The Tor Browser: security/nss/lib/util/dersubr.c@b8a032363ba2 (annotated)

security/nss/lib/util/dersubr.c@b8a032363ba2 (annotated)

security/nss/lib/util/dersubr.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "secder.h"
 #include <limits.h>
 #include "secerr.h"
 int
 DER_LengthLength(PRUint32 len)
 {
     if (len > 127) {
 	if (len > 255) {
 	    if (len > 65535L) {
 		if (len > 16777215L) {
 		    return 5;
 		} else {
 		    return 4;
 		}
 	    } else {
 		return 3;
 	    }
 	} else {
 	    return 2;
 	}
     } else {
 	return 1;
     }
 }
 unsigned char *
 DER_StoreHeader(unsigned char *buf, unsigned int code, PRUint32 len)
 {
     unsigned char b[4];
     b[0] = (unsigned char)(len >> 24);
     b[1] = (unsigned char)(len >> 16);
     b[2] = (unsigned char)(len >> 8);
     b[3] = (unsigned char)len;
     if ((code & DER_TAGNUM_MASK) == DER_SET
 	|| (code & DER_TAGNUM_MASK) == DER_SEQUENCE)
 	code |= DER_CONSTRUCTED;
     *buf++ = code;
     if (len > 127) {
 	if (len > 255) {
 	    if (len > 65535) {
 		if (len > 16777215) {
 		    *buf++ = 0x84;
 		    *buf++ = b[0];
 		    *buf++ = b[1];
 		    *buf++ = b[2];
 		    *buf++ = b[3];
 		} else {
 		    *buf++ = 0x83;
 		    *buf++ = b[1];
 		    *buf++ = b[2];
 		    *buf++ = b[3];
 		}
 	    } else {
 		*buf++ = 0x82;
 		*buf++ = b[2];
 		*buf++ = b[3];
 	    }
 	} else {
 	    *buf++ = 0x81;
 	    *buf++ = b[3];
 	}
     } else {
 	*buf++ = b[3];
     }
     return buf;
 }
 /*
  * XXX This should be rewritten, generalized, to take a long instead
  * of a PRInt32.
  */
 SECStatus
 DER_SetInteger(PLArenaPool *arena, SECItem *it, PRInt32 i)
 {
     unsigned char bb[4];
     unsigned len;
     bb[0] = (unsigned char) (i >> 24);
     bb[1] = (unsigned char) (i >> 16);
     bb[2] = (unsigned char) (i >> 8);
     bb[3] = (unsigned char) (i);
     /*
     ** Small integers are encoded in a single byte. Larger integers
     ** require progressively more space.
     */
     if (i < -128) {
 	if (i < -32768L) {
 	    if (i < -8388608L) {
 		len = 4;
 	    } else {
 		len = 3;
 	    }
 	} else {
 	    len = 2;
 	}
     } else if (i > 127) {
 	if (i > 32767L) {
 	    if (i > 8388607L) {
 		len = 4;
 	    } else {
 		len = 3;
 	    }
 	} else {
 	    len = 2;
 	}
     } else {
 	len = 1;
     }
     it->data = (unsigned char*) PORT_ArenaAlloc(arena, len);
     if (!it->data) {
 	return SECFailure;
     }
     it->len = len;
     PORT_Memcpy(it->data, bb + (4 - len), len);
     return SECSuccess;
 }
 /*
  * XXX This should be rewritten, generalized, to take an unsigned long instead
  * of a PRUint32.
  */
 SECStatus
 DER_SetUInteger(PLArenaPool *arena, SECItem *it, PRUint32 ui)
 {
     unsigned char bb[5];
     int len;
     bb[0] = 0;
     bb[1] = (unsigned char) (ui >> 24);
     bb[2] = (unsigned char) (ui >> 16);
     bb[3] = (unsigned char) (ui >> 8);
     bb[4] = (unsigned char) (ui);
     /*
     ** Small integers are encoded in a single byte. Larger integers
     ** require progressively more space.
     */
     if (ui > 0x7f) {
 	if (ui > 0x7fff) {
 	    if (ui > 0x7fffffL) {
 		if (ui >= 0x80000000L) {
 		    len = 5;
 		} else {
 		    len = 4;
 		}
 	    } else {
 		len = 3;
 	    }
 	} else {
 	    len = 2;
 	}
     } else {
 	len = 1;
     }
     it->data = (unsigned char *)PORT_ArenaAlloc(arena, len);
     if (it->data == NULL) {
 	return SECFailure;
     }
     it->len = len;
     PORT_Memcpy(it->data, bb + (sizeof(bb) - len), len);
     return SECSuccess;
 }
 /*
 ** Convert a der encoded *signed* integer into a machine integral value.
 ** If an underflow/overflow occurs, sets error code and returns min/max.
 */
 long
 DER_GetInteger(const SECItem *it)
 {
     long ival = 0;
     unsigned len = it->len;
     unsigned char *cp = it->data;
     unsigned long overflow = 0x1ffUL << (((sizeof(ival) - 1) * 8) - 1);
     unsigned long ofloinit;
     PORT_Assert(len);
     if (!len) {
 	PORT_SetError(SEC_ERROR_INPUT_LEN);
 	return 0;
     }
     if (*cp & 0x80)
     	ival = -1L;
     ofloinit = ival & overflow;
     while (len) {
 	if ((ival & overflow) != ofloinit) {
 	    PORT_SetError(SEC_ERROR_BAD_DER);
 	    if (ival < 0) {
 		return LONG_MIN;
 	    }
 	    return LONG_MAX;
 	}
 	ival = ival << 8;
 	ival |= *cp++;
 	--len;
     }
     return ival;
 }
 /*
 ** Convert a der encoded *unsigned* integer into a machine integral value.
 ** If an overflow occurs, sets error code and returns max.
 */
 unsigned long
 DER_GetUInteger(SECItem *it)
 {
     unsigned long ival = 0;
     unsigned len = it->len;
     unsigned char *cp = it->data;
     unsigned long overflow = 0xffUL << ((sizeof(ival) - 1) * 8);
     PORT_Assert(len);
     if (!len) {
 	PORT_SetError(SEC_ERROR_INPUT_LEN);
 	return 0;
     }
     /* Cannot put a negative value into an unsigned container. */
     if (*cp & 0x80) {
 	PORT_SetError(SEC_ERROR_BAD_DER);
 	return 0;
     }
     while (len) {
 	if (ival & overflow) {
 	    PORT_SetError(SEC_ERROR_BAD_DER);
 	    return ULONG_MAX;
 	}
 	ival = ival << 8;
 	ival |= *cp++;
 	--len;
     }
     return ival;
 }

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security/nss/lib/util/dersubr.c@b8a032363ba2 (annotated)

security/nss/lib/util/dersubr.c