Add two helpers: one to represent a binary data as a string of hexadecimal values, and one to restore a such string into its original binary data.
Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> --- include/qemu/cutils.h | 33 ++++++++++++++++++++++++++ util/cutils.c | 55 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+) diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h index d2dad3057c..375a5508b0 100644 --- a/include/qemu/cutils.h +++ b/include/qemu/cutils.h @@ -171,6 +171,39 @@ bool test_buffer_is_zero_next_accel(void); int uleb128_encode_small(uint8_t *out, uint32_t n); int uleb128_decode_small(const uint8_t *in, uint32_t *n); +/** + * qemu_strdup_hexlify: + * + * Encode a sequence of binary data into its hexadecimal stringified + * representation. + * + * @ptr: Buffer to hexlify + * @size: Length of the buffer + * + * Use qemu_strdup_unhexlify() to convert the hex string to original data. + * + * Returns: A newly allocated, zero-terminated hex encoded string representing + * the data. The returned string must be freed with g_free(). + */ +gchar *qemu_strdup_hexlify(gconstpointer ptr, gsize size); + +/** + * qemu_strdup_unhexlify: + * + * Decode a sequence of hexadecimal encoded text into binary data. + * + * @hex_string: String to unhexlify + * @out_size: if not NULL: gsize to be written with the data length + * + * This function is the opposite of qemu_strdup_hexlify(). + * + * Returns: A newly allocated buffer containing the binary data that text + * represents. The returned buffer must be freed with g_free(). + * Note that the returned binary data is not necessarily zero-terminated, + * so it should not be used as a character string. + */ +gpointer qemu_strdup_unhexlify(const gchar *hex_string, gsize *out_size); + /** * qemu_pstrcmp0: * @str1: a non-NULL pointer to a C string (*str1 can be NULL) diff --git a/util/cutils.c b/util/cutils.c index e098debdc0..bf324c0d8b 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -779,6 +779,61 @@ int uleb128_decode_small(const uint8_t *in, uint32_t *n) } } +static guchar hexval(const gchar v) +{ + switch (v) { + case '0' ... '9': + return v - '0'; + case 'A' ... 'F': + return v - 'A' + 10; + case 'a' ... 'f': + return v - 'a' + 10; + default: + return 0; + } +} + +gchar *qemu_strdup_hexlify(gconstpointer ptr, gsize len) +{ + guchar *data = (guchar *)ptr; + gchar *hex_string; + + if (!ptr || !len) { + return g_strdup(""); + } + + hex_string = g_malloc(2 * len + 1); + for (gsize i = 0; i < len; i++) { + g_snprintf(&hex_string[2 * i], 3, "%02x", data[i]); + } + + return hex_string; +} + +gpointer qemu_strdup_unhexlify(const gchar *hex_string, gsize *out_size) +{ + size_t size = 0; + guchar *data = NULL; + + if (hex_string) { + size = strlen(hex_string) / 2; + if (size) { + size_t i; + + data = g_new(guchar, size + 1); + for (i = 0; i < size; i++) { + data[i] = hexval(*hex_string++) << 4; + data[i] |= hexval(*hex_string++); + } + data[i] = '\0'; + } + } + if (out_size) { + *out_size = size; + } + return data; +} + /* * helper to parse debug environment variables */ -- 2.20.1