diff options
Diffstat (limited to 'libfreerdp/crypto/base64.c')
| -rw-r--r-- | libfreerdp/crypto/base64.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/libfreerdp/crypto/base64.c b/libfreerdp/crypto/base64.c new file mode 100644 index 0000000..683d297 --- /dev/null +++ b/libfreerdp/crypto/base64.c @@ -0,0 +1,250 @@ +/** + * FreeRDP: A Remote Desktop Protocol Implementation + * Base64 Encoding & Decoding + * + * Copyright 2011-2012 Marc-Andre Moreau <marcandre.moreau@gmail.com> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <freerdp/config.h> + +#include <winpr/crt.h> + +#include <freerdp/crypto/crypto.h> + +static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +static const char base64url[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; + +static char* base64_encode_ex(const char* alphabet, const BYTE* data, size_t length, BOOL pad, + BOOL crLf, size_t lineSize) +{ + int c = 0; + const BYTE* q = NULL; + char* p = NULL; + char* ret = NULL; + int blocks = 0; + size_t outLen = (length + 3) * 4 / 3; + size_t extra = 0; + if (crLf) + { + size_t nCrLf = (outLen + lineSize - 1) / lineSize; + extra = nCrLf * 2; + } + size_t outCounter = 0; + + q = data; + p = ret = (char*)malloc(outLen + extra + 1ull); + if (!p) + return NULL; + + /* b1, b2, b3 are input bytes + * + * 0 1 2 + * 012345678901234567890123 + * | b1 | b2 | b3 | + * + * [ c1 ] [ c3 ] + * [ c2 ] [ c4 ] + * + * c1, c2, c3, c4 are output chars in base64 + */ + + /* first treat complete blocks */ + blocks = length - (length % 3); + for (int i = 0; i < blocks; i += 3, q += 3) + { + c = (q[0] << 16) + (q[1] << 8) + q[2]; + + *p++ = alphabet[(c & 0x00FC0000) >> 18]; + *p++ = alphabet[(c & 0x0003F000) >> 12]; + *p++ = alphabet[(c & 0x00000FC0) >> 6]; + *p++ = alphabet[c & 0x0000003F]; + + outCounter += 4; + if (crLf && (outCounter % lineSize == 0)) + { + *p++ = '\r'; + *p++ = '\n'; + } + } + + /* then remainder */ + switch (length % 3) + { + case 0: + break; + case 1: + c = (q[0] << 16); + *p++ = alphabet[(c & 0x00FC0000) >> 18]; + *p++ = alphabet[(c & 0x0003F000) >> 12]; + if (pad) + { + *p++ = '='; + *p++ = '='; + } + break; + case 2: + c = (q[0] << 16) + (q[1] << 8); + *p++ = alphabet[(c & 0x00FC0000) >> 18]; + *p++ = alphabet[(c & 0x0003F000) >> 12]; + *p++ = alphabet[(c & 0x00000FC0) >> 6]; + if (pad) + *p++ = '='; + break; + } + + if (crLf && length % 3) + { + *p++ = '\r'; + *p++ = '\n'; + } + *p = 0; + + return ret; +} + +static char* base64_encode(const char* alphabet, const BYTE* data, size_t length, BOOL pad) +{ + return base64_encode_ex(alphabet, data, length, pad, FALSE, 64); +} + +static int base64_decode_char(const char* alphabet, char c) +{ + char* p = NULL; + + if (c == '\0') + return -1; + + if ((p = strchr(alphabet, c))) + return p - alphabet; + + return -1; +} + +static void* base64_decode(const char* alphabet, const char* s, size_t length, size_t* data_len, + BOOL pad) +{ + int n[4]; + BYTE* q = NULL; + BYTE* data = NULL; + size_t nBlocks = 0; + size_t outputLen = 0; + int remainder = length % 4; + + if ((pad && remainder > 0) || (remainder == 1)) + return NULL; + + if (!pad && remainder) + length += 4 - remainder; + + q = data = (BYTE*)malloc(length / 4 * 3 + 1); + if (!q) + return NULL; + + /* first treat complete blocks */ + nBlocks = (length / 4); + outputLen = 0; + + if (nBlocks < 1) + { + free(data); + return NULL; + } + + for (size_t i = 0; i < nBlocks - 1; i++, q += 3) + { + n[0] = base64_decode_char(alphabet, *s++); + n[1] = base64_decode_char(alphabet, *s++); + n[2] = base64_decode_char(alphabet, *s++); + n[3] = base64_decode_char(alphabet, *s++); + + if ((n[0] == -1) || (n[1] == -1) || (n[2] == -1) || (n[3] == -1)) + goto out_free; + + q[0] = (n[0] << 2) + (n[1] >> 4); + q[1] = ((n[1] & 15) << 4) + (n[2] >> 2); + q[2] = ((n[2] & 3) << 6) + n[3]; + outputLen += 3; + } + + /* treat last block */ + n[0] = base64_decode_char(alphabet, *s++); + n[1] = base64_decode_char(alphabet, *s++); + if ((n[0] == -1) || (n[1] == -1)) + goto out_free; + + n[2] = remainder == 2 ? -1 : base64_decode_char(alphabet, *s++); + n[3] = remainder >= 2 ? -1 : base64_decode_char(alphabet, *s++); + + q[0] = (n[0] << 2) + (n[1] >> 4); + if (n[2] == -1) + { + /* XX== */ + outputLen += 1; + if (n[3] != -1) + goto out_free; + + q[1] = ((n[1] & 15) << 4); + } + else if (n[3] == -1) + { + /* yyy= */ + outputLen += 2; + q[1] = ((n[1] & 15) << 4) + (n[2] >> 2); + q[2] = ((n[2] & 3) << 6); + } + else + { + /* XXXX */ + outputLen += 3; + q[0] = (n[0] << 2) + (n[1] >> 4); + q[1] = ((n[1] & 15) << 4) + (n[2] >> 2); + q[2] = ((n[2] & 3) << 6) + n[3]; + } + + if (data_len) + *data_len = outputLen; + data[outputLen] = '\0'; + + return data; +out_free: + free(data); + return NULL; +} + +char* crypto_base64_encode_ex(const BYTE* data, size_t length, BOOL withCrLf) +{ + return base64_encode_ex(base64, data, length, TRUE, withCrLf, 64); +} + +char* crypto_base64_encode(const BYTE* data, size_t length) +{ + return base64_encode(base64, data, length, TRUE); +} + +void crypto_base64_decode(const char* enc_data, size_t length, BYTE** dec_data, size_t* res_length) +{ + *dec_data = base64_decode(base64, enc_data, length, res_length, TRUE); +} + +char* crypto_base64url_encode(const BYTE* data, size_t length) +{ + return base64_encode(base64url, data, length, FALSE); +} + +void crypto_base64url_decode(const char* enc_data, size_t length, BYTE** dec_data, + size_t* res_length) +{ + *dec_data = base64_decode(base64url, enc_data, length, res_length, FALSE); +} |