1 files changed, 163 insertions, 52 deletions

diff --git a/src/lib/libcrypto/asn1/a_int.c b/src/lib/libcrypto/asn1/a_int.c
index df79cf99bb..d05436378b 100644
--- a/src/lib/libcrypto/asn1/a_int.c
+++ b/src/lib/libcrypto/asn1/a_int.c
@@ -58,17 +58,37 @@
 
 #include <stdio.h>
 #include "cryptlib.h"
-#include "asn1.h"
+#include <openssl/asn1.h>
 
-/* ASN1err(ASN1_F_D2I_ASN1_INTEGER,ASN1_R_EXPECTING_AN_INTEGER);
+/* 
+ * This converts an ASN1 INTEGER into its DER encoding.
+ * The internal representation is an ASN1_STRING whose data is a big endian
+ * representation of the value, ignoring the sign. The sign is determined by
+ * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative. 
+ *
+ * Positive integers are no problem: they are almost the same as the DER
+ * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
+ *
+ * Negative integers are a bit trickier...
+ * The DER representation of negative integers is in 2s complement form.
+ * The internal form is converted by complementing each octet and finally 
+ * adding one to the result. This can be done less messily with a little trick.
+ * If the internal form has trailing zeroes then they will become FF by the
+ * complement and 0 by the add one (due to carry) so just copy as many trailing 
+ * zeros to the destination as there are in the source. The carry will add one
+ * to the last none zero octet: so complement this octet and add one and finally
+ * complement any left over until you get to the start of the string.
+ *
+ * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
+ * with 0xff. However if the first byte is 0x80 and one of the following bytes
+ * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
+ * followed by optional zeros isn't padded.
  */
 
-int i2d_ASN1_INTEGER(a,pp)
-ASN1_INTEGER *a;
-unsigned char **pp;
+int i2d_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
         {
         int pad=0,ret,r,i,t;
-        unsigned char *p,*pt,*n,pb=0;
+        unsigned char *p,*n,pb=0;
 
         if ((a == NULL) || (a->data == NULL)) return(0);
         t=a->type;
@@ -78,16 +98,25 @@ unsigned char **pp;
                 {
                 ret=a->length;
                 i=a->data[0];
-                if ((t == V_ASN1_INTEGER) && (i > 127))
-                        {
+                if ((t == V_ASN1_INTEGER) && (i > 127)) {
                         pad=1;
                         pb=0;
+                } else if(t == V_ASN1_NEG_INTEGER) {
+                        if(i>128) {
+                                pad=1;
+                                pb=0xFF;
+                        } else if(i == 128) {
+                        /*
+                         * Special case: if any other bytes non zero we pad:
+                         * otherwise we don't.
+                         */
+                                for(i = 1; i < a->length; i++) if(a->data[i]) {
+                                                pad=1;
+                                                pb=0xFF;
+                                                break;
+                                }
                         }
-                else if ((t == V_ASN1_NEG_INTEGER) && (i>128))
-                        {
-                        pad=1;
-                        pb=0xFF;
-                        }
+                }
                 ret+=pad;
                 }
         r=ASN1_object_size(0,ret,V_ASN1_INTEGER);
@@ -96,33 +125,35 @@ unsigned char **pp;
 
         ASN1_put_object(&p,0,ret,V_ASN1_INTEGER,V_ASN1_UNIVERSAL);
         if (pad) *(p++)=pb;
-        if (a->length == 0)
-                *(p++)=0;
-        else if (t == V_ASN1_INTEGER)
-                {
-                memcpy(p,a->data,(unsigned int)a->length);
-                p+=a->length;
-                }
-        else
-                {
-                n=a->data;
-                pt=p;
-                for (i=a->length; i>0; i--)
-                        *(p++)= (*(n++)^0xFF)+1;
-                if (!pad) *pt|=0x80;
+        if (a->length == 0) *(p++)=0;
+        else if (t == V_ASN1_INTEGER) memcpy(p,a->data,(unsigned int)a->length);
+        else {
+                /* Begin at the end of the encoding */
+                n=a->data + a->length - 1;
+                p += a->length - 1;
+                i = a->length;
+                /* Copy zeros to destination as long as source is zero */
+                while(!*n) {
+                        *(p--) = 0;
+                        n--;
+                        i--;
                 }
+                /* Complement and increment next octet */
+                *(p--) = ((*(n--)) ^ 0xff) + 1;
+                i--;
+                /* Complement any octets left */
+                for(;i > 0; i--) *(p--) = *(n--) ^ 0xff;
+        }
 
-        *pp=p;
+        *pp+=r;
         return(r);
         }
 
-ASN1_INTEGER *d2i_ASN1_INTEGER(a, pp, length)
-ASN1_INTEGER **a;
-unsigned char **pp;
-long length;
+ASN1_INTEGER *d2i_ASN1_INTEGER(ASN1_INTEGER **a, unsigned char **pp,
+             long length)
         {
         ASN1_INTEGER *ret=NULL;
-        unsigned char *p,*to,*s;
+        unsigned char *p,*to,*s, *pend;
         long len;
         int inf,tag,xclass;
         int i;
@@ -137,6 +168,7 @@ long length;
 
         p= *pp;
         inf=ASN1_get_object(&p,&len,&tag,&xclass,length);
+        pend = p + len;
         if (inf & 0x80)
                 {
                 i=ASN1_R_BAD_OBJECT_HEADER;
@@ -161,16 +193,102 @@ long length;
         if (*p & 0x80) /* a negative number */
                 {
                 ret->type=V_ASN1_NEG_INTEGER;
-                if (*p == 0xff)
+                if ((*p == 0xff) && (len != 1)) {
+                        p++;
+                        len--;
+                }
+                i = len;
+                p += i - 1;
+                to += i - 1;
+                while((!*p) && i) {
+                        *(to--) = 0;
+                        i--;
+                        p--;
+                }
+                /* Special case: if all zeros then the number will be of
+                 * the form FF followed by n zero bytes: this corresponds to
+                 * 1 followed by n zero bytes. We've already written n zeros
+                 * so we just append an extra one and set the first byte to
+                 * a 1. This is treated separately because it is the only case
+                 * where the number of bytes is larger than len.
+                 */
+                if(!i) {
+                        *s = 1;
+                        s[len] = 0;
+                        len++;
+                } else {
+                        *(to--) = (*(p--) ^ 0xff) + 1;
+                        i--;
+                        for(;i > 0; i--) *(to--) = *(p--) ^ 0xff;
+                }
+        } else {
+                ret->type=V_ASN1_INTEGER;
+                if ((*p == 0) && (len != 1))
                         {
                         p++;
                         len--;
                         }
-                for (i=(int)len; i>0; i--)
-                        *(to++)= (*(p++)^0xFF)+1;
+                memcpy(s,p,(int)len);
+        }
+
+        if (ret->data != NULL) Free((char *)ret->data);
+        ret->data=s;
+        ret->length=(int)len;
+        if (a != NULL) (*a)=ret;
+        *pp=pend;
+        return(ret);
+err:
+        ASN1err(ASN1_F_D2I_ASN1_INTEGER,i);
+        if ((ret != NULL) && ((a == NULL) || (*a != ret)))
+                ASN1_INTEGER_free(ret);
+        return(NULL);
+        }
+
+/* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
+ * ASN1 integers: some broken software can encode a positive INTEGER
+ * with its MSB set as negative (it doesn't add a padding zero).
+ */
+
+ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, unsigned char **pp,
+             long length)
+        {
+        ASN1_INTEGER *ret=NULL;
+        unsigned char *p,*to,*s;
+        long len;
+        int inf,tag,xclass;
+        int i;
+
+        if ((a == NULL) || ((*a) == NULL))
+                {
+                if ((ret=ASN1_INTEGER_new()) == NULL) return(NULL);
+                ret->type=V_ASN1_INTEGER;
                 }
         else
+                ret=(*a);
+
+        p= *pp;
+        inf=ASN1_get_object(&p,&len,&tag,&xclass,length);
+        if (inf & 0x80)
+                {
+                i=ASN1_R_BAD_OBJECT_HEADER;
+                goto err;
+                }
+
+        if (tag != V_ASN1_INTEGER)
                 {
+                i=ASN1_R_EXPECTING_AN_INTEGER;
+                goto err;
+                }
+
+        /* We must Malloc stuff, even for 0 bytes otherwise it
+         * signifies a missing NULL parameter. */
+        s=(unsigned char *)Malloc((int)len+1);
+        if (s == NULL)
+                {
+                i=ERR_R_MALLOC_FAILURE;
+                goto err;
+                }
+        to=s;
                 ret->type=V_ASN1_INTEGER;
                 if ((*p == 0) && (len != 1))
                         {
@@ -179,7 +297,6 @@ long length;
                         }
                 memcpy(s,p,(int)len);
                 p+=len;
-                }
 
         if (ret->data != NULL) Free((char *)ret->data);
         ret->data=s;
@@ -188,15 +305,13 @@ long length;
         *pp=p;
         return(ret);
 err:
-        ASN1err(ASN1_F_D2I_ASN1_INTEGER,i);
+        ASN1err(ASN1_F_D2I_ASN1_UINTEGER,i);
         if ((ret != NULL) && ((a == NULL) || (*a != ret)))
                 ASN1_INTEGER_free(ret);
         return(NULL);
         }
 
-int ASN1_INTEGER_set(a,v)
-ASN1_INTEGER *a;
-long v;
+int ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
         {
         int i,j,k;
         unsigned char buf[sizeof(long)+1];
@@ -229,15 +344,13 @@ long v;
                 d>>=8;
                 }
         j=0;
-        if (v < 0) a->data[j++]=0;
         for (k=i-1; k >=0; k--)
                 a->data[j++]=buf[k];
         a->length=j;
         return(1);
         }
 
-long ASN1_INTEGER_get(a)
-ASN1_INTEGER *a;
+long ASN1_INTEGER_get(ASN1_INTEGER *a)
         {
         int neg=0,i;
         long r=0;
@@ -266,9 +379,7 @@ ASN1_INTEGER *a;
         return(r);
         }
 
-ASN1_INTEGER *BN_to_ASN1_INTEGER(bn,ai)
-BIGNUM *bn;
-ASN1_INTEGER *ai;
+ASN1_INTEGER *BN_to_ASN1_INTEGER(BIGNUM *bn, ASN1_INTEGER *ai)
         {
         ASN1_INTEGER *ret;
         int len,j;
@@ -279,10 +390,11 @@ ASN1_INTEGER *ai;
                 ret=ai;
         if (ret == NULL)
                 {
-                ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ASN1_R_ERROR_STACK);
+                ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_NESTED_ASN1_ERROR);
                 goto err;
                 }
-        ret->type=V_ASN1_INTEGER;
+        if(bn->neg) ret->type = V_ASN1_NEG_INTEGER;
+        else ret->type=V_ASN1_INTEGER;
         j=BN_num_bits(bn);
         len=((j == 0)?0:((j/8)+1));
         ret->data=(unsigned char *)Malloc(len+4);
@@ -293,13 +405,12 @@ err:
         return(NULL);
         }
 
-BIGNUM *ASN1_INTEGER_to_BN(ai,bn)
-ASN1_INTEGER *ai;
-BIGNUM *bn;
+BIGNUM *ASN1_INTEGER_to_BN(ASN1_INTEGER *ai, BIGNUM *bn)
         {
         BIGNUM *ret;
 
         if ((ret=BN_bin2bn(ai->data,ai->length,bn)) == NULL)
                 ASN1err(ASN1_F_ASN1_INTEGER_TO_BN,ASN1_R_BN_LIB);
+        if(ai->type == V_ASN1_NEG_INTEGER) bn->neg = 1;
         return(ret);
         }