diff --git a/library/x509.c b/library/x509.c index f44860bfe..e2bb2fd9c 100644 --- a/library/x509.c +++ b/library/x509.c @@ -826,8 +826,8 @@ static char nibble_to_hex_digit(int i) int mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn) { int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED; - size_t i, j, n, asn1_len_size, asn1_len_start; - unsigned char asn1_len_buf[5]; + size_t i, j, n, asn1_len_size, asn1_tag_size, asn1_tag_len_buf_start; + unsigned char asn1_tag_len_buf[10]; unsigned char *asn1_len_p; unsigned char c, merge = 0; const mbedtls_x509_name *name; @@ -874,28 +874,29 @@ int mbedtls_x509_dn_gets(char *buf, size_t size, const mbedtls_x509_name *dn) #if defined(MBEDTLS_ASN1_WRITE_C) s[0] = '#'; - c = name->val.tag; - lowbits = (c & 0x0F); - highbits = c >> 4; - s[1] = nibble_to_hex_digit(highbits); - s[2] = nibble_to_hex_digit(lowbits); - - asn1_len_p = asn1_len_buf+5; - asn1_len_size = mbedtls_asn1_write_len(&asn1_len_p, asn1_len_buf, name->val.len); - asn1_len_start = 5 - asn1_len_size; - for (i = 0, j = 3; i < asn1_len_size + name->val.len; i++, j++) { + asn1_len_p = asn1_tag_len_buf + 10; + asn1_len_size = mbedtls_asn1_write_len(&asn1_len_p, asn1_tag_len_buf, name->val.len); + asn1_tag_size = mbedtls_asn1_write_tag(&asn1_len_p,asn1_tag_len_buf,name->val.tag); + asn1_tag_len_buf_start = 10 - asn1_len_size - asn1_tag_size; + for (i = 0, j = 1; i < asn1_len_size + asn1_tag_size; i++) { if (j + 1 >= sizeof(s) - 1) { return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL; } - if (i < asn1_len_size) { - c = asn1_len_buf[asn1_len_start+i]; - } else { - c = name->val.p[i-asn1_len_size]; - } + c = asn1_tag_len_buf[asn1_tag_len_buf_start+i]; lowbits = (c & 0x0F); highbits = c >> 4; s[j++] = nibble_to_hex_digit(highbits); - s[j] = nibble_to_hex_digit(lowbits); + s[j++] = nibble_to_hex_digit(lowbits); + } + for (i = 0; i < name->val.len; i++) { + if (j + 1 >= sizeof(s) - 1) { + return MBEDTLS_ERR_X509_BUFFER_TOO_SMALL; + } + c = name->val.p[i]; + lowbits = (c & 0x0F); + highbits = c >> 4; + s[j++] = nibble_to_hex_digit(highbits); + s[j++] = nibble_to_hex_digit(lowbits); } #else return MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE;