {
+                oid.len = strlen(attr_descr->oid);
+                oid.p = mbedtls_calloc(1, oid.len);
+                memcpy(oid.p, attr_descr->oid, oid.len);
+                numericoid = 0;
             }
 
-            oid = attr_descr->oid;
             s = c + 1;
-            in_tag = 0;
-            d = data;
+            in_attr_type = 0;
         }
 
-        if (!in_tag && *c == '\\' && c != end) {
-            c++;
-
-            /* Check for valid escaped characters */
-            if (c == end || *c != ',') {
-                ret = MBEDTLS_ERR_X509_INVALID_NAME;
-                goto exit;
+        if (!in_attr_type && ((*c == ',' && *(c-1) != '\\') || c == end)) {
+            if (s == c) {
+                mbedtls_free(oid.p);
+                return MBEDTLS_ERR_X509_INVALID_NAME;
+            } else if (*s == '#') {
+                /* We know that c >= s (loop invariant) and c != s (in this
+                 * else branch), hence c - s - 1 >= 0. */
+                parse_ret = parse_attribute_value_hex_der_encoded(
+                    s + 1, (size_t) (c - s) - 1,
+                    data, sizeof(data), &data_len, &tag);
+                if (parse_ret != 0) {
+                    mbedtls_free(oid.p);
+                    return parse_ret;
+                }
+            } else {
+                if (numericoid) {
+                    mbedtls_free(oid.p);
+                    return MBEDTLS_ERR_X509_INVALID_NAME;
+                } else {
+                    if ((parse_ret =
+                             parse_attribute_value_string(s, (int) (c - s), data,
+                                                          &data_len)) != 0) {
+                        mbedtls_free(oid.p);
+                        return parse_ret;
+                    }
+                    tag = attr_descr->default_tag;
+                }
             }
-        } else if (!in_tag && (*c == ',' || c == end)) {
+
             mbedtls_asn1_named_data *cur =
-                mbedtls_asn1_store_named_data(head, oid, strlen(oid),
+                mbedtls_asn1_store_named_data(head, (char *) oid.p, oid.len,
                                               (unsigned char *) data,
-                                              d - data);
-
+                                              data_len);
+            mbedtls_free(oid.p);
+            oid.p = NULL;
             if (cur == NULL) {
                 return MBEDTLS_ERR_X509_ALLOC_FAILED;
             }
 
             // set tagType
-            cur->val.tag = attr_descr->default_tag;
+            cur->val.tag = tag;
 
             while (c < end && *(c + 1) == ' ') {
                 c++;
             }
 
             s = c + 1;
-            in_tag = 1;
+            in_attr_type = 1;
 
             /* Successfully parsed one name, update ret to success */
             ret = 0;
         }
-
-        if (!in_tag && s != c + 1) {
-            *(d++) = *c;
-
-            if (d - data == MBEDTLS_X509_MAX_DN_NAME_SIZE) {
-                ret = MBEDTLS_ERR_X509_INVALID_NAME;
-                goto exit;
-            }
-        }
-
         c++;
     }
-
-exit:
-
+    if (oid.p != NULL) {
+        mbedtls_free(oid.p);
+    }
     return ret;
 }