1Fix integer overflows. Will not work on compilers with unsigned char 2as the default. 3 4Fetched from: https://sources.debian.org/patches/libb64/1.2-5/ 5 6Combined "integer overflows.diff" and "off by one.diff" and adapted 7for version 1.2.1. 8 9Signed-off-by: Mikael Eliasson <mikael@robomagi.com> 10 11diff --git a/src/cdecode.c b/src/cdecode.c 12index a6c0a42..45da4e1 100644 13--- a/src/cdecode.c 14+++ b/src/cdecode.c 15@@ -9,10 +9,11 @@ For details, see http://sourceforge.net/projects/libb64 16 17 int base64_decode_value(char value_in) 18 { 19- static const char decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51}; 20+ static const signed char decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51}; 21 static const char decoding_size = sizeof(decoding); 22+ if (value_in < 43) return -1; 23 value_in -= 43; 24- if (value_in < 0 || value_in >= decoding_size) return -1; 25+ if (value_in >= decoding_size) return -1; 26 return decoding[(int)value_in]; 27 } 28 29@@ -26,7 +27,7 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex 30 { 31 const char* codechar = code_in; 32 char* plainchar = plaintext_out; 33- char fragment; 34+ int fragment; 35 36 *plainchar = state_in->plainchar; 37 38@@ -42,7 +43,7 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex 39 state_in->plainchar = *plainchar; 40 return plainchar - plaintext_out; 41 } 42- fragment = (char)base64_decode_value(*codechar++); 43+ fragment = base64_decode_value(*codechar++); 44 } while (fragment < 0); 45 *plainchar = (fragment & 0x03f) << 2; 46 case step_b: 47@@ -53,7 +54,7 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex 48 state_in->plainchar = *plainchar; 49 return plainchar - plaintext_out; 50 } 51- fragment = (char)base64_decode_value(*codechar++); 52+ fragment = base64_decode_value(*codechar++); 53 } while (fragment < 0); 54 *plainchar++ |= (fragment & 0x030) >> 4; 55 *plainchar = (fragment & 0x00f) << 4; 56@@ -65,7 +66,7 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex 57 state_in->plainchar = *plainchar; 58 return plainchar - plaintext_out; 59 } 60- fragment = (char)base64_decode_value(*codechar++); 61+ fragment = base64_decode_value(*codechar++); 62 } while (fragment < 0); 63 *plainchar++ |= (fragment & 0x03c) >> 2; 64 *plainchar = (fragment & 0x003) << 6; 65@@ -77,7 +78,7 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex 66 state_in->plainchar = *plainchar; 67 return plainchar - plaintext_out; 68 } 69- fragment = (char)base64_decode_value(*codechar++); 70+ fragment = base64_decode_value(*codechar++); 71 } while (fragment < 0); 72 *plainchar++ |= (fragment & 0x03f); 73 } 74